Yersiniosis in deer
It would be fair to say that every weaner deer in New Zealand will be exposed to the Yersinia bacteria in their first autumn/winter. This is because the bug is carried by birds, rabbits, rodents, hares, sheep, cattle and pigs and can survive well in soil, water and pasture during the winter months.
How young deer are managed during and after weaning will determine whether or not they succumb to the disease. Anything that stresses the animal such as transport, bad weather, poor nutrition, trace element deficiencies or parasites can cause clinical disease. Animals with no major stressors will usually not present with full-blown clinical disease and show only mild symptoms.
The symptoms of yersiniosis in fawns are a foul-smelling, watery scour that progresses to a bloody diarrhoea and usually death. There is seldom the opportunity to treat a sick animal because of the speed of onset of the disease and in the case of an outbreak, it is not uncommon for 20% of a mob to be affected. In an outbreak, it is usually too late to vaccinate and prophylactic antibiotic therapy given to the remainder of the mob may be the only approach.
Aim to reduce stress levels as much as possible in young deer and consider reducing stress levels on yourself by vaccinating your weaners with Yersiniavax® [Prescription Animal Remedy (P.A.R) Class I, registered pursuant to the ACVM Act 1997, No. A6151]. The timing of vaccination may be critical in determining its effectiveness. Ideally it should be done in the autumn before the bad weather and young deer have been mobbed together. The single factor that often has the greatest bearing on when to vaccinate is when weaning takes place. Vaccinating before weaning can be challenging, yet leaving deer unprotected until after the rut could lead to problems.
Please give Totally Vets a call to discuss these issues.
