Is It Normal For A Senior Dog To Get Skinny? 6 Reasons and What To Do

It can be hair-raising seeing your dog drop weight, especially at an older age, which is when we all start to be extra observant of our dogs’ health. 

Most of the time, there is no cause other than old age. There can be many distinct reasons other than just climbing into their golden years, though.

If you’ve noticed your dog losing weight recently, we’re here to help you figure out why. Today, we’re covering five reasons why your senior dog may be losing weight and what to do about it. 

Remember, if this has happened rapidly, it’s best to take a visit to the vet first. While it may very well be treatable, a huge loss in weight over just weeks is a cause for concern.

In most cases, weight loss can be treated by changing diet, simple exercises, or treating a deficiency, among other minor fixes. 


Why Senior Dogs Lose Weight

They’re Just Getting Older

Senior dogs most often are either very active or do not eat as much as they should. If this sounds like your dog, then this is probably why it’s losing weight. 

Exercise is good, but when a dog is active and does not eat enough, weight loss follows. Many older dogs are very passive, and this often leaks into their diet. 

When dogs are lazy, eating food can be a chore. If your dog acts a little groggy, then it may be time to visit the vet to get suggestions on what should be done. 

Just remember that it’s ultimately common for a senior dog to lose a little weight; just make sure it’s not rapid and does not fall below the underweight category

Eating The Wrong Food

If your dog is contrarily healthy and is acting fine, perhaps give him a little extra food each day. 

You may also consider giving him healthy high-calorie treats to supplement weight gain. In some cases, the dog food you’re feeding may also be the reason. 

Senior dogs should only eat senior food, which has more ingredients explicitly added for senior dogs. If they’re not getting these ingredients, weight loss can be a result.

 Just make sure to switch your dog to the new food over ten days to avoid stomach upset. Over the years, I’ve changed my dog’s food as well. 

Simply adding a quarter teaspoon of bacon grease to the kibble worked to get my dog used to eat the new food. 

Lack of Appetite

A lack of appetite may also be the reason why your dog is losing weight. There are several reasons why this can happen. 

For starters, parasites, such as worms, can cause an odd feeling in the stomach, leading to a lack of appetite. 

There may also be other reasons such as diabetes, cancer, or kidney disease, but don’t automatically assume this, as it’s improbable. 

In some instances, dogs can suffer from depression, which can be treated most by exercise, a change in environment, or extra playtime. 

Your dog may love being rewarded, so offer a few treats after each meal. Eventually, your dog will come to expect treats after eating, which could motivate it to chow down more often.

Not Enough Sleep

When dogs do not get enough sleep, they’re prone not to eat well enough. In fact, it’s normal for senior dogs to sleep at an average of 16 or up to 20 hours each day. 

So if your senior dog is sleeping any less than that, especially at a rate of 8 hours per day, then a lack of sleep could be the reason your dog is skinny. 

You’ll need to make sure you know why your senior dog is not sleeping as much as it should. 

A few reasons could be that its environment isn’t ideal, such as a noisy living room, in an office, or if there isn’t much quiet time in your home. 

If there are noises that occur around your home that wake your dog, this can also be why, as breaking up sleep patterns can cause sleep deprivation, and consequently, lack of appetite.

The Not So Fun Reasons

In some cases, heart disease, cancer, kidney disease, or anemia can cause weight loss. 

In many cases, these illnesses can be fought and conquered, so never lose hope; you’d be surprised at how many fur babies become warriors after beating these illnesses. 

If you’ve tried everything and still fail to make your dog gain weight, it could be something serious, which is when you should visit a vet. 

The vet may be able to treat one of these illnesses rapidly, depending on the severity. 

The faster your dog gets to the vet, the better the chances of everything going well.

What To Do About It

Change Dog Food

Weight loss is a good reason to change your dogs’ food. Senior dogs should only eat senior dog food if you’re sticking with a dry food diet, for starters. 

Senior dog food, as mentioned before, has nutrients that senior dogs are often deficient in. 

It also has more fiber, which helps digestion, and ultimately, absorption of the food, leading to weight gain. Moreover, your dog may be intolerant of the food you’re currently feeding it. 

If you change dog food, slowly add 10% new dog food and remove 10% old dog food per day for ten days.

Consider Supplements

As with humans, dogs can have deficiencies, too, even if they’re eating as they should. To combat this, consider adding in a supplement or two. 

For example, if your dog is deficient in iron, this can cause anemia. Supplements such as iron can help get your dog back on track. 

You may also find that adding a general supplemental vitamin may help, too. 

However, it’s best to check with your vet first because supplementing something that your dog is not deficient in can lead to trouble, making the situation worse. 

Visit A Vet

Finally, if all else fails, your best bet is to visit your vet. 

If you’re feeding your dog raw meats, it may be too lean. Despite this, it’s best to visit your vet to rule out anything serious. 

A vet can run a blood test, check the bowels, and run tests on its feces to ensure everything is working right. In most cases, the treatment is simple if it’s even needed. 

The most likely scenario is manageable, but it’s always good to play it safe and go to the vet.


It can be stressful when determining if your dog is okay once it’s lost weight and begins appearing skinny. 

At such an old age, just about anything out of the ordinary can make us anxious when it comes to elderly dogs. 

Luckily, it’s simply old age, a need for new dog food, or a deficiency in most cases. It’s essential to look at the timeline of weight loss. 

If this has happened over several months, it’s likely a minor issue, if any at all. 

However, if your dog has lost weight over weeks, then it may be something serious. Whatever the case, try the steps above, and when in doubt, visit a vet.

Written by Brian Rucker

Brian Rucker has been a dog lover since childhood. He has had his Lab Mix with Hound for over 10+ years now! They enjoy playing outdoors together. Brian loves sharing his knowledge about all things dog on this website. Read more of Brian's articles.