Dyschondroplasia

Dyschondroplasia of genetic origin is seen in most breeds of cattle. The forms range from the so-called Dexter “bulldog” lethal, in which the calf is invariably stillborn, to those animals that are mildly affected.

The brachycephalic dwarfs that were common in Hereford cattle in the 1950s largely have been eliminated through genetic selection. Short faces, bulging foreheads, prognathism, large abdomens, and short legs are characteristic. They are approximately half normal size. The dolichocephalic dwarf, most commonly seen in Angus cattle, is of the same general body conformation as the brachycephalic dwarf, except that it has a long head and does not have either a bulging forehead or prognathism. The short-faced calves are frequently referred to as “snorter” dwarfs because of their labored and audible breathing. Both types are of low viability and susceptible to bloat. Their carcasses are undesirable, and they are rarely kept except for research purposes.

Dyschondroplasia of the appendicular and axial skeletons also is seen in dogs. The former is reported in Poodles and Scottish Terriers, the latter in Alaskan Malamutes, Basset Hounds, Dachshunds, Poodles, and Scottish Terriers. In some breeds (Bassets, Dachshunds, Pekingese), the appendicular dyschondroplastic characteristics are an important feature of breed type. In Malamutes, the condition is accompanied by anemia.