The Recessive Yorkie
 

Below is a list, taken from Ann Seranne's The Joy of Breeding Your Own Show Dog. It is a list of traits generally agreed to be either dominate or recessive. With the Yorkshire Terrier having a high percentage of desirable traits being recessive, it's no wonder that this is an incredibly difficult breed to breed correct and pure.

Dominant .... Recessive
Long Head .... Short Head
Large or Long Ears .... Small or Short Ears
Low-set Ears .... High-set Ears
Wide Ear Leather .... Narrow Ear Leather
Coarse Skull .... Fine Skull
Short Foreface .... Long Foreface
Erect Ears .... Drop or Tipped ears
Dark Eyes .... Light Eyes
Normal Eyes .... Large Bulging Eyes in Some Breeds
Brown Eyes .... Blue Eyes
Wire Coat .... Smooth Coat
Short Coat .... Long Coat
Curly Coat .... Straight Coat
Poor Layback of Shoulder .... Good Layback of Shoulder
Poorly Angulated Stifle .... Well Angulated Stifle
High-set Tail .... Low-set Tail
Heavy Bone .... Light Bone
Deep Chest .... Shallow Chest
Straight Topline .... Swayback
Good Spring of Rib .... Poor Spring of Rib
Short Stifle .... Long Stifle
Light Pigment .... Dark Pigment on Skin of White Dogs
Normal Hearing .... Deafness
Good Eyesight ..... Night Blindness
Good Eye Pigment .... Walleyes
Self-color .... Parti-color
Black Nose .... Dudley Nose
Good Mouth .... Overshot or Undershot
Normal Palate ..... Cleft palate
Normal Lip .... Hare Lip
Straight tail .... Kinked or Bent Tail

It is noted that some are incompletely dominate, some are linked to others and others, such as cleft palate, are considered lethal genes.

Could we use this list as a basis to discuss breeding Yorkshires? Genotype vs phenotype, line-breeding, in-breeding, out-crossing, linked genes, etc. are all possible subjects for breeding healthy, typey Yorkshire terriers. I know many of these aspects have been previously discussed, but it might be nice to see them discussed in a cohesive manner with your own personal experiences.

Thanks in advance for your input.

I have this book...very interesting!

Dont you mean Yorkshire Terrier having a high percentage of desirable traits being dominant??

I think you mean the dominant traits are more desireable:confused:

No, I mean that many of the desirable traits, particularly those dealing with the ears and coat, are considered genetically recessive.

it's easir to breed for a recessive trait since breeding two recessive together will always breed true. For example if you breed two partis together you will only get partis.

Point taken, and I agree with you about the partis. My understanding is that it's the piebald gene that expresses the white color.

I don't think that logic is true for all recessive traits, however. Not all traits are governed by a single pair of genes. For example, I have a boy and girl, both with long silky coats. I have bred them twice and, with the first litter, all the pups had gorgeous, long, silky coats. With the second breeding, I got 3 pups with the long coats and one with a slightly wiry coat. Since the long, straight coat is the result of recessive genes, one would think that both parents would breed true if there was only one pair of genes controlling these factors.

There are a lot more traits on the list than just ears and coat though and most of THOSE are dominent so I would say overall, the overall quality of the yorkshire terrier is dominant.

This is easily explicable! Both of your yorkie parents are CARRIERS of dominant and recessive traits. This is called heterozygous. To be heterozygous means to have one dominent and one recessive allel given. Each allel is passed on by the parents of the pups. Therefore each pup can have a different geneotypic ratio which expresses different phenotypes. The different combinations for lets say a silky coated pup from two heterozygous parents can be SS (which is silky), Ss (which is silky), sS (which is silky), or ss (which is wirey). The reason for this is as long as a dominant trait (S) is given to the puppy the puppy will have a silky coat. If the puppy obtained both (s) then the puppys coat will be wirey.:)

My understanding from what I've read is that a dog that displays a trait known to be recessive had to have inherited this gene from both parents and would therefore be homozygous for that trait, for example, two partis producing only partis. So how could two dogs that both exhibit the trait of a recessive gene produce other than that trait unless that trait is governed by more than one pair of genes?

I will say that both the sire and dam I mentioned in an earlier post do have long silky coats but both exhibit a slight bit of waviness along the hindquarters. The pups from the first litter show no hint of waviness in their coats. I did keep a girl from that litter but have not bred her yet so am unsure of what to expect. My thought is that if I use a male with a fully straight coat that I would see the pups have straight coats.

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My breeding philosphy
 

As a show breeder who has produced at least one champion from every litter of yorkies I've produced (one litter of 4 produced 3 champions), I can tell you that kennel blindness will destroy your breeding program in a heartbeat. Here is my breeding philosophy:

1. Seek out knowledgeable individuals who will honestly critique your bitch and tell you what needs to be improved. This person needs to feel they can be brutally honest, and you need to be able to take the criticism gracefully.
2. Breed each litter as if it is the last litter your bitch may ever produce. Money wisely spent on a quality stud will be money saved on handler and show expenses. The fact that you own a male, even if it is a champion, does not mean you should use that dog on every bitch you own.
3. Breed to the stud dog that most closely resembles your ideal dog. Be extremely critical of that dog and be sure that the traits that dog possesses are the same as those you need to correct in your female. Do not breed to anything that has faults you cannot live with, as you are bringing those traits into your gene pool. It's wise to know what the stud's parents looked like as well. Ask for referrals and talk to those other breeders to understand what the stud produces. Ask about faults, genetic problems and most of all, ask about litter size and puppy mortality. Consistent litters of 1 or 2 puppies can be indicative of a problem which causes fetal death and the puppies to be reabsorbed.
4. Look at what the stud dog produces. Sometimes you are better off breeding to the father of that lovely dog you see in the ring if the mother did not possess those traits you admire in that dog. Remember, a "proven" stud dog doesn't simply mean the dog is fertile. It means that the stud transmits it's desireable traits to it's offspring on a consistent basis. If have the opportunity, learn about entire litters sired by that dog, including those that were sold as pets and why they didn't make the grade.
5. If you are breeding to show, find out how many champions that dog has produced. A huge stud fee doesn't necessarily equate to quality offspring. Keep in mind, not all specials are truly the best dogs in the country, but rather their owners have the resources to campaign the dog. You might find a really great stud dog owned by a small scale show breeder that will produce the results you want without a massive stud fee.

In my opinion, the reason people practice line breeding is because they do not have a comfort level with knowing what traits to expect from a dog. So they go the safe route and hope for the best. If you can be honest with yourself about what you would choose to improve your female and breed to a dog that produces those traits, you will have a great level of success.

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Thanks, Rosanne, for your comments. I can fully appreciate what you say about kennel blindness. I do try to keep a critical eye on my dogs' qualities and faults.

With my first breeding of the pair I mentioned, I was very pleased with the results. I kept all 3 pups until 9 months of age as I wanted to see them develop to know what I was producing. I also had a show breeder friend evaluate my pups, I placed two of them and kept a female. The male from the litter is in my avatar photo.

I have not got into showing yet. My exhibitor friend recently saw my female that I kept and thought she was show quality except for the fact that I had spoiled her and she doubted her attitude in the ring. I admit she is right for she was a wonderfully spunky girl that has become a ninny baby LOL. So I have to work on how I raise my pups to maintain that attitude necessary.

As for my pup's parents, I know the dam's lineage well as well as the sire on his paternal side. I don't know so much about the maternal side and feel that may well have been where my surprise pup came from in the second litter. I hope to breed my dam to my sire's father next time to hopefully give me more consistent quality.

I'm a little surprised by your comment that line breeding was going the safe route. I would think that line breeding would involve more consideration and that seeking an outside stud would be the easier thing. I'm not being critical...just a little surprised. More food for thought, I suppose.

Thanks again for the response. It is much appreciated.

I'm a little surprised by your comment that line breeding was going the safe route. I would think that line breeding would involve more consideration and that seeking an outside stud would be the easier thing. I'm not being critical...just a little surprised. More food for thought, I suppose.

Thanks again for the response. It is much appreciated.[/QUOTE]

When you line breed it is a safer route because you know the type of yorkie your producing...when you introduce an outcross your really not sure what you are getting when you bring in the outcross...did that make sense?

Donna Bird