Common Dog Illness: Obesity and Its Causes

Sometimes a little extra pudge on your pup is cute right? While it may seem endearing to watch their stomach sway as they walk, it shouldn’t be seen as a good lifestyle. Obesity in dogs can lead to serious health complications and physical ailments. The sad part is that overweight dogs are a very common problem. 

Association For Pet Obesity Prevention (APOP) found that 59.5% of cats and 55.8% of dogs classified as overweight or obese in America. That means an estimated 56 million cats and 50 million dogs are overweight or obese. 

The problem isn’t isolated to the U.S. alone: international research suggests that 40% of dogs all over the world are obese. 

What’s even worse is that around 95 percent of owners don’t realize that their dogs need to lose weight. 

If your dog is one pound overweight, chances are it won’t affect your dog’s overall health. You should worry when they’re significantly overweight for their breed. Think about it this way, adding 5 pounds on to your 5-pound pomeranian is literally doubling their weight and putting them over the healthy average weight for the breed. In comparison, that same five pounds may not be as seen or felt on your 80-pound male German Shepherd. 

Talk with your vet or do research on what weight is considered to be healthy for your dog. Consider the following: 

  • Breed
  • Age
  • Gender
  • Average activity

All of those play a role in what is a healthy weight for your dog. 

Why is Obesity in Dogs a Bad Thing?

Obesity can cause severe health problems! There are many diseases and conditions that can develop if your dog is overweight for a long period of time. Common conditions that can develop due to obesity in dogs include type 2 diabetes, osteoarthritis, high blood pressure, skin disease, heart and respiratory problems, and decreased life expectancy (by up to 2.5 years). 

Physically, more pounds on your dog means they’re more likely to injure their hips, knees, elbows, and ankles. For example, your dog is more likely to tear their CCL (cruciate cranial ligament) because extra weight means more strain on their knees. 

What Causes Obesity in Dogs?

The obvious answer is that you’re overfeeding your dog, but sometimes it’s more than just giving them a tasty treat from the table after they’ve already eaten. 

The biggest cause is actually a lack of physical activity — just like in humans! They can eat a balanced diet and still be overweight if they don’t have the activity to shed off the pounds. In other words, dogs can be obsese if they eat more calories than they expend. 

Old age can also cause obesity. As dogs get older, they slow down — their physical activity gets less and less and their metabolism can’t keep up like it used too. Sound familiar? The same thing happens to humans. 

Other causes of obesity include:

  • Hypothyroidism
  • Insulinoma
  • Hyperadrenocorticism (Cushing’s Disease)
  • Neutering


Hypothyroidism is a condition caused from a lowered production and release of T4 and T3 hormones by the thyroid gland. 

It’s more common in medium and large dog breeds, like doberman pinschers, Irish setters, golden retrievers, boxers, poodles, and cocker spaniels. Age also plays a role in diagnosis: most dogs are between the ages of 4 and 10 when the condition develops. 

Symptoms include the following:

  • Lethargy
  • Generalized weakness
  • Unexplained weight gain
  • Hair loss
  • Poor hair growth
  • Excessive dry skin
  • Recurring skin infections


Also known as pancreatic cancer, insulinoma is a serious condition that can lead to weight gain. The name comes from the insulin that is produced by the cancerous beta cells called insulinomas. 

This condition is severe and can be fatal, so take your dog to the vet right away if you notice any of the following symptoms: 

  • Physical collapse/loss of consciousness 
  • Seizures
  • Extreme weakness
  • Neurological abnormalities
  • Abnormal weight gain

Hyperadrenocorticism (Cushing’s Disease)

Cushing’s Disease, also known as hyperadrenocorticism, occurs when your dog’s body produces too much cortisol. Cortisol is a hormone that helps individuals respond to stress and modulates the immune system in regular amounts, but too much in the body can do a lot of damage.

Hyperadrenocorticism in dogs generally affects middle-aged to older animals. At any age, taking high levels of steroid dog medications or taking these medications for a long time can cause the same symptoms.

Symptoms of Cushing’s Disease include:

  • Increased thirst and urination 
  • Urinating at night or having accidents
  • Increased hunger
  • Increased panting
  • Pot-bellied abdomen
  • Obesity
  • Fat pads on the neck and shoulders
  • Loss of hair
  • Lack of energy
  • Muscle weakness
  • Infertility
  • Darkening of the skin
  • Thin skin
  • Bruising
  • Hard, white scaly patches on the skin, elbows, etc. 

If you’re worried that your dog’s obesity is caused by something more than a high caloric diet, or if you want to get them on diet, contact your vet or call Acoma Animal Clinic in Tucson for advice on where to begin. 

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