Bleeding Calf Syndrome
Bleeding Calf Syndrome
Many beef producers will now be aware of a new disease of young calves, first seen in 2007; the first symptoms were often calves bleeding from injection sites and after tag insertion. The disease is now called Neonatal Bovine Pancytopaenia (NBP), but is still the same disease syndrome and this is the name used in the international press when describing the condition.
This practice first saw the condition in 2007 on 2 farms - at that time the cases were considered novel but likely to be isolated incidents, and similar problems had been seen on rare occasions in the past. Again a few isolated cases occurred in 2008. We saw a marked increase in 2009 in both the number of calves affected and farms involved. So far in 2010 the number of affected calves has increased considerably - both in terms of number of calves on previously affected farms and new cases in farms not previously affected. Last week in the Kelso branch we had 8 confirmed deaths on 4 farms. As I write this I have today seen 3 affected cases on one farm, and 5 suspicious deaths are under investigation at the lab in St Boswells. This increase has been seen in other vet practices and SAC laboratories especially in the eastern side of Scotland. Some parts of Scotland have yet to recognise the disease and it has also been recorded at low levels in some parts of England.
The disease affects mostly spring born suckled calves, although we have seen it in autumn born sucklers, and it has also been seen in dairy calves, but at a lower incidence level. Most calves become ill between 10-24 days of age - in some obvious bleeding is seen, perhaps from the nose, rectum, tagging sites or after injections. Some are just found dead, others look like cases of pneumonia and/or coccidiosis. In most cases we have seen, treatment including blood transfusions has been futile, and now when we suspect the disease euthanasia is often the kindest option. At the moment I am aware of 3 surviving calves that are coping well, but it is not known if they will make a full or partial recovery or just succumb to the disease or another illness at a later date. It seems that calves that present with a temperature and anaemia but with no other symptoms are best placed to survive.
They need to be housed with their mothers, kept as stress free as possible and fed/hydrated as needed. Antibiotic cover is also needed, they have little protection against simple infections.
The condition is of progressive destruction of the bone marrow in these calves, thought to start at birth, all the white cells that protect against infection are destroyed first, and then the little cells that are needed for the blood to clot naturally also are destroyed/disappear. So over a 10-14 day period affected calves become slowly weaker and reluctant to suck as their anaemia increases, often have a high temperature and eventually become profoundly anaemic and die. Often the uncontrollable bleeding is internal with no visible signs.
If you suspect this illness in calves from 10-28 days of age, it is vital we examine the calves to see if they are becoming anaemic. It can be very tempting to assume it is a simple case of pneumonia and self treat. However it is vital to understanding the disease that we identify all new farms and cases as they occur. A simple blood check for the % of blood in the body gives a quick answer; this test can be done at any of the clinics. Further blood will be sent to Greycrook. In all new suspect cases the body of the calf should go to Greycrook for a definitive diagnosis - this is paid in full by the Scottish Government. For repeat cases on farms this is not necessary, but we would still like to test these calves for the signs of the disease - this may just involve taking extra blood samples, or if dead a post mortem to collect pieces of the breast bone, ribs and one of the leg bones, the femur. The disease can be diagnosed effectively from these samples. We will then submit a separate report to the Veterinary Medicines Directorate.
This disease is not confined to Scotland or the United Kingdom. It has been reported in many European countries, with the majority of cases occurring in Germany. Little is known or understood about the multiple causes of the disease, other than it appears to be related to the intake of colostrum, and that it is an immune system malfunction that attacks the bone marrow of the calf causing the symptoms. In Germany as in our own practice it is seen in herds that often use multiple vaccinations to control disease, often given in multiple injections prior to calving. One vaccination in particular is very common, that is against BVD virus - we have certainly seen a massive rise in the number of vaccinated herds in the last 4 years.
Although many factors are almost certainly involved in this disease, it would appear statistically that farms where Pregsure BVD has been used may experience the disease more frequently compared to other BVD vaccines or where no BVD vaccine has been used. In our practice virtually all the affected farms use a combination of vaccines, usually pre-calving. Almost all use Pregsure, some Rotavec, some Leptavoid H, but in one case no BVD vaccines have ever been used. One vet practice close to Kelso has only seen one case; another practice has yet to recognise the disease. We have several severely affected farms in a cluster in one area, but a farm in the middle of this cluster using the same management and vaccine protocols has yet to see a case. In the west coast of Scotland vet colleagues are only just beginning to recognize and report cases. The exact cause is still very far from being known, so many factors could and will be involved. It is extremely demoralising for affected farmers, this disease is killing calves at an age when little usually goes wrong - we do not know the cause and we do not have any treatments. Recently in an attempt to help investigate the disease in Germany, Pfizer voluntarily decided to stop selling the Pregsure vaccine in Germany.
The majority of farms have not yet been affected by this disease and hopefully may never be, despite following similar management/feeding/breeding/calving systems to affected farms. For affected farms the disease is worrying, depressing, creates sadness and will lead to high financial losses. A worrying pattern is that once cases have occurred on a farm, they will repeat the next year and it is becoming clear that cows that deliver calves that develop the disease will produce calves that develop the disease in following years.
BVD infection is a very serious disease in the UK and vaccination is a vital element of control. For many many farms the threat from BVD infection is much greater than the risk of bleeding calves. However, in view of the increasing number of cases of NBP seen in this area of Scotland we have decided to temporarily stop prescribing Pregsure BVD vaccine and replace it with Bovilis BVD for herd control. Please note this is a 2ml intra-muscular injection, not under the skin. We have been assured by the manufactures that Bovilis BVD can be used successfully as an annual booster to previously Pregsure BVD vaccinated herds. However please note that the initial course of 2 injections separated by an interval of 4 weeks must use the same vaccine for both injections.
Pregsure has been a very successful BVD vaccine since its launch in 2005, and we have not taken this step without careful consideration. It is vital that research into this disease continues, particularly the role of the large number of biological vaccines available for and needed in cow herds today. We need to consider the effects of multiple vaccinations to late pregnancy cows, and find practical solutions to space out vaccinations.
The hope is that temporarily stopping sales of Pregsure in the most affected country will quickly contribute to our understanding of the disease. We are aware that the alternative BVD vaccines are having supply problems, so please order early and it may be that the most suitable pack sizes are in short supply. We will do our best to keep you informed of any supply issues.
If you have any further questions please do not hesitate to contact your usual farm vet for more advice.
Robert Anderson