I have noticed that the first time I gave my Stella heart guard plus she started having head tremors within hours of ingestion. I stopped the medication for the winter months and no tremors. I then recently started her on them again and she has started the head tremors again. I read the side affects of the medication are seizures/tremors. Has anyone else had this problem? I’m looking for alternatives to heart worm prevention now. Thank you Bulldog lovers!