Cynologist
Cynology: Puppies DogsArchive for the ‘Genetics & Heredity’ Category
Affenpinschers
Patella luxation, either medial or lateral; Legg-Calves Perthes disease
Brussels Griffon
Shoulder dislocation
Cavalier King Charles Spaniels
Patella luxation; Episodic weakness and collapse, a rare, inherited disorder
Chihuahuas (Long and Smooth coats)
Shoulders dislocation; Patella luxation, medial or lateral; Hypoplasia of dens, which produces atlantoaxial subluxation, causing neck pain and quadriplegia
Chinese Cresteds
Medial patella luation; Legg-Calves Perthes disease
English Toy Spaniels (Blenheim/Prince Charles and King Charles/Ruby)
Patella luxation, medial or lateral can occur with medial the most common, Congenital Femoral Shift
Italian Greyhounds
Predisposed to forelimb fractures
Japanese Chin
Dwarfism
Maltese
Patella luxatin
Miniature Pinschers
Shoulders dislocation; Legg-Calves Perthes disease; Epiphyseal dysplasia; Decreased long-bone growth; OIsteopenia
Papillons
Patella luxation
Perkingese
Hypoplaisa of dense (Odontoid Process, an atlantoaxial subluxation, causes neck pain and quadriplegia); IVD (intervertebrate disk disease); Swimmers syndrome; Atypical pannus; Legg-Calves Perthes disease
Pomeranians
Patella luxation, either medial or lateral; Dwarfism; Read more [...]
Airedale Terriers
Hip dysplasia; Trembling hindquarters seen after six months of age; Thyroid disorders
American Staffordshire Terriers
Ruptured curciate ligament (very common)
Australian Terriers
Legg-Calves Perthes disease; Patella luxation
Border Terriers
Patella luxation; Hip dysplasia
Bull Terriers
None recorded in veterinary literature
Cairn Terriers
Patella luxation; Legg-Calves Perthes disease
Dandie Dinmont Terriers
IVD (intervertebrate disk disease); Achondroplasia; Patella luxation, either medial or lateral; Hip dysplasia; Shoulder luxation; Elbow dysplasia; Neoplasias
Fox Terriers (Smooth and Wire)
Shoulder dislocation; Legg Calves Perthes disease; Myasthenia gravis
Irish Terriers
Muscular dystrophy
Kerry Blue Terriers
UAP (ununited anconeal process)
Lakeland Terriers
UAP (ununited anconeal process); Legg-Calves Perthes disease;
Manchester Terriers (Standard and Toy)
Legg-Calves Perthes disease
Miniature Schnauzers
Legg-Calves Perthes disease; Muscular dystrophy
Scottish Terriers
Dwarfism; Scoottie cramp, characterized by rigidity of limbs with dog recovering in 30 seconds; Thyroid disorders; Elbow dysplasia; IVD (intervertebrate disk disease)
Sealyham Terriers
IVD (intervertebrate Read more [...]
Akitas
Juvenille polyarthrities causing incapacitating pain and fever; Hip dysplasia; Elbow dysplasia; Thyroid disorders
Alaskan Malamutes
Hip dysplasia; Chondrodysplasia, a dwarfism associated with anemia that produces stunted growth in the forelegs, lateral deviation of the foot, carpal enlargement, bowing of forelegs, and a sloping topline; Polyneuropathy, an hereditary progressive muscle weakness
Bernese Mountain Dogs
Hip dysplasia (very high incidence); Elbow dysplasia; Neoplasias
Boxers
Neoplasias; Interverterbral disk degeneration Cardiomyopathy.
Bullmastiffs
Hip dysplasia; Elbow dysplasia; Cervical vertebral malformation; UAP (ununited anconeal process)
Doberman Pinscher
Wobblers syndrome; Polyostotic fibrous dysplasia (osteophytes and cysts form in distal metaphyses of ulna and radius); Neoplasias; Elbow dysplasia
Read more [...]
Afghan Hounds
Elbow dysplasia; Malformation of articular surfaces of proximal radius and ulna; Thyroid disorders
American Foxhounds
Spinal osteochondrois (affects the ability to run)
Basenjis
Hip dysplasia
Basset Hounds
Vertebral deformity with pressure necrosis results from anomaly of third cervical vertebra; Achondroplasia (foreleg lameness caused by anatomical irregularity; cartilage of growth plate grows in irregular directions and is scant); OCD (osteochondrities dissecans) (shoulder); Osteodystrophy; Radial carpal joint irregularity; Patella luxation, medial or lateral that produces lameness at four to six months of age; IVD (intervertebrate disk disease); Panostetis
Beagles
Hip dysplasia; Epiphyseal dysplasia; IVD (intervertebrate disk disease)
Black and Tan Coonhounds
Hip dysplasia (high incidence); Polyradiculoneuritis; Coondog paralysis
Bloodhounds
Hip dysplasia; Elbow dysplasia
Borzois
Thyroid disorders
Dachshunds
IVD (intervertebrate disk disease); Osteoporosis clinically similar to swimmers, with radiographs showing dense bones and abnormal bone resorption; UAP (ununited anconeal process); Patella luxation; Achondroplasia; Thyroid disorder
English Foxhounds
Osteochondrosis Read more [...]
Brittany
Patella luxation: Hip dysplasia
Chesapeake Bay Retrievers
Hip dysplasia; Elbow dysplasia
Clumber Spaniels
Hip dysplasia
Cocker Spaniels (American)
Hip dysplasia; IVD (intervertebrate disk disease); Patella luxation, either medial or lateral; Elbow dysplasia; Thyroid disorders; Neoplasias; Anury (no tail, no caudal vertebrae); Brachury (short tail)
Curly-Coated Retrievers
Thyroid disorders; Calcium metabolic disorders; Juvenile osteoporosis.
English Cocker Spaniels
Swimmers syndrome (i.e. the inability to stand at four to six weeks of age)
English Setters
Hip dysplasia; Neoplasias
English Springer Spaniels
Hip dysplasia; Myasthenia gravis
Field Spaniels
Thyroid disorders; Hip dysplasia
Flat-Coated Retrievers
Hip dysplasia; Patella luxation; Neoplasias
German Shorthaired Pointers
Pannus; Neoplasias
German Wirehaired Pointers
Hip dysplasia; Toe fractures
Golden Retrievers
Hip dysplasia (very high incidence); Elbow dysplasia; OCD (osteochondrities dissecans) of elbow; Muscular dystrophy; Thyroid disorders; Neoplasias
Gordon Setters
Hip dysplasia; Thyroid disorders
Irish Setters
Generalized myopathy (i.e. stiff gait and other difficulties); Carpal (pastern luxation; Read more [...]
The term "balanced angulation" in general refers to the various angles of the legs, though it could include the neck angle, the angles of the head, angle of tail set, etc. According to Spira's book "Canine Terminology", balance is a synonym for symmetry. When something is symmetrical, it does not mean identical. The right and left hands are symmetrical, but, as everyone knows, the left glove will not fit the right hand. Thus, balanced angulation of the legs means that the angles of the front legs should be approximately symmetrical to the equivalent angles of the rear leg. While we can say that the rear leg angles should approximate the front leg angles, specifically, which angles are we referring to? Although I have never seen a written definition of which leg joints have equivalent angulation, it is logical to assume that the point of shoulder angle should nearly equal the angle at the stifle joint and that the angle at the elbow should nearly equal the angle at the hock joint. By present findings those dogs designed for ideal trotting should have the shoulder blade layback about 300 off the VERTICAL (not 450 degrees as commonly quoted); whereas the pelvis should be about 300 off the HORIZONTAL. Thus, these two angles Read more [...]
In my time I have read a lot of books on dogs written by people from many breeds - there is one point that has always interested me but which I have never seen positively answered. It arises in many different breeds, especially in the bull breed subgroup, and in several different ways., The point is the genetic difference between the colours red and fawn, if indeed there is a genetic difference. Old sourmug.the Bulldog is behind many breeds in which these two colours occur, perhaps not quite in. his present day form, but undoubtedly behind them an many generations ago. Now the Bulldog appears in a wide range of colours, two of which are rich deep red and pale smutty fawn - light fawn with dark tip to the hairs. He a so appears in lighter shades of red and deeper shades of fawn, with or without smart markings, sometimes so that it is not at all easy to say whether a particular dog's coat is pale red or deep fawn.
Similar
In the first example mentioned above, there is a very marked difference between the two dog's colors.. In the second one they are very similar indeed. both are recessive to brindle and probably dominant to black and tan but how ,genetically, are they related to each other?. Is the deep red dominant to Read more [...]
Breeding Great Danes Is complicated by the fact that the breed Standard condones only five colours - fawn, brindle, black, blue and harlequin - though when standardised as a recognisable breed in Germany about 100 years ago Danes appeared in many and various colours. Colour was not considered important by early breeders and a great deal of white was often present in the coat colour of fawns and brindles. The extension of white was so common that eventually German breeders disallowed the breeding of harlequins - dogs with a predorninance of white - to fawns or brindles. It's also true to say that early Danes were often referred to as being 'smokey' In colour, evidence of the recessive blue colouration being widespread. So there we have the background to the generally accepted colour Code of Ethics of today. The basic rules of breeding only fawn to fawn or brindle, brindle to brindle or fawn, black to black or blue or harlequin, blue to blue or black, harlequin to harlequin or harlequin derivates or black. By so doing, the five colours were established and stabilised. However, such matters get more complex. Without going Into all the facts of colour breeding, I would like to make the following observations.
1) One must Read more [...]
The first stage of any breeding program is selecting the dog, the second deciding which dog to mate to which. Crossbreeding is the most effective for farm livestock, but dog-breeding is greatly influenced by pedigree. In pure breeding, mating is between unrelated animals of the same breed (outbred) or with closely related animals of the same breed (inbred). It is commonly but erroneously thought that all dog breeds are highly inbred, with consequent character failings. While a purebred animal is more inbred than a crossbred, not all purebreds are highly inbred. Taking 0 per cent as a totally outbred dog and 100 per cent as purely inbred (brother sister mating for many generations), many dog breeds would have average inbreeding levels of 4-5 per cent and below. In numerically small breeds, the levels may reach 12-14 per cent, equivalent to having the same grandparent on both sides of a pedigree.
Inbreeding is a powerful tool for fixing certain features and is almost always undertaken in the establishment of breeds of any species. However, it does bring to the surface hidden defects, usually recessive, and at high levels(in excess of 0-30 per cent) can bring about serious problems usually affecting viability traits. Experiment Read more [...]
Polygenic characters tend to follow a pattern in which most individuals under study fall around the center or mean, with fewer at the two extremes. Taking wither height as an example, there are few really small animals of a particular breed and few really large ones, with most around the middle height. The number of genes which, with environmental influences, control height may he unknown, but selection can still be undertaken; many breeds have been altered or 'improved' without breeders knowing the number of genes involved.
A breeder seeking to improve or increase a particular trait must first identify those members of the breed which excel in that trait and then mate extreme examples. Progress depends on two features. One, called the selection differential, is the extent to which the selected group (parents) exceeds their population mean; the other, called the heritability, is the extent to which the character under examination is inherited in an additive fashion. If a trait is not highly inherited, even intense selection will give little response; in contrast a highly inherited trait will not be altered if minimal selection is made for it.
Most breeds have been altered over the years, some out of all recognition, Read more [...]