Sunday, June 13, 2010

Cow Products - Why ?

Bovine Neonatal Pancytopaenia (BNP) is a newly emerging disease syndrome of calves less than one-month-old which has recently been reported in Britain and Europe.
It is often referred to as calf haemorrhagic disease, haemorrhagic diathesis, bleeding calf syndrome or blood sweating disease.
The first cases of the condition were reported in Germany in 2007.Since then, reports of confirmed cases have slowly risen in a number of European countries while the first confirmed case was recently diagnosed in Ireland and there have been four cases confirmed in Northern Ireland to date.
Typically, the clinical signs in young calves can include excessive bleeding from small abrasions of the skin, or even from injection sites, and the passing of large clots of blood in the dung.
Calves affected with the condition normally have a high temperature and become rapidly depressed. In the majority of cases, death follows within 24 to 48 hours (mortality of about 90% is commonly reported), with aggressive veterinary treatment, including blood transfusions, normally providing only a temporary respite for the animal.
The disease syndrome tends to affect single calves in a herd although multiple calves have been affected in some herds in Britain and Germany.
Affected calves tend to be found in larger well-managed herds with a large proportion of affected farms also keeping sheep as well as cattle.
Within countries that have identified cases, a geographical pattern to the occurrence of the disease has not been identified nor has any breed or gender association been established.
On post mortem examination of affected calves, significant damage to the bone marrow has been consistently reported.
The bone marrow is responsible for producing the blood cells. Red blood cells are responsible for transporting oxygen, while white blood cells play a role protecting against infection. Platelets are responsible for blood clotting.
Of these three, the platelets are most severely affected, giving rise to the typical clinical signs of poor clotting and widespread bleeding in the calf.
While the cause of the condition is unknown, there is no evidence that the condition is infectious or that it gives rise to food safety concerns.
The fact that apparently normal calves at birth can develop clinical signs rapidly after consuming colostrum has focused the attention of researchers on colostrum. It is possible that colostrum acts as a vehicle for the introduction into the calf of the agent which damages the bone marrow.
During the 24 hours that follow the birth of an animal, the intestine allows antibodies (a form of defence against disease) which are contained in the colostrum to pass from the gut into the blood stream. This is an important step in the transfer of immunity from the mother to her offspring and plays a vital role in preventing disease in the newborn calf.
It is possible that, in a very small percentage of calves, some of these antibodies target the bone marrow cells, leading to the clinical signs of the disease. Indeed, a similar mechanism is known to cause destruction of blood cells in some newborn foals and piglets. Researchers wish to ascertain whether this is the case in affected calves and, if so, to determine what has changed in the cow or her environment which has led to the occurrence of the condition.
The Department of Agriculture, Fisheries and Food's regional veterinary laboratories are available to assist herdowners and veterinary practitioners with laboratory diagnosis and investigation of any suspicious cases.
The Department has offered to provide free post mortem examinations of any young calf with clinical signs typical of the condition.
While the condition is rare, with minimal losses to date, the Department is always vigilant to the occurrence of novel diseases or novel presentations of existing diseases. Herd owners are asked to notify their veterinary practitioner of any young calves with apparent clotting difficulties.

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