My 11 year old dog has Stage B2 DMVD, moderate left-sided enlargement, and he's on Pimobendan. His anxiety and resource guarding have been getting somewhat worse over the past year so his vet started him on Fluoxetine 10mg (he's ~11 kg) daily about 5 weeks ago. We already use Gabapentin for vet and grooming visits, but the Fluoxetine was started for his day-to-day anxiety and escalating resource guarding at home.
I came across this study that found blocking the serotonin transporter (which is what fluoxetine does) accelerated mitral valve degeneration in mice that already had valve disease. I'm going to bring this up with his cardiologist but wanted to get some other perspectives as well.
If the medication does accelerate his heart disease, then I feel like I'm in a catch-22. His anxiety is bad for his heart, but the medication to treat it might also be bad for his heart, so I'm not sure which one is the bigger risk or if the anxiety medication is even worth it.
The anxiety is at its worst during vet and grooming visits. Since starting the fluoxetine, he noticeably does seem calmer and less reactive overall, at home and during walks, so it does seem to be working. If there's an alternative medication that could achieve the same results without the negative effects on his heart (or any other side effects that could be harmful), that would obviously be better.
My questions:
- Do you think this is a real clinical risk at standard doses, or more of a lab finding?
- Have you ever had concerns about prescribing SSRIs to a dog with valve disease, or is this a non-issue in practice?
- Are there alternative anxiety medications for dogs with DMVD that don't work through serotonin?
- Is the concern in the catch-22 paragraph above valid, or am I overthinking it? I just want to make sure I do what's best for him.
Thank you in advance for any input.