What is Ground Cherry Poisoning?
Physalis peruviana, more commonly known as Ground Cherry or Cape Gooseberry, is a fruit-bearing plant that protects each of its fruits with inflated paper-like calyx. Each part of this plant contains the glycoalkaloid solanine which, when eaten, will irritate the gastrointestinal system and may also attack the central nervous system in sufficient doses. This plant originates in Peru and Chile and is now found in many places around the world including Africa, Australia, and India.
Ground Cherry is in the same family as deadly nightshade and belladonna. Although it contains many of the same compounds, they are at somewhat lower concentrations.
Book First Walk Free!
Symptoms of Ground Cherry Poisoning in Horses
Symptoms of gastrointestinal distress are usually the first to present themselves, then, as the toxin is moved into the bloodstream, the signs of central nervous system involvement become more apparent.
- Abdominal pain
- Contact rash
- Dilated pupils
- Difficulty breathing
- Elevated heart rate
- Excessive salivation
- Loss of appetite
- Loss of coordination
- Progressive muscular weakness
- Rear leg paralysis
- Weak pulse
Ground Cherry, or Physalis peruviana, is not the only plant toxic to horses that that goes by the name cherry. Other cherries that are toxic to animals include:
- Prunus avium - This is the tree we usually think of like a cherry tree, and although the fruit is tasty, the leaves and cherry pits contain higher levels of a naturally occurring cyanogenic compound and can kill a horse quite quickly once it is ingested
- Prunus virginiana - Also known as a chokecherry, this shrub also contain the same cyanogenic compounds as their better-known cousins P. avium
- Solanum pseudocapsicum - Better known as the Jerusalem cherry, this plant also produces solanine.
Causes of Ground Cherry Poisoning in Horses
The toxicity of this flowering plant lies in the glycoalkaloid solanine that is located in every part of the plant except the ripened berries. This alkaloid is utilized by the plant as a natural defense against predators and is found in varying concentrations in several of the plants in the Solanaceae family, including eggplants and potatoes. Solanine disrupts the functioning of cell membranes and can cause cell death.
Diagnosis of Ground Cherry Poisoning in Horses
If you discover your equine consuming any part of the Ground Cherry plant or if you locate it in the pasture or around the stables, then the identification of the plant combined with the symptoms may be adequate to make a preliminary diagnosis of solanine poisoning. The equine veterinarian will collect information about the amount of plant material ingested and approximately how long ago this occurred, as these factors will help determine which treatment plant is the most effective for your horse.
Standard blood tests will rule out several other toxins and infections, and more specific tests may be able to detect the presence of the glycoalkaloids and possibly even the amount of solanine that is circulating in the blood. Drugs such as steroids, beta-blockers, and even some chemotherapy agents may negatively interact with the solanine found in the plant, so information about supplements and prescriptions that are being administered is also significant. If an elevated heart rate is detected an electrocardiogram may be employed.
Treatment of Ground Cherry Poisoning in Horses
If your horse is showing symptoms of solanine intoxication, your veterinarian will most likely recommend gastric irrigation in order to remove as much of the plant material from the digestive system as possible. Activated charcoal will typically be administered as well, in an attempt to soak up as much of the remaining toxic substance as possible before it dissolves into the horse’s bloodstream. Standard supportive measures generally include treatments such as intravenous fluid therapy to counteract dehydration and combinations of sugars and electrolytes to prevent any irregularities from taking hold.
Any tremors or convulsions that arise might be controlled with the administration of medications such as primidone, and if the patient is showing symptoms indicating the involvement of the heart, antiarrhythmic drugs such as quinidine may be utilized to regulate and slow the heart rate and the heart will be carefully monitored. It is also important to make sure that you eradicate any remaining Physalis peruviana from the pasture and stable areas so that the horse doesn’t ingest any further plant material.
Recovery of Ground Cherry Poisoning in Horses
The prognosis for animals that are poisoned by the Ground Cherry plant will depend on how much of the plant was ingested and how long it was between the consumption of the plant and the treatment of the patient. In most cases, horses recover from the poisoning rapidly, but in severe cases, it can be lethal. It is best to ensure that no ground cherry plants are growing close enough to your horse's daily environment for him to eat.