As with most pet medications there are possible side effects with Anipryl for dogs, that is why, it is ideal to follow your veterinarian's instructions precisely. Also, immediately report any signs of potential complications including: Vomiting, Diarrhea, Disorientation, Seizures, Hyperactivity, Hair loss, Shaking There can also be side effects of consuming Anipryl with other medications or pet health products including preventive tick collars and the incontinence drug phenylpropanolamine. In order to avoid that, give your vet a complete list of all the health products consumed by your pet. Selegiline is not to be consumed by animals with known hypersensitivity or allergy to the drug.