This article was updated on October 19th, 2022
Weight loss in older dogs can be slow and subtle, or it can be sudden and noticeable. Either way, if you have a dog who is losing weight it’s important to figure out why it’s happening.
This is because sudden weight loss could be a symptom of an underlying health problem – and sometimes this problem can be serious.
The earlier you find out what’s causing the pounds to drop off, the better your chances of getting the issue under control quickly, ensuring your senior friend’s quality of life is maintained in his twilight years.
You see your dog every day and are in the best position to notice any changes, even if they’re small or seem insignificant. It’s especially important to be on top of this when Fido is a senior.
In this article, we will discuss when old dogs typically lose weight and when you should be concerned about it. We will also review the top 8 causes of weight loss in older dogs and, finally, review what you should feed your old dog, with easy “tips & tricks” that can make a big difference.
Older Dogs Often Lose Weight As They Age
As many as 40% of seniors dogs (Source) actually gain weight as they enter their senior years (age 6-8 for larger dogs and 8-10 for smaller dogs). However, as time goes on and old age progresses to very old age, most dogs begin to lose weight and have difficulty maintaining their body condition. If your old dog is entering very old age, this could be the reason why your old dog is slowly losing weight.
This stage of life actually requires more calories and readily digestible protein sources to help your very elderly dog keep lean muscle (Jump to our section on: What Should You Feed An Older Dog That Is Losing Weight?). However, it is essential to keep in mind that weight loss could also be the sign of a more serious medical condition. This is why we recommend that your vet perform a full medical exam if weight loss appears to be a concern. Let’s discuss now when you should be concerned about an old dog losing weight.
When You Should Be Concerned about an Old Dog Losing Weight
So, what is considered to be ‘significant’ weight loss? What size drop is enough that it could be a sign of illness, or at least warrant a trip to your veterinarian?
Veterinary standards suggest that if your dog has lost 10% or more of his normal weight, then it’s something to be concerned about.
Not panicked, but concerned. Not all weight loss means trouble. It’s not unusual for even healthy senior dogs to lose weight slowly as they age. Things which can cause this type of weight loss include:
- Loss of muscle mass
- Reduced appetite
- Poor absorption/digestion of food
If the weight loss happened gradually, it’s less likely to be caused by a serious health problem. If the weight loss happened fast, and especially if you notice other symptoms, it becomes very important to visit your veterinarian as soon as possible. In any case, it’s obviously important to rule out an illness, even if the weight loss is slow or subtle.
However, once given a clean bill of health, there are some simple steps you can take to help keep weight on your older dog (as long as he/she isn’t overweight to begin with).
If your older dog has lost 10% or more of his body weight over the past few months (or within a year) then a trip to your veterinarian for a full check-up would be advisable.
You also need to visit the vet asap if your dog:
- stops eating completely
- vomits, dry heaves and/or has diarrhea
- is severely constipated or his belly is distended
- seems stressed or is panting/pacing/whining
- is lethargic, depressed or confused
- is acting differently
Top 8 Causes Of Weight Loss In Older Dogs
Most health problems result in more than one symptom: weight loss in older dogs can be a sign of several conditions, and it’s often the OTHER symptoms that will give your vet the right clues. If you notice that your senior dog is losing weight, pay close attention to his other bodily functions and behaviors and make a note of anything that seems out of the ordinary. Is there anything else that seems off with your old friend?
This will give your vet more ‘ammunition’ to use when making a diagnosis. Here are the top causes of weight loss in older dogs:
1. Dehydration:
If you notice weight loss and…
- Dry ‘rubbery’ gums
- Lethargy
- Sunken eyes
- Loss of skin elasticity
- Less urination
- Dark urine
Possible Cause:
- Dehydration
The aging process can cause overall loss of fluids and weight loss in older dogs. This is normal, but it means that you need to make sure that Fido gets plenty of fresh water every day.
What you can do: You can increase his fluid intake by adding broth (low sodium) to his kibble. Canned dog food (wet) contains much more water per cup than dry food does, so mixing some with the dry kibble can also help. Senior dogs whose senses of smell or taste are fading, who have dental issues, or who have become ‘picky’ eaters, can also often be encouraged to eat more this way too.
Diseases that affect older dogs can also cause dehydration, so have Fido checked out by your vet to make sure there’s no underlying health problem.
2. Dental problems
If you notice weight loss and…
- Excessive drooling
- Difficulty eating/chewing
- Bad breath
- Swollen or bleeding gums
Possible Cause:
- Dental problems
Weight loss in older dogs can sometimes be caused by something as simple as broken or decaying teeth, gingivitis, or gum disease. There are more serious oral conditions such as tumors too. Your vet needs to look inside your dog’s mouth as soon as possible.
3. Diabetes
If you notice weight loss and…
- Excessive thirst
- Excessive urination
- Increased appetite
- Lethargy
- Repeated urinary tract infections
Possible Cause:
- Diabetes
Diabetes can cause an older dog to lose weight because it stops his body from getting the energy it needs from glucose the way it normally would. So, his body tries to convert fat, or protein into energy instead. This doesn’t work very well at all, and Fido will soon use up any reserves he has, and no matter how much he eats his system can’t keep up and he’ll continue to lose weight. Learn more about diabetes in older dogs.
4. Cancer
If you notice weight loss and…
- Decreased appetite
- Sudden lethargy
- Unusual bleeding
- Lumps, bumps or swelling
- Distended abdomen
- Limping or lameness
- Unusual urination – frequency or amount
Possible Cause:
- Cancer
Cancer is one of those diseases that can be very difficult to diagnose through visible symptoms alone. There are many different types of cancer, and some of them have no obvious symptoms until they’ve become advanced and spread. BUT you know your senior dog better than anyone else, and you are in the best position to notice what might be very subtle changes that could be warning signs.
Please don’t panic and assume Fido has cancer if he fits one or two of the symptoms above, but have your veterinarian give him a thorough check-up and mention ANYTHING you think might be relevant.
5. Liver or gallbladder disease
If you notice weight loss and…
- Decreased appetite
- Lethargy
- Increased thirst
- Vomiting
- Diarrhea
- Fever
- Pain (panting/pacing/drooling)
- Pale or yellow gums
- Yellowing of skin/eyes
Possible Causes:
- Liver disease
- Gallbladder disease
The signs of liver disease in dogs can be very subtle, but sudden weight loss is one of them. The yellowing of gums or skin (jaundice) often indicates a liver or gallbladder problem. Several of these symptoms could point to other digestive problems, so again don’t panic and assume that Fido’s liver is at fault. Only your vet can make an accurate diagnosis.
6. Kidney disease
If you notice weight loss and…
- Increased thirst
- Excessive urination (may contain blood)
- Vomiting
- Loss of appetite
- Pale gums
- Depression or lethargy
Possible Cause:
- Kidney disease
As dogs get older, major organs stop working as efficiently as they used to. Kidney disease can come on so slowly that you don’t notice it until the kidneys start to fail. In fact, the kidneys are great at compensating until they are about 70% damaged, so often when signs appear, the disease has already progressed quite far.
This is another reason to be very careful about monitoring Fido’s overall health carefully and get help if you notice weight loss in older dogs, especially if it’s accompanied by any other signs of illness. Early diagnosis of any problem makes the prognosis better!
7. Heart disease
If you notice weight loss and…
- A chronic cough
- Tires easily
- Exercise intolerance
- Excessive panting
- Irregular heartbeat
- Restlessness
Possible Cause:
- Heart Disease
Heart problems in dogs can show subtle signs early on, and mistaking these for the normal ‘slowing down’ of old age isn’t unusual. But, as with most diseases, the earlier a diagnosis is made the better. Many heart conditions can be managed with a combination of medication and lifestyle changes – if they’re caught early on. Learn more.
8. Lower back issues or hip arthritis
If you notice weight loss and…
- Wobbling
- Lameness
- Scuffing the toes
- Incontinence
Possible Causes:
- Lower back issues, such as spondylosis
- Hip arthritis
Lower back and hip issues can lead to difficulty walking normally in the hind quarters which can lead to depletion of muscle mass. It’s a common sight for an elderly dog to look pretty chunky at the front end, but skinny in the hind quarters as the lower back and hips are the most common areas for age-related orthopedic issues to occur.
If you are aware that your dog has an elongated back or hip dysplasia, talk to your vets about lifestyle management to prevent them from developing into degenerative orthopedic conditions.
Summary: Below is an infographic summarizing these 8 common conditions causing weight loss in senior dogs, with a summary list of typical symptoms:
What Should You Feed An Older Dog That Is Losing Weight?
If no underlying medical conditions are found, and a healthy older dog loses weight, make sure that its diet is adequate. As discussed above, older dogs, especially very old dogs, need a calorically dense diet, so they do not have to consume as much to obtain their caloric needs. The protein source needs to be high-quality and easily digestible. If the dog has issues with deceased taste or smell, top-dressing the food or soaking it in an attractant may be helpful.
There are many diets on the market for senior dogs. Assuming your dog has no underlying health conditions that require special dietary needs, the most important factors to consider are protein, fat, and fiber:
- Protein
It was previously believed that protein should be restricted in senior diets because it may potentially damage the kidneys. Though this is true in dogs with kidney disease, it is not the case with animals with normally functioning kidneys.
Determining whether the kidneys are healthy and functioning well is vital, and screening blood work should be performed on all dogs at least annually. In healthy older dogs, their diet needs to contain increased protein, and a minimum of twenty-five percent of the calories should be from protein.
- Fat
Fat should be restricted in elderly dogs with health issues such as pancreatitis or any digestive sensitivities to fat. During the early stages of older age, a moderate fat content in the diet will be helpful to control weight gain in a dog with a slowing metabolism.
Then, as the dog becomes truly geriatric, adding high-quality fats to the diet will not only make the diet more attractive to a picky eater, but also increase the calorie content and improve protein efficiency.
- Fiber
Fiber, like fat, may have opposite roles in the early stages of old age as opposed to the later stages. In the beginning, adding fiber to the diet is a great way to satiate, or give a feeling of fullness, to a dog when they eat. A dog consuming more fiber will feel full and satisfied while also consuming fewer calories. Fiber may also be used to alleviate constipation issues.
Again, however, diets often need to be lower in fiber in our truly older dogs to allow for more caloric density in the food and make the diet more easily digestible.
Properly feeding an aging dog can extend their healthy and happy years dramatically. It is vital to rule out any medical conditions and consult with a veterinarian if any questions or concerns arise.
Read more with our 9 Tips to Get Your Old Dog To Eat More or our recommendations for Best Dog Food For Senior Dogs.
What To Do About Weight Loss In Old Dogs
A premium dog food that is a good fit for your golden oldie’s health and age, along with appropriate exercise, is often enough to keep dogs at an acceptable weight no matter how old they are.
Lots of dogs gain weight as they get older, and a gradual thickening of the ‘waistline’ is pretty normal. In an otherwise happy, healthy older dog this isn’t usually cause for concern.
But rapid weight gain in older dogs, just like rapid weight loss, is a different story, and needs to be evaluated by a veterinarian.
If your senior dog seems a little thinner, but it’s a change that has happened gradually, it’s less likely to be caused by a serious health problem… but it’s unusual enough to warrant a visit to the vet. However, if the weight loss is sudden (or slow but obvious), and especially if you notice any other signs that Fido isn’t feeling well or acting normally, then it’s very important to have him examined by your veterinarian asap.
Treating the weight loss itself can only be done by treating the problem which is causing it to happen, and the only person who can make an accurate diagnosis is your veterinarian.
There’s no need to panic or assume the worst, many times it’s something simple at the root of the problem, and even chronic or serious illnesses can be treated or managed.
All dogs should be seen for a thorough examination with a veterinarian at least annually, but senior dogs should be seen bi-annually. Dogs cannot talk and are therefore unable to tell anyone when there is something amiss. It is also essential to bear in mind that our canine companions age much faster than we do.
Weights should be tracked, and any changes without explanation may be cause for concern. If a weight loss is noticed, it is essential to provide a thorough history to your veterinarian. Changes to the dog’s life such as food changes, medications or supplements added or discontinued, stress or significant life events, injuries, and any new or abnormal behaviors should be documented. Based on the history provided and a physical exam, the veterinarian will perform necessary diagnostic tests.
So, get Fido that check up and you can get peace of mind!
Do Older Dogs Eat Less?
Studies have shown that older dogs require an average of 20% fewer calories to keep the same weight as their younger counterparts. Senior dogs who continue to eat the same quantities on the same diet may start gaining weight: as dogs enter more mature years, it is indeed common for them to add extra weight. Like in humans, changes to the metabolism cause the body to burn fewer calories and store more in the form of adipose (fat) tissue.
As a result, obesity is a frequent issue with older dogs: a nutrition study for aging dogs (link) mentioned that 40% of older dogs are overweight. Most dogs that are considered seniors will do well on a diet with less fat and fewer calories initially.
However, as time goes on and old age progresses to very old age, most dogs begin to lose weight and have difficulty maintaining their body condition. If your dog is entering very old age, this could be the reason for the weight loss.
This stage of life actually requires more calories and readily digestible protein sources to help the very elderly dog keep lean muscle. Complicating matters for these very old pups, decreased appetite, due to changes in taste and smell, can make eating a difficult task: physical issues such as arthritis can make picking up, chewing, and swallowing food difficult.
A consultation with a veterinarian is essential to address any medical conditions and identify a diet tailored to your senior dog’s specific needs.
It may be helpful to raise food bowls off the ground, add substances to improve the smell and taste of the food, and use foods that are calorically dense with easily digestible protein sources. Dogs with specific medical conditions may also require special diets. Read our 9 Tips to Get Your Old Dog To Eat More.
Related posts about senior dog nutrition:
Disclaimer: This website's content is not a substitute for veterinary care. Always consult with your veterinarian for healthcare decisions. Read More.
Thank you for your info!!
My 11 year old male boxer is losing weight rapidly. He is on prednisone and high fiber diet. The vet says he has ibs since his X-rays sonogram and blood work showed nothing more. I hope he’s right. The dog is lethargic, has the sunken eyes and overall just doesn’t look well.
How is you dog now, did you find out what was wrong.
Why a high fiber diet? Dogs are carnivores and prednisone is toxic. Up the protein and research proper grain free diet preferably homecooked with adequate minerals and digestive enzymes for dogs.
Could this be a thyroid problem?
My 13 year old Lab has just gone blind. She is very disoriented. She will only eat small amounts. She also has a large tumor over her eye but the vet says doesn’t seem to be in pain. She has never been affectionate which has never been like any of my dogs. She is also drooling alot. I don’t know what to do. I don’t know if she is just adjusting to blindness or what.
Hello Emly: I was touched by your post and wondering if you found out anything about your lab’s situation? We have used Internal Medicine Vet Specialists in the past when the GP’s are stumped. Also the internet may have some things that you can find as points of discussion to run past a good Vet. I’m wondering if one of the Vet schools has a clinic or a consultation service they offer over the phone that could give a second opinion? I know Cornell has had this service to help us with our cats int he past, not sure about dogs. Maybe she is drooling because she can’t see and I would imagine is a bit disoriented, I know I would be. Sure thinking about you and your baby!
Emily: did you find out what is going on with our lab? We have a lab about the same age, she has not gone blind but sh his losing rapid weight but otherwise seems fine so we are going through the trial things of looking at everything. Do you know if a good Internal medicine vet can help your Lab determine what is going on. Sometimes I ask the “what if” questions from vets or even for my own health if they want me to do all sorts of tests but tests if necessary can rule things out. That’s where a good Specialist vs. a GP could help. Also are their vet schools which can give you a second opinion over the phone? I know Cornell has had consult service for a nominal fee for our cats in the past, wondering if there is a thing for dogs? Sure thinking about you through this.
My dog is a terrier mix and is going on 14 years old. She lost the use of her hind legs when she was around 8 yrs untill I started putting her in a pool and made her swim and before you know it she was walking again. Now she’s starting to do it again and shes getting real skinny rapidly it seems to the point where her ribs stick out and I don’t know what to do. She also drinks alot of water and urinates alot uncontrollably
oh, that does not sound good that she is drinking a lot, peeing uncontrollably and losing weight. Could be thyroid or renal failure. I would definitely get her to a vet ASAP
Excessive thirst and frequent urination are symptoms of diabetes, as is weight loss. This goes for humans too. when the blood sugar is very high, it causes weight loss, and the excessive thirst and frequent urination is the way to try and dilute and flush the extra glucose from the system. I would definitely get the blood sugar checked.
Tom, did you end up at the vet? Any insight? I have a 13yo Jack Russell Terrior that is doing the exact same thing. His back legs give a lot, he hates being upright, and loss of urine control. I try to chalk it up to old age, but I think we are due for a vet visit.
I am baffled that my 10 yr old Golden now weighs 68 lbs and you can see his ribs. past year.
He had a malignant mast cell tumor removed from his ear in January and an ultra sound after that plus a follow up one in June which showed that all his organs were normal. Then he had a small benign growth removed from another part of the same ear in November but again no indication of cancer in his organs nor signs in the full blood work done.
He has the same appetite, there are no changes to his environment, and he is happy because he sees me a lot more since I retired in March. He’ll still snuggles and wrestles the way he always has (I rescued him at 15 mos). On the recommendation of my vet I have been almost doubling his food, he eats it all, and he still scrounges for other food after he eats, so there is no change in that. He tires more easily in the hot sun, and will only chase a ball for 10 minutes now instead of hours due to his age.
Any suggestions?
Male Border Collie/Husky mix,age12,in Fall 2017 his wt. went from 66#s to 51#s. Blood work normal,x-ray from his neck to tail showed all normal. No masses found externally either. Fall 2018 wt. dropped to 41#s. Developed pinched nerve in low back, started some knuckling on back paws & losing some use of back legs. One Vet treated him w/prednisone,muscle relaxer, & gabapentin. Dog finally able rest/sleep.Then he developed Vestibular disease & 1 wk later wt. dropped to 35#s. 2 Vets want to euthanize him, 2 Vets say continue back therapy meds added laser treatments. & chirop. adjustmts. Said back ailmts take time to heal as well as Vestibular & for me not to lose hope & I wanted to give my dog as much time as he needed. As still blood work & xrays all normal.
Hello checking in to see if anyone replied re:my poor dogs conditions. This all happening within a 2wk period. Where prior to onset of multiple ills., he is was eating & drinking normally,standing on all fours & walking well, w/normal urinating & bms. Thening 1st ailmt. pinched nerve in low back/hips & loss of use of back legs/knuckling. First wt.taken at this time he was 41lbs. One vet treating his pinched nerve, out him on new food to start wt.gain. pain in low back was out if control until 7th day of onset started gabapentin & mg boy finally got some pain relief & rest. 12th day new ills of vestibular disease. Wt. dropped to 34lbs. Has eaten a good meal everyday on 13th day he’s not taking water well,I’m fearing dehydration w/vestibular & he’s whimpering cries & barks seems to be in kind of daze…took him to vet, at vet she hasn’t started IV fluids which I asked for when walking into hosp. Told her of his pinched nerve meds & therapy, now of vestibular onset & my fear of now dehydration…she just wants to put him down. Shes focusing on his wt. at 34lbs now
Which I know he lost due to uncontrolled low back pain w/pinched nerve & loss of use of back legs in wk1.This vet is new to us but went here as only place for CTscan & to treat the vestibular & wt.loss. I’m in
grief strickin fog. My research says even sr. dogs w/time can pull out of pinched nerve & vestibular disease…but not dehydration…have I lost my wonderful boy with vet visit for her not jumping & giving him IV fluids ??? & her calling him a loss ??? With his wt. loss along w/pinched nerve & vestibular disease. Crying buckets shes taking him away OR is this best call for him now ? Recovery from all that has happened in 2wks too much for my sweet dog ?
Any comments, suggestions, anything greatly appreaciated
I have a 18-year-old terrier mix who has lost weight. He is still eating drinking and very active. He seems to be happy however when I bath him I can feel his bones. Should I be concerned. What can I feed him to fatten him up? He eats Science Diet for senior dogs.
I have a 14 yr old almost 15 yr old American Pitbull. Hes lost alot of weight and we have done everything we can to get the weight back on him with no luck. Hes lost use of his back 2 two legs and hes got blood in his urine and his stool. I’m worried about him can anyone tell me what the possibilities are that’s causing this?
I have a almost 15 year old ShihTzu. She is now blind but gets around very well, almost, she sometimes runs into things. Her appetite is good and she drinks her water. She has lost weight where you can see her ribs and hip bones. She has started begging for my food when I
Eat. She seems ok other than her loosing the weight. I haven’t taken her to the vet because everything is fine as far as her eating and drinking. Should I add wet food to her dry?
Hi, I have a 10 year old English Bull Mastiff. I am concerned with because he has been loosing weight. He’s overall pretty active when outside. While inside he does sleep a lot more. Appetite still seems good. I started him 2 months ago on a wheat free higher protein diet. His drinking seems ok. He done a head bobble, which lasted about 30 seconds but hasn’t happened again. I haven’t taken him to see the veterinarian yet. Should I
be concerned? Is there something different I should feed him to help him gain weight?
Hi, I have 17 year 5 mos old lab mix named Toby who has lost muscle mass over last 2 years. He has an overgrowth of gums and can’t completely close his mouth so drinks a lot of water. He’s a picky eater and always has been. Vision and hearing are not great but still loves his walks and would keep going until he collapses. He has quite a bit of arthritis. He gets blue mountain seniordog food, glucosamine, liquid multivitamin, powdered probiotics w digestive enzymes.. he also gets Cbd oil and omega flax oil. He is not incontinent but I trained him this year to use pee pads bc I work and he drinks and pees all day log. I add cornflakes and chicken or turkey of beef to his meal and he gets a lot o treats. If he were diabetic- should there be a way to treat him by not giving him needles. Any thoughts or suggestions ??
IMG_0889.jpgIMG_0889.jpg
My boy!!
Wow, what a kind vet. This lady writes articles online to help pet owners and takes the time to directly respond to comments…..all after working a 12+ hour day. Thank you for all that you do, Dr. Winnie 🦜🦆🐔 🦉🐓🐦
Avian Lover in California
My 11 year old male Newfoundland has lost 10 lbs in the past 4 months. He seems to have an increased appetite and is drinking more water. He is asking to go out more frequently, and recently I saw him dribble some urine after going out one time. He has become emboldened in taking food off peoples plates, right in front of them – something he’s never done. Tonight, he threw up his entire dinner moments after eating. But he then tried to eat the vomit, so it has not made him less hungry. He had a complete senior panel 4 months ago, and again last week. Both bloodwork and urinalysis revealed nothing. Vet is recommending an abdominal ultrasound, which we will do. But in my research, I cannot find anything that includes these symptoms along with increased appetite. Any thoughts?
Hi Rebekah,
I am sorry to hear that. The first thing that comes to mind is diabetes, which does cause those symptoms. But I would have thought it would show up on any blood panel your vet would run. Another disease that causes these symptoms is cushing’ss disease, but again, usually with changes on a normal bloodwork panel. Some cancers and gut problems can cause similar symptoms, and remember, it could be more than one thing. It sounds like your vet has a good plan, so fingers crossed it shows something! (Please note that the information here can only be used for informational purposes only and we recommend you continue to work with your vet to perform a full medical exam).
I have 2 senoir deer head Chihuahuas. Boogie and breezy. Boogie has lost weight fast, increased drinking water, won’t eat,he seems to be getting weaker everyday. I can’t afford to take him to the vet let alone the cost of tests. I love him so much and I don’t know what to do.