Why is my dog so skinny even though he eats? – 5 Reasons why

A dog that stays skinny even though he eats is usually either not getting enough calories for his activity level (too small portions or a low-calorie food) or isn’t absorbing what he eats because of parasites or a digestive problem. Medical conditions such as diabetes or pancreatic insufficiency can also cause weight loss despite a good appetite, so unexplained weight loss always deserves a vet check.

Below we go over the five most common reasons, a few medical causes to know about, and tips to help your dog gain weight safely.

5 reasons your dog is so skinny even though he eats

1Not giving the right amount of food

One common reason why your dog may be losing weight, despite eating, is that they are not getting enough food. If you are unsure of how much to feed your dog, read the packaging of their food. Most of the time, it will give you a guideline of how much to feed based on your dog’s weight.

It is also important to remember that not all dogs are the same; some may need more or less food than others. If you are still unsure, ask your veterinarian for advice. A vet can give advice based on your dog’s weight, age, and activity level.

2Your dog may be more active than normal

Another possibility is that your dog has increased their activity level and is burning more calories than usual. If your dog has started to go on more walks or runs with you, this could be the reason why they are losing weight.

To make sure your dog is getting enough calories, you may need to adjust its food intake. Just increase the amount you are feeding them by a little bit. Our dog calorie calculator gives you a good starting point based on your dog’s weight, activity level and body condition. If you are still unsure, ask your veterinarian for help in determining how many calories your dog needs.

3Low-calorie food

It is also important to note that different types of food have different calorie densities. For example, a cup of dry kibble usually has considerably more calories than a cup of wet food. This means that you may need to feed your dog less dry food than wet food to give them the same number of calories.

Try to find a food that is high in calories and nutrients, so your dog can get the most bang for its buck, so to speak. This will help them to maintain their weight, even if they are eating less food overall.

4Intestinal parasites

Intestinal parasites are another possible reason for weight loss in dogs, even though they are eating. These parasites can steal nutrients from your dog’s food, preventing them from getting the nourishment they need. If your dog has a habit of eating poop, our guide to the best poop eating deterrents for dogs may be useful.

If you suspect that your dog has intestinal parasites, take them to the vet for a check-up. A vet can prescribe medication to kill the parasites and help your dog get back to a healthy weight.

5Not absorbing nutrients

Last but not least, another reason your dog may be losing weight, despite eating, is that they are not absorbing nutrients from their food properly. This can be due to a number of different factors, such as:

1. Intestinal parasites, as mentioned above
2. A food intolerance or allergy
3. An intestinal disorder such as inflammatory bowel disease (IBD)
4. Exocrine pancreatic insufficiency (EPI), where the pancreas doesn’t make enough digestive enzymes. Dogs with EPI are often ravenously hungry but stay thin and pass large, pale, greasy or loose stools.

If you suspect that your dog is not absorbing nutrients properly, take them to the vet for a check-up. The vet can run tests to determine the cause and recommend the best course of treatment.

6Other medical causes to rule out

Weight loss despite a normal or increased appetite can also be caused by other health problems, such as diabetes (often with increased thirst and urination), kidney or liver disease, cancer, or dental pain that makes your dog drop food or chew less. Senior dogs also tend to lose muscle as they age. Your vet can check for these with an exam, blood work and a stool test.

7Some dogs are naturally lean

Finally, keep in mind that some breeds, like Greyhounds, Whippets and many working dogs, are naturally slim, and young, active dogs often look lanky. If your dog has always been lean, has plenty of energy, and your vet is happy with his body condition, a visible outline of the last ribs can be perfectly normal.

4 Tips to help your dog gain weight

If your dog is underweight, there are a few things you can do to help them gain weight:

1Feed them more food

This may seem obvious, but it is important to make sure you are giving your dog enough food. If you are unsure of how much to feed them, ask your veterinarian for advice.

2Choose a high-calorie food

As mentioned above, different types of food have different calorie densities. Choose a food that is high in calories and nutrients to help your dog gain weight.

3Add some healthy fat to their diet

Healthy fats, such as fish oil or a little olive oil, can help to increase your dog’s calorie intake. Start with a small amount and increase slowly, since too much fat at once can cause diarrhea, and high-fat diets can trigger pancreatitis in some dogs. Check with your vet first if your dog has a sensitive stomach or a history of pancreatitis.

4Exercise with them

You may think that exercise would only help your dog lose weight, but moderate exercise can actually help an underweight dog build muscle mass and can boost appetite. Just make sure not to overdo it – too much exercise burns the calories your dog needs to gain weight.

When to see the vet?

If your dog is simply getting more exercise or eating a lower-calorie food, a gradual increase in food may be all he needs. But if your dog is losing weight while eating normally (or even more than usual), or if the weight loss continues after you increase his food, make an appointment with your veterinarian. Don’t wait if the weight loss comes with vomiting, diarrhea, increased thirst or urination, low energy, or a loss of appetite, or if your dog has lost more than about 10% of his body weight. They will be able to give you more specific advice and help you determine the cause of your dog’s weight loss.

Signs that your dog is malnourished

If your dog is malnourished, they may show some or all of the following signs:

• Lethargy
• Loss of muscle mass
• Ribs and hip bones that are more visible than usual
• A dull coat
• Dry skin
• Poor wound healing
• Susceptibility to infections

FAQ

Can I put my dog on a diet?

Yes, but for an underweight dog, the “diet” should be about adding calories gradually with a complete and balanced dog food, ideally after your vet has ruled out a medical cause. Increase portions in small steps (for example 10% at a time) to avoid stomach upset. Avoid fattening up your dog with table scraps, which can unbalance the diet, cause digestive upset, and some human foods are toxic to dogs.

How can I tell if my dog is the right weight?

The best way to tell if your dog is at a healthy weight is to use a body condition score (BCS) chart, which vets use for dogs of all breeds. At an ideal weight, you can easily feel your dog’s ribs under a thin layer of fat without seeing them stand out, and your dog has a visible waist when you look from above. If the ribs, spine and hip bones are clearly visible and you can’t feel any fat over them, your dog is underweight. Your vet can score your dog at the next check-up.

Why is it bad for a dog to be underweight?

Being underweight can lead to a number of health problems in dogs, such as:

• Muscle loss
• Poor wound healing
• Lethargy
• Increased susceptibility to infections
• Problems with pregnancy and birthing

Conclusion

There are many possible reasons why your dog may be losing weight despite eating. If you think your dog is underweight, the best thing to do is talk to your veterinarian. They will be able to help you determine the cause and recommend the best course of treatment.

In the meantime, there are a few things you can do to help your dog gain weight, such as feeding them more food and choosing a high-calorie food.