the ACD should NOT have a domed skull and a short muzzle, it should NOT have a definite stop between the skull and muzzle.
The planes of the head from the side must be parallel and the skull only slightly rounded on sided but flat on top.
When the skull is prominent (domed) the dog is at risk of having it’s skull kicked off by a cow. When the stop is indented or definite the cow’s hoof can easily kick the dog in the skull.
A correct head has a slight stop and a flat skull. Then the cow’s hoof is deflected (slides off more easily) if the dog is kicked.
If an ACD has a short muzzle this will give it breathing problems and will limit endurance. Often when we see dogs with short muzzles they are ‘snorting’ or puffing after running, just like a short faced breed like the Chow Chow.
This head type is not correct but lots of people are fooled into thinking it is right because these dogs have big and impressive heads and they look appealing to people who do not know the finer points of the breed. They look cute like a ‘teddy bear’ but they are not correct!
There is a reason why the ACD head is supposed to be as the standard says and that is so it can work cattle without injury
The ACDs should have a strong head and broad skull for lots of brain room.
Even in Australia we have lots of judges who put up the wrong type of dogs.