Severe cat flea infestation of dairy calves in Brazil.

An investigation was conducted into a severe flea infestation on dairy calves. Inspection of the dairy revealed a high infestation of Ctenocephalides felis felis on four calves and thousands of fleas in the stable where cows and calves were brought in for milking. A 3-month-old female calf was highly infested with fleas. The animal showed an evident lethargy, weight loss, as well as pale mucous membranes and dehydration. Hematological analysis revealed anemia, with 10% packed cell volume and a 1.72 x 10(6) microl(-1) erythrocyte count. Blood transfusions were performed and the flea infestation was controlled with 1% fipronil pour-on (1 ml/10 kg). The farmer was advised to treat the other calves with fipronil, remove the manure from the stable and spread 1% propoxur powder (100 g/m2) onto the floor of the stable.