Dogs can experience side effects, such as vomiting and diarrhea, following a de-worming treatment. Some dogs experience muscle twitching or seizures after being treated for worms. Expect to follow up with additional de-worming treatments, such as a monthly preventative medication, throughout the dog's life.
In some cases, dogs can be poisoned by the toxicity of worm medication. This occurs when the dog is already severely weakened from the worm infestation. Puppies that are improperly weaned or suffer from respiratory disease are at a higher risk for side effects. Consult a veterinarian prior to giving any dog de-worming treatments. Treatments are available to dogs in both liquid and tablet forms.