It's definitely not just a cat issue. I've had 3 rabbits that had it. And you can see in the articles I posted above that it's a known medical issue with rabbits. Which leads me to believe that maybe that vet isn't particularly knowledgeable about rabbits.
If you have other options for a better and more knowledgeable rabbit vet, that might be worth looking into and getting a second opinion, if you feel it would help. There's a couple listings for your area, but even if a vet is shown as seeing rabbits, doesn't necessarily mean they're a really good rabbit vet. So it might take a bit of research to find a really good one. It may also take traveling a bit to get to a better rabbit vet. For more advanced testing if needed, UC Davis is a possibility, though a bit of a drive.
https://wabbitwiki.com/wiki/Choosing_a_rabbit_veterinarian
https://wabbitwiki.com/wiki/Nevada
https://rabbit.org/care/rabbit-vets-near-me/
Along with the links I posted previously on megacolon, here are a few more, the first ones from well known and reliable rabbit organizations.
(LINKS MAY CONTAIN GRAPHIC MEDICAL RELATED PHOTOS)
https://houserabbit.org/rabbits101/health/illnesses-and-diseases/megacolon-syndrome/
https://rabbitwelfare.co.uk/wp-content/uploads/2023/05/RO-Spring-17-Megacolon.pdf
https://rabbitwelfare.co.uk/wp-content/uploads/2023/11/RO-Autumn-23-Megacolon.pdf
https://vgr1.com/megacolon/
https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0093750
With the GI stasis happening so long ago, I don't think it's likely to be related. But your rabbit getting diarrhea, that could have sparked this long term condition. True diarrhea in rabbits is usually caused by pathogenic bacteria. The bacteria can release toxins that essentially permanently damage the digestive tract, if it's not just outright fatal which is most often the outcome. So pretty incredible your rabbit survived if this is what happened.
Because the diarrhea was at the start of this, I'd be inclined to think this was the cause of your rabbits current GI issues. That your rabbit didn't start out with megacolon, but started out getting diarrhea somehow and developed permanent digestive damage resulting in ongoing megacolon type symptoms. If this is what's going on, usually changes to the diet can sometimes help improve poop quality, digestive function, and nutrient absorption. At least it did for 2 of my megacolon buns.
The fur loss could be a separate issue, like fur mites, which cause fur loss and dandruffy skin. Or maybe the skin is fine, and your rabbit either has rubbed the fur off somehow, is starting a heavy molt, or possibly his sister overgroomed him there. Or it could be related to poor nutrient absorption and nutrient deficiency.
So presuming this is acquired megacolon that your rabbit has, diet and sometimes meds, is usually how it's managed. There's not one specific diet though, as it can vary depending on how an individual rabbit is affected. If you look at the vgr1 article, it goes into detail about some of this.
For my rabbits, they were the most sensitive to any high sugar/carb food. Grains, fruit, sugars in meds, grains and sugars in pellets, all would cause their poop to get worse. It would usually cause their fecal poop to become more irregularly shaped and sticky with mucous, and digestive upset issues. So both rabbits were on a strict hay and select greens diet, and did really well on this diet, maintaining a healthy weight and active life.
My one rabbit that was born with this condition, he was also sensitive to the quality of hay he was fed. If the hay was too leafy of a cut, his fecal poop would get really moist and more log shaped. He had to have a medium coarse cut to maintain the best consistency in his fecal poop and best digestive motility. So he was always fed second cut timothy hay, that was a good mix of leaf (nutrients, protein) and stem (indigestible fiber).
These are all things I learned by trial and error. By seeing something wasn't working and trying something else. I had tried multiple brands and types of pellets, before determining that none could be tolerated. I always used a gradual approach, starting with very small amounts, and closely monitoring for any signs of digestive pain or upset. But what diet works best for your rabbit may be different than what worked for mine. Some rabbits do better on a higher protein more nutrient dense diet because of the poor absorption.
My suggestion would be to try and find a vet with knowledge about megacolon in rabbits, and preferably some experience treating it. Or even a vet that at least has knowledge that it is a real disease for rabbits would be a step up. When you call, specify you're looking for a rabbit vet knowledgeable about megacolon in rabbits, not cats. Diet is likely going to be your primary way of dealing with this, but having a knowledgeable rabbit vet working with you, they may know of some beneficial medications that might also help.
I don't know if a no pellet diet is appropriate for your rabbit or not, but if you feel your rabbit does need to stay on pellets, it might be worth trying a no grain pellet. Selective Naturals has one, Sherwood has one, there may be others. Any high quality pellet with no added grains, fruit, sugars, molasses, etc. Then a gradual transition so you can monitor for digestive upset, weight loss, or any other negative effects. If you find a pellet that your rabbit does really well on, it may be worth trying to gradually increase pellet amounts to help your rabbit get some weight back on. But monitor for increasing pellets causing a worsening of symptoms as well.
It might also be worth trying other brands of hay, in case there's something off with the hay you're currently using. Small pet select seems to have good hay, and there are other specialty companies that cater to providing high quality hay options for small pets. Maybe experiment trying different cuts and types. But I would suggest avoiding grain hays, due to the seeds carb content. Make sure whatever hay you use has absolutely no signs of mold (black or white spots, white dust, dampness, odd color, musty or sour smell), as that alone is toxic to rabbits.
You're looking for the right balance of what hay works best for firming up the fecal droppings, and balance of what hay and pellet combination provides sufficient nutrients for maintaining health and weight as much as possible. It's never going to be perfect. Your rabbit will always have the problem. But with the right diet for your individual rabbit, you can help minimize the negative affects of megacolon.
This is all just my opinion and a guess as to what might be going on based on the photos and description. I could be wrong and it could be something else. Liver problems can sometimes cause abnormal poop issues like this. So can heart issues and thymoma, which is why I was asking some of those other questions. So if your rabbit is having other abnormal symptoms not related to the digestive issues, like the unusual sneezing episodes and fur loss, it may be worth seeing that your vet looks into these other possibilities.
You are your rabbits advocate, and sometimes we have to be the ones making sure our pet is getting the correct and appropriate care. Not all vets are good vets, and there are much fewer good and knowledgeable rabbit vets available to us. A vet that says they treat rabbits, isn't necessarily a vet that is truly knowledgeable about rabbits. It took me a few tries going to several so called exotics vets, before I found one that really was knowledgeable. So if you feel you need to find a better vet, I suggest doing so. A really good rabbit vet can make all the difference in getting better care for your bun.
