Medical Mystery: What caused a healthy dog’s seizure-like symptoms?

A worried owner called my veterinary clinic shortly before 8 a.m. one Saturday morning. Upon waking, she had found her previously healthy, six-year-old, female, Italian greyhound surrounded by puddles of urine and vomit.

The dog was shaking and unable to stand. She thought maybe the dog was having seizures or a stroke. I told her to bring the dog into the clinic for evaluation.

A physical exam revealed the dog was having small tremors, ataxia (difficulty standing and walking), urinary incontinence, dilated pupils, low heart rate, and a lower than normal body temperature.

The dog was showing clear signs of a neurological problem, but the symptoms didn’t quite match with a seizure as the owner first suspected.

Seizures typically last two to three minutes. In that time, pets having a seizure may have convulsions, urinate, lose bowel control, vomit, and lose consciousness. But seizures are usually discrete episodes, meaning once a seizure ends, the neurological symptoms generally go away.

But more than two hours after the dog’s owner found her, the dog was still twitching and trembling uncontrollably, and her hind legs collapsed every time she tried to stand. The dog also seemed very agitated and she continuously dribbled urine.

Tremors in dogs can have various causes, including low body temperature, low blood glucose, toxin and drug side effects, electrolyte imbalances, immune-mediated disease, and pain.

A key question I asked the dog’s owner illuminated the cause of the tremors.

After examining the dog, I asked the owner delicately, “Is there any possibility that your dog could have eaten marijuana?”

The owner thought for a second, then shook her head vigorously, “yes.”

She said a visiting family member had brought marijuana into the house. The door to the guest’s bedroom had been left open and the owner recalled that she had found the curious pup sniffing around the guest’s bag the previous night.

There are many toxins that can cause signs such as trembling and loss of control over bodily movements, but the constant dribbling of urine tipped me off that the patient had ingested marijuana. Prolonged urinary incontinence is often the telltale clue to marijuana poisoning.

Marijuana can be toxic to a number of animals, including dogs, cats, and even horses. In 2019, the ASPCA’s Animal Poison Control Center noted a large increase in calls about marijuana ingestion in pets. This likely reflects greater access to the drug due to a growing number of states legalizing marijuana. According to the ASPCA, marijuana edibles can be especially enticing to dogs because they often smell and taste like regular baked goods. Cats, on the other hand, are often more attracted to marijuana in its bud form.

Signs of marijuana poisoning can include trembling, loss of coordination, glassy-eyed appearance, sleepiness or excitedness, vomiting, dilated pupils, and urinary incontinence.

Signs generally can appear within an hour of ingestion. If a pet owner witnesses a dog eating marijuana, it is a good idea to induce vomiting with hydrogen peroxide to limit absorption of the drug.

While most pets will recover from marijuana toxicity on their own, it’s best to get your pet checked by your vet to rule out a more serious medical condition — especially if you think the pet may have consumed edibles (which could contain other harmful ingredients). Fortunately, death from marijuana toxicity is rare. However, synthetic cannabinoids can be much more potent and can cause more severe clinical signs. Ingestion of these products requires immediate medical attention.

Treatment for marijuana ingestion in dogs generally involves supportive care. Intravenous fluids to prevent dehydration, and anti-nausea medicine for vomiting are the mainstays of treatment. I sent the dog home after a course of fluids and anti-nausea medicine and her owner reported that the dog was feeling better the next day.

Scott Neabore is a veterinarian and the owner of Neabore Veterinary Clinic in Haddonfield.