If your dog is showing symptoms of paralysis, or earlier signs like paresis or incoordination, get them to their veterinarian ASAP!
Do not be tempted to ‘wait and see’ what happens in these cases. These conditions tend to be time sensitive and the earlier you can intervene, the more likely your dog will have a good outcome. Getting a referral to a veterinary neurologist, where possible, is often indicated.
While serious, the good news is that many causes of paralysis are treatable. Full return to function (and fetching!) is absolutely possible.
Pro Tip: Contact your vet asap if you start noticing signs of paralysis, as it is likely to worsen and unlikely to resolve on its own.