Fertilizer ingestion is common with small animals, reports the ASPCA Animal Poison Control Center. In fact, calls about pets eating lawn and garden products were among the top 10 toxin calls to APCC in 2017.
Many fertilizers contain bone meal, fish meal or blood meal. Some even contain corn or corn cobs as a filler. Pets, especially dogs, find the contents of fertilizers quite tasty. Often they'll tear the bags open to ingest the contents.
Many pets also ingest fertilizers that were placed outside on the lawn or in flower beds, so owners need to be careful about not letting pets out when lawn treatments are being done, and make sure any preparation is completely dry before the pets go outside.
Most fertilizer ingestions cause mild GI upset and are not a huge concern, but some fertilizers contain herbicides or, rarely, insecticides.
Some pets will ingest such a large amount that food bloat or GDV are concerns. There can also be some muscle stiffness or soreness after ingestion. Finally, if the product is moldy, there may be tremors and seizures, if there were tremorgenic mycotoxins in the fertilizer.