Managing sudden death cow diseases

Cows in Eldoret during a trade fair on September 25, last year. Farmers need to watch out for deadly diseases file | NATION

What you need to know:

  • Many livestock farmers undergo untold suffering when their cows suddenly fall sick and they cannot reach a veterinary officer.
  • The pathogens come from the blood of infected animals and live long in the soil, and spread especially during the wet season. Some animals, especially camels, get infected on the skin when they are bitten by flies that carry the anthrax bacteria.
  • The carcass of animals that die of anthrax are very dangerous to people and other animals
  • When burning, the best thing to do is by digging a hole (about one metre long and nearly half a metre deep for a large animal) and placing dry grass, wood, or some old tyres in it. Add diesel or kerosene for complete burning.

Many livestock farmers undergo untold suffering when their cows suddenly fall sick and they cannot reach a veterinary officer.
In most cases, these diseases lead to sudden death heaping misery on farmers.

It is, therefore, important for farmers to understand conditions and diseases that lead to sudden death in animals to minimise losses.
Below are the common conditions and diseases that cause sudden death in livestock and how to handle emergencies in the unlikely absence of a vet:

a) Anthrax

Cows, sheep and goats are regularly affected by this disease, same as camels, dogs, horses, donkeys and pigs. This disease can also affect people, usually with fatal consequences. Normally, an animal falls ill 12-24 hours after getting infected. However, ruminants often die before the farmer can see any signs of the disease. Always suspect anthrax when an animal dies suddenly.

Causes of anthrax

Animals normally get infected when they graze in places where soils are infected with the anthrax microbes.

The pathogens come from the blood of infected animals and live long in the soil, and spread especially during the wet season. Some animals, especially camels, get infected on the skin when they are bitten by flies that carry the anthrax bacteria.

Signs

Affected animals may have blood in the urine, faeces or milk.

They often have difficulty in breathing and usually collapse and die after one to three days.

Most animals also exhibit high fever.

The animal also has a swelling under the jaw and sometimes under the neck, chest and abdomen. Some have sores and swellings on the skin.

When the animal dies, the classic sign is dark blood oozing from the nose, mouth and anus. This blood does not clot and the body does not go stiff.

Treatment

Most farmers do not usually detect the disease in their animals early, but if you do,
Give a long-acting antibiotic treatment, including Oxytetracycline for seven to 10 days. It works well if you give large doses soon enough.

When some animals in a group die of anthrax, watch the others carefully for about two weeks.

Take their temperatures and immediately treat any animals that have a fever.

Vaccine for anthrax is effective and lasts for nearly a year. County governments normally organise for the exercise every year in areas where the disease is a menace. Vaccinate animals a month before they go to an area where the infection is common.

Dealing with the carcass

The carcass of animals that die of anthrax are very dangerous to people and other animals. It is suicidal to consume meat from an animal with anthrax.

Blood from the carcass is also very infectious.

When anthrax microbes in the blood are exposed to air, they develop a thick protective wall. These thick-walled microbes are called spores, and can live for many years on the ground.

It is always prudent to notify a nearby vet in case you suspect an animal has the disease. However, it is safest to bury the body if you can in a deep pit (at least 6 feet deep) far away way from water that people and animals drink.

Burn or bury everything, including the soil that has come into contact with blood from the dead animal. Place some thorns or a fence to keep animals off the site.

When burning, the best thing to do is by digging a hole (about one metre long and nearly half a metre deep for a large animal) and placing dry grass, wood, or some old tyres in it. Add diesel or kerosene for complete burning.

b) Blackquarter/Blackleg
Cows and sheep, including healthy, well-fed, young animals, get black quarter often whereas other livestock species contract it occasionally. Animals become sick one to seven days after they get infected.

Symptoms

The disease is characterised by lameness, with the back legs becoming swollen and hot.

One can feel bubbles under the skin of the animal, which normally is unusually dry.

The wounds where the infection gets in are usually too small to see, and the attack happens quickly. A good number of animals often die before you can observe any signs of disease.

Infected animals appear tired and weak.

The animals have a high fever and mostly die after a day or two.

Causes of black quarter

Animals get infected through small wounds such as thorn pricks. The infection comes from the soil, where black quarter microbes live for long. Like anthrax, black quarter is also caused by bacteria.

Treatment

Treatment only works if it starts faster.

Give antibiotics (penicillin) although even with large doses, the drugs may not always be effective.

Some farmers treat black quarter by cutting into the muscle to let air in where the microbes are. Black quarter microbes cannot live in air, thus, they are killed. But this does not always work since the situation may be worsened by secondary infections.

Prevention and control

Vaccination for black quarter is effective and lasts for a year. Vaccinate animals every year in areas where this disease is a problem.

When an animal dies, burn or bury the body together with anything that has come into contact with it, as you would for anthrax.

c) Enterotoxaemia/Pulpy kidney

Sheep and goats contract enterotoxaemia, but the disease is most severe in the former.

How animals get infected

Animals get the disease when they suddenly eat much better fodder such as that at the start of a wet season when they go to new pasture or when they start eating grains. Usually animals aged a month to a year get it after they are weaned. Infection comes from the soil.

The microbes grow quickly in the intestines and produce strong poisons that make the animal sick. Enterotoxaemia is caused by bacteria (Clostridium perfringens – TypeD).

Many animals, however, die before they have shown signs of the disease.

Signs

The disease is characterised by the animal bending its head back.

Infected animals also become restless, suddenly weak and tired.

They throw their heads backwards and stretch their legs out.

They soon have convulsions and often die in an hour.

Normally, the intestines of the dead animal are dark red, the kidneys are soft, the sac around the heart has blood-stained fluid in it and the abdomen also has blood-stained fluid in it.

Treatment

There is no effective treatment for an animal that already has severe form of this disease. However, if suspected early, then switch the herd to poorer feed immediately. Thereafter, better quality fodder can be introduced gradually. It may help to give antibiotics to other animals in the group before they become sick.

Prevention and control

Avoid suddenly moving sheep or goats to a much better pasture or providing a lot of high quality supplements (such as concentrates).

Vaccination for enterotoxaemia is effective. Vaccinate pregnant animals a month or two before they give birth to protect the calf. Vaccinate young animals when they are two months old. Give two doses three weeks apart. Vaccinate again every six months.

d) Other causes of death

Animals hit by lightning usually die on the spot. Such animals may have tell-tale burns on the skin but the burns are not always easy to see and one may have to look carefully under the hair to find them. Other less common causes of sudden death may include poisoning (especially cyanide poisoning), severe worms, accidents and injuries, navel ill, snake bites, choking and acute bloat.

The writer is based at the Department of Animal Sciences, Egerton University.