Then pigeons started dying, and students and teachers became alarmed at the expired birds on the ground. Then the cat found the pigeons. A student discovered this unsuspecting local cat, known to many at the college. It was convulsing. It was unable to retain body heat. The student took it to the Annandale Animal Hospital, to give it a speedier, painless death. Notes taken by the veterinarian, obtained by The Sun-Herald, said the cat was suffering chronic seizures. The vet suspected brain damage. On inspection, it had bones and feathers in its stomach. It had eaten two dead pigeons and was immobilised by the poison that had dispatched them.

The university confirmed it contracted Precision Pest Control to bait pigeons at the campus with alphachloralose, an agent that kills animals by shutting down their nervous system. The cat survived, after having its stomach flushed, but an avian specialist vet, Ross Perry, is worried that other pets in the area may not be so lucky. Dr Perry said there was ''significant risk of secondary poisoning'' by alphachloralose. ''The bottom line is that it is not target-specific. It has the potential to create a lot of suffering for any dog, cat or bird who feeds on the poisoned pigeon,'' he said. The Greens MP for Balmain, Jamie Parker, said the university should have contacted nearby residents, Leichhardt Council and the Sydney Harbour Foreshore Authority to advise them of any risks. ''It is shocking that the apparent reckless action of the university has had such consequences and it raises genuine concerns that the appropriate safety protocols were not followed,'' he said. ''The baiting can inflict collateral damage on other native animals and could kill dogs that are walked in the area if they were to consume a poisoned bird.''

But a university spokesman said ''there are no nearby residents''. As the baiting took place on college grounds, it did not have to alert either the council or the foreshore authority, he said. The authority and the council ''were not informed as this is a legal method of pigeon control that took place within a locked campus, outside of normal operating hours''. The spokesman stressed that the baiting of pigeons was a ''last resort'' and was requested by the Department of Public Works and the Department of Education. ''The pigeon droppings cause significant damage to the heritage buildings,'' he said. ''This has been minuted regularly at the monthly meetings held between the University's Campus Infrastructure Services, Department of Education and Training and Public Works.'' Follow Environment on Twitter