It makes for an interesting general question: Does warping breed true. The realm of Power magic addresses the way a mage can force warping on an animal to mutate it but does its kids have the same mutation?
Real world answer is that it might.
In paradigm answer is that it might but with more emphasis on "what you see is what you get".
Same answer as above.
Thats actually an interesting idea, and im surprised this is the first time anyone seems to think of it.
Could probably move through a generation in a week without any trouble at all(including surrounding work).
Ah but creoing an animal means you get ONE, creating a functioning breed means you can get as many as you want.
Well, since warping and twilight scars cannot be cured (for want of a better word) by Hermetic magic, it suggests that warping is a change to the essential nature (which can change - the essential nature of a child is not that of an aged, arthritic man). As such, I reckon it probably would breed true - I suspect that sayings like "Bad blood will out" or their equivalents are known in the thirteenth century.
That said, controlling said warping is a different matter. I'm not particularly fond of the systems for Fertility Magic presented in Ancient Magic, but the idea that you can (over generations, perhaps, or requiring breeding pairs, or both) shift and mold a species is definitely possible in canon and a wonderful target for original research.
I can think of several reasons why you might want to use breeding.
Intelligent animals make companions and servants, and might be more appropriate for certain unusual covenants
Animals which produce unusual or exotic animal products (milk which helps heal burns, or unusually fine leather, perfect for the most special of scrolls) would be a useful source of income
A lineage of horses unaffected by the gift would be very valuable, and the sale of their geldings to the Order would be a nice, reliable earner.
Enchanted items and rituals consume vis to repeat, but tamed, hounds only cost you food (and grogs to look after them, I suppose).
Because it's not only possible but likely that a member of House Bonisagus would ask himself the question, "Is it possible to breed two foot long dragons for more convenient familairs?"
Because it'd give bragging rights at the next Tribunal.