Brucellosis is a bacterial infection affecting domestic animals such as cattle, camels, donkeys, goats and sheep. People can catch the disease from animals.

The disease occurs world wide and is also known to occur in all tropical countries. It is caused by four strains of the bacterium Brucella, in various livestock. Only one species Brucella abortus is of economic importance in cattle. Brucella melintensis and Brucella suis occasionally affect cattle that come in contact with small ruminants and pigs respectively. Brucella arbortus has worldwide distribution. Cattle of all ages and sex can be infected with B. abortus.

The disease is spread when aborting animals discharge B. abortus bacteria in the placenta, foetus and vaginal discharges to the ground where they can survive for several weeks. The cattle become infected when they ingest or inhale contaminated material with the pathogens. Humans are affected when they consume milk from infected cows. The disease can be transmitted to the unborn calf through the placenta by the infected dam. The disease has negative economic consequences to stockmen in both modern intensive dairy systems and as well as pastoral production systems.

Diagnosis. Abortions occurring after 6 months of pregnancy are indicative. However, blood samples should be taken for detailed laboratory analysis to confirm the disease. Blood samples should be taken for agglutination test. When abortion occurs, aborted fetuses should be taken intact in a sealed container to the laboratory for detailed examination. The fetuses should be handled carefully with gloves to avoid human infection.

Brucella infections are known to be persistent and hence treatment with antibiotic is not recommended. It is therefore not practical and not viable to make any treatment attempt.

Tuberculosis is a bacterial infection of domestic animals, mainly affecting cattle and man. It is caused by Mycobacterium bovis bacteria and is distributed world wide. The bacterium is transmitted when an infected animal excretes the organism in various discharges such as exhaled air, saliva, nasal discharges, faeces, urine and milk. The germs can survive outside the host for several weeks as long as they are not exposed to harsh climatic conditions like direct sunlight.

Housed animals become infected when they inhale the causative organism. Grazing animals are infected through ingestion of the organism through feed supplementation and water troughs while calves may be infected by drinking milk from infected cows. Human beings are very susceptible to Mycobacterium bovis and Mycobacterium tuberculosis and they become affected by consuming un-pasteurized milk. The course of the disease is always chronic and usually lasts several months during which affected animals lose condition and may eventually die.

The infection causes an abscess in the lung as the first point of entry through inhalation of the causative organism. The infection then spreads to other organs and draining lymph nodes. Where infection is due to ingestion of the germs, the initial lesions would appear in the lymph nodes in the throat or intestines. As the disease advances, lesions in the lungs would cause persistent coughs stimulated by exercise.
Lymph nodes in the head, neck and fore quarters further become enlarged. The animal develops labored breathing and discharges yellowish secretion from the nose. The animal would also develop undulating fever through out the disease. Some times, the infection of the udder occurs thereby causing hard, nodular mastitis. There would be a general loss of body condition.

Enlargement of peripheral lymph nodes are indicative of the infection but not conclusive. In tuberculous mastitis the signs often involved inflammation often found at the base of the quarter of the udder with painless swellings where as in tuberculous Metritis the signs include yellow colored pus. Accurate diagnosis of tuberculosis requires the application of tuberculin test.

Because of the zoonotic nature of the disease, a lot of efforts have been put on strict control and eradication of the disease. Control measures depend on test of all animals for the disease using the tuberculin skin test. This test requires skilled man power to execute. Where animals are confirmed with the disease, infected animals can be removed and premises cleaned and disinfected. However, this exercise requires sound infrastructure and financial support to compensate farmers whose cattle are removed for slaughter.

Advancements have been made on treatment of human tuberculosis which can be applied for treatment of cattle. However, treatment of cattle is contra indicative and as such emphasis is put on prevention and control.

This is an infectious disease of cattle and goats which affects the lungs. In cattle it is called "Contagious Bovine Pleuropneumonia" (or CBPP) and in goats "Contagious Caprine Pleuropneumonia" (or CCPP).

Contagious Bovine Pleuropneumonia is caused by the bacterium Mycoplasma mycoides subspecies mycoides. The disease is widespread in Africa, especially in the semi-arid countries lying south of the Sahara from West Africa to Somalia. It also occurs in India, China, and South East Asia. Although nowadays mostly confined to the tropics, it is not primarily a tropical disease. In the past it was widespread in Europe, America, Australia and South Afrca before being eradicated. In cattle the disease can be acute, subacute or chronic and is characterised by by pneumonia, serofibrinous pleurisy and oedema of the interlobular septae of the lungs.

Contagious Caprine Pleuropneumonia of goats is caused by Mycoplama mycoides biotype F38 and closely resembles the disease in cattle but is more widespread in Kenya than CBPP. This disease is specific to goats and does not affect sheep, even when goats and sheep are in close contact. It also is a peracute, acute or chronic highly contagious disease characterised by a fibrinous pneumonia, pleurisy and a profuse pleural exudate.

The disease is transmitted between animals by coughing and the inhalation of droplets expelled by infected animals. The causative agent does not survive for long in the open environment hence direct contact is essential for transmission. The incubation period varies but in cattle most cases occur 3 - 8 weeks after exposure.

Infection spreads faster where the animals are crowded together e.g. in houses, stables, night bomas, markets and during transportation. A serious aspect of the disease in cattle is the carrier animal, commonly referred to as a "lunger", which appears clinically normal but has a localised focus of infection in its lungs. This focus is surrounded by fibrous tissue, walling it off from the rest of the lung. It may vary in size from the size of a pea to a large orange, but in time, perhaps after many months, the capsule may break down, allowing the still viable bacteria to escape through the bronchi and infect susceptible in-contact animals.The apparently healthy carrier animal therefore, is mainly responsible for the perpetuation of the disease.

"Lungers' do not occur in goats as they do in cattle."
The incubation period is rather less for the disease in goats than in cattle, being of the order of 3 - 5 weeks. The disease in goats is extremely contagious, affecting 100% of goats in a flock and killing 60 - 100% of them.

The disease in cattle is less dramatic, with lower numbers of a herd affected, sometimes only 10% , although this may rise to 50% with a death rate ranging from 10% to 50% of those infected. Of recovered animals 25% may become carriers with walled - off lung lesions, which cannot tbe detected.

In Kenya the disease in goats is much more common than that in cattle. In goats diagnosis should not be dificult. The characteristic signs of severe nasal catarrh, respiratory distress, coughing, rapid spread through the flock, the possible recent introduction of goats from another area, the non-transmission to sheep, coupled with the unmistakable post mortem findings should leave no doubt. If there is any doubt samples should be taken for laboratory analysis.

Contagious Bovine Pleuropmeumonia occurs less frequently, most often in cattle from the north, which may then transmit to susceptible cattle further south. Cases in live animals may be difficult to diagnose, being confused with diseases such as ECF,but a post mortem examination should point the way. Samples of lung should be forwarded for laboratory examination and serum samples taken from in-contact animals.

Goats may be treated, either with Tylosin Tartrate at a dose rate of 10mg/kg for 3 days or with Oxytetracycline at 15 mg/kg daily.

Treatment of cattle is not justified due to the risk of converting active infection into a carrier state and perpetuating the disease.

Contagious Bovine Pleuropneumonia is a Notifiable Disease imposing a strict quarantine on any affected farm, outwith an endemic area. Animals will be tested and affected animals will be slaughtered. Quarantine may continue for up to 3 - 4 months after the last clinial case or reactor. Vaccination will not be allowed in non-endemic areas due to the risk of spreading the disease via the attenuated vaccine.

Veterinary assistance should promptly be sought in the control of both of these diseases.

Common traditional practices (Source: ITDG and IIRR, 1996):

Water holes used by different species of animals are known to be another source of infection. Tissues of infected animals may be moved by rats and carrion eaters and transfer infection.

Humans are fairly resistant and are infected after an occupational hazard affecting workers in tanneries. The workers may as well inhale spores and suffer an acute fatal pneumonic form of anthrax. Cutaneous anthrax is common among people who carry meat and other animal products from infected carcass.

Following incubation of 1 - 2 weeks, the disease may manifest in very severe, severe and less severe forms.

• In very severe form, there is a short illness and this makes the disease difficult to treat. The animal develops high fever, difficult breathing followed by convulsion, collapse and death.
• In severe form, the disease would last about 2 - 3 days before death. The animal will appear depressed, listless and have high fever. The mucus membranes in the eyes and gums are congested and hemorrhagic. There is difficulty in breathing caused by edematous swelling in the throat.
• In less severe cases, some animals may survive for 1 week and others will recover.

In both severe and less severe cases, affected cows may abort and have a reduction in milk production. The milk will be blood stained or appear yellowish in color. Infection in the alimentary tract may cause dysentery.

It is highly risky to take samples of the disease by unqualified laboratory personnel. In all cases where anthrax is suspected, a strip of tape or cloth soaked in blood from a cut superficial vein, dried and placed in an air tight container together with blood smear samples are adequate. The sampling procedure should be carried out by qualified laboratory personnel.

Prevention and control require a strict adherence to veterinary regulations to prevent and minimize the spread of the disease among livestock and human.

Rabies is an acute viral encephalomyelitis-inflammation of the central nervous system, affecting all warm blooded animals including man. It is transmitted via the saliva of an infected animal, usually through the bite of a rabid animal. Once clinical signs appear it is almost invariably fatal. Rabid animals usually excrete the virus in their saliva 2 days before they show clinical signs and then throughout the course of the disease which is normally less than 10 days. On rare occasions dogs in Africa have been known to survive Rabies and to excrete the virus in their saliva for months.

Transmission usually occurs when infected saliva is deposited in a bite wound but less common routes of tranmission include inhalation of infected droplets in bat infested caves and by the ingestion of an infected carrier. In Kenya the dog is the main transmitter of Rabies.

The disease is of serious concern as the majority of dogs in the country are unvaccinated. It is common in both rural and urban areas. Many people are unaware of the mortal dangers associated with this terrible disease. Many people in rural areas keep dogs both as pets and for security. Because most rural people are not aware of: the hazards of the disease, they have not had their dogs vaccinated. As a result lives are put at risk for the sake of simple education and a few shillings.

Rabies virus deposited in a bite wound penetrates striated muscle cells where it either multiplies or becomes sequestered as a subviral particle. Within a few hours newly formed viral particles enter the peripheral nervous system and travel along the nerve trunks to the spinal cord and brain. From the brain the virus travels along peripheral nerves to the salivary glands. If an animal is capable of transmitting Rabies via its saliva,virus will be detectable in the brain.

The incubation period is both prolonged and variable. Bites close to the head result in symptoms appearing sooner than in an animal bitten, for example, on a lower hind limb. Sequestration of the virus in the area of the bite is believed to explain the occasional very long incubation periods recorded. Bites in areas with a rich blood supply are especially dangerous. In most clinical cases of Rabies the incubation period is of the order of 3 to 12 weeks, with occasional cases of periods of up to a year.

The dog is regarded as the main transmitter of the disease in Kenya. Cats and wild animals, such as jackals, can also play a part in transmission. Ruminants such as cattle, sheep and goats play little part in direct transmission but their role as indirest transmitters can be important.

The course of the clinical disease ranges from 2 to 10 days. There are three clinical phases: prodromal, excitative and paralytic. If the excitative phase dominates one refers to "Furious" Rabies. If the paralytic phase dominates one refers to "Dumb" Rabies.

The prodromal phase is manifested by a change in behaviour- friendly dogs become aggressive, fierce dogs become friendly. Affected cattle stray away from the herd. In dogs this phase may last for 2 - 3 days; in cattle a few hours.

In the excitative phase animals appear to be hypersensitive, restless, and may bite or attack without warning. Dogs often have a peculiar staring expression. They often drool saliva. The conjunctiva often is red and inflamed. They may attack any moving object and break their teeth and eat stones and sticks. Cattle may stare intently at people before charging them. They may break their way through fences. Donkeys may mutilate themselves biting and chewing their bodies to such an extent they occasionally even disembowel themselves. Cats become very aggressive, attacking withut provocation.

In the paralytic phase cattle may walk unsteadily, strain unproductively as though trying to pass dung, due to decreased sensation of the hindquarters, and bellow hoarsely, continuously, sometimes for hours on end. They drool saliva. They are unable to eat or drink. Dogs often have paralysis of the lower jaw, with a dry,darkened tongue.

Finally the animal becomes proressively paralysed,cannot eat or drink and dies. The period from the onset of symptoms to death is generally of the order of a few days, usually 3 to 4 days. Occasionally a rabid animal may show no obvious clinical symptoms and may die after a short undramatic illness.

Any animal behaving strangely should be suspected of having Rabies. The absence of a bite wound is immaterial as these, if they had been present, will have have healed long before the advent of symptoms.

Animals acting oddly should not be approached closely. Do NOT put hands into any animal's mouth searching for suspected non-existent foreign bodies. If saliva gets onto the hands they should be immediately washed vigorously with soap and disinfectant. Medical advice should be sought if there is ANY suspicion that an animal might have Rabies and a veterinary surgeon sought to examine the affected animal.

Animals suspected of having Rabies should be isolated, confined and otherwise kept enclosed and out of touch of people and other animals, until such time as the animal is either dead or alive at the end of 10 days. If the animal is still alive after 10 days one can confidently assume that it did not have Rabies.

In the case of dogs and cats the head will be examined at Kabete, brain tissue being tested using the Direct Immunofluorescent Test. The result should be available after a day. With cattle the size of the head and the difficulties of tranporting such a cumbersome mass to Kabete make this a matter harder to resolve. But do NOT attempt to remove the head youself. This is a job for a trained veternarinarian only! A laboratory diagnosis is important but in the absence of this if the symptoms suggest Rabies it is better to assume that that is what it is, rather than to do nothing and wait for the next case.