i have a 7 yr. spayed Lab that has had thyroid problems her whole life. She developed seizures also and after a couple years of these seizures (grand malls) I took her off of all meds. For 10 months she had NO seizures yet continued to be more lethargic and developed more joint problems and weight increased. I recently put her back on Soloxine and immediately she started scratching and chewing until she was bleeding. I changed her medication to Synthroid and still the same resutls. I don't know what to do at this point. She must be allergic to something in these pills. She must take thyroid medication! Please help if anyone has any suggestions.