Boxwood Poisoning in Cats

What makes the boxwood poisonous is a combination of three alkaloids, namely buxine, cyclobuxine and cylcoprotobuxine, and a butter-like oil. If enough of the plant is ingested, it can be fatal, although instances of this are rare. The plant is also extremely bitter to taste, which prevents most animals from eating large portions of it. In the past, boxwood was used in various veterinary treatments, but is no longer used due to the possible paralysis of the central nervous system that it can cause. It should be noted that the plant is still poisonous once it has been dried.

The boxwood, or box tree, is a decorative shrub often used as a hedge in North American gardens. It was introduced to the United States and is therefore not a native plant, but boxwood can be found growing all over the country. When ingested by cats, the leaves of this plant are poisonous. The level of toxicity depends on how much is eaten and the specific makeup of the cat itself. 

Whenever you suspect that your cat has eaten a poisonous substance, call an animal poison control center or veterinarian immediately. Symptoms to watch for include:

• Vomiting 
• Diarrhea
• General discomfort 
• Abdominal pain
• Intense gas
• Agitation
• Lethargy 
• Convulsions 
• Respiratory arrest
• Paralysis 

The only way for a cat to become poisoned from a boxwood is by ingestion of the plant. Outdoor cats may be more likely to be exposed to the shrub than indoor cats, as it is often used in people's gardens. Indoor cats may be exposed if trimmings of the boxwood are used in flower arrangements that are brought in the home.

If you witnessed your cat eating a plant but are unsure if it was a boxwood, bring a small cutting with you for identification at the veterinary clinic or animal hospital. Be prepared to answer questions about the environment where your cat is allowed to roam. The veterinarian will perform a physical examination to note all symptoms and differentiate a boxwood poisoning from other health issues that cause gastrointestinal distress in cats. Full blood work will be needed including a complete blood count and a biochemical profile to ensure no other problems exist in the body. 

There is no specific course of treatment for boxwood poisoning in cats. Care will be given to address the symptoms which have arisen and to help stabilize the animal if necessary.

Supportive Care 

If the cat's condition is severe, hospitalization will be required. Intravenous fluid administration may be needed to properly hydrate the cat after an extensive period of vomiting or diarrhea. All should be done to keep the cat comfortable to promote healing.

Induce Vomiting 

Making the cat vomit will expel all undigested materials in the cat's stomach. If you witnessed the cat eating a boxwood shrub, remove all of the leaf debris from its mouth.

Because most cats do not ingest large portions of the boxwood, it is very uncommon for boxwood poisoning to be fatal. Generally, no major side effects or long term issues develop from eating the plant. Most cats who have ingested boxwood go on to make a complete recovery after the initial sickness has passed.

The best way to prevent your cat from being poisoned by boxwood is to reduce or eliminate all possible contact with the plant. Keeping your cat indoors will shelter it from possible exposure to boxwood growing in your neighbors’ gardens. Closely inspect any plant arrangements that are given to you before bringing them into your home.