According to ACVO's publication Ocular disorders presumed to be inherited in dogs (1999), cherry eye (prolapsed gland of the third eyelid) has been identified as a known or suspected inherited disorder in the following breeds: Beagle, Bloodhound, Bulldog (English), Chinese shar pei, Cocker spaniel, Lhasa apso, Newfoundland. ACVO's breeding advice regarding cherry eye is that it's "breeder option", meaning that the entity is suspected of being inherited but does not represent potential compromise of vision or other ocular function.
Edited to add the prevalence of cherry eye reported in BHCA's 1998 Health Survey was approximately 5%.
If a dog is a carrier or affected with either VWD or thrombopathia, there is a high likelihood that it will also have cherry eye. I had 3 affected dogs years ago and all of them had it in both eyes. I've never had it with an animal that has been tested and found to be normal.
Hmmm, I've only had one pup tested for thrombopathia (passed with flying colors), but since when we do heartworm testing we sometimes have problems with the blood clotting too fast I don't think either of those are a problem here.
Still sounds like a phlebotomy problem. My interest was piqued enough to see whether hypercoagulable states had been described in dogs. The only info I could find was on hypercoagulable states as secondary problems in IMHA (immune mediated hemolytic anemia) and Cushings, and DIC (disseminated intravascular coagulopathy), which complicates several disorders. In humans there are also primary hypercoagulable disorders that contribute to infertility/pregnancy loss, clot formation after periods of inactivity, and skin disorders.