This is a lovely Blue Heeler - a breed from Australia originally, which was created by breeding herding dogs with domesticated dingoes.
It was painted in two passes. I put the background in with straight, black acrylic paint and also used splurges of black acrylic to indicate the nose and edges of the ears. Once this was thoroughly dry, I worked the eyes and the yellow ochre fur.
He looked distinctly odd at this point, but I let the paint tack up for 3 or 4 hours whilst I started on a separate painting. Then the rest of him was completed using black, ultramarine and white.
To achieve the 'speckled' effect, particularly on his muzzle, it is important to apply the lightest possible brush pressure. Any accidental mixing - creating a very unconvincing sky-blue colour in the case of this dog - needs wiping off with cotton buds before re-applying.
I have learnt the hard way that when overlaying light fur on to dark fur, any over-zealousness with the brush cannot be corrected: the mistake must be wiped off and re-painted.