Hypothyroidism - Sewickley Veterinary Hospital - Sewickley, PA

Sewickley Veterinary Hospital

1104 Ohio River Blvd.
Sewickley, PA 15143



Hypothyroidism in Dogs

Hypothyroidism is a condition resulting from a lowered production and release of T4 and T3 hormones by the thyroid gland.  The leading causes of this disease range from congenital disease, iodine deficiency, cancer, or can be of unknown etiology (origin).It is common in medium to large breed dogs, with some breeds being more predisposed than others.  These breeds can include Doberman Pinschers, Irish Setters, Golden Retrievers, Labrador Retrievers, Great Danes, Old English Sheepdogs, Dachshunds, Miniature Schnauzers, Boxers, Poodles, and Cocker Spaniels.  It is also more commonly diagnosed in middle-aged dogs between the ages of 4-10 years.



  • Lethargy
  • Generalized weakness
  • Inactivity
  • Mental dullness
  • Unexplained weight gain, or inability to lose weight
  • Alopecia (hair loss)
  • Excessive shedding
  • Poor coat quality
  • Excessively scaly skin


The veterinarian will use the history and current physical exams as well as the background history of symptoms to determine if thyroid testing is required.

Finding the exact cause of hypothyroidism may require a thorough investigation.  Routine laboratory testing will include a complete blood cell count, blood chemistry profile, urinalysis, and, importantly, endocrine testing.  The levels of the hormones T3, T4, and TSH will be measured to determine if these are on the lower than normal ranges.

The treatment of hypothyroidism is usually life-long with careful administration of medications and diet, as well as routine lab work and physical exams. The deficient hormones are given in a synthetic form (oral tablets) with the dosage based on your dog?s individual physical exam, lab results, and progress. Diet modifications, including a reduction in fat and routine exercise are also recommended throughout treatment.  Most symptoms will resolve within a few months of starting treatment.  However, routine exams and laboratory work will be necessary to determine whether the dosage should be adjusted.

Conscientious compliance with the medications and diet are a crucial part in the treatment of hypothyroidism.  To avoid complicating the condition, do not change the type or dosage of the drug yourself and never give anything new to your dog, including herbal remedies, without first consulting the veterinarian.