I'm really confused about this with regard to mixed breed dogs (a/k/a "designer dogs"). It does seem somewhat logical to me that if you breed two different breeds together that don't have the same hereditary health issues, you'll end up with pups that don't have either of the breed's health issues, demonstrating hybrid vigor. BUT, if you breed two breeds that DO have the same hereditary health issues, you're going to end up with pups that could be affected/afflicted by the issue.
I started thinking about this with regard to Fanconi Syndrome actually. I had always thought that hybrid vigor was a "selling point," so to speak, and completely untrue, but from what I've learned (or, at least, thought I learned, about the way FS can be passed on), breeding (doG forbid!) an FS-affected Basenji dog with, say, a Shiba Inu bitch (which, as far as I know, is a breed not known for FS), would get you puppies that can't possibly have FS and, thereby, exhibit hybrid vigor, by being more healthy than their sire.
I realize the above is a very simplistic view of how genetics work and that there's much more involved than I know. Can anyone enlighten me? Thanks!
Hybrid vigor is a real phenomenon. I'm not an expert but I think basically when mixed breed dogs are bred together, the offspring are less likely to have certain genetic disorders because it's less likely that the parents both have the gene required for the disorder to exist. It's like the opposite of the problems that occur when dogs are inbred.
This phenomenon is also true for humans of different races mating (sounds romantic, huh? ha ha) … My Korean friend married a Swedish woman and their obstetrician said that there are a bunch of diseases that their baby will be HIGHLY unlikely to be susceptible to because of hybrid vigor.
I do know that fanconis does exist in other breeds as well as in humans.
Otherswise, I am at a loss to help you with this question.
I do know that fanconis does exist in other breeds as well as in humans.
Otherswise, I am at a loss to help you with this question.
Yes, thank you, Sharron, I was aware of that. I was just using FS as an example, I guess. It could be any inheritable health issue.
Lot depends on if the gene is dominate or recessive… what would or would not be passed on.... Both parents do not need to have the gene for a genetic problem.... so without knowing the total health behind both breeds you are breeding in the dark, totally....and most people do the designer dogs for things like shedding... someone would need to explain to me if you mix a poodle with a golden, why you would think it would not shed?
Hybrid Vigor is often used incorrectly as a selling point for mixed breed dogs. In order to have Hybrid Vigor the two parents would have to of different species. In other words, mules, ligers, tions could exhibit "hybrid vigor" because they are truly hybrids the mixing of two different species. Dogs can not because they are not different species.
As for the idea that mixed breeds will be healthier than mutts. That is only true if all inherited disorders are simple recessives and the disorders exist only in one breed. Since all dogs are of the same species this is not a good assumption. Some disorders are dominant, some are polygenic and most are in many breeds with a difference in the frequency of the gene so though a disorder may be rare in some breeds the gene can still be there. So it may be that some mixed breeds are healthier than their parents but some are actually less healthy than either of their parents.
And to add to Lisa's excellent post, with mix breeds, no one is keeping health records, so who is to say that they are or are not healthier?… at least with purebreds responsible breeders know the health concerns and tell prospective buyers...
Hybrid Vigor is often used incorrectly as a selling point for mixed breed dogs. In order to have Hybrid Vigor the two parents would have to of different species. In other words, mules, ligers, tions could exhibit "hybrid vigor" because they are truly hybrids the mixing of two different species. Dogs can not because they are not different species.
As for the idea that mixed breeds will be healthier than mutts. That is only true if all inherited disorders are simple recessives and the disorders exist only in one breed. Since all dogs are of the same species this is not a good assumption. Some disorders are dominant, some are polygenic and most are in many breeds with a difference in the frequency of the gene so though a disorder may be rare in some breeds the gene can still be there. So it may be that some mixed breeds are healthier than their parents but some are actually less healthy than either of their parents.
THANK you Lisa! I was so dreading having to find the right words to explain what you have so clearly stated above!
You can't have a hybrid with parents of the same species!
I can think of several inherited diseases that happen in occur in mixed breed dogs as well as pure bred dogs: thyroid disease, autoimmune diseases, hip dysplasia, and of course cancer (though I suppose it is debatable about it's level of inheritance)
I guess the definition of hybrid is debatable. From Merriam-Webster OnLine:
hy·brid
Etymology: Latin hybrida
Date: 1601
1: an offspring of two animals or plants of different races, breeds, varieties, species, or genera
2: a person whose background is a blend of two diverse cultures or traditions
3 a: something heterogeneous in origin or composition : composite <hybrids of="" complementary="" dna="" and="" rna="" strands=""><a hybrid="" of="" medieval="" and="" renaissance="" styles="">b: something (as a power plant, vehicle, or electronic circuit) that has two different types of components performing essentially the same function.
Thanks for the info. I am enlightened!</a></hybrids>
Hmmmm….that is interesting. I learned in school that the biological definition is between species. I don't think there CAN be a hybridization between genera...if anyone can think of one that exists let me know. Now I am really curious...I have Tim working on the query 
Hmmmm….that is interesting. I learned in school that the biological definition is between species. I don't think there CAN be a hybridization between genera...if anyone can think of one that exists let me know. Now I am really curious...I have Tim working on the query
From what I've read, the "beefalo" (or "cattalo") is a cross-genera hybrid. CattleXBison.
I tell this story often - I was in a vet office and in came a puggle - being seen for an 'eye thing' on one eye. It was Cherry Eye - a problem noted with beagles. I asked if they had entropian in the eye first - they said no but they had that in the other eye. (Basenjis can have this but PUGS do a lot) as well as the same eye had Kertoconjuctivitius (dry eye) also a pug thing.
Both breeds have issues with PRA - so here was 1 eye with a beagle thing and 1 eye with a pug thing - so much for hybrid vigor.
I have a Puggle and his eyes are constantly watery, poor guy. I haven't had many problems with him though, anal glands are always full and running eyes that's it. He also snores like a Mack truck (or maybe that is me snoring and blaming it on the dog)!
To add another thought to the mix– species can develop problems because of inbreeding-- as in cheetahs, or any zoo animals. That is why zoos borrow animals from each other for breeding programs. The addition of new basenji's into the US breeding population in the last 10 years-- has very likely reduced the chance of some of the common basenji-specific diseases. Also the brindles are beautiful!
Kris
To add another thought to the mix– species can develop problems because of inbreeding-- as in cheetahs, or any zoo animals. That is why zoos borrow animals from each other for breeding programs. The addition of new basenji's into the US breeding population in the last 10 years-- has very likely reduced the chance of some of the common basenji-specific diseases. Also the brindles are beautiful!
Kris
It has increased the size of the gene pool which will help to reduce Basenji specific problems, depending on how those dogs are bred…. But those dogs were not without health concerns that need to be considered also... again, it comes down to testing... and knowing what you are breeding and to who....
My all-time fav is to hear how wonderful a labradoodle is and how healthy they are….
I mean, a stinky hairy lab bred to a poodle and they think that there will never by any issues?? Hihgly unlikely.
Even better, the most common issue with both breeds is PRA (progressive retinal atrophy, aka 'gradual night blindness"... so the resulting puppies are not any better off when it comes to PRA !!!
DOH!! :eek:
I deal with nutrition and not genetics but I do think that hybrid vigor applies to breeding two genetically different individuals, this can apply to two different breeds within the same species.
The problem with designer breeds is that one generation does not constitute a new breed. I'm not sure about dogs but in cattle you have to have at least 5 or 6 generations before the offspring are considered close enough genetically to be a new breed. When people cross two breeds, like a labrador and a poodle, you can never be certain what characteristics you will get. From the first generation, if you put two adult dogs side by side it is unlikely you could recognize them as the same breed. To make long story short a cross from the first generation, at least from the animal science perspective, is not a new breed.
In my opinion it isn't very responsible to breed indiscriminately because something looks cute. Designing a new breed with a specific working purpose and end goal in mind is something I don't have a problem with but I just don't think that most designer dog breeders have the knowledge to do this appropriately.
darn and here I was going to borrow a Shi Tzu bitch to breed to my basenjis new breed name: BASHItZ - I think that works don't you
Hmmmmm, I think you'll have to work on a few generations with that one-long hair, erect ears, bug eyes, long muzzle, short legs-I don't knoooowwww!
Naw with good marketing I think the american public will buy anything! Sad comentary isn't it.
