How to Fatten Up A Dog: 5 Tips for Weight Gain

All owners want their dogs to be at a healthy weight, but not all dogs are “good eaters.”

If you’ve got an underweight dog, it can be stressful to get her to gain weight. People can be quite quick to judge, even if you are doing your best to get your dog’s weight back up.

Call your vet if you’re really struggling to get your dog to gain weight. Dogs that continue losing weight despite eating food, or experience a sudden change of appetite, need to see a medical professional quickly.

Read on to learn five ways to fatten up a skinny dog!

How to Fatten Up a Dog: Key Takeaways

• It’s important that your dog’s body weight remains in the healthy zone. While some dogs may be slightly heavier or lighter than other members of their breed, you can consult a body condition chart to ensure your pup is in the correct weight range.
• There are several reasons your dog may have trouble maintaining a healthy body weight. This includes things like general pickiness, stress, and illness.
• Be sure to consult your vet if your dog is underweight. Your vet can not only help ensure your dog isn’t battling an illness, he or she can help guide your efforts to pack some pounds on your pooch.

Reasons a Dog May Have Trouble Maintaining a Healthy Body Weight

There are a variety of reasons why owners might want to learn how to fatten up a dog, and why a pooch may have trouble putting on weight, including:

Picky Eaters. Some dogs are just plain picky about what they eat — these dogs want the good stuff and are willing to hold out for it!

Sick or in Pain. Illness, pain, and/or stomach issues can also cause dogs to eat less than their owners would like. If your dog skips a meal or two because of a stomach bug, you might not need to panic. But if your dog is chronically turning up food, then it might be time to visit the vet.

If your dog is normally a voracious eater and suddenly isn’t interested in food, get in to the vet as soon as you can.

In the nearly two years I’ve owned my dog Barley, he’s only turned up his nose at his breakfast once. I took him to the vet, and it turned out he had a raging infection from a small cut on his leg. If I’d ignored it and gone to work, things might have taken a turn for the worse.

Stressed. When dogs are stressed or depressed, they may pass up on food. People can be the same way! If your dog won’t eat after a stressful event or doesn’t eat when she’s alone, this might be the culprit.

Whatever the cause of your dog’s dinner distress, we want to help our underweight dogs get to a healthy weight.

How Do I Know If My Dog Is a Healthy Weight?

When trying to determine a healthy weight for your dog, your veterinarian’s office is always a good place to start. Different breeds may have a naturally slimmer or stockier look, and your vet can help make sure you create appropriate weight goals for your canine.

Don’t forget that “normal” might not be healthy for many breeds. It’s not uncommon to see pugs, Labs, and Chihuahuas that look like small hippos — but that doesn’t mean it’s healthy.

This reminder goes both ways: a healthy greyhound will be quite boney! It’s not unusual to see several ribs and even hip bones on a healthy greyhound, while a similar level of bonyness in most other breeds would be concerning.

In general, you should be able to see a narrowing around your dog’s waist. Most dog breeds should also have faint ribcage outlines visible.

Finally, you might see some differences in your dog’s weight based off of activity level. When my border collie is at “competition weight” for agility, herding, and canicross, he’s very lean and muscular. I let him gain a bit of weight early in the winter when he’s in his “off season.” He stays fit and healthy, but he doesn’t have to be ultra-trim year-round!

This simple graphic from Purina can help you decide if your dog is over- or underweight. 

I just helped my foster dog, Naomi, gain some serious weight. When she first came into my home, you could see seven ribs and her hip bones poked above her back!

She had no muscle tone, tired easily, and worst of all, would not touch her kibble for breakfast or dinner. After at least three days of trying to coax her to eat, I was at my wit’s end. I felt like a failure of a foster parent, and was legitimately worried that Naomi might waste away.

Was I being played by a foodie dog? Not in this case! Naomi’s reluctance to eat was probably based in some pretty serious stress about her recent life changes paired with an upset stomach from switching foods.

How to Fatten Up A Dog: 5 Tips for Getting Weight On

A combination of these solutions ended up being what got Naomi to a healthy weight in just a few weeks!

For Naomi, the biggest problem was stress. Before I brought her home as a foster, she’d had quite the month.

Her owner left Florida, drove to Colorado, lived in his car with her for a few weeks, then left her at the shelter when it all got to be too much.

Naomi spent a few days at the shelter before being marked for behavioral euthanasia due to her aggression towards other dogs. I stepped in and took her. With that level of upheaval, is it any wonder she wasn’t interested in food?

1. She’ll Eat When She’s Hungry

This is what I kept hearing, and it’s true – your dog will eat when she’s truly hungry.

If your dog skips a meal or two or is having a hard time adjusting to a new situation, she might start eating when things settle down.

Just keep offering food in different forms. She’ll eat when she’s ready — and this might take a while! Be patient and keep trying!

While this is true, that doesn’t mean just wait it out. Try to address your dog’s underlying concerns, such as physical health or stress level. This will often help bring your pup’s appetite back more quickly.

2. She’ll Eat When She’s Healthier

If your dog has a change in eating habits that persists beyond a few days, see a vet. If the change is particularly sudden or extreme (like with my dog Barley), don’t wait. Just go in to see the vet and get a professional opinion.

Loss of appetite and weight loss are both potential signs of serious medical conditions.

Take your dog to the vet to rule out any underlying health conditions that may be causing her lack of eating.

In Naomi’s case, her loss of appetite was paired with diarrhea and vomiting. That’s a major red flag! Naomi’s eating issues turned out to be stress-related (see below), but we still took her to the vet to be sure.

The vet prescribed some probiotics and suggested a few foods that would be easy on Naomi’s stomach once she started eating again.

3. She’ll Eat If The Food Is Yummier

As a dog sitter, I frequently care for dogs that seem uninterested in their food. Some dogs just don’t eat well when their owners leave — they miss them! However, dogs will have a hard time turning their noses up at truly drool-worthy dinners.

If your dog won’t eat when she’s left alone, it could be related to separation anxiety. While skipping a meal or two probably won’t hurt your dog, it’s unwise to leave this separation anxiety untreated. Get help from a separation anxiety specialist to make your dog feel better.

Try making dog’s dinner better by drizzling tuna, olive oil, or egg over the kibble. Just be sure not to create a picky eater by spoiling your dog too much!

Other times, condiments won’t cut it and you’ll have to change the entire entree with a new brand of dog food. Some dogs will only be interested in eating higher quality dog food — and why not?

They probably deserve it! Be careful, though — the most expensive food could still be gross to your dog!

Something as simple as adding tuna or switching to a new brand of food can work wonders when it comes to fattening up a skin-and-bones dog.

If your dog is really struggling to pack on the pounds, don’t worry about creating a picky eater. Just feed her what she’ll eat to get her healthy. You can always wean her off of the ultra-tasty food later.

With Naomi, we tried about five different types of food with different protein sources. Nothing was working, except for treats. She wouldn’t eat her food but would take treats gladly.

Eventually I realized that the problem wasn’t the taste — it was that the treats were hand-delivered.

4. She’ll Eat When She’s Less Stressed

Some dogs will refuse to eat when they’re stressed out. Don’t think of this as being disobedient or wilful. Rather, think of this as your dog’s way of letting you know that she’s really struggling to deal with life right now.

Some of my formerly picky dog-sitting clients eat dinner now that they know me and feel safe with me when their owner is gone. It just took a bit of getting used to me. Many dogs with separation anxiety won’t eat when they’re alone. Some dogs will skip meals after the Fourth of July from fear of fireworks. New shelter and rescue dogs often skip meals due to the big changes in their lives.

In the case of Naomi’s eating issues, stress was the root problem. Naomi had just experienced a massive upheaval prior to us taking her home from the animal rescue – she was confused and scared. As she settled into our home, her appetite returned. This took nearly two weeks!

While refusing food due to situational stress is fairly normal in dogs, if your dog frequently stops eating due to stress, take her to a vet. She might be anxious due to a medical issue or something awry in her environment.

There are lots of ways to help reduce stress for your dog. The first step should be to remove whatever is stressing your dog out, if possible. This might mean skipping town during the annual fireworks display, or putting on a white noise generator during thunderstorms. You can leave dogs with separation anxiety with a sitter.

In short, you have to remove the source of stress as the first step.

Depending on what specifically stresses your dog out, that might be all you need to do. Otherwise, work with a trainer to create a plan for reducing stress in your dog’s life. Products like Adaptil diffusers, Thundershirts, and anti-anxiety medications can also help. For a more detailed example, check out our article on working with dogs that don’t like fireworks.

5. She’ll Eat When You Help Her

Some nervous dogs need extra encouragement at mealtime! When I eventually noticed that the only food Naomi ate was the food I handed to her, I decided to try hand-feeding her dinner.

After four days of not eating and a lot of desperate phone calls with the rescue and vet, we got Naomi to eat a meal.

I took a handful of kibble and offered it to her. I praised her just for showing interest. She took a tentative mouthful, and I praised her more. She spat most of it out, but I was onto something!

We kept trying this throughout the night. Eventually I coaxed her into eating a full cup of food simply by giving her lots of verbal praise for showing interest in food. I literally just told her she was a good dog when she ate. This may sound bogus, but it ended up being the game changer for Naomi!

Go ahead and give this a try with your picky pooch. You might find that just being supportive of your dog is more helpful than drizzling bacon grease all over the kibble!

It might sound crazy, but playing games with your pup’s food is another way to get her interested in eating! Treat-based training and puzzle toys can sometimes help pique a picky pup’s interest in food. This phenomenon is known as contrafreeloading, where animals actually prefer to work for their food. Give it a shot, it can’t hurt!

Bulk Up Dog Bonus Tip: Try High-Calorie Treats and Food

Some dogs won’t eat meals, you may be able to entice them to eat with special, high-value treats. This is a good way to get calories in while you’re working on figuring out how to get your dog to eat a full meal.

We gave Naomi lots of hot dog, cheese, and stuffed Kongs to get her some calories and put some fat on her. I highly recommend trying to get some (heck, really any) food into an underweight dog while you address the long-term problem.

We did not end up spoiling Naomi into a picky eater who would only eat bratwurst and gruyere, since her problem was anxiety based and not due to pickiness.

There are also specific high-caloric dog foods designed to help skinny dogs gain weight — experimenting with those specialty dog foods can help your pooch bulk up fast.

Best Dog Foods to Help Dogs Gain Weight

Once your dog is eating again, getting the right food into her bowl (or better yet, puzzle toy) will help make weight gain smooth and easy.

Talk to your vet during this process. If your dog has been chronically malnourished or has a sensitive stomach, your vet might want you to skip the bulky foods in favor of an alternative that’s easier on the stomach.

We have a whole article on different foods that help your dog gain weight, but here are a few highlights here:

• Bully Max High-Performance Food: This high-protein, high-fat food has premium ingredients and a premium price tag. It’s marketed for bully breeds but is fine for any dog breed.
• Elite K9 Maximum Bully All Stages Dog Food: This brand also markets heavily towards bully breeds, but Elite K9 will help any dog gain muscle and weight. This brand also provides oatmeal and pumpkin in its food, helping soothe digestive systems.
• Nature’s Logic Canine Meal Feast: This meat-based food also comes with a variety of probiotics and enzymes to help keep your pup’s stomach calm while she gains weight. It comes in a variety of flavors and protein sources, making it a good choice for dogs with allergies.
• Blue Buffalo Life Protection Adult Food: This food is formulated with Glucosamine and Omega 3 and 6 acids to help protect your dog’s skin, coat, and joints. It contains far more brown rice than other foods on this list, but is a great choice for dogs with skin or joint issues.

If your dog really needs to gain weight, help her do it!

If your dog is eating food but not gaining weight, it’s time to see a vet. Increased or steady appetite paired with weight loss can be a sign of serious health conditions.

Have you ever had an underweight dog? How did you get your dog up to an appropriate weight? Share your tips in the comments!