what does weed do to dogs

What Does Weed Do to Dogs? Everything You Need to Know

As controversial as it may seem, we simply cannot ignore the fact that cannabis or weed has had a significant impact in the way various cultures around the world managed their health care problems or even as a means to divination. With evidence showing the use of weed dating as far back as 2,200 BCE, although the earliest known ‘intact proof’ of tetrahydrocannabinol was discovered about 2,700 years ago, it is clear why it has a considerable following even in scientific circles, creating a divide between those who want to use its medicinal properties to the fullest and those who invoke the right of everyone to be free from the ill effects of the psychoactive substance.

We understand some folks will benefit from the exclusive medical use of marijuana. The substance can reduce the severity of nausea and vomiting, enabling patients to last through their chemotherapy treatments where nausea and vomiting are common side effects. It’s beneficial for improving the appetite of individuals with HIV infection or AIDS since it increases hunger sensations, enabling the patient to eat with more gusto. It has also been used in the management of chronic pain as well as muscle spasms by affecting cannabinoid receptors in the brain.

But are these enough to justify the use of weed on dogs, too? While your dog simply won’t have a say about the legal status of marijuana in this country, you can nevertheless, equip yourself with the right knowledge about what weed does to dogs. This is the purpose of this article: to help you gain a better understanding about what weed does to your canine friend.

dog smelling weed

What Is the Effect of Marijuana on Dogs?

A review of the mechanism of action of tetrahydrocannabinol, the active ingredient found in cannabis or marijuana, reveals that it primarily affects cannabinoid receptors that are present in the brain. We need to appreciate that there are two principal types of cannabinoid receptors, although scientists posit that there could be many more.

The reason why we need to understand the physiologic action of tetrahydrocannabinol in human physiology is because there simply aren’t enough clinical data to support the physiologic mechanisms seen in dogs. As such, we can only make estimated guesses as to the clinical effects of marijuana on dogs.

As we were saying, there are two primary cannabinoid receptors. One, CB1 is found in almost all tissues of the body but is greatly concentrated in the brain. This receptor type is also found in the lungs, kidneys, and liver. The other type, CB2, is mostly found in the cells of the immune and hematopoietic systems.

Cannabinoid receptors are responsible for the sensation of pain, appetite, memory, mood, coordinated movement, thought, time and depth perception, and concentration. Tetrahydrocannabinol binds to these receptors which lead to an interference in their normal functioning.

According to experts, the following manifestations are typically the effects of marijuana on dogs.

  • Lethargy
  • Signs of paranoia: pacing and panting
  • Breathing problems
  • Low blood pressure
  • Loss of balance
  • Abnormal heart rhythm
  • Urinary incontinence

These effects are the result of the action of tetrahydrocannabinol on the cannabinoid receptors. For instance, its effects on the cerebellum can lead to loss of a dog’s ability to coordinate the movement of its 4 limbs in relation to the movement of the rest of its body. This part of the brain is also important in maintaining posture and balance such that it becomes quite easy to see if a dog is “high” on weed or not.

While there have been no tests conducted on dogs to study the effects of marijuana on their memory formation, we can only surmise that the physiologic effects will be a lot similar to humans. Marijuana is known to negatively impact short term memory as well as the creation of new learning. That said, it may be quite difficult to train a dog that is presently ‘high’ on weed. The good news is that the cessation of marijuana consumption has been shown to lead to memory recovery. We can at least feel confident that our dogs’ capacity for learning will still returns to normal, allowing us to train them.

Sensory perception is also affected by weed or marijuana. Alterations in sensory perception can lead to accidents since sensory stimuli are not correctly processed by their respective integrating centers in the brain.

Additionally, since tetrahydrocannabinol also affects the hypothalamic region of the brain, this can lead to a host of problems in respirations and in cardiovascular functioning. That is why you may see dogs that are ‘high’ on marijuana that manifest breathing problems. There can also be irregular heart rhythm which can be further complicated by a reduction in overall systemic blood pressure. All of these events can undermine the efficient delivery of oxygen to the tissues leading to hypoxia and ischemia. Since all tissues require oxygen for optimum functioning, a reduction in the delivery of oxygen can undermine these functions.

Irregular heart rhythm simply means the heart is not pumping blood at an optimum rate. The amount of blood pumped by the heart with each beat is dependent on the full relaxation of the heart prior to each beat. This allows the heart to be filled with blood. If the heart cannot fully relax in between heart beats, the chambers of the heart will not completely fill with blood. The next time the heart contracts it will only be ejecting blood less than its normal capacity. So, the amount of blood received by the various tissues of the body will also be less than the normal.

Low blood pressure also has an effect on tissue oxygenation since this is the pressure needed on the walls of the arteries to push the blood forward. If the pressure is too low, even if you have adequate amount of blood from the heart, then too little blood will reach the tissues.

Likewise, issues in respirations can lead to oxygenation problems since it is through the lungs that outside air is filtered and allowed to diffuse into the blood. It is also through the lungs that metabolic byproducts such as carbon dioxide are eliminated.

As for the psychotropic effects of cannabis on dogs, there really is no clear-cut evidence showing the thought patterns of canines after exposure to cannabis. Experts can only rely on observable behavioral changes in dogs to somehow make estimates as to whether dogs also suffer from the psychotropic effects of weed or not.

It is also critical to understand that your dog’s size can also determine the severity and extent of the effects of cannabis. Generally, extremes of age will be more susceptible to the various effects of cannabis than breeds of the adult stages. Elderly dogs, while they are larger than puppies, often present with preexisting medical conditions brought about by aging. These can be exacerbated by the physiologic effects of marijuana.

benefits of weed for dogs

How Does My Pooch Get “High” on Weed?

As we have already mentioned, it is not really easy to tell if a dog is ‘high’ or not. The two signs interpreted by many as potentially related to the psychotropic effects of cannabis: panting and pacing, are not behaviors that are exclusive to cannabis consumption. Dogs pant if they are experiencing extreme heat. Dogs pace if they are anxious, feel threatened, or even when under stress. The point is that there are many other reasons why a dog may pant and pace other than having consumed weed.

As such, one of the ways we can associate these behaviors to being ‘high’ on marijuana is if we have observed our dogs to have been exposed to such substances. But how do dogs get ‘high’ on weed? Experts say there are 3 fundamental methods in which dogs can get exposed to and get high on weed. These include the following.

  1. Direct ingestion of the leaves or buds of marijuana.
  2. Ingestion of food items like butter and cookies that have been laced or mixed with cannabis.
  3. Exposure to secondhand marijuana smoke.

Is Cannabis Bad for Pet Dogs?

It is clear that some dogs may actually benefit from the use of cannabis with some owners reporting longer lifespans for their respective pooches. Unfortunately, as we have already pointed above, there really isn’t much to go about establishing with absolute certainty the clinical usefulness of marijuana in canine applications. While the mountain of evidence does support its limited use in certain segments of the human population, with everyone clearly divided, there are a lot of questions left unanswered as to the effects of cannabis on dogs. We can only assume that marijuana is not safe for dogs to consume or even be exposed to such substances.

Is Marijuana Toxic or Poisonous to Canine Pets?

Experts agree that marijuana poisoning is a huge threat to the safety and integrity of pooches. While some of the physiologic effects of cannabis toxicity in dogs can be considered as moderate, a greater number of these physiologic effects are known to be severe. This is especially true in cases where the dog has ingested substantial amounts of marijuana. This can lead to life threatening effects that warrant a prompt visit to your veterinarian if not an emergency veterinary care facility.

Here we have listed some of the moderately severe signs and symptoms of marijuana toxicity that you may have to be wary of.

  • Walks like a drunk; unsteady, shuffling gait
  • Hyperactivity, restlessness
  • Increased vocalization
  • Lethargy, weakness
  • Severe depression

The following are considered to be severe effects of marijuana toxicity such that any of these

should already prompt you to consult with your vet.

  • Dilated pupils
  • Unusually slow heart rate
  • Respiratory depression
  • Low blood pressure
  • Seizures
  • Coma

Pupillary dilation is often a sign of a decreasing level of consciousness. We can always think of it as a sign of impending demise since the higher cortical controls are simply not integrating signals coming from the oculomotor nerve. This can be the result of seizures which significantly increases the length of time brain cells are not receiving oxygen. The longer the seizure the longer are cells unable to obtain oxygen from the blood. This leads to hypoxic changes in the brain leading to a loss of function of the regions of the brain that did not receive ample supply of oxygen. This leads to erratic changes in the heart rate with corresponding depression of the respiratory center in the pons and the medulla oblongata. If not managed immediately and decisively, your dog may end up losing its life.

dog running in grass

Is it Okay to Give Medical Cannabis to Dogs?

There is an increasing number of US states that are legalizing the use of cannabis both for recreational and medical purposes. Unfortunately, these only cover marijuana use in the human population, not dogs. And while it is easy to understand why some pet owners actively give their dogs cannabis for a variety of health conditions such as:

There really is no way we can establish with absolute certainty that these observed ‘therapeutic effects’ are attributable to the administration of medical marijuana in dogs. There simply is no research that has provided a foolproof analysis of the inferential relationship between medical marijuana and the mitigation if not elimination of these clinical symptoms.

It is understandable that pot shops have now begun catering to the pets of dog owners as well, citing the benefits that human medical cannabis users have enjoyed for quite some time now. It is hoped that dogs will also respond in the same way as humans.

Regrettably, while dogs are our best friends, their anatomy and physiology vaguely differ from ours. Even if the difference is minute, this can still have an effect that is totally different from the ones that we have seen people using medical cannabis experience. As such, even if the cannabis is intended for veterinary medical purposes, we really cannot recommend its use for the simple fact that we don’t know enough to warrant making a credible decision. We need more conclusive evidence to support its use on dogs. More specifically, we need empirical studies conducted on dogs themselves and not on humans.

If you are looking to give cannabis to your dog, you may wish to read our review of the best cbd oil for dogs as using hemp oil is a great way to supplement your dog’s diet.

Related Post: CBD Oil for Dogs


  1. Amy Young, Marijuana Toxicosis, UC Davis
  2. Laura Klivans, Legal Weed Is A Danger To Dogs. Here’s How To Know If Your Pup Got Into Pot, NPR

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