Lines with Seizures

[abcollie]

Then comes the problem of people not wanting to talk about it. How do you do research on "a line" if no one "admits" to it?

[Eileen Stein]

Unless it turns out that the epilepsy mutation(s) have some positive survival value (or unless onset was - at one time - late) its hard to believe humans allowed epileptic dogs to live and breed during the domestication period(s).

 

It's much easier to understand how, much later when breeds were being differentiated that human's ignored epilepsy for superior show ring success/birdiness/sheepdog outruns/etc.

 

Donald, my understanding is that it's likely epilepsy is so polygenic that many dogs who never display symptoms of epilepsy are contributing to their offspring many of the genes that play a role in producing epilepsy. To put it in drastically oversimplified terms, they themselves did not show symptoms of epilepsy because, while they carried genes A, B, C, and D, they did not carry genes E and F. But when bred to a seizure-free dog who carried genes D, E and F, but did not carry genes A, B and C, some of the pups hit the bad lottery and were epileptic.

 

So in addition to the cases where humans ignored symptomatic epilepsy to breed for show ring or other success (or simple profit), there are many other cases, at all periods of canine history, where epilepsy genes were transmitted because, due to the complexity of the genetics involved, the parents were not compromised by epilepsy, either in human eyes or in their ability to survive and acquire a mate.

[KnottyClarence]

Nobody breeds to get seizures. It's what the breeder does after finding seizures that matters.

[abcollie]

Donald, my understanding is that it's likely epilepsy is so polygenic that many dogs who never display symptoms of epilepsy are contributing to their offspring many of the genes that play a role in producing epilepsy. To put it in drastically oversimplified terms, they themselves did not show symptoms of epilepsy because, while they carried genes A, B, C, and D, they did not carry genes E and F. But when bred to a seizure-free dog who carried genes D, E and F, but did not carry genes A, B and C, some of the pups hit the bad lottery and were epileptic.

 

So in addition to the cases where humans ignored symptomatic epilepsy to breed for show ring or other success (or simple profit), there are many other cases, at all periods of canine history, where epilepsy genes were transmitted because, due to the complexity of the genetics involved, the parents were not compromised by epilepsy, either in human eyes or in their ability to survive and acquire a mate.

 

So are there more of them "today" because we are hitting the "unlucky lottery" or - admitting to it more - or the lines are getting closer or ??? Or just because there are a lot more Border Collies today than there use to be. 25 years ago I very seldom heard of a Border Collie with "issues".

[Alchemist]

So are there more of them "today" because we are hitting the "unlucky lottery" or - admitting to it more - or the lines are getting closer or ??? Or just because there are a lot more Border Collies today than there use to be. 25 years ago I very seldom heard of a Border Collie with "issues".

 

Don't know the answer to this question, but I had a Border collie who developed epilepsy at a relatively advanced age (15?) WAY back (in the mid-late 1980s?). That would be roughly 20-25 years ago.

 

Fortunately it wasn't serious and was controlled by meds.

 

Oh, and she was working-bred. Not sure that there was any other sort of Border collie way back then. Her father was a highly regarded top young working dog in S. Cal. at the time (I know, back then, big fish, small pond, right?) but her grandparents were all imported, and she had quite a few ISDS National and International champions among her grandparents/great-grandparents. Wish I could find her pedigree today... She was born in 1975. She lived until 1992. By the time she passed away (at nearly 18), she was blind, deaf, arthritic, epileptic, incontinent... I didn't view these as "issues" so much as just the inevitable accompaniments of old age; none really materialized until she was, I think, past 15 years old.

[Liz P]

I've reviewed the updated OFA website (updated since I was there last) which states what you have posted. Clearly I need to do more reading on the inheritance of complex genetics.

 

http://www.offa.org/pdf/hovanart.pdf

 

I think it is important to note that they reversed the terms for vertical and horizontal pedigrees. I was using the classic definition which places ancestors in a family tree format, therefore making the parents, grandparents, etc part of the vertical pedigree, while the siblings, cousins, etc were part of the horizontal pedigree. In their article, they read the pedigree quite literally as it appears on the paper with the ancestors being part the horizontal pedigree and other relatives being part of the vertical pedigree. The idea is exactly the same though.

[Liz P]

Don't know the answer to this question, but I had a Border collie who developed epilepsy at a relatively advanced age (15?) WAY back (in the mid-late 1980s?). That would be roughly 20-25 years ago.

 

I don't personally know any vet who would consider that to be (genetic) idiopathic epilepsy. Seizures in older dogs have an underlying cause such as a brain tumor (can be slow growing), stroke/clot, metabolic disease, infection, etc.

 

That is VERY different than a 2 year old dog developing seizures.

[juliepoudrier]

Eileen,

Your explanation makes good sense to me. I can imagine all kinds of combinations that would allow epilepsy to skip generations and also rear its ugly head when least expected.

 

Candy,

I believe it's possible that not only are there greater numbers of border collies being bred and therefore statistically more cases of epilepsy, but also that the incidence of the disease is being reported more often now, rather than being ignred/swept under the rug. (I am on a K9 epilepsy list, and the numbers/types of available treatments also seems to have increased greatly--comparatively speaking--so I suppose it's also possible that dogs diagnosed with epilepsy today have a much greater chance of having their seizures controlled, whereas it's likely in the past that such dogs might have been PTS. <--Just speculating there, but it makes sense to me that as medicine has advanced and seizures can be better controlled that people would opt for treatment vs. PTS.)

 

J.

[rushdoggie]

My epileptic dog came from a litter of 6 that produced 3 epileptic dogs (severe, cluster seizures). The sire was bought by the owner of the dam as a trained and good working dog to assist on their farm. They bred him to their female (who had been bred previously and those pups had no issues)and had the one litter. However, the sire had issues with their other male dog and started wanting to fight with him, so they sold him before the litter he sired reached adulthood.

 

When the breeder discovered there were multiple dog with seizures she contacted the person who bought the sire and also his previous owner, and this dog had been bred multiple times before and had never had an epileptic pup. So in their case, how would anyone know this would happen?

 

What disturbed me, maybe unfairly, is the new owner stated he would breed the dog again because he said he didn't care if he had thrown epileptic pups. He wasn't super friendly, and I have no idea if there were any issues with any future pups.

[workindogs]

So, if a disease (like epilepsy or CHD) is polygenic then one shouldn't worry about breeding either the sire or dam that had produced an epileptic pup as long as the cross is not repeated.....Right??? Because some dogs carry traits ABC and other dogs carry DEF and others carry ACE.

 

I guess what I'm trying to put my brain around (and maybe Candy, as well).....is what to do about a cross that has produced a polygenic disease like epilepsy or CHD? Are the sire and dam, regardless of the numerous talented and successful offspring produced, to be culled from breeding for producing a flawed pup ? What about the other 50% genetic contribution?

 

In the case of a successful sire or dam that has produced numerous talented pups, is that line doomed for producing a epileptic or CHD pup??

[Liz P]

I personally would not buy a pup whose sire or dam had produced epilepsy, even if it was in another litter. That is my opinion. You may feel differently based on the risks you are willing to take.

 

I neutered my dog with epilepsy and purchased a bitch who was not related to the side of his pedigree that seemed to be producing it regularly. I am playing the odds, hoping she is related enough to get the working traits I like but does not have the genes for epilepsy.

[Eileen Stein]

So, if a disease (like epilepsy or CHD) is polygenic then one shouldn't worry about breeding either the sire or dam that had produced an epileptic pup as long as the cross is not repeated.....Right??? Because some dogs carry traits ABC and other dogs carry DEF and others carry ACE.

 

I guess what I'm trying to put my brain around (and maybe Candy, as well).....is what to do about a cross that has produced a polygenic disease like epilepsy or CHD? Are the sire and dam, regardless of the numerous talented and successful offspring produced, to be culled from breeding for producing a flawed pup ? What about the other 50% genetic contribution?

 

In the case of a successful sire or dam that has produced numerous talented pups, is that line doomed for producing a epileptic or CHD pup??

 

Elizabeth, there are many different opinions on this, and some would say there's not enough knowledge to choose between many of them. Getting the broadest possible information about what has been produced close up in the two lines you're considering puts you in the best position to make a good decision. To continue the greatly oversimplified ABCDEF schematic, some dogs who have produced epilepsy could carry ABCDE, while other dogs who have produced epilepsy could carry only F. The pedigree data helps you estimate that -- you'll likely find more occurrences in the lines with the five genes than in the lines with the one gene, and that indicates greater risk.

 

But none of these genes has been identified AFAIK, and often you don't have access to a lot of data about related litters. The current state of our knowledge is such that IMO we couldn't be sure we'd be doing more good than harm by eliminating all dogs who have produced an epileptic pup from breeding -- we could well be doing more harm than good. The breeding recommendations of the ABCA's Health & Genetics Committee reflect this: Do not breed affected dogs. If two unaffected dogs produce an affected puppy, do not repeat that cross.

[workindogs]

Liz P

 

So, humor me with my crude hypothetical.

 

Popular Bad Ass Working Sire "Ben" produced 10 litters (out of different bitches) totaling 70 puppies. The crosses resulted in 50 talented working dogs (i.e. Open caliber....many in Open, competing at National levels, perhaps placing in Finals and the rest in proven working ranch positions) and the others working at various level and/or happy sporty/pet dogs. However, 1 puppy had epilepsy.

 

By your position, Bad Ass "Ben" should not be bred to any bitch......or, at the very least, no one should buy his puppies? Or maybe just you? His direct contribution to the gene pool should be stopped and maybe we should breed to a lesser working dog related to Bad Ass "Ben"...ie his brother? half brother? cousin?

 

Because, 1.4% of Bad Ass "Ben's" puppies had epilepsy (out of one bitch)...75% were very talented proven working dogs and 99% were actively pleasing their owners (whether working, sporting or being good dogs).

[Mark Billadeau]

All,

 

The OFA article I linked (above) does a good job decribing breeding where there is a polygenic disease issue present.

I highly recommend reading it.

 

 

Mark

[abcollie]

Liz P

 

So, humor me with my crude hypothetical.

 

Popular Bad Ass Working Sire "Ben" produced 10 litters (out of different bitches) totaling 70 puppies. The crosses resulted in 50 talented working dogs (i.e. Open caliber....many in Open, competing at National levels, perhaps placing in Finals and the rest in proven working ranch positions) and the others working at various level and/or happy sporty/pet dogs. However, 1 puppy had epilepsy.

 

By your position, Bad Ass "Ben" should not be bred to any bitch......or, at the very least, no one should buy his puppies? Or maybe just you? His direct contribution to the gene pool should be stopped and maybe we should breed to a lesser working dog related to Bad Ass "Ben"...ie his brother? half brother? cousin?

 

Because, 1.4% of Bad Ass "Ben's" puppies had epilepsy (out of one bitch)...75% were very talented proven working dogs and 99% were actively pleasing their owners (whether working, sporting or being good dogs).

 

That's where I'm having trouble also. Because IF this dog Ben is sired by a National, International, etc. champion ... then "odds are" you are talking about eliminating a LOT of dogs. I mean when you start researching pedigrees (because you have/had) an issue ... the same dogs come up a lot (I would find siblings *of Ben* that aren't well known but were used a lot).

 

I think MOST of us try and breed really great working dogs that are sound as we can make them (knowing perfect is impossible) and are just looking for as much info as we can get (and speaking for myself something I can understand since I'm math/scientist challenged :@)

[Kerales Farm]

Great discussion.

Here is another explanation of polygenic inheritance that is really helpful for us non-science folks to understand: http://www.ashgi.org/articles/breeding_bingo.htm

 

leslie

[juliepoudrier]

Liz is just one person, and her opinions are her own. I don't think she's recommending that everyone follow her own personal rules.

 

For my case, I probably would have considered breeding my bitch again, because I'm convinced it was *that specific cross* that was the problem. In Liz' horizontal breeding scheme,AFAIK, there would be nothing to have precluded either me (bitch's owner) or the stud's owner from breeding those dogs again (though obviously not to each other). My bitch has a ton of close relatives around and working, some very well known, some of whom have been bred quite a bit, with no incidences of epilepsy that I know of.

 

What Liz is saying is that had I bred my bitch again, she would not have been interested in a pup because my bitch produced pups with epilepsy. Instead, she would look at close relatives, half siblings and the like, who have NOT produced epilepsy.

 

Personally, I think if a dog produced one epileptic pup out of 70, and I really liked the dogs being mated as well as offspring already on the ground and working, I'd probably take a chance on a pup. BUT I would want the breeder to be up front about the fact that an epileptic pup was produced, so that I, as puppy buyer, can make an informed decision.

 

J.

[abcollie]

Great discussion.

Here is another explanation of polygenic inheritance that is really helpful for us non-science folks to understand: http://www.ashgi.org/articles/breeding_bingo.htm

 

leslie

 

Thank you! That was very helpful.

[workindogs]

Yes, very good article.

 

I guess my concern in my hypothetical "Ben" example is that his percentage of epilepsy is very very low.....yet his percentage of excellent working traits (also polygenic) is very very high. So by tossing out "Ben", you are tossing out his working genetics. In my mind, breeding to his brother might not be the same if his brother is a lesser dog. Since working traits are also polygenic and complex, the brother may not have the genetic "deck" as "Ben".

[Laurae]

Of course, the problem is that it is very difficult to truly know the percentage of epileptic pups that "Ben" has thrown...

[Cynthia P]

I'm finding this very interesting as I have one puppy out of a litter 4 years ago that has had 4 (i think) seizures. None of the littermates have had any seizures, none of a previous litter from another cross, none of the dam or sire lines are reported to have any seizures (and I believe that both of the working breeders have told me the truth). The sire is a good open dog, better than his handler and a great farm dog. The bitch won't be bred again because she is 11. But we have been contemplating breeding the littermate bitch we kept (and yes she is in open and she is quite good, albeit quite plain).

 

Breeding is a very tough proposition and having a pup out of litter that has some problems makes everything more confusing. I've been doing lots of research and thanks for the discussion

 

Cynthia

[Liz P]

What Liz is saying is that had I bred my bitch again, she would not have been interested in a pup because my bitch produced pups with epilepsy. Instead, she would look at close relatives, half siblings and the like, who have NOT produced epilepsy.

 

What Julie said. That is exactly what I have done with my dog that I really liked a whole lot who had epilepsy. I purchased a dog who was related but farther back in the pedigree and via a littermate sister to the one who produced my dog with epilepsy. I still wanted the good working genes but hoped to reduce my odds of getting a pup with epilepsy.

 

And again, that is my opinion. I am not saying you should or must share it.

 

I would also like to quote myself from earlier in this thread and say again, "this is not a black and white issue." It is very complex and we can't lay down easy to follow, hard and fast rules.

 

In my example, it was sons of the the hot shot dog who produced epilepsy at a fairly high rate, making it an easy enough decision to go back to the hot shot stud for the same genes but hopefully a lower risk of epilepsy. If Mr. Hot Shot Stud himself produced epilepsy in 1% of his pups when bred to a wide variety of unrelated bitches, his owner would have to make a decision based on his/her own comfort level.

 

The problem I have had in the past I will call "the tip of the iceberg effect." With my own dog I initially found one or two relatives with epilepsy. It took careful research over nearly a decade to locate the dozens of affected relatives. Some breeders do a fantastic job of covering up health problems in their lines.

[abcollie]

Thanks for all the info guys ... every little bit helps. I do think "we" (as in Border Collie breeders) need to talk about this. It's "kind of" where CEA was years ago and we seem to have "worked" through that. I always liked the way ABCA did it (not banning dogs like they did in the UK). I think they lost a LOT of good working dogs by doing that.

 

Do you think it's possible to get a genetic test done for epilepsy or early onset deafness like we did for CEA or they totally different?

[juliepoudrier]

Genetic tests for both are being worked on now, but especially with epilepsy, the polygenic nature will make it much more difficult to isolate all the genes responsible and then figure out what combinations cause actual disease and then develop a test for them. A genetic test for EOD was supposed to be ready about now, but I think the researchers ran into some problems and so it's been delayed.

 

J.

[abcollie]

Genetic tests for both are being worked on now, but especially with epilepsy, the polygenic nature will make it much more difficult to isolate all the genes responsible and then figure out what combinations cause actual disease and then develop a test for them. A genetic test for EOD was supposed to be ready about now, but I think the researchers ran into some problems and so it's been delayed.

 

J.

 

Thanks! Hopefully soon ...