Indoor plants are a common household decoration. So common, in fact, that you should be aware of the danger they pose to your cat. Humans do not generally eat house plants, and urban (and suburban) residents buy their vegetables in markets, so it is easy to forget that animals still need to forage for roughage in the form of greenery.

Cats eat plants that grow in the wild for digestive purposes, to loosen undigested food (or hair) for regurgitation, and for self-treatment. Most cats are instinctively able to choose wisely when they have a variety of plants to choose from, and when they are given enough time outdoors. An indoor cat, however, may only have a variety of house plants to chew on, and this can be dangerous for the animal.

While not all indoor plants are fatally poisonous to your cat, some of them are still toxic enough to cause skin allergies and other reactions. Some plants have only certain parts that are toxic, while other plants are toxic throughout. Indoor plant poisoning, like any other case of poisoning, must be treated as an emergency condition.

Symptoms

Depending on the type of plant ingested, symptoms will vary, but some of the more common signs include:

• Vomiting
• Diarrhea
• Skin irritation
• Reddening and itching of the skin
• Respiratory, breathing problems

In severe cases, indoor plant poisoning can lead to convulsions, coma, and may even be fatal for cats.

Causes

Plant poisoning occurs when a cat ingests part of a toxic plant; even a small amount can cause health complications. Some of the most dangerous indoor plants for cats include the bird of paradise, ivy, nightshade, spider, umbrella, and asparagus fern. These highly toxic plants may affect the nervous system, kidneys, and/or heart, and are sometimes difficult to diagnose. Other common household  plants such as the chrysanthemum and poinsettia cause skin irritation.

Meanwhile, the peace lily, red princess, saddle leaf, tuberous begonia, heart leaf, parsley, and other common decorative plants contain oxalic acid. Categorized as a strong weak acid, oxalic acid can cause inflammation in the mouth, drooling, respiratory problems, and gastrointestinal upsets if a cat chews on or digests a plant containing oxalic acid.

Diagnosis

Diagnosis depends to a large extent on the background you provide your veterinarian. In order to accurately map your cat's health condition, you will need to list your cat's symptoms and how long they have been going on.

If you suspect that your cat has ingested toxic plant matter, take a specimen of the plant, along with a sample of vomit or regurgitated content, to the veterinarian when you take your cat in for care. There may be plant pieces in the vomit, or at the very least, your veterinarian will be able to check the vomit for evidence of other conditions, such as viral, bacterial, or parasitic infections  -- all of which may lead a cat to eat a plant.

Treatment

With your veterinarian's OK, apply emollient lotion to sooth the skin if skin irritation is present. A chemical reaction from combining lotion with plant toxin can worsen matters. Make sure that the lotion is safe for your cat, and for use with the particular toxin. You will need assistance holding the cat still while you apply any creams and ointments, or you can gently, firmly, restrain your cat with a collar.

For immediate first aid -- if you are positive that your cat has ingested a toxic plant -- try to induce vomiting with a simple hydrogen peroxide solution (one teaspoon per five pounds of body weight, with no more than three teaspoons given at once). This method should only be used if the plant has been ingested in the previous two hours, and should only be given three times, spaced apart at 10-minute intervals. Additionally, you should consult your veterinarian before proceeding, as inducing vomiting may be dangerous when certain plant toxins are involved.

If your cat has not vomited after the third dose, do not use it, or anything further, to try to induce vomiting. Also, discontinue the use of the hydrogen peroxide solution once your cat has vomited.

Administration of fluid therapy, antihistamine agents to decrease swelling or inflammation, and specific antidotes are dependent upon the type of plant poisoning, and are prescribed under your veterinarian's supervision. Fluid therapy is vital in stablizing the cat, and will continue until it is able to drink and eat on its own again.

A final word: do not induce vomiting on your cat if it is unconscious, is having trouble breathing, or is exhibiting signs of serious distress or shock. Keep your cat calm by wrapping it in a warm blanket if signs of impairment to the nervous system are evident. Many cities have a veterinary helpline or poison hot line to help you through the initial stages. As soon as you are able, take your cat to the nearest veterinary facility.

Living and Management

Make sure that you remove the plant that was the cause of the poisoning before returning your cat to the home environment. Allow your cat time to recover from the upset by giving it a calm and quiet space to get plenty of rest in. Consult with your veterinarian as to your cat's diet during the recovery period.

Prevention

Before deciding on indoor plants, develop your knowledge of the various plant species that are poisonous to cats, and avoid having such plants inside your home. Toxic plants that are accessible to your cat even for short periods, such as over the holidays, can result in an unintended but preventable tragedy.

If you are unsure about a plant's potential for toxicity, ask your veterinarian, or the local plant nursery, before bringing such plants into the home. Keep the number(s) for your local emergency veterinary helpline or emergency poison center where it can be easily accessed.