Saponins take their name from the soapwort plant, the original source of soap. They are concentrated in varying amounts in plants as innocuous as alfalfa and as dangerous as deadly nightshade. The effect they have on your dog depends on the type of saponins, the amount he ingests, and his size and health. If you suspect your dog has chewed on a plant that contains saponins, contact your veterinarian right away.
So Many Saponins
Saponins are glucosides, or sugar-bonded sets of molecules, produced by a wide variety of plants. Saponins are known for their ability to foam like soap or detergent. Once in a dog's body, the sugar-bonded molecules that make up saponins separate, allowing the toxic or medicinal component to take effect. Not all saponins are dangerous for your dog. Some produce only mild reactions, while others can cause severe problems. Saponins are present in some dog foods, such as those that contain beet pulp, which do not normally cause any symptoms.
Common plants that are sources of saponins that pose a danger to your dog include aloe vera, English ivy -- but not most other types of ivy -- asparagus, yucca, golden pothos, warneckei dracaena, striped dracaena, pokeweed and Madagascar dragon tree. A number of ferns contain dangerous saponins, including the asparagus, plumusa, lace, emerald, emerald feather, shatavari and racemose ferns. Several types of holly, such as American, English, Oregon, European, winterberry, inkberry and Spanish thyme holly, also have dangerous saponins.
Symptoms of Dangerous Saponins
Most saponins affect your dog's digestive system and cause diarrhea, vomiting, cramping and pain. In some cases, diarrhea and vomit may also contain blood. Other common symptoms of poisoning from saponins includes dark urine, muscle twitches or spasms, lethargy, weight loss, drooling, head-shaking, seizures and abnormal heart rate. Regular contact with saponins can cause skin irritation, such as red bumps, flaky patches and hair loss.
The Good Side of Saponins
Like many chemicals found in plants, saponins can be beneficial in small amounts but dangerous in large ones. When extracted and given in carefully measured and controlled amounts, saponins can actually aid digestion, for example. In humans, they can help control cholesterol, while in some animals they kill intestinal parasites such as giardia. Saponins also serve in many commercial operations, such as mining, thanks to their detergent properties.