PKD Proposals to go before the CA AGM in August 2003:
Proposed by David Brinicombe
Seconded by Birgit Solstein
Addition to the CA Registration rules:
PKD Proposal 1
Passed with amendments, CA AGM 10 August 2003
All entire Persians and Exotics over 10 months of age which are imported from
another registry must hold a valid PKD Test Certificate.
Export transfers will only be issued for Persians and Exotics over 10 months of age
which hold a valid PKD Test Certificate.
PKD Proposal 2A
Passed CA AGM 10 August 2003
Any Persian or Exotic kitten will be initially registered as not for
breeding unless both its parents hold a valid PKD Test Certificate.
This restriction can be removed by the Breeder if such a kitten is
subsequently granted a valid PKD Test Certificate after the age of 10
months.
Alternative PKD Proposal 2B
Withdrawn when 2A passed, CA AGM 10 August 2003
Any Persian or Exotic kitten will have its Official Pedigree marked:
"Parent(s) not tested for PKD (kidney disease)" unless both its parents
hold a valid PKD Test Certificate.
PKD Proposal 3
Passed, CA AGM 10 August 2003
If any cat of any breed is diagnosed with PKD by testing or by post
mortem examination, the National Breeding Committee must be informed and
their advice taken.
Information:
These rules introduce Certificates of Testing for PKD for Persians and
Exotics which have a known high risk of Polycystic Kidney Disease.
Available testing statistics show a risk of 35% to 40% for these breeds.
(See Note 1)
A valid PKD Test Certificate is one issued through the FAB PKD Screening
Scheme or a recognised overseas equivalent stating that cysts have not
been seen. (see Note 2)
The designated breeds can be redesignated in the future by
recommendation of the National Breeding Committee if testing results in
the elimination of PKD from these breeds. (See Note 3)
Rationale for all PKD Proposals:
These proposals have been welcomed by Professor Timothy Gruffydd-Jones,
Professor of Feline Medicine, Bristol University and by Martha Cannon,
Head of the FAB PKD Testing Scheme.
About 6000 Persians and Exotics are registered in Britain each year. If
only half of their parents have been tested this still suggests that
over 1000 kittens are likely to have PKD each year. Experts suggest that
most positive cats will die before they are ten years old.
Two complete generations of testing could reduce this number to single
figures. These very few positive cats would soon be eliminated by
further testing.
At the 2003 GA, 13 FIFe Members voted in favour of a proposal which
would have made PKD testing compulsory. CA has lagged behind many other
FIFe Members in setting up PKD testing, but many breeders already test
voluntarily.
It is likely that Britain, as originators of the breed, has exported PKD
to the rest of the world. PKD is caused by a single dominate gene which
is detectable in most cases by ultrasound scanning. PKD could have been
eliminated many years ago.
The available test for PKD is not 100% accurate, but its accuracy of
around 95% could virtually eliminate PKD from a breed in two complete
generations of testing. Only a very few positive cats would remain, and
further testing would soon eliminate these.
PKD was identified in 1969 and testing by ultrasound scanning was
developed in 1996. The FAB PKD Screening Scheme was set up in 2000. PKD
has become very common in affected breeds and action towards eliminating
PKD is a priority.
Rationale for PKD Proposal 1
There is no point in testing and eliminating PKD unless the CA Registry
is ring fenced against the reintroduction of PKD.
To preserve the reputation of the CA Registry, all exported cats should
be tested for PKD.
Rationale for PKD Proposals 2A and 2B
Two alternative PKD Proposals are offered. PKD Proposal 2A would lead to
the virtual elimination of PKD. PKD Proposal 2B would raise the
awareness of the disease and identify breeding cats which have not been
tested for PKD, but would not eliminate the disease.
There is a tightrope to be walked. Too strict a rule would lead to poor
compliance and too lax a rule would allow many untested cats to be used
for breeding. Either of these extremes would not eliminate PKD.
Any rule concerning testing must allow for the breeding of positive cats
in order that replacement cats can be bred to avoid damage to the breed
gene pool. (See Note 4)
Once elimination of PKD in a breed is achieved, that breed can be
regarded as having no risk of PKD.
Rationale for PKD Proposal 3
PKD rules could be applied to all breeds, but this would cause a great
deal of opposition.
There are only reliable data for the incidence of PKD in Persians and
Exotics. (see Note 3) However, PKD should be a notifiable disease in any
breed as any occurrence could easily be eliminated by a testing scheme
based on a pedigree analysis under the guidance of the CA National
Breeding Committee.
Note 1
Polycystic Kidney Disease is caused by a single dominant gene. PKD
usually causes a premature and painful death in positive cats from
kidney failure.
For over ten years, PKD could be diagnosed by ultrasound scanning at the
age of 10 months or over. It is a disease which could easily have been
eliminated within two generations of breeding.
Note 2
Many registries require PKD Certificates from a recognised PKD
certification scheme. These certificates are normally recognised as
valid by other registries, including the CA.
The cat must be over 10 months and be microchipped, with the number
given on the certificate.
A valid PKD Test Certificate will normally state that cysts have not
been seen by a suitably qualified sonographer. It cannot guarantee that
a cat is negative.
An uncertificated cat is treated as a cat which is positive for PKD.
Note 3
The breeds most at risk are Persians and Exotics. Testing has shown that
these cats show an incidence of PKD of 35% to 40%.
Breeds which have registered crosses with Persians or Exotics are also
at some risk. These include British, Burmilla and Folds. Making PKD a
notifiable disease as in PKD Proposal 3 should identify any positive
cats in other breeds.
The responsibility for redesignating breeds at risk of PKD lies with the
CA National Breeding Committee. The hope is that within a few
generations, PKD will no longer be found in any designated breed.
Note 4
Following studies on PKD during the setting up of the FAB PKD Screening
Scheme, expert opinion suggested that automatic neutering of all PKD
positive cats could cause damage to a breed gene pool. This advice is
also given in the FAB PKD web pages.
Under Proposal 2A or Proposal 2B, a cat without two Certificated parents
or is positive for PKD may be used for breeding a replacement negative
cat. This means that a cat which is valuable to the breed gene pool may
be bred with a cat which holds a valid PKD Test Certificate in order to
preserve its genetic qualities.
This is especially important where the gene pool is known to be small as
in some colour varieties.
On average, half the kittens from a positive X negative mating will be
positive, and provisions must be made for the welfare of these kittens.
last updated 6 June 03: