Papillon Health

This is a very brief overview of genetic diseases affecting the Papillon

If you're looking for a Papillon puppy, it is very important to find a reputable Papillon Breeder who has the health concerns of the breed at the heart of their breeding program. It is only by testing and clearing breeding stock that the problems that plaque the breed can be brought under control. While this doesn't guarantee a perfect puppy, it does help in knowing that you and the breeder have done the what you can to find a healthy puppy. Some people who breed are ignorant, or don't care about your puppy's health. Here at PlayTyme Papillons it is at the very heart of everything we do.

This is just a very brief overview of some of the problems with Papillons. I believe in being up-front and honest because I have a deep love for this breed and responsible breeding is imperative if we are to have victory over some of these issues. It is a devastating, costly and painful process to see a dog needlessly suffer from any one of these issues.  Genetic testing is crucial in any breeding program that is dedicated to the protection of the breed.

The initial investment of a healthy puppy from a reputable breeder who values genetic testing could save you thousands of dollars in veterinary costs and medical treatments.

Papillons currently need the following tests done according to the Papillon club of America prior to being bred to make sure they are healthy and sound.

Eye Examination by a boarded ACVO Ophthalmologist- recommend screening every 2 years


OFA Patellar Luxation -OFA Evaluation - minimum age 12 months

Cardiac Evaluation

Congenital Cardiac Exam - minimum age 12 months - OR
Advanced Cardiac Exam

Visit the official club website

http://www.papillonclub.org

Papillon Club also recommends DNA testing of 

DNA DISEASES:

• cone-rod Dystrophy 1 PRA
• Factor VII deficiency
• Neuroaxonal Dystrophy- Papillon type
• Progress Retinal Atrophy PRA1 - Papillon type
• von Willebrands disease type 1

 

++++++++++++++++++++++++++++++++++++++++++++++++++

What is Patellar Luxation?

The patella, or kneecap, is part of the stifle joint (knee). In patellar luxation, the kneecap luxates, or pops out of place, either in a medial or lateral position.
Bilateral involvement is most common, but unilateral is not uncommon. Animals can be affected by the time they are eight weeks of age. The most notable finding is a knock-knee (genu valgum) stance. The patella is usually reducible, and laxity of the medial collateral ligament may be evident. The medial retinacular tissues of the stifle joint are often thickened, and the foot can be seen to twist laterally as weight is placed on the limb.
Patellar luxations fall into several categories:

Medial luxation (toy, miniature, and large breeds)
Lateral luxation (toy and miniature breeds)
Lateral luxation (large and giant breeds)
Luxation resulting from trauma (various breeds, of no importance to the certification process)

Numbers 1-3 are either known to be heritable or strongly suspected.
Medial Luxation in Toy, Miniature, and Large Breeds

Although the luxation may not be present at birth, the anatomical deformities that cause these luxations are present at that time and are responsible for subsequent recurrent patellar luxation. Patellar luxation should be considered an inherited disease.
Clinical Signs

Three classes of patients are identifiable:

Neonates and older puppies often show clinical signs of abnormal hind-leg carriage and function from the time they start walking; these present grades 3 and 4 generally.
Young to mature animals with grade 2 to 3 luxations usually have exhibited abnormal or intermittently abnormal gaits all their lives but are presented when the problem symptomatically worsens.
Older animals with grade 1 and 2 luxations may exhibit sudden signs of lameness because of further breakdown of soft tissues as result of minor trauma or because of worsening of degenerative joint disease pain.

Signs vary dramatically with the degree of luxation. In grades 1 and 2, lameness is evident only when the patella is in the luxated position. The leg is carried with the stifle joint flexed but may be touched to the ground every third or fourth step at fast gaits. Grade 3 and 4 animals exhibit a crouching, bowlegged stance (genu varum) with the feet turned inward and with most of the weight transferred to the front legs.

Permanent luxation renders the quadriceps ineffective in extending the stifle. Extension of the stifle will allow reduction of the luxation in grades 1 and 2. Pain is present in some cases, especially when chondromalacia of the patella and femoral condyle is present. Most animals, however, seem to show little irritation upon palpation.
Lateral Luxation in Toy and Miniature Breeds

Lateral luxation in small breeds is most often seen late in the animal’s life, from 5 to 8 years of age. The heritability is unknown. Skeletal abnormalities are relatively minor in this syndrome, which seems to represent a breakdown in soft tissue in response to, as yet, obscure skeletal derangement. Thus, most lateral luxations are grades 1 and 2, and the bony changes are similar but mirrored to those described for medial luxation. The dog has more functional disability with lateral luxation than with medial luxation.
Clinical Signs

In mature animals, signs may develop rapidly and may be associated with minor trauma or strenuous activity. A knock-knee or genu valgum stance, sometimes described as seal-like, is characteristic. Sudden bilateral luxation may render the animal unable to stand and so simulate neurological disease. Physical examination is as described for medial luxation.
Lateral Luxation in Large and Giant Breeds

Also called genu valgum, this condition is usually seen in the large and giant breeds. A genetic pattern has been noted, with Great Danes, St. Bernards, and Irish Wolfhounds being the most commonly affected. Components of hip dysplasia, such as coxa valga (increased angle of inclination of the femoral neck) and increased anteversion of the femoral neck, are related to lateral patellar luxation. These deformities cause internal rotation of the femur with lateral torsion and valgus deformity of the distal femur, which displaces the quadriceps mechanism and patella laterally.
Clinical Signs

Bilateral involvement is most common. Animals appear to be affected by the time they are 5 to 6 months of age. The most notable finding is a knock-knee (genu valgum) stance. The patella is usually reducible, and laxity of the medial collateral ligament may be evident. The medial retinacular tissues of the stifle joint are often thickened, and the foot can often be seen to twist laterally as weight is placed on the limb.
Patellar Luxation Grades

The Patellar Luxation Database is for dogs 12 months and over. Examinations performed on dogs less than 12 months will be treated as consultations and no OFA numbers will be assigned.

A method of classifying the degree of luxation and bony deformity is useful for diagnosis and can be applied to either medial or lateral luxations by reversing the medial-lateral directional references. The position of the patella can easily be palpated starting at the tibial tubercle and working proximally along the patellar ligament to the patella.

Grade 1: Manually the patella easily luxates at full extension of the stifle joint, but returns to the trochlea when released. No crepitation is apparent. The medial, or very occasionally, lateral deviation of the tibial crest (with lateral luxation of the patella) is only minimal, and there is a very slight rotation of the tibia. Flexion and extension of the stifle are in a straight line with no abduction of the hock.
Grade 2: There is frequent patellar luxation, which, in some cases, becomes more or less permanent. The limb is sometimes carried, although weight bearing routinely occurs with the stifle remaining slightly flexed. Especially under anesthesia, it is often possible to reduce the luxation by manually turning the tibia laterally, but the patella reluxates with ease when manual tension of the joint is released. As much as 30 degrees of medial tibial torsion and a slight medial deviation of the tibial crest may exist. When the patella is resting medially the hock is slightly abducted. If the condition is bilateral, more weight is shifted onto the forelimbs. Many dogs with this grade live with the condition reasonably well for many years, but the constant luxation of the patella over the medial trochlear ridge of the trochlea causes erosion of the articulating surface of the patella and also the proximal area of the medial lip. This results in crepitation becoming apparent when the patella is luxated manually.
Grade 3: The patella is permanently luxated with torsion of the tibia and deviation of the tibial crest of between 30 degrees and 50 degrees from the cranial/caudal plane. Although the luxation is not intermittent, many animals use the limb with the stifle held in a semi-flexed position. The trochlea is very shallow or even flattened.
Grade 4: The tibia is medially twisted and the tibial crest may show further deviation medially with the result that it lies 50 degrees to 90 degrees from the cranial/caudal plane. The patella is permanently luxated. The patella lies just above the medial condyle and space can be palpated between the patellar ligament and the distal end of the femur. The trochlea is absent or even convex. The limb is carried, or the animal moves in a crouched position, with the limb flexed.
Diagnosing Patellar Luxation
Examination and Certification

The dog is examined awake (chemical restraint is not recommended) and classified by the attending veterinarian according to the application and general information instructions. The veterinarian then completes the application form indicating the results of the dog’s patella evaluation.

The application and fee can then be mailed to OFA. The attending veterinarian and owner are encouraged to submit all evaluations, whether normal or abnormal, for the purpose of completeness of data. There is no OFA fee for entering an abnormal evaluation of the patella in the data bank.

An OFA number will be issued to all dogs found to be normal at 12 months of age or older. The OFA number will contain the age at evaluation and it is recommended that dogs be periodically reexamined as some luxations will not be evident until later in life.
Preliminary Evaluations

Evaluation of dogs under 12 months of age is encouraged if the owner desires to breed at this age. The most opportune time to gather breeding data is at 6-8 weeks of age prior to the puppy’s release to the new owner.

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

Cardiac Database

General Procedures
Purpose: To gather data regarding heart diseases in dogs, and to identify dogs which are phenotypically normal prior to use in a breeding program. For the purposes of the registry, a phenotypically normal dog is defined as:

One without a cardiac murmur.
One with an innocent heart murmur that is found to be otherwise normal by virtue of an echocardiographic examination which includes Doppler studies.The OFA maintains two separate and distinct cardiac databases: The Congenital Cardiac Database and the Advanced Cardiac Database.

Congenital Cardiac Database

Congenital heart disease in dogs is a malformation of the heart or great vessels. The lesions characterizing congenital heart defects are present at birth and may develop more fully during perinatal and growth periods. Many congenital heart defects are thought to be genetically transmitted from parents to offspring; however, the exact modes of inheritance have not been precisely determined for all cardiovascular malformations. The most common congenital cardiovascular defects can be grouped into several anatomic categories. These anatomic diagnoses include:

Malformation of the atrioventricular valves
Malformation of the ventricular outflow leading to obstruction of blood flow
Defects of the cardiac septa (shunts)
Abnormal develop of the great vessels or other vascular structures
Complex, multiple, or other congenital disorders of the heart, pericardium, or blood vessels

Examination and Classification
Each dog is to be examined and classified by a veterinarian with expertise in the recognition of canine heart disease, in accordance with procedures outlined in The Cardiac Exam section.

Clearance Issued
A breed registry number will be issued for any dog found to be normal for congenital cardiac disease at 12 months of age or older. The exam must include auscultation. There is an initial OFA fee and no charge for recertification at a later age. The breed registry number will indicate the age at evaluation and the type of examiner (C-cardiologist, S-specialist, and P-practitioner).

Preliminary Evaluation
Dogs under 12 months of age can be evaluated for the owner’s information. The most opportune time to gather this data is at 8–10 weeks of age, prior to the puppy’s release to the new owner.

Dogs with Congenital Heart Disease
The veterinarian and owner are encouraged to submit all evaluations, whether normal or abnormal, to help assure accuracy of the database and to assist in the analysis of patterns of inheritance in important canine congenital heart disease. There is no OFA fee for entering an abnormal congenital cardiac evaluations into the database. Abnormal information will not be released into the public domain unless the owner gives permission for this release by initialing the appropriate line on the application form.Cardiac Database

General Procedures
Purpose: To gather data regarding heart diseases in dogs, and to identify dogs which are phenotypically normal prior to use in a breeding program. For the purposes of the registry, a phenotypically normal dog is defined as:

One without a cardiac murmur.
One with an innocent heart murmur that is found to be otherwise normal by virtue of an echocardiographic examination which includes Doppler studies.The OFA maintains two separate and distinct cardiac databases: The Congenital Cardiac Database and the Advanced Cardiac Database.

Congenital Cardiac Database

Congenital heart disease in dogs is a malformation of the heart or great vessels. The lesions characterizing congenital heart defects are present at birth and may develop more fully during perinatal and growth periods. Many congenital heart defects are thought to be genetically transmitted from parents to offspring; however, the exact modes of inheritance have not been precisely determined for all cardiovascular malformations. The most common congenital cardiovascular defects can be grouped into several anatomic categories. These anatomic diagnoses include:

Malformation of the atrioventricular valves
Malformation of the ventricular outflow leading to obstruction of blood flow
Defects of the cardiac septa (shunts)
Abnormal develop of the great vessels or other vascular structures
Complex, multiple, or other congenital disorders of the heart, pericardium, or blood vessels

Examination and Classification
Each dog is to be examined and classified by a veterinarian with expertise in the recognition of canine heart disease, in accordance with procedures outlined in The Cardiac Exam section.

Clearance Issued
A breed registry number will be issued for any dog found to be normal for congenital cardiac disease at 12 months of age or older. The exam must include auscultation. There is an initial OFA fee and no charge for recertification at a later age. The breed registry number will indicate the age at evaluation and the type of examiner (C-cardiologist, S-specialist, and P-practitioner).

Preliminary Evaluation
Dogs under 12 months of age can be evaluated for the owner’s information. The most opportune time to gather this data is at 8–10 weeks of age, prior to the puppy’s release to the new owner.

Dogs with Congenital Heart Disease
The veterinarian and owner are encouraged to submit all evaluations, whether normal or abnormal, to help assure accuracy of the database and to assist in the analysis of patterns of inheritance in important canine congenital heart disease. There is no OFA fee for entering an abnormal congenital cardiac evaluations into the database. Abnormal information will not be released into the public domain unless the owner gives permission for this release by initialing the appropriate line on the application form.

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

Companion Animal Eye Registry (CAER) OVERVIEW

The purpose of the OFA Companion Animal Eye Registry (CAER)acvo_pix is to provide breeders with information regarding canine eye diseases so that they may make informed breeding decisions in an effort to produce healthier dogs. CAER certifications will be performed by board certified (ACVO) veterinary ophthalmologists. Regardless of whether owners submit their CAER exam forms to the OFA for “certification,” all CAER exam data is collected for aggregate statistical purposes to provide information on trends in eye disease and breed susceptibility. Clinicians and students of ophthalmology as well as interested breed clubs, individual breeders and owners of specific breeds will find this useful.

Eye Disease Genetics

Genetic diseases are those that are passed on from parent to offspring through genes that carry the codes for each specific trait. Many of the diseases and disorders that affect the eyes have genetic factors.

How do we identify an inherited eye disease?
Although there are noteworthy exceptions, most of the ocular diseases of dogs presumed to be hereditary have not been adequately documented. Genetic studies require examination of large numbers of related animals in order to characterize the disorder (age of onset, characteristic appearance, rate of progression) and to define the mode of inheritance (recessive, dominant). In a clinical situation, related animals are frequently not available for examination once a disorder suspected as inherited is identified in an individual dog. Maintaining a number of dogs for controlled breeding trials through several generations is a long and costly process. Both of these obstacles are compounded by the fact that many ocular conditions do not develop until later in life. Until the genetic basis of an ocular disorder is defined in a peer-reviewed published report, we rely on what statistical information is available from registry organizations, informed opinions and consensus from ACVO diplomates. We must satisfy ourselves with terms like “presumed inherited” and “suspected to be inherited.” Several companies provide information on genetic testing and greatly assist in providing more information and data to aid in defining the canine genetics of ocular diseases.

There are eye diseases in the dog for which there is evidence of a genetic or heritable cause. The American College of Veterinary Ophthalmologists has listed ten of these diseases as automatic “fails” (this means the affected dog is ineligible to receive an eye certification) because of the significance of the condition to vision and/or the very strong evidence of heritability.

Portions of the material above have been reprinted with permission of the American College of Veterinary Ophthalmologists from the publication “Ocular Conditions Presumed to be Inherited in Purebred Dogs”, 5th Edition, 2010, produced by the Genetics Committee of the American College of Veterinary Ophthalmologists, © American College of Veterinary Ophthalmologists.

See updated ACVO Blue Book on Ocular Disorders.

Eye Exam

Eye Evaluation Criteria: What to Expect During the Exam
OFA Eye Certification examinations are screening exams performed by board certified veterinary ophthalmologists. The exams can take place either in the veterinary office or at a special clinic held in conjunction with another event (such as a dog show).

Bring your dog’s information to the exam so the exam form may be completed properly. Required information includes: registration number, owner’s name and contact information, dog’s registered name, date of birth, sex, breed/variety, and if applicable, permanent identification (via microchip or tattoo).

The exam is performed 30 to 40 minutes after pupil-dilating drops are placed in the eyes. The Eye Certification exam consists of indirect ophthalmoscopy and slit lamp biomicroscopy. It is not a comprehensive ocular health examination, but rather an eye screening exam. For example, Eye Certification exams do not entail measuring tear production, staining the eyes for the presence of corneal ulcers, or measuring intraocular pressures. Gonioscopy, tonometry, Schirmer tear test, electroretinography, and ultrasonography are not routinely performed; thus, dogs with goniodysgenesis, glaucoma, keratoconjunctivitis sicca, early lens luxation/subluxation or some early cases of progressive retinal atrophy might not be detected without further testing. If a serious ocular health problem (such as glaucoma) is suspected during the Eye Certification exam, the examiner will recommend a more comprehensive ocular examination. The diagnoses obtained during an OFA Companion Animal Eye Registry exam refer only to the observable phenotype (clinical appearance) of an animal. Thus it is possible for a clinically normal animal to be a carrier (abnormal genotype) of genetic abnormalities.

The following breeds are recommended to have a preliminary examination prior to initial pharmacological dilation to best facilitate identification of these disorders:

Dalmatian – iris hypoplasia/sphincter dysplasia
Australian Shepherd – iris coloboma
Mastiff – persistent pupillary membrane
Basenji – persistent pupillary membrane
Pembroke Welsh Corgi – persistent pupillary membrane


Eye Registration Procedures

After the painless examination of the dog’s eyes, the board certified veterinary ophthalmologist will complete the OFA Companion Animal Eye Registry (CAER) form and indicate any specific disease(s) found. ecr_stepsThe forms are in triplicate. One copy is for the vet’s records, one is for the owner, and one is for the OFA’s Clinical Database.

Breeding advice will be offered based on guidelines established for that particular breed by the Genetics Committee of the American College of Veterinary Ophthalmologists (ACVO). Bear in mind that the OFA and the ACVO are separate, but cooperating entities. The ACVO only provides their professional services and expertise to ensure that uniform standards are upheld for the certification of dog’s eyes with the OFA.

Once the OFA receives the form from the veterinary ophthalmologist, the information will be recorded for aggregate statistical purposes to monitor breed specific trends and susceptibility. This information will NOT be released to the OFA website, and will NOT result in a certification number unless the owner submits their copy of the form.

The owner has the option of sending their copy of the form, along with appropriate payment, to the OFA for entry into the CAER. Upon owner submission of results to the CAER, dogs with passing results, including those with “breeder option codes,” are issued certification numbers. A report is printed and sent to the owner, and the results are published on the OFA website. Owners also have the option of submitting non-passing results to the registry. If the abnormal release block on the application form is initialed, these results will also be published on the OFA website, although no certification number is issued. In order to encourage open sharing of results, there is no charge to submit abnormal results into the open database.

Certification is valid for 12 months from the date of the eye exam. Annual re-examination is recommended.
CAER Number Eligibility

Conditions that prevent eligibility for an OFA CAER Number There are currently ten disorders for which there is an unequivocal recommendation against breeding in all breeds. These diagnoses are ineligible for OFA Eye Registry certifications. These are conditions which frequently result in blindness and for which there is definite evidence of heritability in one or more breeds.
*Note: The prudent approach to these disorders is to assume they are hereditary except in cases specifically known to be associated with trauma, other causes of ocular inflammation, specific metabolic diseases or nutritional deficiencies.

Keratoconjunctivitis sicca (KCS) – Breeding is not recommended for any animal demonstrating keratitis consistent with KCS. The prudent approach is to assume KCS to be hereditary except in cases suspected to be non-genetic in origin. See above note.
Cataract – Breeding is not recommended for any animal demonstrating partial or complete opacity of the lens or its capsule unless the examiner has also checked the space for “significance of above cataract unknown” or unless specified otherwise for the particular breed. See above note.
Lens luxation or subluxation – See above note.
Glaucoma – See above note.
Persistent hyperplastic primary vitreous (PHPV)
Retinal detachment – See above note.
Retinal dysplasia – geographic or detached forms – See above note.
Optic nerve coloboma
Optic nerve hypoplasia
Progressive Retinal Atrophy (PRA) – Breeding is not advised for any animal demonstrating bilaterally symmetric retinal degeneration (considered to be PRA unless proven otherwise).

Other Factors Regarding Eligibility for an OFA CAER Number

Two categories of advice regarding breeding have been established by the Genetics Committee of the ACVO:
“NO”: Substantial evidence exists to support the heritability of this entity AND/OR the entity represents a potential compromise of vision or other ocular function. Refer to the section titled “Conditions that prevent eligibility for an OFA Eye Certification Number” for a list of disorders with an unequivocal recommendation against breeding, regardless of breed. Click here to see a complete listing of conditions which may make the dog ineligible for a certification number. Some of these conditions are breed specific.
“BREEDER OPTION”: Entity is suspected to be inherited but does not represent potential compromise of vision or other ocular function. Please note, although the dog will ‘pass’ it will have additional documentation on its OFA Eye Certification number with a category listing the problem. Click here to see a listing of Breeder Option Codes. Some Breeder Option Codes are breed specific.
When the breeding advice is ”NO,” even a minor clinical form of the entity would make this animal unsuitable for breeding. When the advice is ”BREEDER OPTION,” caution is advised. In time, it may be appropriate to modify this stand to “NO” based on accumulated evidence. If it becomes apparent that there is insufficient evidence that an entity is inherited, it may be deleted from the list.

================================================================================

Von Willebrand’s disease or VWD

is the most common inherited bleeding disorder in dogs and occurs when there is a lack of functional von Willebrand factor. Von Willebrand factor is needed for the normal adhesion of platelets, and therefore clotting of blood. There are 3 types of von Willebrand’s disease, and type 1 von Willebrand’s disease is the most common. This type is where there is an overall lack of structurally normal von Willebrand factor. It has been reported in over 60 breeds, as well as mixed breed dogs. Not all pups are affected equally when they have von Willebrand’s disease, as the decrease in amount of von Willebrand factor can vary quite a lot. The genetic abnormality has also been described as autosomal dominant with incomplete penetrance, which leads to the high variability in expression. Different mutations have been reported. Some breeds are affected from birth, while others may not be affected until adulthood, or even middle age. DNA tests are available for some breeds, but some dogs that test “positive” may have severe disease, while others may never develop any bleeding tendency. Other dogs are diagnosed by a von Willebrand factor assay, which expresses the level of von Willebrand factor as a percentage. Levels of von Willebrand factor are less than 50% in affected animals, but animals have an increased risk of haemorrhage (i.e. abnormal bleeding tendency) when levels are less than 25-35%. Severe bleeding tendencies are usually associated with levels less than 10-20% (depending on breed). Von Willebrand factor assays are quite variable within an individual, and can be affected by a number of factors, hence repeat testing can be necessary. Signs of von Willebrand’s disease are generally those of abnormal bleeding or prolonged periods of bleeding. If undiagnosed, affected dogs can suffer life-threatening haemorrhage at times of routine surgery or after a traumatic event. Treatment can often be required with blood or plasma transfusions. It is generally recommended to test for this disease (or at least test bleeding times) prior to routine surgery in breeds with a high incidence of the disease (e.g. the Dobermann) and have appropriate transfusion products available in case of a bleeding episode.

==================================================

Progressive retinal atrophy, PRA1 (papillon type)

occurs as a result of degeneration of the Rod type Photoreceptor Cells of the Retina, which are important for vision in low light. Affected dogs typically present between 4 to 6 years of age with poor vision in dim light. On a veterinary eye exam affected dogs have changes in reflectivity and appearance of a structure behind the retina called the Tapetum as well as thinning of the retinal blood vessels, signifying decreased blood flow to the retina. Progressive retinal atrophy, PRA1 (papillon type) is slowly progressive and some affected dogs maintain vision in daylight for many years, sometimes for the remainder of their life.

Progressive retinal atrophy (PRA)

is a collection of inherited diseases affecting the retina that cause blindness.  Each breed exhibits a specific age of onset and pattern of inheritance, and the actual mechanism by which the retina loses function can vary.  The result of almost all types of PRA is similar - generally an initial night blindness, with a slow deterioration of vision until the dog is completely blind.  The age at which the dog becomes fully blind also varies, depending on the genetic disruption present and the breed. Affected eyes are not painful, unless complicated by a secondary problem, such as cataract or uveitis (inflammation due to a leaking cataract). Progressive retinal atrophy (PRA) has been classified in several different ways.  The simplest of these is by age of onset.  Early onset PRA occurs when the affected dog is night blind from birth, and generally is completely blind between 1 - 5 years of age.  Late onset PRA is where the dog is night blind at some time over 1 year of age, and full blindness will occur at a somewhat later stage in life.  Another is by the type of genetic abnormality causing the PRA.  PRA may be inherited by recessive, dominant or sex-linked mechanisms in dogs. For many types of PRA in many breeds a DNA test is now available to allow for easy screening for the disease.  Despite the complexity of the disease and its many forms, ultimately all forms have one thing in common – degeneration of the retina causing progressive loss of vision. DNA tests are not yet available for all affected breeds.  And because breeds may also be prone to several forms of PRA (and not all may have a genetic test available)  examination of the retina by a veterinary ophthalmologist remains a mainstay of the diagnostic testing regimen.   In some breeds with a late onset PRA, serial eye examinations may be required before the signs of retinal degeneration become apparent. The electroretinogram (ERG) is a diagnostic test that the veterinary ophthalmologist may choose to use in some cases and is a very sensitive method of detecting loss of photoreceptor function.  An ERG can be a very good screening test for puppies that may have an early onset form of PRA. Cone-rod dystrophy due to a CORD1variation (a gene mutation at RPGRIP1) is an autosomal recessive form of PRA that occurs in a number of breeds including some types of dachshund (smooth-haired, long-haired and wire-haired), English springer spaniels, and beagles.  There is a DNA test for this type of PRA in all the above-mentioned breeds.  Modifying genes that act on RPGRIP1 have been found, and are thought to affect when the disease becomes apparent (affecting the age of onset of clinical signs). In addition it is thought that there is some degree of variable penetrance seen with CORD1-PRA, which contributes to the wide variation in the clinical syndrome that is seen - for example it is known that the onset of clinical signs may occur between 2 and 10 years of age.  Some cases have been documented of dogs with two copies of the CORD1-PRA mutation and no clinical signs of disease, indicating that indeed other factors contribute to disease expression. In cone-rod dystrophy1, cones degenerate first, followed by rods – this can be detected by the ERG, a specialised test of retinal function.  This is called cone led degeneration.  The cones are the receptors in the back of the eye that detect bright light and different colours.  The rods are the receptors that detect dim light and produce night vision, so dogs with CORD1-PRA do not develop night blindness first as do most dogs with PRA.  These dogs gradually lose all vision, but may initially have better vision in low light than in bright light.  As with all dogs suffering from PRA, there is no cure.  Dogs generally adapt quite well to blindness - especially when it develops gradually - as long as their surroundings remain familiar (e.g. furniture does not get rearranged, they do not move house etc).  They should always be kept on a lead outside the yard, and care should be taken not to startle them.  Balls containing bells (as an example) can be used as toys for mental stimulation.

===================================================

Factor VII deficiency

is a blood clotting disorder that causes excessive or prolonged bleeding after an injury or surgery. With factor VII deficiency, your body either doesn’t produce enough factor VII, or something is interfering with your factor VII, often another medical condition. Factor VII is a protein produced in the liver that plays an important role in helping your blood to clot. It’s one of about 20 clotting factors involved in the complex process of blood clotting. To understand factor VII deficiency, it helps to understand the role factor VII plays in normal blood clotting.

===================================================

Neuroaxonal Dystrophy (NAD)

is a neurodegenerative disease that affects Papillons and Phalenes worldwide.  The disease is characterized by symptoms including head tremors, wobbling gait and inability to stand or walk.  Symptoms appear at a very young age usually between 1-4 months and is clinically characterized by severe axonal swelling with progression to cerebella ataxia, blindness and deafness with most dogs not surviving beyond 1 year of age.