The Charleston Animal Society is offering free adoption of adult dogs and cats, and an adopt one, get one free on kittens to reduce the hundreds of animals it has at its "no-kill" shelters.

Adult cats and dogs can be adopted for free at the North Charleston shelter, and kittens can be adopted at the shelter and PetSmart on Longpoint Road in Mount Pleasant.

Kittens make up the largest group of adoptable animals, with more than 100 available between the two locations. The shelter typically sees a large influx in the number of kittens in the early summer when feral cats have litters.

Adult dogs put the most pressure on the shelter, Chief Executive Officer Joe Elmore said.

"We just don't have any more room," Elmore said.

While the shelter does not receive many puppies due to extensive spay and neuter efforts, adult dogs tend to come in more often and are sometimes hard to adopt out.

The shelter defines adult as more than 1 year old, so many of the 75 available dogs "still have that puppy personality," Elmore said.

This is the third consecutive year the shelter has had adoption promotions in June to alleviate pressure from overpopulation. Last year, 538 animals were adopted from the shelter in five days during the promotion. Elmore hopes this year's promotion will yield similar results.

There currently are about 750 animals in the shelters and in foster care.

"We're just trying to provide financial incentive - a gesture of appreciation for people to make room for one more in their home," Elmore said. "We can't wait any longer. We're in crisis mode."

Reach Amanda Coyne at 937-5592 or on Twitter at @AmandaCCoyne