Rabbit predisposed to stomach blockage?

Question
Hello,

We have a 2.5 year old dwarf mix rabbit. He eats Oxbow Bunny Basics and timothy hay with vegetables most nights, has a bonded partner, and is the most loving and sweet rabbit anyone could ever know.

Shortly after he turned two, he got lethargic and stopped eating (he had not ever had medical issues before this; he was always very healthy in exams). We took him to the vet, who did an x-ray which showed he had a complete stomach blockage (the intestines were not blocked, but the valve at the end of the stomach just before the intestines was completely covered). She was able to diagnose this because of the look of the stomach on the x-ray - enlarged and ringed with ingesta - and the location of the bubble of gas - large and in the center of the stomach. She called this a bulls-eye pattern. Our choice was to have him tubed, where they sedated him (not entirely under) and tried to pull any of the gas or ingesta out of the stomach to relieve the pressure. They were able to remove some gas, some fluid, and some hair. Apparently this was enough of the blockage, and he was able to make a recovery after a few days in the hospital and a week or two of intense care at home.

About two months later, the same thing happened. This time, it was concurrent with us noticing sludge in his urine. We took him in to deal with the sludge, and found out the same blockage was occurring. It was much earlier this time, so his condition was not as severe, however we did the same tubing procedure as we were told it was only a matter of time before he was in as bad of a condition as he was last time. Again, after some time in the hospital and care at home, he recovered.

Now, less than 6 weeks later, it is happening again. Since the last attack, we have been giving him petromalt/laxatone as a preventative, we have changed the type of hay he gets (to Oxbow's Botanical Hay, which seems to make him eat more hay because he never really ate as much hay as our other rabbits), he gets Mylicon, Metacam, and Sub Q fluids at the first sign of any trouble, we make sure he gets exercise, and we are vigilant about minimizing the amount of hair he ingests. Our vet also prescribed Prozyme everyday to help dissolve blockages. But despite all this, it's happening again.


So we have these questions:

1. Is he just predisposed to stomach blockages? Why didn't he have any until he was two? And now, why three in less than six months?

2. What else can we do to stop this from happening? Getting him tubed is stressful for him (and us!), and very expensive. Also, if we aren't extremely vigilant, we could lose him before he can get to the emergency vet.

3. Is the sludge a contributing factor?

4. What else can we do? We're at a loss to know what might help him.

Thank you so much for your answer,
Dawn

Answer
Dear Dawn,

This is a terrible problem.  You might be surprised to hear this, but your bunny is actually lucky to be alive.  Most rabbits do not survive a true bloat (stomach blockage) and it's a tribute to the vigilance of your vet that your bunny came through and recovered.

I'll take your questions one at a time here:

1. Is he just predisposed to stomach blockages?

Sadly, it sounds as if he is.  It is quite unusual for a bunny to suffer this many episodes in such a short time. There may be something unusual about his anatomy that keeps causing this to happen.

2.  Why didn't he have any until he was two? And now, why three in less than six months?

This is a good question.  I have to wonder:  is there a possibility that he ingested something synthetic in the last few months?  Carpet?  Foam?  This will not be digested, and will just stay in the stomach, waiting to cause a potentially deadly problem.

If not, then it could be just a side effect of his mature body, now fully developed.  He may have an unusually tight "hairpin turn" of the intestine just caudal to the stomach.  Rabbits all have a tight turn there, but most don't have problems.  But in some rabbits, if the stomach gets gassy or filled with fluid (due to something blocking the pyloric sphincter), the increased size of the stomach can actually pinch off the intestine at that turn, causing a bloat that is irreversible without tubing.

It can help to turn the bunny on his *left* side and give gentle, vibrating massage to try and relieve the pressure.  The stomach will fall away from the hairpin turn if he's on his left side, due to gravity. But if the stomach is already very large, this won't work.  

3. What else can we do to stop this from happening?

Unfortunately, this is hard to know for sure.  Gas meds are a good idea.  Feeding him small quantities at a time is also good, since you don't want to overfill a stomach that's prone to bloat.  The enzymes your vet prescribed are all good ideas.  Oral hydration to help prevent the mass of stuff in his stomach from glomming together will also be good.

4.  Getting him tubed is stressful for him (and us!), and very expensive. Also, if we aren't extremely vigilant, we could lose him before he can get to the emergency vet.

Yes, that's absolutely true.  Treating a bloat within an hour of onset is pretty much the only way to save the bunny's life.  Once the gut h as been pinched off too long, it can become necrotic and then the bunny may die a few days later, even if the bloat is circumvented.

I have only one more thought here, and it is an extremely aggressive measure.  I am completely *against* gastrotomies for rabbits, because they usually are done unnecessarily, and they are a surgery that is not often survived.

But if this keeps happening, and your vet suspects there is a permanent mass in the stomach that keeps moving around and blocking the pyloric sphincter, then one option is to do a gastrotomy next time he bloats, and remove whatever is causing the blockage.

The problem here, of course, is that there might not *be* a permanent mass in the stomach.  It might be dissolving and re-forming regularly.  No easy way to know.  So maybe ask the vet what she thinks about this.  I would do it *only* if the vet feels there's a real chance that there is some permanent mass in the stomach that's causing these chronic episodes.  The surgery is very risky.  One vet I know who claims 100% success in gastrotomies has a "secret weapon":  before closing up the stomach after surgery, he fills it with Critical Care.  This seems to "jump start" the gut, since a rabbit's stomach is normally never empty.

If you ever decide on this very aggressive option, this might be something to mention to the vet.

5. Is the sludge a contributing factor?

I doubt it.

5. What else can we do? We're at a loss to know what might help him.

I think you're doing all the smart things. Oral hydration is important, to keep things moving freely through the stomach.  Gas meds. Enzymes.  

But the main thing is vigilance:  at the very first sign of another bloat, he needs to get to the vet to avoid a potentially fatal outcome.

I hope he won't suffer any more attacks, but if he does, I hope some of this helps.

Dana