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POST-PARTURIENT HAEMOGLOBINURIA Post-parturient haemoglobinuria is a disease of high yielding dairy cows which occurs within a few weeks of calving, and is characterised clinically by red urine and marked reduction in milk yield. PREVALENCE Post-parturient haemoglobinuria affects only dairy cows particularly those which are high yielding. It is rare in young animals and is usually seen in cows which have had at least three calves. The majority of cases occur around three weeks post-calving (range 10-40 days post-calving). In most countries the peak incidence of the disease is during the later winter (i.e. January to March) but in the U.K. it has also been observed in the early summer (May and June) when pasture conditions have been poor. Although outbreaks can occur, with each successive calving cow of the correct age being affected, the usual situation is that only one or two animals show clinical signs. CLINICAL SIGNS Red blood stained urine is usually the first clinical sign, but this is rapidly followed by inappetance and a marked drop in milk yield which may be the first signs recognised. Initially the animal becomes pale but jaundice soon becomes evident. The jaundice is frequently severe. There is marked effects on the cardiovascular system. Constipation is usual and any faeces which are passed tend to be dark in colour and covered in mucus. Fever is not a feature. Affected animals are dull and extreme weakness with a staggering gait is common. Recumbency often ensues. If death occurs then it usually does so within the first 36 hours of the appearance of clinical signs. The mortality rate is variable, but as many as 60% of affected animals can die. Those which do not die start to show obvious signs of recovery within 5-7 days. Recovery is usually complete within 3 weeks but full milk yield is seldom attained.DIAGNOSIS Diagnosis is based on history, clinical signs and where necessary laboratory findings from blood tests.. TREATMENT Where possible transfusion of blood should be performed. However, it should be remembered that other cows on the farm may be anaemic although not showing obvious clinical signs and thus the donor animal(s) should be carefully selected. The possibility of transmitting other diseases by blood transfusion should be considered. Phosphorus salts can be administered as a solution subcutaneously, intramuscularly or intravenously. Compound preparations containing calcium, magnesium and phosphorus contain phosphate salts at a much lower concentration than Foston. Supplementation of diet with bone meal. PREVENTION If animals are fed an adequate concentrate supplement then the condition will be virtually eliminated. Supplementation of the diet with phosphorus, e.g. by use of bone meal. |
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