Yes, R.I.P. Fleas Extra is fully approved for the control of house dust mites. R.I.P. Fleas Extra contains two pyrethroids – permethrin and tetramethrin. Pyrethroids are effective acaricides, and therefore R.I.P. Fleas Extra will kill mites including house dust mites. House dust mites are one of the main allergens involved in allergic skin disease in dogs, and have also been implicated in asthma in people. Dead house dust mites are just as capable of causing an allergic reaction as live ones, so it is therefore essential that a vacuum cleaner with an appropriate filter is used regularly to remove dead house dust mites.