Why My Dog Is Losing Weight But Eating – Top Reasons

It’s not unusual for dogs to lose a few pounds once in a while, but any sudden and unexplained weight loss should raise red flags for all dog owners. Visit your veterinarian if your dog is losing weight but eating. 

A dog’s weight loss can be caused by many factors, just as it is in people. Rapid weight loss may indicate serious underlying health problems. There is also the possibility that your dog is more active and burning more calories than before. 

A dog’s weight loss of more than 10% of its normal body weight should raise serious concerns and warrant a visit to the veterinarian.

You should monitor your dog’s weight and keep an eye on them if their weight is below 10%.

Schedule an appointment with your vet if your dog continues to lose weight for no apparent reason. 

It’s very stressful to watch as your dog’s weight disappears in front of your eyes without any apparent cause!

Being overweight is a problem for many dogs, but being emaciated is just as serious and should not be ignored.

Discover why dogs suddenly lose weight and what can be done to prevent it in the following paragraphs. (1)

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Top 5 smartest Dog Breeds

Why is my dog so skinny even though he eats?

During your dog’s lifetime, it is completely normal for its weight to fluctuate. Your dog’s weight can be affected by factors such as diet, breed, and age. You should, however, speak to your veterinarian as soon as possible if your dog continues to lose weight despite eating well. 

There are many reasons why dogs may lose weight, but losing weight without a diet is not normal. Even if your dog has a healthy appetite, don’t be alarmed if he suddenly loses a lot of weight. You should instead take your dog to the vet so they can diagnose the problem and provide the proper treatment. 

The following are the most common reasons for your dog losing weight but eating:

Intestinal Parasites

It is still possible to lose weight due to intestinal parasites, even though they are not as common as they once were. 

There are many different types of intestinal parasites, and not all deworming treatments are equally effective. Dog owners typically regularly deworm their dogs on a monthly basis, which offers protection against intestinal parasites and heartworms.

The eggs in contaminated water or soil can infect your dog, and many treatments can’t kill whipworms. (2)

Intestinal parasites deprive dogs of all essential nutrients since they consume all the food they eat. Your dog may be suffering from intestinal parasites if he eats a lot but loses weight. 

These symptoms can also be caused by intestinal parasites: Diarrhea, Increased gas, Abdominal swelling, Vomiting, Dehydration.

A fecal examination can diagnose intestinal parasites, which are treated with broad-spectrum dewormers. Deworming medicine should be taken monthly after successful treatment. 


The body cannot absorb nutrients from the intestinal tract when it has malabsorption disorders. One of the most common malabsorption disorders in dogs is inflammation of the bowel. (3)

Dogs with inflammatory bowel syndrome may eat a lot, lose weight, vomit, have diarrhea, or have foul-smelling loose stool. This disease causes inflammation of the intestines, but its cause isn’t completely understood. 

Fecal examinations, blood tests, and X-rays or ultrasounds of the intestines are the initial tests for inflammatory bowel disease.

Currently, there is no cure for this disease, but it can be treated with a specialized diet, probiotics, and anti-inflammatory medications. Even though inflammatory bowel disease is a chronic condition, your dog can still lead a normal life with the right diet and treatment. 


In older dogs, in particular females, diabetes is often diagnosed. Diabetes causes dogs to lose weight rapidly since their bodies cannot convert glucose into energy and instead attempt to turn fat or protein into it.

A veterinarian should be consulted if your older dog is losing weight but eating and drinking plenty of water. In diabetic dogs, weight loss is rapid, and muscle mass is often lost as well. 

In addition, since diabetes causes excessive thirst, your dog may also have accidents in the house even if he is properly housebroken. 

Diabetes in dogs is most often characterized by: Weight loss, Excessive urination, Excessive thirst, Cloudy eyes, Increased appetite, Chronic or recurrent urinary infections.

If your dog exhibits any of these symptoms, you need to take them to the veterinarian immediately.

In order to determine whether your dog has diabetes, your veterinarian will run a blood glucose test and a urinalysis. In the event that diabetes is diagnosed, insulin shots and a specialized diet will be prescribed. 

Dietary Changes

Weight loss is not always caused by disease. Changing your dog’s food can lead to significant weight loss, as is changing its environment. 

Since I haven’t changed my dog’s food in years, you may think that this can’t be true. However, even though your dog may be eating the same brand of kibble, the manufacturer may have changed the formula. 

Continuing to feed your pup the same amount of dog food as before, you are unaware that the new formula is 10% less calorific. Ultimately, your dog eats fewer calories than it needs and, as a result, starts losing weight sooner or later. 

Due to the confusing way many dog foods are labeled, these changes are easy to miss. You should check the food’s ingredient label and see how many calories it has per serving before you assume that your dog is sick. 

Schedule an appointment with your veterinarian if the food is the same as before. You should feed your dog more of the formula if it turns out that it has fewer calories. 

Also Read: Top Reason Why dog leaves odorless wet spot

Kidney Disease

Your dog’s organs become less efficient as it ages. A dog with kidney disease does not lose weight right away, even though weight loss is a symptom of many conditions. A dog with advanced kidney disease typically loses weight slowly. 

Chronic and acute kidney failure can occur in dogs. Usually diagnosed in older dogs, the latter disease progresses slowly over time. An underlying illness, hereditary conditions, and dental problems can cause chronic kidney disease. 

Dogs with kidney problems typically exhibit the following symptoms: Excessive urination, Increased thirst, Pale gums,  Diarrhea or constipation, Weight loss, Vomiting, Depression. 

When you notice any of these symptoms, take your dog to the veterinarian immediately. Kidney failure is a life-threatening condition. Whether your dog suffers from acute kidney failure or chronic kidney failure will determine the type of treatment. 

Heart Disease

Heart problems don’t cause dogs to lose weight immediately like kidney disease. As a matter of fact, early symptoms of heart disease in older dogs are so subtle that most owners attribute them to the normal aging process. 

Congestive heart failure can be caused by heart disease, so you should know the symptoms so you can provide your dog with the help they need. 

Here are some symptoms your dog may experience if they have early-stage heart disease: Exercise intolerance, Tiring easily, Excessive panting, Restlessness, Coughing.

When your dog’s heart disease progresses, more symptoms may appear, including Fainting, Change in tongue and gum color, Swollen belly due to fluid build-up, Weight loss. 

If you notice any of these symptoms, you should take your dog to the veterinarian right away. With proper care and regular checkups, your dog can live a long, normal life and have a normal, happy life even if it is diagnosed in the early stages of heart disease. 


Food into usable nutrients is hampered by maldigestion disorders, including exocrine pancreatic insufficiency. As a result, your dog’s digestion system does not absorb all the essential nutrients he consumes every day.

Despite a healthy appetite, a dog with maldigestion disorder will continue to lose weight. Your pooch may also suffer from diarrhea, loose yellow stools, and gas in addition to the noticeable weight loss. These symptoms alone are not enough to diagnose the problem.

Therefore, you should take your dog to the veterinarian for a full physical examination and tests. A stool sample and a blood test for digestion enzymes will be taken by your veterinarian. 

Dental Disease

Senior dogs often suffer from dental disease. A dog with broken or infected teeth, gingivitis, or gum disease will have difficulty eating due to the pain. 

Many dogs stop eating their food because dental problems make chewing painful. However, even dogs who aren’t experiencing severe oral pain will lose weight if they cannot chew properly because of their pain. 

Common dental symptoms include the following: Difficulty eating and chewing, Excessive drooling, Swollen or bleeding gums, Bad breath.

Take your dog to the veterinarian for a dental examination if it is losing weight or showing any of these symptoms. Dental disease can affect your dog’s heart, liver, and kidneys if it is not diagnosed and treated in time. 

Fortunately, dental disease is fairly easy to treat if spotted early enough, and most dogs are able to eat normally once it is treated. You should brush your dog’s teeth from a young age since dental problems can affect your dog’s overall health. 

Liver Disease

Your dog’s weight loss may also be caused by liver disease, a common condition in dogs. It’s hard to recognize liver disease until it’s too late because the symptoms are similar to those of other health problems.

Liver disease is usually caused by aging, but it can also be caused by an infection, fatty food, and certain plants or medications.

Dogs with liver problems can also exhibit the following symptoms in addition to their weight loss: Increased thirst, Vomiting, Diarrhea, An unstable walk, Confusion, Jaundice – yellowish eyes, tongue, or gums.

In addition to older dogs, young dogs can also suffer from liver disease. Take your dog to the veterinarian as soon as possible if they are losing weight and experiencing any of these symptoms. The treatment your dog will receive will depend on the severity of the liver damage and its cause.


You can lose weight despite your dog eating the same amount as usual if your dog suffers from cancer. Cancer in dogs can take many forms, and some of them do not cause symptoms until they have spread. 

Cancer tends to affect older dogs, but it can also strike young and adult dogs. It is possible to die from malignant forms of cancer, even when detected early and treated aggressively. 

Weight loss is associated with several cancers in dogs, such as osteosarcomas, hemangiosarcomas, and lymphomas.  The tumor’s metabolic demands may cause a dog to lose weight, or the dog may not be able to eat due to pain. (4)

Even though it’s hard, do not assume that your dog’s weight loss is caused by cancer! You should take your pup to the veterinarian for a full checkup if he seems to be losing weight.

Consult your vet about all available treatment options if your dog is losing weight because of cancer and do what’s right for him in the long run. (5)

Metabolic Disorders

Your pet’s body condition can be affected by metabolic disorders such as hyperadrenocorticism (Addison’s disease) and diabetes mellitus.

Identifying metabolic conditions may require advanced diagnostic testing because these conditions often display complicated clinical signs. 

Also Read: Why Is female dog leaking clear odorless fluid?

Gastrointestinal Disorders 

Over time, excessive vomiting and/or diarrhea can lead to weight loss in dogs, as they find it difficult to retain nutrients. (6)

There are various causes for diarrhea and vomiting, which is why you should consult a veterinarian to determine what is causing them. 

Malabsorption or maldigestion affects the intestines’ ability to digest and absorb nutrients. Until a medical solution is found, pets with gastrointestinal disorders will be underweight regardless of how their diet is altered. (7)

why is my dog so skinny even though he eats


What Is the Reason My Dog Is Getting Skinny?

Dogs lose weight when they experience a calorie deficit. There are a number of reasons for this, including high energy demands, poor quality food, or health issues. Various conditions can cause sudden weight loss, such as dental problems, intestinal parasites, diabetes, and cancer.  

What Should I Feed A Dog That Is Losing Weight? 

A veterinarian should be consulted if you have an underweight dog in order to rule out any potential health problems. Your veterinarian will advise you on what course of treatment to give your dog if he or she has a health problem, as well as what you should feed him to help him gain back weight. (8)

Feed your dog more calories if you want to fatten him up. Make sure the food you buy is made of healthy and wholesome ingredients, and choose the best quality you can afford.

Aside from feeding four smaller meals throughout the day, you can help your dog gain weight by giving him four smaller meals each day.

As dog’s age, do they lose weight?

It is true that the metabolic rate of your dog changes as it ages. A mature dog actually needs about 20% fewer calories to maintain its weight than a younger dog. 

Therefore, as your dog ages, you will want to feed him dog food that is specially formulated for older dogs, as it has fewer calories and fat. 

It is very normal for a dog to lose weight as it matures from old to very old. You may find that your senior dog has a decreased appetite as a result of the lack of smell/taste, or they may have difficulty chewing or swallowing. 

Your older dog may need a higher fat diet if they are losing weight but eating.  If this is the case, you’ll need to increase their food’s fat content and calorie count in order to make every bite count.

When My Dog Loses Weight, What Should I Do?

Your veterinarian is the best person to contact. An expert can assess the condition of your dog’s body and rule out any conditions that may be affecting its weight.

If Your Dog Is Losing Weight, Should You Visit The Vet?

There are similar warning signs or symptoms associated with many common causes of weight loss. To determine whether you need to take your dog to the veterinarian, you should evaluate the possible causes of the symptoms and weight loss.

Also Read: Why does my Dog scabs on nipples?

How Many Times A Day Should You Feed A Dog? 

Generally, adult dogs should eat twice every day – once in the morning and once at night. Puppies under the age of five months must be fed three or four smaller meals a day or as instructed by your veterinarian.

Each dog is unique, so how often they should eat will vary according to their age, size, breed, and activity level.  

Do You Know If Your Dog Is Too Thin?

Taking your dog to the veterinarian is the best way to find out if they are too thin. The vet can evaluate your dog’s body condition score. According to the World Small Animal Veterinary Association, a healthy dog weight has a body conditioning score of 4 or 5. 

When looking at your dog, Tufts University’s Veterinary School states that if you can see the ribs, lower back vertebrae, and pelvic bones, then your dog might be too thin, and you should take them to the vet for evaluation. You can feel the ribs of a healthy dog, but not necessarily see them. 

Supplements and treats made by Rogue Pet Science contain Omega-3 fatty acids, as well as other essential vitamins that contribute to the health of pets.

Why Is My Dog Losing Weight And Drinking Lots Of Water?

There are many different health problems that can cause weight loss and excessive thirst. If your dog exhibits any of these symptoms, please visit your veterinarian as soon as possible.

Dogs with kidney failure, diabetes, or Cushing’s disease may exhibit these symptoms. Dogs of all ages can suffer from acute kidney failure, but they are more likely to develop the condition in older dogs. 

Moreover, increased water consumption can indicate dehydration, so make sure that your dog always has access to fresh, clean water. 

Can walking a dog help them lose weight?

In addition to following a veterinarian’s diet recommendation, walking your dog is very important for weight loss. Approximately 30 minutes of daily walking is recommended. 

Listen to your dog’s breathing to determine how fast you should walk if your dog is severely overweight. Slow down or take a break if your dog’s breathing becomes labored. Build up to 30-minute walks over time.

Also Read: Why is my dog scared of me And What Should I do?

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