Hypothyroidism is a deficiency of thyroid hormone in the body. Thyroid hormone is produced in the thyroid gland, located in the neck. This hormone affects many functions in the body including:

  • Increasing the metabolic rate
  • Improving the quality and condition of the skin
  • Improving nerve conduction
  • Blood Clotting System

Hypothyroidism can occur from either a lack of production of the hormone by the thyroid gland, by a deficiency of either of two brain hormones (thyroid stimulating hormone, or thyrotrophic releasing hormone) that control the thyroid gland itself, or because of a problems with antibodies destroying the thyroid hormone once it is produced. Regardless of the cause, hypothyroidism will lead to any of the following symptoms in your pet and they may be exhibited to varying degrees:

  • Weight Gain
  • Sluggishness
  • Recurring skin infections
  • Sparse hair coat
  • Flaky skin
  • Pigmentation of the skin
  • Bleeding Disorders
  • Neurologic disorders

How does our veterinary team diagnose hypothyroidism?

Diagnosis of hypothyroidism is done through blood testing. Sometimes our veterinarians detect this problem when running a general health screen that includes thyroid function tests. If we suspect hypothyroidism, we generally submit a thyroid diagnostic panel that looks at every aspect of thyroid metabolism. Currently, these tests may take up to 1 week to come back to us.

How do our veterinarians treat hypothyroidism?

Treatment of hypothyroidism consists of replacing the pet’s missing or non-functional thyroid hormone with a synthetic replacement drug called Thyroxine. Our goal is to return the pet’s thyroid hormone (measured by the T4 value) to the normal level. To begin therapy, we start your pet on a dose of Thyroxine that is calculated based on the weight of your pet. Then, our veterinary team check the blood level of T4 about 10 to 14 days later to see if the calculated dose turns out to be the correct dose. Some pets absorb the drug differently than others and therefore, we can’t assume that the calculated dose is correct without this confirmatory test. Generally, Thyroxine is given twice daily for the remainder of your pet’s life.

What can our veterinary team expect to see from therapy?

Appropriate treatment of hypothyroidism will generally reverse the signs and symptoms that were detected prior to treatment. However, many hypothyroid related symptoms (especially skin related problems) will likely require additional therapeutic steps in order to correct them. Overweight pets will generally start to lose weight, but we must administer the appropriate type and amount of diet to accomplish this. Our doctors will provide specific therapeutic plans tailored to your pet’s needs.

What are the possible side effects of therapy?

Thyroid hormone can be toxic if given in excess of the body’s needs. Signs of overdosing include irritability, hyperactivity, excessive weight loss, rapid heart rate, rapid breathing and excessive hunger. If uncorrected, overdosing can lead to hypertension, strokes, and heart failure and even death.

What happens if I miss a dose?

Missing an occasional dose of Thyroxine is not a major problem, as the effects of thyroid hormone deficiency are not generally seen immediately. However, it is important to be as consistent as possible with your dosing and not to simply stop the drug completely. Some pets that have become accustomed to getting Thyroxine may go into a crisis if supplementation is stopped abruptly.

How does our veterinary team monitor our therapy?

Over time, the blood values of T4 can change even if the pet is taking the same dose of Thyroxine. Therefore we need to check the thyroid level every 6 months to ensure the continued efficacy of our therapy. If your pet loses more than 5-10 pounds (which is very likely during the initial stages of therapy) then we need to recheck the T4 level to be sure that we are not overdosing your pet (remember, the original dose was calculated at the original weight, a lighter pet requires less thyroid hormone). Thyroid supplementation can affect many organ systems in the body and so we routinely require a physical exam and general blood chemistry profile be performed at least once a year for our hypothyroid patients.

What are the costs of keeping a pet on Thyroxine therapy?

  • The cost of Thyroxine is very reasonable and should run about 10-20.00 per month for the drug itself
  • Blood chemistry profiles cost about $120.00 and are performed before treatment is started and once yearly thereafter.
  • T4 blood levels are run 10 days after beginning therapy. The test is generally run 4 hours after the morning pill. If the dosage is correct, the next test will be run 6 months later. If the dose is too high or too low, the dose is adjusted and the test must be run again in 10 days to ensure that we are at the right amount. These tests run about $45.00
  • All pets on thyroid supplementation must have a physical exam (currently $38.00) performed at our hospital once yearly.

Once your pet’s Thyroxine dose has been determined we generally dispense 1-2 months worth of the drug to you at a time. Refills are available for up to 6 months. At 6 months we require the T4 test to be run prior to refilling the drug. If the dose is correct, then another 6 months of refills will be dispensed.
To help us serve you smoothly, please try not to wait until you have run completely out of the drug before calling for a refill. We ask that you give us at least 24 but preferably 48 hours notice to refill the drug.

If you have any questions regarding this or any aspect of your pet’s health care, please feel free to speak with our veterinarians in person or over the telephone.

As we begin therapy for your pet’s hypothyroidism, we ask that you sign the agreement below to avoid any miscommunication about this therapy and our hospital policies surrounding it.

I, ___________________________ have read the information above and do declare that I understand the goals and limitations of hypothyroid therapy for my pet, the possible side effects of the drugs and the policies surrounding monitoring of my pet during treatment. I fully understand that Alta Rancho Pet & Bird Hospital or any of its agents has made no promises or guarantees regarding the outcome of this therapy. I understand the importance of monitoring the effects of therapy on my pet. Therefore, I agree to have Thyroxine blood levels run on my pet’s blood every 6 months, as well as an annual blood chemistry profile run while my pet is under the care of Alta Rancho Pet & Bird Hospital for this disorder. I further understand that drug refills will not be granted if these tests are not run. Finally, I understand that it is my responsibility to request refills of this drug at least 24 hours prior to needing the drugs.

Signed: ___________________ Date: ________ Staff: _____________