Genetics

What is a Dog?

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There is and will always be considerable confusion among dog fanciers and other publics in regard to breeds of dogs and their relations to other dog-like animals. One of the words that some of us maintain is misused or, at least, used by various people in different ways, is “hybrid.”

Many dictionaries inadequately define hybrids as being “individuals produced by breeding (crossing) different races, varieties, species, etc.” Disagreements arise when the correspondents do not agree (even temporarily) on the same definition. If you include wolves and domestic dogs in the same grouping because there is no hindrance to one fertilizing the other and resulting in equally-fertile offspring, then I cannot agree to call the result a hybrid. No more than Chinese and Caucasian humans’ children are hybrids. A better term for either might be “mixed” (we use the term “mixed-breed” in speaking of dogs, but usually “mixed heritage” re humans). Since canids mate and produce offspring which in turn are just as fertile, I feel it is wrong to call them hybrids. Dingoes, coyotes, wolves, and domestic dogs are all really breeds of Canis (dogs, canids). Their offspring should not be called hybrids, but rather “crosses” just as we would call a Cockapoo a “cross.”...

Type and Style Variability in the German Shepherd

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I have written in a few publications before, on the topic of genetic diversity, linebreeding, and health, and am now living up to my promise to the club leadership to supply another article on the related topic of phenotype variability as it relates to genotype. That is, “What you see is a clue to what you got.” (“Got” here means “obtained,” not just the teeny-bopper’s or Valley girl’s misuse of the word when they mean “have.”) For it is what you got from the breeders of your dog and its ancestors that you have to work with. If you are a non-breeding owner, you will want to read this to understand more about your dog’s appearance and health...

Mystery of the White Shepherd

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The white dog has been in the population since before the beginning of the German Shepherd Dog; that is, the color variety has existed since before recognition as a distinct breed. When the GSD began to be recorded (registered, identified by name and number) and an association formed for that purpose a decade before 1900, there were various “styles” or types used by sheep herders and other owners. There were heavy-bodied dogs with hanging ears similar to those of the Pyrenean flock guardian...

The New Knowledge of DM (“GSD Myelopathy”)
Part 11

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The finding of CDRM in several littermate pairs, combined with the acknowledged high incidence of the disease in the German shepherd breed in general suggested that a genetic factor may well be involved in the aetiology of the disease, as previously suggested  (Clemmons, 1989). Due to this unusually high incidence of CDRM in one breed of dog and the discovery of at least two pairs of affected littermates, the investigation of a possible genetic factor was indicated. Following a literature search for diseases in other species with clinical and pathological similarities to CDRM, a working hypothesis was...

EFFECT OF ESTRUS AND OTHER FACTORS
ON APPARENT HIP JOINT CONFORMATION

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Before we get into the meat of the matter, let’s review the OFA-type definitions of canine hip dysplasia, referred to here as HD.

A Beginner’s Guide to Coat Colors
With Special Attention to the GSD

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  It has been said that there are only two colors in dogs, at least in their coats. This is as true as saying there are only three primary colors in pigments for inks, paints, etc., and that most others are blends of those three. Even truer, for eumelanin (dark or black pigment) and phaeomelanin (yellow pigment) are the only chemically differentiated forms of melanin, the coat’s color substance. The various shades of brown, tan, red, and cream depend on the concentration of phaeomelanin in the hair shafts, the shape of the crystals, and other factors. Certain genes called modifiers can act on the major ones to cause the black to look blue or chocolate. White is not technically a color, but the absence of pigment...

Another Look at Elbows

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The elbow is called a synovial (lubricated) hinge joint, although it has some minor similarity to a ball-and-socket joint. There is not that sort of rotation that we find in the hip; the twisting of the lower arm is possible because of the design of the radius. Mainly, flexion and extension are the movements in the elbow itself. The ulna acts to add stability and restrict motion, and the radius bears most, perhaps up to 80%, of the weight of the forequarters.

CARPAL SUBLUXATION and WEAK PASTERNS—TWO DIFFERENT CONDITIONS?

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There are two pastern disorders that are often confused until one actually has seen the “extreme” type. The severity of “weak-by-genetic-neglect” wrists seen in many German Shepherds can approach the other type at first impression. In addition to these two, there are cases of retained cartilage and the unequal or asynchronous growth of the two bones in the lower forearm, but these are not included in the subject of this section. I constantly see variable expressions of pasterns changed by growth plate disturbances, with some dogs having a valgus (turned-out) deformity of only one carpus, some with little turning out, many with both feet pointing “east-west.”

Color Inheritance in the Boerboel

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It was my pleasure to deliver a series of illustrated lectures in the Republic of South Africa at the invitation of a coalition of the South African Boerboel clubs in January 2011. One seminar was on the subject of hip dysplasia and other orthopedic disorders, and the other was on gait and structure. The first set was in the Johannesburg-Pretoria area, and the following weekend it was near Durban on the Indian Ocean coast. Both were attended by enthusiastic groups of novices and experienced breeders representing the three or four Boerboel breed clubs in the country as well as fanciers from Belgium and the United Kingdom. After the slide presentations...

Earthdogs - Size and Proportions of the Cairn & Others

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The game is the same (go to ground, in the quarry’s lair, and flush or drag him out), but the “game” (in the sense of what species is being hunted) will vary a little in size from the small rats to the large otters. Despite a miniscule percentage of terriers ever likely to be asked to enter a burrow after such prey or pest, the purists in the world of dog fanciers want the breed to remain true to its original purpose.

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