Important Facts that You Need to Know About Hypothyroidism in Canines, Felines and Humans

Posted on May 14th, 2017

What is the internet definition of hypothyroidism?

Hypothyroidism = abnormally low activity of the thyroid gland resulting in the retardation and development of children and adults.

However, medical science has discovered many more clinical signs and clinical symptoms for patients that are suffering from hypothyroidism which include canines, felines and humans.

What are the causes of hypothyroidism?

The Mayo Clinic lists the following causes of hypothyroidism:

. Autoimmunity: an autoimmune disease which is caused by the

  production of anti-thyroid antibodies.

. Treatment for hyperthyroidism with the over use of radioactive iodine

  and anti- thyroid drugs.

. Surgical removal of the thyroid gland.

. Increased amounts used with radiation therapy.

. Too much medication that regulates thyroid function.

, Congenital disease that creates the development of a defective

  thyroid gland.

. Pituitary dysfunction in the production of TSH, which stands for

  Thyroid Stimulating Hormone.

. Pregnancy. Apparently many women during their pregnancy produce

  anti-thyroid antibodies.

. Iodine deficiency. Iodine must occur in the diet and is essential for the

  production of normal thyroid hormones.

Considering my own clinical studies, the following are some other reasons why a state of hypothyroidism may occur:

1) If the patient has a cortisol that is deficient, defective or bound

   T4 (thyroxin), which thought to be a storage thyroid

 hormone, will not be transferred into active thyroid hormone, which

  is T3 (triiodothyronine)

2) If a hypothyroid patient has an elevated Reverse T3 and is prescribed

  a T4 supplement, that T4 supplement may be converted to more T3,

3) If total amounts of estrogen, including adrenal estrogen is in excess,

  those elevated amounts of estrogen will bind the receptor sites for

  both T3 and for T4, causing a state of hypothyroidism.

NOTE: Because of the elevated amounts of estrogen, I have found that a patient can have normal amounts of thyroid hormones and still be demonstrating signs of hypothyroidism.

This again, is due to the fact that the elevated amount of estrogen will effectively block their T3 and T4 receptor sites.

I refer to this condition as metabolic hypothyroidism. For further information on metabolic hypothyroidism, please Google this topic with my name.

What are the clinical signs of hypothyroidism in canines and felines?

The following is a list of those clinical signs:

, Lethargy

. Signs of an overall weakness

. Lack of activity

. Loss of certain mental capacities

. Increased weight for no apparent reason

. Major hair loss and shedding

. Poor hair regrowth

. Slow wound healing

. Seizures

. Infertility

My studies also indicate that the following clinical signs may also occur with hypothyroidism in canines and felines.

Those clinical signs are:

. Lipomas

. Sebaceous cysts

. Papillomas (warts)

. Skin tags

. Skin rashes

. Constipation

. Often increases in serum triglycerides and cholesterol

I would expect many more clinical signs to be described, if only the canines and felines could speak!

What are the clinical signs and symptoms for humans?

The Mayo Clinic lists the following clinical symptoms for hypothyroidism:

. Fatigue

. Increased sensitivity to cold

. Constipation

. Dry skin

. Weight gain

. Puffy face

. Muscle weakness

. Hoarseness

. Increased serum cholesterol

. Muscle aches, tenderness and stiffness

. Pain, stiffness and swelling in the joints

. Thinning hair

. Slow heart rate

. Depression

. Impaired memory

Unfortunately, I have had an endocrine immune imbalance myself for over 35 years that I have been able to control, however I was still left with some clinical symptoms of hypothyroidism.

Fortunately I have been able to safely increase my replacement hormone supplements, in order to alleviate those clinical symptoms.

These were my clinical symptoms of hypothyroidism that may not be listed on the internet,

1) Excess tearing.  Hypothyroidism will cause a “dry eye” syndrome, which will cause excess mattering of the eyelids and a compensatory production of tears, causing watery eyes.

2) Bruising. This is very common event, which I originally blamed on my

  high blood pressure medication.

3) Swelling of the feet and ankles. Originally I blamed this on gout and

  increased amounts of uric acid, but this was not the case. The medical

  literature indicates that hypothyroidism is the most common cause of

  swelling in a human.

4) High blood pressure, Even with all the different blood pressure

  medications I have been taking over the years, my pressure was

  definitely better, but not perfect.

  However, once I increased my thyroid supplement, my blood pressure

  dropped into the normal range.

.5) Papillomas, lipomas and sebaceous cysts. Once my hypothyroid

  supplement also normalized my imbalance, papillomas, lipomas and

  sebaceous cyst either began to regress or entirely stopped growing.

6) Constipation. No more constipation or problems with my esophagus

  while trying to swallow food.

7) Insomnia. Once properly medicated, my insomnia stopped and I was

   able to get a good night sleep.

8) Blurred vision. My blurred vision improved to a point where I was able

  to sew without having to wear the eyeglasses that I had purchased earlier

  before increasing my thyroid medication.

9) Dry mouth. I had also suffered from a lack of saliva, which not only

  caused me to have a dry mouth but also caused me to snore

  Both these conditions disappeared once I increased my thyroid


These are just a few examples of what I have encountered with my hypothyroid imbalance that I wanted to share with you.

What are some of the do’s and don’ts you need to know about when taking your thyroid supplement?

  • Never take your thyroid supplement before having your thyroid test done. Medical literature states that a human should make sure there is at least 5 hours after taking their thyroid supplement, before taking their thyroid blood test.

NOTE: I find it best to do the test in the AM, before noon and then take your thyroid medication.

NOTE: This seems not to apply to canines and felines, because of their increased metabolism, which allows the liver to breakdown the thyroid medication and the kidneys to excrete the end products, within 12 hours.

In humans the thyroid medication will last 24 hours and that seems to be the difference.

  • The reason for this doing this is because if you take the thyroid supplement before doing the thyroid test, the test results will be above normal, possibly indicating that you may be being over medicated. I would also think, if you did take the thyroid supplement before being tested, and your thyroid levels were in the normal range, this would indicate that you might need more thyroid supplement, but this would be something to check with your health care professional.
  • It is best to take a supplement on an empty stomach, in order to reduce the possible malabsorption from foods.
  • The medical literature is now indicating that it might be more efficient to take the thyroid supplement at night.
  • Never take a thyroid medication or increase the amount of thyroid medication you are taking, without first checking with your health care professional. If you do take or increase the amount of thyroid hormone you are taking, without first checking with your health care professional, you can put yourself into a situation where your blood pressure will become high enough to cause you to have a fatal heart attack or fatal stroke!
  • Make sure you are also tested for Thyroid Binding Globulin (TBG) If your are hypothyroid, because if your TGG is elevated and you are prescribed only a T4 supplement like Synthroid or Thyroxin, they will only increase your TBG and you will still suffer from the effects of hypothyroidism. In this instance, a T3 supplement is indicated.
  • I have also found by dissolving my NP Thyroid medication under my tongue, its effectiveness is much greater than when merely swallowing the tablets.
  • To determine whether a patient is truly hypothyroid or merely is showing the clinical symptoms of hypothyroidism with normal levels of T3 and T4, I would suggest considering doing the following list of blood tests in conjunction with the other standard blood tests your healthcare professional may prescribe:


. Cortisol

. Total estrogen

. Estradiol

. Total T3

. Total T4



. Iodine

. Tyrosine

. IgA

. IgM

. IgG


These are just a few of my clinical observations and experiences with hypothyroidism that I thought you might find of interest.


Dr. AL Plechner