What are reasons my Chihuahua is so underweight and what can I do to help him gain weight?

He is active and doesn't seem to be sick. He is just really skinny. And he won't eat very often.
If he is really tiny(as most Chihuahuas are) then he needs to be fed a food formulated for small dogs. Pet Smart, good pet stores, livestock feed stores and sometimes Wal Mart will have a dog food formulated for small breed dogs. If he is under 1 year of age, then feed him a small breed puppy formula. If you are feeding him people food then stop! He is too small to get enough of the nutrition he needs. The exception to this is with all my small dogs as they are growing, pregnant or just for a treat-I will give them 1 spoonful(not a scoop) of vanilla ice cream. Buy the good natural ice cream or you are just wasting your money. And only vanilla. You can also give him a spoon of cottage cheese-sometimes that will perk up their appetite. But keeping him on dry small breed dog food is much better than anything else. Can food is ok to mix a tablespoon in if they are picky, but not as a staple diet.

I think Royal Canin makes a feed formulated for Chihuahuas, if not there is one for Yorkies that would work-or my favorite is called Baby Dogs. It's really tiny kibble and works well for tiny puppies and their moms.

Another trick I have used is to offer them a little goat's milk-not cow milk, cream or half and half. goats milk is high in butterfat and helps to gain weight. However if he is not used to it, he may get some scours which you dont want.

Try the small breed kibble first, with maybe a spoon of ice cream in the evening after. And totally cut out the treats, people food or anything else that may cut his appetite.

Best of luck! Sheri
ps-you can go online to talk to Royal Canin advisors, or email me and I can get you in touch with someone. Purina, and Iams dog foods also should have professionals to speak to and I can find their numbers as well. *No I do not work for any of them-but did work in an upper end feed/vet store for many years.
What kind of food are you feeding? Buy another brand.
feed him more food, and also consult a vet.
Take him to a vet and stop eating his food.

There are a few things that can keep a dog underweight. High metabolism is one; if he is very very active then he needs more calories to keep weight on. The food you are feeding would be another factor. Another factor would be if he is intact or not/if he is neutered. Non-neutered males tend to be thinner as their metabolisms are higher.

Also, and the most important, is to be sure he is healthy on the inside as well as the outside. Have your vet examine him, do some routine lab tests (fecal, heartworm tests, etc.) to determine his internal health status.

If everything checks out OK, then he may just be a thin dog. Many times what looks to be thin, is actually a good weight. An ideal weight for a dog will be reflected in his body condition:

You should be able to easily feel his ribs and his spine without seeing them so easily. Meaning, his ribs and spine shouldn't be poking out so much, but you should be able to run your hand down his back and along his sides and feel the spine and ribs without having to rub hard. If you have to rub and poke, then he's too overweight. If you can see the bones very easily, then he is underweight.

Many of us are so used to see overweight dogs that when they are of an ideal weight, we think they are too thin.
maybe go see a vet and ask him why he is so under weight the vet may give you a special food. I do not think you should worry to much a quik stop at the vet should make him be just fine.
Find a better quality food.

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