'Zoo blackbucks died of hydrocyanic acid in plants'

LUCKNOW: The argument continues over what caused death of 18 blackbucks in Lucknow zoo. The second report by the Indian Veterinary Research Institute (IVRI), Bareilly has substantiated the first which said a toxin hydrocyanic acid (HCN) in the fodder caused the black bucks to die. The zoo administration, on the other hand, is hell-bent on proving that HCN is naturally found in plants. The argument could be to brush aside the insinuation that the toxin was introduced in the fodder from outside in a lapse by the zoo administration.

The probe into cause of death of the blackbucks, protected under schedule (I) of the Wildlife (Protection) Act, continues. The IVRI has said in its diagnosis, "keeping in view the result of various laboratory investigations, the cause of recent mortality in blackbucks at Lucknow zoological park is attributed to hydrocyanic acid toxicity leading to hypoxia/anoxia."

HCN is a cyanognic-glycoside which could be present in the fodder that comprises sorghum/jowar and maize and is a common cause of poisoning in grazing ruminants. The concentration of HCN in plants is immature. "Usually, during summer, growth of fodder remains generally stunted and accumulates cryogenic glycosides when it grows right after the rains."

The IVRI report said it's the seasonal change which leads to toxins getting accumulated in plants naturally and factors like frost, mist and witling favour the accumulation of HCN in plants. But, isn't it the responsibility of the zoo administration to ensure that fodder given to the animals is checked and monitored, especially during inclement weather?

Dr Parag Nigam from the Wildlife Institute of India ( WII) has been treating blackbucks at the zoo ever since they started dying. He said, "The findings of IVRI have indicated presence of HCN in fodder and ruminal contents. This may be considered as one of the stress factors flaring up infection in the blackbuck population."

The mortality occurred possibly due to disease (bacterial or viral) as the clinical signs and post mortem findings revealed consistent respiratory involvement, said Dr Nigam. While the cause of death of black bucks might still not be known, zoo administration does not stop short of claiming that it controlled the disease and its spread appropriately. Considering that prevention is better than cure, Lucknow zoo failed to act on time.