Unexplained Bloating in 1.5 year old Labradoodle

I'm hoping for another opinion on what may be going on with my 1.5 year old Labradoodle Wally.  I rescued him in March 2023 very underweight (BCS 3/9) because his previous owner, among other forms of abuse and neglect, stopped feeding him. He's had severe GI issues since July, and I'm hoping that a vet can shed light on what our next steps should be.  

• Early July 2023: Took Wally by car from USA to Canada (12 hrs each way) to visit family. While there, he did visit the beach and play in the ocean.
• ~2 weeks after returning from trip: Began bloating & poop quality worsened. He was eating Purina Pro Salmon and Rice, and a transition to Hill’s Sensitive Stomach did not improve matters.

DIAGNOSTIC PROCEDURES/TESTS: Between the end of July through mid-September, he had the following test:

• Abdominal X-Ray: Gas evenly throughout his intestines and empty stomach; No visible foreign material
• Fecal Test: Negative for ova & parasites, Giardia, Flea Tapeworm, Hookworm, Whipworm, & Roundworm
• Urine Test: No relevant findings
• Abdominal Ultrasound: No relevant findings (Incidental Finding – Missing R Kidney)
• Bloodwork (CBC, Chemistry, T4, UA, Texas GI Panel): No relevant findings
• ACTH Stimulation Test: Negative (First cortisol test was slightly low)
• GI Biopsies: Negative – No sign of IBD or other inflammatory process. Confirmed missing R kidney, but no other structural abnormalities. During this procedure, surgeon performed prophylactic gastropexy.

MEDICATIONS:

• Metoclopramide: No improvement
• Probiotics: OTC Purina Pro Fortiflora – No improvement; Rx Visibiome – Was more gassy/bloated on it, but then got even worse when we stopped giving it to him
• Infant Gas Drops (Simethicone): No drastic improvement
• Gas-X: Caused him to vomit
• Metronidazole: Drastically improved him bloating initially.  Third round of antibiotics, though, had much less of an effect.
• Cerenia: He’s had a very clustered days of vomiting where his vet has prescribed this.

FOOD: Started on Purina Pro Salmon and Rice. Transitioned to the following, in this order:

• Hill’s Sensitive Stomach: No improvement
• Boiled Chicken and Rice: No improvement
• Hill’s Rx Diet z/d: Minor improvement over 3 months
• Purina Pro Rx EN Low-Fat (Current Diet): Worsening symptoms over 2 weeks (Could just be part of the transition?)

  Wally’s bloating waxes and wanes, though it’s typically worse in the evenings. He hasn’t had an “ideal” poop in months, but the quality of his bowel movements correlates to his bloating; when his bloating is worse, his poops are more liquidy/mucusy/occasionally have a jelly-like, pink substance in them. We’ve been working with our primary care, internal medicine, and veterinary nutritionist but I feel like we haven’t made much progress toward a diagnosis. Is there something in Canada that he could’ve been exposed to that USA vets wouldn’t be aware of?  Is there a more advanced fecal panel that we can try?  Any suggestions would be much appreciated, as its clear that Wally is very uncomfortable and we want to do whatever we can to help him. Thank you in advance!

Hello - first of all, thank you for that fabulous history, which was clear and well explained.  It can be frustrating when a lot of tests are carried out and come back negative; it would be the most satisfying thing in the world if I could say 'Oh, just give him compound X' and have compound X (or acupuncture, or snake oil) work miracles, but of course, as you know, the case is unlikely to be solved like this.  You have vets with a specialist knowledge of the area scrutinising your dog, far surpassing my own knowledge, so my only advice would be to go back to them, perhaps with this very well forumlated list and try questions like:  'Why do you think we haven't managed to find a way to keep my dog comfortable yet?'  'What haven't we managed to rule out?'  'What do you think is likely to be going on?'  'If this was your dog, what would you do next?'  'Is there anyone with a different approach to this sort of disease who might be able to help?'  and taking it from there.   I know that you've probably heard this many times, but compliance is vital e.g. the patient not being fed behind your back by helpful neighbours / well-meaning visitors etc, so it's well worth trying to rule this out yourself as far as you can if you haven't already.  It would also be good to know whether pancreatitis, hypothyroidism, lymphoma etc have been fully ruled out by those biopsies. For how long and how exclusively were the special diets fed?  Many vets reccommend up to six weeks on one food with no mouthfuls of anything else, which can be a tall order.  'Have we ruled everything out now?'  'What is most likely to be causing this in your opinion?'  'Have you had cases that haven't responded to all of these things before?'  'Could accupuncutre be helpful in these cases' may be a good question.  I mention acupucture because while many 'old wives tales' are told about it making it easy to dismiss, it does have an evidence-base in the literature for certain inflammatory conditions and gut motility disorders may be amongst them.  The ABVA (Association British Veterinary Acupuncture) who are keen on scientific, evidence-based research and produce papers, might be able to advise your vet about this.  More established medicines may have a firmer evidence base behind them and we would expect your specialists to have looked at all of this.  Wishing you the best of luck in getting to the bottom of this interesting case - please will you let us know if it is solved?

Thank you for your thorough response as well, I really do appreciate it.  He was on the hydrolyzed diet for 12 weeks, and we were extremely strict with it; I myself am a registered dietitian, so I have experience with human food trials and understand how one small bite of something else can skew the trial. I will bring this compiled list back to my vet and let you know if/when we figure it out! Thank you again.

Hi @Largelypeach, I seriously appreciate your concern.  We brought our dog to the emergency vet twice in the first week or so of his bloating, and both times they examined him, took X-rays/ultrasounds, and sent us home with a treatment plan.  He has since gotten a preventative gastropexy to prevent any emergencies as well.

Hi everyone - reporting back because I hope that this can help other pets/pet owners who feel like they've tried everything.  My dog's internal medicine vet reached out to international contacts to see if they had any insight, and the two agreed that my dog was dealing with a pretty gnarly case of dysbiosis. Before moving forward with a fecal transplant, she suggested we try the Hill's Science Diet GI Biome Food (https://www.chewy.com/hills-prescription-diet/dp/277111).  Within hours, my dog's condition changed for the better.  He is now pooping regularly, bloating far less, and overall seems much more happy/comfortable - he is a new dog!   This food has truly, whole-heartedly been a game-changer for him and, like I mentioned, I hope that this info can help other dogs with GI issues.