Rabbit has large growing lump

Question
My rabbit has developed a lump behind his left ear. We noticed it a few months ago and took him to a traveling vet. He lanced it and it just had pus in it. He told us to keep it clean and let it drain out. It didn't take long for it to close up though and now we have no way of letting it drain. It has since grown and sometimes will crack and bleed slightly. Though if you move it he doesn't act like it hurts at all.  No vets around here will treat rabbits and we are unsure of how to go about treatment since it is continuing to grow. Thank you for any advice.

Answer
Dear Sarah,

An abscess like this cannot simply be lanced and drained in a rabbit, as it can for a dog or cat.  Rabbit pus is extremely thick and caseous (literally, "like cheese") and it doesn't drain.  You need to find a vet who can surgically remove the abscess completely, or even surgically open the ear canal to allow constant pus removal and flushing, if the infection is not encapsulated and possible to remove as if it were a tumor.

At the point of removal, a sample of the outside of the abscess should be taken to send to a lab for culture and sensitivity testing:

www.bio.miami.edu/hare/culture.html

This will tell the vet the appropriate antibiotic to use to resolve this infection, which is painful even if the bunny is being stoic about it.  He also will need pain medication.

Please try to find a good rabbit vet within driving distance here:

www.rabbit.org/vets

It will be worth a trip to get this properly treated.

I hope this helps.

Dana