Why is my senior dog losing weight?

There's probably one of two questions in your mind as you're reading this article. You could be worried that your dog is losing weight despite having a healthy appetite. Or, you are actively trying to reduce your dog's body weight. Both of these trains of thought are important to educate yourself on to reach your pets health and weight goals. 

So, is it normal for senior dogs to lose weight? The answer is a frustrating yes and no. 
Some weight loss as a dog ages is normal and to be expected, especially when the composition of a senior dog's body changes with age. If the weight loss is rapid  yet combined with a normal appetite, this is a cause for concern. 

Is it normal for senior dogs to lose weight?

No it is not normal for your senior dog to lose a significant amount of weight. Some gradual weight loss can be normal as your dog ages, relating to loss of muscle mass (sarcopenia). Senior dogs are less active, and as such their bodies respond by reducing the amount of muscle they carry, as it's a high energy fibre type to maintain and replace. 

Significant or rapid weight loss needs investigation. As a general rule if your dog has lost more than 10% of their normal body weight you should contact your veterinarian. 

Knowing your dog's normal weight can be really helpful in distinguishing a gradual decline from a true medical issue. If you have weight scales at home, a monthly weight check can allow you to track trends in weight loss or gain. If you do not have a weight scale, try using Body Condition Scoring to get an idea if your dog is moving up or down the 1-9 scale. A healthy dog is a 4-5 on the BCS scale. You can clearly see the waist and feel the ribs on a healthy dog without seeing them. If you are not sure, a vet can help talk you through how to condition score for the first few times.

Why is my senior dog losing weight but still eating? 

Weight loss can be caused by medical concerns, behavioural issues or dietary considerations. What raises the alarm for a medical condition is a senior dog losing weight but still eating. A good appetite should enable a dog to keep their weight consistent (or increased). Weight loss may be the only symptom you notice, but it's an important symptom to notice and take action on. 

Common medical issues in senior dogs losing weight but still eating I diagnose as a veterinarian are: 

Dental disease 

A very common cause of weight loss in senior dogs. Dental disease is painful, but dogs rarely show signs of dental disease until the condition is advanced. To cope with the pain a dog may try to eat on the unaffected side of the mouth, or swallow food without chewing properly. A veterinary exam will detect dental disease, and the treatment is usually curative, allowing your dog to regain the weight they may have lost. Read our guide to spotting the signs of periodontal disease in dogs.

Malabsorption

The term malabsorption describes a digestive tract issue whereby the intestines cannot absorb nutrients adequately, leading to weight loss even with a good appetite. Some examples of malabsorption diseases are EPI (exocrine pancreatic insufficiency) CIE (chronic intestinal enteropathy) and IBD (inflammatory bowel disorder). 

Diabetes Mellitus

Dogs with diabetes are not able to absorb glucose, and so the body adapts by breaking down fat and muscle tissue instead. This leads to weight loss, whilst appetite remains unchanged. Other signs of diabetes include increased thirst, urination and a cloudy appearance to the eyes. Learn more about spotting the signs of diabetes in dogs and how to help.

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Cancer 

Cancer of any kind will lead to weight loss. Sometimes the only symptom we see of an internal mass or cancer is weight loss. The weight loss is related to the chemical messages released by the cancer cells, leading to breakdown of muscle and fat in the body. This is why it's really important to know what your dog's normal weight is, and to weigh at least three or four times a year to spot subtle signs of weight loss early on. Do you know the warning signs of cancer in dogs? 

Kidney Disease

Kidney disease affects roughly 10% of the senior dog population. Signs of kidney disease are increased thirst and urination, weight loss. In later stages of kidney disease, appetite loss occurs. 

Intestinal parasites 

If your dog is hosting a worm burden in their intestines, this will result in weight loss. The parasites interfere with the normal digestive process, and reduce the intestinal ability to absorb valuable nutrients from their food. Other symptoms of intestinal parasites in senior dogs are loose stools or diarrhoea, blood in the stools and a swollen belly. Thankfully parasites are treated very easily with prescription strength anti-parasiticide medication.

Heart disease 

Heart disease affects blood flow to organs such as the intestines. The reduced or slower blood flow to the intestines causes reduced uptake of nutrients from the digestive tract leading to weight loss. Other signs of heart disease include coughing, increased breathing rate and collapse or fainting episodes.

If your senior dog is losing weight despite eating normally, book a vet appointment as soon as possible. Do not wait to see if it resolves on its own- unexplained weight loss is one of the most important warning signs in an older dog. 

Muscle loss vs fat loss — Why it matters in senior dogs 

When dogs lose muscle, it can be a normal age related muscle wastage. This is usually due to reduced activity levels, and changes in diet. Muscle wastage can speed up if there are underlying health problems. If you notice rapid loss of muscle then this is worth getting checked out by a vet. Signs of muscle wastage include being able to see bony prominences such as a line on the top of the head, and the hip bones or spine. 

Fat loss is usually more concerning, as it is linked to medical causes for weight loss such as diabetes, but can be related to feeding a calorie restricted diet. If you are trying to get your dog to lose weight, fat loss is the most beneficial for senior dog health. 

Loss of muscle is important even though it may not be a medical concern. It affects a dog's ability to move, play and even affects balance. If you notice small changes in muscle mass, it can be corrected through gentle exercise and simple physiotherapy exercises.

How to help a senior dog gain weight 

If you want to help a senior dog to gain weight, it's important to rule out a medical reason for weight loss first. No amount of increased feeding will fix a medical reason for weight loss, so save yourself the stress and ask a vet for a check up first before starting dietary changes. 

If your vet check was normal, you can then look at altering your dogs diet to increase their weight. So, to help your senior dog gain weight you could try the following tips. 

Age specific diets 

Senior diets (sometimes called mature, or 7+) are specifically formulated to support dogs in their golden years. They have reduced calories to match their energy needs, as fat gain can cause its own health issues.

To support muscle maintenance and growth, the protein levels tend to be of high quality, digestible protein. This is beneficial as the body does not have to work as hard to absorb and break down the protein into usable molecules.

Age specific diets will have extra omega oils- helpful to have the balance of ‘good fats’ and their anti-inflammatory properties. 

Meal toppers 

Meal toppers are a great way to increase enthusiasm for mealtime, they add variety and texture to the daily meal. It's also a sneaky way to get extra fats and proteins into your dog's diet. Try scrambled eggs or some chopped chicken. By using meal toppers we increase the density of the nutrition without particularly increasing the volume, which can lead to digestive upset or constipation. 

Little and often 

Feeding smaller meals more frequently can increase the absorption of the diet in your senior dog. Instead of 1-2 meals, try to increase to 3-4 smaller meals. This keeps the intestines busy and increases the absorption of nutrients and vitamins from the food. 

Exercise 

Gentle exercise such as lead walks, physiotherapy, hydrotherapy and acupuncture can help maintain and slowly build back lost muscle. It's a slow process, but very rewarding when you see the results. Senior dogs with muscle loss can have conditions such as arthritis which can cause discomfort. Using medications, supplements and small home changes can increase their comfort level and ability to exercise to maintain muscle tone. 

Best ways to help an overweight senior dog lose weight safely

The best way to help a senior dog lose weight is to work with your vet to create a weight loss plan. Your vet can work out a sensible weight loss plan, reducing calories too quickly can lead to unwanted side effects such as pica (eating non food items). Take a look at our blog on how to identify if your dog is overweight.

You should measure the food out each meal, using weight scales to check. We are all guilty of estimating roughly what our dogs' meals should look like, measuring takes out the guesswork and allows the diet to be effective. 

Weighing your senior dog at home or the vet clinic three to four times a year lets you track your dog's weight. As we see our dogs daily, we can mentally adjust to their new body shape, and not notice weight gain or loss until it is advanced. The scales do not lie, and give us evidence for weight loss or gain in real time. 

If you use training treats or meal toppers, you will need to let your vet know to add into the calorie calculations. Cutting out treats, or using low calorie treat alternatives like carrot can help reduce calorie intake significantly. 

It can be tempting when dieting to jump into intense exercise. Your senior dog may not be able to cope with intense exercise without building up to this first. Start with low impact exercise such as lead walks or swimming. These types of exercise are kinder on senior joints, who usually have some degree of arthritis present. Read more on exercising older dogs.

When your dog can comfortably manage slow paced exercise, consider weighted jackets or increasing the intensity slowly to help burn more calories. 

Check in regularly with the vet clinic, around every 4 weeks for a weigh in and body condition score. Your dog's diet can be readjusted to meet their new weight loss targets. Having a support system around you will improve your dog's weight loss outcomes, and allow them to live a longer, happier life. 

Even losing 1-2% of body weight per week can make a meaningful difference to a senior dog's joint health, mobility and quality of life- slow and steady is the right approach.

When to take your senior dog to the vet about weight changes 

Urgent vet care is needed if your dog is rapidly losing weight, or showing other signs such as increased thirst and urination alongside their weight loss. Weight loss in the region of 5-10% is not normal, and should be investigated urgently. 

If your dog has gradual weight loss, or loss of muscle mass, this should be a discussion point with your vet at your dog's next routine check up. The same is true if your dog is struggling to maintain their usual weight on their regular diet, but not losing too much weight. There may be an easy solution such as treating dental disease. 

Summary

Managing a senior dog’s weight is a fine balance, and is a source of worry for most senior dog owners. Take comfort in the knowledge you have discovered today, and know that as an individual researching how best to help your dog, they are in good hands. Take the tips you have read here, and reach out to your vet to investigate a medical reason for your dog’s weight loss. Whilst some slow weight loss is normal in dogs, unexplained weight loss with an  increased appetite needs investigating.