Fallen Ear

Question
QUESTION: Hi- We recently adopted a bunny around 6 weeks ago and he is estimated to be around 2.5 years old.  (We already have 3 buns who are bonded... all four are "fixed.")
Our new boy came to us with chin abscesses and he is being treated with Penicillin Q injected and that has been going on for around 5 weeks or so.  (We treated the open abscess after surgery with manuka honey).  
We started bonding him to the other 3 around a week ago and shortly after he went in with the others, one of his ears fell.  I play with his ears a lot and was worried that I damaged his ear, but our vet tech didnt think that that was the case when I brought him into the vet 2 days ago for a check up on the abscess issue.  His ears are clear with no evidence of infection.  The bonding is going very well with everyone relaxing together and lots of grooming.  (a little peeing on the floor still... but thats getting less frequent.)
Now his ear has been down for a week.  
Could I have damaged it?  Would it have gotten worse if he had a parasite?
He doesnt seem to be in any pain at all and he isnt scratching at all.
Thanks!
Alison

ANSWER: Dear Alison,

I really doubt that your playing with his ears could have damaged the cartilage unless you actually picked him up by the ears (I'm sure you know this is a big no-no).  What's more of a possibility is either

1.  an incipient ear infection or
2.  early signs of E. cuniculi, which can manifest with an ear falling and then, later, a slight head tilt.

That he's not scratching it makes me worry more that it might be #2.
Even if he doesn't have a full-blown head tilt, some of the causes of "falling ear" and head tilt are the same, so I'd recommend you read:

www.rabbit.org/health/tilt.html

and share it with your vet, if s/he is receptive to such things (the article was written by a rabbit expert vet).  Your vet may want to have a look deep in the ear for any sign of infection (which is more likely if he has a history of jaw abscesses, but now there may be a new population of bacteria growing that's not susceptible to the penicillin), and/or may want to start him on Panacur (fenbendazole) and/or ponazuril, in case of E. cuniculi.  The latter should be treated early, since neurological damage is not reversible.

I hope this helps.

Dana

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

QUESTION: Thanks for your input- i will ask our vet about doing a deeper ear exam and the medication.  
BUT- his ear went back up at some point last night after being down for an entire week!  (any thoughts?)
Thanks so much for your information- it is very helpful!
Alison

Answer
Dear Alison,

Hmm.  When a bunny starts to show signs of E. cuniculi, they can come and go.  This includes weakness in the back end that seems obvious one day, and fine the next.

So I'd still take him to the vet and tell the vet exactly what you observed, and ask about E. cuniculi.  Better to be safe than sorry.

Hope he'll be completely fine, and this was just a false alarm.

Dana