Panting

Question
QUESTION: Hi! My 3 1/2 year old himilayan dwarf rabbit (2.2lbs)  has been panting for about 3 weeks now. It is gradually getting worse.

She has been battling a bacterial and fungal infection in the eye since the end of March (about 6 months) and was taking Difluctin (sp?) and Baytril up until about 3 weeks ago when she was switched over to a series of 2 eye drops. The eye infection has not cleared up yet, but that is a separate question.

In June she was diagnosed with GI stasis. It occurred very quickly. She had just finished up with dinner and a few hours later we noticed her laying on her side, lifeless and panting. She never lost her appetite and her poop size was normal until that night. We rushed her to the emergency vet where they gave her pain meds, fluids, and put her under a heat lamp because her body temp had dropped. When she was stable enough (2 days later) we transported her to her normal vet where she spent another night. She was sent home with Cispiride (.15mg) and Metacam (.10mg) twice daily until mid July when her dosages were reduced to once daily.

About 3 weeks ago (early-mid August) she began panting very heavy after dinner again - I thought for sure it was going to be another episode and trip to the emergency vet - but the breathing resolved itself in about an hour and she never became overly lethargic - she just looked very uncomfortable, laying on her side. This happened again the next night and we brought her to the vet the next morning.  Her lungs appeared clear, but her abdomen was not back to normal, however, it had improved since her last visits. Her stomach was also firm to the touch. From the Xrays in appeared that her heart was enlarged so the vet put her on Lasix. We took her to the cardiologist the following week, and he ruled out the heart, the xray was showing the pericardium and we took her off the Lasix. Her heart is functioning fine.

Since then her panting has continued to get worse. About 6 days ago she started picking at her food, and eating it very slowly. Then 5 days ago she stopped eating. We called the vet who told us to pick up Critical Care and resume the Cispiride and Metacam 2x a day. Her appetite came back 4 days ago and we did not have to administer the CC. Her panting, however, is getting worse. It is taking hours to resolve, if we notice it resolving at all. Last night she was out of her pen, binkying and panting. About an hour later she was laying on her side trying to catch her breath. We have been keeping her confined for the most part, but even at rest she is panting heavily. Do you have any idea what could be causing this?

ANSWER: Dear Kelly,

Since the vet noticed what appears to be an enlarged heart on radiograph, my top suspect would be a thymoma.  This is a malignancy of the thymus gland that does not tend to metastasize, but it *does* grow in a capsule until it can be so large that it seriously impinges on lung space.  We have had two rabbits die from this, and the only sign of trouble in advance was serious episodes of panting.

The stress can trigger ileus, so that could be a side effect of the main problem.

A thymoma can be positively diagnosed only via biopsy, but ultrasound and other more specific imaging can help.  

If your bunny is having more and more severe episodes, then time may be short to begin treatment.  Corticosteroids (e.g., prednisone) can help reduce the size of the mass to buy time.  But treatment involves either radiation therapy (with a veterinary oncologist) or thoracic surgery to actually remove the mass.  

If your bunny has a crisis and can't breathe, I have found that picking up such an afflicted bunny and holding her so her nose points downward (shifting the weight of her internal organs forward), it can also shift the thymoma away from the lungs enough to allow her to breathe better, at least for a while.

You can read more about thymoma in rabbits and find treatment options here:

http://www.rabbit.org/health/thymoma.html

http://www.rabbit.org/health/thymomastory.html

http://www.examiner.com/small-pets-in-dayton/thymomas-rabbits

I hope your bunny will be okay, but time is of the essence.  You may need to find a vet who is very experienced with rabbits for this, so check the referral listings here:

www.rabbit.org/vets

I hope this helps.

Dana


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

QUESTION: Thank you for this information. This is not something that I have yet found on
the internet, and another resource I will take with me to the vet when we go
in a few days, however, the cardiologist did say that he saw nothing abnormal
on the echocardiogram - would he have picked up a thymoma with this test?

Another thought someone else had mentioned was the possibility of Bloat.
Are you familiar with this? Could this be another suspect since her GI tract is
not completely clear?

ANSWER: Dear Kelly,

The echocardiogram is meant primarily to detect defects in the heart itself, and in heart function.  Since the thymus isn't part of the heart (it's located just caudal to the heart), it might not affect heart function at all until very, very advanced (to the point of interfering with heart function because of physical pressure).  At that point, it might be too late to treat.

If the vet saw what he thought was an enlarged heart, he might want to re-examine the radiographs and see if there is evidence that the "enlarged heart" is actually a thymoma partly obscuring the heart.  We are seeing this more and more in rabbits, to the point of my now telling people that this disorder is not "rare" but rather "uncommon."

:(

It's not a great diagnosis, but if it's caught in time, it is treatable.  I hope you can find a good, experienced rabbit vet who will know the best course of action for your bunny's situation.

Sending healing thoughts...

Oops.  Revising the last answer a bit.  I forgot to address your question about bloat.

I've seen true bloat several times in my life, and hope never to see it again.  In this condition, the rabbit's abdomen swells up to watermelon proportions and becomes rock hard.  This is due to the  buildup of gas and fluid in the *stomach* (not the lower GI tract), and the only way to stop it is to insert a nasogastric tube down the esophagus and into the stomach to relieve the pressure by draining fluid and gas.

Once a true bloat has progressed to the point where the bunny is really hard and huge, even relieving the pressure usually doesn't save his life.  The bunny can die later due to various things, from strain on the heart to necrosis of the GI tract.  In a true bloat, the condition must be caught and treated within the first hour or two (and sometimes it's not really even evident that it's a bloat at that point), or the condition is usually irreversible and fatal.

Since your bunny has recovered several times, I am not convinced this is a bloat--though I had one bunny who had a few "pre-bloat" episodes over the course of a few days  before she finally had the true bloat an died despite our tubing her and relieving the pressure.

So I *really* hope it's not bloat.  And from your description, I don't think that's it.  Your bunny would not likely still be alive if this were true bloat.

If you do think this is bloat, then you can sometimes short-circuit the gas and liquid buildup by laying the bunny on his *left* side and doing gentle abdominal massage.  This position relieves pressure on a very tight turn of the small intestine that's just distal to the pyloric sphincter (tail end of the stomach) and can sometimes allow the sphincter to open and release the bloat-building contents.

Hope this helps.

Dana

Dana

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

QUESTION: Thank you or your reply,
I will ask the vet when I see him NEXT saturday (the 1st appointment I could
get) about what you suggested, but is it plausible that this could be a side
effect of the medications? or the GI tract? or her eye infection?
Sincerely,
Kelly

Answer
Dear Kelly,

Without seeing your bunny, it's hard for me to make a judgment about this. It's possible that panting can be caused by pain.  But if this is chronic and even causing her to have seizures (possibly from lack of oxygen), I'd be more suspicious of a chest mass, such as a thymoma.

I have not heard of any medications causing panting like this.  I suppose it's not impossible, but it just doesn't seem very likely to me.

I hope she'll be fine soon!

Dana