Question ~ If you have a stallion or mare that produces a minimal dwarf are they likely to produce the typical dwarf with the bad bite, large head and crooked legs?
Where can we find more information on the "types" of dwarf genes?
To try to bring some rational understanding to this subject about "minimal dwarfs", I feel I need to comment about the term, what it means and its use.
First of all, the term "minimal dwarf" is totally a made up term by someone somewhere that wanted to say that a horse that wasnt a dwarf but looked like one was a "minimal dwarf", or wanted to say that a true dwarf that was minimally affected (ie a good dwarf) was a "minimal dwarf". So needless to say, the term has been widely used for a wide variety of "good dwarfs" or "horses with really bad conformation" or "a horse that had an extremely exotic head, bad legs, and really small in height". Any way you look at it, the term has been used to try to describe a wide variety of horses with "some sort of problem." So with that said, I strongly feel the term is incorrect and it is used improperly to describe certain horses.
If you have a dwarf that is "a good dwarf" in the sense that it has the disease but it is not as severe in showing its characterisitcs, then you have a dwarf with two homozygous recessive genes showing less gene expression than might be typically seen. Your dwarf is no less of a dwarf than someone else's dwarf that might be more severely affected by it's genes' expression of the disease.
Unless you are looking at two different types of dwarfism, then you cant compare at all, because the pathology of the two diseases are different.
If you have a very small horse with an exotic head, bad legs, and maybe other conformational faults, how can you say the horse is a minimal dwarf?? Dont you think it is possible to have all of those characterisitics and NOT be a dwarf, (especially in this breed). That is not to say the horse is not possibly a carrier. If that IS the case, which you dont know until it produces one, then you have a carrier that is having expressivity of a recessive gene competing with the dominant gene. BUT, the horse is NOT a dwarf in having the characterisitics of the disease. I have personally seen "really good dwarfs" and horses with expressivity of a recessive dwarf gene look very similar. So until there is some real information to catagorize these horses with certain traits and variances, I recommend to everyone not to use the term so loosely.
So to answer your question in a lengthy way, I do not know if the "minimal dwarf" a stallion and a mare have is actually a minimal dwarf and not a really bad horse, I dont have pics to see. I have seen thousands of pics of various horses over the years. I have learned to "see" certain characterisitics of horses that might be expressivity of a recessive dwarf gene. But that does not mean the horse is a "minimal dwarf", it is no such thing. A horse with small size and an underbite does NOT classify the horse as a "minimal dwarf". An underbite is a deleterious trait all its own, without dwarfism causing it. Crooked legs on a small horse does not mean it is a minimal dwarf, crooked legs are in every horse breed. Our breed sees more of them because the size of the horse is not 1500 lbs. A large horse foal or yearling with severely crooked legs gets put down, we seem to let it go try to "fix it" and keep those alive, not because it is trying to be caring or that we try to breed for it. But, because of their small size they CAN still walk, run and breed, we keep perpetuating certain deleterious characterisitics that are getting confused with dwarfism.
So I cannot tell you anything about if a stallion or mare that produces what might or might not be a dwarf, that actually later produce a dwarf. They probably have a possibility. I do not know the quality of the stallion or mare, I do not know the characterisitcs of the "minimal dwarf". So when you give me very limited information I have to qualify my answer. I wish I could be more clear and not than this vague but I cant.
I cant really give much information over the internet about my work or the types with pictures or possible candidate gene homologies, with all that I have done, and the limited amount of work one person can get done in a lab at any given time, a large biotech lab could easily get the info and dedicate an entire group to it and scoop all my work, get the answers and get it out, and all my work since 1993 is gone, and I dont have a thesis to defend. I present my work to certain groups with enough information to grasp the enormity of my undertaking and try to help them understand what we as breeders can do now to try and breed better horses until some answers are known.
John
