What is Hypothyroidism?
Hypothyroidism is the term used to describe low thyroid function. Unfortunately, hypothyroidism is a very common yet also a commonly missed condition for both people and pets. While it’s much more likely for dogs to develop hypothyroidism than it is for cats, it isn’t completely unheard of for our fabulous felines to suffer from this issue as well.
Sadly, however, the ability to confidently and accurately identify hypothyroidism is less than optimal with current testing methods. In addition to that, comprehensive understanding of the complex pathways and interactions of thyroid hormones, particularly for women, as well as the current conventional healthcare approach to patient interviewing to determine the root cause of thyroid disease is, at least in the human medicine world, somewhat lacking.
Knowing that confidently identifying those who are already suffering from or are at higher risk of this condition isn’t quite where we would like it to be, where do we go from here? Let’s unpack.
#1- Understand the Pathophysiology
There are several important hormones that you need to be aware of to understand thyroid function. First is TSH, which stands for thyroid stimulating hormone. This is the most common thyroid value you’ll see discussed in the natural and holistic pet space because it is the most commonly checked of all thyroid related levels. The TSH is actually released by the pituitary gland, which is located in the brain and has a close relationship with the endocrine system, of which the thyroid is included. The TSH travels to the thyroid and, as the name implies, stimulates it to produce thyroid hormones.
T4 and T3 are the two thyroid hormones that are produced by the thyroid. T4 is called Thyroxine, and T3 is called Triiodothyronine. Of the two, T3 is the one that is the more active form for use in the body. However, T4 is the one that is produced in higher quantities by the thyroid gland. T4 actually has to then be converted into T3 to exert a significant effect on the tissues.
Within the T4 and T3 values, you have what is called free T4 & T3, and total T4 & T3. The free levels are the ones are actually available to move and work in the body because they are, as the name explains, free- they aren’t bound to anything. Total levels include both free and bound hormones and there is no way to know how much of each is in that level, which is very important. T4, usually free T4, is the second most common thyroid level you will see drawn and discussed.
Understanding the relationship between these hormones can be a little confusing, because they are inversely related. If the thyroid is hyperactive, or working too much, then the TSH will be low while the T4 would be high. On the other hand, if the thyroid is hypoactive, meaning it is working too little, the TSH will be high while the T4 will be low. Let’s break that down a little more.
Remember that TSH stands for thyroid stimulating hormone which is produced by the pituitary gland and works on the thyroid gland by telling it to make more hormone. So it makes sense that if your thyroid is already working too hard and making too much thyroid hormone, then the body doesn’t want to stimulate it to keep making more thyroid hormone. Therefore the thyroid stimulating hormone (TSH) drops below normal in an attempt to turn the thyroid off. On the other hand, if your thyroid isn’t really up to snuff, and isn’t making thyroid hormone, then it makes sense that your thyroid stimulating hormone levels would be high, because the body is trying to wake up the thyroid and get it to do its job. So, to recap:
- Hyperthyroidism= low TSH & high T4
- Hypothyroidism= high TSH & low T4
But just because we like to make things confusing, there is another low thyroid lab pattern you can see, and that is one of subclinical hypothyroidism, also called sick euthyroid syndrome. What this essentially means is that the thyroid is not working optimally, and one has symptoms of hypothyroidism, but the lab values may actually be normal. Or, the lab values show a high thyroid stimulating hormone, indicating that the body is working extra hard to get the thyroid to make the necessary hormones, but the level of those hormones is actually normal. This should still be treated as impaired thyroid function.
#2- Standardize the Testing
When it comes to testing for suspected thyroid disorders, the most commonly tested lab value is a TSH. Some labs will perform a ‘TSH with reflex free T4’ which means they will automatically run a free T4 level if the TSH is abnormal. The problem is that many people and pets have symptoms of hypoactive thyroid with what would be considered ‘normal’ labs. This is because we have a rather broad range of numbers that are reflective of only the average of a given population and doesn’t allow for variations of the individual. This is not best practice medicine when you’re trying to take an individualized approach.
In addition to the wide range of ‘normal’ values, many providers also aren’t checking all the labs together in the combination that will give them the most accurate picture of the potential problem. Despite knowing that T3 is a more potent hormone, we aren’t measuring these levels, nor do most practitioners check a total T4 to compare to a free T4, or antibody levels, or reverse T3 routinely either. Instead, many of them check only a TSH and nothing else if the TSH is normal. However here are some examples of when that single lab method may fail you:
- The body is starting to show signs of hypothyroidism, but it isn’t yet enough to elevate the TSH. Despite this, the T4 could already be low.
- The body is doing a poor job of converting T4 into T3 for optimal use. In this instance, we may see an elevated TSH indicating that the body is trying to get the thyroid to work harder, but a normal T4. If the issue lies with the conversion of T4 to T3, then you would never know if you stopped at testing a T4 only.
- The body could be creating immune mediated thyroid antibodies, which are binding the thyroid hormone and making it inactive. If you don’t check a total T4 and a free T4, you wouldn’t know that this is happening.
- When under stress, the body can produce reverse T3, which binds to the T3 receptors and blocks T3 from exerting an effect on the body. You need to test reverse T3 to know this.
So you can see that there are nuances that individuals can experience that really make checking all the levels, or at least several in combination, helpful in order to determine what type of hypothyroidism one is present.
#3- Avoid Taking “The Buck Stops Here” Approach
Once one has been told “you have hypothyroidism,” often the recommendation is a synthetic supplement for life and nothing else. This is the worst thing you can do in the instance of hypothyroidism for you or your pet. When you stop at a dlagnosis, which is simply an expression of symptoms associated with an imbalance occurring in the body, rather than try to get to the root cause of that imbalance and fixing it, you’re only putting a bandaid on the problem rather than resolving it. So what can we do instead of, or in addition to, supplementation?
A. Optimize Nutrition
It should be obvious by now that a food first approach is necessary for both maintaining health and resolving disease. In the case of hypothyroidism, it’s no different. There are several nutrients that are particularly important for optimal thyroid health and function.
First, we have Selenium. This is a mineral that is necessary for a healthy thyroid due to its involvement in the creation of T4 and conversion of T4 into T3. Animal sources of selenium include small fatty fish, shellfish, beef and chicken liver, and beef and lamb kidney. Plant sources of selenium are first and foremost Brazil nuts, as well as raw garlic and mushrooms. In fact, just two Brazil nuts contain about 200mcg of selenium, which is the optimal daily intake for an average adult. For dogs, the recommended amount depends on their size.
Next is Iodine, which is an important mineral for thyroid health due to its help with synthesizing T4. It’s found heavily in kelp, algae and seafood. Iodine is also present in land animals but unfortunately the USDA doesn’t require testing of iodine, so it is difficult to tell how much you may be taking in from land animal-based sources. That said, it’s not nearly as much as from sources you’d find in the water.
Zinc is the third mineral that is quite important in terms of thyroid health. Zinc helps with the creation of T4 and with the conversion of T4 into T3 for use in the tissues. Zinc along with Iron increase the sensitivity of the target tissues so that the T3 has an easier job of exerting an effect,.
Several vitamins assist in the creation of T4 as well, including Vitamin A, D, E, B2, B3 and B6. Vitamin A has the additional benefit of increasing the sensitivity of the peripheral tissues to T3 just like Zinc does. These vitamins are abundant in organ meats, especially liver, and especially grass fed ruminant liver.
Minimizing inflammatory foods is also helpful, since being in an inflammatory state can provoke the immune system and lead to the development of autoimmune disorders. This means overall choosing foods that support the gut and immune health, such as fermented foods, grass fed and pasture raised land animal proteins, wild caught and sustainably sourced fish, and organic fruits and vegetables. Likewise, you should avoid foods such as seed oils, oxidized fats, and processed carbs.
B. Increase Exercise
I know- exercising isn’t for everyone. I wish I could exclude it from my discussion, but the truth is that if we don’t move, we don’t stimulate our mitochondria to create the energy we need for everyday functioning. In addition to that, exercise helps improve the uptake of T3 in peripheral tissues. Therefore, if your dog is having issues converting T4 into T3, and we want them to be as efficient as possible at using the T3 they have, exercise is one factor you cannot exclude.
How much exercise is enough exercise? Even 15 minutes per day of steady walking can make a difference. At least one hour three times a week is an optimal minimum. And more than that, as tolerated, is excellent.
C. Reduce Toxin Exposure
Unfortunately, we live in a toxic world. Things like artificial fragrances, dyes, and chemicals can be potent endocrine disruptors and significantly affect thyroid health. Removing these things from our homes can only be beneficial in the long run. Try replacing dryer sheets with wool dryer balls and dropping a few drops of pure, organic essential oils on them for a gentle and natural scent after drying that is free of chemicals. There are countless recipes for DIY soap, cleaning spray, laundry detergent and more. Essential oil diffusers can replace scented candles and plug-ins. The Forever Dog Life book is full of recipes and for the low price of under $25, you can’t go wrong grabbing that book.
Perhaps even more dangerous yet more difficult to detect are heavy metal toxicities. Sadly, we are exposed to metals from sources one might not expect, such as our water supply, fillings in the teeth (although that example is selectively a human problem), poor quality supplements and more. The issue lies in not only identifying where you might be encountering these metals, but that you even have a toxic load in the first place. Symptoms of hypothyroidism can mimic heavy metal toxicity, such as fatigue, weight fluctuations, hair loss or depigmentation, etc. So if you or your dog are showing signs of hypothyroidism and focusing on the above methods doesn’t improve symptoms and lab values, consider checking for heavy metal buildup using HTMA testing. If you use this link for ParsleyPet and use the code RAWPAW at checkout, you’ll receive $25 off a test. I personally used ParsleyPet for myself and my dogs- yes they test humans too!- and have had several clients test through them as well, all with excellent results.
Get it? Got it? Good!
There you have it, some guides for understanding, testing, and approaching hypothyroidism naturally. Unfortunately, hyperthyroidism is its own beast, and something that needs to be discussed separately, so keep an eye out for that in the near future. Until then, go support you and your dog’s thyroid health through food, exercise and clean living!
