Fertilizer poisoning in cats tends to increase in the spring when homeowners begin to think about their lawns and gardens. They want to prepare the soil with fertilizer to provide the best growing medium possible. However, fertilizer poisoning appears on several lists of the top ten feline poisons so it's a good idea to learn more about it. 

Organic and natural fertilizers pose no threat to felines unless they have become moldy. The basic ingredients in chemical fertilizers are safe, too. Nitrogen, phosphorous, and potassium occur naturally in soil. It’s when other chemicals like insecticides, herbicides, and fungicides are added, along with large quantities of minerals like copper, manganese, iron, and others, that fertilizer becomes dangerous for cats. Some fertilizers contain bone or blood meal, or corn, as well. In small quantities, these added ingredients may only cause mild gastrointestinal problems, but they become problematic if a cat eats a lot of fertilizer.

Fertilizer poisoning should prompt a call to your veterinarian, and invariably a visit. Ingestion of large amounts of the substance is considered a pet emergency, but even smaller amounts should not be ignored.

Fertilizer poisoning symptoms can be widespread and affect various parts of a cat’s body. They can include:

Cats can become poisoned by fertilizer in a number of ways. The most direct way occurs in outdoor cats, but indoor cats are vulnerable as well. The common causes of fertilizer poisoning in cats include:

Since some symptoms of fertilizer poisoning can look like other ailments, consultation with a veterinarian is critical to diagnose the condition. The vet will ask about any contact the cat may have had with any toxins, including fertilizers, and an estimate of how much they may have ingested. It’s a good idea to bring along a list of the ingredients of the fertilizer, with their concentrations which you can find on the bag or bottle. If you can’t bring in the actual packaging, a picture taken on a smartphone is the next best thing.

A physical examination can pinpoint symptoms such as muscle stiffness and pain, and help determine the severity of the condition. Blood may be collected that will show concentrations of minerals and other substances, along with abnormal amounts of blood constituents like cells and platelets.

For a cat who has ingested fertilizer, treatment focuses largely on alleviating symptoms and providing overall support. A one- or two-day hospitalization may be necessary to monitor the feline until they show signs that the toxins have dissipated. All of the treatment methods listed are minimally invasive, and carry relatively low risk. Treatment measures may include:

In some cases, especially if a large quantity of fertilizer has been ingested, the veterinarian may order xylazine to cause vomiting and empty the stomach of remaining fertilizer. If the cat is already vomiting when they are brought in, the recommendation may be to allow them to empty their stomach themselves, withholding food and water for an hour, then allowing sips of water. If the cat is vomiting continuously, an antiemetic like maropitant or ondansetron may be helpful. 

Activated charcoal is generally not used for fertilizer poisoning because it binds poorly with minerals and will be of little use to counteract them. Other ingredients in the fertilizer, however, may be removed by the charcoal, so it may depend on what kind of fertilizer was ingested. 

GI protectants such as sucralfate, omeprazole, and famotidine may be administered to help calm the stomach down by decreasing the amount of acid being produced.

Metronidazole is used if the cat is experiencing bloody diarrhea. Bloat, if present, will be treated with simethicone.

In cases where the cat has ingested fertilizer with a large amount of added iron, Milk of Magnesia may be prescribed. The magnesium oxide present in MOM binds with iron molecules so they can be removed from the cat’s system through the GI tract.

Opioids may be administered for muscle or abdominal pain. Opioids are preferable to non-steroidal anti-inflammatory drugs because NSAIDs may cause or worsen stomach irritation, and can even cause gastric bleeding. A muscle relaxant such as methocarbamol may also be given to relieve painful muscle stiffness or twitching.

To replace fluids lost in vomiting, prevent dehydration, and help flush any remaining toxins out of the cat’s system, IV fluids will be administered while they’re in the hospital. The vet will judge when it’s okay to begin offering water in small amounts again once the kitty goes home.

When you’re able to take your cat home, your veterinarian will have instructions and recommendations for ensuring the feline is completely clear of toxins. It’s important to schedule and keep follow-up appointments so the vet can monitor the efficacy of their treatment, and watch out for the recurrence of symptoms or complications like pancreatitis.

Recommended measures to prevent subsequent fertilizer poisoning involve putting fertilizers and other garden chemicals out of a cat’s reach and in a container they can’t get into. If your feline goes outdoors, be sure the newly spread fertilizer has dried before letting them roam, generally for 24 to 72 hours. It’s best to wait until after a rain shower has helped soak the fertilizer into the soil, then dried. 

If the cat is an indoor cat, remove your gardening shoes and gloves outside to avoid bringing toxins inside the house. If you have a dog and they go outside, wipe them down when they come in to prevent your cat from grooming them and ingesting toxins.

Organic and natural fertilizers are available and won’t harm pets. They’re also effective without needing added chemicals and minerals. If it’s possible, they’re a great option for people with both gardens and pets.

Got more questions about fertilizer poisoning in cats? Chat with a veterinary professional today to get the lowdown on this dangerous condition.

Average cost of treating fertilizer poisoning in cats: $500 - $1,000