Hi, I can help you with your question today.
It sounds like Snoopy has IVDD (intervertebral disk disease).
This is caused by movement of the intervertebral disk up into the spinal canal, where it puts pressure on the spinal cord.
The mildest sign we might see from this is pain.
If the swelling becomes greater and pressure on the spinal cord increases, we will next see loss of "conscious proprioception".
This is his awareness of where his feet are in space. If he loses CPs, he may stand with his toes curled under, he may stumble or appear drunk when he is walking.
If the pressure continues to increase, he can become paralyzed, and finally he can lose deep pain perception.
If this happens, he would need surgery on his neck. Even with surgery, we cannot guarantee recovery.
It sounds like he is progressing along this pathway - so we need to stop it!
The painkillers are a good start.
Other things we can do include muscle relaxants, injections of Adequan (at your vet), and additional pain medications (tramadol, gabapentin).
Aside from these, the MOST IMPORTANT thing is to keep his activity restricted.
He may not go on the stairs, he may not jump on or off of anything.
Block off the stairs and block off the furniture.
If you must, he can be kept immobile in a crate.
This should be done for a full 6-8 weeks.
He should only go outside (using a harness, no neck leads) for a short period to urinate and defecate. Then right back inside.
It will be a tough 2 months for you both, but the alternative could be permanent paralysis.
If you have more questions or if I can help in any other way, please do not hesitate to ask. I will be happy to continue further and do everything I can to provide you with the service you seek.