Newsletter December 2016
What follows is a sum up of some common farm animal problems we have seen this Autumn. At the top of the list are outbreaks of pneumonia in cattle, particularly stores, and sudden deaths in lambs, again particularly stores.
Sudden deaths in lambs
There have been a number of, mostly store lamb deaths over the last few weeks, and I wanted to take some time to outline the most common causes for these. I suspect there is a far higher number of deaths out there than have come to our attention.
In some cases we have confirmed diagnoses, and in others there is a high suspicion. Where you are looking for a diagnosis in order to help management of problems the best thing you can do, to optimise our chances of finding an answer, is provide us with freshly dead, preferably untreated lambs for post mortem. I have listed them in the order of prevalence this year, within this practice.
This particular worm tends to cause more of a problem in the late Autumn and early winter, due to the cooler temperatures, which it is better able to cope with than some of the other worms. It used to be known as ‘black scour’, and causes just that, but it also reduces feed intake and will slow growth rates, reduce digestive ability and waste and kill worst affected cases. Where fat lambs are going onto permanent, or previously grazed pasture it is highly likely the larvae will be there. They may also not have been fully cleared out with the worming regime previously used so it is essential that when lambs are dying; worm status is considered before anything else.
Remember with the current weather we are still having some fairly warm days, therefore flushes ofthese worms and fluke are likely to still be causing problems. Where you are unsure if you are worming enough, or where you are suspicious of resistance we do FREE worm egg counts on poo, (if you buy your wormer from us), so there is absolutely no reason why you shouldn’t be asking us for advise on worming.
This is most commonly seen in weaned lambs aged 4-8 months but it can occur in adult sheep as well. In lambs it most commonly affects them approximately two weeks after movement to new pasture or after some other dietary change or stress. The sheep become blind and wander aimlessly, in later stages there is lateral recumbency and seizure activity particularly during handling. Death usually takes 3-5 days in untreated sheep but can be quicker. In the early stages treatment can completely reverse the condition. Remember this can affect young cattle as well, but is less common.
Clostridial diseases and pasteurella pneumonia:
We did run over clostridial diseases in last months newsletter, and it can still be found on our website: Remember to use the Clostridial vaccines according to the datasheet, otherwise effective immunity in the lambs cannot be guaranteed. Ovivac P plus is a 2ml injection given subcutaneously, twice, 4-6 weeks apart. Some of the common causes of death this protects against include: lamb dysentery, pulpy kidney, black leg and blacks disease (which affects the liver), as well as two forms of pasteurella pneumonia, which can be particularly severe in freshly transported lambs. A sudden death in lambs could be attributable to any of the above, which makes the vaccine, or a similar one, well worth the money.
Pneumonia in cattle:
As you well know, pneumonia outbreaks usually have a combination of factors triggering serious disease. These include viruses, bacteria, as well as mycoplasma, stress, ventilation issues, underlying problems with immunity and much more. With new vaccines coming on the market all the time it is important to be aware of the different possibilities that are out there to try to help reduce the devastating impact of a pneumonia outbreak.
Traditionally we have been using viral vaccines and they are still a highly important part of management. However, more and more commonly, when we get a chance to do a post-mortem, or further investigation, the bugs we are finding are bacteria. Specifically commensals, that often live in healthy cattle lungs normally. However, in the case of pneumonia these bacteria take advantage of previously (virally) damaged lungs, multiply quickly and spread readily between animals. They also produce toxins, which cause even more damage to the lung, and other tissues, and, in the right conditions, rapid death. At this late stage antibiotics may kill the bacteria but they cannot get rid of the toxins so they are unlikely to save the animal.
The 3 bacteria I am describing, are Mannheimiahaemolytica, Pasteurellamultocida and Histophilussomni. There are vaccinesfor 2 of these, and it might be worth considering adding them to your vaccine protocols.
Finally, going back to other causes, we all know that shed ventilation can really help in the management of pneumonia. It can be useful to do a few calculations to help decide what is needed to improve or perfect ventilation in a building.
Outlet: To work out the required outlet (usually the open space in the ridge of a building) where hot, wet air rises and should be able to escape. All you need are the following figures: area of building, height of the roof at its eaves and at the ridge, and the number and size of animals in the building. Plus a couple of graphs from the booklet detailed below. It is a quick process and doesn’t need to be complicated.
On average the figure required is roughly 0.04m2 per small calf up to 100kg and 0.1m2 per adult or fast growing animal, however the details in the book allow you to adjust for the animals’ weight and the height and size of the building.
Inlet: This should be 2-4 times the size of the outlet, preferably above the level of the cattle so that draughts are avoided, particularly in young calves.
There is a free booklet online with all the information you need to do this calculation and much more: It is called: Better Cattle Housing by the Better Returns Programme, and is worth a read. There are also other sources of the same information.