I am sorry to hear that your pet is at this point. I just put my beloved girl, Karlee, down this last year for the same exact reasons, so I will try to help you determine when enough is enough. As pet owners, you ultimately have to make the decision concerning your pet's healthcare issues, but hopefully, I can help in some small way to let you know how to proceed.
If your pet is truly nonambulatory and can NOT get up to walk, urinate, or defecate without risk of falling, stumbling, or being extremely painful, than this is a bad sign. Sling therapy and mobile wheel chair devices CAN be used if you are interested in pursuing additional avenues for your pet. It can be hard to give up on your pet when they are totally themselves mentally except for their bum back end!
Appetite is a great indicator of your pet's pain threshhold. Dogs that are miserable will not eat!! IF your pet is still enjoying food and treats, than the pain he is experiencing is still manageable!!
Based on your description, I have to wonder if your pet is on STEROIDS as an antiinflammatory medication. At high doses, steroids can cause bloody stools and diarrhea secondary to bacterial overgrowth. Steroids can be beneficial short term in dogs with sudden back blowouts, but LONGTERM, safer, equally effective therapeutic protocols should be used instead.
Before you throw in the towel, I would consider switching to an alternative therapy plan for your pet using a combination of NonSteroidal antiinflammatories( NSAIDS), Opiate pain medications, GI protectants, and muscle relaxants. In addition, the usage of joint supplements like Chondroitin Sulfate Glucosamine and the injectable joint protectant called Adequan once monthly can greatly help slow down the onslaught of degenerative arthritis effects!
A great example of a protocol I use in practice would be Rimadyl or Previcox ( NSAID) once daily with Tramadol or Codeine 2 X daily ( PAIN MED), plus or minus a muscle relaxant like Robaxin to help with muscle spasm and tenseness associated with pain. Pepcid would be given twice daily in addition to arthritis medications.
IF your pet is not on steroids, than he may just be sensitive to the NSAID that he is on, and you can ask your vet for an alternative.
My favorite NSAIDs include : Rimadyl, Previcox, Deramaxx, Etogesic and Zubrin.
Whenever steroids or NSAIDS are used an antacid like Pepcid should ALWAYS be given also!! If your pet is not currently on Zantac or Pepcid, than you should ask your vet to prescribe some for you immediately!
If bacterial overgrowth in the gut is contributing to the loose stools, than a short course of Metronidazole ( intestinal antibiotic) for 5-7 days coupled with 3 X daily yogurt or probiotic therapy can help reestablish normal GI flora and resolve loose, smelly stools.
When your pet develops inconsolable pain, a lack in interest in food, whines excessively or is depressed and also struggles with both urinary and fecal incontinence, than it may very well be time to consider euthanasia as the kindest, and most loving gesture towards your pet.
Having gone through it myself, it was NOT any easier being a vet!! Ultimately, you have to do what is only fair and right for your pet....not what feels right to you....
I hope I gave you something to think about. I would definitely talk to your vet about changing your current treatment protocol and treating the loose, bloody stools.
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Best Wishes to You and Your Pet!
Dr. Jodi L. Smith