What is European Bittersweet Poisoning?
European bittersweet (Solanum dulcamara) is a perennial vine in the Solanum genus of plants, which also includes deadly nightshade, belladonna, and eggplant. It is also known as bittersweet nightshade and blue bindweed, and it contains many of the same toxins that it’s deadlier relatives do although at lower concentrations. Ingesting this plant is rarely fatal when treated but it does cause alarming symptoms, and medical intervention gives your pet the best chance at a full recovery.
European bittersweet is in the same family as deadly nightshade and belladonna. Although it contains many of the same compounds, they are at somewhat lower concentrations.
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Symptoms of European Bittersweet Poisoning in Dogs
Gastrointestinal symptoms are usually the first to arise, then, as the toxin is introduced into the bloodstream, the signs of involvement of the central nervous system become more apparent.
- Abdominal pain
- Contact rash
- Dilated pupils
- Difficulty breathing
- Elevated heart rate
- Excessive drooling
- Loss of appetite
- Loss of coordination
- Progressive muscular weakness
- Rear leg paralysis
- Weak pulse
The European bittersweet plant, in the Solanum family of plants, should not be confused with the American bittersweet, also known as false bittersweet. American bittersweet, or Celastrus scandens, is native to North America and was used historically for a variety of medical ailments by Native Americans. Both types of “bittersweet” are woody vines that exhibit attractive red or orange berries on their branches in the fall and are similar in appearance. They are from very different plant families.
Although the American version of bittersweet is also mildly to moderately toxic, the gastrointestinal symptoms are more pronounced, and the involvement of the central nervous system is less frequent. Very little research has been done on the specific compounds responsible for the toxicity of the American bittersweet plant, although glycosides and saponins are suspected sources.
Causes of European Bittersweet Poisoning in Dogs
The cause of the noxiousness of this plant lies in the glycoalkaloid solanine that is present in all parts of the plant. This compound is used by the plant as a natural defense against predators and can be found in varying concentrations in many of the plants in the Solanaceae family, including potato plants and eggplant. This glycoalkaloid disrupts the functioning of cell membranes and can cause cell death.
Diagnosis of European Bittersweet Poisoning in Dogs
If you discover your pet consuming any part of the European bittersweet plant, the identification of the plant may be sufficient to make an initial diagnosis of solanine poisoning. Your dog’s doctor will gather information regarding the amount of plant material ingested, how long ago this occurred, and what parts of the plant were eaten, as these factors will help determine the most effective treatment plan for your animal. If the ingestion of the item was not witnessed, the symptoms would prompt your veterinarian to take note of any opportunistic eating that was observed or suspected.
Drugs such as beta-blockers, steroids, and some chemotherapy agents may interact negatively with the glycosides found in the plant, so information about prescriptions and supplements is also noteworthy. There are blood tests available to detect the glycosides, as well as to monitor the levels of solanine in the system. However, the cost of these methods generally limits their availability for the purposes of veterinary diagnosis.
Treatment of European Bittersweet Poisoning in Dogs
If the amount of the plant ingested was small, and it occurred within a short period of time, your veterinarian might choose to instruct you on how to safely induce vomiting in your pet. If this is the case, home care may be sufficient in easing your dog’s discomfort, but if larger amounts were consumed, or if signs of nervous system involvement are showing you may need to transport your dog to the nearest clinic. Once at the clinic, gastric lavage may be done to remove as much of the plant material from the stomach as possible, and activated charcoal will generally be administered in an attempt to soak up as many of the toxic compounds as possible before they dissolve into the bloodstream.
Tremors and convulsions may be controlled with diazepam. When the presenting symptoms indicate the involvement of the heart, antiarrhythmic drugs such as atropine sulfate, procainamide or lidocaine may be utilized, and the heart will be carefully monitored. General supportive measures are likely to include IV fluids for dehydration and combinations of sugars and electrolytes to counteract any irregularities.
Recovery of European Bittersweet Poisoning in Dogs
Providing a quiet, calm setting for your pet to return home to will help speed recovery. Avoiding further stress to the heart is of particular importance when the heart is involved due to the glycosides present in the plant. Patients that are recovering from anesthesia given for a gastric lavage may have coordination difficulties at first, and are often confused and disoriented even in familiar surroundings. Isolation from other pets and from children may be wise until both the toxins and medication have fully cleared your companion’s system.