You can use a medicated shampoo that is suggested by vets in case the pet is liable to fleas and ticks. If you really like the person, though, and learn how to them better, you may consider doing this first before "hitting it" to see what strengthens. https://Ict.Wku.Ac.th/question/10-ways-to-a-long-life-and-great-health-back-towards-the-basics/