The problem is that all the names are either inaccurate or offending. For instance, the Dexter breed as a whole is rather short legged, and even animals dubbed long legged are often short legged when compared to members of other breeds. Another problem is that there are a lot of rather large dwarfs, and a lot of rather small Normals. The difference is mostly in the length of the cannon bone, and a shortened cannon bone produces the classic choppy gait of the Dwarf/Short leg. I have tried to get a Type A and Type B to catch on, but so far to no avail. In the absence of that, I believe the Short Leg and Proportionate are probably the most descriptive.
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There is now a genetic test available for breeders who are unable to tell what type they have, for animals that are borderline in type, or for people who just want to make sure. However, test or no test, the bottom line is that some people are attracted to the choppy gait and compressed shape of the short legged type and will always be devoted to this model. The problem is that many new breeders are not aware of the genotype of these animals and do not know that certain precautions can be taken in order to avoid having bulldog calves.
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Short Legged/Dwarf Dexters are heterozygous for a trait known as chondrodysplasia or achondroplasia. This means that they have one "Dwarf" gene and one "Normal" gene. Animals with two Dwarf genes (homozygous dominant) are called Bulldog calves. They are usually spontaneously aborted and never survive. The only way you can get a Bulldog calf is by breeding two Short legged/dwarf animals together. Bulldogs can be avoided by only breeding Dwarfs to Normals, or only breeding Normal to Normal.
These are the
expected ratios you would get when breeding the following combinations. I
am using the terms Dwarf and Normal, since those are generally the terms used by
geneticists.
Dwarf X Normal = 50% Dwarf calves, 50% Normal calves
Normal X Normal = 100% Normal calves
Dwarf X Dwarf = 50% Dwarf calves, 25% Normal calves, 25% Bulldog calves
Bulldog X Bulldog (if it were possible) = 100% Bulldogs
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As you can see, Dwarf animals do not produce consistent results, since they are genetically 1/2 Bulldog. If the Bulldog calves were able to grow up and reproduce, they would "breed true" since they do not carry any Normal genes. Also, breeding Dwarf to Normal gives you the same number of Dwarf calves as breeding Dwarf to Dwarf. And, breeding Dwarf to Normal eliminates the risk of Bulldog calves and replaces this loss with Normal calves. Of course, if you only breed Normal to Normal, you don't have to worry about any of this.
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