Is a Thyroid Problem Causing Your Pet’s Wasting or Obesity?

Is a Thyroid Problem Causing Your Pet’s Wasting or Obesity?

By Dr. Karen Becker DVM

Both dogs and cats experience disorders of the thyroid, but they’re usually affected in different ways. Dogs much more commonly develop hypothyroidism, or low thyroid hormone (thyroxine) levels, in the age range of 2 to 7 years.1 Cats, on the other hand, almost always develop hyperthyroidism, or high thyroxine levels, and it tends to occur in middle-aged and older kitties.

Thyroxine is an extremely important hormone in the body, playing an essential role in food metabolism, growth and development, oxygen consumption, reproduction and resistance to infection.

Causes of Canine Hypothyroidism

Your dog’s thyroid gland is a small butterfly-shaped organ in his neck at the base of his throat, with one lobe on each side of his trachea. There are a variety of things that can cause this little gland to fail. One is an immune system disorder called autoimmune thyroiditis, which means the body is attacking the tissues of the thyroid gland.

In response, the thyroid will first try to compensate by producing more and more hormone (thyroxine). But after a while, the gland becomes depleted. It’s at this point your dog develops symptoms of the disorder and is diagnosed with hypothyroidism.

Another way your dog can become hypothyroid is if the gland begins to shrink with age or becomes inflamed, producing less and less hormone over time, until eventually it doesn’t produce enough to support normal biological processes. A nutritional deficiency of iodine, tyrosine or the body’s inability to convert the amino acid phenylalanine to tyrosine can also result in hypothyroidism.

Other potential causes of hypothyroidism include certain medications, especially corticosteroids and exposure to endocrine disrupting toxins, including antigens in vaccines, which can ultimately lead to immune-mediated disease in the gland.

Symptoms to Watch For

Because an underactive thyroid affects so many bodily functions that rely on thyroxine, symptoms of the disorder vary widely and can be different from one dog to the next. Lack of energy, evidenced by frequent napping, exercise intolerance, or loss of interest in running and playing, is a hallmark sign of hypothyroidism. Other symptoms include:

Weight gain without increase in appetite or calorie intake Discoloration or thickening of the skin
Low tolerance for the cold Chronic infections of the skin or ears
Dull, dry, brittle, thin or greasy coat, dark coats can become reddish-brown Depression or mental dullness
Hair loss or failure to regrow clipped hair Slow heart rate
Dry, itchy skin and flakey nails Significant behavioral changes (e.g., aggression, head tilting, anxiety, compulsiveness, seizures)

If you suspect your dog has developed hypothyroidism, in addition to making an appointment with your integrative veterinarian, I encourage you to review this article for much more information on how the condition is diagnosed, including appropriate tests, and treating both simple and autoimmune forms of the disease.

It’s important to remember this condition doesn’t happen overnight and long before the diagnosis of clinical hypothyroidism there’s always declining thyroid levels, or “sluggish” hormone production (another great reason to include thyroid testing on your pet’s annual bloodwork).

If your dog’s thyroid levels are dropping over time but are still within range, “borderline” or “low normal” levels can be bolstered with a variety of thyroid stimulating nutrients, herbs and glandulars. I recommend partnering with your proactive vet to institute a protocol as soon as thyroid levels aren’t optimal to prevent fulminant disease.


Causes of Feline Hyperthyroidism

Feline hyperthyroidism is the most commonly diagnosed endocrine disorder in domestic cats, especially senior kitties. In fact, 95% of cats with hyperthyroid disease are 10 years or older.2 The disorder is typically caused by a benign tumor (adenoma) on the thyroid gland that causes overproduction of thyroxine, a situation that can cause serious, even life-threatening symptoms in cats.

Exposure to flame retardant chemicals (polybrominated diphenyl ethers, or PBDEs) has been linked to the development of hyperthyroidism in cats. PBDEs are recognized endocrine and thyroid disruptors.

In a 2015 study, researchers analyzed the blood from 60 pet cats for the presence of flame-retardant chemicals. The objective of the study was to evaluate the differences in the levels of chemicals in healthy cats vs. cats diagnosed with hyperthyroidism. Of the 60 cats in the study, 23 had normal thyroid function and 37 were hyperthyroid.

The study results showed that the hyperthyroid cats had higher blood levels of PBDEs on a fat weight basis; in essence, endocrine-disrupting environmental chemicals are making their way into our feline’s bodies at alarming rates.

Another earlier study suggested that flame retardant chemicals in house dust are linked to thyroid disease in cats. The study authors concluded that cats are primarily exposed to flame retardant chemicals by ingesting house dust — which occurs when they groom themselves.3

Housecats seem to have extraordinary exposure to PBDEs. In 2012, Swedish researchers demonstrated that serum PBDE levels in Swedish cats were about 50 times higher than in the Swedish human population,4 and a 2007 study showed that PBDE levels in U.S. cats were 20 to 100-fold greater than median levels in U.S. adults.5

A more recent study sheds even more light on the connection between flame retardant compounds and feline hyperthyroidism, suggesting that fish-flavored cat food could be a culprit.6 Scientists evaluated cat food and feline blood samples and discovered that the type of polychlorinated biphenyl (PCB) and PBDE byproducts found in both the food and blood samples are derived from marine organisms.

The researchers were also able to simulate the way in which the bodies of cats convert the type of chemical present in the food into the type of chemical seen in the cats’ blood samples.

Based on their results, the team concluded that the byproducts detected at high levels in cats’ blood samples likely came from fish flavored cat food and not exposure to PCBs or PBDEs. However, further work is needed to determine the link between the metabolites (byproducts) and hyperthyroidism.

Symptoms to Watch For, Especially in Cats Over 10

About half of all kittiesthat develop hyperthyroidism have an increased appetite, but ultimately, about 90% of them lose weight because a side effect of excessive thyroid hormone levels is an increase in metabolism.

Other symptoms of hyperthyroidism include high blood pressure; frequent vomiting; increased body temperature, heart and respiration rates (due to the up regulation of metabolic processes); hyperactivity, restlessness, nighttime yowling and eye problems in undiagnosed/untreated cases.

A combination of increased appetite, weight loss and sudden, unexpected bursts of energy in an older cat is a definite sign he or she may have an overactive thyroid. It’s important to make an appointment with your veterinarian as soon as possible.

If you suspect your kitty is hyperthyroid, in addition to making an appointment with your integrative veterinarian, I recommend reviewing this article for very important information on appropriate diagnostic tests, as well as information on how to both treat and prevent the disease.



Get Fit with a Pet ( you’ll both benefit)

By Dr. Becker and Diane Weinmannrunning with dog

A whopping 58 percent of cats and 54 percent of dogs in the U.S. are overweight or obese, according to the Association for Pet Obesity and Prevention.


This cuts down on your pet’s life expectancy by up to 2.5 years while raising her risk of serious diseases, including heart and respiratory conditions, diabetes, osteoarthritis, cancer and more. Further, there’s a “fat pet gap” in which nearly all owners of overweight pets believe their weight to be just fine.


Helping your pet maintain a healthy weight is one of the ultimate gifts you can give her. It might even save her life. So how do you know if your pet is overweight?


Your veterinarian can tell you for sure whether your dog is a healthy weight, but some telltale signs that your dog may benefit from weight loss include the following:

  • He has an oval shape when you look down on him from above
  • You cannot feel your dog’s ribs
  • You cannot feel the bones near the base of your pet’s tail (his pelvis)
  • You can see excess fat on his abdomen, hips and/or neck


A high-quality fresh food diet is essential for most pets in need of weight loss, but exercise is important too. You can even join in and get fit right along with your pet.

How to Get Fit With Your Pet

Pets’ health tends to mimic that of their owners, with older overweight owners tending to have overweight pets, and younger dog owners being more likely to have an overweight dog if they themselves were obese. The converse is also likely true, in that if your pet gets in shape there’s a good chance you will too, especially if you enlist your pet as your new workout buddy. Here are some examples of how to get fit with your pet.walker dog


  1. Stress Relief

A brisk daily walk is essential for your dog, and research shows it benefits owners too. Research published in the Journal of Physical Activity & Health found dog walking was associated with a significant increase in walking activity and leisure-time physical activity (LTPA). Before I was pitched from my horse and broke 5 bones I walked my dog daily and enjoyed our time together. It helped me get ready for vacation touring. Now I can barely walk at all without my crutches, vacations have been cancelled and I rely on my husband to walk our dog. They are both enjoy walking and are in good shape!

Compared to non-dog owners, dog walkers were 34 percent more likely to get at least 30 minutes of walking, five days a week. They were also 69 percent more likely to be active during their leisure time.

As you and your dog get fitter, you can increase the intensity and duration of your walks. If your dog enjoys it, you can even progress to running — just be sure to offer plenty of water and rest if your dog seems tired. Don’t forget to watch the weather. Rain, heat, humidity along with snow and ice can be dangerous for walkers.

  1. Tug of War

Many dogs enjoy a good game of tug-of-war and you’ll quickly learn that your dog is probably very strong — strong enough to give you a good workout, especially if he’s a large breed. Diane’s husky, Neko enjoys tug very much and tries to pull her off the couch. It’s a battle but she mostly lets him win because she is afraid for his teeth!

If your dog has back problems or issues with aggression and/or biting, tug of war is not the best choice.

  1. Play Fetch

A game of fetch can be immensely satisfying to your dog while requiring you to stay active (throwing and maybe even fetching the ball yourself if your dog leaves it behind).

Choose a secure area where you dog can run freely, like a fenced backyard, then ask your dog to sit before you throw the ball.

Wind up for a good throw and let your dog bring the ball back to you. To increase your own workout, use this opportunity to run with the ball and let your dog chase after you — then repeat.

  1. Agility Training

Agility training involves teaching your dog to run through obstacle courses, weaving around poles, going through tunnels, jumping through rings, walking on seesaws and more.


The physical and mental benefits to your pet are immense, and you’ll also work up a sweat while you run around the agility course with your dog.

  1. Bicycling

Your dog may enjoy trotting alongside as your ride your bicycle. Be sure you have a bicycle dog leash designed for this purpose, which keeps your dog secured and a safe distance away from the wheels.

You’ll need to start slow and bicycle at a lower speed — do not expect your dog to keep up with you pedaling at full force or for long distances. In addition, some dogs are afraid of bicycles and will not enjoy this form of exercise.

  1. Swimming

Some dogs are built for swimming, others can learn, and some detest the water. If your dog enjoys the water, swimming can be an excellent activity you can do together. Medium- to large-sized breeds with water-resistant coats and webbing between their toes are typically strong swimmers.

Dogs that aren’t designed for swimming include “top heavy” breeds — those with large chests and small hindquarters. Short-muzzled dogs, including the brachycephalic breeds, and dogs with very short legs also don’t do well in swiming


If you have a breed that isn’t physically built for swimming, but you think may be interested in learning to swim, my recommendation is to get help training him to swim in a controlled environment.

The water is dangerous for dogs that can’t stay afloat or tire out before they can swim to safety, so make sure you know how your dog will respond to water before assuming he can swim well.

Dr. Becker was able to train Rosco, her Boston Terrier (in theory not a “water dog”), to adore water and this proved to be the best exercise throughout his life. The same is true now for Lenny, her Dachshund.

If you do bring your non-swimmer to the lake or the beach, or even out to your backyard pool, I recommend putting a dog flotation vest and a very long tether rope on him to be safe.

  1. Backpacking or Hiking

A hike through a forest preserve or mountain trail can be exciting and invigorating for both you and your dog. Most trails require dogs to be kept on leash, and be sure to bring a plentiful supply of water and poop bags to clean up after your pet. Also, you’ll have an even better time if you choose a dog-friendly hiking trail.  The Cleveland MetroParks are a wonderful place to hike with your dog.  Diane, her husband and Neko, their husky, spend a lot of time on its trails.


  1. Tracking and Scent Games

Dogs excel at tracking scents, so why not make a game of it? Hide some bits of food in a few boxes and let your dog figure out which one contains the treat.

Then, take the game outdoors and let him search for food, clothing, items or you, using his nose as his guide. If you really want to see your dog’s tracking potential, and learn how to engage in tracking games with your dog, consult a local trainer or tracking club..


  1. Skijoring

Skijoring is a sport where your dog tows you along on cross-country skis. You’ll need a special skijoring harness for your dog that will hook up to a belt you wear via a towline.

You and your dog will have to learn to work together as a team, but once you get the hang of it, this can be a very rewarding and physically demanding activity for you both. Be sure to slowly acclimate your dog to this type of intense cold-weather activity.

Looking for a Workout Buddy? Try One of These Athletic Breeds

If you’re an active person looking for a dog to be active with you, some breeds will obviously be better than others. Those that follow are among the most athletic dog breeds that thrive on lots of physical activity. Even so, always watch for signs of overexertion in your dog (such as limping, heaving sides, excessive panting, stopping in his tracks, or extreme fatigue).

Many mixed-breed dogs in shelters also make excellent canine workout partners, but if you have your heart set on a specific breed, check out your local rescues. Your athletic buddy may be there waiting for you!

✓ Jack Russell Terrier ✓ Dalmatian ✓ Brittany Spaniel
✓ Greyhound ✓ Whippet ✓ German Shorthaired Pointer
✓ Australian Cattle Dog ✓ Standard Poodle ✓ Airedale Terrier
✓ Border Collie ✓ Weimaraner ✓ Siberian Husky


Now get out there, get yourself a furry work-out partner and get fit!work out catswim with dog

Fat Cat is NOT where it’s At!

By Dr. Becker and Diane Weinmanncat-in-overalls-photo-u2

Sadly, the majority of pet cats in the U.S. are either overweight or obese. According to the most recent research by the Association for Pet Obesity Prevention (APOP), 58 percent of American kitties are overweight, and 28 percent are considered obese.1

Even more discouraging is that an astonishing 90 percent of cat guardians think their too-heavy cat is a normal weight. According to Dr. Ernie Ward, founder of APOP:

“Pet owners think their obese dog or cat is a normal weight, making confronting obesity difficult. No one wants to think their pet is overweight, and overcoming denial is our first battle.”

Our animal companions have much shorter lifespans than we do. Depending on her breed and other factors, your kitty’s life is compressed into a short 12 to 20 years. And just as her lifespan is accelerated compared to yours, so too is the damage done to her body when she is forced to carry too much weight.

Yes, I said forced. There are no fat felines in the wild. It is humans who have created this problem, and it is humans alone who have the power to reverse the disastrous trend of an ever-increasing number of fat, sick, immobile, and short-lived pet cats.

I am serious when I say I have seen many fat felines. In fact, my mother-in-law’s cat is so fat he almost seems to drag his tummy. She feeds him treats constantly and he doesn’t really play or get exercise. Although, you must remember this is a cat belonging to a very sedate 83 year old woman. I would believe that pets belonging to our senior generation do not get a lot of exercise. This is a mistake but I doubt if you or I would be able to correct it.

So we must start now with cat owners that know better and can provide the stimulation and exercise a feline or dog needs to remain a healthy weight.

Fat Cats Routinely Become Very Sick Cats

There are so many reasons to prevent your cat from becoming overweight or obese. One of the most important is to insure your kitty has a good quality of life throughout her life. Another is so that you’ll have your pet with you for as long as possible.

  • Overweight pets often don’t live as long as pets at a normal weight. The shortened lifespan of a heavy cat can be the result of one or more obesity-related diseases.
  • Carrying around extra weight on a small feline frame places tremendous stress on joints, tendons and ligaments. This can cause arthritis. Tragically, in worst-case scenarios, senior cats immobilized by weight and intractable pain wind up euthanized.
  • Overweight cats have fat lurking in places you can’t see. For example, accumulations of fat deposits in the chest and abdomen can restrict the ability of your kitty’s lungs to expand, making breathing difficult.
  • Obesity is the biggest risk factor for diabetes mellitus in cats. Kitties fed processed cat food, in particular dry food (kibble), are at highest risk for developing this often difficult-to-manage disease.
  • Overweight kitties can also develop hypertension (high blood pressure), which can negatively impact major organ systems.
  • Hypertension does significant damage to a cat’s body. It causes small blood vessels to leak and in some cases, rupture. The result can be a detached retina or a stroke. High blood pressure also takes a toll on the kidneys and heart.
  • Overweight and obese cats are often predisposed to fatty liver disease, a potentially life-threatening disorder also called hepatic lipidosis. A buildup of fat cells in the liver prevents normal functioning. Left untreated, the liver ultimately fails and sadly, cats can and do die from this condition.
  • Your overweight kitty is also at greater risk for feline lower urinary tract disease (FLUTD). FLUTD is a group of disorders, any of which can affect your cat’s bladder or urethra, including cystitis (inflammation of the bladder), urinary tract infections, urinary stones, urethral plugs, cancer and other disorders.

Now, I am not one to talk—I am overweight, and yes, I have arthritis in my knees. Is that from being overweight? It is probably part of it—the other part is that I’ve had a horse since I was 18 years old and I ride constantly. Do I get enough exercise- in my estimation, yes! But maybe the ice cream and chocolate calories that I consume is too high for the exercise I get. Ya think?????

Given the tremendous risks associated with allowing cats to become overweight, I hope veterinarians and cat owners alike will heed the words of Dr. Steve Budsberg, Director of Clinical Research at the University of Georgia College of Veterinary Medicine:As an orthopedic surgeon I see, on a daily basis, the effects of obesity on dogs and cats with osteoarthritis. It is very frustrating to see how much pain and discomfort excess weight has on my patients.

 Nutrition and Exercise Recommendations for Overweight Cats

  • My mother-in-law the enabler! My dog and horse are not overweight and my cat (when he was alive) was not heavy either. I make sure they receive plenty of exercise based on the food they consume.
  • Veterinarians and owners have the ability to stop obesity in our pets. No animal goes to the refrigerator or the pantry and helps themselves. We enable our pets to get fat!”
  • “The prevention of obesity needs to be at the forefront of all discussions people have about the health of their pet with their veterinarian. The body of evidence that shows the negative impact of obesity on all the body’s systems is overwhelming.

Are You Enabling YOUR Cat to Be Fat?

  • Overweight cats are also at higher risk for surgical complications, decreased immune function, skin disorders, constipation, and certain types of cancer.
  1. In order to slim down an overweight cat, you must feed a portion-controlled, balanced, and species-appropriate diet. In my experience, most overweight cats are fed a dry diet and are often free-fed, which means they’re grazing day and night on food that is keeping them fat.

If your cat is still eating kibble, she’ll need to be slowly and safely transitioned to the right nutrition for her species: a low carb, moisture-dense, and fresh food diet. Not only will a better diet help with weight loss, it will make your feline companion much healthier overall.

  1. Next, make sure your kitty has at least one thing to climb on in your home, like a multi-level cat tree or tower. If he’s willing to use it, he’ll get some good stretching, scratching and climbing time in each day even when you’re not around.
  2. It’s important to keep in mind that your cat has a very limited attention span. Consider investing in a laser toy, either a very inexpensive, simple one or something more sophisticated like the FrolicCat. Many kitties will enthusiastically chase the beams or dots from these toys.
  3. You’ll also want to invest in a few interactive cat toys. To pick the best ones, consider things from your pet’s point of view. She’s a hunter, so when choosing toys and activities to engage her, think in terms of appealing to her natural instincts to stalk prey.

For example, if you have a cat toy like Da Bird, make it land and take off like the real thing. To keep her interest, every so often have the bird land on a tasty treat and let your cat discover it when she pounces on her prey.

5. Also keep some low-tech interactive toys on hand, like a piece of string you drag across the floor, ping-pong balls, or bits of paper rolled into balls. Any lightweight object that can be made to move fast and in unexpected directions will entice almost any cat to chase after it.

Your cat will tell you when he’s had enough, and you shouldn’t expect one game with one toy to go on for very long. Cats in the wild stalk prey for only a few minutes at a time and then move on.

  1. Turn mealtime into a workout session. Put your kitty’s food in a bowl, and then walk around the house with it, with her following close behind. Stop from time to time and offer her small bites of food. As she gets used to this new game, you’ll probably notice her being very active as she weaves around your ankles, runs ahead then turns back and runs towards you, stretches up toward the bowl, and hops around on her back legs.

After 10 to 20 minutes and a good little workout for kitty, you can put the bowl on the floor and let her finish up her meal.

A Word of Caution About Cats and Dieting

It’s extremely important that you diet your kitty slowly. I recommend you weigh your cat every week until he reaches his ideal body weight. Once that’s accomplished, you can weigh him every four to six months to insure he stays at his new healthy weight.

If your cat is obese, he should lose no more than a half-pound per month to prevent triggering a potentially deadly case of hepatic lipidosis. As your cat’s body senses weight being lost, it will begin to mobilize accumulated stores of fat. If weight loss occurs too quickly, the rush of fats being mobilized can overwhelm the liver and shut it down. Very overweight kitties are more prone to this life-threatening condition because their percentage of body fat is so high.

If your cat is only mildly overweight, he can probably safely lose up to a pound a month. What’s important is that his weight goes down and not up, but progress should be slow and steady. There’s no such thing as too slowly when it comes to weight loss in cats.

These weight loss timing guidelines are only suggestions. Some kitties should lose weight much slower than I’ve outlined here due to existing medical issues like diabetes and other chronic conditions. You should work with your veterinarian to determine a safe and healthy amount of weight loss for your cat, and the rate at which weight loss should occur.

It’s also very important that you not change your cat’s food while he’s dieting. If your cat rejects his food and won’t eat (which cats sometimes do when new food is introduced), it can cause a whole host of metabolic problems. This is especially true with overweight kitties.

Please talk with your vet about a meal and exercise plan for an overweight pet! You will be able to thank yourself later because you will have extended your pet’s lifespan…what a great accomplishment for both of you—not to mention all the more memories and love you can share together!