Homeowners with dogs (or other pets that spend time in the yard) should use organic lawn fertilizer for two reasons.  First of all, organic fertilizers are non-toxic. Your pets will be perfectly safe if they nibble on the treated grass, even right after you fertilize.  Second, most organic fertilizers have a low nitrogen content. You have to be extra careful about applying nitrogen to your lawn if you have dogs because when your dog pees in the grass, they add even more nitrogen to the soil. The combination of a high-nitrogen fertilizer and dog urine often results in fertilizer burn and brown patches in the lawn.