Native to Europe, the foxglove was introduced to North America where it has escaped cultivation and now is widespread in the northwest. It prefers disturbed rich soils growing along roadsides, fences. It is commonly grown as a garden plant.
Animals Affected
Horses, cattle, deer. All animals are susceptible.
Foxglove
Toxic Principle
Several cardiac glycosides, the most important of which are digoxin, digitoxin and their genins, are found in all parts of the plant. Livestock are infrequently poisoned, but will eat the plant occasionally either fresh or in hay. The plant remains toxic when dried
Description
Perennial herb growing 1-2 meters tall with alternate toothed, hairy, basal leaves. The characteristic purple or white tubular pendant flowers have conspicuous spots or streaks on the inside bottom surface of the flower
Other common species introduced into North America include Digitalis lanata (Grecian foxglove), D.lutea (straw foxglove) Many hybrids have been developed
Gastrointestinal
Diarrhea
Treatment
Induction of vomiting, gastric lavage, or administration of activated charcoal is appropriate for removing the plant and preventing further absorption of the toxins. Cathartics may also be used to help eliminate the plant rapidly from the digestive system. Serum potassium levels should be closely monitored and appropriate intravenous fluid therapy initiated as necessary. Phenytoin, as an anti-arrhythmic drug effective against supraventricular and ventricular arrhythmias can be used as necessary. The use of commercially available digitalis-specific antibody (Digibind - Burroughs Wellcome) may be a beneficial in counteracting the effects of the cardenolides.
Cardiovascular system
A variety of cardiac arrthymias and heart block including first and second degree heart block and ventricular tachycardia may be encountered with cardiac glycoside poisoning. Rapid, weak, irregular pulse. Sudden death may be the only finding in acute poisoning.
Respiratory System
Rapid breathing.
Diagnosis
Blood for detection of digitalis glycosides should be submitted to a laboratory for analysis