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Your Happy Pet: Texas plants poisonous to your pet

Original Publication Date: April 7, 2014
By C. Sue Furman, Ph.D.

Spring has sprung, and many are visiting local garden centers to find the perfect plants to spruce up their home or garden. Unfortunately, a number of the most beautiful plants added for aesthetic value and several of the yummiest fruits and vegetables may be toxic if eaten by your pet.

Chrysanthemums and oleander are two toxic flowering plants common to this area. Many varieties of chrysanthemums, including some flowers not always thought of as a mum are poisonous. The common Gerbera daisy and its many daisy relatives are displayed side-by-side with typical chrysanthemums in most garden stores.

All are toxic to dogs, cats and horses, because the many varieties of chrysanthemums contain sesquiterpene, lactones, pyrethrins and other potential irritants. These toxins can cause vomiting, diarrhea, drooling, lack of coordination and dermatitis.

Lovely oleander, sometimes called rose bay, brightens many gardens this time of year. Despite its beauty, it, too is toxic to dogs, cats and horses. An animal may decide to nibble on a plant, as cases of poisoning have been reported at horse show venues where oleander was used to decorate.

However, poisoning is probably more frequent when a pet has access to fallen branches or trimmings from pruning. All parts of the oleander plant contain a highly toxic cardiac glycoside that is similar to digitoxin. Consumption of oleander can cause colic, diarrhea (possibly bloody), sweating, loss of coordination, shallow or difficulty breathing, muscle tremors and possibly death from cardiac failure.

It may be a surprise that some tasty fruits, such as apples and tomatoes, can be harmful to your pets. Parts of these plants are acceptable for our pets but some parts are not.

For example, the stems, leaves and seeds of apples contain cyanide that is toxic to dogs, cats and horses. It is particularly toxic if the leaves are in the process of wilting. Ingestion causes brick-red mucous membranes, dilated pupils, difficulty breathing, panting and shock.

The tomato is another culprit that is toxic to dogs, cats and horses. The vines, stems, leaves and unripe tomatoes of the plants growing in your garden pose a threat if eaten by your pet because they contain tomatine, an alkaloid related to atropine and solanine.

This potent toxin can cause lethargy, drooling, loss of appetite, vomiting, diarrhea or constipation, dilated pupils, drowsiness, behavioral changes, confusion, weakness and a slow heart rate.

Because tomatine is metabolized as the fruit ripens, vine-ripe red tomatoes that taste so good fresh from the garden are not likely to be harmful to your pet. Some veterinarians still do not recommend sharing them with your furry friends.

If you suspect or know that your pet has ingested any poisonous plant, immediately contact your veterinarian or the emergency clinic for care recommendations.

Have fun selecting plants for your garden, but bear in mind that care should be taken to keep some plants out of reach of your pets. For a comprehensive list and photos of pet-safe garden plants, visit the Animal Poison Control Center at

Sue Furman, Ph.D, has published two books and a DVD on canine massage and teaches classes in pet massage, acupressure, first aid and CPR. See her schedule and submit questions at