lumps under lop ears

Question
QUESTION: Hi Dr. Dana,
    I recently adopted a rescue bun....he's a 2 year old mini lop and he's developed these lumps right below where his ears join to his head. They seem to have gotten bigger over time....at first I thought they were part of his head, but one is ever-so-slightly smaller than the other.
   I took him to my vet today....she's seen some rabbits, but is not completely rabbit savvy. She took a sample from one of the lumps and there wasn't anything in there but red blood cells. She checked inside his ears and saw no evidence of infection, scabies, mites or wax build-up...and she looked way down in there.
   I should add that he shakes his head a lot and scratches at them some too.
   Other than that, he seems to be acting normal....eating, pooping, peeing, exploring....
   The vet advised warm compresses and said she would do some research. You have any ideas about these lumps?
  thankz a bunch,
     Ellen & Leroy, the bunny

ANSWER: Dear Ellen,

Though the vet saw no sign of infection, such bulges are very typical of a middle ear infection and the swelling that comes with this.  It's very, very common in lop rabbits, unfortunately.  Their ear canals are not open to the air, and are often pinched off by the position of the ears, creating a perfect environment for bacterial growth.

Please try to find a rabbit-savvy vet here:

www.rabbit.org/vets

and get your bun there for evaluation.  Head radiographs might be necessary to diagnose the problem.  In some cases, surgery is necessary to marsupialize (open) the ear canal so it can be flushed and drained and allowed to "breathe", but if this is what your bunny needs, then you likely want a vet who knows how to do it, and who is experienced with rabbit anesthesia and surgery.

One approach would be to try medical treatments first, and in many cases such abscesses may resolve with dual-acting Penicillin G Procaine/Benzathine (injection only!  no oral penicillins are safe for rabbits!), though it can take weeks or months to see improvement, and in a lop bun the treatments should be accompanied by flushing and debridement of the infected tissue as much as possible.

More information can be found here:

http://www.rabbit.org/journal/4-11/ear.html

I hope you and your vet will find it helpful.

Dana



---------- FOLLOW-UP ----------

QUESTION: Hi Dana and thanks for getting back to me,
   Could you tell me more about the "flushing and debridement"? I don't see any infected tissue, as the infection seems to be way down in there. What do I flush with and how often?
  At the suggestion of a Gainesville Rabbit Rescue person, I stuck my nose down in his ears for a sniff...why I didn't think of that, I don't know? They have a bit of an infected smell, especially the one with the larger lump. To make sure, I sniffed my healthy rabbit's ears so I'd know the difference.
   I'm calling my vet today about the penicillin injection...do they inject into the lumps or just systemically?
   thanks,
     Ellen

Answer
Dear Ellen,

If there is infection but it's too deep for you to see, then you might need to ask the vet about an ear flush machine.  You can buy these for home use, but they are expensive.  Alternatively, you can take her to the vet for regular flushes.  But I think in a case like this the first line of attack might be the dual-acting penicillin injections.  These are injected sub-cutaneously, and work systemically.  

Problem is that ear infections are often poorly vascularized.  So it helps to be able to actually remove the infected goo, if possible.  Some vets will perform a rather drastic surgery on lops--a marsupialization--that creates a slit to extend the opening of the bunny's ear.  You can see pictures here:

http://www.medirabbit.com/EN/Skin_diseases/Bacterial/Abscess/skin_abscess.htm

(the white rabbit about middle of the page)

Once healed, the increased opening allows easier flushing and debridement of infected tissue, and can help resolve the abscess.  

Hope this helps.

Dana