Why Is My Dog Gaining Weight? Top 10 Reasons

If you’ve noticed Fido packing on the pounds lately, perhaps you’ve asked yourself, “Why is my dog gaining weight?” Unfortunately, over half of all dogs in America are overweight, and a whopping 30% are obese. Weight gain in dogs has both medical and non-medical causes, which is why it’s essential to consult with a vet if your pup is gaining weight.

Why Is My Dog Gaining Weight? The Most Common Causes of Weight Gain in Dogs

While a fat, chubby puppy is the epitome of cuteness, once your pup has grown up, obesity can cause serious health problems and will significantly reduce their quality of life. Take a look at the top ten reasons (both medical and non-medical) that can answer the question, “Why is my dog gaining weight?”

1) Poor Diet

Just like people, dogs that overeat will gradually gain more weight. If you eat a diet high in carbs, fats, and sugar, you’ll inevitably pack on the pounds, and the same goes for your dog. While dogs of any age can gain weight from overeating, older dogs are particularly susceptible. 

As your dog ages, be sure to make the necessary dietary changes to account for a slower metabolism. If your dog is underweight, you can also try this weight gainer for dogs by XDOG.

2) Lack of Exercise

Regardless of breed, every dog needs regular exercise to stay healthy and in shape. If you take your dog for long walks every day and the dog is still getting thick around the middle, try adding in an extra half-hour of intense catch or frisbee before heading out.

Once your dog starts getting more fit, you can boost their training regimen even more with a weight vest or dietary supplement to help them build muscle. Try to aim for 20 to 60 minutes of activity with your pup every day.

3) Thyroid Problems

While Irish setters, golden retrievers, and cocker spaniels are the breeds most prone to thyroid disorders, any dog can have this condition. Hypothyroidism is a thyroid hormone condition in dogs marked by an underactive thyroid gland, which regulates metabolism. When the gland is underactive, metabolic rates slow down, causing your dog to gain weight. Dogs with hypothyroidism also have accompanying symptoms in addition to weight gain, including:

•       Frequent shedding
•       Oily, greasy skin
•       Excessive itching
•       Dull, dry coat
•       Decreased appetite
•       Lethargy
•       Panting
•       Skin and ear infections
•       Low tolerance to cold
•       Drooping facial expression

If you see these symptoms in your dog, head to the vet right away for testing. Treatment options include medication, surgery, or radiation therapy.

4) Cushing’s Disease (Hyperadrenocorticism)

Cushing’s disease or syndrome is excessive cortisol in the bloodstream from the adrenal glands, often because of a tumor. This condition is another medical cause of rapid weight gain in dogs, with middle-aged and older pups being more susceptible.

With Cushing’s, the adrenal glands overproduce cortisol, a stress hormone that controls weight, regulates blood sugar levels, and fights infections. Excess cortisol will cause rapid weight gain and other symptoms, such as:

•       Ravenous thirst and appetite
•       Constant overeating
•       Frequent and hard-to-control urination
•       Heavy panting
•       Thinning coat or hair loss
•       Potbelly or enlarged abdomen
•       Low tolerance to heat
•       Skin lesions or bruising

Cushing’s requires lifelong medication management since no cure exists.

5) Too Much Protein

Did you know the effects of too much protein for dogs? If your pooch is eating calorie-dense, high-protein food and not getting enough exercise, they’re going to start putting on weight. 

Unfortunately, most of the high-protein dog food brands out there contain proteins that aren’t easily digestible or bioavailable. When your dog eats protein with low bioavailability, most of it either gets flushed out naturally or stored as fat, which is why it causes weight gain.

Monitor your dog’s diet closely to ensure that you’re not giving them too much or too little protein in relation to their lifestyle and activity levels.

6) Genetics

Some dog breeds are more likely than others to gain weight, meaning that your dog could have a genetic predisposition to chubbiness or even obesity. Here are the dog breeds most prone to becoming overweight or obese. Is your dog on this list?

•       Basset hounds
•       Pugs
•       English springer spaniels
•       Rottweilers
•       Bulldogs
•       Boxers
•       Beagles
•       Shetland sheepdogs
•       American cocker spaniels
•       Cavalier King Charles spaniels
•       Golden retrievers
•       Dachshunds
•       Labrador retrievers

7) Medication

Certain prescription medications can also cause weight gain in dogs, especially when they take them in high dosages or over extended periods. If your pup just started taking a new prescription and is now gaining weight, it’s time to speak to your vet. Here are some common medications that can cause weight gain in canines:

•       Prednisone
•       Megestrol acetate
•       Phenobarbital
•       Glucocorticoids

If it turns out that your pup’s meds are causing an increase in their weight, ask your vet for any alternatives that might not have the same side effect.

8) Parasites

While most parasites cause rapid weight loss, a severe infestation of abdominal or intestinal parasites can cause fluid buildup, resulting in a potbelly or distended abdomen. Usually, parasites are more of a problem in younger dogs and puppies, especially those with a compromised immune system.

9) Diabetes

Diabetes is another common medical cause of weight gain, both for canines and humans. This metabolic disorder disrupts the balance of blood sugar and insulin, resulting in your dog gaining weight and body fat. Common signs of diabetes include lethargy, rapid weight gain or loss, and increased thirst or urination.

10) Pregnancy

Pregnancy is another common reason for weight gain. If your dog is an unspayed female, make an appointment at your vet for a pregnancy test to be sure.

Final Thoughts on Weight Gain in Dogs

Hopefully, we’ve now answered your question, “Why is my dog gaining weight?” We won’t deny it: a roly-poly puppy is probably the cutest thing of all time. However, adult dogs that are overweight or obese can have serious health complications, including heart, kidney, and liver problems.

On the other hand, malnourished dogs can also suffer from health problems. For underweight dogs, XDOG’s weight gainer has pure micronized kosher creatine to help your dog gain weight and build muscle. As a final reminder, always consult with your vet if you notice your dog is rapidly gaining weight or suspect they may have a medical condition.