10-10-10 fertilizer is not harmful to dogs. However, using the fertilizer properly and keeping your dog away from the treated area until the fertilizer can soak into the ground is essential. The fertilizer can irritate your dog's skin and eyes if it comes into contact with them. The second factor to consider is the type of 10-10-10 fertilizer. Some fertilizer brands contain toxic dog ingredients, so checking the label before using them is important. As long as you keep dogs out of the area while you treat until your Fertilizer 10-10-10 has had time to dry or settle ultimately, it is safe for pets to return and resume normal activity.