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10 Possible Side Effects of CBD Oil in Dogs (Vet Answer)

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By Dr. Samantha Devine

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Dr. Samantha Devine

Veterinarian, DVM

The information is current and up-to-date in accordance with the latest veterinarian research.

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CBD. You’ve probably heard the buzzwords about yourself or your pets, with people touting the health benefits of this supplement. With its relation to marijuana, it’s no surprise that people are questioning what the possible side effects of CBD oil are. Are there any dangers you should know before giving it to your dog? Are there any side effects? In this article, we’ll discuss what CBD is and the possible side effects if you give it to your dog.

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What Is CBD?

CBD is short for cannabidiol. CBD oil is typically derived from the hemp plant, but it can also come from cannabis. Most CBD oil products have 0.3% or less of the psychoactive compounds that produce the effects that marijuana is known for.

CBD oil affects the endocannabinoid receptors in the body. People use it to treat numerous conditions, from seizures to anxiety, in dogs.

Photo Credit: Erin Stone, Pixabay

The 10 Potential Side Effects of CBD Oil in Dogs

We don’t know all about how CBD oil can affect dogs. We can draw some conclusions based on its use in people, but it’s not a regulated product. Your experiences can vary wildly based on your product, the dose you give your dog, and even your dog’s metabolism.

1. Lower Blood Pressure

When humans or dogs take CBD oil, the supplement can cause a drop in blood pressure, which is most likely with high doses. Unfortunately, it is hard to determine if your pup’s blood pressure is low without a trip to the vet for blood pressure monitoring.

Potential signs that your dog has low blood pressure include:

  • Weakness
  • Collapse
  • Dizziness
  • Pale gums
  • Elevated heart rate
pet dog taking cbd oil from owner
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2. Dizziness

Dizziness is possible for pups taking CBD oil. It can be related to lower blood pressure but also to other CBD oil effects on your dog’s body.

Your dog might not want to get up. They could also circle or have a head tilt. These can also relate to neurologic problems and are worth discussing with your vet. Discontinue the CBD in the meantime.

In some cases, CBD oil can have THC in it, which can be toxic to your dog and cause signs like dizziness. You’ll want to check your product for ingredients and, ideally, a certificate of the contents before administering any to your pup.

3. Sleepiness

If your dog is anything like my active pups, sometimes a little sleepiness seems like a good thing. In the short term, it could be helpful if you’re using CBD oil to help control anxiety related to events like thunderstorms or visitors coming over.

Some dogs experience marked lethargy when they’re taking CBD oil, but this could also be a symptom of other health issues. If your dog shows signs of lethargy, try discontinuing or lowering the CBD oil dose and see if it changes. If not, schedule a vet visit, particularly if your dog sleeps most of the day. Make sure to let them know that you’ve been giving your dog CBD oil.

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4. Tremors

While CBD oil is often used to treat neurological problems such as seizures, it can also cause neurologic changes. As noted with dizziness, you could see circling or a head tilt.

The good news is this sign isn’t anything common in dogs. It has just been reported in people, but it is crucial to keep it in mind as we extrapolate potential issues for our dogs.

5. Diarrhea

Any time we give supplements or medications, particularly when given by mouth, we can inadvertently cause gastrointestinal signs in our dog. Depending on what ingredients are in the CBD oil, your dog could react to it. The ingredients may also disrupt your dog’s gut microbiome, leading to diarrhea.

Consider trying a product with different flavoring before you eliminate it. If your dog has repeated diarrhea or vomiting, it is important to have it examined by your veterinarian, especially since other things, such as intestinal parasites, can cause gastrointestinal signs.

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6. Vomiting

Like diarrhea, vomiting is a potential side effect of CBD oil. It could be the ingredients or even the flavoring of the oil. Some companies offer a variety of flavors for dogs, so you could always look into other options. In addition to liquids, there are even chews and treats, so you’ve got options. If the vomiting continues, you’ll need to schedule a veterinary visit. If your dog might have eaten something out of the ordinary, make sure you contact your vet rather than just trying different CBD products.

7. Bloodwork Changes

Limited studies on CBD oil in dogs are available, particularly evaluating potential side effects. One study that evaluated how effective CBD oil was in treating dogs with arthritis examined blood work values to identify changes.1 After treatment, one liver enzyme, alkaline phosphatase, was elevated in some dogs.

This liver enzyme can become elevated from many different conditions and medications, so your vet will consider all factors in your dog’s health. Mild elevations aren’t necessarily cause for concern, and veterinarians will usually monitor for changes before more in-depth testing, such as an abdominal ultrasound.

dog taking CBD oil
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8. Drug Interactions

CBD oil can interfere with your dog’s metabolism of other medications (and other medications and supplements can interfere with how your dog metabolizes the CBD oil). CBD inhibits cytochrome P450, essential in metabolizing some medications, such as anti-seizure drugs. Your veterinarian needs to know if your dog is taking both to account for that and potentially make dose adjustments.

Some gastric medications, such as omeprazole and famotidine, can block the absorption of CBD oil (and other medications), so you’ll want to separate when you give these products.

9. Dry Mouth

Some dogs experience dry mouth when taking CBD oil. This sign might sound like a positive benefit if your dog is constantly drooling, but it’s not. Your dog’s saliva has important oral health benefits, including fighting plaque and helping break down food.

You might see your dog exhibit dry mouth by drinking more. If your dog is suddenly very thirsty after trying CBD oil, back down the dose or discontinue it. If the altered thirst persists, take your dog to the vet for a workup because diabetes and kidney disease can also cause increased thirst.

corgi dog drinking water
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10. Itchiness

Some dogs are allergic to CBD oil or other ingredients in the product, such as flavorings. Skin flare-ups or itchiness in your dog can indicate allergies. Other supplements, medications, food, and the environment can trigger these signs.

If your dog’s itching doesn’t stop when you pause the CBD oil, talk to your veterinarian. Untreated itchiness can lead to skin infections and may need to be treated with a variety of medications or products, including:

  • Shampoo
  • Conditioners
  • Steroids
  • Antibiotics
  • Antifungals
  • Apoquel
  • Cytopoint
  • Fish oil products

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Considerations With CBD Oil

An organic product is often your safest bet. These products should not have contaminants, such as pesticides or other chemicals that could be quite toxic for your dog.

Look for a high-quality product with a certificate stating how much CBD is contained. This way, you can better know precisely what you’re giving your dog. You might be paying more for a good product, but it’s more likely to be a safer option, with less chance of hazardous additives.

We don’t know all the potential effects of CBD oil, and because it isn’t an FDA-regulated product, we don’t know the perfect dose for pets. Start with a low dose and work your way up slowly.

Hemp CBD oil
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For many people, CBD oil has been a game-changer in how they treat their dogs. However, it has potential side effects, so it’s essential to consider these before starting your dog on the supplement and discuss possible options with your vet before starting a product.

Featured Image Credit: 24K-Production, Shutterstock

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