Suspected marsh mallow (Malva parviflora) toxicosis in ponies-Case cluster including an asymptomatic survivor.
Abstract: There is limited published information on Malva parviflora toxicosis in horses. Four previously reported cases all resulted in death or euthanasia. The aim of this cluster investigation was to describe historical, clinical and clinicopathological findings of four ponies with suspected M. parviflora toxicosis and compare these to previously reported cases. Historical, clinical and clinicopathological findings were collated. Ponies were grazing pasture of approximately >90% M. parviflora. Pony 1 died rapidly without veterinary examination. Pony 2 was examined for prolonged recumbency attributed to severe myopathy and was subjected to euthanasia. Ponies 3 and 4 remained clinically normal. Pony 2 displayed markedly increased plasma creatine kinase (CK) and aspartate aminotransferase (AST) activities and cardiac troponin I (CTnI) concentration. Pony 3 had moderately increased plasma CK and AST activities and normal plasma CTnI concentration. Pony 4 had moderately increased plasma AST activity, with normal plasma CK activity and CTnI concentration. Plasma acyl carnitine profiles of Ponies 2 and 3 were consistent with previous suspected cases of equine M. parviflora toxicosis, but Pony 4's acyl carnitine profile was not different from healthy control horses. Pony 2 was typical of previously reported cases of M. parviflora toxicosis, but Pony 3 did not develop clinical signs despite a consistent acyl carnitine profile. Pony 4 likely did not have M. parviflora toxicosis. The findings of Pony 3 suggest M. parviflora toxicosis can be subclinical, and survival is possible in such cases. Further work is needed to determine the progression of disease from M. parviflora ingestion.
© 2025 The Author(s). Australian Veterinary Journal published by John Wiley & Sons Australia, Ltd on behalf of Australian Veterinary Association.
Publication Date: 2025-06-12 PubMed ID: 40506390DOI: 10.1111/avj.13455Google Scholar: Lookup
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Summary
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The research investigates instances of marsh mallow (Malva parviflora) toxicosis in ponies, finding some varied responses to the plant’s toxicity and potentially subclinical cases which may not present obvious symptoms but could still be harmful.
Overview of the Research
- This research focuses on the toxic effects of the marsh mallow plant (Malva parviflora) on ponies. Ponies are known to react to ingestion of this plant, but the responses can be varied, and there’s limited detailed information on this topic.
- Researchers aimed to provide a more comprehensive report on M. parviflora toxicosis, comparing new cases with those previously recorded.
Methodology and Case Details
- The study consists of detailed analysis of four cases of ponies that consumed pasture with a high proportion of M. parviflora.
- One pony died quickly without any opportunity for veterinary examination. A second pony had to be euthanized due to severe myopathy.
- The remaining two ponies did not show any clinical signs of M. parviflora toxicosis. These were particularly significant as they didn’t align with the expected results observed in previous cases.
Results and Findings
- Blood analyses showed notable increases in plasma creatine kinase (CK), aspartate aminotransferase (AST) activities, and cardiac troponin I (CTnI) concentration for the second pony, who was euthanized. The other two ponies had moderately increased plasma CK and AST activities, but normal plasma CTnI concentration.
- The readings of plasma acyl carnitine, an indicator of equine M. parviflora toxicosis, were consistent for Ponies 2 and 3, however, the same did not hold true for Pony 4, whose readings resembled those seen in healthy horses. This implies that consumption of M. parviflora does not always result in toxicosis.
Key Takeaways and Suggestions for Further Research
- The study discovered some instances of subclinical M. parviflora toxicosis where a pony can be affected by the plant without displaying typical symptoms.
- The researchers propose further investigation into the disease progression from M. parviflora ingestion, as the understandings of this are currently incomplete. This could add significantly to the field of veterinary medicine, especially equine health, by helping to predict and manage the risks associated with ponies feeding on M. parviflora.
Cite This Article
APA
Bauquier J, Takahashi C, Rosales C, Pitt J.
(2025).
Suspected marsh mallow (Malva parviflora) toxicosis in ponies-Case cluster including an asymptomatic survivor.
Aust Vet J.
https://doi.org/10.1111/avj.13455 Publication
Researcher Affiliations
- Melbourne Veterinary School, University of Melbourne, Werribee, Victoria, Canada.
- Melbourne Veterinary School, University of Melbourne, Werribee, Victoria, Canada.
- Barwon Equine Hospital, Moolap, Victoria, Australia.
- Victorian Clinical Genetics Services, Royal Children's Hospital, Melbourne, Victoria, Australia.
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