nd often cavaliers are a bit babyish - drama queens
I have heard this from many vets too and heard it even before I decided to get a cavalier.
However: I have also now spoken to a wide range of neurologists who feel there is a very likely reason for this -- that many cavaliers who are 'drama queens' actually have the sensitivites and pain that come from the skull malformation that can result in SM, or have SM itself. If 90%-plus of ALL cavaliers have the skull malformation, that means probably most have some restriction in the flow of the fluid that baths the brain and flows around the spine. This alone can cause some cavaliers to be symptomatic with full SM symptoms, and that same restirction of flow can cause gradual syrinx formation. It would therefore make sense in a breed in which almost every dog has malformation of this sort and at least half of research samples have syrinxes, that this would cause extra sensitivity and pain -- ESPECIALLY from injections into the shoulder area. Talk to UK and Irish vets and they will say 'Oh, cavaliers always are big crybabies when they get their injections." More likely it is because a needle is being stuck into the single most sensitive area of their bodies.
If you have a dog that is uncomfortable being touched, especially in head, ears, neck, spine, or leg areas, yelps when injected, occasionally yelps when touched for no discernible reason, or sometimes cries in pain when lifted or being touched -- these actions have all been strongly correlated to the presence of the malformation and syrinxes. This is because the increased CSF pressure and/or syrinxes press against nerve endings and make the dog hypersensitive/painful in these specific areas. Syrinxes and increased pressure are focused in the lower neck upper spine area, and this is where the nerves are concentrated that involve sensations in the shoulder, head, neck and limbs.
Neurologists increasingly think cavaliers owners need to be very aware of these issues in this breed and not think that, because a cavalier does not have really obvious SM symptoms, it doesn't have any SM or CM (malformation) related pain. This doesn't mean a dog will develop fully symptomatic SM, but does mean to keep in mind that these dogs are burdened with this health issue in huge numbers and it is a likely reason for why some dogs are especially sensitive -- if a dog shows pain, then avoid the type of touch that produces it. And just keep an eye out for further development as if pain becomes more common and general, there are medications that can keep a dog very comfortable with this type of low level pain.