Wild rabbit ear problem

Question
We have a couple of wild rabbits living in our backyard - one has a condition that I'd like to know if it could spread to domesticated animals (a neighbor has a pet rabbit).  This rabbit has large growths around its ears - dark colored and very large.  On one ear, they are around the base of the ear.  On the other, they are midway up, and the weight of the growths is such that the ear flops down and can't stay upright.  It looks like it feels okay - clear eyes, grooms itself well, active.  Thanks.

Answer
Dear Dulcey,

Without seeing the lesions, it's very difficult for me to guess what they might be.  They could be abscesses, tumors, neither of which would be contagious.  They also could be the cysts of botfly larvae (usually Cuterebara sp.), which will shrink up and heal when the larvae exit the cysts to pupate.  But without seeing them and examining them close up, I am merely guessing.

Botfly larvae ("warbles") are pretty common in wild rabbits in certain geographic areas.  They are not *contagious*, but if you have botflies in your neighborhood that are infecting the wild ones, they also can attack a domestic rabbit housed outdoors.  Revolution (selamectin) can help provide some degree of protection, as it may prevent the larva from growing.  The drug paralyzes certain types of invertebrates  (notably mites, roundworms, and a few insects), killing them without harming the host (as long as the blood/brain barrier of the host is not damaged, as from head trauma or congenital problem).  

I hope the little wild bunny will be okay.  Sometimes the botfly cysts become infected, but if the cottontail is otherwise healthy, we can hope that he'll withstand this parasite and make a full recovery.

I hope this helps.  Please write back if you have any other questions.

Dana