Eye Diseases

Eye conditions are the focus of the Eye Committee

Distichiasis: Eyelashes abnormally located in the eyelid margin which may cause ocular irritation. Distichiasis may occur at any time in the life of a dog. It is difficult to make a strong recommendation with regard to breeding dogs with this entity. The hereditary basis has not been established, although it seems probable, due to the high incidence in some breeds. Reducing the incidence is a goal. When diagnosed, Distichiasis should be recorded; breeding discretion is advised.

Cataracts: An opacity of the lens and or its capsule, which may affect one or both eyes and may involve the lens partially or completely. In cases where cataracts are complete and affect both eyes, blindness results. Surgery may be an option, but it is very expensive.

The prudent approach is to assume cataracts to be hereditary except in cases known to be associated with trauma, other causes of ocular inflammation, specific metabolic diseases, persistent pupillary membranes, persistent hyaloid or nutritional deficiencies. The exact frequency and significance of cataracts in the breed is not known. Some cataracts have been diagnosed as young as eight weeks of age during a Companion Animal Eye Registry (CAER) examination.

Persistent Pupillary membranes: Persistent blood vessel remnants in the anterior chamber of the eye which fail to regress normally in the neonatal period. These strands may bridge from iris to iris, iris to cornea, iris to lens, or form sheets of tissue in the anterior chamber. The last three forms pose the greatest threat to vision and when severe, vision impairment or blindness may occur. The exact frequency and significance of this disorder in the breed is not known. This can be diagnosed by a CAER exam at eight weeks of age.

Prior to breeding a dog that had a diagnosis of a PPM on their 8 weeks exam, have your veterinary ophthalmologist examine the eyes prior to dilating the pupil. Small peripheral unresolved PPMs can be obscured in the dilated pupil.

PRA Resources

Eye Exam Check List Form
Frequently Asked Questions

Microphthalmia and multiple congenital ocular anomalies: This is a congenital abnormality present bilaterally and characterized by a small globe and associated ocular defects which can affect the cornea, anterior chamber, lens and/or retina. These associated defects may be variable in severity. Several cases have been identified, all of which appeared to have a common ancestry. All affected animals so far identified have been the progeny of dogs that were phenotypically normal, suggesting that the defect is not dominantly inherited. This can be diagnosed by a CAER exam at eight weeks of age.

Dogs with microphthalmia should not be used for breeding.

There is a syndrome commonly known as Puppy Eye Syndrome or PES. Signs of PES include microphthalmia along with other non-eye related conditions. A dog can have microphthalmia and not have PES. Further information on PES can be found on the Neonatal and Pediatric Health page. 

Progressive Retinal Atrophy (PRA): PRA is a group of inherited diseases that cause irreversible degeneration of the retina and eventually causes blindness.

PRA was first reported in the Portuguese Water Dog in 1990 in the form of prcd-PRA (progressive rod-cone degeneration). At that time the PWDCA and their members supported the research work of Dr. Gustavo Aguirre and Dr. Greg Acland and their associates at the University of Pennsylvania. Drs. Aguirre and Acland then moved to Cornell at the Baker Institute where most of the research on the prcd form of PRA was done. They identified the gene for prcd PRA which affects many different breeds and developed a test for the gene. OptiGen was started in 1998 and first started running a marker based test for prcd PRA as research continued at the Baker Institute to identify the mutation gene. The prcd PRA mutation gene was identified in 2005.

Dr. Aguirre returned to the University of Pennsylvania and continues his research and teaching. Dr. Acland retired from Cornell.

In the fall of 2012, a new form of PRA was reported in the breed and the club again contacted Dr. Aguirre to work on this new early form of PRA named EOPRA for (early onset PRA). Dr. Aguirre and Dr. Keiko Miyadera research has identified the gene causing EOPRA and developed a DNA mutation gene test to identify dogs that are either normal, carriers or affected. Both prcd-PRA and EOPRA are mutation gene tests. The current tests for prcd and early onset forms are available from OptiGen. Please go to https://www.optigen.com for more information.

Normal/Clear, Carrier, and Affected are used to designate a dogs test results. Carrier and Affected dogs should only be bred to Normal/Clear to avoid producing PRA-affected puppies. OptiGen results should not be used to determine if a dog should be used for breeding, or not used for breeding. For information on having a dog OptiGen tested go to: https://www.optigen.com.

What the PWDCA is doing:

The PWDCA recommends that all dogs used for breeding have an annual CAER examination. A CAER exam is only good for one year and can only be done by a board certified ophthalmologist.

To truly have knowledge about the overall eye health of the breed, it is just as important to have regular eye exams for our companion/pet PWDs. For the companion/pet dogs that are older than 4 years old, if no symptoms of eye problems are noticed, an eye exam no less than every other year, recorded with an eye registry, until the PWD is at least 10 years old is recommended.

To avoid confusion, it is important to be aware of new changes that have occurred in regards to the American College of Veterinary Ophthalmologist (ACVO) and Canine Eye Registration Foundation (CERF). Effective November 1, 2012, the ACVO will no longer continue to be involved with CERF, and will transition affiliation with to an Orthopedic Foundation for Animals registry (OFA). This new registry will be called the OFA Companion Animal Eye Registry (CAER).

It is just as important to have as many apparently normal pet dogs evaluated as well so that we can identify the scope of the problem in our breed. As local CAER clinics arise, please encourage all PWD owners to get their PWDs in for an CAER exam. Please make sure the exam is recorded on the CAER form. This will insure that the eye exam data reaches the database and is available for the researchers. A veterinary ophthalmologist can be found near you at the American College of Veterinary Ophthalmologists website: http://www.acvo.org/.

Why the PWDCA is addressing this:

Most eye diseases are not widespread throughout the breed, but any disease that impairs a dogs sight can be devastating to the owner, particularly those that can cause blindness. For answers to questions about getting your dog eyes examined and living with a vision-impaired dog, read the Frequently Asked Questions.

 
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