Eskie puppies

[eskilady]

This is a picture of 2 day old American Eskimo puppies. There are 4 females and 2 males in this litter and we are going to get one of the males. I have picked out the green one. Actually, we won't know if we are going to take one of these puppies until they have been optigen tested and we know one of the boys is a pattern A. Cross your fingers for us, ok?

[oc_spirit]

Ok I really didn't understand that breeder terminology but I do know that those puppies are the sweetest little darlings!!!!

[WingedFoal]

I'll keep my fingers crossed for you even though I have no idea what any of that meant either!!

[eskilady]

Eskies have a hereditary eye disease called PRA (progressive retinal dystrophy) but a company called Optigen has discovered a test for it. So a pattern A means that the dog is clear; pattern B means that he is a carrier and pattern C means that he is affected. We need a pattern A to breed to our pattern C females. I will keep you all informed of the results when the breeder has them tested.

[Owned by Lucy]

Why would you want to breed a whole litter of carriers?

[Bingo]

How cute. They're so perfectly aligned!

[FurryAngel33]

Originally Posted by Owned by Lucy

Why would you want to breed a whole litter of carriers?

Because A is all Dominet genes like AA
C is recesive, aa
B is a Hybred they only carry it and then the pups wont show up as carring it because the one dominet gene blocks out the resecssive. Hybred Aa

understand? then the pups don't have any chance in the world if they get a pup with and A, to breed c's.

Punnet Square A A
a Aa Aa
a Aa Aa All would be a B a hybred only carriers

[sheltiepups]

They are adorable.. why are they green?

Furry, I think I understand.

[Owned by Lucy]

I understand the genetics of it and that there is no chance of any of the pups being effected but every single one of them will be a carrier for this disease. So while they may not display effects of the disease they have the potential to pass it on to their offspring if they mate with another carrier or an affected individual. Shouldn't the goal be to breed out the trait instead of just masking it. Why breed an animal that posses this defect? Why not breed the healthy animals that are not affected or carriers of the trait? This would be the best way to ensure the health of the breed.

[calgal]

They are the sweetest little things yet!! Oh how I would love to pick them up and give kisses right on those cute little pink noses.

[eskilady]

Actually, the whole litter will not be carriers. Because mom is an A and dad is a B, the litter will be mixed. We are trying to breed out the disease but the gene pool for the American Eskimo is so small that if we didn't breed the Cs, the gene pool would be that much smaller so by breeding a B or C to an A, we will get some As and then we take those As and breed them to another A and we can wipe the disease out but it takes some time. And the pattern A dogs do not have the the gene and are not carriers so cannot pass it along. The Bs are carriers and can pass it along and the C's have the highest chance of becoming blind in the future. Oh, by breeding our C females to an A male, we will get a litter of B, who are carriers but people who are just buying pets don't really care if their dogs are carriers as they are sold on a spay/neuter contract. The B puppies will have to be bred to As and we will have more As. Does this make sense? I am not sure how it works but I know that it does.

And they are green as a result of their birth. The green will wear off in the next couple of days.

[ChiChi]

awww! i am not gettin in to the whole punnet squares.. ugh i hate punnet squares... but those pups r great! so go for the A! LOL!

[Owned by Lucy]

The inheritance mattern you described (and the information I found on the disease elsewhere and is quoted below) is that of a recessive trait so there are three positions that can be inherited. Using your terminology, "pattern A" will be homozygous normal (two normal alleles), Pattern B is a carrier (one normal and one mutant allele) and Pattern C is affected (two mutant alleles). If you have a dog that is not affected and is not a carrier (pattern A - AA) breeding with a affected individual (pattern C - aa) by definition there is only one combinationall of the puppies will be Aa. There are no other options except that all of the dogs will be carriers and able to pass the disease.

Autosomal recessive

This is the most common mode of inheritance for genetic conditions in dogs. Progressive retinal atrophy (PRA), which causes blindness in many breeds, is such a trait. To be affected, the animal must inherit 2 copies of the gene (genotype pp), 1 from each parent. Dogs with the genotype PP (normal) or Pp (carrier) will be clinically normal but the carrier will pass the affected gene to approximately half the offspring. As long as carriers (Pp) are mated to normal animals (PP), the offspring will be unaffected but some will remain carriers. If 2 carriers are mated, some of the offspring (approximately 25%) will be affected.

example:

Looking the chart you will see that crossing a normal (non-carrier) dog with a affected dog you will get ALL carriers. There is no where for a puppy to inherit two alleles from a single parent so there is no possibility of getting normal pups that are not carriers. The only mix that creates both normals and carriers is the matting of 2 carriers but you will get as many carriers as you get normals.

[oc_spirit]

I understand Punnett Squares fine (am just finishing Gr 11 biology this year) but even if a pup is Aa that recessive trait when crossed with an aa can still result in an aa pup which means a pup with the disease. The only way to ensure a pup will NOT get the disease to breed AA with an Aa or AA with AA. So long as the recessive gene is there the pup may not show symptoms of the disease but can pass it on to every single one of it's offspring. If I were a breeder I wouldn't care how small the gene pool is, I would only breed Pattern A dogs regardless of the fact that that would probably mean breeding once every few years (since a CH Pattern A dog probably is rather rare) because it would be more important to me to bring genetic disease-free pups in the world than widening a gene pool with carriers of a disease because due to so many BYBs out there along with them would be tons of eskies that are Pattern C so if Pattern B gets crossed with Patter C you get Aa with aa which means a chance of aa pups whereas as AA with say, aa is still a healthy Aa and AA with Aa is AA and Aa. In other words, there's room for that flaw which can still be bred out without dogs actually getting the disease.

[oc_spirit]

Alright Owned by Lucy just explained it a LOT better than me with that handy visual LOL