Workers at the Peninsula Humane Society in San Mateo have accused the agency of understaffing and what amounts to animal abuse and cruelty after several kittens and a dog died while in its care.

About a dozen employees at the Humane Society said animals are being mistreated and even killed in the shelter. But the agency said it’s all inflated accusations in the midst of an employee contract dispute.

The employees' accusations stem from several kittens dying over the summer. The workers said volunteers weren’t properly trained, and that contributed directly to the animals' deaths. Agency managers said the kittens were sick, and there was nothing more they could do.

In another case of what employees call mistreatment, a pit bull named Max was found by animal control officers bloody and trapped, trying to escape his kennel at the Humane Society shelter in San Mateo.

"What I saw was a dog that had it’s neck cut," Animal Control Officer Dylan Skiles said.

Skiles said he requested management inspect all of the kennels weeks before the incident, after a previous incident where a dog was injured trying to escape a broken cage.

Humane Society spokeswoman Lisa Vanbuskirk said in that case, the cage had been broken by the dog, and it was repaired the following day. Vanbuskirk, the agency's senior vice president of development, responded to a number of accusations Monday, including a dog that died after being transported in a vehicle that lacked air conditioning.

"There’s been some unfortunate situations; we’re not happy about any of them," she said. "We feel like there’s reasons why they occurred."

In the case of the dog that died in the truck, Vanbuskirk pointed the finger at an animal control officer.

"Rather than trying to fix the problem of inadequate cooling in the truck, the officer was blamed for the death and fired," Skiles said.

Vanbuskirk also confirmed that several employees were fired last year after a dog was mistakenly euthanized. She believes the so-called whistleblowers are attempting to publicly shame the Humane Society as a political stunt while union contract negotiations are ongoing.

But the employees say they're trying to speak for the animals.

"This isn’t about the money. This isn’t about the contract. This is about the animals," said Vaughn Hyndman, a dispatcher for Animal Control.

The union members who spoke Monday believe the agency's troubles are caused by lack of staffing. Humane Society officials did not have exact numbers for staffing, but there are about five open positions posted on its website.