Vet Talks: Hypothyroidism in Dogs Vet Talks 3 min read
Hypothyroidism in dogs is one of the most common diseases I see at the Animal Wellness Clinic (my veterinary practice). A thorough understanding of the disease and the symptoms will help with early diagnosis and treatment.
Below is an explanation of the complicated and all encompassing disease of hypothyroidism in dogs.
What is hypothyroidism?
The thyroid gland is part of the endocrine system, a butterfly shaped gland located in the neck, just below the larynx and partially wrapped around the trachea. It secretes two major hormones, thyroxine (T4) and to a lesser degree, triiodothyronine (T3). When T4 is absorbed into tissue cells, it is converted into T3. Most of the circulating T4 is carried by blood proteins and is not available for tissue absorption, the portion that is not carried by proteins (free T4) is the portion able to enter tissues for activation.
Production of T4 is regulated by the pituitary gland at the base of the brain. The pituitary secretes a substance called TSH. When T4 levels are dropping, the pituitary gland stimulates the thyroid gland to make and release more T4. Virtually, every cell in the body can be affected by reduced levels of thyroid hormone.
Symptoms of Thyroid Disease in Dogs
Low thyroid levels lead to symptoms in multiple body systems. Below are some of the systems that are affected and symptoms pet parents should look out for:
Alterations in cellular metabolism, which can result in:
- Paralysis of the larynx or facial muscles
- Knuckling or dragging the feet
- Muscle wasting
- Head tilt and drooping eyelids
Neuromuscular problems, which can cause:
- Mental weakness
- Exercise intolerance
- Weight gain
- Cold intolerance
- Behavior changes
Dermatologic diseases that can be seen include:
- Dry, scaly skin (dandruff)
- Dull or coarse hair coat
- Symmetrical hair loss
- Darkening of the skin
- Greasy skin
- Frequent bacterial and yeast skin infections
- Chronic ear infections
Reproductive Disorders associated with low thyroid function include:
- Infertility and reproductive underdevelopment
Cardiac abnormalities seen with hypothyroidism include:
- A slow heart rate, abnormal heartbeats, and physical heart problems.
Gastrointestinal disorders seen include:
- Constipation, vomiting, or diarrhea
Hematological disorders seen with low thyroid may include:
- Uncontrolled or abnormal bleeding
- Failure of the bone marrow to produce cells
- Low white blood cells
- Low platelet numbers
Ocular diseases connected to hypothyroidism can include:
- Lipid deposits in the cornea
- Corneal ulceration
- Inflammation in eye
- Dry eye syndrome
Left untreated, any number of the above disorders or symptoms can dramatically shorten a dog’s life and certainly decreases their quality of life.
What causes hypothyroidism in dogs?
Genetics and autoimmune disease of the thyroid gland causes a predisposition for hypothyroidism. There are also many environmental factors, such as diet/nutrition and exposure to toxins or chemicals that can trigger hypothyroidism in dogs.
How do I know if my dog has hypothyroidism?
Diagnosing hypothyroidism can be complex and includes a good physical exam, presence of clinical signs or symptoms, and special blood tests that measure the amount of T3 and T4 (and other related hormones) in the bloodstream.
Antibodies against the thyroid can be measured if an autoimmune cause is suspected. Your vet can perform these tests and determine if your dog is hypothyroid.
Treatment of hypothyroidism in dogs
Treatment of hypothyroidism is relatively easy and most patients only need to take a small tablet of replacement thyroid hormone twice daily. Lifelong supplementation is usually required and blood tests to monitor thyroid levels are recommended at specific intervals throughout treatment. In many cases, clinical signs and symptoms begin to resolve within the first month of treatment but chronic cases may take longer to show improvement.
There are also natural supplements, like NHV Thyro-Up that can be added to improve the effectiveness of medication, and even help lower the dose of medication. The herbs in NHV Thyro-up help dog’s with hypothyroidism by helping to balance the thyroid, stimulating the immune system, and providing essential vitamins and nutrients.
Since with thyroid disease, there is a deficiency in nutritional intake, using a multivitamin like NHV Multi Essentials, and adding a high-grade fish oil supplement, like NHV PetOmega 3 will also be helpful.
The purpose of these supplements are to support the thyroid gland by increasing metabolism and lessening any symptoms of hypothyroidism.
If your dog has hypothyroidism, and you would like a second opinion, please contact me through NHV for an on-line vet consult.
Dr. Hillary Cook is a graduate of Virginia Maryland Regional Veterinary Medical school. She has been practicing holistic and integrative veterinary medicine for fifteen years. She certified in Veterinary acupuncture and is fully qualified in Western and Chinese herbalism. She is the owner of Animal Wellness Center, an integrative veterinary clinic in Crozet, VA. She enjoys spending time with her husband, two children, and a menagerie of pets including dogs, cats and chickens. When time allows, you can find her in the garden or on the tennis court!
Published: October 14, 2016