Toxic mushrooms effect the liver and I would also suggest that if someone could inspect the outside area before letting the dog out and remove any mushrooms that suddenly appear after a heavy rain. This was suggested the the vet. Mushrooms are a fungus and if you want to remove them using fungicide.....you have keep the dog & children off the treatment area for a while. Read the label on the container well and wear old clothing, goggles, mask, gloves and hat. Refer to the label again for next application.