Australian Shepherd Coat Pattern Genetics

There are two basic patterns of the Australian Shepherd - Merle & Solid.  If you breed Merle to Merle, you need to be aware of the Lethal White Merle gene.  Simply put - Lethal White is the presence of TWO merle genes, one obtained from each parent.  

If there is ONE merle area on the dog, no matter what size it is, the dog is a Merle.

Breeding merle to merle will present you with the possibility of having 25% of your litter carrying the Lethal Merle gene.  These pups will be (or soon become) blind and/or deaf.  To be safe and not have to cull any pups - breed Merle to Solid

To be considered sound:
Each eye must be surrounded with color other than white.

Each ear must be covered with color other than white.

No white on the body behind the shoulder.

No white up the stifle on the hind leg into the body.

The following would be a cross between a merle dog and a solid dog:

MM = solid   Mm = merle

MERLE x SOLID
	M	M
M	MM	MM
m	mM	mM

50% chance for Merle pups
50% chance for Solid pups

The following would be a cross between a merle dog and a merle dog:

MM = solid   Mm = merle mm = lethal merle

MERLE x MERLE
	M	m
M	MM	Mm
m	mM	mm

25% chance pups will be SOLID
75% chance pups will be MERLE with a 25% chance of a Lethal Merle gene combination

The following would be a cross between a solid dog and a solid dog:

MM = solid   M m = merle

SOLID x SOLID
	M	M
M	MM	MM
M	MM	MM

All resulting pups will be SOLID