Guniea Pig Hair Loss & Eating Hair

Question
My guniea pigs are two males- Buster & Gizmo.

About 2 months ago Buster started loosing hair, when I took them both to the vets the vet gave them an injection for mite infestation. Gizmo never really showed any effects however but his hair is very long and thick.

I took them back a week later for a check up and the vet said the problem was sold they were putting weight back on and not to worry.

Busters hair however hasn't grown back and although I haven't noticed him loosing any more he is not as big as he used to be.

They are eating and drinking normal and as content as normal.

I started to notice about 2 weeks ago , Gizmos hair looked 'trimmed'. Then I notice why when we had them out, Buster keeps eatng his hair. Not down to the skin but Gizmo is looking very trimmed compared to his messy self (hence the name Gizmo).

Will Busters hair grown back ?
Do they still have mites ?
Why is he eating his brothers hair?

Sorry a million and one questions.

Hope you can help, Leanne  

Answer
Dear Leanne,
I am not quite sure if they have mites or not.  However, if they are two males, you should not be keeping them in the same cage.  They will fight.  In fact buster may be eating his hair as a way of fighting, but perhaps not.  His hair will grow back, but do not keep them in the same cage any longer.  Take them to the vet again to get another check up and ask him for his suggestions.  Hope I helped!

-I.J.