The information on this page was gathered and written by Sandi Hutchins, well known in Cardigan Welsh Corgi circles for her ability to research and answer any question with regard to the history of our beloved Corgis. Therefore this space has been handed over to Sandi to sum up the issue in her own words.
One of the arguments that is being used to “market” the blue merle cross breed corgis is that back in history when the Cardigans and Pembrokes were bred together the Pembrokes carried the blue gene. This is further confused by the list of colours of the Pembroke Welsh Corgi which contains the colour “Blue”.
In today’s PWC standard, blue (often called bluey) refers to dilute, not merle. A dilute Pembroke Welsh Corgi is not a merle, does not have spots or patches, and is genetically different from blue merle. It is seriously faulted in the PWC Standard.
While it is true that there were a very small number of blue merle Pembroke Welsh Corgis shortly after the two breeds were “separated” officially, they were soon regarded as resulting from Cardigan blood and by the time the second Pembroke breed standard was adopted in 1946, the wording under colour had been changed from “any color but white” to a list of approved colors including reds, sables, and tris… but not including blue merle.
When speaking of the separation of the two breeds it is easy to get confused and think that there was a lot of breeding back and forth between them, but that is not the case. There were groups favoring either the Pembroke or Cardigan and in most cases, the two were not bred together. They were shown from 1925 until 1934 in the UK in Welsh Corgi classes, and within the classes were sometimes divided and sometime competed against each other. Once they were officially separated under UK registration, they each had their own stud books and separate breed classes at shows. The stud books remained open only long enough to include the original foundation stock (either PWC or CWC) and then closed. In order to be considered purebred, Cardigans and Pems must be able to be traced all the way back to the early 30’s and the original foundation stock of each breed.
So, you may ask, isn’t it possible for the blue merle gene to travel undetected through the generations and just pop up in a Pembroke litter?
The answer is no. In order for it to travel undetected, there must be the presence of the ee (clear red) gene which affects every black hair on a dog’s body, causing it to turn a shade of red from cream or yellow or pinkish red. A merle, brindle, tricolor or sable puppy would just be a shade of red as the merle, brindle, tricolor and sable coloring would be hidden.
Genetic testing has shown that the Pembroke Welsh Corgi does not carry the E or e gene, so a “hidden” merle is impossible. In Cardigan Welsh Corgis the blue merle color was resurrected using dogs which carried the merle gene hidden. That is not possible in Pembrokes without the E.
So, the answer is, if it is a blue merle Pembroke Welsh Corgi, it is a mixed breed.
Note: Information gathered from Thelma Evans Gray (Rozavel) in her four books, The Welsh Corgi, 1934, 1939, 1947 and 1952.