Lawn fertilizers can hurt dogs, according to Garden Guides. Lawn fertilizers carry nitrogen, phosphate and potassium, all of which cause irritation to a dog's stomach when ingested. A study conducted by Purdue University shows that the ingestion of insecticides and herbicides fosters a higher risk of bladder cancer in canines.
Garden Guides states that lawn fertilizers cause skin irritation and diarrhea in dogs. An article from SFGate highlights other visible symptoms of canine fertilizer poisoning, such as vomiting and seizures. Organic fertilizer also contains metals, pathogens and other forms of waste that irritate a dog's digestive tract.
In the case of liquid fertilizer, the SFGate states that dogs should be kept off of lawns until the grass is visibly dry. For granular fertilizer, keeping dogs away from grass for 24 hours allows enough time for the soil to absorb the pellets.
There are certain fertilizers marketed as pet-friendly, according to LiquidFertilizerOrganic.com. The website recommends choosing a brand of fertilizer that contains no insecticides and herbicides, along with checking the label to ensure the product is dog-friendly. It is important for dog owners to avoid fertilizers containing harmful chemicals, such as chloroethane, which is a carcinogenic agent, and organophosphates, which can lead to labored breathing, hyperthermia and death in dogs.