Peer-reviewed veterinary case report
Cynoglossum officinale (hound's-tongue)--a cause of pyrrolizidine alkaloid poisoning in horses.
- Journal:
- Journal of the American Veterinary Medical Association
- Year:
- 1984
- Authors:
- Knight, A P et al.
- Species:
- horse
Plain-English summary
Ten horses died after eating dried grass hay that contained a plant called hound's-tongue. The horses showed signs of weight loss, yellowing of the skin and eyes (icterus), sensitivity to sunlight (photosensitization), and brain problems related to liver damage (hepatic encephalopathy). When the livers of three of these horses were examined, they showed specific changes that are typical of poisoning from a type of toxin found in hound's-tongue. This plant has high levels of toxic substances that can harm the liver, as demonstrated by a pony that developed liver issues after being fed hound's-tongue for 20 days. Unfortunately, the outcome for the affected horses was fatal.
Abstract
The death of 10 horses was attributed to feeding dried grass hay containing hound's-tongue, Cynoglossum officinale. Affected horses developed weight loss, icterus, photosensitization, and hepatic encephalopathy. Histologic examination of the liver of 3 of the horses revealed megalocytosis, biliary hyperplasia, and fibrosis characteristic of pyrrolizidine alkaloid poisoning. Hound's-tongue was found to contain large quantities (0.6% to 2.1%, dry matter basis) of toxic pyrrolizidine alkaloids, which, when fed to a pony for 20 days, caused liver fibrosis and biliary hyperplasia.
Find similar cases for your pet
PetCaseFinder finds other peer-reviewed reports of pets with the same symptoms, plus a plain-English summary of what was tried across them.
Search related cases →Original publication: https://pubmed.ncbi.nlm.nih.gov/6490488/