From old age to fussy eating habits – how to identify the reason for weight loss and get your dog back on track

Why is my dog losing weight?

Quick takeaways about dog weight loss

  • An insufficient diet, dental problems, stress and health issues could all cause weight loss.
  • You can check if your dog is too thin by using the Body Condition Score (BCS).
  • Speak to a vet about sudden weight loss or if they’re still eating and drinking as normal.

It can be worrying to see your dog losing weight without knowing the reason – whether it’s sudden or gradual.

To work out how to help them put weight back on, you need to understand why your pooch dropped kilos in the first place.

From health conditions to behavioural issues, age to environment – so many factors might cause your dog to lose weight.

But, with the correct diagnosis and the right diet, you can help them get back to their healthy, happy selves.

Common causes for dog weight loss

Your dog’s weight loss could be down to several reasons. Here are some of the biggest causes:

1. Diet

Your dog’s food might not meet their nutritional needs or give them enough calories for their size and activity level. They could also be a fussy eater.

Always opt for high-quality dog food and check that you’re feeding the correct amount for their weight.

From health conditions to behavioural issues, age to environment – so many factors might cause your dog to lose weight.

You could always up the amount of food for a little while to see if it brings their weight up to a healthy number.

2. Dental problems

Abscesses, inflamed gums and dental disease can make eating painful and reduce your dog’s appetite.

If you’re worried there might be a problem with your dog’s teeth or gums, speak to a vet.

Some issues are really hard to see without a professional eye, so it’s always worth a quick check.

3. Environmental issues

Is there another dog or pet in the home that could be eating your dog’s food before they get the chance to?

Do they have a calm safe space to eat their food in peace? Sometimes, the situation at home might be impacting your dog’s appetite.

4. Age

Dogs can lose muscle and body mass in their senior years.

If your older dog is losing weight despite being on the same type and amount of food, it might be time to switch up their diet and increase their calories to help them stay healthy.

5. Parasites

If your dog has an intestinal parasite or worms they might lose weight – even if they’re eating normally. This is because parasites take nutrients away from their host animal.

Make sure you keep up to date with your dog’s worming treatment. And, if you see worms or strings of white in their poo, get them checked out by the vet.

6. Diabetes

Dogs with diabetes pass sugar through their pee because they can’t process it without insulin.

This means they may not be consuming enough calories and instead use their fat reserves, which can cause weight loss.

Other signs of diabetes in dogs include excess water drinking, increased pee and cloudy eyes, so speak to your vet if you’re worried.

7. Stress and anxiety

Your dog might lose their appetite if they’re feeling very stressed or anxious.

Your dog could be naturally highly strung or sensitive – or changes like new babies and pets, or moving home could affect them, too.

If you think your dog might be experiencing either, then speak to a vet or a registered behaviourist to help find out the cause and how to help them feel calmer.

8. Arthritis

This common condition can make exercise and moving around painful. It can affect older dogs and is more prevalent in specific breeds like Labradors and German Shepherds.

Reduced activity levels can lead to muscle wastage (and sometimes weight loss) in dogs.

9. Gastrointestinal disorders

Issues affecting the digestive tract like inflammatory bowel disease (IBD), severe food allergies and liver disease can reduce your dog’s appetite and their ability to take in nutrients.

Weight loss on a raw food diet

“Many dogs can naturally lose weight when moved over to a raw diet,” explains veterinary nurse and educator for Natures Menu, Melanie Sainsbury.

“This is often mostly due to their previous diet. They were likely eating a dry food diet (like kibble) which is usually naturally higher in carbohydrates and will increase their weight.

“When your dog starts eating a high protein, low carbohydrate food like raw, it can often take a few weeks or months for their body to adapt.”

But the benefits will begin to show much earlier than this!

When to speak to a vet

Regularly checking your dog’s weight will help you identify weight loss or weight gain early on.

Changes in diet, age and exercise can all lead to gradual weight loss and are usually nothing to worry about. Check if your dog is still eating normally or if you’ve noticed a loss of appetite.

But, if the weight loss is coupled with physical or behavioural changes or other signs of illness, however, it’s best to get it checked by a vet as soon as possible.

If the weight loss is sudden, always speak to a vet – especially if your dog is still eating and drinking as normal.

A vet will look at other potential signs of illness or behavioural changes. They’ll consider your dog’s medical history, age, diet and calorie consumption.

Depending on the reason, your vet may simply suggest a change in diet to help your dog regain weight.

This could be a general high-calorie, nutrient-rich diet or a diet specific to a particular illness or condition – like hepatic diets for pooches with liver issues.

Other symptoms to watch out for

Physical symptoms to watch out for include if your dog is losing weight and hair, if they appear lethargic or if they have become more or less active.

Check whether your dog is peeing more often, if their poo has changed or if they’re vomiting daily but acting normal. These are all reasons to speak to your vet.

Bad breath, excessive drooling or red, swollen gums could also indicate dental problems.

How to check your dog’s weight

Check the ideal weight for your dog’s breed and gender, then weigh them using some scales to see how they compare.

It might be easiest to do this at the vet – there are usually scales in reception or book an appointment to get it checked.

You can also check their Body Condition Score (BCS) by looking at your dog and using this chart.

Weight guide

The ideal weight is in the middle, with underweight and overweight animals scoring lower or higher.

A healthy dog has a slight hourglass shape when looking from above. From the side, your dog’s torso should gently angle upwards towards their hind legs.

You should be able to feel their ribs and backbone as well as a thin layer of fat cushioning them – similar to the feel of knuckles on a hand lying flat.

If the bones feel like knuckles on a closed fist, it’s likely your dog is too thin.

How to help your dog gain weight

If it’s just age or a lifestyle change – and nothing else is wrong – you can help your dog put on weight from home.

Switching to a high-protein pet food should help your dog regain weight. Our meal plans with raw food nuggets could be a great solution.

The Complete and Balanced meals have been carefully crafted to contain the right balance of meat, veg and fruit to give your dog everything they need to be happy and healthy.

“As mentioned above, sometimes dogs can lose weight when they start to eat raw – this shouldn't be excessive, they might just develop a waistline that you might not be used to seeing,” says Melanie.

“To help prevent weight loss in cases where it’s not needed, feeding a healthy carbohydrate alongside their raw diet can help. Things such as cooked brown rice, rolled oats or cooked sweet potato can all help to maintain and gain weight.”

You can also increase nutritious treats like cream cheese, sprats, or treats like our meaty treats and superfood bars.

Try to help your dog continue to exercise too, as this builds muscle mass and increases their appetite.

If you think anxiety might be an issue, try establishing a good mealtime routine in a calm room away from other animals or distractions.

It might be worth speaking to a vet or registered behaviourist if you’re worried that your dog’s mental health might be affecting their appetite or weight.

Try our personalised meal plans with high-quality raw ingredients to help keep your dog healthy and happy.