To give those of you unfamiliar with it a short primer on lethal white, aka OLWS - it's kind of like HYPP. It's caused by a mutated gene and as long as you don't breed a positive to a positive, you CAN NOT get a lethal white foal. But in this case, a positive has one copy of the gene - not two. If they have two, they're dead within about 72 hours and you don't have to worry about them reproducing. They are both with malformed bowels and cannot defecate normally. It's like being born with a built-in impaction. The intestines are never going to work normally, so it's not a matter of the vet being able to clear the impaction. They just don't have the ability to get waste out of their body.
As with HYPP, you cannot tell by looking. If you breed two horses together that are positive, 25% of the time you're going to get a lethal white foal that has two copies of the gene and will die.
As with HYPP, there are a lot of misconceptions. People think you can only get a lethal white breeding two overos. BZZZZT! Wrong. You can get a lethal white breeding two SOLIDS. The gene has also been seen in tobianos. It happens, and the only way to know the truth is to test.
It costs a whopping $25 to test, so why wouldn't you test your horses if you breed spotted horses (it doesn't just happen in Paints but in Minis and other breeds where you have overo coat patterns), rather than risk a foal that dies in agony within his first few days of life? Oh wait, the same reason people don't HERDA test...because they are lazy, cheap and ignorant.
So, Backyard Breeder du Jour posts pics of her foal the other day and the educated folks on Horsetopia (they do exist) pointed out that it sure looked like a lethal white. But no, it's "very healthy." Uh-huh. Ooops! Spoke too soon! A day later, it's not doing well - but it's not a lethal white. No sirree. "The vet has been out and says he's not acting like a lethal white would and he does have a bit more color than just his tail. He's acting more like kidney failure than a colic. He is nursing well and was very active until early this morning. At this point the vet is stumped. We have our fingers crossed." You guessed it, finger crossing, prayers and good wishes from the Internet did not save the foal. Shocker!NOW they are testing to see if he was a lethal white! NOW! You couldn't spend the $25 before you bred the mare? I'll bet your vet bill has been a lot more than $25. Just a guess.
Of course, BYB here does not seem like the sharpest tool in the shed based upon her other pics on her web site. Her kids don't look like they have much better chance than her foals. She brags about her brand new facility - ok, we get it, you're not broke, so start OLWS testing your horses and buy your kids some boots and helmets!
And she is a registered nurse. I don't get it. I swear, I do not get it at all. She surely can understand genetics. She surely can understand what happens when that horse's hoof hits her kid's toes or worse yet her little face. I do NOT get it.OK, back on topic...as with HYPP and HERDA, I strongly recommend patronizing stallions whose breeders have done all of the testing so that there are no surprises. Remember, one of the best things we can do to encourage responsible breeding is to vote with our wallets - even if you know your mare is negative and the stallion's status is irrelevant, look for a tested stallion. Some stallion owners of positive stallions do not breed positive mares, and that is another policy that should be strongly encouraged. As with HERDA, a positive status isn't a reason not to breed - it's just a sign that you must only breed to a horse with a negative status.
$25 of knowing the facts or a 25% chance of a foal that is going to die within days. Seems like a no-brainer to me -- too bad so many people with no brains are breeding horses!
