Fleas are ectoparasites that can cause dermatitis in dogs and can spread rapidly. Depending on the degree of flea infestation, a Veterinarian might suggest you oral medication and/or topical medication.
Next Steps
Consult your Veterinarian to assess the range of infestation and drugs to be used
Health Tips
Topical sprays, shampoos etc contains compounds that can be toxic to dogs as well as humans when ingested . Hence it is suggested to use them cautiously