Puzzled by rabbit

Question
QUESTION: Hi Dana, I hope you can help.

I have a 3 year old male lop rabbit, and over the last month, his eyes appear to be bulging out of his head. When he is at rest and relaxed, they can look quite normal, but at times they appear to be bulging with the whites of his eyes showing. Over the last few days, he has also been making a strange grunting noise while he is eating and his nose has been whistling while he is breathing. This has been happening on and off over the last few days. I also think he has been holding his head in an awkward position at times, and has been finding it hard to groom himself (particularly in the genital area).

He was at our local vet today, and had an x-ray however the vet is completely puzzled by what is wrong with him. His teeth are fine and the x-ray looked normal. A small animal expert also examined him and couldn't work out what was wrong. They agree that it is not 'normal' but don't believe it's anything to be too concerned about.

Does this sound like anything you have come across before, or are you able to shed any light on what is going on?

Many thanks,

Laura

ANSWER: Dear Laura,

The most common cause of bilateral bulging eyes in rabbits is a mass in the chest that is impinging on the return blood flow of the descending aorta.  The blood backing up in the head fills the very large venous sinus behind the eyes, and causes the eyes to bulge.

Because such a mass may also be pressing on the lungs and/or trachea, it's not unusual for a bunny so afflicted to make noises when s/he breathes.

The masses that most often turn up in rabbits are thymomas, enlargement of the thymus, which sits above the heart.  On radiograph, this may appear to be simply an enlarged heart, or an indistinct mass above the heart.  

It is also possible that the bunny has an intra-thoracic tumor or abscess that's having a similar effect as a thymoma would.  I would suggest you find a really experienced rabbit vet:

www.rabbit.org/vets

and get a second opinion.  Vets who see mainly cats and dogs may not be aware of the thymoma condition that we are starting to see more and more often.

It can be treated in various ways, but first diagnosis must be made.

I hope this helps.

Dana

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

QUESTION: Thanks very much for your help Dana - I'll certainly be taking your advice.

Laura

Answer
Dear Laura,

If it does turn out to be a thymoma, please write back to me.  I can put you in touch with people who have successfully treated the condition with radiation and other medical treatments.

There is one vet in the UK who has actually surgically removed a thymoma, but if you're not in the UK, it would be quite a commute. And the other therapies would probably be best to try first, anyway.

Sending healing thoughts...

Dana