Although neck pain is a common telltale symptom of atlantoaxial instability, it's far from the only one. (dogcare.dailypuppy.com)
Other telltale symptoms include damp patches in bedding, damp hind legs and inordinate penis or vulva licking. (animals.mom.me)
Lyme Disease: unlike the famous «bull's eye» rash that people exposed to Lyme disease often spot, no such telltale symptom occurs in Cavalier King Charles Spaniels (dogs). (cruisincavaliers.com)