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The OptiGen prcd-PRA marker test & Results of testing of "Littleriver Tollers"
     The Optigen prcd test for Tollers 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 a marker test rather than a mutation-based gene test.
     This means that it identifies dogs by a "fingerprint" on chromosome 9 near the
     prcd gene locus, rather than by detecting the prcd mutation itself. The result of the
     test is a genotype or pattern - a fingerprint - that allows the separation of dogs
     into three groups: pattern/genotypes A, B and C. Due to the properties of the
     DNA markers, there is a low risk of recombination - or dissociation - between
     these markers and the prcd gene. Therefore, this marker test classifies ACDs
     and Tollers into three risk groups as shown in this Table.

Possible results using the OptiGen prcd test

Pattern/Genotype* Risk Group Significance For Breeding Risk For Developing prcd

                     A I. Normal Can be bred to any dog,
with 99.5% confidence of
producing no affected pups Not expected to develop prcd, risk is less than 0.0025%

                     B II. Nonaffected Probably a carrier of prcd
(99.0% confidence)and
should be bred only to
Pattern A Not expected to
develop prcd, risk is
less than 0.5%

                     C III. High Risk Probably homozygous for
prcd(99.5%                               confidence)and should be
bred only to Pattern A Probably will develop
prcd, with only 0.5%
chance of not being
affected.

* Probability risks are based on estimated frequency of recombination between the prcd
markers and the disease gene.

The next table shows that all the desirable breedings include at least one parent
with Pattern A genotype from the OptiGen prcd test. All other breedings are at
risk of producing pups of Pattern C, with a high probability of developing prcd.
However, all dogs can be bred with a high degree of safety. It isn't necessary - or
even desirable - to remove dogs from the breeding population. But when
choosing pups to retain as potential breeding stock, it is important to select for
dogs with Pattern A genotype - and select against dogs with Pattern C genotype.

Expected results for breeding strategies using the OptiGen prcd test
                                                                                                        Parent 2     Genotype

Parent 1
         Genotype                    A                       B                        C

                    A All = Pattern A 1/2 = Pattern A
                 1/2 = Pattern B All = Pattern B

                    B 1/2 = Pattern A
                    1/2 = Pattern B 1/4 = Pattern A
         1/2 = Pattern B
                  1/4 = Pattern C 1/2 = Pattern B
                 1/2 = Pattern C

                    C All = Pattern B 1/2 = Pattern B
                 1/2 = Pattern C All = Pattern C

     The OptiGen prcd test can be done reliably at any age, and the test result will
     never change with age.

Optigen Results of Tollers tested from Littleriver Kennels Perm Reg'd.

DNA Test Report April 30, 2002

Registered Name CKC Registration # Test Result Optigen Accession #

Ch Littleriver's Argus (GUS) ( Male ) HG504379 P/G A 02 - 742

Littleriver's Dancing Decoy (Male) KY698368 P/G A 02 -746

BISS CH Littleriver's Delhaven Dancer (Male ) GN451985 P/G B 02 - 745

Littleriver's Christmas Bell (Female) JY633486 P/G A 02 - 743

Littleriver's Modeline (Female) JY630507 P/G A 02 - 744

Littleriver's Tess (Female) CS217431 P/G A 02 - 748

Beinnbhreaghs Double Cross (Female) KG675284 P/G A 02 - 749

Littleriver"s Bounty (Female) LA705374 P/G A 02 - 750

Littleriver's Cinnamon (Female) HW549633 P/G A 02 - 751

Littleriver's Lady In Red (Female) EJ261798 P/G B 02 - 747

DNA Test Report June 28, 2002

Littleriver's El Zorro (Male) LW763652 P/G A 02 - 1562

Littleriver's Lady Scarlet (Female) MC782329 P/G A 02 - 1564

Anemone Of Great Pleasure (Female) 1076758 P/G A 02 - 1565

Shaggy Toller's Littleriver Yenta (Female) 1076289 P/G B 02 - 1566

Britany Toller Bryvilsar (Female) 1075141 P/G B 02 - 1563

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Pattern/Genotype*	Risk Group	Significance For Breeding	Risk For Developing prcd
A	I. Normal	Can be bred to any dog, with 99.5% confidence of producing no affected pups	Not expected to develop prcd, risk is less than 0.0025%
B	II. Nonaffected	Probably a carrier of prcd (99.0% confidence)and should be bred only to Pattern A	Not expected to develop prcd, risk is less than 0.5%
C	III. High Risk	Probably homozygous for prcd(99.5% confidence)and should be bred only to Pattern A	Probably will develop prcd, with only 0.5% chance of not being affected.

Parent 1 Genotype	A	B	C
A	All = Pattern A	1/2 = Pattern A 1/2 = Pattern B	All = Pattern B
B	1/2 = Pattern A 1/2 = Pattern B	1/4 = Pattern A 1/2 = Pattern B 1/4 = Pattern C	1/2 = Pattern B 1/2 = Pattern C
C	All = Pattern B	1/2 = Pattern B 1/2 = Pattern C	All = Pattern C