Green Island Vet Clinic staff recorded 34 confirmed cases of feline immunodeficiency virus (FIV) in the past three years, concentrated largely in Brighton, Green Island, Corstorphine and Kaikorai Valley.
Staff at Helensburgh Veterinary Clinic had recorded "about 30" other cases in the past year alone, mainly in Maori Hill, Helensburgh and Roslyn.
Helensburgh clinic veterinarian Jon Hepburn said the figures included a "little spike" of about eight confirmed cases in the past three weeks.
FIV was now the second most common cause of premature death among cats (being hit by vehicles was the main cause), he estimated.
The viral infection - from the same family of viruses as Aids - attacked cats' immune systems, making them vulnerable to secondary infections and, ultimately, death, veterinarians spoken to yesterday said.
Most clinics contacted dealt with a regular trickle of "one or two" confirmed FIV cases each month, although exact infection rates were difficult to ascertain.
Estimates ranged from 10% to 20% of all cats, with strays and unneutered tomcats most at risk.
Gardens Vet Clinic owner Russell Brown said the infection, which was carried in blood and saliva, was often transferred when cats fought, scratching and biting each other.
Some FIV-positive cats were "wasting away" through repeated secondary infections, with symptoms including poor coats, eye infections and lethargic behaviour, he said.
"I would not say it's rampant, but there's quite a significant occurrence of it," he said.
United States-based pharmaceutical company Fort Dodge Animal Health has developed a vaccine to protect healthy cats, which was available in Dunedin.
However, there was no known cure for infected cats, which could appear healthy for up to 10 years while harbouring and spreading the disease to other cats.
It could not be passed to humans.
Green Island clinic owner Scott Drummond said he hoped to raise awareness about the virus and vaccine, and a map with pins showing FIV "hotspots" in Dunedin had been placed in his clinic's foyer.
Brighton was the worst "hot-spot" in Dunedin, with 10 cases in the past three years - including four on the same street, he said.
"For 10 cases to be in a small community like Brighton, that's really high," he said.
"There's likely to be more out there."
Staff at the Helensburgh clinic had also placed a map marked with pins in their foyer, to raise awareness, Mr Drummond said.
Mornington Veterinary Centre principal veterinarian John Keenan, whose clinic saw "a couple" of confirmed cases each month, said a blood test and series of vaccination jabs was available at a cost of about $190.
Owners of pets with "full-blown Aids" had to choose between taking no action, keeping their pet indoors or euthanasia, he said.
"You have got to weigh the situation up," he said.
"That's got to be the client's decision."
