Test and Protect your Flock this Winter
In our second vet column focussing on seasonal animal health, we hear from Chris McGregor from Tinto Farm Vets, who highlights what can be done to prevent deaths within your flock this winter.
With the uncertainty of Brexit just around the corner, who would have thought this autumns sheep trade would have been so buoyant?
Prices for both breeding and store sheep have strengthened significantly making the risk of any fatalities over the winter months a bigger hit on the pocket than usual.
With the most common causes of sudden death in sheep, particularly lambs, being treatable or preventable conditions, it is important to be aware of them and be prepared to act if you do experience any losses on your farm. From a simple on farm post-mortem (PM) your vet will often be able to make a diagnosis so action can be taken to reduce any further losses.
So far this year, the most common condition Tinto Farm Vets have diagnosed, by on farm PM is pneumonic and systemic pasteurellosis. These conditions are caused by the Pasteurella family of bacteria and can either cause a severe acute pneumonia or a generalised septicaemia affecting multiple organs.
Sheep with the condition are rarely seen alive, with progression from a healthy animal to death taking as little as a few hours. The causative bacteria can be detected in healthy sheep, so outbreaks are often seen after significant stress such as a change of group or field. Periods of particularly bad weather can also predispose lambs to the condition. Vaccines are available for prevention however if faced with an outbreak within your flock, antibiotics may be required to stop any further losses.
Fluke has received a lot of publicity over recent years and although we are much more aware of the problem, its occurrence is still too common.
It is important to remember that fluke is not an individual animal disease and if lambs in a group are dying with acute fluke (i.e. the migration of immature fluke through the liver) there is likely be a significant reduction in the growth and efficiency from the remainder of the batch.
Due to the life cycle and environmental conditions fluke requires to thrive in, each case is different every year and on every farm. Therefore, it is important to think carefully about the optimum timing and the correct product to use when treating.
This year, we blood sampled a batch of lambs on the 2nd September to test for exposure to fluke. All lambs tested positive meaning they picked up fluke from around mid-August, if not before, much earlier than the farmer was expecting. Therefore, on this occasion it showed treatment was required and timing was correct.
Unfortunately, a blood test is only useful in lambs to look for the first exposure of fluke, in their first grazing season. Once a sheep has antibodies and tests positive it will continue to do so for the remainder of its life.
Of course, there are other causes of death in sheep and lambs over the winter months - the important message is don’t accept any losses as 'normal' as many of the conditions are preventable if you know the cause. The cost of a on farm PM will be less than the value of a lamb so they are a cost-effective way of diagnosing a problem.
Deaths and causes should be recorded and then discussed with your vet at your annual health plan review. Together you will then develop a suitable control strategy for each disease found on your farm.