9 Signs of Hormonal Imbalance in Dogs

Symmetrical Hair Loss

Hair loss (“alopecia”) is commonly associated with various hormonal imbalances. The pattern of baldness differs from other causes, such as skin diseases and injuries, in that hair loss often occurs on both sides of the body and is symmetrical. In contrast, skin conditions, including parasites and allergies, typically result in irregular, patchy hair loss. Symmetrical hair loss, especially when accompanied by other signs, often raises concerns about potential endocrine issues. Usually, once the underlying condition is treated, hair regrowth resumes.

Frequent Urination and Thirst

When a veterinarian asks about changes in a pet’s thirst and urination habits, it is usually to help confirm or rule out specific conditions. The medical terms for increased thirst and urination are “polydipsia” and “polyuria,” which can indicate possible disorders related to hormonal imbalances, such as Cushing’s disease or diabetes. If there are changes in your dog’s drinking and bathroom habits, the next step is typically a urine analysis and blood test to check for any underlying condition.

Increased or Decreased Appetite

Changes in appetite can be signs of several hormonal imbalances. Dogs with diabetes may exhibit an insatiable appetite, as their bodies are unable to transport glucose into cells due to insulin deficiency (a hormone needed to move glucose from the bloodstream into cells). Despite eating, the body remains in a state of starvation because the cells lack energy. On the other hand, dogs with hypothyroidism may show a reduced appetite. If there are any changes in your dog’s appetite, even if they seem hungrier than usual, it’s important to consult a vet, especially if it’s associated with other symptoms.

Weight Loss or Gain

Hormones directly influence metabolism. An overproduction or underproduction of thyroid hormones can cause metabolism to speed up or slow down. When not enough thyroid hormone is produced, metabolism slows down, potentially leading to weight gain even if the appetite decreases. Conditions like diabetes can lead to significant weight loss despite an increased appetite. Sudden, unexplained changes in weight, not related to dietary changes, warrant concern.

Dry or Flaky Skin

Signs of hormonal imbalance can also appear on a dog’s skin. One function of reproductive hormones is to stimulate the sebaceous glands in the skin. When sex hormones are low, the skin may become dry and flaky. The same applies to hypothyroidism. When metabolism is disrupted, sweat glands are also affected, leading to dry skin. If your dog has dry, flaky skin, it’s advisable to consult your vet about potential hormonal issues.

Lethargy and Weakness

Lethargy and weakness are common side effects of certain hormonal imbalances: low blood sugar in diabetes, reduced production of stress hormones in Addison’s disease, and slowed metabolism in hypothyroidism. For some dogs, this may manifest as sudden fatigue, and in cases of Addison’s disease, even acute collapse. For others, it may be subtler. These signs often coincide with others, such as increased thirst, weight changes, or altered appetite.

Abdominal Enlargement

Conditions like bloating, swelling, parasites, and even hypothyroidism can cause the abdomen to become rounded. A common culprit is Cushing’s disease, or hyperadrenocorticism. This leads to an overproduction of the stress hormone cortisol, often due to a tumor in the pituitary gland. Excess cortisol in the body leads to fat accumulation and muscle weakness. This results in a thicker fat layer in the abdomen and weakened abdominal muscles, giving the dog a pot-bellied appearance, signaling that hormonal imbalances may be at play.

Coat Color Changes

Certain imbalances in reproductive hormones can cause changes in a dog’s coat color. Sudden changes in their coat may be a warning sign of hormonal health issues. Hypothyroidism can also cause changes in a dog’s fur, including pigmentation. However, coat color changes may naturally occur with age, especially after shedding puppy fur. If this isn’t accompanied by other symptoms, it’s likely not a cause for concern regarding health issues.

Aggression

Elevated levels of sex hormones can lead to aggression. Testosterone is a factor in male dogs’ aggression, but research suggests that a combination of hormonal factors, such as oxytocin (the hormone of love and bonding) and vasopressin (the hormone responsible for water retention in the body), likely influences canine aggression.