6 Medical Reasons Why Your Dog May be Overweight

6 Medical Reasons Why Your Dog May be Overweight

Health & Safety

You may have noticed that your dog has put on some weight and knowing how bad it can be for your pet's health acted accordingly by watching what you give them to eat as well as upping their exercise. However, the weight just does not seem to be dropping off and it seems like they are actually putting the pounds on even though they're on a diet. This could be a cause for concern because if more exercise and a well planned diet hasn't done the trick, your dog could be gaining weight due to a medical condition.

Below are six medical reasons why your dog may be putting on weight rather than losing it which would need to be confirmed by a visit to the vet.

It Could Be Fluid Retention

One of the most common side-effects of heart disease is called ascites which is a medical term for when excess fluid is retained in the abdomen. The visible symptom of the condition is a swollen and distended belly. However, other reasons why the body might retain fluid could be due to a tumour or other diseases that affect internal organs.

Fluid retention in puppies could be due to an abnormal flow of blood in the heart which could be a congenital defect – this means the pup was born with the condition. Another common cause of fluid retention could well be linked to a portosystemic shunt which is also referred to as a “liver shunt”.

Is Your Dog on Prescribed Medication?

Some prescribed drugs can lead to weight gain and this is especially true if a dog has been on the medication for a long period of time. If this is the case, you would do well to discuss the problem with your vet so they can either prescribe another type of drug or at least reduce the dose of the existing one to prevent your dog putting on any more weight.

Parasites Can be The Cause of Weight Gain

Worms and other internal parasites that lodge themselves in the abdominal wall and intestines are often the cause of fluid building up where the infestation is worse. This often makes a dog seem pot-bellied and is more apparent in younger dogs and puppies where the immune system is not as strong as it should be. Your vet should be able to do some simple blood and fluid tests as well as take stool samples to determine which parasites, if any are causing the problem and then prescribe the correct wormer to treat your dog.

Hypothyroidism Could Be Causing the Weight Gain

Just like humans, dogs may suffer from thyroid imbalances. Thyroid glands control how the body uses energy which in brief means they are in charge of how fast energy is metabolised. Food provides the source of energy for all living things and if everything is working normally, the body manages to burn off the energy consumed during the course of the day. However, when thyroid glands don't work as they should and the metabolism is sluggish, too much energy is stored in the body which results in weight gain.

Hypothyroidism is the name given for this condition and the chances are if your dog is suffering from it, you will be at a loss as to know why they are putting on weight when you have put them on a strict diet. The reason is that no matter how little your dog eats, this will be stored rather than used up via the metabolic process.

Other symptoms associated with the condition and which you should watch out for are as follows:

  • Fatigue
  • Coarse hair coat
  • Slow heart rate
  • Dry and itchy skin

Your vet should be able to establish if your dog is suffering from this disorder by performing some simple blood tests and if the results come back positive, will prescribe the right medication for your pet to take in order to treat the condition.

Cushing's Disease Can Cause Weight Gain

The medical term for this condition is Hyperadrenocortiscism and it's a disorder often seen in older dogs. The condition first starts by a long-term overproduction of a hormone called glucocorticoid. The hormone is associated with the adrenal glands and the pituitary glands and appears when there is something abnormal going on in either of these.

When it's the pituitary gland that's causing the problem, the chances are there is a tumour forming in the gland which causes it to produce too much ACTH. However, if it's the adrenal gland causing the problem which is rarer, then an over production of a steroid hormone called cortisol is present.

The symptoms often associated with Cushing's which you should watch out for are as follows:

  • Muscle weakness and wasting
  • Extreme thirst
  • Increased appetite
  • Urinary tract infections
  • Rapid weight gain
  • Hair loss

The most visible symptom is a pot belly which is caused by weakening muscles in the abdomen and fats building up there. If you are concerned that your dog may be suffering from Cushing's you would need to have a vet to examine your dog and then correctly diagnose the condition which can be achieved by taking blood and urine samples together with other necessary tests.

Bloat a Life-threatening Condition

Often when dogs wolf their food it can cause them to gulp down too much air at the same time which causes a condition known as bloat. Their stomachs are full of food that's not been chewed properly and a lot of excess air – the result is what is called gastric dilatation and volvulus syndrome (GDV) – otherwise known as bloat. The result is that your dog may have trouble breathing, suffer a rapid heartbeat, they may drool and their abdomens are painful and tender. In some cases, dogs will collapse when suffering from bloat.

Bloat may sound innocuous but the reality of the condition is that it is life-threatening and any dog suffering from it needs to be taken to the vet immediately. Bloat is a condition that is seen more commonly in bigger, deep-chested dogs, namely Great Danes and German Shepherds, although Standard Poodles are prone to the condition too.



Pets for studWanted pets

Accessories & services

Knowledge hub


Support & safety portal
Pets for saleAll Pets for sale