Livestock Disease Trends – April 2014

Due to late rains that fell in many parts of the country infestations of roundworm and especially wireworm were widespread, leading to production losses and mortalities. Lambs were the most susceptible.

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Roundworms: More and more reports of parasites resistant to various anthelmintic groups are being received. Farmers should ask their vet to assist them in doing tests to assess which drug groups are to be used for parasite control.

Tapeworms: Lambs were again the most vulnerable class affected. These parasites could also be resistant to certain anthelmintic groups.

Flukes: Animals will most probably be put to grazing in vleis during winter. The intermediate hosts (snails) will concentrate at these water sources and outbreaks of liver fluke and conical fluke will occur. Contact your local vet for a preventative control programme before animals are put into vleis for grazing.

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External parasites
Blue ticks: Numerous reports were received of African and Asiatic red water, anaplasmosis and lumpy skin disease. It is imperative that preventative measures are in place to control these parasites and diseases.

Bont-legged ticks: Caused foot abscesses and sores, and bacterial infections entering the wounds resulted in sitting disease. Cases of sweating sickness were also reported. The ticks attach in the tail switch where they are difficult to see.

Bont ticks: These transmit heartwater and reports of this deadly disease were received. With their long mouthparts causing wounds, bacteria enter, leading to abscesses.

Tick paralysis: Karoo paralysis ticks are causing problems after cold spells.

Other external parasites that caused problems were flies (opthalmia), biting flies (anaplasmosis, lumpy skin disease), blow flies (fly strike, wool loss), screw worm (sores and abscesses), tstetse flies (nagana), midges (blue tongue, African Horse sickness) and mites (sheep scab, mange, wool loss).

Veneral diseases
Biosecurity measures should remain in place to prevent trichomonosis and vibriosis, which cause huge economic losses. Discuss the testing of the herd for these diseases with your vet.

Bovine Brucellosis
To control and eradicate this zoonotic disease needs an immense effort from all role players – state veterinary services, private vets, farmers, farm workers, farmer and breeder associations, auctioneers and so forth.

Bacterial diseases

E. coli, salmonellosis, Corynebacterium, clostridial diseases such as blackquarter, swelled head, red gut, blood gut, botulism, tetanus, pasteurellosis, enzootic abortion, opthalmia, mastitis were reported.

Viral diseases
A few cases of IBR, BVD, enzootic bovine leucosis, warts and orf were reported.

The following were reported: Cardiac glycoside poisoning (witstorm, vaalstorm, tulip, slangkop), Cestrum, Cynanchum poisoning, facial exzema, geeldikkop/dikoor, kikuyu, Lantana, prussic acid, seneciosis, vermeersiekte, water contamination, urea, blue green algae and snake bite.

Feedlot report

Sheep feedlots

  • The wet weather and wet kraals led to numerous mortalities, with mostly the weaker and lighter lambs affected.
  • Groups of lambs heavily infested with wireworm had the biggest problems with adaptation. 
  • Cases of foot rot, foot abscess and blue tongue were seen, as well as a few cases of pulpy kidney.
  • Salmonella infections occurred again, with lambs having diarrhoea and eventually dying. Such lambs usually arrive at feedlots with diarrhoea or start with diarrhoea soon after arrival. This disease is probably induced due to the stress of transport and handling. The infection probably occurred on the farm of origin.

Cattle feedlots

  • Newly weaned calves and calves bought at auctions succumbed to pneumonia.
  • Anaplasmosis occurred and a few cases of red water were seen. Tick larvae were hidden in the long hair of the calves and were only seen if the hair coat was carefully scrutinized. Every year problems with ticks are seen till deep in winter. Anaplasmosis can occur at any time when periods of stress such as poor weather, nutritional problems and handling of animals take place.
  • Losses occurred where problems with feeding management occurred. Acidosis with cases of reed gut, bloat and vitamin B1 deficiency contributed to losses. Abscesses in the liver are a direct result of acidosis and damage of the rumen wall.
  • Calves with abscesses under the tail usually arrive from areas where bont-legged ticks and bont ticks are prevalent. Sitting disease is seen sporadically when the infection spreads to the spinal column. Such animals do not recover and have to be euthanized. 
  • Abscesses in the neck are due to infected needles and syringes.
  • Many animals with ringworm were seen. 
  • Measles are still a problem in cattle arriving from communal areas. However more and more cases are seen in cattle that were probably infected due to drinking water from polluted rivers. A carcass infected with measles means a loss of about a R1 000.

View the disease map to track outbreaks in your area.