Coonhound Paralysis (also called acute idiopathic polyradiculoneuritis) is one of those neuropathies (neurological pathologies) of undetermined origin. It is an auto immune reaction, an immune mediated inflammation of nerves and nerve roots. It occurs when a dog previously sensitized ("allergic") to certain antigens, most commonly a protein in raccoon saliva, develops an immune reaction to the antigen. It seems to follow having been bitten by a raccoon, and seems to affect only dogs. It does NOT affect ALL dogs thus savaged by raccoons, nor does it seem to affect cats or raccoons similarly afflicted.
The scenario goes as follows. A few days after having been bitten, the dog begins to be weak on the hind end and gradually becomes more and more paralyzed, eventually losing control of bladder, and in some cases, of breathing. Fatalities are rare, but known. Severe cases can result in death from respiratory paralysis. This immune system reaction attacks portions of the peripheral nerves, causing rapidly progressing flaccid paralysis. If you can give supportive care for long enough, the dog gets better, usually within 4-6 weeks. There is no recommended "treatment" (antibiotic therapy) that works. Coonhound paralysis resembles tick paralysis. Affected dogs are at increased risk of future attacks if exposed again to raccoon saliva, since they are not sensitized to the antigen.
No toxins have ever been isolated from raccoon saliva, nor have micro-organisms been found that would account for it. It is generally considered to be an immune reaction to some protein in the saliva, which attacks the dog's own neural tissue.
The worst part is that raccoons are well know to carry and suffer from rabies. The symptoms of rabies are sometimes similar and incubation of rabies can be extremely short. How to differentiated between the two? A paired serum samples showing a steeply rising titre against rabies would be sufficient.
This disease is almost identical to Guillain Barre (aka John Barry) syndrome in humans.
Source: Hugh Baker, DVM (Ontario, Canada); Tracy Hammer, DVM (College of Vet Medicine MSU); W.B. Thomas, DVM (Neurologist, University of Tennessee)
Submitted by: Liz McKinney & Lynn Grimsley, Falling Branch Jack Russell Terrier, Virginia