What is Carolina Horsenettle Poisoning?
Carolina horsenettle is commonly found in the southeastern United States. While the entire plant is toxic when ingested, the berries contain the highest potency of toxin. The leaves of the horsenettle plant contain prickly fibers making it undesirable to many animals, but ingestion does happen occasionally. Symptoms can range from mild, such as mouth pain and diarrhea, to severe, such as convulsions, hallucinations and even death. The only type of treatment for this type of poisoning is supportive. Prevention of ingestion is the ideal form of treatment.
Carolina horsenettle ingestion can lead to the death of your horse. If you believe he ingested a portion of this plant, contact your veterinarian immediately.
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Symptoms of Carolina Horsenettle Poisoning in Horses
Carolina horsenettle has low palatability so ingestion of this plant is not particularly common. However, if your horse does ingest it, symptoms he may experience includes:
- Mouth injury
- Esophageal injury
- Central nervous system symptom (pupil dilation, loss of muscular coordination, depression, hallucinations, convulsions)
- Gastrointestinal symptoms (diarrhea, decreased appetite, colic)
It is believed one to ten pounds of ingested horsenettle can be fatal to a horse.
The Carolina horsenettle is native to North America and is commonly found throughout the southeastern states. It is a member of the nightshade family and causes problems in grass pastures and hay fields. The leaves are glossy green on the upper surface and light green on the underside; both sides are hairy. Mature plants can grow up to three feet with flowers appearing in clusters. The flowers are white to pale violet and a unique star shape with yellow in the center. The fruit of the horsenettle are round yellow berries when mature.
Causes of Carolina Horsenettle Poisoning in Horses
Horsenettle contains a toxic chemical known as glycoalkaloids, or alkaloids and sugars. Depending on environmental conditions, the toxicity of the plant can vary. The stems and roots of the plant are the least toxic, the leaves more so, and the berries are considered the most toxic. Unripe berries contain the highest potency of the toxin.
Diagnosis of Carolina Horsenettle Poisoning in Horses
Diagnosis of horsenettle poisoning will come from a combination of the symptoms your horse is experiencing, his history, and any lab work results.
Your veterinarian will begin by performing a full physical exam on your horse. She will take note of any and all symptoms he is experiencing in order to come to a complete diagnosis. She will also collect a history from you as to what your horse has been eating, where he has been, when his symptoms began, and how quickly they have progressed. She may also ask to examine what he has been ingesting. If he has been out on pasture, she may ask you to take her out there so she can see what plants he has had access to recently.
She may also want to run some lab work to check how your horse’s organs are functioning. Blood work will begin with a complete blood count and chemistry panel. The results will indicate how the organs are filtering the toxin and what types of supportive therapies may be beneficial to begin. She may want to run more diagnostic lab work depending on the results of the initial tests.
Treatment of Carolina Horsenettle Poisoning in Horses
Unfortunately, there is no exact cure for Carolina horsenettle poisoning. The most promising treatment for your horse is supportive therapy. The symptoms your horse is experiencing will determine the course of supportive treatment the veterinarian will recommend.
She may choose to initiate a nutrition regimen in order to keep his digestive tract moving. She may also want to begin fluid therapy to prevent dehydration from developing. If your horse is experiencing some type of discomfort or inflammation from ingesting the plant, she may administer a pain medication or anti-inflammatory to help. In more severe cases with symptoms of CNS issues, a sedative may need to be administered to keep your horse from injuring himself, you, and veterinary staff.
Recovery of Carolina Horsenettle Poisoning in Horses
Severity of toxicity will determine which parts of the plant your horse ingested and how much. Toxicity can be mild to moderate or moderate to severe. The more serious the toxicity is, the more guarded the prognosis of recovery becomes. Once the central nervous system is affected, your horse may experience permanent side effects.
Plant management is an ideal form of prevention of Carolina horsenettle poisoning. If you know you have this plant in your field, you may need to buy clean hay to prevent your horse from ingesting it. While clipping will not control the horsenettle, it will slow the growth of the plant. The best way to eliminate it is to treat the areas where it appears before it spreads to a wider area.