Drugged dogs being brought in for treatment – including in one case a chihuahua high on marijuana – are worrying Hamilton vets.

Veterinarian Julie Lavis said the tiny canine nearly died from hypothermia when it was brought in to the After Hours Veterinary Hospital in Hamilton scared and "in a bad way".

Roaches [the butts of cannabis joints] had been regularly left on a coffee table and the chihuahua had developed a fetish for eating them – and loved the taste of cannabis.

"[Marijuana] makes all the blood vessels dilate a bit and that's why they get red eyes," Dr Lavis said.

"So when those vessels are dilated they lose temperature – it's not bad if you're 40kg but when you're less than two, the poor thing was really cold. So we had to warm him up."

The team on the corner of Anglesea and Liverpool streets treats about one cannabis admission a fortnight.

Treatment consists of inserting a drip for hydration and a highly absorbent charcoal solution taken orally every four to six hours.

Symptoms include red eyes, poor motor function, irregular heart beat and poor temperature regulation.

It's "quite strange behaviour", Dr Lavis said.

In another case, a fluffy white wheaten terrier consumed some cannabis-laced "lolly cake" that had been thrown to the chickens during a clean out in preparation for a parental visit.

The animal was "relaxing back" smiling when it arrived at the animal hospital.

Another dog strayed from its owner and when the animal was found it was wobbling around the street. Initially, the upset owner thought it had been kicked or run over, but pot was to blame.

"I gather quite a lot of people put them in chocolate cookies, which is pretty tempting for a dog. We get a lot of dogs that are dust bins – they will eat anything."

Dr Lavis came to New Zealand five years ago from Britain. While practising there she only come across two cases of drugged dogs – she believes one was under the influence of cannabis and the other an opiate.

Fortunately, there were no long term side effects for the stoned dogs.

"You do not want to be giving this to your pets just to see what it does, because you can kill them with it," Dr Lavis said.

"And they can be really poorly through temperature regulation, heart going too fast or slow. It's not pleasant for them to not be in control of themselves and have this altered behaviour."

By far the most common form of dog poisoning was rat bait; one Sunday the hospital admitted eight cases.

Raisins, grapes and chocolate are other potential threats to hounds.

Consumption of the small berry can result in vomiting and elevated levels of calcium in the blood that can lead to kidney failure.

Chocolate, especially with a high cocoa content, contains theobromine that can disrupt heart function and cause death.

Dr Lavis's advice is to keep an eye on where dogs are at all times and when they are not being watched, keep them secure.

CANNABIS POISONING

Red eyes

Poor motor function

Irregular heart beat

Poor temperature regulation.

- © Fairfax NZ News