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Hormonal Imbalance in Dogs: 9 Vet-Explained Signs & How to Treat It

Written by: Dr. Megan Barnes BVSC MRCVS (Veterinarian)

Last Updated on April 29, 2024 by Dogster Team

Sad tired beagle dog on sofa. Sick dog.

Hormonal Imbalance in Dogs: 9 Vet-Explained Signs & How to Treat It


Dr. Megan Barnes  Photo


Dr. Megan Barnes

BVSC MRCVS (Veterinarian)

The information is current and up-to-date in accordance with the latest veterinarian research.

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Dogs may stand on four legs and spend an inordinate amount of time with their noses up each other’s bottoms, but their hormones function similarly to ours. Hormones are chemicals released by glandular tissue in the body, and they control the actions of certain organs and cells. They play a huge part in the physiology and functioning of the body, influencing everything from behavior to growth and metabolism. You may recognize a few hormones: estrogen, testosterone, thyroid hormone, insulin, and cortisol. These all act on different parts of the body to induce certain effects.

When hormones become imbalanced, it produces a range of diseases in the body. Hypothyroidism, hyperadrenocorticism (Cushing’s disease), hypoadrenocorticism (Addison’s disease), and diabetes are all manifestations of hormones acting up. There are three possible causes of hormone imbalance in the body: over-production of a hormone, under-production of a hormone, or the inability of the hormone to function correctly.

Read on to learn more about the signs of hormonal imbalance in dogs and what you can do about it.


The 9 Signs of Hormonal Imbalance in Dogs

1. Symmetrical Hair Loss

Hair loss, or “alopecia,” is common with many hormone disorders. The pattern of alopecia will differ from other causes of hair loss, such as skin disease and trauma, in that the hair loss is often generalized on both sides of the body and is symmetrical. With skin diseases, including parasites and allergies, hair loss is usually irregular and patchy.

Symmetrical hair loss, especially when coinciding with other clinical signs, will often prompt concern for a possible issue with the endocrine system. Usually, once the underlying condition is treated, the hair growth will resume.

alopecia disease in samoyed dog
Image Credit: Zanna Pesnina, Shutterstock

2. Increased Urination and Thirst

When a veterinarian asks you whether there have been any changes to your pet’s thirst and urination behaviors, it is usually so that multiple illnesses can either be confirmed or ruled out. The medical terms for increased thirst and urination are “polydipsia” and “polyuria” and can indicate a few possible diseases relating to hormone imbalances, such as Cushing’s disease and diabetes.

If there have been changes in your dog’s drinking and toileting habits, the next step is usually to test their urine and to take a blood sample to check for any underlying disease.

3. Increased or Decreased Appetite

A change in appetite can indicate several hormonal disorders. You may see a voracious appetite in those dogs afflicted by diabetes, as their body simply cannot transport glucose into their cells because they are deficient in insulin (the hormone essential for transporting glucose from the bloodstream and into the cell), and since the cells are energy deficient, the body (despite eating) is starving.

You may see a decreased appetite in those with hypothyroidism or Addison’s disease. Essentially, if you notice any changes in your dog’s appetite, even if they seem hungrier than normal, and it is associated with any other clinical sign, it is worth getting them checked out by your veterinarian.

dalmatian dog looking sick
Image Credit: Alexander Hagseth, Shutterstock

4. Weight Loss or Weight Gain

Hormones have a direct effect on metabolism. For example, producing too much or too little thyroid hormone can cause the metabolism to work too fast or slow down. When not enough thyroid hormone is secreted and the metabolism slows, this can result in weight gain despite having a decreased appetite.

Conversely, diseases like diabetes can result in significant weight loss despite an increased appetite. So, a weight change that is sudden, unexpected, and unrelated to purposeful diet changes or caloric alteration is definitely a cause for concern.

5. Scaly or Dry Skin

Evidence of a hormone imbalance can be seen on a dog’s skin. For example, one function of reproductive hormones is to stimulate oil glands in the skin. When there are low sex hormones in the body, the skin can become dry and flaky. The same can be said for hypothyroidism.

When the metabolism is downregulated, so too are the sweat glands, which can cause dry skin. So, if your dog has dry, flaky skin that isn’t itchy or the result of allergies or irritation, you may need to ask your vet about hormone disorders.

dog with scaly skin
Image By: Oka diana, Shutterstock

6. Lethargy and Weakness

Lethargy and weakness are common side effects of certain hormone imbalances: low blood sugar, as seen in diabetes; low production of stress hormones, as seen in Addison’s disease; and a reduced metabolic rate, as seen in hypothyroidism. In some dogs, it can occur as sudden onset fatigue and in cases of Addison’s disease, even present as acute collapse.

However, in other dogs, it can be more subtle. It will usually but not always coincide with other clinical signs, such as increased thirst, weight loss or gain, and changes in appetite.

7. Pot-Bellied Appearance

Several conditions can result in a pot-bellied dog. Bloating, fluid distension, worms, and even hypothyroidism can all result in a rotund abdomen. However, a common culprit is Cushing’s disease or hyperadrenocorticism. It results in the overproduction of the stress hormone, cortisol, usually due to a tumor in a part of the brain called the pituitary gland.

Excess cortisol in the body results in increased fat storage and muscle weakness. That leads to increased fat in the abdomen and weaker abdominal muscles, resulting in a pot belly and an indication that the dog’s hormones may be acting up.

fat chihuahua dog
Image By: taro911 Photographer, Shutterstock

8. Change in Coat Color

Certain imbalances of the sex hormones in dogs may cause their fur to change color. While it may be quite a novelty for your dog to go from blonde to brunette or vice versa, sudden changes to their coat could be a red flag for their hormonal health. Hypothyroidism can also cause changes to a dog’s coat, including in pigmentation.

That said, a change in coat color can be normal as a dog ages, especially after they shed their puppy coat. If this isn’t accompanied by other clinical signs, it is likely that you don’t have to worry about there being an underlying health issue.

9. Aggression

Elevated sex hormones can result in aggression. We tend to think of testosterone as being the influencing factor on aggression in male dogs, but recent studies are showing that it is likely a cocktail of hormonal factors that influence canine aggression, such as oxytocin (commonly known as the love and bonding hormone), and vasopressin (the hormone responsible for water retention in the body).

Research continues to progress in this field, and the hope is to have a better understanding of how the aggression trait is made by the body and how it can be controlled in dogs whose lives are negatively impacted because of it.

aggressive dog with excessive saliva
Image Credit: Victoria Antonova, Shutterstock


How Is Hormonal Imbalance Treated in Dogs?

When a specific diagnosis of the hormonal imbalance is achieved by your veterinarian, certain medications and therapies tailored to that disease can be given, whether that is replacing a hormone or stopping the body from producing too much of it.

For example, patients with diabetes will be given daily injections of insulin, dogs with an underactive thyroid will be given a synthetic thyroid hormone to take daily, and dogs with Cushing’s disease will require a medication that reduces the production of cortisol in the adrenal gland. For most of these illnesses, lifelong monitoring and treatment are required.

divider-dog paw


Since hormones play such a big part in the almost miraculous biological workings of the body, when they are imbalanced, it manifests as a wide variety of clinical signs. Hormones are complicated and sensitive molecules and when not functioning optimally, can wreak havoc in the body.

Hopefully, you now feel better equipped to have a chat with your veterinarian about your dog’s hormonal health if they are showing any of these signs.

Featured Image Credit: ALEX_UGALEK, Shutterstock

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