Viral diseases of Cattle

Bovine Viral Diarrhoea (BVD) and Mucosal Disease (MD)

BVD is caused by the BVD Virus (a Pestivirus, family Flaviviridae). Two immunologically different genotypes of BVDV have been described, type 1 and type 2, as well as several subtypes within each genotype. To date, only genotype 1 has been isolated from cattle in southern Africa. Both genotypes have cytopathic and non-cytopathic strains. The non-cytopathic strain is the more common form of the virus and can cross the placenta to infect the foetus and also infect the testes of bulls.

The virus can spread:

• Horizontally – inhalation or ingestion of virus from body secretions or excretions of infected animals. Horizontal spread leads to transient infection (TI) that lasts for less than 2 weeks.
• Vertically – dam to the foetus. Because of this, the disease remains in an infected herd unless carriers are removed. Vertical spread led to permanently infected (PI) animals that are a constant source of infection in the herd.

MD is an uncommon but highly fatal form of BVD occurring in persistently infected (PI) cattle and can have an acute or chronic presentation. MD is induced when PI cattle become superinfected (a second infection by another microbial agent) with cytopathic (producing pathological changes in cells) BVDV.

• The name bovine viral diarrhoea is misleading in that the disease does not specifically affect the digestive tract (i.e., diarrhoea is probably of less importance) but rather has immune suppression as a hallmark sign.
• Reproductive failure due to infection during or after breeding.
• BVDV infection after birth (TI) presents most commonly as bacterial pneumonia.
• Infection during mid-to-late-term pregnancy may lead to abortion or the birth of an abnormal or weak calf. Abnormalities such as blindness and calves with an underdeveloped cerebellum, which is presented as a calf that cannot stand or walk, or in milder cases appear drunk.

Other symptoms may include:

• Fever (41 – 42 °C).
• Lethargy and depression.
• Loss of appetite.
• Rapid breathing.
• Dehydration.
• Ocular discharge or excessive lacrimation.
• Excessive nasal discharge.
• leukopenia, and thrombocytopenia (low blood platelet level
• Petechial haemorrhages may be seen in the conjunctiva, sclera, nictitating membrane of the eyes, and mucosal surfaces of the mouth and vulva.
• Oral lesions or ulcerations
• Decreasing milk production.
• Prolonged bleeding from injection sites.

• Treatment of BVD remains limited primarily to supportive therapy.
• Improved biosecurity and vaccines are used to control and prevent outbreaks.
• When new animals are brought, they should be kept under quarantine for 2 – 3 weeks and tested for BVD PI status before introducing them into the herd. If pregnant animals are bought, their calves should be tested for BVD PI status.
• The vaccination programme for each herd should be designed in collaboration with the herd veterinarian.

MSD Animal Health Vaccines:

Ø  Bovi-Tect III.

Ø  Bovilis® Vista Once SQ.

Ø  Respiravax.

• In the case of calves, the best protection is achieved when all calves are vaccinated with a modified live virus (MLV) twice, with an interval of 4 weeks. The first vaccination must be after 4 months of age, and the second must be at least 2 weeks before a stressful event such as weaning or transport.
• For breeding cows, heifers and bulls, the best protection is achieved when animals are vaccinated twice with an interval of 4 weeks, the second vaccination being at least 1 month before the first breeding season and boosted yearly before the start of breeding. This should be done using an MLV vaccine every time, and in bulls, only a cytopathic strain of MLV must be used.

Description of Viral Disease

Symptoms

Treatment, Prevention and Control

Foot-and-Mouth Disease
(FMD; “Bek-en-klouseer”)

A highly transmissible disease caused by infection with an Aphthovirus, a member of the family Picornaviridae. There are 7 serotypes of the virus, termed: A, O, C, Asia 1, and SAT (Southern African Territories) 1, 2, and 3.

FMD is transmitted in the following ways:

• Direct contact with infected animals.
• Contact with contaminated secretions or excretions (including semen and milk) from infected animals.
• FMD virus is shed into milk in dairy cows before clinical signs develop, so there is an opportunity for the virus to spread from farm to farm and from cow to calf via raw milk. FMD virus may survive pasteurisation depending on the method (high-temperature short time, ultra-high temperature, laboratory pasteurisation); the lipid component of milk protects the virus during heating.
• Inhalation, ingestion of feed from infected animals (meat and offal), or through skin wounds and mucous membranes.
• Mechanical vectors (people, horses, dogs, cats, birds, vehicles). People can act as mechanical vectors of FMD by carrying the virus on clothing or skin. However, FMD is not considered a public health problem.
• Air movement over land or water.

• A fever of ~40 °C.
• Vesicular lesion development on the tongue, hard palate, dental pad, lips, gums, muzzle, coronary band, interdigital cleft, and teats in lactating cows. Ruptured oral vesicles can coalesce and form erosions but heal rapidly, roughly 11 days after vesicle formation.

  

• Vesicles on the feet take longer to heal and are susceptible to bacterial infection leading to chronic lameness.

  

• Acutely affected individuals may salivate profusely (drooling), stamp their feet, and prefer to lie down.

  
  See video below

• Secondary bacterial mastitis is common due to infected teat vesicles resulting in resistance to milking.
• After vesicular disease develops, cattle quickly lose condition and milk yield diminishes, which can persist chronically.
• Occasionally, young calves may die without prior clinical signs of illness because of virus-induced damage to the developing myocardium (the muscular layer of the heart).

• In FMD-free regions, control typically involves culling all infected and susceptible animals in infected herds or on infected premises, proper carcass disposal, environmental disinfection, and movement controls (strict restriction of animal and vehicle movement around infected premises) are imposed to reduce the risk of virus spread.
• In both normally FMD-free regions and endemic areas, vaccination around outbreaks may be used to limit the spread of the disease. Inactivated virus vaccines protect for only 4–6 months against the specific serotype(s) contained in the vaccine.
• No treatments for infected animals are available.
• Rapid disease reporting is essential to control an FMD outbreak in nonendemic countries.
• When mass culling is performed, infected carcasses must be disposed of via incineration, burial, or rendering on or close to the infected premises.
• Scavengers and rodents should be prevented or killed to prevent the mechanical dissemination of the virus.
• Buildings should be cleaned with a mild acid or alkaline disinfectant and fumigation.
• People who have come into contact with the virus must decontaminate their clothing and avoid contact with susceptible animals for some time.
• Fencing of wildlife reserves to prevent contact with domestic livestock. A twice-yearly vaccination buffer zone in livestock near endemic wildlife reserves may additionally help reduce outbreaks.

FOOT-AND-MOUTH DISEASE OUTBREAK IN SOUTH AFRICA

South Africa is currently battling 116 outbreak cases of foot-and-mouth disease (FMD) in the previous FMD-free zones. These outbreaks are comprised of 3 outbreak events:

1. The 1^st event started in May 2021 and is affecting KwaZulu-Natal (KZN) Province.

2. The 2^nd outbreak event started in March 2022 in the previous free zone in Limpopo Province.

3. The 3^rd outbreak event also started in March 2022 in North West Province, with spread to Free State, Gauteng and Mpumalanga Provinces.

To halt the spread of FMD, a National movement ban on cattle was instituted on 16 August 2022. This restriction will remain in place for only a short period until the current exponential spread of FMD has been stopped.

The implications of the movement ban include:

• Cattle may not be moved from one property to another for any reason, except for direct slaughter at a registered abattoir.
• No cattle may be moved between farms, locations or premises for purposes of sale, shows, breeding, backgrounding, ritual purposes, lobola, or any other purpose.
• No cattle may be moved into feedlots, and movement out of feedlots is only allowed directly to registered abattoirs.
• No cattle may be moved for import or export.

All affected farms and feedlots in North West, Free State, Gauteng and Mpumalanga are currently under quarantine with strict access control. The locations involved are well-fenced and the movement of animals from these farms can be effectively prevented.

To curtail the spread of the disease, vaccination campaigns have been initiated in affected provinces.

Description of Viral Disease

Symptoms

Treatment, Prevention and Control

Lumpy skin disease (LSD; “Knopvelsiekte”)

An infectious, eruptive, occasionally fatal disease of cattle characterised by nodules (growth of abnormal tissue) on the skin and other parts of the body. Secondary bacterial infection often aggravates the condition.

The causal virus is related to the sheep pox virus. LSD is caused by a Capripox Virus of the Poxvirus family. Lumpy skin disease appears epidemically or sporadically.

Its incidence is highest in wet summer weather, but it may occur in winter. It is most prevalent along water courses and on low ground.

Biting insects play a role in the transmission of LSD.

This disease often occurs in tandem with Senkobo disease in the tropics (Africa).

LSD is an acute, subacute or inapparent disease characterised by:

• A biphasic febrile response.
• Circumscribed skin nodules spread over the body and vary in size from 5 – 50 mm in diameter.

  
  

• Necrotic plaques on the mucous membranes.
• Swelling of lymph nodes.
• Inappetence.
• Salivation.
• Lachrymation (flow of tears).
• A mucoid or mucopurulent nasal discharge.
• Emaciation.
• Decreased milk production.
• Infertility in bulls and cows.
• Damage to hides.

• Because biting insects are involved in the spread of the disease it will not help to control the movement of animals.
• Immunoprophylaxis (the use of vaccines or antibody-containing preparations to provide a susceptible individual with immunologic protection against a specific disease) is the only effective way of controlling the disease in South Africa.
• Annual vaccination is recommended.

MSD Animal Health vaccine:

Ø  Lumpyvax®.

Malignant catarrhal fever (MCF; “Snotsiekte”)

A sporadic, invariably fatal viral disease caused by one of several members of a group of closely related ruminant gamma herpesviruses of the Macavirus genus. Although the MCF group of ruminant rhadinoviruses currently comprises ~10 known members, only a few are known to be pathogenic under natural conditions. The principal carriers and their viruses are sheep (ovine herpesvirus-2), wildebeest (alcelaphine herpesvirus-1), and goats (caprine herpesvirus-2). Virtually all clinical cases are caused by the sheep or wildebeest viruses.

In other words, MCF may occur when cattle are housed with sheep or goats and in Africa occurs more often as a result of contact with blue or black wildebeest. Sheep, goats and wildebeest are persistently infected carriers of the causative virus without themselves developing any signs of the disease.

Wildebeest calves up to 4 months of age are important in the transmission of MCF as they excrete the virus in their nasal and ocular discharges. In South Africa, two peaks in the incidence of MCF are seen, one in January to May following the wildebeest calving season in December to February, and a second where the incidence is higher, from September to November. At the latter time, wildebeest calves are up to 11 months old.

• A sudden sharp rise in temperature reaching a peak of about 41.6 °C by the 3^rd or 4^th day of the disease.
• A bilateral nasal discharge. The discharge becomes thick, copious and mucopurulent. The discharge will encrust the nostrils and muzzle of the animal.

  

• Usually, the eyes begin to swell and develop a clear discharge. A severe inflammation then develops with a discharge of pus and corneal opacity (grey appearance of the eye). Their eyes become crusted with dried exudate.

  

• Breathing becomes difficult and laboured (dyspnoea).
• Affected animals are completely unproductive.
• Affected animals die within 4 – 5 days after the onset of symptoms.

• No treatment has been found to provide any consistent benefit.
• Reduce stress reduction of subclinical or mildly affected animals.
• Supportive care.
• Early weaning and isolation.
• The only effective way to prevent the disease is to separate cattle from reservoir hosts with the aid of a corridor at least 1 km wide.
• In South Africa, MCF is no longer a controlled disease.
• There is no vaccine for this disease.

Pneumonia (“Longontsteking”)

Numerous factors lead to pneumonia in cattle. One microorganism alone cannot be held responsible for pneumonia.

The environment always contains several viruses. A virus survives longer in a colder, wetter climate and always originates from a carrier animal.

IBR, BVDV, BRSV, and PI-3 are all viruses that are typical primary causes of pneumonia in cattle.

Infectious bovine rhinotracheitis (IBR)

A highly contagious disease of the upper respiratory tract that can lead to serious primary or secondary pneumonia. It can affect young and older cattle.

IBR is a viral disease caused by Bovine Herpesvirus type 1 (BHV-1) that can also cause a mild venereal infection in adult cattle or a brain infection in calves.

Diseases caused by the virus can be serious; therefore, it is a barrier to international trade. Cattle with BoHV-1 antibodies cannot be exported to BoHV-1-free countries. Neither can they be accepted into artificial insemination (AI) centres.

Animas infected with BHV-1 remain infected and shed the virus throughout their lives, particularly at times of stress, such as another disease, calving, transport, and so forth.

The virus is spread through:

• Sexual conduct.
• Artificial insemination (AI).
• Aerosol transmission.

The source of infection in a herd that has not been exposed to BHV-1 is the introduction of a BHV-1 carrier.

• Nasal discharge.

  

• Red nose – hyperaemia and inflamed nasal mucosa.

  

• Mucosa lesions.
• Loss of appetite.
• Fever.
• Coughing.
• Conjunctivitis.
• Depression.
• Decreased milk production.
• Infertility.
• Abortion.
• Animals suffering from IBR are highly susceptible to secondary bacterial infections.

• There is no direct or specific treatment for IBR-infected cattle. During an outbreak, infected animals should be isolated from the rest of the herd and treated with anti-inflammatory drugs and broad-spectrum, long-acting antibiotics to prevent secondary bacterial pneumonia. Carrier cattle should be identified and removed from the herd.
• Control of the disease is based on the use of vaccines. Vaccination is an effective way of controlling the disease but it does not stop infected animals from shedding the virus and is no guarantee against the introduction of the disease into a herd.
• Vaccination is recommended as soon as passive immunity in calves has disappeared, usually around 4 – 6 months of age. Since maximum protection does not generally occur until approximately 3 weeks after vaccination, calves should be vaccinated 2 to 3 weeks before weaning at which time they start to be at risk of infection.
• Single vaccination will reduce the severity of the disease, but not provide complete protection.

MSD Animal Health Vaccines:

Ø  Bovi-Tect III.

Ø  Bovi-Tect PI.

Ø  Bovilis® Vista Once SQ.

Ø  Respiravax.

• Appropriate biosecurity will also reduce risk on the farm.

Bovine Respiratory Syncytial Virus (BRSV)

BRSV was named for its characteristic cytopathic effect, the formation in infected tissue of syncytial cells and giant multinuclear cells formed by the fusion of several cells. BRSV has a preference for the lower respiratory tract, where it can cause varying degrees of pneumonia by itself. Secondary bacterial infections, frequently involving Mannheimia (Pasteurella) haemolytica, cause diseases of greater severity or death.

Transmission occurs through respiratory aerosols or direct contact with infected cattle.

BRSV infects the mucosal cells lining the respiratory tract, destroying the mucociliary apparatus that clears pathogens and particulate matter from the airways. This process leaves the underlying tissue vulnerable to viral infection and secondary bacterial infection.

Clinical infection produces:

• High fever (40° – 42°C).
• Increased respiratory rate.
• Spontaneous coughing.
• Nasal and lacrimal discharge.
• Depression.
• Decreased feed intake.
• Most cases recover naturally.

• There is no specific anti-BRSV therapy.  Treatment is limited to antibacterial therapy for secondary bacterial infections and supportive treatment.
• Vaccination may prevent, help prevent, control, or lessen the severity of the disease.

MSD Animal Health Vaccine:

Ø  Bovilis® Vista Once SQ.

Parainfluenza 3-Virus (PI-3)

The PI-3 virus infects the upper respiratory mucosa, where it is shed in aerosols and by direct contact. Unlike IBR (BHV-1) and BVDV, PI-3 is responsible only for respiratory disease. In mature cattle, uncomplicated PI-3 infection is usually associated with mild or subclinical disease. Fatalities are rare and usually involve secondary bacterial infections.

PI-3 predisposes cattle to concurrent infections with the IBR virus or bacterial respiratory pathogens.

 Symptoms include the classic respiratory signs of:

• Cough.
• Fever.
• Serous nasal and ocular discharge.
• Increased respiratory rate.
• Dyspnoea.

• There is no specific anti-PI3 therapy. Treatment is limited to antibacterial therapy for secondary bacterial infections and supportive treatment.
• Vaccination may help prevent, control, or lessen the severity of the disease.

MSD Animal Health Vaccines:

Ø  Bovilis® Vista Once SQ.

Ø  Respiravax.

Three-Day Stiffness
(Bovine ephemeral fever – BEF)

An insect-transmitted, noncontagious, viral disease caused by the Bovine ephemeral fever virus (BEFV), which is classified as a member of the genus Ephemerovirus in the family Rhabdoviridae.

The virus is ether-sensitive and readily inactivated at pH levels < 5 and > 10.

The disease is characterised by a short duration, and in most cases, there is complete recovery in the animals.

Seasonal occurrence of BEF suggests that BEF is transmitted by insects. In South Africa, cases of BEF are most common in the second half of summer.

Signs of BEF, which occur suddenly and vary in severity, can include:

• Biphasic to polyphasic fever – i.e., boing from having two phases to more than one phase (40 – 42 °C).
• Shivering.
• Inappetence.
• Tearing.
• Serous nasal discharge.

  

• Drooling.
• Pulmonary emphysema (a chronic lung condition that involves difficult breathing).
• Increased heart rate.
• Tachypnoea (abnormally rapid breathing) or dyspnoea.
• Atony (muscular weakness) of the forestomach.
• Depression.

  

• Stiffness and lameness.
• A sudden decrease in milk yield.

Symptoms may disappear as fast as they appeared. Affected animals do not return to normal production after recovery.

• Treatment may include rest, anti-inflammatories and antibiotic treatment to prevent secondary infections.
• It is important to vaccinate animals in endemic areas.

Bovine leukosis (Leukemia; Bovine lymphosarcoma; Malignant lymphoma)

A viral disease that occurs worldwide. The disease occurs in two forms:
1) Enzootic bovine leukosis – is caused by Bovine Leukaemia Virus (BLV) and is found in adult cattle of 5 – 8 years old.

2) Sporadic bovine leukosis – not associated with the BLV and occurs in young calves between 4 months and 2 years.

The mechanical transfer of blood through needles, surgical procedures and insects are more common mechanisms of transmission.

Symptoms associated with the development of lymphosarcoma are highly variable because the affected organ(s) will dictate the predominant symptoms.

Juvenile lymphosarcoma:

• Weight loss.
• Fever.
• Increased heart rate (tachycardia).
• Dyspnoea.
• Bloat.
• Posterior paresis.

Thymic lymphosarcoma:

• Dyspnoea.
• Bloat.
• Jugular distention.
• Increased heart rate (tachycardia).
• Anterior oedema.
• Fever.

Cutaneous lymphosarcoma:

• Cutaneous plaques, 1–5 cm in diameter, on the neck, back, rump, and thighs.
• Regional lymph nodes may also be enlarged. This form of lymphosarcoma may undergo spontaneous remission; however, relapses may occur.

Post-mortem examination:

Enzootic bovine leukosis is characterised by:

Discrete, solid tumour masses in many tissues or organs, especially the lymph nodes, heart, abomasum, kidneys, intestines, and uterus.

Sporadic bovine leukosis is characterised by generalised lymph node enlargement, tumour development in the thymus gland, or tumours in the skin.

• There is no treatment.
• Positive animals must be removed from the herd if a clean herd is to be established (slaughter out policy).

Bovine papillomavirus (BPV; Bovine warts; “Vratte”)

BPVs produce generally harmless (i.e., benign) tumours of the skin and the mucous membranes of the alimentary and urogenital tracts. The tumours, which may be papillomas or fibro papillomas, are commonly called warts. In many cases, viruses have been proven responsible.

Cattle of all ages are affected by warts, but they occur most commonly in young calves and yearlings. The disease is more common in animals that are housed or penned. There is no sex or breed predilection.

Husbandry practices may spread fibropapillomas within a herd. Cases of spread have been recorded after tattooing, tuberculin testing, pregnancy testing by rectal palpation, and dehorning.

• The warts are usually found on the skin around the eyes, mouth, and the sides of the neck and the shoulders in beef cattle, while dairy cattle often develop them on the udders and teats.
• Symptoms vary from small nodules to large cauliflower-like growths that often coalesce to form large masses, which then become necrotic (dead) and develop a putrid smell.
• Warts regress spontaneously after a few months and by 2 years of age, they have usually disappeared.

  

Papillomatosis is generally a mild, self-limiting disease and therefore neither prevention nor treatment is usually necessary.

Occasionally, however, epidemics in young cattle do occur and some individuals may be so severely affected that their growth is retarded. In such circumstances, a variety of treatments have been tried, but there is a lack of unanimity, not to mention reliable evidence, as to the efficacy of these treatments, for example:

• The crushing of warts on the animal so that the virus enters the bloodstream and increases the immune response of the animal.

A vaccine can be produced by some laboratories using wart tissues from an animal on the same premises, but the results are variable and complications such as the development of tumours at the injection site have been described.

Cowpox

A mild, eruptive, and currently rare viral disease of cattle (especially dairy cattle) resulting in vesicles, purulent areas and scabs on the teats and udders of cattle.

The primary host of this virus is wild rodents. Humans are occasional hosts.

The disease spreads mechanically by contact during milking. The virus is sensitive to fat solvents, hypochlorite and QAC compounds found in most teat disinfectants.

Cowpox is an important cause of zoonosis. People attending the infected cattle may develop fever and have lesions on the hands, arms, or face. Occasionally, cowpox in people can cause generalised disease, and fatalities have been recorded.

• A mild febrile reaction during the incubation period of 3 – 7 days.
• Papules appear on the teats and udder.
• Vesicles may not be evident or may rupture readily, leaving raw, ulcerated areas that form scabs.

  

• Milk production will be affected in the initial phases of the disease.
• Infected teat pustules left untreated may result in secondary mastitis.

Lesions heal within 1 month. Most cows in a milking herd may become affected.

• There is no specific treatment.
• Once infected, immunity is lifelong and recovery generally happens very quickly.
• Proper hygiene and isolation management will limit the impact of the disease.
• Pasteurised milk from infected animals is safe to drink.

Pseudo cowpox
(False cowpox; Milker’s nodule)

Mild infection of the udder and teats of cows caused by a Para poxvirus, which is related to those of contagious ecthyma (orf).

This disease is far more common than cowpox.

• Lesions of pseudo cowpox begin as small, red papules on the teats or udder.
• These may be followed rapidly by scabbing, but small vesicles or pustules may develop before scabs form.
• Scabs may be abundant and can be removed without causing pain. Granulation occurs beneath the scabs, resulting in a raised lesion that heals from the centre and leaves a characteristic horseshoe or circular ring of small scabs. This stage is reached in ~7 – 12 days.
• Some lesions persist for several months, giving the affected teats a rough feel and appearance, and more scabs may form.

The scabbed lesions may be confused with mild traumatic injuries to the teats and udder.

The infection spreads slowly throughout milking herds, and a variable percentage of cows show lesions at any time. Cattle may become reinfected in subsequent lactations.

• Removal of the scabs followed by the application of an astringent disinfectant has been suggested for severely affected individual cases.
• Locally applied teat ointments appear to have little effect. Emollient teat sprays and dips can have a beneficial effect by reducing the number of bacteria and viruses on the teat skin and by aiding the healing of damaged skin.
• Control is achieved by practising good hygiene management in milking parlours (such as teat dipping) and preventing mechanical transmission through good fly control and topical treatment of lesions.
• Little immunity appears to develop.
• People may become infected with painless, but itchy, purplish-red nodules that are generally present on the fingers or hands. These lesions cause little disturbance and disappear after several weeks.

Rabies (“Hondsdolheid”)

An acute, progressive viral encephalomyelitis (inflammation of the brain and spinal cord) transmitted from animal to animal by:

• The bite of one suffering from the disease.
• Contact with a rabid animal.
• Contact with one excreting the virus.

Transmission to domestic animals and man is usually through the bite of a rabid dog, fox, jackal, or mongoose.

The virus deposited in the wound by the bite travels via the nerves to the brain, where it is responsible for damage to the brain cells leading to the typical symptoms of rabies.

The disease is fatal once clinical signs appear.

The course of the disease may be divided into three stages:

Prodromal stage (2 – 3 days)

• Changes in behaviour.
• Depraved appetite.

Excitement stage (up to 3 days)

• Attempts to bite.
• Aimless compulsive activity.
• Changes in the voice.

Paralytic stage (up to 2 days)

• Paralysis of the lower jaw, hindquarters, throat, and masseter muscle (muscles of mastication or chewing) often with profuse salivation and the inability to swallow.

The transition from one stage to another is not necessarily clear because of the variability of signs and the irregular lengths of the stages. The disease progresses rapidly after the onset of paralysis, and death is virtually certain a few days thereafter. Some animals die rapidly without marked symptoms.

Other symptoms in cattle may include:

• Unsuccessful attempts to drink water.
• Aggressiveness – attacking and pursuing people and other animals.
• Frequent bellowing.
• Excessive salivation.
• Staring of and paralysis in the hindquarters.
• Lactation ceases abruptly in dairy cattle.

The usual placid expression is replaced by one of alertness. The eyes and ears follow sounds and movements.

• Rabies is a controlled disease in South Africa. All suspected outbreaks should be reported to a state veterinarian for further investigation.
• Treatment of affected animals is of no avail. Such animals should be culled.
• Oral vaccination of wildlife can reduce rabies in reservoir populations.
• Domestic dog management – notification of suspected cases and euthanasia of affected dogs, reduction of contact rates, immunisation of dogs, stray dog control, and dog registration.
• Vaccination. Recommended vaccination frequency is every 3 years, after an initial series of two vaccines 1 year apart.

MSD Animal Health Vaccines:

Ø  NOBIVAC® RABIES

NOBIVAC® RABIES is for the active immunisation of healthy dogs, cats, cattle, sheep, goats, ferrets, foxes, and horses, and in principle all healthy mammals against rabies. NOBIVAC® RABIES is only for use by or under the supervision of persons registered or authorised in terms of section 23 (1) (c) of the Veterinary and Para-Veterinary Professions Act, 1982 (Act 19 of 1982).

Rift Valley fever (RVF; “Slendalkoors”)

A per acute or acute, mosquito-borne, zoonotic disease caused by the RVF virus, which belongs to the genus Phlebovirus and is a typical Bunyavirus (a family of arthropod-borne or rodent-borne viruses).

Large outbreaks of clinical disease are usually associated with heavy rainfall and localised flooding due to dam building or flood irrigation.

Humans can become infected from contact with the tissues of infected animals or the bite of an infected mosquito.

Calves show symptoms such as:

• Biphasic fever of up to 42 °C may develop.
• Affected calves are listless and reluctant to move or feed.
• Signs of abdominal pain.
• Icterus (or jaundice – yellowing of the skin or whites of the eyes, arising from excess of the pigment bilirubin, typically caused by obstruction of the bile duct, liver disease, or excessive breakdown of red blood cells).
• Mortality may be as high as 70%.

Disease in adult cattle is often inapparent, but they may show:

• Anorexia.
• Lacrimation.
• Salivation.
• Nasal discharge.
• Dysgalactia – decreased secretion or production of milk.
• Abortion rates in cattle are usually <10%. Animals may abort during any stage of the pregnancy because of the febrile reaction. Sometimes, abortion may be the only sign of infection. The aborted foetus is usually autolysed (cells are destroyed through the action of enzymes).
• Stiffness of the legs.
• Bloody-stained or fetid diarrhoea.
• Mortality of 5 – 10%.

In people, RVF is usually inapparent or associated with a self-limiting febrile illness characterised by:

• Abrupt onset of malaise (a general sense of being unwell, often accompanied by fatigue, diffuse pain or lack of interest in activities)
• Myalgia (muscle aches and pain).
• Arthralgia (joint stiffness).
• A minority (1 – 2%) may develop severe disease with:
• Ocular lesions.
• Encephalitis.
• Severe hepatic lesions with haemorrhages.

In such cases, the fatality rate may be 10 – 20%.

• There is no treatment for this viral disease. Any animal suspected of having Rift Valley Fever should be reported to the State Veterinarians as RVF is a notifiable disease.
• Immunisation remains the only effective way to protect livestock from RVF:
• Offspring of vaccinated dams should be vaccinated at 3 – 6 months of age.
• Offspring of susceptible (unvaccinated) dams may be vaccinated at any age.
• An initial dose followed by a second booster vaccination 3 – 4 weeks after the first dose is recommended for an inactivated vaccine.
• Annual vaccination is recommended before the onset of the rainy season.
• Appropriate protective measures should be taken when investigating cases of abortion, handling potentially infected animals, and collecting diagnostic samples.
• Vector control.
• Do not slaughter sick animals or eat meat from sick animals.
• Boil or pasteurise milk before use and cook meat well before you eat it.

Rinderpest (Cattle plague)

An acute to peracute viral (Morbillivirus) disease of cloven-hoofed animals.

The characteristic signs of the disease occur in the mucous membranes – serious inflammation and consequent sloughing of dead tissue in the mouth, nasal passages, eyes, gastrointestinal tract, and respiratory tract.

• High fever.
• Depression and dullness.
• Inappetence.
• Decreased milk yield.
• Membranes of the eyes and mouth are intensely inflamed.
• Haemorrhages and ulcers are seen on the mucous membranes of the mouth.
• Ropy, foul-smelling saliva is discharged.
• Purulent nasal discharge.
• Coughing.
• Rapid breathing.
• Severe diarrhoea, sometimes bloodstained, leads to dehydration and death.
• The mortality in susceptible animals is almost 100%.

• South Africa has been Rinderpest-free since 1905. This is a controlled disease.
• In case of an outbreak, a complete slaughter-out policy will be put in place.
• Treatment of animals will not be done in an outbreak in South Africa.
• Whenever there is any suspicion of Rinderpest, the appropriate veterinary advice should be sought at the earliest opportunity to prevent further spread.
• Vaccination of healthy cattle in areas where the disease is known to exist, however, vaccination is not allowed in South Africa.

Sweating sickness (“Nat kalwersiekte”)

An acute, febrile, tickborne toxicosis. It is essentially a disease of young calves, although adult cattle are also susceptible.

The cause of sweating sickness is a toxin produced by female ticks of certain strains of the bont-legged tick, Hyalomma truncatum.

• Hyperthermia – an abnormally high body temperature (i.e., overheating).
• Anorexia.
• Listlessness.
• Watering of the eyes and nose.
• Hyperaemia (an excess of blood in the vessels supplying an organ or other part of the body) of the visible mucous membranes.
• Salivation
• Necrosis of the oral mucosa.
• Hyperesthesia – increased sensitivity of sight and smell and to sound and touch.
• Later, the eyelids stick together.
• The skin feels hot, and moist dermatitis soon develops, starting from the base of the ears, the axillae, groin, and perineum and extending over the entire body.
• The hair becomes matted, and beads of moisture may be seen on it.
• The skin becomes extremely sensitive and emits a sour odour.
• Later, the hair and epidermis can be readily pulled off, exposing red, raw wounds.
• The tips of the ears and the tail may slough.
• Eventually, the skin becomes hard and cracked and predisposed to secondary infection or screwworm infestation.
• Affected animals are sensitive to handling, show pain when moving, and seek shade.
• Often, the course is rapid, and death may occur within a few days. In less acute cases, the course is more protracted and recovery may occur. Mortality in affected calves is 30 – 70% under natural conditions.

The severity of infection is influenced by the number of ticks as well as by the length of time they remain on the host.

• Removal of ticks, symptomatic treatment, and good nursing care are indicated.
• Non-nephrotoxic antibiotics and anti-inflammatory agents are useful to combat secondary infection.
• Control of tick infestation is the only effective preventive measure. Adult ticks show a predilection to attach to the tail switch.

Babesiosis (Redwater)

An infection with tick-borne protozoa belonging to the genus Babesia which predominantly parasitises the erythrocytes of their host.

Cattle may be infected with several different Babesia spp., some of which are pathogenic (cause severe disease and mortality) whereas others may be of little economic importance.

The pathogenic species are:

1.    Babesia bigemina

This protozoan parasite causes African redwater, which occurs widely throughout Africa and is clinically more commonly associated with haemoglobinuria (a condition in which the oxygen transport protein haemoglobin is found in abnormally high concentrations in the urine).

This protozoan parasite is transmitted by:

• Rhipicephalus (Boophilus) decoloratus.
• R. (B.) microplus.
• Possibly, but certainly to a much lesser extent, by R. evertsi evertsi.

2.    Babesia bovis

This protozoan parasite causes Asiatic redwater, which has a more restricted distribution in Africa, being confined to the higher rainfall areas, and also occurs in most tropical and subtropical parts of the world.

This protozoan parasite is transmitted only by R. (B.) decoloratus, and tends to be more pathogenic, often manifesting as cerebral Babesiosis (the occurrence of nervous symptoms associated with parasitised erythrocytes).

3.    Babesia divergens and Babesia major

These protozoan parasites occur in more temperate climatic regions and share many common features with B. bovis and B. bigemina, respectively.

Babesia divergens is transmitted by Ixodes ricinus, whereas B. major is transmitted by Haemaphysalis punctata.

The disease is usually less severe in very young calves and in most cases develop only mild symptoms of disease or none at all.

In older animals, it often runs a more acute course and is characterised by obvious symptoms and high mortality rates in highly susceptible animals.

There is an age-related resistance in young calves due to the passive transfer of antibodies via the colostrum of immune cows to their calves, as well as a natural non-specific innate resistance which persists for a variable period after colostral immunity has declined and is independent of the immune status of the cow. Colostral immunity protects calves during approximately the first 2 months of their lives and the non-specific resistance for at least another 4 – 6 months.

In most animals, the disease is marked by:

• High fever (40 °C or more).
• Varying degrees of anaemia due to intravascular haemolysis (the rupture or destruction of red blood cells).
• The development of red urine (haemoglobinuria).

  

• Icterus (jaundice).
• In some instances, circulatory disturbances lead to organ damage, shock and death.

Other less specific symptoms include:

• Inappetence.
• Listlessness.
• Weakness.
• Constipation or diarrhoea.
• Abortion.
• Anorexia.
• Increased respiratory rate.

  

In some cases of Asiatic redwater (B. bovis), cerebral Babesiosis may develop, which is characterised by a variety of nervous signs such as:

• Hypersensitivity.
• Circling.
• Head pressing.
• Aggression.
• Muscle tremors.
• Poor coordination.
• Convulsions.
• Paralysis.
• The course of the disease is usually short and the outcome is almost always fatal.

In African redwater, (B. bigemina) acutely affected cattle are usually not as severely affected as those with Asiatic redwater, but the disease can develop very rapidly with sudden and severe anaemia, icterus and death. Signs of cerebral (brain) involvement are not seen and recovery in non-fatal cases is usually rapid and complete.

• Supportive treatment is advisable, particularly in valuable animals, and may include the use of anti-inflammatory drugs, corticosteroids, and fluid therapy. Blood transfusions may be lifesaving in very anaemic animals.

  

• Recovery is usually followed by a long-lasting immunity, which may last for life, even in the absence of re-infection.
• The main compounds used for the treatment of Babesiosis in cattle are diminazene and imidocarb. Both can be used prophylactically (i.e., guarding against or preventing the spread or occurrence of disease or infection) to protect animals against the development of clinical disease for a variable period after treatment.
• MSD Animal Health antiprotozoals:

Ø  Forray 65® Injection

Ø  Imizol®

• Vaccination.

(Particular attention should be paid to the residual effect of the beforementioned drugs should vaccination be considered as a long-term control option, as the inhibitory effect on the parasites in the redwater vaccines persists for considerably longer than against the naturally-transmitted parasites. Therefore, animals treated preventatively will again become susceptible to redwater for several weeks before they can successfully be vaccinated against the disease.)

• Tick control.

Bovine besnoitiosis (Elephant skin disease)

Besnoitiosis, caused by tissue cyst–forming apicomplexan parasites of the genus Besnoitia, is usually a chronic and debilitating disease characterised by skin lesions and systemic clinical signs of varying severity.

Bovine besnoitiosis is widely distributed in sub-Saharan countries. Cattle are the intermediate host for Besnoitia besnoiti, which occurs in Africa, Asia, Europe, and Venezuela.

In cattle, transmission occurs mainly through direct contact between infected and noninfected animals. Accordingly, parasite transmission may be favoured by natural breeding. Mechanical transmission of B. besnoiti was also achieved experimentally either with a syringe or with bloodsucking insects. The role of arthropods in parasite transmission is also supported by the seasonal incidence of the disease.

Bovine besnoitiosis progresses in two sequential phases:

1.    Febrile acute (anasarca) – may go undetected:

• Starts with a fever.
• Oedema. In severe cases, oedema in alveolar and interstitial tissues in the lungs, accompanied by pneumonitis (inflammation of lung tissue) and emphysema (a lung condition that causes shortness of breath), may also cause severe respiratory disorders.
• Swelling of superficial lymph nodes.
• Inappetence.
• Hyperemia (an increased amount of blood in the vessels of an organ or tissue in the body)of the skin.
• Orchitis (inflammation of one or both testicles).

  

• Lameness.

2.   Chronic (scleroderma):

• Tissue cysts – especially of the superficial layers of skin, mucous membranes of the upper respiratory tract, the vestibulum vaginae, and the testes and epididymis.
• Tissue cysts in the scleral conjunctiva are pathognomonic.

  

• Cutaneous lesions such as thickening and folding of the skin in the neck and the perineal region (also in the scrotal skin).

  

• Loss of necrotic epidermis.
• Atrophy (thinning or wasting away of tissue) and hardening of the testes of bulls.

Death may occur in both the acute and chronic stages of the disease. Severely affected bulls can become sterile during acute and chronic infection. Affected animals remain carriers for life.

• There are no effective treatments and no licensed vaccines for besnoitiosis.
• Selective culling of animals with clinical signs, as well as unproductive cattle, is recommended.

Biosecurity measures are key to controlling it:

• Risky practices (e.g., sharing pastures or bulls) should be avoided.
• The introduction of the disease by new infected entries should be prevented.
• Repellents and ectoparasiticides should be used both indoors and outdoors.

Coccidiosis

Coccidiosis is caused by single-celled parasites (not bacteria) known as coccidia. There are several species in cattle, not all of which cause disease. The species that cause disease are primarily found in the large intestine and diarrhoea results from damage to the cells lining it.

Coccidiosis is seen in animals up to 2 years old and is mainly common in calves between 3 weeks and 6 months of age.

Cattle become infected when placed in environments contaminated by older cattle or other infected calves. This can happen either indoors on bedding, or outdoors around drinking or feeding troughs. For the coccidial oocysts (the egg stage of the parasite) to become infective they require warmth and moisture.

Poor hygiene, high stocking density, poor health and poor nutrition will all contribute to a calf picking up the parasites and subsequent disease.

Symptoms are not always specific to coccidiosis.

• Diarrhoea (often very watery).
• Depression.
• Loss of appetite.
• Weight loss.
• Dysentery (passing blood-stained faeces).
• Death is rare.
• Infections that fail to produce diarrhoea can, nevertheless, result in reduced growth and weight gain. This sub-clinical infection is very common.

• Infected animals should be isolated as soon as possible to avoid exposing other cattle to infected manure.
• Most calves recover without treatment.
• Treatment is best for infected in-contact animals that have not yet started showing signs, or to combat secondary infection.
• Chemical groups that are effective against coccidia include triazine triones, ionophores, sulphonamides, diclazuril, and so forth.

A miscellaneous MSD Animal Health product for the treatment of coccidiosis in cattle:

Ø  VECOXAN®.

• To achieve effective control of coccidia, good management and hygiene are important.
• Young susceptible animals should be kept as clean and dry as possible.
• Feeding and watering equipment should be cleaned and protected from faecal contamination.
• Avoid feeding cattle on the ground, especially calves, so manure does not contaminate the feed.
• Excessive moisture in pens should be drained, and dry bedding should be provided.
• Use well-drained pastures, and avoid forcing animals to graze down to the roots of the plants so they do not eat large numbers of parasites.
• Try to keep grazing to a minimum in areas where cattle congregate (e.g., by water).
• In some areas, medication can be placed in the water or feed to prevent infection.

Cryptosporidiosis (Crypto)

Crypto is a highly prevalent gastrointestinal parasitic disease caused by protozoan species of the genus Cryptosporidium that infect a wide range of animals, including people, throughout the world.

C. parvum is a common cause of calf diarrhoea. Infection can be detected as early as 5 days of age, with the greatest proportion of calves excreting organisms between 9 – 14 days of age. Many reports associate infection in calves with diarrhoea occurring at 5 – 15 days of age.

Transmission may occur:

• Directly from calf to calf.
• Indirectly via fomite or human transmission, from contamination in the environment, or faecal contamination of the feed or water supply.

Cryptosporidiosis infections in domestic animals could spread to people who are more likely to get sick. C. parvum is a common non-viral cause of diarrhoea that goes away on its own in people with healthy immune systems, especially children. The clinical disease can be very severe for people who don’t have strong immune systems. Most of the time, the infection is spread from person to person. However, direct infection from animals and waterborne infection from surface water and drinking water that has been contaminated by faeces from domestic or wild animals can also be important. Animal handlers on a calf farm can be at high risk of diarrhoea due to cryptosporidiosis transmitted from infected calves.

• Calves with cryptosporidiosis usually have mild to moderate diarrhoea that persists for several days regardless of treatment. faeces are yellow or pale, watery, and contain mucus.

  

• Persistent diarrhoea may result in marked weight loss and emaciation.
• Varying degrees of apathy, anorexia, and dehydration are present.

• There is no affective or approved treatment for Crypto.
• Symptomatic treatment in the form of oral or parenteral fluid to counteract and prevent further dehydration and electrolyte replacement.
• Sick calves should be housed in a clean, warm, and dry environment.
• Nutritional support to give them the energy to fight disease and repair their bodies, and administration of antidiarrheal remedies.
• Cryptosporidiosis is difficult to control:
• Move unaffected calves to a clean area and away from affected calves to prevent the spread of disease on the farm.
• General sanitation practices are important.
• Efforts should always be made to ensure adequate colostrum intake by calves immediately after birth to help prevent invasion by opportunistic pathogens which can worsen or compound the severity of disease in calves with crypto.
• People who don’t have strong immune systems should be restricted from access to young animals and possibly from access to farms.

Neosporosis

A disease caused by an infection with the protozoa Neospora caninum. Neospora has been found worldwide and in many species other than cattle. The most observed problem in cattle is abortion, especially in intensively farmed cows.

Neosporosis in cattle herds manifests in both endemic and epidemic abortion patterns, but it is also possible for a herd to have a high infection prevalence without a noticeable abortion problem. Both endemic and epidemic transmission patterns in cattle are positively associated with the presence and number of dogs in and around farms. Dogs are definitive hosts of N caninum and are capable of shedding oocysts in faeces after eating the tissues of infected animals.

Endemic abortion is mainly associated with the recurrence of dormant organisms during pregnancy followed by transplacental transmission to the foetus, although occasional transmission from dogs or other canids may worsen the problem.

Epidemic abortion possibly results from a sudden large-scale transmission to pregnant cattle, presumably by ingestion of a mixed ration or water that has been contaminated with infected canine faeces.

• Abortion, between 3 – 9 months of pregnancy (particularly 5 – 7 months).
• Stillbirth or premature calf.
• Occasionally, calves will have brain disease at birth.
• No other signs are seen in the mother.
• Repeated abortions are possible in the same cow.

• There is no approved treatment for neosporosis in cattle.
• Currently, there are no available Neospora vaccines for cattle.
• Contamination of feedstuffs used in mixed rations by canine faeces should be avoided. Large dairies can consider erecting dog-proof fences around the area in which feedstuffs are stored outdoors, and automatic gates can be installed to facilitate the daily traffic of heavy machinery. Smaller dairy farms may be able to protect feedstuffs within traditional buildings such as barns, grain bins, and silos.
• Herds with endemic neosporosis abortions may consider not keeping heifer calves born to infected cows, thereby reducing the number of congenitally infected replacement heifers that enter the breeding herd.
• Deadstock, offal from home slaughter, and placentas should be discarded in a manner that prevents ingestion by dogs to reduce the risk that dogs will become infected and shed Neospora oocysts on the farm.

Theileriosis

Theileriosis refers to diseases caused by tick-borne protozoan parasites belonging to the genus Theileria. Some Theileria spp. Cause only mild or inapparent disease (benign Theileriosis), whereas others are highly pathogenic (malignant Theileriosis).

• Corridor (or Buffalo) disease:

A malignant Theileriosis of cattle usually results in death. It is caused by protozoa known as Theileria parva lawrencei. The ticks that can spread this disease to cattle in South Africa are the brown ear tick and the Lowveld brown ear tick, Rhipicephalus spp.

This disease occurs in the Limpopo Province, Mpumalanga, and KwaZulu-Natal in South Africa. It also occurs in Botswana, Zimbabwe, Mozambique, and Angola.

Buffalo are carriers of the disease. Cattle are infected when they are bitten by ticks that have fed on infected buffaloes. Therefore, the disease only occurs in cattle grazing pastures on which buffaloes are or have recently been present.

Buffaloes do not normally become sick when they are carrying the parasite or have these parasites on their bodies.

Not all buffaloes are infected.

The disease does not normally spread between cattle. Therefore, the disease does not continue spreading once cattle are removed from the buffaloes in the case of an outbreak.

• East Coast Fever:

A malignant Theileriosis of cattle caused by the protozoa, Theileria parva parva.

It is a serious problem in east and southern Africa.

Cattle are infected when they are bitten by infected vector ticks, Rhipicephalus appendiculatus, during feeding. Ticks acquire infection by feeding on infected cattle or African buffalo (Syncerus caffer), which carry the infection but do not show signs of disease. Both cattle- and buffalo-derived T parva are highly pathogenic when transmitted to cattle, but the latter does not develop to the piroplasm stage (i.e., infective stage) and therefore are usually not transmitted by ticks from infected cattle.

• Zimbabwe Theileriosis:

A malignant Theileriosis of cattle caused by the protozoa, Theileria parva bovis. It is an acute, frequently fatal disease of cattle that occurs in Zimbabwe. It has been variously known as January disease, because of its seasonal occurrence, and Fortuna disease, after the farm on which it was first recognised.

The disease resembles East Coast fever but the disease has a seasonal occurrence (during the period December to May) in Zimbabwe and the infections can be milder than in East Coast fever.

Transmission is principally by adults of Rhipicephalus appendiculatus.

• Fever (shown by depression, listlessness, standing apart).

  

• Enlarged glands (especially the ones below the ear and the ones in front of the shoulder and the knee).
• Decreased milk production.
• Loss of appetite.
• Watery discharge from eyes.
• The gums and mucous membranes of the eyes may be pale.
• Weakness.
• Difficulty in walking.
• Suppressed cough.
• Dyspnoea before death occurs.
• Frothy fluid coming from the nose just before death.

  

• May show nervous signs such as walking in circles and paralysis.
• Animals frequently die within 18 – 24 days after infection and death usually results from lung oedema.

• Because malignant Theileriosis has a very quick progression, treatment is usually not possible.
• Parvaquone, and more recently buparvaquone, have proven to be valuable therapeutic agents for the treatment of clinical Theileriosis. Treatment does not eliminate the parasite from the host and recovered animals usually remain carriers. In South Africa, the treatment of sick animals is illegal because treated animals may become carriers of the disease and infect ticks.
• When an outbreak occurs, the cattle are moved to uninfected pasture and strict tick control is introduced.
• Immunisation of cattle using the infection-and-treatment method is gaining acceptance in several endemic areas.
• Avoid buffalo contact with cattle, by movement control and fencing between cattle and game areas.
• Buffaloes can only be introduced into farming areas if they are free of infection (blood test).
• Stringent tick control through frequent dipping. However, this is not sustainable indefinitely.

Trichomoniasis

Trichomoniasis is a venereal disease of cattle caused by the protozoan Tritrichomonas foetus, which is found in the genital tracts of cattle. Therefore, when cows are bred naturally by an infected bull, they become infected.

Bulls of all ages can remain infected indefinitely, but this is less likely in younger males. By contrast, most cows are free of infection within 3 months after breeding. However, immunity is not long-lasting and reinfection does occur

Transmission can also occur when the semen from infected bulls is used for artificial insemination (AI). Before AI, this disease was as common in dairy cattle as Campylobacter-infection. Now, it is mostly seen in enhanced herds where infected bulls are used.

It has a worldwide distribution, especially in countries where natural service is commonly practised.

The symptoms are like those seen with a Campylobacter-infection and therefore the diagnosis must be confirmed by taking a sheath wash and/or scraping from all the bulls and sending it to the laboratory for microscopic examination.

• The most common signs include early foetal death and infertility caused by embryonic death, resulting in extended calving intervals.
• The cow fails to conceive from 3 or more regularly spaced services in the absence of detectable abnormalities.
• Farmers or farm workers will often note cows in heat when they should be pregnant.
• Poor pregnancy test results (e.g., too many “non-pregnant normal” and late-bred cows).
• An increased number of cows with a “non-pregnant abnormal” reproductive tract diagnosis is seen. These include cows with pyometra (a secondary infection that occurs because of hormonal changes in the female’s reproductive tract), endometritis (infection in the uterus), or a mummified foetus.
• Infected dams can give birth to live calves.

• Imidazoles have been used to treat bulls, but none are both safe and effective.
• Cull infected bulls as treatment or vaccination is not economically justifiable or efficient.
• Bulls should be tested annually. It is also advisable to test bulls before breeding.
• Heifers and cows can be vaccinated to reduce the level of infection. Initially, 2 vaccinations are given and then repeated annually. Infected cows may need to go through several heat cycles to become fertile again.
• Avoid buying non-pregnant cows, as they may be a source of the infection.
• Test all bulls when they are imported or change ownership. However, frequent bull testing will control the disease.
• Clean herds can be developed using young (“clean”) heifers and bulls, or AI can be used with semen that is certified.

Trypanosomiasis (Trypanosomosis)

A group of diseases caused by protozoa of the genus Trypanosoma.

Nagana (Tsetse disease):

Transmission is mainly by tsetse flies (Glossina spp.). Important causal organisms in cattle in southern Africa include Trypanosoma vivax, T. congolense, and T. brucei rhodesiense.

Most of the symptoms of Nagana are common to domestic animals, irrespective of the species of trypanosome involved.

Nagana:

• Intermittent fever.
• Anaemia.
• Severe loss of condition and emaciation.

  
  

• General weakness.
• Enlarged lymph nodes.
• Abortion.
• Decreased milk production.
• Lacrimation.
• Decreased fertility.

• Very few drugs are available to treat infected animals. The most used trypanocides (a drug or agent that is effective in killing trypanosomes) are diminazene aceturate, isometamidium chloride and homidium salts. Diminazene aceturate and homidium salts are curative compounds with little prophylactic action. Isometamidium chloride is most commonly used for prophylactic treatment.
• Prophylactic drugs can be used routinely or strategically during seasons of highest challenge.
• Treatment of infected animals is generally conducted using curative drugs. Unfortunately, resistance against both curative and prophylactic compounds is widespread.
• At present no vaccine is available.
• Nagana can be controlled by controlling the vector (tsetse fly) and/or the parasite.
• Eradicate the tsetse flies transmitting the disease. By spraying insecticide on the tsetse habitat, destroying the tsetse habitat and changing the vegetation so that it becomes unsuitable for tsetse flies.
• Unless tsetse flies can be eradicated, tsetse control measures must be sustained to prevent reinvasion of areas where the fly has been controlled.

Disulfox L.A.

• Cattle, Sheep and Goats: Treats footrot, pneumonia, navel ill, and joint ill.
• Horses: Treats pneumonia, strangles, navel ill, and joint ill.
• Pigs: Treats pneumonia and joint-ill.
• Calves and Lambs: Treats coccidiosis and bacterial scours.

Engemycin® 10%

• Cattle: Treats tick-borne gallsickness (anaplasmosis), heartwater, bacterial pneumonia, mastitis, bacterial enteritis, navel- or joint-ill, and bacterial wound infections.
• Horses: Treats strangles, bacterial pneumonia, and enteritis.
• Pigs: Treat bacterial pneumonia, mastitis, bacterial enteritis, navel- or joint-ill, and bacterial wound infections.
• Sheep and Goats: Treats heartwater, bacterial pneumonia, footrot, mastitis, navel- or joint-ill, and bacterial wound infections.

Engemycin® Spray

Treatment of topical infections such as lacerations, abrasions, gaping wounds, dermatitis and footrot in cattle, sheep, and swine, caused by or associated with organisms susceptible to oxytetracycline.

Reverin 135

For the treatment of heartwater, tick-borne gall sickness (anaplasmosis), pneumonia, navel ill, joint ill and footrot in stock and strangles in horses.

Long- and short-acting oxytetracycline injection.

Reverin LA 230

• Cattle: For the treatment of tick-borne gallsickness (anaplasmosis), heartwater, footrot, pneumonia, navel-ill and joint-ill.
• Pigs: For the treatment of pneumonia, footrot, joint-ill and navel-ill.
• Sheep and Goats: For the treatment of heartwater, pneumonia, joint-ill, footrot and navel-ill.

Anthravax®

For the active immunisation of cattle, sheep, and goats against anthrax.

Can be used during pregnancy and lactation.

Blanthrax®

Combined blackquarter-anthrax vaccine for the active immunisation of cattle, sheep, and goats against anthrax and blackquarter (Quarter Evil).

Can be used during pregnancy and lactation.

Botuthrax

For the active immunisation of healthy cattle, sheep, and goats against botulism and anthrax. Immunity is established within 3 – 4 weeks after inoculation and lasts for approximately 1 year.

Botuvax®

For the active immunisation of cattle, horses, sheep, and goats against botulism.

Bovi-Tect III

The combination vaccine is to be used in cattle. The vaccine reduces the incidence of morbidity and mortality caused by undifferentiated bovine respiratory diseases (pasteurellosis) associated with Maninheimia (Pasteurella) haemolytica, BHV 1 (infectious bovine rhinotracheitis – IBR) and BVDV 1. This vaccine is recommended for inclusion in a vaccination programme of feedlot cattle at processing.

Bovi-Tect P

Mannheimia (Pasteurella) haemolytica vaccine for cattle. The vaccine reduces the incidence of morbidity and mortality caused by undifferentiated bovine respiratory disease (pasteurellosis) associated with M. (Pasteurella) haemolytica. This vaccine is also recommended for inclusion in a vaccination programme for feedlot cattle at processing. For optimal use, consult your veterinarian.

Bovi-Tect PI

The combination vaccine is to be used in cattle. The vaccine reduces the incidence of morbidity and mortality caused by undifferentiated bovine respiratory diseases (pasteurellosis) associated with Maninheimia (Pasteurella) haemolytica and BHV 1 (infectious bovine rhinotracheitis – IBR). This vaccine is also recommended for inclusion in a vaccination programme of feedlot cattle at processing. For optimal use, consult your veterinarian.

Bovilis® C7 Somni

Indicated for the immunisation of healthy cattle as an aid in preventing diseases caused by Clostridium chauvoei, C. septicum, C. novyi type B, C. sordellii, C. perfringens type C and D, and Haemophilus somnus.

Bovilis® S

An aid in the control of cattle salmonellosis and calf paratyphoid caused by Salmonella dublin and S. typhimurium. After a natural challenge with Salmonella spp., vaccinated animals may develop the mild disease but do not shed the organisms.

Bovilis® Vista 5 L5 SQ

The combined product is for the vaccination of healthy cows and heifers before breeding to reduce abortion due to IBR and prevent foetal infection caused by BVD types 1 and 2. The respiratory duration of immunity is at least 182 days for IBR, 206 days for BVD Type 1, and 200 days for BVD Type 2.

In addition, the vaccine can be used as an aid in the:

• Prevention of disease caused by IBR, BVD (type 2) and BRSV.
• Control of disease caused by BVD (type 1) and PI₃.
• Preventing leptospirosis caused by Leptospira canicola, L. grippotyphosa, L. hardjo (including the L. borgpetersenii serovar hardjo bovis), L. icterohaemorrhagiae, and L. pomona.
• Prevention of urinary shedding of L. hardjo organisms.

Bovilis® Vista Once SQ

For the vaccination of healthy cattle, 3 months of age and older, as an aid in the prevention of respiratory disease caused by infectious bovine rhinotracheitis (IBR) virus, bovine virus diarrhoea (BVD) type 1 and 2 and bovine respiratory syncytial virus (BRSV); and as an aid in the control of disease caused by bovine virus diarrhoea (BVD) virus, parainfluenza 3 (PI3) virus, Mannheimia haemolytica and Pasteurella multocida. DOI: at least 365 days for IBR, BVD (type 1), and BVD (type 2).

Additionally, for the vaccination of healthy cows and heifers before breeding to aid in the prevention of foetal infection, including persistently infected calves, caused by BVD virus (types 1 and 2) and as an aid in the reduction of abortion due to IBR.  Reproductive DOI: at least 217 days for IBR and at least 206 days for BVD (types 1 and 2).

Covexin®10

Clostridial vaccine for sheep and cattle from 2 weeks of age to prevent mortality, lesions and clinical signs of disease caused by various Clostridium spp.

Duovax

Combined botulism and black quarter (Quarter Evil) vaccine for the active immunisation of cattle, sheep and goats against botulism and black quarter (Quarter Evil).

Lumpyvax®

For the prophylactic immunisation of cattle against lumpy skin disease.

Multiclos

A vaccine for the active immunisation of healthy cattle and sheep against blackleg, malignant oedema (gas gangrene), bacillary haemoglobinuria, black disease (infectious necrotic hepatitis), diarrhoea, haemorrhagic enterotoxaemia, and pulpy kidney disease.

Piliguard® Pinkeye-1 Trivalent

For use in healthy cattle to aid in the prevention of pinkeye associated with infection by Moraxella bovis strains expressing pili like those expressed by isolates referred to by MSD Animal Health as Strains EPP 63, FLA 64 and SAH 38.

Respiravax

An inactivated vaccine for the prophylactic immunisation of calves and pregnant cows as an aid in reducing or preventing bovine respiratory disease caused by Bovine Herpes Virus 1 (IBRV), Bovine Viral Diarrhoea Virus type 1 (BVDV), Parainfluenza Virus type 3 (PI₃V) and Mannheimia (Pasteurella) haemolytica.

Rotavec® Corona

For the active immunisation of pregnant cows and heifers to raise antibodies against E. coli adhesion F5 (K99) antigen, rotavirus, and coronavirus. While calves are fed colostrum from vaccinated cows during the first 2 – 4 weeks of life, these antibodies have been demonstrated to:

• Reduce the severity of diarrhoea caused by E. coli F5 (K99).
• Reduce the incidence of scours caused by rotavirus.
• Reduce the shedding of virus by calves infected with rotavirus or coronavirus.

Sponsvax®

For the immunisation of cattle, sheep, and goats against black quarter (quarter evil).

Supavax®

For the active immunisation of cattle and sheep against anthrax, botulism, and blackleg.

Berenil® R.T.U.

• Cures and prevents Redwater in cattle and cures biliary fever in dogs and horses.
• Prevents Asiatic (European) Redwater for 2 weeks and African Redwater for 4 weeks.
• Also effective against infections caused by Trypanosomas.

Forray 65® Injection

• Kills redwater (babesiosis) and tick-borne gall sickness (anaplasmosis) organisms in cattle.
• Prevents Asiatic redwater for up to 4 weeks and African redwater for up to 8 weeks in cattle. Forray 65® Injection is also indicated for the treatment of canine and equine babesiosis.

Imizol®

• Kills redwater (Babesiosis) and tick-borne gallsickness (Anaplasmosis) organisms in cattle.
• Prevents Asiatic redwater for up to 4 weeks and African redwater for up to 8 weeks in cattle.

VECOXAN®

Anticoccidial agent for the treatment of Coccidiosis in cattle, sheep, and goats.