Tech Talks by Emily Harbury. LVT
Marijuana has been used in Washington State for many years and is legally available in numerous locations in our Valley. As use of marijuana becomes common, the number of pets, particularly dogs, showing up in our clinic after exposure to THC has increased dramatically. The good news is that marijuana toxicity is seldom fatal and your vet may be able to reduce the effects for your dog; the bad news is that if you aren’t SURE that it is marijuana, and only marijuana, that your dog has ingested the symptoms are very similar to much more harmful toxins that need immediate veterinary intervention if your dog is to survive.
Owners are sometimes hesitant to tell the veterinarian that their dog has eaten marijuana, but their hesitance can slow and complicate diagnosis and treatment. It is important for all relevant exposure information to be given to the veterinarian. Veterinary staff don’t care if the owner uses marijuana or if his neighbors have marijuana the dog got into. Veterinarians do not report marijuana ingestion to any legal authorities. They just want to know why the dog is exhibiting symptoms. The Vet needs information to come up with the best treatment plan. If you know marijuana was involved in an intoxication tell the attending doctor.
Marijuana toxicity can look similar to intoxication with numerous other sedatives, one of the most serious considerations is whether the dog has ingested antifreeze. In the early stages, a dog who has eaten antifreeze looks very similar to a dog who has eaten marijuana. But correct diagnosis is important because antifreeze consumption is usually fatal if not diagnosed and treated quickly.
The usual pet toxicity case involves a dog who has inadvertently eaten a stash of marijuana, trimmings from plants, or baked goods with marijuana butter used. In dogs, clinical signs typically begin 30 to 90 minutes after the marijuana has been eaten. Because THC is stored in the body’s fat deposits, the effects of marijuana ingestion can last for several days.
Signs include:
- incoordination and listlessness
- dilated pupils
- slow heart rate
- urinary incontinence
A characteristic startle reaction has been described where the pet appears drowsy and even may begin to fall over but then suddenly catches his balance.
If the owner doesn’t know what the dog ingested, or doesn’t tell the veterinary staff then testing must be done. Urine testing can diagnose marijuana as well as a number of other recreational drugs. A relatively large volume of urine is needed to run these tests. It can be difficult to collect an adequate sample from small, particularly small female, pets. Metabolites relevant to the test are different between dogs and humans. In dogs, false negative results are common; though a positive is confirmatory. In most cases, diagnosis is made based on the clinical presentation of the dog plus history of marijuana exposure.
If less than 30 minutes have passed since the marijuana has been eaten it may be possible to induce vomiting, but after symptoms have started the nausea control properties of cannabis make it difficult to induce vomiting. Furthermore if the patient is extremely sedated, vomiting can be dangerous as vomit can be inhaled and cause an aspiration pneumonia. Activated charcoal is a liquid material used in the treatment of poisoning.
Activated charcoal is given orally and as it passes from one end to the other, toxins are trapped in the charcoal so that when the charcoal passes from the patient, the toxins pass too. This technique of detoxification may be used to treat marijuana toxicity if ingestion has occurred recently. Fluid support and keeping the patient warm may also be needed. IF the patient has lost consciousness, then more intense observation and support is needed. The chance of fatality is statistically small but possible. In most cases, the patient can simply be confined to prevent injury until the THC wears off.