New microchipping laws may be to blame for an increase in the number of dogs being dropped at the South Auckland SPCA centre, its manager says.

The law, which came into effect on July 1, requires microchipping for all dogs first registered after that date ; unregistered impounded dogs; dangerous or menacing dogs; and registered dogs impounded more than once.

In June, 365 dogs and puppies arrived at the centre needing new homes, compared with 300 in June last year, Mangere Animal Village general manager Jane Thompson said.

The microchipping law, winter weather and financial strain could all be blamed for the influx, Ms Thompson said.

Registration fees in Auckland range from $38 to $106, depending on whether the animal was de-sexed or the owners held a dog licence.

A one-off microchipping fee ranged from $40 to $80, depending on the veterinary clinic.

"There's a lot of people struggling financially and have to give up their dogs, and for those people that are really stretched the dog's the one that suffers," Ms Thompson said.

She said it was typical at this time of year for the numbers of dogs abandoned to climb.

"We always get a lot of dogs coming in when dog registration is due, usually around July."

She said the centre had offered to microchip dogs when they were reunited with their owners.

"When dogs come in - ones hit by cars for example - and they are reunited with their owners, we offer to microchip them for them, and so far we've had a really good uptake of that."

A worrying statistic, she said, was the number of neglected, skinny dogs removed from their homes last month - 62 compared with only eight this time last year.

People grow tired of having dogs in the winter, "they don't like to have to take them for walks and look after them, with muddy paws from muddy backyards".

The centre faced a "crisis" mid-June when they had to turn puppies away, asking people to return them the following week or try to re-home them privately.

"We get a bit full at times," she said.

Publicity about a centre foster programme had saved it from overcrowding.

People can foster puppies when they are too small or young to be re-homed.

"They'll go out to foster for three or four weeks and then they come back little, fat, furry happy puppies," she said.

"There was an excellent response to the foster programme publicity, and we got through the crisis," Ms Thompson said.