Lice/Mites Suspected on New Rats

Question
Hello,

I have five resident females and three males. There were some rats at my local shelter. I wanted to adopt them, but have no friends or family to quarantine them. I told my husband not to get them unless he found a way to safely quarantine them. Well, lo and behold, my goofy husband brought them home anyway, even though I told him not to.

The rats from the shelter are a family. There is a mother, father, and two sons. The mother is a biter and has behavioral problems. I have had to tame gerbils, mice, and hamsters, but never a rat. All is going well so far. I read to her for a while, and offered a small piece of bread, which she took from me. I was pleased that she laid and ate outside of the house while I was reading to her. Her nervousness seemed to lessen as we went on. She seems fine sitting next to me on the couch (inside her temporary bin cage, of course -- I don't plan on getting her out for a while yet). I plan on continuing to read to her and offer treats for now. I don't want to introduce her to my females until I am able to safely pick her up, in case a scuffle needs to be broken up. The males on the other hand, are very sweet and don't mind being petted one bit.

I believe that the new rats have lice or mites, particularly the female. She scratches excessively and has given herself bald spots. So, according to what I have read, it would be best to treat all of the rats in the household now. Unfortunately, I have been having a lot of trouble finding a vet within a reasonable distance that is experienced with rats. I have been to the ones in my area that claim to treat them, and honestly, they don't know what they are doing; so I need help with home treatment. Because of our situation, I figure that oral Ivermectin is our best bet.

I have several questions. Does it matter which brand of Ivermectin we get? I know it supposed to be the 1.87% paste for horses. At what point in the treatment should I wash all of my rats' things thoroughly? We can't have our own washing machine because of the water setup at the place we are renting, so we have to go to the laundromat. Do you have any personal advice or suggestions? I have never had to treat for lice/mites before, so all information is appreciated. Thanks!

Answer
Though I have experienced many things with my rats over the years, I have not had to deal personally with the mites problem.  However, I am very familiar with it regardless and am prepared if I ever do have this issue, so I can definitely advise you.  

You should never use horse worming paste on a rat.  I recommend you go to your local vet and purchase a small vial of Revolution for kittens or cats. Never use Revolution for dogs as it is a different strength and will overdose your rat! You can treat at least three to four rats one time with one of these vials.  You need to know their weight or at least a really good guesstimate of their weight.   You will need a syringe with a removable needle (they all are usually removable)  You will not inject the rat, but you will need the needle to be able to poke through the top of the vial and draw out the exact amount of liquid needed to put on your rat.  Remove needle before applying the liquid.   It should go right behind their head, between their shoulders.   Part the fur to expose the skin and push the plunger down, squirting out the small amount of Revolution.   DO NOT let your rat wipe it off.  Keep her  busy for at least 15 minutes until it dries. Do not rub it in.  Also, don't let your other rats near her or they will lick it off.  

I hope this is helpful in treating your rats.  Please let me know if there is anything else I can help you with.