Particularly important in small dome - headed breeds (Pomeranian, chihuahua etc.) would be congenital disease such as hydrocephalus, where abnormal fluid drainage from the brain creates damage. (marvistavet.com)
Depending on your project, a chip brush may be best — OR if looking for a heavier veil from the applied wash, perhaps Annie's small dome top brush. (thepurplepaintedlady.com)
It's actually a composite of several separate dome - shaped fluid pockets, with small domes sitting atop one larger dome. (sciencedaily.com)