Hypothyroidism in Dogs

Hypothyroidism in Dogs

By: Dr. Bari Spielman

Section: Overview

What To Watch For

A deficiency of thyroid hormone affects the metabolic function of many organ systems. As a result, the clinical signs are usually variable, non-specific, and slow to develop. Although there is no one symptom that is diagnostic, several combined signs may make your veterinarian more suspicious. Symptoms may include:

  • Lethargy, lack of interest in play, increased amounts of sleeping
  • Depression, mental dullness
  • Exercise intolerance (tires easily)
  • Weight gain (without an apparent increase in appetite) and obesity
  • Cold intolerance – seeks out warm places to lie down, low body temperature
  • Slow heart rate (bradycardia)
  • Infertility
  • Constipation
  • Diarrhea
  • Chronic skin disorders, such as dry skin, thinning of the hair coat, excessive hair loss
  • Possibly other neurologic signs
  • Possibly other hormonal abnormalities

    Diagnosis


    Hypothyroidism is not always a simple, straightforward disease to diagnose. Various tests are available to diagnose the condition and a combination of tests may be required. Proper diagnosis also includes a thorough history, documentation of clinical signs, a thorough physical examination, and diagnostic tests to assess various organ functions, including thyroid function. A diagnostic work-up may include the following:

  • Complete blood count (CBC)
  • Biochemical profile
  • Urinalysis
  • Thyroxine (T4) level, free-T4 level
  • Canine TSH test
  • Thoracic (chest) and abdominal radiographs (X-rays) in certain cases

    Treatment

    Fortunately, hypothyroidism is easily treated and involves the administration of daily doses of synthetic thyroxine. Once treatment is started, it must usually be continued for the rest of the dog's life.

    At Home

    At home, administer all prescribed medication(s) and observe your dog closely for recurrence or improvement in the clinical signs. Overdosage with thyroid medication causes signs of hyperactivity and weight loss. Your veterinarian may schedule periodic blood tests to measure the levels of thyroid hormone in order to monitor whether the dosage being given is adequate.

    Prevention

    There are no effective ways to prevent hypothyroidism. However, once treatment begins, many symptoms resolve within several weeks.

    •  
    Printable Version
     
    Have a Pet Question?
    Review the Most Frequent Questions
    Answered by Dr. Jon and His Staff of Veterinarians
    Ask Dr. Jon
    Dr. Jon's Newsletter
    Yes! Send Me the Latest Health Information, Pet Tips, Pet Stories and more...
     
     

    Related Articles

    • 1 Obesity in Dogs

      The primary causes of obesity in dogs are overeating and lack of exercise. When regular caloric intake exceeds the energy burned, the excess is stored as fat on your dog.

      Read MoreRead More
    • 2 Skin Discharge or Odor in Dogs

      Skin odor is a common manifestation of a skin infection; the most common skin infections are bacterial (superficial pyoderma) and yeast (Malassezia dermatitis) infections.

      Read MoreRead More
    • 3 Seborrhea in Dogs

      Seborrhea or scaly skin is common in dogs and is more a symptom than a disease. Seborrhea can be dry (seborrhea secca) or oily (seborrhea oleosa), and different dog shampoos are used according to the type...

      Read MoreRead More
    • 4 Alopecia (Hair loss) in Dogs

      Alopecia is the complete or partial lack of hair in any area of the skin where hair would normally be found. In dogs, it may be caused by self-trauma, hair follicle diseases or the failure of hair to grow...

      Read MoreRead More
    • 5 Thyroid Test in Dogs

      A thyroid test is a blood test to evaluate the function of the thyroid gland, which produces thyroid hormone, an important hormone in the regulation and maintenance of body functions.

      Read MoreRead More
    Related Articles
    • 1Alopecia (Hair loss) in Dogs

      Alopecia is the complete or partial lack of hair in any area of the skin where hair would normally be found. In dogs, it may be caused by self-trauma, hair follicle diseases or the failure of hair to grow...

      Read MoreRead More
    • 2Obesity in Dogs

      The primary causes of obesity in dogs are overeating and lack of exercise. When regular caloric intake exceeds the energy burned, the excess is stored as fat on your dog.

      Read MoreRead More
    • 3Seborrhea in Dogs

      Seborrhea or scaly skin is common in dogs and is more a symptom than a disease. Seborrhea can be dry (seborrhea secca) or oily (seborrhea oleosa), and different dog shampoos are used according to the type...

      Read MoreRead More
    • 4Skin Discharge or Odor in Dogs

      Skin odor is a common manifestation of a skin infection; the most common skin infections are bacterial (superficial pyoderma) and yeast (Malassezia dermatitis) infections.

      Read MoreRead More
    • 5Thyroid Test in Dogs

      A thyroid test is a blood test to evaluate the function of the thyroid gland, which produces thyroid hormone, an important hormone in the regulation and maintenance of body functions.

      Read MoreRead More
     

    Over 10,000 Veterinarian Approved Articles

    Dogs & Puppies
    Cats
    Related Articles
    • 1Alopecia (Hair loss) in Dogs

      Alopecia is the complete or partial lack of hair in any area of the skin where hair would normally be found. In dogs, it may be caused by self-trauma, hair follicle diseases or the failure of hair to grow...

      Read MoreRead More
    • 2Obesity in Dogs

      The primary causes of obesity in dogs are overeating and lack of exercise. When regular caloric intake exceeds the energy burned, the excess is stored as fat on your dog.

      Read MoreRead More
    • 3Seborrhea in Dogs

      Seborrhea or scaly skin is common in dogs and is more a symptom than a disease. Seborrhea can be dry (seborrhea secca) or oily (seborrhea oleosa), and different dog shampoos are used according to the type...

      Read MoreRead More
    • 4Skin Discharge or Odor in Dogs

      Skin odor is a common manifestation of a skin infection; the most common skin infections are bacterial (superficial pyoderma) and yeast (Malassezia dermatitis) infections.

      Read MoreRead More
    • 5Thyroid Test in Dogs

      A thyroid test is a blood test to evaluate the function of the thyroid gland, which produces thyroid hormone, an important hormone in the regulation and maintenance of body functions.

      Read MoreRead More