Why Is My Dog Gaining Weight?

why is my dog gaining weight_canna-pet

A lot of owners pride themselves on having fit or lean dogs. It demonstrates responsibility, respect for your pet, and proper care. But sometimes your dog’s weight gain is out of your control, and despite keeping your dog on a strict diet and exercising him frequently, the number on the scale keeps getting higher. Just as frustrating as your personal weight gain, it can be discouraging when you don’t know where the weight is coming from.

The thing is, not all weight gain can be attributed to exercise and diet. Oftentimes when your dog is gaining weight at a significant rate, there is an underlying health condition. So instead of monitoring your dog’s food intake down to a science and running him until he’s dead tired, learn more about other potential causes of weight gain in dogs.


Though this may sound like an obvious one, some dog pregnancies go completely undetected by their owners. If your dog is not spayed, it only takes a few minutes of being left alone outside with an unneutered dog to end up pregnant.

Most dogs are spayed or neutered at eight weeks, so this is less of a concern for typical dog owners. However, if you leave your dog unneutered for personal or breeding purposes, be sure to keep close watch of your pup when she is around other dogs.

Fluid Retention

dog gaining weight_canna-pet

A very common side effect of heart disease is a condition called ascites, a term used to describe excess fluid in the abdomen. The most telling physical symptom is an enlarged belly unaccompanied by overeating or lack of exercise.

Other conditions such as tumors or diseases of the internal organs also cause a high amount of fluid retention. Specifically, in very young dogs, abnormal amounts of fluid in the abdomen can be a result of insufficient blood flow to the heart due to a congenital defect.

Chronic Illness

Chronic conditions such as Cushing’s syndrome are also associated with weight gain. This condition is most common in older dogs and causes them to have an increased appetite, increased drinking and urinating, skin lumps, hair loss, muscle weakness, or nervous systems disorders.

With this plethora of symptoms, you want to be sure to get a medical diagnosis before assuming that your dog has Cushing syndrome. Left untreated, the disease can progress and lead to life-threatening disorders such as diabetes, congestive heart failure, liver failure, and kidney failure in dogs.

Another chronic illness to be aware of is hypothyroidism. Certain breeds such as Doberman Pinschers and Golden Retrievers are more prone to hypothyroidism. Symptoms of hypothyroidism in dogs include lethargy, hair loss, weakness, infection and less tolerance for exercise.

The good news about hyperthyroidism is that it is easily treated with hormone replacement therapy. While you wont be able to cure your dog from the condition, medication can regulate his hormone levels and cause little to no interference in his every day life.


weight gain in dogs_canna-pet

Internal parasites, specifically those that house themselves in the abdominal walls and intestines, will often cause fluid build up in the abdomen. Parasites are most common in younger puppies whose immune systems are not yet fully developed, so you want to keep a close eye on your puppy’s physical appearance as he starts to grow and mature.

The most common physical sign of a parasite is a potbellied stomach. Although, parasites will need to be further identified through blood, fluid or stool samples, they can be easily treated with prescribed medication.


Dogs can experience the same painful side effects from bloating that humans do. Trouble breathing, rapid heart rates, and abdominal cramping are all signs of bloat in dogs.

Dogs typically bloat when they ingest their food too quickly, which causes them to swallow large amounts of air during the process. Breeds with deep chests such as Great Danes, German Shepherds and Standard Poodles are more susceptible to bloating. Ways to lessen bloating would be to give your dog food in smaller servings, which will allow him to digest his food more easily.

With one out of every three dogs in the US being overweight or obese, it is easy to ride off your dog’s weight gain as an inevitable statistic. However, weight gain can be a more telling sign of a serious condition or underlying problem, so it is important to carefully monitor your dog’s behavioral and physical changes.

While the treatment plan may just be a few more walks around the block, it could also be something more serious that requires medical attention and assistance. Instead of putting your dog through your own personal boot camp, be sure to check with a medical professional for appropriate next steps.


Get 30% off When You
Join Our Newsletter

Sign Up Today
  • This field is for validation purposes and should be left unchanged.