Genetic Disorders
Found [146] Articles :: Page 9 of 10
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Protein Losing Enteropathy, also known more simply as PLE, is one of the most challenging of the metabolic disease to diagnose and understand. PLE occurs in many different breeds but is more common in the Soft Coated Wheaten Terrier, Yorkshire Terrier and the Basenji breeds. The condition is more common in small to medium breeds of dogs and is becoming more common in toy breeds. Both males and females are typically equally diagnosed and the condition can occur at any age. Often the symptoms are rather subtle and may simply be noted by the owner as a constant or chronic problem with diarrhea for the dog. In severe cases excessive weight loss and even swelling in the abdominal cavity can occur since the protein content of the body is so depleted that typical metabolic activity can occur. Once swelling or edema occurs in the chest, breathing will become labored and problematic and the dog may refuse to eat or want to exercise or move about. Lack of energy, fatigue and constant inactivity is considered to be the most common symptom noted in both advanced and early stages of the disease. [...]
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Like Protein Losing Enteropathy, which is a protein and plasma losing disease of the gastrointestinal system, protein losing nephropathy allows protein and plasma to be lost from the kidneys. The medical term for protein losing nephropathy is glomerulopathies, which covers the entire range of protein losing conditions of the kidneys. Over time this condition results in a lack of protein to fuel the body, resulting in a shutdown of the metabolic processes, build of up fluid in the abdomen and chest cavities, and eventual death from complications with edema if not treated. With the kidneys affected the eventual result of the disease is renal failure, which is fatal in dogs. Typically PLN is seen in the same breeds that are affected by PLE, however PLN is more common in females than males and can often occur in dogs that are between the ages of two to six years. Breeds that are more predisposed to the condition include Samoyeds, Soft-coated Wheaten Terriers, Bernese Mountain Dogs, Rottweilers, Beagles, Dobermans and Greyhounds. [...]
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Anterior Segment Dysgenesis, more simply known as ASD, is an inherited, genetic condition that most often occurs in horses that are dark or chocolate brown in color and have a white or cream colored mane and tail. Typically horses with ASD are part of the Rocky Mountain Horse breed, which is the gaited horses bred and developed in the Rocky Mountain area of the United States.
ASD is present at birth and does not become progressively worse with age; rather it remains constant throughout the life of the horse. Screening by a veterinary ophthalmologist when the foal is approximately four months old can confirm the presence or absence of the condition, and foals can then be cleared for breeding stock if the problem is not present at that age. Horses cannot develop ASD as they mature so it is relatively easy to keep affected foals from being produced if owners are diligent with testing before breeding. [...]
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Equine CA or Cerebellar Abiotrophy, found almost solely in the Arabian horse bloodlines, is a neurological, genetic condition. Most foals appear normal and show no sign of cerebellar abiotrophy at birth but noticeable symptoms usually appear around four months of age. There are some cases where the first symptoms of cerebellar abiotrophy appeared in foals only a few days old or horses over a year.
Cerebellar abiotrophy develops when the neurons recognized as Purkinje cells, located in a region of the brain called the cerebellum, start to die off shortly after birth. It affects a horse's coordination and balance under six months of age but because of the gradual onset of CA symptoms, caretakers or owners often do not notice any physical problems in affected horses until they are much older. A horse without Purkinje cells has no sense of distance and space. [...]
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Club foot is a lack of the attachment of the coffin bone in the hoof that results in varying degrees of malformation of the hoof as well as the stride of the affected horse. Club foot is almost always on one of the front feet, but very rarely on both. About a fifth of the time club foot may be seen on a hind foot, but typically these cases are much less severe.
The coffin bone in the horse's hoof is responsible for giving the exterior hoof its uniform shape, as well as allowing the horse to carry its weight normally distributed throughout movement. The coffin bone is actually in three separate segments, and club foot is noted when the lowest segment, or third phalange, is twisted and out of proper positioning. [...]
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Although congenital hepatic fibrosis is more commonly seen in other species of mammals including humans, it is occasionally seen in one breed of horses, and that is the Swiss Freiberger horse. In research tests, all of the reported cases of congenital hepatic fibrosis within the breed can be directly linked back to offspring and decedents of one stallion named Wigar, thereby confirming that the condition is hereditary. Since the condition does not occur in every foal born in the line, researches have determined that it is a recessive autosomal gene that causes the condition.
Congenital hepatic fibrosis is present at birth and results in a thickening and altering of the tissues of the liver. Typically in most affected horses the condition is progressive, fatal and non-treatable with the liver enlarging significantly and large cysts developing throughout the organ. Since the liver is responsible for filtering and detoxifying the blood, when a malfunction in the liver occurs the results are very serious and usually fatal. [...]
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Cow hock is a term used to describe a particular formation or conformation of the hindquarters of a horse. The hock is the joint that is between the cannon bone and the gaskin on the hind leg, it is the point at which the leg bends towards the back before it drops straight down to the fetlock. The hock is roughly equivalent to a human elbow in that it bends forward rather than backwards like our knees do.
The term cow hock simply means that the horse's hocks turn in towards each other rather than staying parallel. If you look at a cow you will notice that their hocks turn in, hence the name. Many breeders prefer a horse to be very slightly cow hocked, especially in gaited breeds where it adds a somewhat rolling movement to the hindquarters. Most horses will have a slight turning in at the point of the hock, which will cause no soundness problems nor will it affect the horse's performance in any way. [...]
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Cryptorchidism occurs when one or both of the testicles in a colt do not descend into the scrotum. This condition can occur in the male of any species, but it is often noted in specific lines of horses, so it is likely to have a genetic or inherited component. When a colt's testicle or testicles do not descend the colts is called a ridgling or rig, or may also be known as a high flanker if the testicle is located just above the scrotum under the skin.
In all male fetuses the testicles are first developed in the abdominal cavity, then at about the second week of development they move down through the inguinal canal, through two sets of inguinal rings, into the scrotum. The rings are muscular areas that help to move the testicles down into the scrotum. In some male fetuses, through hormonal, mechanical and developmental reasons either one or both of the testicles do not move into the correct location. [...]
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Just like any type of mammal, the horse depends on the spine and skeleton to support the body, and the spinal chord and the brain to send impulses through the skeleton and muscles to move. In conditions that are known as degenerative disorders there are either toxins, injuries, infections, genetic conditions or other forms of diseases that cause the natural functioning of the skeleton or nervous systems to degenerate or break down over time. Once these conditions are present, unless noticed and treated very early on there is likely to be permanent and non-reversable damage that will affect the horse throughout his or her life, even if the condition is managed. [...]
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Many people incorrectly think that Miniature Horses and the Falabella breed are actually dwarf horses, which is false. Miniature horses and Falabellas are bred to be small and through selective breeding have developed into their own breeds that breed true to small, usually well-conformed horses. However, it is true that dwarf horses have been used in the development of the Miniature Horses bred by disreputable breeders resulting in a greater likelihood of dwarf offspring from Miniature Horses. This short cut to developing the smallest possible Miniature Horses has had disastrous results. Falabella horses, only being bred by one family, have had fewer problems with dwarfism as the breeding herd was comprehensively managed. Full sized or "normal sized" horses of any breed will very rarely produce a dwarf offspring, but this is extremely uncommon. Some pony breeds, especially in remote areas of the world where the breeds have been very isolated and have inbred continually, dwarfism is a serious concern to the continuation of the breed. [...]
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Dyscoria is a distortion or irregular development of the pupil of the eye that leads to vision problems as the pupil may not dilate and expand correctly in changing light environments. In horses dyscoria is most commonly noted in breeds that are part of the gaited horses bred in the Rocky Mountain areas of the United States. These breeds include the Rocky Mountain Pleasure Horse, Kentucky Mountain and crosses between these breeds. This condition can also be found in dogs and humans.
Most horses with dyscoria also have an eye condition known as ASD or anterior segment dysgenesis. This condition causes an irregular formation of the front parts of the eye that is genetically linked but often not serious. It is not progressive and does not become more pronounced as the horse matures, in fact many horses have such mild symptoms of the condition that it is not known unless an ophthalmologic examination is completed by a vet. Diagnosis of dyscoria is done by applying drops of mydriatic drug that causes normal pupils to dilate. The pupil with dyscoria will not dilate normally and will confirm diagnosis of the condition. [...]
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Most commonly associated with Quarter horse bloodlines, EPSM or Equine Polysaccharide Storage Myopathy is a muscle condition or disease. There are documented occurrences of EPSM in other horses such as American Paint horses, Warm bloods, draft horses, quarter horse crosses, and draft crosses. Evidence shows that in Quarter horses, EPSM is a inheritable disease, but this remains unproven in many other breeds. A horse with Equine Polysaccharide Storage Myopathy has an excessive glycogen buildup or storage in the skeletal muscles due to improper digestion of sugars, starches and carbohydrates found in cereal grains such as barley, corn, and oats.
Often, there are very few or very subtle symptoms in the early stages and because of the recent discovery of EPSM, it is often not considered or diagnosed until fairly advanced. [...]
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As with many of the hardest to eradicate genetic conditions Fell Pony Syndrome is linked to an autosomal recessive gene. This means that the condition will only occur if both the dam and the sire have the gene but are only carrying one, not two copies. When the two mate, each contributes one half of the double gene needed, and if both contribute the recessive gene for the syndrome the result is a foal that will only live a few short weeks before dying.
Autosomal means that there is one, two-part gene that is responsible for the condition. The foal will inherit one part of the gene from the mother and one part from the father to make the complete gene pair. Since foals with the condition will die and not reproduce, only carriers, adults that have one Fell Pony Syndrome gene and one normal gene, or clear, adults with two normal genes, will continue on in the population. Since horses with only one gene have no visible symptoms of carrying the gene, they can only be detected through careful monitoring and recording of breedings that produce either healthy or unhealthy foals. [...]
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Lavender foal syndrome or LFS is a newly classified genetic condition that exists in the Arabian horse breed. It is caused by an autosomal recessive gene, which means that it is directly inherited from each of the parents. Both the sire and dam must have the recessive gene for LFS and must pass it to the foal in order for the foal to have the defect. A horse, either male or female, that has only one copy of the gene for LFS will not exhibit any signs or problems throughout their life, it will only be their foal, if they are crossed with another LFS recessive horse that will have the risk of being born with the syndrome.
The most telling diagnosis of LFS is the unique color of the foal. He or she will be born with a lavender, silver or pinkish tinge to the coat that is different from a gray or roan coloration, it is very abnormal in color. The eyes may also be somewhat bluish to gray in color, but this is often not as noticeable. The mare will usually have troubles during the delivery of the foal and the foal will be unable to stand or move his or her legs. [...]
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As with any animal the horse's liver plays a key role in detoxifying the blood, regulating parts of the metabolic process, as well as storage of nutrients and synthesis of essential chemicals and proteins in the body. The liver is also very important in producing bile, which is necessary for proper digestion.
Liver diseases and disorders can occur due to injury, infections, disease, genetic conditions or even toxicity. Depending on the decrease in functioning of the liver the clinical signs of liver problems can range from a jaundiced or yellow appearance to the whites of the eyes to severe causes resulting in rapid death. In mild to moderate cases there will also be colic or digestive problems, swelling of the abdominal area and weight loss, and even central nervous system problems such as staggering, lack of coordination and muscle weakness due to a condition known as hepatic encephalopathy. Depending on the type of onset of the condition these symptoms may be very sudden or may develop slowly over time. [...]
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Genetic Disorders
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