A Dose Finding Study of Cannabidiol in Dogs with Idiopathic Epilepsy

Affecting approximately 5% of the canine population, idiopathic epilepsy is a widespread disease that is often frustrating and, at times, devastating to both dogs and their owners. About one third of dogs afflicted by idiopathic epilepsy are refractory to the standard drugs available to treat the disease. Therefore, finding an effective replacement or adjunctive medication is imperative. Recently, the anticonvulsive properties of cannabidiol (CBD) have been demonstrated in human and canine patients. Although there are pilot data to support its use in our veterinary patients, to date, a true dose finding study has not been performed. The primary objective of this study is to find an effective dose of CBD for idiopathic epilepsy in client-owned dogs with uncontrolled seizures (≥2 seizures per month) secondary to idiopathic epilepsy. Aim 1 of this study is to determine the dose of oral CBD that will reduce average monthly seizure activity in client-owned refractory idiopathic epileptic dogs by 50% or more when added to standard anticonvulsive therapy. Aim 2 of this study is to evaluate the safety and tolerability of CBD in dogs with idiopathic epilepsy. We hypothesize that, at the appropriate dose, CBD will be effective in lowering the average monthly seizure frequency by 50% in at least 50% of uncontrolled idiopathic epileptic dogs and that CBD, even at high doses (up to 40 mg/kg/day), will be well tolerated.

Participation Requirements

In order to qualify for the study, dogs will have to meet the following criteria:

• Dogs with idiopathic epilepsy suffering from ≥ 2 generalized seizures per month for at least 12 weeks after being treated with adequate doses of at least one conventional AED are eligible for trial entry.

All dogs will undergo a complete seizure workup, including a neurological examination, bloodwork (CBC, chemistry panel, and bile acids if indicated), MRI of the brain, and CSF analysis (including infectious disease testing if indicated). Dogs will be excluded from the study if a systemic or structural lesion is found to be the cause of the seizures. An AED serum drug level will be performed at the time of enrollment. All dogs will have a “Time 0” CBD level drawn prior to enrollment to ensure no previous CBD administration has occurred. If a patient’s CBD concentration indicates previous exposure, the dog will undergo a four week “washout” and have their level retested. No dog will be eligible for enrollment if there is ongoing CBD administration.

Other specific exclusion criteria:

• Owner unable to follow proposed rechecks/treatments
• Owner unwilling to keep a seizure log
• Dogs with liver enzyme elevations greater than double the high end of the reported range and an abnormal bile acid test
• Comorbidity with a poor prognosis, especially active immune-mediated disease, infectious disease or neoplasia

Owner's Responsibilities

The study (per dog) is 3 months long.  The patient will need a recheck examination and blood draw every 4 weeks (total of 4 visits).  All costs associated with the study will be covered in full.

It is helpful to live in the state of Colorado.  However, investigators are able to work with clients from out of state, as long as they are willing to travel once to Colorado to pick up supplies.  In these cases (as well as cases from a long distance even within the state of Colorado), we are able to work with local veterinarians to obtain samples.

If you’re interested in enrolling your dog in this study please complete the qualification survey.