Chihuahua pup with "balding" in black areas only?

i don't know anything about the alopecia, but what do you feed her? a dog's diet can have an effect on the quality of their coat. try feeding a high quality dog food, one that is high in protein and grain free. the food that i feed my dogs is Taste of the Wild. it is appropriate for all ages and is a great high quality food. you can find where they sell it near you using this website:

http://www.tasteofthewildpetfood.com/dealer_locator/

you can also feed her raw egg yolks in her food, or add fish oil vitamins to her food. both help to make the coat shiny and soft. the fish oil also helps with skin issues.

as for figuring out what it is, i'd seek a second opinion from a different vet and see if they have any options for you.

for the alopecia, the vet can do a biopsy to diagnose it, but the treatment isn't usually successful. this is a genetic defect and not much can be done for it.

http://en.wikipedia.org/wiki/Canine_follicular_dysplasia

this is the site on wikipedia that i found. i'd try switching her diet to see if it helps. if you decide to do this, if there's going to be improvement, you should see it in about a month.

http://www.petplace.com/dogs/alopecia-in-dogs/page1.aspx

here's another site on alopecia. it doesn't say anything about black hair alopecia, but it has some things that could be the underlying cause. you should do a follow up with your vet. alopecia can't be treated until you diagnose the underlying cause for the hair loss....Show more

I have a Chihuahua who has "clipper alopecia" when I had her spayed, the area that was shaved never grew back.

There is probably nothing that you can do about it, if it is a form of alopecia....Show more

http://en.wikipedia.org/wiki/Canine_follicular_dysplasia It appears it's a genetic condition that tends to get worse....Show more