Georgia are doing the study on griffons not because it is particularly common in the breed (this isn't really known, although it certainly isn;t anywhere near as common a problem as in cavaliers) but because breeders became aware that it was an increasing problem in the breed and rallied to raise money for a study. Brussels griffons, unlike cavaliers, have many lines of dogs with no malformation -- this became clear from a range of international breeders who started scanning. Griffons are actually for this reason, the control group for the cavalier genome study because sadly, researchers could not find enough cavaliers without the malformation to serve as a control.
For any dog, the correct place to start is your own vet, making sure they are aware of the problem with SM in the breed -- eg that it is a known issue. I am sure the vet could contact LIVS for further information as well. That bunny hop would be the main issue of concern as it is so often distinctive for SM especially if coupled with scratching. I checked with one of the SM researchers, who believes you should have this investigated. However you don't want to make any assumptions but thoroughly check out all possibilities.
Cavaliers: Jaspar Lily Tansy Libby Mindy
In memory: Lucy Leo
Cavalier SM Information site:www.smcavaliers.com