hair loss with sores

Question
What are the steps in making a diagnosis?  Do I need to have a skin scraping done?  I don't have any vets in may area that know much about caring for rats. I want to make sure I treat them correctly.  Dena   
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The text above is a follow-up to ...

-----Question-----
I have two rats that both are experiencing hair loss with sores.  At first it was just one of them that had the problem but now both are having problems.  They don't fight.  The hair loss seems to be just along their backs.  They do have very sharp nails.  They don't seems to groom each other overly so.  They scratch a lot but I don't think excesively.  They seem to be healthy otherwise.  Not sure if it's a skin problems or diet or something else.  I would appreciate any sugestions you could give me.  Thank you,  Dena
-----Answer-----
Dena, it sounds like your rats have mites. You can't see the little bugs, but you can see the damage that they do in the way of claw scratches, scabs, sores, and hair loss.

Mites on Rats
http://www.rmca.org/Articles/bugs.htm

More info:
http://ca.search.yahoo.com/search?fr=slv1-mdp&p=Rats%20with%20mites

A common method of ridding rats of mites is with the use of Ivermectin. I'm sorry but it would be irrisponsible of me to give directions for the general public for the use of Ivermectin as it requires careful administration. E-mail me for directions.

More info on the use of Ivermectin:
http://ca.search.yahoo.com/search?fr=slv1-mdp&p=Treating%20rats%20with%20Ivermec.
Or your vet can give the rat Ivermectin injections.

You might want to use the Holistic approach and for this I use Dr. Goodpet products:
http://www.goodpet.com/library/pharmacyFiles/flea.asp
http://www.goodpet.com/library/pharmacyFiles/scratch.asp
http://www.goodpet.com/library/pharmacyFiles/calm.asp
I get my Dr. Goodpet products from Wal-Mart.

spazrats
http://spazrats.tripod.com

Answer
Hey Dena, sorry for the delay in getting back to you.

Too many times a skin scraping will result in a false negative because the mites live under the skin where they can't be detected. So you go home from the vet's office thinking you are in the clear, but the poor rat is still suffering the affects of mites.

The simplest diagnoses is one dose of Ivermectin. If the rat has mites you will see a dramatic change in her within a couple of the days. If it wasn't mites there will be no change in her condition.

Ivermectin is a horse wormer. You need to find a brand that contains only Ivermectin and no other ingredient. The brand I use is Panomec
http://greenhawk.net/cgi-local/SoftCart.exe/scstore/p-SUW7901.html?L+scstore+hvd

spazrats
http://spazrats.tripod.com