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Bleeding calf syndrome

(also known as bovine neonatal pancytopaenia (BNP), formerly idiopathic haemorrhagic diathesis)

Q1:  What does the disease look like?

Clinical signs in calves include bleeding from apparently intact skin and also from injection and ear tagging sites together with signs of bleeding from visible mucous membranes, nose and rectum. 

VLA has made several images available.

Q2:  What causes the disease?

The symptoms are caused by an almost complete destruction of the bone marrow of the calf, which produces the red and white blood cells and blood clotting cells (platelets)

A Defra-funded case-control study and another study carried out in Germany have provided evidence of an association between the use of PregSure BVD® vaccine in the dam and the occurrence of this syndrome in her calf. In light of this association with PregSure BVD®, we believe the threat of bovine neonatal pancytopaenia (BNP) to our national cattle herd has been mitigated by the withdrawal of this vaccine from the European market in 2010. The exact role of the PregSure BVD® vaccine is uncertain and it must be borne in mind that, although case-control studies can reveal associations between certain exposures and a disease, they do not confirm causation.

There is evidence that the disease follows the ingestion of colostrum by the calf. It is thought that BNP is an immune-mediated disease associated with absorption of maternal colostral antibody that reacts with cells in the bone marrow of the calf. There is currently no evidence of an infectious component.

Q3:  Does the disease lead to death?

Only a few calves have been affected in any one herd, but once affected they usually die.  However there are reports, mainly anecdotal, of some affected calves making a full recovery.  Only calves less than four weeks old are affected.  The mothers of the affected calves are usually perfectly healthy.

Q4:  How many case of this disease have occurred in Great Britain?

England and Wales: During 2009, BNP was diagnosed on 3 beef farms and 26 dairy farms . In 2010 the condition was confirmed on 16 beef farms and 65 dairy farms. A further one beef farm and 10 dairy farms saw the condition in both 2009 and 2010. In 2011, up until the end of March, BNP was seen on two more dairy farms and one dairy farm that saw the condition in 2009. .

Scotland: BNP was diagnosed on 19 farms in 2009, 108 farms in 2010 and 3 farms in 2011 up until the end of March. 8 farms saw cases in both 2009 and 2010 and one farm saw cases in both 2010 and 2011. The condition was recorded on a total of 28 dairy farms and 114 beef farms.

The number of affected calves in each herd is usually low (less than 1%) and there is no evidence of spread between animals.

Q5:  Is it on the increase?

More cases were confirmed in 2010 than in 2009 and cases are continuing to be seen in 2011.

Greater numbers may reflect better awareness by farmers and private veterinary surgeons as a result of efforts by AHVLA and the Scottish Agricultural College (SAC) to comprehensively record and investigate the condition. There is no legal requirment for farmers to report this disease to Government veterinary authorities and the true prevalence of the disease in British calves is unknown.

Q6:  Does the disease occur in other countries?

Yes, cases have been reported in Germany, Belgium and Holland since 2008 although investigation suggests that the disease has been seen on some farms in Belgium since 2006.  Cases have also been reported in France and Italy.

Q7:  Is there any risk to humans through contact or food?

As the age of the animal affected is 0 – 4 weeks, they would not be entering the food chain.  The age they are affected is very consistent and the disease has never been seen in older animals.

To date no infectious agent (known or novel) likely to have caused the condition has been identified in any of the tissues of affected calves.

There has been no direct evidence or reports of any potential transmission to people in Germany where the disease has been present for at least 18 months.

There is currently no evidence to suggest that the disease is infectious or contagious.

The Human Animal Infections and Risk Surveillance (HAIRS) group, which routinely meets to assess any risks to human health from emerging diseases, has been briefed and are considering the available data.  

Q8:  What is being done to find out more about the disease?

Defra and the Scottish Government have funded research by AHVLA and the SAC to look at the potential factors which might be causing the disease. This included a case-control study and this is now completed. Please see the following documents below:

An international meeting took place in December 2009 in Marseille, France, to consider what is known about the condition and to identify the best way forward in collaborative investigation. Since that time a number of research groups throughout Europe have been engaged on various lines of research and some of their published results are available as below:

  1. Friedrich A von et al, 2009, 'Increased incidence of haemorrhagic diathesis as a result of bone marrow damage in young calves'. Tierarztl Umschau 64, 423-431.
  2. Bridger PS et al, 2011, ‘Detection of colostrum-derived alloantibodies in calves with bovine neonatal pancytopenia’. Vet Immunol Immunopathol. 141(1-2):1-10.
  3. Pardon B et al, 2011, ‘Sera from dams of calves with bovine neonatal pancytopenia contain alloimmune antibodies directed against calf leukocytes’. Vet Immunol Immunopathol. 141(3-4):293-300.
  4. Friedrich A et al, 2011, ‘Ingestion of colostrum from specific cows induces Bovine Neonatal Pancytopenia (BNP) in some calves’. BMC Vet Res. 7:10.
  5. Bastian M et al, 2011, 'Bovine Neonatal Pancytopenia: Is this alloimmune syndrome caused by vaccine-induced alloreactive antibodies?' Vaccine. May 24. [Epub ahead of print] doi:10.1016/j.vaccine.2011.05.012

Q9: What should farmers do if they see the symptoms in their herd?

They should consult their own vet who can submit calves to their local VLA or SAC laboratory for a full examination.