Abortions in Thoroughbred mares associated with consumption of bulbosus buttercups (Ranunculus bulbosus L).

This research outlines a case study of Thoroughbred horses in Kentucky, whose weight loss, miscarriages and severe physiological conditions were eventually linked to the consumption of the toxic buttercup plant, Ranunculus bulbosus L. This report emphasizes the importance of on-site epidemiological examination to diagnose such conditions and suggests the plant’s toxicity may induce symptoms that mimic gastrointestinal diseases in herbivores.

Research Context and Objective

• The research was triggered by unexplained weight loss and gradual emaciation in a group of Thoroughbred horses on a farm in Kentucky, where ample grain and hay supplements were being provided.
• It was observed that the buttercup plant, Ranunculus bulbosus L, was excessively present in all pastures and paddocks of the farm.
• This unusual condition of weight loss was reported in all horses, particularly evident in lactating mares and their foals. Additionally, the miscarriage of seven mares, which were initially found pregnant, was also reported.

Findings

• Two of the two-year-old female horses exhibited signs like severe diarrhea, incoordination, recumbency, and paralysis, and had to be euthanized.
• Necropsies of these horses displayed ulcer and erosion incidences in their stomach and large intestine, a condition that was deemed consistent with buttercup toxicosis.
• As an intervention, the horses were removed from the buttercup-occupied pastures and transferred to a farm free of the weed.
• Evidently, all the horses recovered smoothly, and the health issues were resolved post the transfer. Also, the mares that had previously miscarried could conceive successfully in the next breeding season.

Conclusions and Significance

• Given the evidence, it was concluded that the buttercup plant is toxic for all types of livestock. The associated clinical signs due to buttercup toxicosis could imitate other disease syndromes that affect the herbivores’ gastrointestinal tract.
• This research emphasizes the importance of on-site epidemiological inquiries in diagnosing such conditions. Although the consumption of buttercups has been priorly related to abortions in cattle, this is the first-known description of the same in horses.