ACDs and ASTCDs are white dogs (except for any solid colour patches). Pups are white at birth. Colour intensity commonly (but not always) increases with age and varies from one part of the dog’s body to another.
These colour changes are under the control of the ticking gene. The ticking gene, T, causes speckling or mottling of colour (black or red) to develop over the white by increasing the proportion of coloured (black or red) hairs versus white. Continue reading