Harriot Roy 218222 is not a registered carrier of CEA. His father Vic
Morris' Mac 183767 has produced a pup suffering from CEA which makes Mac
a suspected carrier of CEA. If Mac is a carrier then Harriot Roy has a
50% probability of also being a carrier. You can not tell this by an
opthalmic test (vet looking into his eyes). Such an opthalmic test is
compulsory I think in the UK before a dog can be used to breed from and
also before running in the big UK trials. You can only tell that he
isn't a carrier by doing a genetic test (for instance by Optigen in the
USA).

People easily get confused by the statement "he was eye tested" thinking
that he then cannot be a carrier. But if it only was an ophthalmic test,
then he can be a carrier and he can produce children affected by CEA.
This holds for both Mac 183767 and Roy 218222. Where Mac meanwhile has
produced a CEA suffering pup so he is a carrier unless the vet made a
mistake. By the way this could be the case because a CEA carrying dog on
average produces 1 pup suffering CEA on every 100 pups he produces. Mac
produced 350 pups so should have in the order of 3 CEA suffering
children. But he only has one. So it is possible that this single CEA
pup is just a misinterpretation of the vet.

The child of Vic Morris' Mac 183767 that suffered CEA was born in March
1995: Katie 220095. She was probably diagnosed having CEA in 1997. After
1997 Vic Morris' Mac didn't sire any litters.

You can only be sure that a dog isn't a carrier by doing a genetic test.
If I know that a dog was geneticly tested clear, then it will show on
the pedigrees that I compile by a green "e" (older pedigree) or "en"
(CEA-normal on newer pedigrees). If it was geneticly tested to be a
carrier, or proven so because having CEA suffering children, then it
will be shown as a red "e" in the pedigrees.

So if you like to have certainty for Harriot Roy 218222, you should have
him geneticly tested.
Even if Roy gets tested CEA-normal (no carrier) it doesn't tell anything
about the status of his father Mac. Mac could still be a carrier.

I admit that this is complex stuff, but I still hope it helps.

Kind regards,

Teun van den Dool
www.bcdb.info