Selecting Breeding Stock

[Saffioraire]

An offshoot thread from another question I've asked....

I suppose my question would be how far to people go in breeding selection criteria? Of course there are dogs who are better than others, and some carry or are affected by particular ailments etc... but how far do you go in terms of the possible genetic issues that may or may not be in a line because "once there was a few pups affected by a different ailment that is linked to a more severe one" or "the sire has never produced the ailment but the litter sister has".... etc, etc. I'm not talking about detectable ailments here like HD/ED/Eyes/Ears, I mean ones you can't test for and there is no known mode of genetic inheritance nor how clearly genetics is linked and could possible be brought about mostly by environment. There is always the chance you will have a recessive gene or a mutant gene etc... so where do people draw the line between a calculated risk and throwing the baby out with the bathwater?

(Just trying to get a feel for how other breeders draw together their acceptable breeding stock and why)

[Christina]

Very difficult question. You are relying on breeder honesty & knowledge of their lines when you ask the question. In my breed the concerns I have are luxating patella & epilepsy, the 2 common things that can't be tested for.

All you can do is computer check as many in the lines as you can then breed your first litter ( may be productive or not ) & all being well always check back on them when they are adults, over a year.

I do a courtesy call & ask if I am not still in contact with an owner or the litter mates & just say it is part of my breeding strategy to check all is well.

Fortunately my breed only have small litters & many owners stay in contact if only at xmas.

I guess the answer to what do you do is that if a problem occurs you have to decide if you feel it is a one off.Depends what problem crops up.

If so & you breed another litter & it happens again you must desex.

[espinay2]

This article may help.

'Prioritising Genetic Defects' by George Padgett: http://www.lgd.org/library/PadgettDefects.htm

[dancinbcs]

Breeders need to all acknowledge that all dogs carry defects and be 100% honest with anyone wanting to breed to their lines. Possible links to all known problems in the breed need to be discussed and the risks weighed up because there is no such thing as a risk free mating. The main point should be to not double up on the same problem.

"Popular Sire Syndrome" or popular dam for that matter, is a real problem even if they don't produce that many actual offspring themselves. The problems arise when progeny and grandprogeny become extensively used and within 10-15 years you find the original dog or bitch is on every pedigree in the breed at around the same time you trace a defective gene back to them.

The health problems that are of the least worry are those you can test for and that is why I am always trying to explain to breeders that the whole point of having a DNA test for an autosomal recessive condition, is so that you don't need to eliminate carriers of that condition from the gene pool. Once you have a test the condition is no longer a problem, as it can so easily be controlled. Far better to worry about not doubling up on condtions that there are no tests for.

Once you discover about 6 related cases of any defect, that is the time to rally the other breeders, find a geneticist to develop a test and start raising lots of money to get it to happen. Of course some conditions are easier to find tests for than others but open discussion between breeders is the only way to track the more complex ones and try to put the pieces of the puzzle together.