04 April 2013

A good day, plus some math and thoughts about breeding

First off, it was in the low 50's and sunny day (that's about 11C for my European friends). With the sun it was a beautiful day and we made the most of it with a long hike in the sunshine - we probably hiked about 7.5 miles (12km); we were out about 2 and 1/2 hours. Me, my 2 fitter dogs (Seri and Drifter are not up for that long of a hike, but I'm working on getting at least Seri up to it), and a friend and her dogs. It is a nice feeling to be tired at the end of a day, although I was pretty happy that neither myself, Kiba, or Strafe seemed to be dragging or slowing down in the least at the end of it. I actually had to keep calling Kiba back, she was excited to hike with friends since we usually go alone, and she was trying to go just a little too fast for the first hour or so!

Tomorrow we will take a slightly easier day, with several 15-20min walks in the field only. Saturday and Sunday Strafe and I are trialing in AKC, our first trial since AKC Nationals. Hopefully we can pick up a QQ or two and some points towards next year's event. I am probably also running my mother's 2 dogs since she managed to injure herself and wants to let it heal.

Here is a picture of my dog to break up this post!

by Great Dane Photos
My friend said that Kiba is always smiling when doing agility. A great incentive to attempt to continue running her!

And now a meandering blurb about breeding (well, about epilepsy in border collies, and how I view it): read only if you're interested!

 I now own a breedable, healthy, adult border collie. For years I have been researching and tracking health problems in the breed, and especially in related lines to my own dogs. My biggest concern when looking at the health and pedigree of a dog is epilepsy. Why? Well it should be obvious - a dog with epilepsy is severely affected in their quality of life. It is a horrible problem to have, and it is a problem in border collies. I find that many people simply don't want to talk about it, will "sweep it under the rug", or make excuses for it ("the dog probably hit his head"). But if there is no cause discovered, it is probably genetic. Epilepsy is not  simple, like coat color. It will not have a genetic test out anytime soon, in my opinion, because it is highly likely that it is a polygenic problem. Your dog won't simply "carry epilepsy" or be clear of it.

It is my belief that pretty much every BC has the ability to produce epilepsy if the "wrong" cross is made. So for a brief example, let's say it is polygenic, involving 3 genes, and you must have aaBbcc in order to have a dog who seize. If you breed 2 dogs who are both AabbCc, you cannot get the the B necessary to produce epilepsy. However, let us say you have a dog who is AaBbCc.... because of the A and C he himself may never have a seizure, however, if bred to an AabbCc dog, it becomes possible to produce the aaBbcc necessary to have epilepsy. It is not going to be every puppy... just looking at the B's alone - each pup has only a 50% chance of getting Bb... the others will have bb. Then adding in the A and C... each pup has only a 25% chance of inheriting the aa, and also 25% of the bb necessary in this example. Another 25% chance for AA, and 50% for Aa, neither of which will seize. The same with the B's! so when you add all this goopy mess together, it means (if I'm doing the math right, which I may not be!) that each puppy has only a 3% of developing epilepsy. Complicated, huh? Now imagine there are 4, or 5, or more genes involved!

This is how I look at epilepsy. Looking at it this way, I tend to look for lines where it seems that some common necessary element might be present (say, the "bb" in this example) meaning that epilepsy seems to be present more often than I would expect. I will say with fair certainty that epilepsy is in pretty much every line of border collies to some degree - it is a matter of finding a pedigree where no very close relatives have it, or it is very uncommon. I will NOT knowingly breed or get a puppy from a dog where I know the parent or immediate family member has a littermate affected, as I have seen a bit of a pattern (anecdotal!) in littermates producing it in the next generation. Half-siblings are a grey area, and that is where I start looking at frequency of the issue. If the dog has produced 186 puppies, and only 2 have epilepsy, I will consider breeding the half-sibling of the affected dogs if the one in question has a totally unrelated mother to the affected ones.

Frequency can be a problem as well though. Let's consider Stud Dog A for a moment. Let's say he was bred 10 times, and all fairly healthy pups, no epilepsy. OK, great! Now he is bred to 20 more bitches. Oh no, one of them threw a single pup with epilepsy. What do we do with Stud Dog A? If the owner had stopped breeding at 10 litters, this dog would never have been implicated as "carrier". How do we reconcile this?

There are no easy answers. Just wanted to share my views on a complex and frustrating topic! I have, so far, been very lucky to never have an affected dog, although 2 of my dogs have very close relatives who are affected.

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