DISCLAIMER: I'm not a vet and I have no veterinary or medical background whatsoever. This information on degenerative myelopathy in dogs is not meant as a substitute or replacement for veterinary advice. It's meant for educational and informational purposes only, as a starting point for discussing the diagnosis and treatment of degenerative myelopathy with a qualified vet.
Mobility is clearly one of those things that vastly contribute to quality of life. It's not as simple as being able to go for a walk; there are dogs that are content sniffing around the yard, or laying out in the sun, or playing games instead of going for a walk.
Mobility goes beyond just the ability to walk or play, though; during the later stages of degenerative myelopathy, dogs have a much harder time doing previously easy tasks. For example, he may want to go to the door to indicate he has to take a potty-break; but unable to get up, or get there in time, he might have an accident. This can be very distressing for some dogs. Other previously easy tasks that will become difficult include things like getting up from their beds ... changing positions when lying down... even getting a drink of water whenever they want one.
The disease of degenerative myelopathy in itself is painless. But pain can result from the dog taking compensatory actions to make up for his mobility challenges. For instance:
Dogs with DM typically still have good appetites. Is your dog still eating and drinking well? Is he maintaining a good body weight? Is he interested in food and enjoys eating? Is he staying adequately hydrated?
Other issues, such as pain (see above) or unrelated medical conditions may cause a dog to lose his appetite.
Is your dog still sleeping comfortably and well? It can be hard for dogs with degenerative myelopathy to change positions in order to get comfortable. They do need to change positions regularly in order to avoid pressure sores.
Does your dog still show interest in his favourite activites, and is he capable of doing them? He doesn't necessarily have to be capable of doing them the same way he previously did, in order to be happy. For example, dogs who used to love to take long, meandering walks may still be content to go on shorter walks, provided there are interesting things for him to sniff or friends to socialize with.
It's one thing to make the decision to euthanize when your pet seems tired or feels sick. Then, you know that the time is close and the decision is clearer. With degenerative myelopathy, dogs are usually mentally engaged with their families and with life; this can make it feel that much harder to make the decision to let him go.
You know your dog best. During highly-emotional times, it may be helpful to ask for an opinion from a third-party such as a trusted veterinarian who knows your dog.
The decision of when to euthanize is a highly personal and individual choice. I know that it's often helped me to hear other people's perspectives, so I hope that reading mine may be helpful in some way. I have always felt it best to let my pets go a little early, rather than even a day too late. I don't want to have to say goodbye during a crisis when they're feeling pain or fear or confusion. I don't want them to end their lives struggling with an injury or trying to recover from one. I want my pets to go feeling loved, safe, and happy.
My opinion is that you need to feel physically, mentally, and emotionally well to be able to best care for your dog. Being overwhelmed doesn't help anyone. Your dog doesn't want to feel like he is a burden. Love him well, give him an awesome last day, last week, or last month... and then let him go peacefully, with dignity.
Degenerative myelopathy is a difficult disease. It's hard on the dog, and hard on the people who love him so much. And yet, even had I known back then everything that I now know about the disease ... even had I known back then that my dog already had the disease ... I would have still adopted him. His amazing attitude, cheerfulness, acceptance, and grace of spirit was a bright light for me, even during the most difficult of times. It still is.
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