I have a line issue and would like some input.
This is not bashing any dog so no names will be mentioned.

I will try to make it understandable.......


I have been breeding for 25 years, on a 6th generation of my maternal line.
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Bitch A ( 4 yrs)- dam is out of my lines, SIRE is CH and an outcross from the dam's linebreeding

Bitch B (5 yrs) - dam is similar to above dam but only by lines, out of same outcross sire.

half sisters by the outcross sire
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Bitch B was bred 2 years ago to my current stud, he is similar lines but loose linebreeding
......all pups were in excellent health


Bitch B was bred last year to OUTSIDE stud with similar lines to my lines, a loose linebreeding.
....out of 9 pups , 4 had overbites.


Current litters:

Bitch A bred to my current stud (extremely nice looking pups) but
.......3 of 4 pups have overbites

Bitch B bred to my current stud (extremely nice looking pups) but
.......4 of 7 pups have overbites


My stud has been use often in my kennel and to outside bitches enough for me to know he does not have this issue.

My question is....

is this gene coming from the outcross sire of these two girls?

should I go back to a tighter linebreeding to the bitches maternal side to dilute the possibility?

could it be environmental or food (lack of essentials)?

I have found that bites will skip a generation, I bred a lovely bitch to a a dog with normal bite from one of the strongest bitch lines in the country, his sire was known for producing bad bites, in 30 yrs never had a bad one. Got parrot mouths.
Bred adult bitch from that litter w/parrot mouths now 3 times, not one bad bite in any litter, and she was very tightly linebred on the bitch side. Does this help?

It is my understanding ( from a vet ), that bite problems are recessive....meaning both parents carry the gene.

In my experience, overshot bite problems come from both parents - you were just lucky the first time you bred to your stud dog with Bitch B and didn't get overbites. It is apparently in your lines, so be careful and ask questions before you breed.

my line did not have issue up until these two girls.
so this is why I am believe it was brought in by their sire.

I understand it takes two genes....I understand they now carry the gene....this is why I am now asking about what you would do for the next step?

would you go back heavier into your out foundation line that you know does NOT have it or would you out cross again?

Neither one of these girls will go back to my stud. He must have one of the pair but has never produced it. I did not breed him but have owned him most his life, he comes from a well known kennel.

again I am not blaming, bashing or looking for excuses...just suggestions.

But your stud dog is the one producing the overbites when bred to them, so yes, it might have come from the outside stud, but your boy has it too. You can try going back to your foundation - but it might be there too, just has never shown up before now. Whatever you do, ask about bites before choosing a stud dog. And however annoying an overbite is, just keep in mind it won't affect the ability of the dog to be a good pet, which some other defect might.