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Looking out for Theileria

Cattle TickNorth Coast Local Land Services District Veterinarians are reminding North Coast cattle producers of the risks associated with introducing cattle from outside the region following recent cases of bovine anaemia caused by Theileria oreintalis group.

Theileria are protozoan parasites that can be carried by ticks. The bush tick, which is widespread on the North Coast, is known to carry this protozoal parasite.

When ticks feed on cattle the parasite enters the red blood cells and these cells are destroyed. If large numbers of red cells are destroyed the ability of blood to carry oxygen is reduced and the animal may become ill. Clinical signs include weakness and lethargy, exercise intolerance, drop in milk production, pale and/or yellow membranes and abortion or stillbirths in pregnant cows and death.

Local cattle generally develop immunity to the parasite early in life, although clinical cases may be seen in a small number of young calves around 2-3 months of age.

Ian Poe, District Veterinarian said, “We also see cases in adult cattle introduced into the region from areas where the parasite is not present, such as inland or southern districts.

In the case of introduced cattle, disease is mostly seen about 5-12 weeks after introduction. Heavily pregnant cows and heifers are often most severely affected and introduction of these classes should be avoided.

Ian continued, “Current treatment options for cattle that are affected with Theileria are limited and responses to treatment are often poor especially in severely affected animals.

“Stress and movement of affected animals should be minimised and when movement of affected mobs is necessary it should be done slowly.”

For further information contact the North Coast Local Land Services District Veterinarian team or a private veterinarian.

Media contact:

Ian Poe, District Veterinarian Phone: 0429 987 255

Photo captions:

The bush tick that can carry the Theileria parasite

Image Credit:  ABC