Denise Connor's five Pomeranian pooches were in the back garden playing when the worst happened.

A 1.5-metre long brown snake slid into the yard and bit one of the dogs Spanky.

Ms Connor's grandson Deklan Rainbow, 15, was at the home and heard the attack.

"The dogs were in the yard and they started barking," he said.

"I started to walk out to see what was going on and I heard Spanky yelp.

"The snake was five foot long and had come right up to the back of the house."

Deklan got the dogs to a safe place and watched the snake until it left the yard, but in the meantime Spanky had started to convulse.

It was too late to save the four-year-old dog and he died.

"It was very hard," Ms Connor said. "I wouldn't wish the pain of losing a fur baby on anyone. It's so sad knowing there was nothing we could do to save her."

Ms Connor has shared her story to warn other residents to be vigilant with their pets.

She said there were a lot of walking tracks in the nearby reserve, where the grass was long.

"A lot of people walk their dogs. I just want them to be careful," Ms Connor said.

The hot weather is a sign that snake breeding season is under way, making it likely the reptiles will be out across the Hunter.

According to data released by Petbarn, snake bites are one of the most common causes of death among dogs.

The venom causes paralysis, but early signs a dog has been bitten include vomiting, panting or breathing difficulties, swelling and convulsions.

Residents who find a snake in their yard are encouraged to stay in a safe place and watch the reptile to make sure it leaves the property.

If it does not leave, contact a registered reptile handler to have it removed.

The Office of Environment and Heritage has a list of licensed reptile handlers on its website at www.environment.nsw.gov.au.

Spanky has since been buried in her favourite spot in the garden and Ms Connor has kept a close eye on her other four dogs.