BRCC Research Regarding Persistent Pupillary Membranes (PPMs) February 27, 2009
There has recently been some discussion on the breeder chat regarding CERF certificates and Persistent Pupillary Membranes (PPMs).
The BRCC has done some investigation and research on this topic, as requested by a member.
As a preface, it is noted that CERF does not issue certificates for dogs who have hereditary eye disease that they believe, based on the
research and medical opinion of the Genetics Committee of The American College of Veterinary Ophthalmologists, would pose a breeding
risk. In other words, they recommend that any dogs used for breeding should have a CERF certificate issued in the past twelve months.
Dogs who have not been issued a CERF certificate within the previous twelve months should not be used for breeding.
The basic questions have been these:
Q: Does CERF issue certificates for dogs with PPMs?
A: CERF does issue certificates for dogs diagnosed with iris to iris PPMs. It is listed as a breeder option, which, according to CERF,
means that breeders should take care not to breed these dogs to other dogs with the same diagnosis. Please see the discussion of and link
to the article on the CERF website entitled "Persistent Pupillary Membranes in Dogs" for further information. It is copied and pasted below
the Q and A.
Q: Does CERF issue certioficates for dogs diagnosed with other types of PPMs?
A: CERF does not issue certificates for dogs diagnosed with iris to cornea, iris to lens or iris to iris sheet (also called sheeting) PPMs.
Q: Is this a change?
A: Yes. On April 12, 2006, CERF stopped issuing certificates for dogs diagnosed with those three types of PPMs mentioned above.
Q: Why would CERF do that?
A: CERF follows the recommendations of the Genetics Committee of The American College of Veterinary Opthalmologists. Their
recommendations are based on their research on each breed that participates in CERF and their recommendations are breed specific. A
member shared a link to the 2007 publication and that link as well as the section on the ISD are copied and pasted below for further
Q: Does the parent breed club have any input into those decisions or can they influence the decisions?
A: No. The decision of CERF to issue or not issue certificates is based on the recommendation of the Genetics Committee of The
American College of Veterinary Ophthalmologists as they are the experts in this field. They issue their findings in the Ocular Disorders
Presumed to be Inherited in Pure Bred dogs.
Each year, when the book is released, information is posted on the CERF website and the book is available for purchase by members.
Unfortunately, the 2008 edition is sold out and the 2009 edition has not yet been released so the most current information is available only
by telephone from CERF.
This is a link to an article on the CERF website entitled, Persistent Pupillary Membranes in Dogs, which gives a general overview of PPMs.
http://www.vmdb.org/dx1.html . The following was copied and pasted from that text, with relevant areas highlighted in yellow for ease of
"In general, iris to iris PPMs cause no problems. They may be single strands or a forked structure. These PPMs may break and become
less prominent as the puppy gets older, but they usually do not disappear completely. Iris to lens PPMs are more problematical. These
PPMs cause opacities (cataracts) at the point where they are attached to the lens capsule. The cataracts do not usually progress and cause
only minor visual deficits. Iris to cornea PPMs cause opacities on the cornea due to their ability to damage the corneal endothelium (the
inner lining of the cornea). These opacities may be small or may be severe due to the development of corneal edema (fluid in the cornea).
Severely affected puppies (with numerous strands) may be blind (they may improve as they get older). The strands may regress but do not
PPMs are found in many breeds of dog. In most of these breeds, iris to iris PPMs are classified by CERF as a "breeder option" problem.
This means that most of the PPMs which have been reported in these breeds have been small and are probably sporadically occurring and
not hereditary defects. Dogs with these small iris to iris PPMs who have been bred have not been reported to have puppies with vision
problems. This does not mean that problems will never occur in these breeds. Owners with dogs diagnosed with PPMs should be aware of
the situation and should probably either not breed affected dogs or should breed the affected dogs only to unaffected dogs."
The following text was copied and pasted from the Occular Disorders Presumed to be Inherited in Purebred Dogs, 5th Edition 2007
written by the Genetics Committee of The American College of Veterinary Opthalmologists. The link to the publication was submitted in
the breeder chat by a member.
It is http://www.vrcc.com/ophthamology/docs/OcularDisordersCanine2007.pdf if any of you would like to review the entire document.
The information comes from Section I of the Breed Information. The relevant areas are highlighted in yellow but the entire section devoted
to the Icelandic Sheepdog is included.
ICELANDIC SHEEPDOG - 1
©2006, American College of Veterinary Ophthalmologists
DISORDER INHERITANCE REFERENCE BREEDING ADVICE
A. Persistent pupillary Not defined 1 Breeder option
-iris to iris
B. Retinal dysplasia Not defined 2 Breeder option
Description and Comments
A. Persistent pupillary membranes (PPM)
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 from 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.
B. Retinal dysplasia-folds
Linear, triangular, curved or curvilinear foci of retinal folding that may be single or multiple.
When seen in puppies, this condition may partially or completely resolve with maturity. Its
significance to vision is unknown. There are two other forms of retinal dysplasia
(geographic, detached) which are known to be inherited in other breeds and, in their most
severe form, cause blindness. The genetic relationship between folds and more severe
forms of retinal dysplasia is undetermined.
There are no references providing detailed descriptions of hereditary ocular conditions of the
Icelandic Sheepdog breed. The conditions listed above are generally recognized to exist in the
breed, as evidenced by identification on breed eye screening examinations and/or clinical
experience of veterinary ophthalmologists.
1. ACVO Genetics Committee 2005 and/or Data from CERF All-Breeds Report, 2003-2004.
2. ACVO Genetics Committee, 2006 and/or Data from CERF All Breeds Report, 2001-2005.
CERF OCULAR DISORDERS REPORT
1991 - 1999 2000-2005
Diagnostic Name Number Percent Number Percent
TOTAL NUMBER OF ICELANDIC SHEEPDOG EXAMINED 23 219
ENTROPION 4 1.83%
DISTICHIASIS 1 4.35% 2 0.91%
ANY PERSISTENT PUPILLARY MEMBRANES DIAGNOSED 11 5.02%
PERSISTENT PUPILLARY MEMBRANES IRIS TO IRIS 11 5.02%
PERSISTENT PUPILLARY MEMBRANES IRIS TO CORNEA 1 0.46%
ANY CATARACT DIAGNOSED (MARKED WITH *) 1 4.35%
ANTERIOR CORTEX INTERMEDIATE* 1 4.35%
ANT. CORTEX PUNCT. SIGN. UNKNOWN 1 0.46%
POSTERIOR CORTEX INTERMEDIATE* 1 4.35%
POST. CORTEX PUNCT. SIGN. UNKNOWN 1 0.46%
EQUATORIAL CORTEX INTERMEDIATE* 1 4.35%
EQUATORIAL CORTEX PUNCT. SIGN. UNKNOWN 2 8.70%
CAPSULAR SIGN. UNKNOWN 3 1.37%
PERSISTENT HYALOID ARTERY 1 0.46%
RETINAL DYSPLASIA FOCAL/FOLDS 1 4.35% 3 1.37%
OTHER, INHERITED 1 0.46%
OTHER, NON -INHERITED 10 4.57%
NORMAL 18 78.26% 195 89.04%
1. PERCENTAGES ARE BASED ON THE TOTAL NUMBER OF DOGS FOR THE BREED THAT HAVE BEEN REPORTED.
2. THE "ANY CATARACT DIAGNOSED" CATEGORY COUNTS ANY INDIVIDUAL DOG ONLY ONCE AND INCLUDES
CATARACTS THAT ARE CONSIDERED SIGNIFICANT.
3. THE "ANY PERSISTENT PUPILLARY MEMBRANES DIAGNOSED" CATEGORY OR "ANY RETINAL DYSPLASIA
DIAGNOSED" CATEGORY COUNTS ANY INDIVIDUAL DOG ONLY ONCE.
Thanks to the members who raised questions and issues. We have learned quite a bit from this research and hope that you will, too.