Cool cotton will keep the sun off your pooch's head and protect the eyes and nose. If this proves too much of a problem.....turn it backwards and give them total street cred!
As a guideline -
XS suits chihuahua,
S suits small maltese, pomeranians,
S/M suits malt/shih tzu, cavaliers, mini schnauzer,
M suits schnauzer, cocker spaniel, cavoodles,
L suits staffie, boxer, small labradors
XL suits golden retriever, labradors,
