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My dog's not losing weight on prescription food. What can I do?

Updated On September 23rd, 2025

Pet's info: Dog | American Staffordshire Terrier | Female | spayed

My one dog has been on prescription weight management dog food for about 8 months and she is not losing any weight. She needs to lose about 20 pounds. I heard that dogs being on a vegan dog food can help them lose weight. Is that true? I have my other two dogs on a vegan diet due to medical and allergies. I was wondering if it would help her lose weight or what is something I can do to help her lose the weight?

5 Answers

Most Helpful Answer

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Answered By Sarah Derksen, DVM

Veterinarian

Published on January 4th, 2018

Hi. Great job trying to get some weight off of her. A few recommendations....pets are NOT vegan. So it is not recommended for pets to be on this type of diet. If there is a food allergy, she should be on a prescription dog food prescribed by your veterinarian. Pets are usually 93% of the time allergic to the protein source, not carbs. So chicken or beef, etc. Therefore, a different protein source such as fish or other novel proteins are recommended. With weight problems, you will want to cut back, or stop all treats and people food. Some pets don't lose weight if they have metabolic or endocrine conditions. The most common is a low thyroid. So getting her thyroid checked is an important step. Also increase exercise as much as possible. Lastly, have your veterinarian give you a recommendation bases on weight for the amount of dog food she should have per day. Good luck.

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Related Answers from Veterinarians

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    Answered By Sarah Derksen, DVM

    Veterinarian

    Published on

    Hi. Great job trying to get some weight off of her. A few recommendations....pets are NOT vegan. So it is not recommended for pets to be on this type of diet. If there is a food allergy, she should be on a prescription dog food prescribed by your veterinarian. Pets are usually 93% of the time allergic to the protein source, not carbs. So chicken or beef, etc. Therefore, a different protein source such as fish or other novel proteins are recommended. With weight problems, you will want to cut back, or stop all treats and people food. Some pets don't lose weight if they have metabolic or endocrine conditions. The most common is a low thyroid. So getting her thyroid checked is an important step. Also increase exercise as much as possible. Lastly, have your veterinarian give you a recommendation bases on weight for the amount of dog food she should have per day. Good luck.

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    1Pet Parents found this answer helpful

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    Answered By Laura Johnson VMD

    Veterinarian

    Published on July 11th, 2017

    Hi, I'm Dr. Johnson. Thanks for using Petco Pet Education Center, formerly Petcoach! I understand your frustration! Trying to get pets to lose weight is hard! There are metabolic changes that can occur when dogs age that can predispose them to weight gain. The most common is hypothyroidism ( low thyroid). Dogs can exhibit heat seeking behavior, act more lazy, have skin issues and gain weight with a low thyroid. If you are struggling with her weight you can have your Veterinarian test her thyroid. At home, I'd try to eliminate as many treats as possible especially things like rawhides, which contain a ton of calories. Limit or eliminate table food. Try to slowly cut back the amount of dog food you feed her by 25% and replace the missing volume with green beans. Try to increase activity. As for eating paper towels and toilet paper-some dogs just have a desire to tear it up and eat it. I don't think it's contributing to her weight gain. Just be careful about how much paper she eats it could cause GI upset or an obstruction. I wish you and Aysha the best of luck!

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    1Pet Parents found this answer helpful

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    Answered By Dr. Elizabeth

    Veterinarian

    Published on March 7th, 2019

    Obesity is a common pet problem now. You can get her weight down with portion control. Most dogs eat about 1 cup per desired 20lbs of body weight per 24hrs but this is just an estimate. Treats and human food can also add a surprising amount of calories and so to achieve weight loss, these need to be eliminated or modified to low calorie treats and taken into account with the over all calorie intake. Over the counter diet dogs foods can help dogs who are 10-20% over weight but higher than that, a prescription food really is best. For over the counter diet I recommend science diet or Royal Canin. For prescription diet you will need to talk with your veterinarian. Lastly if you were doing everything right and Kiro is not losing weight, it could be a thyroid disorder which is diagnosed with a blood test. As you already know, try to keep her active as this will help weight loss as well. I hope this helps and please feel free to post any additional questions.

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    Answered By C. Rathjens, DVM

    Veterinarian

    Published on September 18th, 2018

    It's great that you're looking in to getting her weight down! Well done. It's most effective to decrease food intake while increasing exercise. So I'd taking a day or two to write down everything that goes in her mouth so you can find all the little treats that you give her that might add up. Then talk to your vet about how many calories she should be eating to be her ideal weight. If you can't talk to your vet, you can start by decreasing her food 10%, but I recommend talking to the vet because that could be way too little or too much for her body. I also recommend making her regular treats tiny (pea size) so she's getting less calories, but you both still get to enjoy the treat giving! As far as walks, if she's otherwise healthy, you really can't walk her too much. Add 5 to 10 minutes to your regular walk every week until you're at the point where you don't have additional time to walk. Oh and take before and after pictures! They are so fun. Good luck and thanks for using Petco Pet Education Center, formerly Petcoach!

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