Metaphylactic deworming program for buffalo calves (Bubalis bubalis) in North-East Thailand.

One hundred newborn swamp buffalo calves (Bubalis bubalis) from three villages in North-East Thailand were divided equally into treatment and control groups. Treated calves received two doses of a piperazine/thiabendazole mixture (196.6 and 50 mg/kg bodyweight respectively) at three, and again at ten weeks of age. Control calves received placebo treatments at the same times. Egg excretion rates for the roundworms Strongyloides papillosus and Toxocara vitulorum were recorded as high as 85% and 58% respectively during the first three months of life. During the trial period, four calves in the treated group died and one was treated for coccidiosis, compared to seven deaths and nine additional anthelmintic treatments required in the control group. All calves that either died or required additional anthelmintic treatment showed signs of severe enteritis, anorexia and emaciation that was attributed to parasitic infestation. Calves receiving emergency anthelmintic treatment all recovered uneventfully. All except four of the calves that died or became sick did so between 25 and 40 days post partum, with the remainder developing clinical signs of parasitosis before day 50. There was no difference in weight gains between treated and untreated calves over the trial period (16 weeks). Thus, the advantage of anthelmintic treatments as described at three and ten weeks of age in buffalo calves under village conditions was seen as a reduction in the combined morbidity/mortality rate from 32% to 10% (P less than 0.05). From the pattern of infection observed in this study it is suggested that further gains could be made by giving the second treatment at six (instead of ten) weeks of age, and by increasing the dosage of anthelmintic used.