Printer Friendly Version
Thyroid Disorders in Cats and Dogs
The thyroid gland produces hormones that affect the body’s metabolism, growth
and development. The two most important hormones are tetraiodothyronine (thyroxine
or T4) and triodothyronine (T3). There are two conditions caused by a
dysfunctional thyroid gland – hyperthyroidism and hypothyroidism.
Hyperthyroidism is more common in cats and is caused by an overactive thyroid
gland with the resulting overproduction of hormones. Hypothyroidism, which is
more common in dogs, is caused by an under active thyroid gland that is not
producing enough hormones resulting in decreased metabolism.
Hyperthyroidism
Hyperthyroidism is diagnosed so often in cats that it has practically become an
epidemic. It is rarely seen in dogs. It is more common in older cats, but may be
seen in younger cats as well. Hyperthyroidism is generally a result of benign
(non-cancerous) changes or enlargement of the thyroid gland. It seems to be more
common among cats that have been fed sub-standard nutrition and food containing
artificial preservatives. Some holistic veterinarians feel they have seen an
increase in hyperthyroidism that corresponds to the increased vaccination rate
for feline leukemia. Viral and bacterial infections can also play a role, as
well as environmental toxins.
Prevention of hypothyroidism is the best approach through proper diet and daily
supplements, avoiding unnecessary vaccines, and minimizing exposure to chemical
or environmental hazards including cleaning products, X rays, antibiotics and
food preservatives.
Symptoms of hyperthyroidism include:
• Excessive thirst (in 10% of hyperthyroid cats)
• Excessive urination
• Increased appetite
• Weight loss (despite increased appetite)
• Hyperactivity
• Irritability or Aggression
• Vomiting
• Diarrhea
• Voluminous fatty feces
• Panting, Heat intolerance
• Skin lesions, dry, greasy, matted coat
Secondary problems include high blood pressure and heart disease. The increased
metabolic activity stimulated by the excess thyroid hormones cause an increased
heart rate which leads to an enlargement of the heart and thickening of the
heart walls. The increased pumping pressure of the heart leads to high blood
pressure.
Hyperthyroidism is best addressed with a team approach that includes
you, your veterinarian and a holistic veterinarian – either in your area or via
phone consultation. Some cats are excellent candidates for allopathic
treatments; some cats need a strictly holistic approach; many will do best with
a combination of both approaches.
The holistic methods of treating hyperthyroidism include improving the overall
health of the animal through improving diet and providing proper supplements, as
well as more targeted treatments such as constitutional homeopathy or Chinese
herbal remedies.
Diet
Feeding the best diet possible is the place to start. Feed the freshest food you
can –
raw is best,
freeze dried and
dehydrated follow that, then
canned, and
lastly dry food. Dry kibble should be a minimal part of the diet for cats. Cats
do not produce as much of the enzyme amylase, that digests carbohydrates, as
people and dogs do, so grains and other carbohydrates are more difficult for
cats to break down and digest properly. Cats need meat as the main portion of
their diet. (See the articles
What You Need to Know About Your Pet’s Food and
All About Raw Food for additional information on appropriate diets).
Hypothyroidism commonly occurs in cats that have some form of Inflammatory Bowel
Disease (IBD). Chronic vomiting and other symptoms of gastro-intestinal
disorders are often resolved through diet changes as outlined above. In addition
to feeding the freshest food possible, the diet should be free of common
allergens such as wheat, corn, soy and dairy. See
Inflammatory Bowel Disease &
Other Gastrointestinal Issues for more information about treating IBD.
Supplements
Carnitine is an amino acid that has been shown to prevent or reverse
hyperthyroid symptoms in humans, and is often recommended for cats as well.
Since hyperthyroidism tends to deplete the body of carnitine, supplementation is
recommended anyway. Cats can be given 125 to 250 mg 2 times per day.
Chinese herbal formulas are frequently a part of a comprehensive approach to
hyperthyroidism.
Thyroid Calming by Nature’s Herbs for Pets is designed to aid in
balancing thyroid function. More advanced Chinese herbal remedies may be
prescribed by your holistic veterinarian.
The herbs Bugleweed and Melissa (lemon balm) are western herbs used
traditionally in the treatment of hyperthyroidism in cats. These should be used
under the supervision of a holistically trained veterinarian.
Constitutional Homeopathy has also been successful in reversing hypothyroidism,
particularly in the early stages. Constitutional homeopathy takes into
consideration the whole patient, the totality of all symptoms including
physical, mental and emotional states. A classically trained homeopath will ask
many detailed questions in order to obtain a complete picture of the individual
and match this to the most appropriate remedy. To find a holistic veterinarian
that practices homeopathy near you, check the
American Holistic Veterinary
Medical Association or Academy of Veterinary Homeopathy referral directories.
Flower essences can support your pet’s emotional well-being during his
treatment.
Thyroid Balance Flower Essence by Pet Essences may help calm the
irritability or ease depression that often occurs with hyperthyroidism.
Hyperthyroidism often masks underlying kidney disease in older cats. It is not
uncommon to bring the thyroid under control only to find that the patient needs
treatment for kidney disease within months. For this reason it is even more
important to improve the diet as much as possible and provide daily supplements
for optimal overall health including a good
daily multivitamin,
digestive
enzymes,
essential fatty acids, and
vitamin C.
Hypothyroidism
Hypothyroidism is more commonly seen in dogs than cats. It is typically a result
of physical degeneration of the thyroid gland – either from an autoimmune
response or atrophy of the thyroid gland. Some holistic veterinarians believe
this degeneration may be related to environmental toxin exposure, poor diet and
nutrition, over-vaccination, or a combination of these factors. Some dogs have a
genetic pre-disposition to the disease. Breeds that are more commonly affected
include Golden Retrievers, Doberman Pinschers, Greyhounds, Irish setters,
Dachshunds, and Cocker Spaniels. Hypothyroidism is rare in toy and miniature
breeds of dogs.
Over 80% of hypothyroid dogs show some kind of skin abnormality such as
thickening in some areas, darkening pigmentation, dry skin, or infections. Other
symptoms of Hypothyroidism may include the following:
• Lethargic behavior (lack of interest in play, frequent napping, tiring out easily)
• Weight gain, sometimes without an apparent gain in appetite
• Hair loss, especially on the trunk or tail (without associated itching)
• Cold intolerance/seeking out warm places to lie down
• Slow heart rate
• Chronic ear infections
• Behavioral changes such as aggression, anxiety and/or compulsivity
• Depression
These symptoms will appear gradually, so it is not uncommon for guardians to
miss the initial stage of the disorder. It is generally seen in middle-aged or
older dogs.
Hypothyroidism is difficult to diagnose despite its seeming simplicity. It is
not so straight forward as testing for low thyroid hormone levels and
prescribing synthetic hormone replacement. There are a variety of tests
available to determine the level of thyroid function and hormones available in
the system. Endocrinologists may use multiple tests to make a proper diagnosis.
Some veterinarians will prescribe a trial period of synthetic thyroid hormone
and, if the response is positive, use this as the means of diagnosis. The
problem with this method is that synthetic thyroid hormone acts as a stimulant,
so most dogs will respond with increased activity and interest in life. If a dog
that is not truly hypothyroid is kept on synthetic thyroid hormones for an
extended period, the increased metabolic rate can tax the dog’s system -
hastening the aging process and leading to other degenerative conditions. In
addition, the use of synthetic thyroid hormone can hasten the degeneration of
the thyroid gland. As you can see, proper diagnosis is rather important.
Since most hypothyroid dogs will retain at least some function of the thyroid
gland, it may be very useful to support the function of the thyroid gland
through the use of supplements, herbs and glandulars – possibly in combination
with synthetic thyroid hormone depending on the stage and severity of the issue.
Again, diet is the place to begin (see above under hyperthyroid treatment). A
high quality diet supports the body in managing its own endocrine system. As
with treating any health issue, provide daily supplements for support of overall
health including a good
daily multivitamin,
digestive enzymes,
essential fatty
acids. Essential fatty acids can be helpful in treating some of the skin
abnormalities resulting from hypothyroidism.
Chinese herbal formulas are can be particularly helpful in treating
hypothyroidism.
Thyroid Boost by Nature’s Herbs for Pets is designed to aid in
balancing thyroid function. Again, more advanced Chinese herbal remedies can be
prescribed by a holistic veterinarian.
Thyroid Balance Flower Essence by Pet Essences may help address any emotional
and behavioral issues resulting from the thyroid imbalance.
Glandular supplements can be prescribed by a holistic veterinarian and are often
helpful in supporting thyroid function.
Additional articles of interest
What You Need to Know About Your Pet’s Food
All About Raw Food
The Importance of Daily Supplements for Your Companion
Inflammatory Bowel Disease & Other Gastrointestinal Issues
Dealing with Kidney Failure in Cats and Dogs
The Truth About Pet Vaccinations
Resources
"A Manual of Natural Veterinary Medicine" by Dr's Susan Wynn and Steve Marsden
“Herbs for Pets” by Mary L Wulff-Tilford & Gregory L Tilford
“The Nature of Animal Healing” by Martin Goldstein, DVM
VeterinaryPartner.com - The Pet Health Library – “Hypothyroidism in Dogs” by
Wendy C. Brooks, DVM, DipABVP
“Dr. Pitcairn’s Complete Guide to Natural Health for Dogs & Cats” by Dr. Richard
Pitcairn
|