Why Is My Dog Losing Weight?

A lot of activity can make dogs lose weight. While it’s not usually common for dogs to lose a few pounds even when eaten healthy, it’s a red flag if you notice your dog is looking a bit different from before. If your dog is losing weight while having a good eating habit, then you should visit your veterinarian.

Dogs have several reasons to lose weight, it can be from daily activities and burn a lot of calories like how humans workout. But if it’s a rapid weight loss, it’s a sign for a health condition.

why is my dog losing weight

Weight loss tends to be very concerning if it exceeds more than 10% of your dog’s normal body weight. If you find that your dog is experiencing weight lose like this we recommend taking Rover to see the vet as soon as possible. Now, anything less than 10% is considered clinically significant, but still should be monitored just in case it gets serious.

Keep reading to find out what can cause your dog to have sudden weight loss and how to solve that problem.

Why Would My Dog Start to Lose Weight?

It’s completely normal for dogs to lose their weight over time. Factors such as age, diets, breed, and activities can affect your dog’s weight. If you’ve noticed your pooch has lost weight even when eating constantly, please call a veterinarian.

Here are common causes your dog is losing weight:

  • Inadequate or poor quality diet.
  • Excessive loss of nutrients – vomiting, excessive urination or diarrhea
  • High energy associated with excessive physical activity or exposure to cold environment to generate body heat.
  • Maldigestion or malabsorption disorders (a decreased difficulty to absorb and digest food).
  • Insufficient intake of food (lack of appetite), difficulties in swallowing.
  • A hypermetabolic which burns calories from the body at a faster due to illness.
  • Color and volume of the stool are unusual.

What Are Some Common Diseases That Cause Weight Loss?

Many diseases can cause the sudden weight loss of your pet. Most chronic diseases are responsible for several weight loss. However, here are some of the common diseases that associate in weight loss:

  • Pseudo anorexia – inability to chew food, loss of smell, or vomiting.
  • Swallowing disorder
  • Nervous system disease causing anorexia and depression.
  • Anorexia (lack of appetite) due to health problems.
  • Metabolic disorder such as cancer, diabetes mellitus and hyperthyroidism.
  • Major organ disease ( Heart, kidney or liver)

Dietary Changes

Not all weight loss is because of diseases or a health problem, it can also be the constant change of your dog’s meal. It might not be exactly the changing of the meal because you have done it for years, but the manufacturers change the formula.

The food that you give your dog now might have 10% fewer calories than what it was before. At the end of the day, your dog eats fewer calories without you even knowing. You could check the calories amount and increase the amount you feed it for more calories.


Diabetes is a disease that is common to older dogs, especially females. They begin to rapidly lose weight since they cannot get energy from broken glucose, instead, their body would depend on converting protein or fat to energy.

If your dog is elderly, you should take them to the vet for daily checkups. Dogs with diabetes lose weight quickly as well as muscles, which makes them weak. Diabetes causes excessive quench, so even if your dog is potty trained, they would have an excessive urination and may have little accidents in the house.

The most common symptoms of diabetes in dogs are:

  • Cloudy eyes
  • Weight loss
  • Excessive urination
  • Excessive thirst
  • Chronic infection

If you notice your dog is experiencing any of these symptoms, please call or visit your nearest veterinary immediately. The case is very serious and if not taken care of immediately, it can be fatal for your dog. Treatments would include shots and better diet plan.

Intestinal Parasites

Dogs are prone to get intestinal parasites from different areas, although this isn’t usually common to weight loss, it is still possible that it’s the cause. Although many dog owners are up to date with their deworming treatment against parasites, not all the methods affect the parasites that live in your dog’s intestine.

For instance, the whipworm is an intestinal parasite that many treatments cannot kill. It can be consumed if your dog ingests eggs that are found in soil or contaminated water.

Either than weight loss and severe sickness, intestinal parasites can cause the following symptoms to your pet:

  • Vomiting
  • Dehydration
  • Diarrhea
  • Abdominal swelling
  • Increase of gas

Fortunately, intestinal parasites can be easily diagnosed and be treated successfully within a month or two.

Kidney Disease

The body of a dog works with age and diets. The older the dog gets, the weaker its organs become, being prone to disease easily. Dogs with kidney disease do not start to lose weight immediately, but does depending on how advanced the kidney disease is. Dogs are able to experience chronic kidney failure which is caused by illness, dental disease or hereditary.

The most common kidney problem signs you would notice from your dog include:

  • Excessive urination
  • Vomiting
  • Diarrhea
  • Constipation
  • Weight loss
  • Lack of activity
  • Palm gums
  • Excessive thirst

Kidney disease is a life threating condition and should be attended to whenever you notice these symptoms from your dog. The treatment of their kidney depends on the dog’s symptoms and the condition of the chronic disease.

Heart Disease

Like with the kidney disease and the liver disease, the heart can also slow down the more the dog ages. It doesn’t start weight lost immediately, similar to the kidney disease.

Since heart disease can lead to a congestive heart problem, here are symptoms that dog experience with early stage heart disease:

  • Coughing
  • Restlessness
  • Breathing difficulties
  • Tired easily
  • Lack of activity
  • Excessive panting

As the heart disease begin to progress, the symptoms begin to change:

  • Weight loss
  • Fainting
  • Swollen belly
  • Built in gas or fluids
  • Color change of gum and tongue.

Heart disease is a serious situation and should be taken seriously, it’s very crucial to take your dog to the veterinarian as soon as you notice any of the given symptoms. If the disease is diagnosed during early stages, it can be treated and your dog is able to get back on its feet again.

What Kind of Treatment is There for Weight Loss in Dogs?

Once you have called your veterinarian to check on your dog, treatments would be given determined by the situation of the dog’s weight loss. For any diagnosis, a special treatment would be given to your pooch until fully recovered.

Sudden weight loss in dogs is never normal and should be checked before it becomes a serious health problem. Always check for any unusual behavior and have your vet’s number on speed dial. It’s important we help our furry friends to be in good health.

If you have any questions about your dog’s weight and overall health, give us a call! We are here when you need us.

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At Parkway Veterinary Emergency Clinic, our team consists of experienced veterinarians and veterinary professionals dedicated to providing exceptional after-hours emergency vet care to the pet community of Lakeland.