Consider Theileria Risk When Introducing Cattle into your Herd
18 Nov 2020
North Coast Local Land Services District Vets are reminding cattle producers of the risks associated with introducing cattle from outside the area following recent cases of bovine anaemia caused by the Theileria oreintalis group.
Theileria are protozoal parasites that can be carried by ticks. The disease is endemic to the North Coast. The bush tick, which is widespread in the north coast LLS region, is thought to be the primary vector responsible for spreading the parasite.
District Veterinarian Jocelyn Todd says, ‘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 of Theileria include weakness and lethargy (lack of willingness to walk), difficulty breathing (gasping if forced to run), reduced milk production, Jaundice (yellowing/pale gums) and abortion or stillbirths in pregnant cows.
‘As these signs are often symptomatic of many other conditions, it is important to confirm diagnosis via a blood sample taken by a veterinarian’ said, Jocelyn.
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. 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 6 - 12 weeks after introduction. Heavily pregnant cows and heifers are often most severely affected, and the introduction of these classes of cattle should be avoided.
“Unlike local animals, any cattle introduced to the coast from inland or southern areas are at risk of being naïve to this disease which can lead to illness or death and potentially render bulls temporarily infertile,” said, Jocelyn.
Current treatment options for cattle that are affected with theileria are limited and responses to treatment are often poor, especially in severely affected animals. Avoid stressing animals that you suspect of being infected with theileriosis to prevent compromising the movement of oxygen in their body any further. This includes avoiding too much movement and ensure they have adequate water and good feed available to them.
North Coast Local land Services recently produced a video about Theileria and how to minimise its impact on your herd. You can watch the video here
https://www.youtube.com/watch?v=Rn8ioaGhdg0&feature=emb_logo
For further information contact your local district veterinarian or private veterinarian.
ENDS
Media contact: Emily Findlay North Coast Local Land Services, 0419221136