Case reports from veterinary officers

Barber's pole worm loves warm weather

Paul Beltz, Senior Veterinary Officer – Agriculture Victoria

Barber's pole worm (Haemonchus contortus) has been identified as the cause of sheep deaths in the south-west of Victoria following warm weather and thunderstorms in November and December 2018. This blood sucking stomach parasite thrives in warm, moist conditions where it can build up very quickly and result in the death of affected animals. Barber's pole worm is present on farms across Victoria but rarely causes disease as the climate does not normally favour it reproducing rapidly.

The female Barber's pole worm lays large numbers of eggs, so a rapid population explosion is likely when weather conditions favour it, such as the conditions we have experienced recently.

Sheep producers now checking their stock for flies should also be aware of the symptoms of a Barber's pole worm infestation.

Affected sheep will be weak and have very pale eyelids and gums. This worm does not cause scouring and affected sheep will have firm pellets. In some instances, the first sign may be sheep dying.

A faecal egg count or necropsy can confirm diagnosis. Fortunately, in Victoria most drenches should control the disease.

Read more about Barber's pole worm.

Theileriosis in Angus cattle

Jeff Cave, District Veterinary Officer – Agriculture Victoria and the Veterinarians at Walwa Veterinary Clinic

Thirteen of 100 adult home-bred Angus cows died and more than 40 head were clinically affected by theileriosis on a property in the Upper Murray of north-east Victoria in November 2018. Clinically affected cattle initially displayed pyrexia before becoming pale and icteric (jaundiced). Necropsy of two cows revealed icterus and splenomegaly. Intra-erythrocytic tennis racquet inclusions consistent with Theileria spp were seen in stained blood smears from affected animals.

Since becoming endemic in 2010, theileriosis is not an unusual disease in north-east Victoria. However, the scale of this outbreak was abnormal.

There are a number of factors that may have contributed to the size of this outbreak:

• inherent poor health of this herd, which resulted in reduced immunity
• a lack of recent exposure to Theileria spp
• the recent exposure to very high numbers of Theileria spp because of favourable environmental conditions for its intermediate host.

Ongoing work is being carried out to ascertain whether a novel strain of theileria was involved. The producer was presented with several recommendations, such as improving overall herd health and controlling potential exposure to theileria through avoiding heavily vegetated, wildlife rich paddocks after periods of warm rain.