Bleeding Calf Syndrome.

Information is slowly filtering through about this unusual condition that affects calves between two and three weeks of age. The scientific name for the syndrome is Neonatal Pancytopaenia, lack of all cells in the blood stream. It was first identified in Germany in 2007 and has been vigorously researched ever since. Affected calves seem to thrive at first but are then seen to haemorrhage from the nose or mouth, some animals will bleed when ear tags are used and others just seem to ooze blood anywhere through the skin. There is no treatment and no possibility of recovery from this condition, within forty eight hours affected animals will die from internal haemorrhage.

Thorough Investigations

All sorts of theories have been put forwards to find a cause for this condition. Post mortems show haemorrhage any where within the body particularly around the liver and in the chest cavity. It is notable that all of the calves have a low or zero platelet count. Platelets are essential for blood to clot. Examination of the bone marrow reveals that it is severely depleted and not able to produce any red, white blood cells or platelets. Extensive tests to determine if a virus or bacterial infection are involved have all been negative. Both beef and dairy calves are vulnerable to the condition, they tend to be calves that are born on farms that have large number of cattle. All of the cows were vaccinated against BVD and eighty percent of the affected herds use the leptospirosis and Bluetongue vaccines as well.

It is now thought that the calves are in some way reacting against the colostrum they receive from their mother and that an adverse reaction occurs to irreversibly damage their bone marrow. So far in the UK ninety calves have been affected throughout the country, there has only been one case in Wales. Most farms have only reported either one or two animals affected here, but there have been higher numbers from farms in Germany. Strangely there have not been any reports of neonatal pancytopaenia occurring in America. It has been noted that when a calf has died of this condition there is a tendency for it to occur again when the next calf was born. Experiments abroad involved feeding colostrum from an affected cow to four new born calves, two of these animals died including the cow’s own calf.

It is still too early to come to any conclusions as to exactly what is happening here as research is on going. There does seem to be some sort of a link with vaccinations, but it would be wrong to alter your disease control policies as this does seem to be a very rare condition affecting individual cows on larger farms. If you were unfortunate enough to have a case then the obvious remedy is not to give that cow’s colostrum to calves in subsequent years unless further treatments are found in the meantime.

Health Monitoring

There are new rules for the Sheep and Goat Health Schemes now. The Scottish Agricultural College has eased the blood testing requirement for flocks that have been established in the Maedi Visna scheme and do not have non accredited sheep on the farm to every three years. The reason they give for this is to reduce their costs although three years between monitoring visits seems a long time. Flock breakdowns do occur from time to time and it does mean that any animals sold since the last clear test will need to be traced and the flocks monitored. Nobody knows how prevalent Maedi Visna is in the national flock, a limited survey in 2003 in non accredited flocks found that 3.3% showed evidence of infection. The true figure is thought to be far more than this. Data from the Scottish Agricultural College indicate that where there have been flock breakdowns in accredited flocks it happens because there are non accredited sheep or goats registered to the same holding and there has been contact between the two groups or MV accredited sheep from another holding have been brought onto the farm. Don’t forget that all added animals, and that includes any rams, will still need to be tested each year. It can be difficult to remember sometimes when testing is due so keep a close eye on your certificates, it is too late to find that they have expired when you are on your way to a show.

Bio Security Measures

The MV virus is fragile and will only survive for a short time outside the body. It is normally transmitted to other sheep by close contact with the nose of an infected individual. The virus is also present in other body fluids such as milk blood and saliva so you will need to be vigilant at all times. The rules are to keep accredited and non accredited stock separate by a gap of at least two metres, a single gate between different animals is not acceptable. Under certain conditions the virus can survive out side of the animal on pastures so there must be a seven day gap before accredited animals can graze fields that other sheep have been on. It goes without saying that handling facilities and livestock trailers must be cleaned and disinfected before further use and do not share ear tagging equipment and dosing guns between flocks unless they have been vigorously cleaned and disinfected as these too have been shown to be responsible for flock breakdowns.

Worming Revolution

I am pleased to say that after more than twenty five years Novartis has developed a completely new type of wormer for sheep that works in a  different way to any of the other wormers available at the moment. The name of the new compound is monepantel and it will be marketed by the name Zolvix. This drench has been shown to eliminate 99.9% of roundworms in sheep and at the moment there have been no reports of any resistance to the drug. Zolvix is an orange colour and is a completely different class to the other wormers so we now have white, yellow, clear and orange wormers for sheep.

Targeted Dosing

The main role of this new drug will be as a quarantine drench for all newly purchased adult sheep. The recommendations for the sustainable control of parasites in sheep is now to treat everything with Zolvix on arrival. Dosed animals will need to be kept off pastures for twenty four hours before being turned onto a well used field so they have to opportunity to pick up the worms that are circulating on your farm. If you already have resistant worms you will see the benefits of using the drench when lambs are weaned and on all stock once in the autumn. There is no real reason to use this product on young lambs in the spring that have nematodirus as this infection will respond to any of the worm drenches. We will need to be careful about how we use Zolvix. Used with care it has great potential to control resistant worms and enhance to welfare of our sheep flocks.

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