Many fertilizers are salts made up of Nitrogen (N), Phosphorus (P) and Potassium (K) - and pure NPK fertilizers typically have low acute toxicity, although they can cause gastrointestinal upset if ingested in large quantities. Distributing these fertilizer granules evenly throughout your yard makes it difficult for pets to ingest large enough quantities to cause stomach upset, but if you notice diarrhea or vomiting and suspect your pet has eaten fertilizer, you should contact your vet. Spray-on products may be easier to ingest in large volume if your pet is prone to licking grass. With time and rain, your fertilizer should seep into the soil, where it is inaccessible to pets.
Iron toxicity in Fertilizer labeled to contain “XCU”:
“XCU” is a Nitrogen product that is labeled as a “slow-release” fertilizer. This form has a high Nitrogen content and added Iron. While it is unlikely that ingesting trace amounts of this fertilizer (i.e. licking a small amount off of the ground) would cause issues, if a large amount is ingested (i.e. fertilizer/soil eaten out of the bag), this may be cause for concern due to potential iron toxicosis. Some symptoms of iron toxicosis include gastrointestinal signs such vomiting and diarrhea, which may appear to resolve before severe symptoms (such as cardiac issues and liver failure) arise. If your pet develops any symptoms and you suspect that it is due to fertilizer ingestion, it is always essential to see a veterinarian - even if the symptoms appear to improve.
When possible, it is always best to keep pets away from freshly fertilized lawns.
This may include limiting access by using a leash or closely monitoring until it has rained and the fertilizer is no longer accessible. If a liquid product is applied, grass should be fully dry before allowing pets to have any contact with your lawn.
Herbicides, such 2,4-D and Roundup, have been shown to cause bladder cancer in pets and their use should be avoided or used with the same precaution as with fertilizer: don’t let pets into the area until after a good rainfall.
If you have questions or concerns, Poison Control can provide answers to a potential emergency, as well as make recommendations regarding treatment. The ASPCA poison control hotline can be reached at (888) 426-4435.