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My large puppy is skinny. What food is best & when to switch to adult?

Updated On September 23rd, 2025

Pet's info: Dog | Mixed Breed Large (61lb +) | Male | neutered | 6 months and 30 days old | 55 lbs

I have recently adopted a dog. He is a mixed breed-shepard. At 6 months he weighed 50 pounds and he is currently going on 8 months old. I’ve been feeding him the Merrick grain free puppy beef and sweet potato all breed food. The kibble is small. He is getting 4 cups a day. He’s still skinny and eats it quickly. is there a more suited food for him? And when should I transition him to adult food?

1 Answer

Most Helpful Answer

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Answered By Dr. Elizabeth

Veterinarian

Published on August 2nd, 2019

Yes, there are diets better suited for Storm. Any dog who is expected to be over 55lbs as an adult should eat a large breed puppy formula. These foods are designed to control the growth of large breed puppies and help to avoid growth abnormalities like dysplasia. Also, most vets do not recommend a grain free diet unless a pet has known grain allergies. While it is not understood, there appears to be a link between grain free diets and some pets developing heart disease. Make sure storm is current on his deworming. Worms and other intestinal parasites will steal nutrients and make pets thin. A few other things to consider, Shepherds and Shepherd crosses are often naturally thin dogs. Some of his body structure may be normal for him. At his age, being lanky is also normal. Storm is essentially a teenager right now and he will not start filling out until 1 year of age. Don't be in a hurry to put weight on him. As long as he is eating a good food and eating enough food, he will fill out. Without a photo, it's impossible for me to know if Storm is too thin. I recommend to discuss this with his veterinarian and also remember to check his body condition score. Check the bottom of this link: https://www.petcoach.co/article/how-do-i-determine-if-my-dog-is-overweight/ The diets I recommend most are Royal Canin and Purina ProPlan. Both of these diets contain high quality, easy to digest protein and they have good quality controls. Storm should transition to a large breed puppy formula and eat this duet until he is 1 year old. The amount of food to feed is based upon the calories and he may need more than 4 cups but the package will tell you how much to feed based upon age and body weight. When he is 1 year old, he should eat a large breed adult formula. I hope this helps and please feel free to post any additional questions.

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