According to the Doctors Foster and Smith website, Heartgard also called Ivermectin is a heart worm medication for dogs. There are different types based on your pet's weight such as tablet or chewable.
Heartgard is a monthly treatment that is more of a preventative measure for heart worms. However, like all medications, Heartgard treatments may cause unpleasant side effects for some pets.
One of the most common side effects associated with Heartgard is digestive problems. Some dogs will experience nausea and vomiting along with diarrhea.
Check the dosage to be sure you didn't give your pet too much medication. If the dosage is correct and symptoms persist, talk to your vet about trying a different heart worm medicine.
Depression is another side effect noticed with Heartgard worm medicine. If your pet is depressed it will become lethargic and lose interest in normal daily activities.
The pet may lose its appetite and become very lazy. If this side effect continues, talk to your veterinarian.
Lack of Coordination
Lack of coordination is another side effect associated with Heartgard. If your dog begins running into walls or falling down more easily this is a sign that it is losing coordination skills. Try decreasing the dosage or ask your vet to try another medication.
A rare, but serious side effect of Heargard medicine is seizures. Your dog will begin having convulsions and move out around on the floor frantically. If your dog begins having a seizure, take him to an emergency animal clinic right away.