These medications are initially prescribed according to the cat's weight. Once thyroid hormone levels have stabilized within a normal range, your veterinarian will likely check the levels every six months to year. Once treatment begins, most hypothyroid cats are increasingly active and show fewer behavior problems within a week. Hair growth typically accelerates in about a week, too, although bare spots may take months to fully grow in. Most cats begin to lose excess weight within 2-4 weeks of starting treatment.
Some veterinarians also suspect a link between behavior problems and hypothyroidism.
Increased aggression is the most commonly suspected behavior change, but some veterinarians speculate that a few hypothyroid cats may develop anxiety related or compulsive behaviors. If your pet develops a sudden behavioral change, have your cat's thyroid status examined. While all owners should be on the lookout for changes in their cat s appearance or behavior that suggest hypothyroidism, owners of middle-aged and elderly cats should be especially watchful. If you notice any signs, consult your veterinarian. By simply taking a sample of your cat s blood, it can be determined if the cat has hypothyroidism.