Just like humans, dogs can gain weight if they eat too much and don’t exercise enough.
However, excess weight can also be caused by things that have nothing to do with food, such as medication, medical conditions, and more. Here are four reasons your pooch might be piling on the pounds.
Cause #1: Undiagnosed Hypothyroidism
Hypothyroidism is a condition in which the thyroid gland doesn’t produce enough thyroid hormone. “You can loosely associate hypothyroidism with the furnace of the pet’s body not burning hot enough,” explains Dr. Michel Selmer, DVM, from the Advanced Animal Care Center in Huntington Station, New York. “When there is decreased thyroid function, that’s when pets gain weight.”
Hypothyroidism slows down the entire metabolism, which in turn leads to weight gain. “Even if a dog has hypothyroidism and its owner cuts calories, the dog will still gain weight since food is not the cause of the weight gain,” Selmer explains.
Cause #2: You’re Feeding the Wrong Food
As your pet gets older, it’s important to switch to a different type of food that provides the right balance of fats/carbohydrates/proteins so your dog has enough energy but doesn’t gain weight. “Nutritional requirements are different for a puppy versus an adult dog versus a senior dog,” says Selmer. “Food should be adjusted based on the life stage and activity level of the pet.”
Rules, however, vary from one pet to the next. For example, Selmer says an adult or senior dog should only be placed on lower calorie diets if in fact they are less active. “Caloric intake should be partially based on activity level of the dog as well as its life stage,” he explains.
Another important factor? Always choose high-quality foods. “The closer we can get to human grade foods, the better it is for our pets, provided it is nutritionally-balanced by a licensed veterinarian,” Selmer adds.
Cause #3: Water Retention and Bloating
Cushing’s disease—an endocrine disorder that causes an increase in cortisol production—can cause weight gain due to bloating. “This might not always translate into a real larger number on the scale but the dog will appear bigger,” Selmer says. “With Cushing’s disease, dogs lose muscle mass, which means the scale often stays the same but you will see a skinny dog with a big potbelly who is losing hair.” A dog suffering from Cushing’s disease may also exhibit skin problems, be thirsty and urinate excessively.
Other health issues, including heart disease and cancer, can also cause bloating. “For example, with heart disease, a dog’s heart is not functioning properly to effectively pump blood through the body—this causes fluid to leak through vessels and into the abdomen and/or the chest,” according to Selmer. “This in turn makes the belly expand and looks like the animal has gained weight.” This is dangerous because diseases that can cause dogs to look like they gained weight can be life threatening or life shortening, Selmer explains.
Cause #4: Prescription Drugs
A number of prescription drugs can cause weight gain, especially if given for long periods of time. “For example, Prednisone can cause weight gain because it mimics Cushing’s disease when given for too long or in too high dosages,” Selmer explains.
The solution? If your dog is gaining weight due to medication, your vet might look into switching to a different drug or trying a different approach. “If a veterinarian sees negative side effects, they should look for alternative modes of therapy or different philosophy of care, such as Traditional Chinese Veterinary Medicine,” Selmer says.