On separate occasions, Myrtleford resident Nicholle Nolan found the baby animals dead in black plastic bags at Rotary Park which borders the Ovens River.

Her pet dog Turbo sniffed a bag with two kittens in scrub in early July and then at the end of the month detected a bag with two puppies inside lying half in the river.

"It was very upsetting that someone would do something like that, it made me angry," Miss Nolan said.

She guessed the cats were four to five weeks old and the dogs eight to nine.

Alpine Council's director corporate Nathalie Cooke was appalled by the finds.

"This behaviour is inhumane and illegal," she said.

"In any situation when animals are clearly dumped, the police should be contacted, as well as council.

"If live animals are found, council can be contacted at any time and the animals may be collected and suitable arrangements made for their care."

Miss Nolan said she had not reported the finds to police or the council but hopes telling of her experience will cause a rethink.

"Maybe it will stop happening, I just hope I don't find something like that again," she said.

The Prevention of Cruelty to Animals Act 1986 states a person who commits an act of cruelty which results in the death of the animal faces a penalty of up to $82,500 or two years in jail.

The act also states that a person who abandons a domestic animal is liable to penalty of up to $41,250 or imprisonment of 12 months.

In these cases it may have been hard to prosecute a case, given the cause of the animals' deaths was not clear through obvious harm.

However, Ms Cooke noted each July council joined with vets to offer a discount for desexing when tied to registration and microchipping.

"Not only does this assist unwanted litters, but increases the chance of animals being reunited with their owners through pet identification," she said.