Resolution of neurologic signs presumed to be associated with hyperammonemia in 2 endurance horses.
Abstract: This case report describes 2 endurance horses with non-hepatic hyperammonemia. The animals were competing in a 160-km endurance competition in extreme heat conditions and were presented for obtundation. One of the horses also had evidence of blindness. The blood ammonia concentration was elevated (196 μmol/L and 249 μmol/L) and both horses improved following treatment with intravenous fluids and supportive care. These are the first documented cases of clinical signs presumed to be associated with hyperammonemia in endurance horses. Despite the severity of the clinical presentation, both horses made a full recovery. Key clinical message: Non-hepatic hyperammonemia should be considered as a potential cause of blindness and obtundation in competing endurance horses. Horses appear to respond well to treatment with intravenous fluids. Fin des signes neurologiques présumés être associés avec de l’hyperammoniémie chez deux chevaux d’endurance. Le présent rapport de cas décrit la situation de deux chevaux d’endurance avec une hyperammoniémie non-hépatique. Les animaux compétitionnaient dans une course d’endurance de 160 km dans des conditions de chaleur extrême et furent présentés pour confusion. Un des chevaux avait également des évidences de cécité. Les concentrations d’ammoniaque sanguin étaient élevées (196 μmol/L et 249 μmol/L) et les deux chevaux s’améliorèrent à la suite du traitement avec des fluides intraveineux et des soins de support. Ces cas représentent les premiers cas documentés de signes cliniques présumés être associés avec de l’hyperammoniémie chez des chevaux d’endurance. Malgré la sévérité de la présentation clinique, les deux chevaux ont récupéré complètement.Message clinique clé :L’hyperammoniémie non-hépatique devrait être considérée comme une cause potentielle de cécité et de confusion chez des chevaux d’endurance en compétition. Les chevaux semblent bien répondre à un traitement avec des fluides intraveineux.(Traduit par Dr Serge Messier).
Copyright and/or publishing rights held by the Canadian Veterinary Medical Association.
Publication Date: 2020-08-04 PubMed ID: 32741992PubMed Central: PMC7350152DOI: 10.4322/rbcv.2014.304Google Scholar: Lookup
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Summary
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The research article reports on two endurance horses that experienced neurologic symptoms, including confusion and blindness, due to non-hepatic hyperammonemia during an intense competition, but they fully recovered after intravenous fluid treatment and supportive care.
Background
This case report introduces two unique cases of non-hepatic hyperammonemia in endurance horses. Hyperammonemia is a condition where there is an excess amount of ammonia in the blood. It is a serious condition that may lead to a variety of health problems, most notably neurological disorders. The two affected horses were competing in a 160-km endurance competition under extreme heat conditions. They were presented for a lack of alertness, which is medically termed ‘obtundation.’
Clinical Observations
- One of the horses showed evidence of blindness, which was linked to the high concentration of ammonia in the blood.
- The horse’s blood ammonia concentration was tested and found to be significantly elevated, at 196 μmol/L and 249 μmol/L.
Treatment and Outcome
- Both horses were treated with intravenous fluids and given supportive care.
- Following the treatment, the health status of the horses improved, and they were able to participate again in endurance competitions.
- Despite the severity of the clinical presentation at the time of illness, both horses were able to make a full recovery.
Conclusion
The report concludes by highlighting the potential for non-hepatic hyperammonemia to cause blindness and obtundation in endurance horses. The condition could be related to extreme exertion during a competition, especially under high heat conditions. The study suggests that veterinarians and horse trainers should consider this when assessing horses that demonstrate neurologic signs under such conditions. Most importantly, the study found that horses responded well to treatment with intravenous fluids, which can save the lives of other horses suffering from the same condition.
Cite This Article
APA
Fielding CL, Magdesian KG, Mayer JR.
(2020).
Resolution of neurologic signs presumed to be associated with hyperammonemia in 2 endurance horses.
Can Vet J, 61(8), 860-864.
https://doi.org/10.4322/rbcv.2014.304 Publication
Researcher Affiliations
- Loomis Basin Equine Medical Center, 2973 Penryn Road, Penryn, California 95663, USA (Fielding, Mayer); Department of Medicine and Epidemiology, School of Veterinary Medicine, University of California, 1 Garrod Drive, Davis, California 95616, USA (Magdesian).
- Loomis Basin Equine Medical Center, 2973 Penryn Road, Penryn, California 95663, USA (Fielding, Mayer); Department of Medicine and Epidemiology, School of Veterinary Medicine, University of California, 1 Garrod Drive, Davis, California 95616, USA (Magdesian).
- Loomis Basin Equine Medical Center, 2973 Penryn Road, Penryn, California 95663, USA (Fielding, Mayer); Department of Medicine and Epidemiology, School of Veterinary Medicine, University of California, 1 Garrod Drive, Davis, California 95616, USA (Magdesian).
MeSH Terms
- Animals
- Horse Diseases
- Horses
- Hyperammonemia / diagnosis
- Hyperammonemia / veterinary
- Physical Conditioning, Animal
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