PRA disease
The genetic disorder, prcd-PRA, causes cells in the retina at the back of the eye to degenerate and die, even though the cells seem to develop normally early in life. The "rod" cells operate in low light levels and are the first to lose normal function. Night blindness results. Then the "cone" cells gradually lose their normal function in full light situations. Most affected dogs will eventually be blind. Typically, the clinical disease is recognized first in early adolescence or early adulthood. Since age at onset of disease varies among breeds, you should read specific information for your dog. Diagnosis of retinal disease can be difficult. Conditions that seem to be prcd-PRA might instead be another disease and might not be inherited. OptiGen's genetic test assists in making the diagnosis. It's important to remember that not all retinal disease is PRA and not all PRA is the prcd form of PRA. Annual eye exams by a veterinary ophthalmologist will build a history of eye health that will help to diagnose disease.
Unfortunately, at this time there is no treatment or cure for PRA. If your dog is affected, you may find it helpful to read about other owners' experiences living with blind dogs. (www.eyevet.org and www.blinddogs.com)
OptiGen prcd-PRA Test
Reliable identification of dogs that do not carry disease genes is the key to eliminating inherited recessive diseases, like prcd-PRA. The OptiGen prcd test for Entlebucher Mountain Dogs provides almost 100% identification of these dogs. Called "genetically clear", "noncarriers" or, more formally, "homozygous normals," such dogs pass the normal gene on to all their pups with a very high probability - which means that their pups have a very low risk of being affected with prcd. These "clear" dogs can be bred to any mate - even to a prcd-affected dog that may be a desirable breeding prospect for other reasons.
Homozygous means both copies of the gene in your dog are the SAME - both normal or both prcd. A carrier has one normal and one prcd gene.
The OptiGen prcd test is done on a small sample of blood from the dog. The test analyzes the specific DNA mutation causing prcd-PRA. The OptiGen test detects the mutant, abnormal gene copy and the normal gene copy. The result of the test is a genotype and allows separation of dogs into three groups: Normal/Clear (homozygous normal), Carrier (heterozygous) and Affected (homozygous mutant).
Prcd-PRA is inherited as a recessive trait. This means a disease gene must be inherited from each parent in order to cause disease in an offspring. Parents were either "carrier" or affected. A carrier has one disease gene and one normal gene, and is termed "heterozygous" for the disease. A normal dog has no disease gene and is termed "homozygous normal" both copies of the gene are the same. And a dog with two disease genes is termed "homozygous affected" both copies of the gene are abnormal.
It's been proven that all breeds being tested for prcd-PRA have the same disease caused by the same mutated gene. This is so, even though the disease might develop at different ages or with differing severity from one breed to another.
Although prcd-PRA is inherited, it can be avoided in future generations by testing dogs before breeding. Identification of dogs that do not carry disease genes is the key. These "clear" dogs can be bred to any mate - even to a prcd-affected dog which may be a desirable breeding prospect for other reasons. The chance of producing affected pups from such breedings depends on the certainty of test results.
Cataracts
Cataracts are presumed to be inherited although they may caused by other diseases and may occasionally be caused by trauma. They sometimes lead to blindness but in many cases they do not. A cataract is typically a partial or complete opacity, or clouding, of the lens. Cataracts may be bilateral or unilateral. If cataracts are complete and affect both eyes, blindness results. In some cases, lens replacement such as that performed on humans is possible.
The most common form of cataract found in Entles, polar, typically posterior, does not progress and is not visible to the naked eye. They, therefore, do not cause the dog any problem. The only way you know your dog has this type of cataract is to have your dog examined by a veterinary ophthalmologist.
Canine Hip Dysplasia
Canine Hip Dysplasia (CHD) afflicts millions of dogs each year and can result in debilitating orthopedic disease of the hip. Many dogs will suffer from osteoarthritis, pain and lameness, costing owners and breeders millions of dollars in veterinary care, shortened work longevity and reduced performance.The occurrence of CHD is well documented in the large and giant breed dogs, but there is also evidence that CHD is prevalent in many small and toy breeds as well as in cats.
Hip dysplasia was first described in 1937. It is a disease of complex inheritance. Accordingly, veterinarians and dog breeders have attempted to eliminate CHD through selective breeding strategies. However, the reduction of CHD frequency in pure-breed dogs has been disappointing.
PennHIP testing
In 1983, Dr. Gail Smith from the University of Pennsylvania School of Veterinary Medicine conceived and developed a new scientific method for the early diagnosis of CHD. Research conducted in his laboratory proved the diagnostic method to be capable of estimating the susceptibility for CHD in dogs as young as sixteen weeks of age. In 1993, Dr. Smith established PennHIP, a cooperative scientific initiative, to serve as a multi-center clinical trial of the new hip dysplasia diagnostic technology. The program was successful and quickly grew beyond the capacity and purpose of a university research laboratory. Initially, the University of Pennsylvania licensed PennHIP to outside biotech companies in order to make the technology available for widespread public use and to allow Dr. Smith and his colleagues to continue their research at the School of Veterinary Medicine. PennHIP has recently been reacquired by the University of Pennsylvania and is now a not-for-profit organization.
PennHIP is a multifaceted radiographic technology (x-ray) for hip evaluation. The technique assesses the quality of the canine hip and quantitatively measures canine hip joint laxity. The PennHIP method of evaluation is more accurate than the current standard in its ability to predict the onset of osteoarthritis. Osteoarthritis, also known as degenerative joint disease (DJD), is the hallmark of canine hip dysplasia (CHD).
PennHIP is more than just a radiographic technique. It is also a network of veterinarians trained to perform the PennHIP methodology properly and, perhaps most importantly, it is a large scientific database that houses the PennHIP data. The radiographs are made by certified PennHIP members worldwide and are sent to the PennHIP analysis center for evaluation. The resulting data is stored in the database, which is continually monitored as it expands. As more information becomes available, the PennHIP laboratory is able to obtain more precise answers to questions about the etiology (cause), prediction and genetic basis of CHD.
PennHIP has studied the efficacy of this method from the eight weeks up to three years of age. The PennHIP method can be reliably performed on a dog as young as 16 weeks old. Passive hip laxity at 16 weeks correlates highly with later hip laxity. In other words, a dog's hip laxity at 16 weeks will be much the same at one year, two years or even three years. The accuracy of laxity measurements for German Shepherd Dogs less than 16 weeks of age is not high enough to be of clinical use. Other breeds require study to determine the earliest reliable age of evaluation.
The looser the joint, as determined by the PennHIP method, the greater is the chance that the hip will develop DJD. (The standard hip-extended method can actually mask true hip joint laxity). There are obvious advantages to screening dogs for hip joint laxity at 4 months of age (or six months, 1 year, etc.) as opposed to waiting until 2 years of age. The reliability of the PennHIP method slightly improves with age, with one year 1 year being marginally superior to 6 months, which in turn is marginally better than 4 months. For all dogs, we recommend when possible, to use the mean (average) of repeated evaluations to get a more reliable estimate of a dog's hip laxity status (phenotype).
PennHIP testing is gaining popularity due to the early age of testing. Although the test can be administered as early as 6 weeks, most agree to wait until after six months of age, to lower the risk of anesthetic complications.
EUS - Entlebucher Urinary Syndrome
Very little is know, or published about EUS. In fact, we requested permission to reproduce some of the information, and were denied.
It often does not have any warning symptons, and puppies with EUS often lead normal lives without EUS being diagnosed. Rare cases may require surgery to correct. EUS is characterized by abnormalities in the urinary tract which can include ureteral ectopia, uterial obstruction, hydroureter, and hydronephrosis. Ureteral ectopia is the least sever of these abnormalities, and is common in many canine breeds. Further research is being conducted by Michigan State University.
Signs of EUS are usually evident early in a Entle's life.
These may include:
• drinking abnormally large quantities of water
• accidental urine leakage, possibly when asleep or tired
• persistant bladder infections that don't respond well to antibiotic
• a symptom that requires immediate attention is sudden onset of vomiting
Having these symptoms does NOT mean your Entle has EUS. It simply means you should have your Veterinarian do further testing.
As conscientious Entle owners and breeders, we feel it is important to make you aware of a condition that has been affiliated with the breed. However, with no known diagnostic path, limited symptoms and even fewer diagnosis, we feel confident to wait for the publication of the research information.
