Overview of Hereditary Diseases

MDR1 multi-drug-sensitivity

 

It is well known that Collies and related breeds can have adverse reactions to drugs such as ivermectin, loperamide (Imodium®), and others. The problem is due to a mutation in the multi-drug resistance gene (MDR1). This gene encodes a protein, P-glycoprotein, that is responsible for pumping many drugs and other toxins out of the brain. Dogs with the mutant gene can not pump some drugs out of the brain as a normal dog would, which may result in abnormal neurologic signs. The result may be an illness requiring an extended hospital stay--or even death. It is very important to know, whether your dog is affected, or not. Tests are available worldwide.
For more information look here: http://www.vetmed.wsu.edu/depts-VCPL/#Drugs

 

 

Grey Collie Syndrome GCS

 

Canine Cyclic Neutropenia is a stem cell disorder that occurs in gray collies. Puppies are usually smaller and weaker than their littermates and by 8 to 12 weeks of age they develop clinical signs such as fever, diarrhea, joint pain, or other signs associated with eye, respiratory, or skin infections.
The disorder is caused by an abnormality of the stem cells in the bone marrow, from which all blood cells are developed. The result is a cyclic fluctuatian in blood cell numbers. Every 10 to 12 days the number of neutrophils drops dramatically, and then rebounds. There is an increased susceptibility to infection corresponding to the dip in neutrophil numbers. Affected dogs are subject to severe recurring bacterial infections, primarily of the respiratory or gastrointestinal tract. These dogs are also prone to bleeding episodes due to the drop in blood cells numbers. This is a serious genetic disorder. Even with the best of care, affected dogs rarely live beyond 2 or 3 years of age.
The disease occurs in all gray (not merle) collies. Affected puppies have a silver gray hair coat, sometimes with a slight yellowing due to a mixture of light beige and light gray hair.

  

 

CEA- Collie Eye Anomaly

 
Collies share Collie Eye Anomaly (CEA) with several other breeds – it’s not just a problem for collies. CEA is more technically known as Choroidal Hypoplasia (CH). It is a recessively inherited eye disorder that causes abnormal development of the choroid - an important layer of tissue under the retina of the eye. This disease is seen most frequently in U.S. collies, but also worldwide in Rough and Smooth Collies, Border Collies, Australian Shepherds, Lancashire Heelers, and Shetland Sheepdogs. Since the choroid layer does not develop normally from the start, the primary abnormality can be diagnosed at a very young age. Regrettably, there is no treatment or cure for CEA.

The primary problem is choroidal hypoplasia (CH). There is under-development (hypoplasia) of the eye tissue layer called the choroid. The choroid appears pale and thin, almost transparent, and the blood vessels of the choroid can easily be recognized in those “thin” areas. The ophthalmologist, looking at the back of the eye (the fundus) with an ophthalmoscope, typically will see an area of choroidal thinning that appears like a “window” to the underlying vessels and sclera.

MILD disease: Mild disease is very common in U.S. collies and is present in the other breeds named above. It is easily recognizable on careful ophthalmologic examination as early as 5 to 8 weeks of age. The lesion appears as an area lateral (temporal) to the optic disc with reduction or absence of pigment so that the underlying vessels of the choroid are seen. The choroidal vessels may be reduced in number and of abnormal shape. The underlying white sclera might also be visible. Once the retina changes to its adult color around 3 months of age, the normal pigment sometimes masks the changes in the choroid (so-called “go normal”). In mildly affected dogs, choroidal thinning is the only detectable abnormality and the dog retains normal vision throughout life. However, dogs with mild disease can produce severely affected offspring.

SEVERE disease: In severely affected dogs, approximately 25% of dogs with CEA/CH, there are related problems with the health of the eye that can result in serious vision loss in some cases. Colobomas are seen at and near the optic nerve head as outpouchings or “pits” in the eye tissue layers. Colobomas can lead to secondary complications such as partial or complete retinal detachments and/or growth of new but abnormal blood vessels with hemorrhage – bleeding inside the eye. This happens in 5-10% of dogs with CEA/CH, generally by 2 years of age, and can affect either one or both eyes. Complications of severe disease can lead to vision loss, although this disorder only rarely threatens total blindness.

CEA/CH is not progressive in the usual sense. The essential features, choroidal hypoplasia and coloboma, are congenital – the abnormalities develop as the eye develops. These features are also stationary once ocular development is complete around 8-12 weeks of life. Retinal detachments and/or aberrant vessel formation can be congenital or develop later, in general only in eyes with colobomas.
 

Progressive Retinal Atrophy PRA

There are two different types of PRA recognised: generalised PRA (also known simply as PRA) and central PRA (now known as Retinal Pigment Epithelial Dystrophy - RPED). Both diseases are inherited and both may be seen in the same breed. PRA causes a night-blindness progressing to total blindness. Secondary cataracts are common. There is no treatment for this disease. RPED causes poor vision in bright light. Dogs with this condition may bump into stationary objects. Animals are normally affected in both eyes and loss of vision is progressive. Clinical signs usually appear between 2-6 years of age. Some dogs will retain partial vision while others will become blind. Vitamin E supplementation may help in early stages of the disease. 
 

Hereditary Cataract KAT

 

A cataract is an opacity of the lens or lens capsule. It is seen as a cloudiness of the eye. Hereditary cataracts are seen in puppies once their eyes have opened. Primary cataracts are not associated with any other abnormality in the eye. Secondary cataracts are seen with other hereditary diseases (e.g. PRA, lens luxation).

 

Hip Dysplasia HD


This is a very common condition which affects most medium to giant breeds. It first manifests itself between 4 and 12 months. It is a hereditary disease and can also caused by wrong feeding and too much activity of the dog in its youth.
Affected puppies will show a range of signs. They may have difficulty getting up in the morning, going up and down stairs, they may have clicking hips. A characteristic 'bunny hopping' gait when running may also be seen. Some animals will show no signs at all and their abnormalities will only be seen on X-rays.
To diagnose this condition, your vet will want to X-ray your dog's hips. This will require sedation or a general anaesthetic. The vet will also want to test your dog's range of motion, which will probably also be done under sedation.
If your dog is diagnosed with hip dysplasia, there are various treatment options and your vet will advise you as to the best option for your pet. In some cases, surgery may be required.

 

Canine Epilepsy

 

Canine Epilepsy is a chronic condition characterized by recurrent seizures.  Although seizures are always abnormal events, not all seizures in dogs are caused by canine epilepsy.

Canine Epilepsy is a disorder of the brain where abnormal electrical activity triggers further uncoordinated nerve transmission.  This uncoordinated and haphazard nerve tissue activity scrambles messages to the muscles of your dog's body and the coordinated use of the muscles is then inhibited. 

Because there are many causes of chronic recurrent seizures in dogs, canine epilepsy is not a specific disease or even a single syndrome, but rather a diverse category of disorders.  Canine Epilepsy is broadly divided into idiopathic and symptomatic disorders.  Idiopathic Epilepsy, also called primary epilepsy, means that there is no identifiable brain abnormality other than seizures.  Symptomatic epilepsy (also called secondary epilepsy) is seizures that are the consequence of an identifiable lesion or other specific cause.    

Most dogs with idiopathic epilepsy suffer their first seizure between the ages of one and five years of age.  A genetic basis for idiopathic epilepsy is strongly suspected in several breeds including the Beagle, Belgian Tervuren, Keeshond, Dachshund, British Alsatian, Labrador Retriever, Golden Retriever and Collie.  Idiopathic canine epilepsy may have an inherited basis in other breeds also.

Autoimmune Diseases

 

Known autoimmune diseases in Collies and Shelties are f.e. Dermatomyositis, Lupus  Erythematosis and Collie Nose. They all cause lesions of the skin, sometimes a stiff gait or shifting lameness. Other signs may include a hemolytic anemia or thrombocytopenia, leukopenia or a symmetrical dermatitis, especially over the bridge of the nose ("butterfly lesion,").

Diagnosis is often difficult, especially for the general practitioner who may see one or two cases during a career. Skin biopsy and immunofluorescent staining are generally required to diagnose one of these diseases, and the prognosis for recovery may vary. Corticosteroids are the primary mode of therapy.