Most human studies of CBD have been done on people who have seizures, and the FDA recently approved the first CBD-based drug, Epidiolex, for rare forms of epilepsy. Clinical trials for other conditions are promising, but tiny. In one Brazilian study published in 2011 of people with generalized social anxiety disorder, for example, taking a 600-mg dose of CBD (higher than a typical dose from a tincture) lessened discomfort more than a placebo, but only a dozen people were given the pill.
It depends on your pet and the medicine being used. There have been many examples of dogs being more receptive to PurCBD than traditional medications, especially with anti-seizure, anti-inflammatory, and anti-anxiety medications. Always check with your veterinarian before starting, stopping, or adjusting the dosage of any prescription medication. Many drugs, especially anti-seizure medications, must be weaned off slowly or else deadly withdrawal symptoms can occur.