Stringhalt in Brazilian horses caused by Hypochaeris radicata.
Abstract: Two outbreaks of Hypochaeris radicata-induced Australian stringhalt involving two farms and seven horses from southern Brazil are reported here. Subsequently, the disease was experimentally reproduced in a feeding trial with one colt fed H. radicata from the suspect paddocks. Fresh H. radicata was fed to the experimental animal for 50 days at an average daily dosage of 9.8 kg. Initially, the plant was collected from the paddock where the clinical disease occurred and was fed for 19 consecutive days producing mild clinical signs. However, on days 20-23 fresh plant was collected from a neighboring farm where the disease had not been reported and fed to the colt at which time the colt appeared to recover. Therefore, plant collections from the original suspect paddock resumed and feeding trials continued with clinical signs reoccurring by day 36, and increasing in intensity from days 43-50 after which plant administration was stopped. Within 15 days after ending the feeding trial with H. radicata, the colt appeared to have recovered. This experimental reproduction of stringhalt in a single colt fed H. radicata demonstrated that the two outbreaks of the disease resulted from this plant. Interestingly, the change in location for collection of plant material 19 days into the treatment, and the subsequent recovery of the colt, would suggest that plant material may differ in toxicity depending on location.
Publication Date: 2008-05-29 PubMed ID: 18617211DOI: 10.1016/j.toxicon.2008.04.164Google Scholar: Lookup
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- Journal Article
- Research Support
- Non-U.S. Gov't
Summary
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This research article discusses two outbreaks of Australian stringhalt, a disease in horses caused by the plant Hypochaeris radicata, in southern Brazil, and the successful reproduction of the disease in a colt through a controlled feeding trial.
Experimentation and Observations
- The study focuses on two separate stringhalt outbreaks in southern Brazil that affected seven horses across two farms.
- Stringhalt, an abnormal gait in horses, can be caused by consumption of the plant Hypochaeris radicata.
- The researchers decided to test their hypothesis that H. radicata was the cause of the outbreaks by conducting a feeding trial using one colt.
- For 50 days, the colt was fed an average daily dosage of 9.8 kg of fresh H. radicata sourced from the paddocks where the clinical disease had occurred.
- After 19 days of intake from one location, mild clinical signs began to show, indicating the onset of stringhalt.
Change of Plant Source and Observations
- Between days 20 and 23 of the experiment, the source of the H. radicata given to the colt was changed to a neighboring farm, where no cases of stringhalt had been reported.
- The change of food source seemed to have a positive effect on the colt, its clinical signs of stringhalt appearing to recede.
- In response to this unexpected recovery, researchers resumed feeding the colt H. radicata from the initial, suspect paddock.
Return to Original Plant Source and Observations
- The return to the original plant source led to a resurgence of stringhalt symptoms in the colt on day 36 of the experiment.
- The severity of the colt’s symptoms increased from day 43 to 50, after which researchers stopped feeding the H. radicata to the colt.
- Within 15 days of ending the feeding trial, the colt’s health seemed to return to normal.
Conclusions Drawn from Findings
- These findings provided strong evidence that the stringhalt outbreaks in southern Brazil were indeed caused by the horses’ intake of H. radicata.
- The varying effects of the plant gathered from different locations suggested that H. radicata’s toxicity may vary based on where it is grown.
Cite This Article
APA
Araújo JA, Curcio B, Alda J, Medeiros RM, Riet-Correa F.
(2008).
Stringhalt in Brazilian horses caused by Hypochaeris radicata.
Toxicon, 52(1), 190-193.
https://doi.org/10.1016/j.toxicon.2008.04.164 Publication
Researcher Affiliations
- Hospital Veterinário, CSTR, Universidade Federal de Campina Grande, Centro de Saude e Tecnologia Rural, Campus de Patos, 58700-000 Patos, Paraíba, Brazil.
MeSH Terms
- Animals
- Asteraceae / poisoning
- Disease Outbreaks / veterinary
- Horse Diseases / epidemiology
- Horse Diseases / etiology
- Horses
- Neuromuscular Diseases / epidemiology
- Neuromuscular Diseases / etiology
- Neuromuscular Diseases / veterinary
Citations
This article has been cited 2 times.- Carvalho KS, de Barros CSL, Mendonça FS, Machado M, Riet-Correa F. Diseases of the nervous system of equids in Brazil: a review. J Vet Diagn Invest 2025 Sep;37(5):729-752.
- Riet-Correa F, Machado M, Micheloud JF. Plants causing poisoning outbreaks of livestock in South America: A review. Toxicon X 2023 Mar;17:100150.
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