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... HEALTH ...
Sheltie is basically a healthy dog breed, but is really important to know how kind of genetically test must your sheltie have to be sure about his health...
COLLIE EYE ANOMALY (CEA)
The eye is a complicated thing. In order to absorb light and receive an adequate blood supply, the eye needs help from the choroid, a collection of blood vessels within a layer of tissue located under the retina.
When this part of the eye doesn’t develop the right way in dogs, it can lead to Collie Eye Anomaly (CEA) – a genetic disease that affects Collies as well as other dog breeds. Also known as Choroidal Hypoplasia, this condition can lead to vision loss.
CEA is a genetic condition must be tested, if the sheltie is:
§ Normal: sheltie is healthy and does not carry the disease
§ Carrier: sheltie is healthy but bears the disease
§Affected: sheltie have the disease and bears the disease
MULTI-DRUG RESISTANCE GENE (MDR1)
Multi-Drug Resistance Gene (MDR) codes for a protein that is responsible for protecting the brain by transporting potentially harmful chemicals away. In certain breeds, a mutation occurs in the MDR1 gene that causes sensitivity to Ivermectin, Loperamide, and a number of other common drugs. Dogs with this mutation have a defect in the P-glycoprotein that is normally responsible for transporting certain drugs out of the brain. The defective protein inhibits the dog's ability to remove certain drugs from the brain, leading to a buildup of these toxins. As a result of the accumulation of toxins, the dog can show neurological symptoms, such as seizures, ataxia, or even death.
Dogs that are homozygous for the MDR1 gene (meaning that they have two copies of the mutation) will display a sensitivity to Ivermectin and other similiar drugs. These dogs will also always pass one copy of the mutation to all potential offspring. Dogs that are heterozygous (meaning they have only one copy of the mutation) can still react to these drugs at higher doses. Also, there is a 50% chance that a dog with one copy of the mutation will pass it on to any offspring.
There are many different types of drugs that have been reported to cause problems. The following is a list of some of the drugs:
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Ivermectin (found in heartworm medications)
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Loperamide (Imodium over the counter antidiarrheal agent)
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Doxorubicin
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Vincristine
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Vinblastine (anticancer agents)
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Cyclosporin (immunosuppressive agent)
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Digoxin (heart drug)
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Acepromazine (tranquiliser)
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Butorphanol ("Bute" pain control)
The following drugs may also cause problems:
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Ondansetron
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Domperidone
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Paclitaxel
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Mitoxantrone
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Etoposide
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Rifampicin
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Quinidine
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Morphine
MDR1 is a genetic condition must be tested, if the sheltie is:
§ -/- Affected: the dog carries two copies of the mutant gene and is homozygous for the MDR1 mutation. The dog will react to Ivermectin, or other listed drugs, and will always pass a copy of the mutated gene to its offspring.
§ +/- Carrier: both the normal and mutant copies of the gene detected. Dog is a carrier for the MDR1 mutation, and can pass on a copy of the defective gene to its offspring 50% 0f the time.
§ +/+ Clear: dog tested negative for the MDR gene mutation, and will not pass on the defective gene to its offspring.
VON WILLEBRAND'S DISEASE (vWd)
Von Willebrand’s Disease (vWd) is an inherited bleeding disorder, similar to hemophilia. It is a complex and difficult disorder to deal with, because genetics, diagnostic abnormalities, pathogenic mechanisms, and sometimes conflicting clinical signs are all involved.
It comes in 3 major types, but only two affect Shelties, Type I and Type III.
Type I is a mild bleeding disorder with the risk coming mostly from trauma or surgery. (This form of the disease is rarely found in Shelties.)
Type III is a severe bleeding disorder that results in a high risk of bleeding from something as simple as a nail cut too short to the risk of serious bleeding due to trauma or surgery. Sadly, Type III is the most common type found in Shelties.
The commonality between all vWD is a reduction in the amount or function of von Willebrand factor (vWF), which is manifested through abnormal platelet function and prolonged bleeding. The vWF factor is a blood protein which binds platelets to blood vessels when they are injured. Absence or deficiency of the factor can, therefore, lead to uncontrolled bleeding episodes.
Von Willebrand disease is a genetic condition must be tested, if the sheltie is:
§ Clear: does not have the disease and can not pass on the defective gene for the disease.
§ Carrier: does not have the disease but can pass on the defective gene for the disease.
§ Affected: has the disease and passes on the defective gene for the disease.
DERMATOMYOSITIS
Dermatomyositis is an inherited inflammatory disease of the skin, muscles, and blood vessels. It typically develops in young collies, Shetland sheepdogs, and their crossbreeds.
Studies suggest that dermatomyositis is inherited in an autosomal dominant manner (the chromosome is inherited from both parents), with variable expression. Skin lesions typically develop before six months of age, and may develop as early as seven weeks. The full extent of lesions usually is present by one year of age, with lessening afflictions thereafter.
Signs of dermatomyositis can vary from subtle skin lesions and inflammation of muscles, to severe skin lesions and a generalized decrease in muscle mass (known as muscle atrophy), with an enlarged esophagus (the tube running from the throat to the stomach). Skin lesions around the eyes, lips, face, and inner surface of the prick ears will vary in intensity; the entire face may be involved. The tip of the tail and bony prominences can also be affected.
Causes for dermatomyositis can usually be traced to a hereditary source, but can also be sourced to an immune-mediated disease, or to infectious agents.
MIELOPATY DEGENERATIVE (DM)
Canine Degenerative Myelopathy (DM) has been recognized for more than 35 years as a spontaneously occurring spinal cord disorder in older dogs, with age of onset ranging between 8 and 14 years.
Degenerative Myelopathy is characterized by a gradual degeneration of spinal reflexes and muscle weakness. The initial signs of DM typically include loss of coordination (asymmetric ataxia) in the hind limbs. The symptoms worsen with time when the affected dog can no longer support its weight in the hind limbs. The age of onset and the speed of disease progression is variable. Affected small breed dogs often develop DM at an older age and deteriorate more slowly than affected dogs of large breeds.
DM disease is a genetic condition must be tested, if the sheltie is:
§ Normal: this dog has two copies of the normal gene and is likely to be free of the DM disease.
§ Carrier: this dog has one copy of the mutation and one copy of the normal gene. The chance dog will develop the disease are low.
§ Affected: this dog has two copies of the mutated SOD1 gene and has a high risk of developing the disease during its lifetime.
HIPS DYSPLASIA (HD)
The hip joint is composed of the ball and the socket. The development of hip dysplasia is determined by an interaction of genetic and environmental factors, though there is a complicated pattern of inheritance for this disorder, with multiple genes involved. Hip dysplasia is the failure of the hip joints to develop normally (known as malformation), gradually deteriorating and leading to loss of function of the hip joints.
Hip dysplasia is one of the most common skeletal diseases seen in dogs.
Hip dysplasia often begins while a dog is still young and physically immature. Early onset usually develops after four months of age.
There is no genetic test, the only possibility is to make preventive plates on puppies that have around 5 months.
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