The RSPCA has received dozens of calls from frightened pet owners who fear their animals will be mistakenly killed under the Victorian government's new law on dangerous dogs.
But a child safety group has welcomed an early end to the amnesty on registering restricted dog breeds following the death of four-year-old Ay en Ch ol, who was mauled by a neighbour's pit bull mastiff in her living room two weeks ago.
Under the new rules passed through parliament on Tuesday, any pit bulls or other restricted breeds not registered by September 30 will be seized and destroyed by local councils.
The legislation will also make pit bull crosses a restricted breed.
And proposed changes to Victoria's criminal law next month will have dog owners facing up to 15 years' jail, or similar penalties to culpable driving, if their dog injures or kills a person.
RSPCA Victoria CEO Maria Mercurio said while she welcomed the government's move to protect the community from dangerous dogs, it was extremely difficult to identify dog breeds by sight and mistakes could be made.
"Unless you do DNA testing, even then it's very difficult if you have a number of breeds that have been crossed," Ms Mercurio told AAP.
The organisation had received dozens of calls from worried pet owners, she said.
"People are frightened that their dogs will be mistaken for a pit bull or for a dangerous breed when in fact they're not," Ms Mercurio said.
"While legislation is important and we support the government in that, we would like to see an equal emphasis on educating our community so that we have good, responsible pet owners."
Kidsafe state manager Melanie Water hailed the changes as a positive start.
"At least one child a day is taken to hospital as a result of a dog attack in Victoria," Ms Water said.
She called on families with dogs to ensure pets are well-socialised and trained from a young age, and said children should never be left alone with dogs.
The minister responsible for animal control, Peter Walsh, said a tighter standard for identifying pit bull terriers would be released to prevent uncertainty over their breed.
"If someone believes that they have not got their dog registered appropriately under the new standard, they need to get that normalised before the 30th of September," Mr Walsh said.
"Because councils, if it's reported, will seize that dog and destroy it."
Mr Walsh said Victorians have made it clear that they don't want these types of dogs in the state for longer than necessary.
Under the new law dangerous dogs will have to be desexed, microchipped and will have to be on a leash and wearing a muzzle when taken for walks.
So far, about "two or three" unidentified councils in Melbourne are in need of assistance with unregistered, restricted dog breeds, he said.
Municipal Association of Victoria CEO Rob Spence said councils and the rangers enforcing the new laws would be guided by the state government on how to identify dog breeds, especially in ambiguous cases where cross-breeding is involved.
"The standard I think will be reasonably easy to interpret," Mr Spence said.
Peter Lewinsky from Brimbank City Council said the new laws would be a relief to the St Albans community who were still coming to terms with Mayen's death.
He said the government should help to fund the extra staff needed by councils to enforce the legislation.
A "dangerous dog" hotline on 1300 101 080 has opened for people to report dogs they believe to be restricted.
Parliament was told on Tuesday that there were 122 calls made to the hotline on its first day.
Calls to the American Pit Bull Terrier Association of Australia were not returned on Tuesday.