Animal owners are being urged to closely supervise their dogs after a number of pets were suspected to have ingested discarded marijuana on walks on Queensland's Sunshine Coast.
Marijuana is toxic to dogs and in some cases can be fatal if untreated.
Dog owner Chris Paulsen said the experience with her dog had been "terrifying".
"Teddy vomited a dark brown liquid and was very wobbly and struggled to stand," Ms Paulsen said.
"He had very little saliva and looked dazed and confused."
Ms Paulsen had taken Teddy for a walk at Bokarina Beach, north of Caloundra.
"Because his legs were unstable we assumed he had a tick," she said.
"By the time he got to the vet, he was incontinent."
The nine-year-old dog was treated with charcoal to remove the substance from his system.
"The vet bill was $500," Ms Paulsen said.
Public holiday peak
Emergency veterinarian Whitney Hansen said the occurrence was quite common on the Sunshine Coast, particularly after weekends and holiday periods.
"On Anzac Day we saw three consults in the one day and all three of them were highly suspicious of marijuana toxicity after the dogs had been to the dog park," Dr Hansen said.
"It can be really harmful.
"They're definitely a lot more sensitive to the drug than people."
Dr Hansen said symptoms included dilated pupils, a low heart rate, poor movement, and incontinence.
"They can actually slip into a coma and, in severe cases, they can suffer organ dysfunction and their body can shut down," she said.
Dr Hansen said if owners suspected their dog had eaten the drug, the dog should be taken to the vet for expert treatment and support.
"I wouldn't recommend trying to make them vomit at home," she said.
"These dogs are still high, so they are often quite sensitive to noises and sharp movements, so we like to keep them in a really dark, quiet, warm environment so that they're comfortable and they're not scared while they ride out there.
"As long as they receive the supportive care that they need, then once they are recovered, there shouldn't be any long-term effects."
Still not herself
Dog owner Rebecca Hann Patterson said her dog had not fully recovered since ingesting marijuana on a walk at Bokarina Beach in February.
"She was on a drip for nearly eight hours to rehydrate her and just monitoring her," Ms Patterson said.
"She was completely unresponsive and couldn't lift her head off the ground. She was really uncoordinated.
"We were scared that she was going to die."
Ms Hann Patterson suspected her dog ingested the drug after it had been stashed in the park by young people.
She urged authorities to take action to make the area safe.
"It's not fair on the dogs, it's not fair on the residents, and she's 11 years old now so she can't really take too many hits to her system," she said.
The Queensland Police Service has been contacted for comment.
