Water Hyacinth Poisoning in Cats

The exact toxins in the water hyacinth plant are unknown. Poisoning from the water hyacinth plant is usually not serious or life-threatening. However, owners can never know the full extent of poisoning without the help of a veterinary professional. Plant poisoning can also cause discomfort for your cat, so you should take it to the vet right away if you suspect it has ingested the water hyacinth.

The water hyacinth – also known as the Eichhornia crassipes – is a type of garden plant that is toxic to domestic pets, including dogs, cats, and horses. Ironically, although this plant is toxic to horses when ingested, the flowers of the water hyacinth have been used to make a tonic for soothing horses’ skin. As the name suggests, these plants usually grow in the water. The water hyacinth is a member of the Pontederiaceae family. You can recognize the water hyacinth by its thin, light purple petals and broad, waxy leaves.

Symptoms of water hyacinth poisoning will normally appear quickly following ingestion and are usually moderate. If you notice any of the following symptoms, take your cat to the vet immediately.

• Vomiting
• Drooling
• Loss of appetite
• Rapid heart rate
• Difficult or shallow breathing

The cause of water hyacinth poisoning is ingestion of the plant. Since cats have a known aversion to water, it is highly unlikely they will ingest this water-dwelling plant, especially in large quantities. However, if your cat does ingest it, you should take it to the vet immediately. While the exact toxic principles of the water hyacinth are unknown, ingestion can cause discomfort for your cat, so you should seek immediate veterinary attention even if your cat’s symptoms appear to be mild.

If you grew the water hyacinth in your garden or pond, you should take a sample of it with you when you go to the vet. Tell your vet how long your cat has been experiencing symptoms, and provide them with an estimate of how much of the water hyacinth your cat ingested, if possible.

Presentation of symptoms, in addition to blood and urine tests, is generally sufficient to confirm cases of plant poisoning. Your vet may recommend other tests based on your cat’s symptoms.

Your vet will treat water hyacinth poisoning using the same treatment methods for other mild cases of plant poisoning. Your vet may administer activated charcoal to absorb any undigested toxins in the stomach. Intravenous fluid and/or nutritional therapy may also be recommended, particularly in cats suffering from dehydration or significant loss of appetite. If persistent vomiting has occurred, your vet may administer antiemetic drugs to control the vomiting.

If large quantities of the plant have been ingested, your vet will recommend treatment based on your cat’s symptoms. Other treatment methods may be recommended based on your cat’s symptoms. Dietary changes may be recommended in all cases of water hyacinth poisoning; if your cat has a habit of ingesting plants, this could be an indication that it is not receiving adequate nutrition.

Recovery and prognosis following most mild cases of plant poisoning generally range from good to excellent as long as the poisoning is diagnosed and treated quickly. Cats presenting mild cases of plant poisoning usually make a full recovery within 24 hours following treatment. In the extremely rare cases of severe water hyacinth poisoning, the prognosis may be more guarded based on symptoms.

For mild cases of plant poisoning, follow-up appointments usually aren’t necessary. If your cat has ingested large quantities of the water hyacinth and has experienced organ damage or severe symptoms, your vet may schedule follow-up appointments as needed to monitor organ function.

It is likely that your cat will have encountered the water hyacinth while outdoors, since the plant grows in water. If this is the case, you may want to limit or monitor your cat while it is outdoors to protect it against future cases of poisoning. If you are growing the water hyacinth in a small water garden or pond, it may be necessary to remove it. 

Although most cats do not usually enjoy going near the water, do not assume your cat will not try to reach a toxic plant just because of its location. Cats are also known for their curiosity, and may attempt to eat a plant if it looks appealing to them. Err on the side of caution, and research plants before making any purchases to ensure they do not contain substances that are toxic for your cat.