When bitten by a cow fly, you first need to rinse the wound, then disinfect it locally, and then apply or take oral medication as prescribed by your doctor for symptomatic treatment. Cow flies belong to the insect class, the bite is very easy to cause insect bite dermatitis, so when bitten by a cow fly, do not be careless, immediately use running water to rinse the wound, and then disinfected with iodophor, hydrogen peroxide or alcohol, and then you should go to the hospital, under the guidance of the doctor’s topical or internal drug treatment. Usually, in order to alleviate the insect bite reaction, the principle of internal and external medication is anti-allergic and anti-inflammatory. Topical topical dexamethasone ointment, benadryl ointment or oral loratadine, paracetamol and other medications can be applied as prescribed by the doctor. It is important to note that you should avoid scratching the bitten area to prevent secondary infection of the wound. In conclusion, if you are bitten by a bull fly, you must take appropriate measures to deal with it and seek medical treatment in time.