The treatment of a heartworm infestation takes several months, on average about three, but full recovery can take up to six months, depending on how severe the infestation was. (raisingrascal.com)
If a more severe infestation has occurred or if your dog has been diagnosed with flea allergy dermatitis, essential oil flea collars may not be effective. (organic-pet-digest.com)
If your pet has an especially severe infestation, or is acting sick in any way, bring him in for an exam. (vetdepot.com)