Did my vet miss something?

My 8 year old chihuahua passed away on Friday and the vet said the cause of death is unknown. To give a bit of background, she went for her routine vaccines in March and we were told she had developed a moderate heart murmur and to monitor her. Early May I started to notice she was become more tired on walks and panting excessively even at rest so I took her back to the vet and asked if this could be related to her heart but I was told no it was more likely pain. The vet thought back and joint pain and prescribed Gabapentin. After 2 weeks she seems a bit better but still panting. Once the medication stopped she went back downhill again so we took her to the vet again and was told again it was pain related and to keep her on the Gabapentin for 3 months. However this time she stopped eating and it was very difficult to get her to take the medication. We tied hiding it in food, tried dissolving in water etc. Then she developed a swollen/distended belly despite not eating. She also had diarrhoea over a few times and was sick once. She was drinking more than usual but still hasn’t really eaten for around 5 days. Only small amounts of chicken. As she wasn't improving we took her back to the vet again and was told to keep going with the medication (we were then given liquid Gabapentin to try) and she was given an anti nausea injection and told to return after the weekend if she hadn’t improved. The following morning I gave her the liquid Gabapentin and left for work. My husband came home at lunch and said she was off and panting heavily. She then collapsed and had foam coming foam her nose and died very shortly after on the way to the vet. We both feel something was missed over the month period we had been taking her to the vet. Ultimately the vet said cause of death is unknown and they would just be speculating but feel she may have aspirated on some vomit? Reading up on her symptoms it points to heart failure possibly but how could this have been missed? We were told each time her heart was stable. Could it have been anything else? Did we do something wrong? I’m absolutely racked with guilt.

Hello!  I'm so sorry to hear that you have lost your loved one; you must be devastated and I wonder whether you are also at that stage of greif known as 'bargaining,' where people search for reasons that the death shouldn't have happened. If so, that is a normal part of processing greif and asking questions is certainly a useful way to address it. You are correct in that breathlessness can be a sign of heart failure as well as pain, and that heart failure can occur in conjunction with a murmur.  I am also convinced that your vet would have known this, so I wonder - having already diagnosed the murmur - that they didn't attribute the signs they observed to heart disesase, but to pain.  You don't say why this was, but I would expect them to be able to tell you.  Perhaps the clinical signs or physical presentation aligned better with pancreatitis or cancer;  perhaps that distended abdomen seemed likely to hide a tumour or pancreatitis or kidney or liver disease or even an exceptionally-timed womb infection or pregnancy, any of which might have been implicated in an early death.  The way to have known would have been to carry out diagnostic tests; perhaps abdominal scans, radiographs and / or heart scans.  If there were to have been fluid on the abdomen, they might also have been able to tap a little and find more out about it.  

It still may not be too late to put these questions to your vet; could a post mortem be a possibility?  If not, can they talk to you about the decisions that they made at each point, in order to help you to understand?  I agree that in the event of the heart condition being stable, there are certainly other possible causes - and of course, that one condition could have put pressure on another.   The RALPH site was set up to help greiving pet oweners - although Ralph was the vet concerned's cat, I beleive that they help dog owners too.  It may be useful to reach out to them.  Above all, I hope that something can help you to find peace after this sad event.  Wishing you all the best from here.

Thanks, we weren’t offered any sort of diagnostic tests or any sort of port mortem. When we were told about the heart murmur in March it was said she could be referred to a specialist further down the line if her heart murmur became worse or she showed any their symptoms. However each time we took her recently they said her heart was stable and no major changes had occurred. I spoke with the vet yesterday who again said she thought it likely but not for sure she had aspirated on some vomit hence the foaming from the nose. And that when she had listened to her stomach the previous day it sounded more gassy than fluid filled. They said they all fully expected her to improve. In terms of infection, she had been brewing any sort of temperature (confirmed by the vet) so they ruled out infection. I worry it was me giving her the liquid Gabapentin with had caused the sudden change. Did this go into her lung? Was the dose not prescribed properly? I’ve read about xylitol poisoning too in relation to liquid Gabapentin. I know none of this will bring her back and actually I don’t know if I’m making myself worse looking for answers I may never get but it was just so sudden.