Hairless rat with tail abscesses

Question
I have had 11 pet rats over the last 10 years.  I currently have a two year old hairless pet rat with a problem that is new to me.  He has gotten little abscesses all over his tail.  I took him to the vet, not knowing what they were and she put him on oral antibiotics (sulfamethoxazole) and Silver Sulfadiazine salve twice a day.  My vet is excellent and has rats herself, btw.  There was improvement at the check-up, but not resolution.  I switched to Healx cream and that helped with the healing.  He has been done with his oral for a few weeks and he is starting to get new little abscesses and his old ones have still not healed and have little scabs.  Are tails usually slow to heal?  Scratches he has received on his back heal much quicker.  He has not had any abscesses on any other part of his body, only his tail. He does have young cage mates, but the sores started before they were introduced.  I am going to trim their nails, since they have scratched the hairless rat and may be the cause of the new sores on the tail.  Any ideas on how to get his tail abscess free?  I am getting frustrated, as is my little guy who hates to have his tail messed with!  Any insight you may have would be much appreciated.  Thank you!

Answer
Hi

Staphylococcus aureus is a common bacteria that is found to cause abscesses on tails. There are a few things that can be done to prevent them, starting with keeping him on a long term antibiotic given once daily to see if this keeps him from getting more.  While on a long term antibiotic it would be a good idea to also use a probiotic to provide him with any lost "good bacteria" after he has been on long term treatment for more than 30 days.  You can pick this up at a health food store or better yet, from the vets:)

The next thing to look into is the etiology and possible host factors.

Hairless rats are often born without a thymus gland, making their immune system a bit weaker. If perhaps he is exposed to an over abudance of staph, which is, by the way, normal skin flora found not only on humans but on rats as well, this may be the cause of the tiny abscesses to form, esp if the immune system is weaker than normal.

How long between outbreaks does it take for him to develop new ones?