How to read a pedigree to breed better pups

The journey to a litter of healthy good looking working retrievers begins long before any actual breeding takes place. Much more than just the sire and dam goes into creating potential pups; after all, Mom and Dad had to get their genes from somewhere. That "somewhere" is their parents and grandparents, etc. - the pedigree. Learning to read a pedigree isn't hard, but actually doing it takes quite a bit of time as there are usually many factors that need to be researched, and each one requires its own search. So, if a breeder is looking for how likely it is that a given breeding will produce larger size, a certain type, good hips and no seizures, at least four separate searches must be done.

I don't know how size is inherited, but type, hips and seizures are determined by multiple genes, like pretty much everything a dog inherits; I think only color in Curlies is determined by simple dominant/recessive genes. So, the point of pedigree research is to figure out the odds that the genes the breeder wants will come together in the majority of the pups in a litter, which is why it is important to look past just the parents to at least the grandparents, even better - much better - well beyond them.

What brought this to mind for me was a bit of research I did on a proposed litter another breeder was doing. I doubt the breeder is aware, but every last one of the 16 dogs in the 4th generation of the pedigree goes back to known seizure producers, with SEVENTY-THREE lines back to one dog that was fairly prolific for siring seizures. I know there are people out there saying, what does it matter if that dog is so far back? It matters because he is all over that pedigree, so whatever genes are responsible for seizures have to had come thru at least once, but more likely many times, especially since that 73 is pretty evenly spread out in the pedigree. A check of the known seizures list that Maija Paivarinta sends out shows that seizures have indeed shown up in some more modern day dogs, in one case from father to son. So, the odds of at least some pups in this proposed breeding ending up with seizures is fairly high, due to the sheer number of places the genes may have come forward from.

Another way to read a pedigree is for depth; this is looking at littermates of the dogs to see how they were for whatever trait the breeder is looking for. An example is hip dysplasia; using dogs with depth for cleared hips makes it much more likely that resulting pups will also have clear hips. Even if a dog with OFA Fair dog is chosen over a dog with OFA Good hips, if the Fair dog has more clear siblings than the Good dog, it is more likely that the Fair dog will produce clear pups due to a concentration of "good" hip genes in his pedigree.

The easiest way to read a pedigree of a proposed breeding is first to look at the surface - how many of the dogs in the pedigree are OFA, CERF, fully coated? Did any seize or have heart problems? How many field titles are there? How many of these dogs have you had a chance to see in person, to touch? Then, do depth on any pedigree that makes it thru a surface check - how many siblings of the dogs in the pedigree OFA'd, CERF'd, were fully coated? Did any seize or have heart problems? What is the depth of pedigree for field work traits?

Of course, with some of this the breeder has to trust they are being told the truth, since we don't have a testing database for coat or quality of field work. Even with absolute truth, not all Curly people understand what fully coated is, and even less understand the different skills a good field dog needs. The best thing to do is to actually go LOOK at these dogs, as many as possible. Attend the specialty and watch the dogs in the ring, in performance and in the field. Then write everything down on a pedigree to see the relationships, like this -

Sometimes color coding things helps make the different relationships clearer. This example isn't all that good for reproduction since it's hard to see the text, but on a computer, it works quite well. It shows that almost all of the dogs in this proposed breeding have clear hips, though as you get further back in the pedigree, there are dogs with no info. Sometimes this is because of imported dogs, sometimes because the dogs are far enough back that x-raying hips and checking eyes wasn't common during their time. Or, it could be that the dog was x-rayed but didn't pass OFA - all of this needs to be taken into consideration. In this pedigree, given that all of the dogs in the first three generations have cleared hips and eyes, odds are better that the proposed puppies will also pass, or only be mildly affected, especially in the case of hip dysplasia. Depth of pedigree, later on, will give more information on that.

This pedigree also shows how some of the field qualities have been handed down through the generations. The parents both look like good field dogs, the paternal grandparents show really no info, but then behind them we see the littermates Bob and Bud, both FChs with specific information on their marking ability and the fact that Bob tended to break. Given that they are FChs, the assumption can be made that they were both at least moderately biddable, had drive and did well in water. Since the litter brothers are Sam's grandsires, and Sam himself is a nice worker, good marker and very biddable, the assumption can be that Sam can reproduce these qualities, hopefully in a majority of the puppies.

On Carrie's side, we have FCh Bud again, further concentrating the good field genes, especially since he is close up in the pedigree as Carrie's sire. Carrie's dam Flower is a negative, in that she avoided water in the field and there really isn't much in the way of good field information behind her, but since she was bred to Bud, and daughter Carrie is a good worker, good in water and very biddable, there is a better chance that Flower's genetic contribution will not show up in many of the pups, if any, in a litter sired by a dog with Bud and Bob as the paternal grandsires. However, it is a good idea for the breeder to test the pups in water as early as possible to see if any water avoidance was passed down.

Again, depth of pedigree would give more information on this. I only did a depth of pedigree example for hips and eyes, but the same thing can be done for any other genetic traits a breeder is looking for. In the case of this field pedigree, if the siblings of Flower and her ancestors had more field information, a more informed decision could be made about how likely it would be she would pass on the water avoidance.

Depth of pedigree; in this example, we are looking at how many siblings of the dogs in the pedigree have information on hips, eyes and hearts. There have been scientific studies that show that the deeper a pedigree is for clear hips, the more likely any given pup will grow up to have clear hips, but the reality of life is that for the most part, only those dogs that might be used for breeding are likely to have their hips x-rayed, and it is mostly only those that have a good-looking x-ray will have it sent to OFA. So, educated guesses must be made, which are more likely to be correct in the case of hips since a pass at two years is considered good for life, whereas eyes should be checked into old age which most folks don't do. Things are even harder when it comes to hearts, since we have only really been checking them for a much shorter period of time. Not to mention we don't even know how most heart issues are inherited! However, it all works the same - the more clear dogs with clear siblings a pedigree has, the more likely it is that individual puppies will also be clear.

Pedigree analysis also works for less important issues like certain head types, size, etc., showing how likely it is that certain traits will be carried forward from parents to puppies, based on how often those traits show up in the ancestors. This is one way to avoid "surprises"; getting pups with poor rear movement from two nicely moving parents could have been predicted by researching the pedigree to see what the rears of the dogs behind the parents looked like.

Pedigree research - so important, so easy, but so much work!