3 Important Diseases in Sheep

BLUETONGUE

Bluetongue, also called bloutong, is more important in sheep. This disease is non-contagious, but is spread by small biting insects (midgets), and is therefore more common in late summer and autumn and can be prevented by vaccination.

It is believed that the virus somehow survives in overwintering midges or animals. Twenty-four serotypes are now recognised in South Africa for this virus, hence the live vaccine divided in three fractions viz. A, B and C, each with a 3-week interval injection. Animals are not to be vaccinated after 8 weeks prior to breeding season, and pregnant ewes are not to be vaccinated at all, because of the fever that is caused by the vaccine.  However, if an emergency occur, ewes can be vaccinated in the last half of pregnancy, with risk.  Lambs younger than five months are also not to be vaccinated.

Treatment involves nursing:

When outbreaks occur, move animals away from wet areas with standing water where midges flourish.

Animals with Bluetongue, have sore muscles and fever, are light sensitive, and are dehydrated. Bluetongue is very similar to flu in people.  The fever reaction cause abortions and a break in the wool.

The sheep 's mouth and tongue hurts, and therefore it is to painful for the animal to eat. However, sores in the mouth and a "blue" tongue isn’t always present. Animals do not want to walk because their feet are sore. Sick animals often get secondary pneumonia that can cause death. Well-kept bluetongue cases usually survive.

The treatment of Bluetongue infection is as follows (in order of importance):

• Set dehydration right.  Animals can’t walk far to drink water if it’s very hot, they dehydrate quickly.
• Give lambs 1 to 2 liters of glucose and salt solution that is available from your veterinarian or cooperation. Give adult sheep to 5 liters.
• If nothing else is available, give a heaped teaspoon of salt and a tablespoon of sugar accumulated in two liters of water.
• Rinse mouth and nose with a strong solution of salt, Animals will not eat with sore mouths and blocked noses. Salt is a good disinfectant for the mouth. Mix a tablespoon of salt in a cup of water and use as a spray in the nose and mouth. Remove crusts in nostril with a cloth, cotton wool or toilet paper.
• Put sick animals in a stable. Under a tree, in a camp is not good enough. Sick sheep will often lie in the sun themselves. Nights may be cool and days warm.  A stable or shed is much better for sick animals. Give straw to sleep on or slats. Provide food and water and dose water if they are not drinking by themselves. Control pesky flies and mosquitoes.
• Give lucerne after 24 hours. Sheep that is not eating will not recover easily. Take fresh lucerne or grass and mash it in a domestic foodprocessor together with water. Pour it through a sift and dose the sheep with it.
• Treat with antibiotics and anti- inflammatory agent. Sick sheep's fever has not diminished with Disprin. Antibiotics or sulfa pills contributes to the death of the microorganisms in the rumen. Long-acting tetracycline’s make muscles painful and increase sensitivity of light. Antibiotics doesn’t make the bluetongue virus dead, but prevent pneumonia. Use a drug that is effective against Pasteurella - talk to your veterinarian about the selection or use of an injectable sulfa agent eg. Disulfox LA (G3441)
• Get injectable anti-inflammatory drug to your veterinarian for pain and fever. (Predef)

The information contained herein is intended only as general guidelines – you should always consult your veterinarian for advice.

PULPY KIDNEY

Pulpy kidney is one of the major diseases which the farmer should have knowledge about. The signs seen are usually sudden death and there is usually no time to treat the animals. Sheep die due to toxins released by the overgrowth of Clostridium perfringens type D bacteria normally found in the intestines of sheep. Such overgrowth occurs when sudden changes occur in the diet of the animals and especially accelerate the flow of the intestinal content.  One of the names for pulpy kidney is "overeating disease”. (moving sheep to more / better food).

It can also happen when animals, with a heavy precipitation of intestinal parasites are de-wormed. The best prevention is vaccination. Vaccinate animals AT LEAST two times per year.

The information contained herein is intended only as general guidelines – you should always consult your veterinarian for advice

WIREWORM

There are many types of worms that can affect sheep, but the most important type is wireworms. The signs seen are often bottlejaw and paleness of the mucous membrane and gums because of the adult worm that cause anemia. Sometimes diarrhea is also noted. Weight loss, loss of appetite and death can occur.
The Famacha© method of selective treatment was developed by three South African researchers (Doctors Faffa Malan, Gareth Bath and Jan van Wyk) as a possible solution for the large anthelmintic resistance problem in South Africa. Since then, the method was successfully implemented worldwide.
The main purpose of the method is to sufficiently maintain susceptible wireworm population (`refugia’) on the pasture. By deworming only those sheep that really needs to be dewormed, resistance to anthelmintics can be delayed. At the same time the farmer monitors the animals and cull those with poor naturally resistant to these worms.

Anemia (as observed in the mucous membrane) can be seen with the help of a color guided card:  sheep with a score of 1 has a pink - red mucous membrane color and do not need treatment for wireworm, while those with a score of five has a white mucous membrane and must be dosed immediately against wireworm and probably must be given intensive medical treatment.

The information contained herein is intended only as general guidelines – you should always consult your veterinarian for advice.

The FAMACHA-chart is available from your local veterinarian who can order it from me. Lana Botha at the Faculty Veterinary Sciences, University of Pretoria. (lana.botha@up.ac.za)