A dog collapsed after eating a 'toxic substance' while on a walk in Chorleywood Common last weekend.

Chilli, a seven-year-old Schnauzer, was walking with her owner Peter Stainer and his two teenage daughters in the popular common on Saturday at about 3.30pm.

Mr Stainer recalls how his beloved pet appeared happy and healthy while running around.

Shortly after leaving the common, at about 4pm, Chilli collapsed and her breathing became erratic.

Mr Stainer, of Penn Close, said: "She was running around as normal off the lead. She was drinking from the puddles as dogs do and we didn’t see her pick anything up at all. We left the common and walked across the road when my daughter noticed she was dragging one of her legs.

"I thought there might be something stuck in her paw, but within a minute her legs started to wobble and she just hit the deck.

"So, we carried her home, phoned the vets and took her straight round."

The 52-year-old retired firefighter took Chilli to Chess Veterinary Clinic, in Uxbridge Road, Rickmansworth, where she had her stomach pumped and was put on a drip.

Mr Stainer said the whole experience happened so quickly and that he was shocked at how suddenly his pet’s health declined.

He explained: "After she collapsed she began panting very heavily and she looked as though she might start to be having a seizure. She was deteriorating rapidly and within five minutes she had really gone downhill."

Chilli stayed at the clinic for five hours to receive treatment. Mr Stainer said she was still unwell for the next two days and has now recovered.

Mr Stainer said he wants to warn other dog owners of the threat to their pets on Chorleywood Common.

Kevin Snow, spokesman for Three Rivers District Council, said they have not heard of any other reports of dog poisonings in the area.

Mr Stainer added: "I really don’t know what it was that Chilli ate and all the vet could say was that she had consumed a toxic substance.

"From now on, sadly, we may have to keep her on a lead as this was a worrying experience that we don’t want to repeat.

"I think we were lucky as she is a fairly fit, medium-sized dog and was treated very, very quickly. Had she been smaller I feel the outcome may well have been very different. I feel it’s important to warn other dog owners of the possible danger to their pets on Chorleywood Common."

Staff at the Chess Veterinary Clinic said they were unable to comment on the Schnauzer's case due to "client confidentiality".