I am very sorry you are going through this.

The balance organs are located deep within the ears, in the so called labyrinths. The physical removal of the mass could perhaps have changed something in there. There is a big nerve, cranial nerve nr 8,  that conveys balance info. Sense of orientation in space is maintained with the help of a fluid called endolymph and calcium carbonate crystals within the labyrinth itself. A disturbance in this system could cause loss of balance, vertigo and nausea. This loss could be temporary, because the brain is often capable to get used to new conditions (habituation and desensitisation).

The symptoms of the e cuniculi parasite often involve the balance organs. The symptoms would be the same as when the bun has an ear infection, and you cant readily tell the difference without tests or by empirical treatment with medicines. Empirical treatment means you try a certain medicine without knowing exactly what the patient is suffering from. It is often done with human patients, for example when there is no time to wait for tests results or if tests for some reasons cant be done.

It seems likely that your bun’s problems are caused by the cancer, but its complicated by the fact that many rabbits carry the e cuniculi parasite, and this parasite often lies dormant until the bun is weakened by something else. When the bun’s immune defense is weakened, the parasite seizes the opportunity and starts to multiply and cause trouble.

To help your bun cope, he could benefit from meds to counteract nausea, such as metoclopramide and/or certain antihistamines, and a pain killer.

Did your vet tell you more about this cancer? Did they give you any idea of a prognosis?

Oh my, how scary, I’m so sorry. 🙁

I wonder if the removal of the tumor threw off his balance (since it was in his ear)? Extreme cases of head-tilt can look like this. Inner ear infections can cause ataxia (the rolling and stumbling you describe), so I feel like this is all be related to the mass in the ear, and possibly some swelling after it’s removal. From medirabbit (http://www.medirabbit.com/EN/Neurology/Otit/otitis.htm): “Inner ear infection is accompanied by ataxia (circling, rolling stumbling), leaning to one side and head-tilt. Some rabbit sway their head from side to side. This is caused by the pressure of the infected tissue and inflammation of surrounding tissues leading to the compression of nerves passing through the vestibular region of the brain.”

Is he on pain meds or an anti-inflammatory?

For now you should cushion his environment so he doesn’t hurt himself. You can add lots of towels and cushions to his area, and it would be best to confine him a bit so he doesn’t get too far away from his food and water. Here is some more info on managing this: https://www.mspca.org/angell_services/management-of-head-tilt-in-rabbits/

I think treating for EC concurrently is a good idea, just to cover the bases. It is thought that most rabbits carry EC, but may not be symptomatic. Something stressful like a surgery could cause a flair up, so treating for it won’t hurt.

Oh, looks like Bam and I were typing at the same time!

Hi Dana 😃

Cushioning his area and making other arrangements to keep him from hurting himself is a great idea!

I also agree treating for e cuniculi is a good idea, Panacur is a “mild” drug with few and rare side effects. It is slow acting though, so it can take weeks before you see improvement.

Meloxicam is a  good pain killer and anti inflammatory med that buns tolerate well. It can be given together with Panacur.

It’s possible that the tumor was putting pressure on something in the inner ear. Then when it was removed, the pressure was released and it is causing his balance issues. I agree with the others though. It doesn’t hurt to treat with Panacur just in case.