CBD and Dog Medications: Interactions to Know

CBD can interact with certain dog medications, mainly because both CBD and many common drugs are broken down by the same liver enzyme pathway, called cytochrome P450. When CBD competes with a medication for that pathway, the drug can build up in your dog's system at a higher level than intended, or clear out more slowly than expected. This matters most for medications with a narrow safety margin, like some seizure or heart medications, where getting the dose even slightly wrong has real consequences.

 

This isn't a reason to rule CBD out. It's a reason to loop your vet in before combining it with any prescription your dog is already on. For the fuller picture on CBD safety generally, see Is CBD Safe for Dogs? Evidence, Side Effects, and Vet Guidance.

 

 

The Short Answer: CBD Drug Interactions Dogs May Experience

Tell your veterinarian about every medication your dog receives before adding CBD. This includes phenobarbital, carprofen (and other NSAIDs), some heart medications, and sedatives. Your vet may monitor bloodwork or adjust timing to help both medications work as intended. 

Keep in mind, though, that direct evidence for each combination varies. The Preliminary In Vitro Evaluation of Metabolism and Drug-Drug Interactions of Cannabidiol and Cannabidiolic Acid in Dogs, for instance, identified possible effects on certain liver enzymes. However, the researchers noted that canine studies are still needed to confirm their clinical importance.

The controlled study, Drug-Drug Interaction Between Cannabidiol and Phenobarbital in Healthy Dogs, found no significant pharmacokinetic interaction. Still, your veterinarian may recommend bloodwork or a specific schedule based on your dog’s health.

Never start, stop, replace, or change a prescribed medication without veterinary direction. If your dog takes no other medications, an interaction is less likely. Even so, CBD can cause side effects and may interact with over-the-counter products or supplements. 

 

 

What It Depends On

The interaction potential depends on the medication, CBD amount, schedule, liver health, age, and overall wellness. A healthy adult Lab receiving a low dose of joint medication has different needs than a senior dog. A senior pup may have liver concerns or receive seizure medication with a narrow therapeutic window.

Timing may also play a role. Some veterinarians may suggest separating CBD and certain medications by a couple of hours. Still, canine evidence has not confirmed that spacing prevents a metabolic interaction. Follow your veterinarian’s exact instructions instead of changing the schedule yourself.

The CBD dosing chart for pets can provide general CBD guidance for that conversation. It does not replace an amount selected by your veterinarian.

Bloodwork can add another layer of safety. The Tolerability of Long-Term Cannabidiol Supplementation to Healthy Adult Dogs research found increased alkaline phosphatase activity. The finding did not indicate liver damage, but researchers recommended monitoring liver function during long-term use.

Your veterinarian may request a baseline liver panel before CBD. Another panel may follow a few weeks later, especially with phenobarbital. This does not necessarily mean something is wrong. It simply gives your vet information about how your dog is responding.

 

 

What to Do Next

Your vet decides the dose. Before adding CBD to any prescription medication, contact your veterinarian and mention both. Bring the exact pet-formulated product, ingredient list, concentration, and milligram strength. These details help your veterinarian evaluate the combination more accurately.

If approved, follow the amount and schedule your veterinarian provides. Watch your dog closely during the first week, even if they’ve used CBD before.

Keep a simple log for the first couple of weeks. Record:

• The dose given
• The time of day
• Each medication’s timing
• Anything helpful or unusual you notice

A written record can also make follow-up bloodwork discussions clearer. Contact your veterinarian if you notice unusual sleepiness, poor coordination, digestive upset, or other concerning changes.

After your veterinarian approves a product, browse our CBD Oil for Dogs collection. Its range of concentrations can support measured use under veterinary guidance.

 

 

Related Questions Owners Ask

You may also wonder whether your dog could become dependent on CBD over time. Is CBD Addictive for Dogs? explains what current evidence suggests.

Side effects can be harder to trace when your pup receives several medications. CBD Side Effects in Dogs: What's Normal, What's Not distinguishes mild reactions from more concerning signs.

 

 

Frequently Asked Questions

Can I give my dog CBD with Carprofen or other NSAIDs?

Only combine them with your veterinarian’s approval. Direct canine evidence of a CBD-carprofen interaction remains limited. However, your vet may consider liver health, other medications, and possible side effects. Bloodwork may also be recommended. Never add CBD or change carprofen without veterinary guidance. 

Does CBD interact with seizure medications like phenobarbital?

An interaction is possible, but canine evidence does not show that CBD consistently changes phenobarbital levels. One controlled study found no significant pharmacokinetic interaction in healthy dogs. That said, CBD may affect liver-enzyme readings. Dogs receiving seizure medication need veterinary guidance and may require bloodwork. 

Is it okay to give CBD and Gabapentin together?

Only your veterinarian can determine whether this combination is appropriate for your dog. Direct canine interaction research remains limited. Because both may cause sleepiness or poor coordination, using them together could intensify those effects. Never add CBD or change your dog’s gabapentin schedule without veterinary guidance. 

How do I know if my dog's medication is affected by CBD?

Ask your veterinarian, since outward signs may not reveal an interaction. Bring the CBD product, concentration, ingredient list, and complete medication list. Your vet can review the combination and your dog’s health history. Bloodwork or closer observation may be recommended when a potential interaction needs monitoring. 

If your veterinarian approves CBD, consider our Broad-Spectrum CBD Oil for Dogs for measured dropper servings. Browse our CBD Oil for Dogs collection to compare veterinarian-approved options.