This is the second article in a series about Jack Russell eyes. The first article is published online at www.myjackrussellterrier.com and in the summer 2003 newsletter for the Jack Russell Terrier Club of Canada.
By now most Jack Russell owners and breeders have heard the term "CERF test" many times. Many of us tell people that our dogs are CERF Normal but we may not be using that term correctly. In speaking with Karen Graham, a Canine Eye Registration Foundation (CERF) staff member, she stated that "CERF" is a term that is reserved for dogs with current test results that are certified with the Canine Eye Registration Foundation."
How can you certify your dog's annual eye exam? When you have a dog examined by an ACVO board-certified ophthalmologist for the CERF certification, the doctor will fill out a CERF form. One copy of that form is yours, one is for the doctor's file and one goes to the Veterinary Medical Database at Purdue University for veterinary research. You need to fill out the backside of your copy of the test and send it to CERF to request certification. Until you receive a CERF certification number from them your dog is technically not CERFed.
The CERF certification number is proof that your dog has passed CERF's guidelines. At the owner's discretion, results can be kept confidential or they can be posted on-line at the CERF website www.vmdb.org. Breeders can choose to certify their dogs and tell buyers to check the results of the tests on the CERF website. Certification is intended to eliminate uncertainty and to help make better breeding decisions based on information from a reliable, objective third party. You might be able to look up a stud dog that you are considering or look up a related dog to check their results. The CERF database is one tool that can be utilized by Jack Russell breeders to help improve the breed.
CERF Breeding Stock
The JRTCA has just revised the Breeders' Code of Ethics. In the code it
states twice, "BAER and annual CERF testing of all breeding stock
are strongly recommend." A breeder should require a copy of the CERF
test or CERF certification before breeding to a bitch or stud dog and
look for a Normal diagnosis for that terrier. The CERF form has a bubble
for Normal test results. The vet will mark this box if your dog has no
heritable eye disorders that would cause vision impairment or blindness.
You should also check the date of the exam to make sure that it is current.
To become familiar with the Breeders' Code of Ethics visit this link:
www.jrtcabreeders.com/Code_of_Ethics/code_of_ethics.htm
Juvenile Cataracts
Because there is so much concern about Juvenile Cataracts, people are
confused about the terminology associated with them. Juvenile Cataracts
means simply that a cataract that is diagnosed early in life. In the Jack
Russell breed this can be anywhere between birth and about 5 or 6 years
old. Because these cataracts can happen anytime within this age range,
breeding dogs should be examined for CERF certification annually. If a
cataract has been diagnosed, the veterinarian will describe the location
on the lens where it appears. The LENS boxes on the CERF form note possible
locations of cataracts (anterior cortex, posterior cortex, equatorial
cortex, anterior sutures, posterior sutures, nucleus, capsular, or generalized).
The eye vet will also make a drawing of the abnormalities in the circles
on either side of the Lens category on the form. There are two circles
for each eye, one circle showing the eye from two different perspectives
where the vet will draw his observations.
Cataract Terminology
Terms that are used to describe the shape and physical characteristics
of the cataract are often confusing. Some of these terms are punctate,
pinpoint, feathering, diffused and y-suture. Punctate or pinpoint cataracts
are small dots on the lens. Often these dots are the beginning of a progressive
cataract but they can also be stable. If the vet does not know or have
any reason to suspect that the dots are going to be progressive, the "significance
of above punctate cataract unknown" box may be filled in by the vet.
The dog may still pass its CERF exam until the cataract shows progression.
It is the breeder's option to continue breeding dogs with this type of
diagnosis. CERF explains, "the dog has a condition indicated on the
exam form other than normal that is considered a "Breeders Option"
in the ACVO (American College of Veterinary Opthalmologists) Ocular Disorders
Book. The ACVO Genetics Committee has devised this system to help control
various conditions that are not necessarily problematic, do not cause
vision impairment, and may not be hereditary. They recommend that you
try to breed these dogs to others that do not have the same category."
Dots or lines can be located along the Y- sutures of the lens and these
are referred to as Y-suture cataracts if they progress along the y-suture
lines. Cataracts can progress along the Y-suture lines as a line, or by
diffusing or feathering out. This spreading cloudiness can take place
relatively quickly or it could be at a much slower rate and eventually
may involve the entire lens.
Cataracts can be genetic or some trauma such as injury, nutritional deficiencies, or diseases such as diabetes can also cause them. According to ACVO veterinary ophthalmologist, Dr. Ann Gratzek of Monterey, California "Genetically caused cataracts are generally cataracts that progress and involve the cortex of the lens. Dogs with genetic cataracts are not CERF certifiable and should not be bred."
Although more data is currently being gathered about Jack Russell juvenile cataracts at UC Davis, there is little that is currently written up about JRT Juvenile Cataracts in the veterinary or scientific communities. Jack Russell owners like you can help by supporting genetic research efforts and submitting cheeks swabs to research.
Reference Links
Article: Yearly CERF exams - Why are they important? By Sheryl Krohne,
DVM
www.vmdb.org/aug02.html#dxspot
Article: Juvenile Cataracts Progression, by Sandi Pensinger www.myjackrussellterrier.com/research.html
CERF website
www.vmdb.org
UC Davis JRT Eye Study
cgap.ucdavis.edu
JRTCA Breeders Code
of Ethics
www.jrtcabreeders.com/Code_of_Ethics/code_of_ethics.htm
American College of
Veterinary Opthalmologists
www.acvo.com
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