Johnson's Dog Flea Shampoo Johnson's Dog Flea Shampoo is an insecticidal shampoo to kill fleas etc. whilst beautifying your dog's coat. It contains natural biodegradable Pyrethrum & is suitable for all breeds of dogs & puppies over 12 weeks of age. Directions Wet coat thoroughly with warm water & apply the mixture all over the body. Massage well into coat, but use ginger tips around the head, taking care to avoid eyes, ears & mouth. Rinse very thoroughly, towel dry, then brush & comb. Keep pets warm after bathing.