Regional pulmonary veno-occlusion: a newly identified lesion of equine exercise-induced pulmonary hemorrhage.
Abstract: Exercise-induced pulmonary hemorrhage (EIPH) is common in horses following intense exertion, occurring in up to 75% of racing Thoroughbreds and Standardbreds. In spite of this, the pathogenesis of EIPH is poorly understood. In 7 racing Thoroughbred horses with EIPH, 6 sections were collected from the left and right lung, representing the cranial, middle, and caudal region of the dorsal and ventral lung (84 sites total). Grossly, both right and left lungs had numerous dark brown to blue-black foci along the caudodorsal visceral pleura. Tissue sections were stained with hematoxylin-eosin, Masson's trichrome, and Prussian blue. Verhoeff Van Gieson and immunohistochemistry for alpha-smooth muscle actin were used to assess the pulmonary vasculature. Histologic scores (HS = 0-3) were assigned to each region/slide for the presence and severity of 5 findings: interstitial fibrosis, hemosiderin accumulation, pleural/interlobular septal thickness, arterial and venous wall thickness, and evidence of angiogenesis (maximum cumulative HS = 15). Thirty-nine of the 84 (46%) sections were histologically normal (HS = 0); 33/84 (39%) were mildly to moderately affected, with small amounts of hemosiderin and fibrosis (HS = 1-9) while 12/84 (14%), primarily from the dorsocaudal lung, had severe vascular remodeling, fibrosis, and hemosiderin accumulation (HS = 10-15). In the latter, veno-occlusive remodeling of the intralobular veins colocalized with hemosiderosis, fibrosis, hypertrophy of vessels within the pleura, and interlobular septa and bronchial neovascularization. We propose that regional veno-occlusive remodeling, especially within the caudodorsal lung fields, contributes to the pathogenesis of EIPH, with the venous remodeling leading to regional vascular congestion and hemorrhage, hemosiderin accumulation, fibrosis, and bronchial angiogenesis.
Publication Date: 2008-05-20 PubMed ID: 18487488DOI: 10.1354/vp.45-3-316Google Scholar: Lookup
The Equine Research Bank provides access to a large database of publicly available scientific literature. Inclusion in the Research Bank does not imply endorsement of study methods or findings by Mad Barn.
- Journal Article
Summary
This research summary has been generated with artificial intelligence and may contain errors and omissions. Refer to the original study to confirm details provided. Submit correction.
The research paper investigates the causes of exercise-induced pulmonary hemorrhage (EIPH) in thoroughbred racehorses. The study reveals a new lesion associated with EIPH, termed as regional veno-occlusive remodeling, and suggests that it could contribute to the development of EIPH, leading to issues like vascular congestion, hemorrhage, fibrosis, and bronchial angiogenesis.
Study Background and Methodology
- Exercise-induced pulmonary hemorrhage (EIPH) is a condition that affects thoroughbred racing horses after intense physical activity. Despite its prevalence, with up to 75% of racing Thoroughbreds and Standardbreds being affected, the pathogenesis of EIPH remains uncertain.
- The study examined seven Thoroughbred horses with EIPH. From each horse’s lungs, six sections were collected, covering both the left and right lung from different regions of the dorsal and ventral lung, totaling 84 sites.
- The lungs had numerous dark brown to blue-black spots, primarily along the caudodorsal visceral pleura. Histologic scores were assigned based on the presence and severity of five observed features: interstitial fibrosis, hemosiderin accumulation, thickness of pleural/interlobular septal, and arterial and venous wall, and evidence of angiogenesis.
Findings and Interpretation
- Out of the 84 sections, almost half (46%) were histologically normal. About 39% were mildly to moderately affected, exhibiting small amounts of hemosiderin and fibrosis. The remaining 14% had severe symptoms, including vascular remodeling, fibrosis, and hemosiderin accumulation, primarily in the dorsocaudal lung region.
- In the most severely affected sections, there was evidence of veno-occlusive remodeling. This remodeling was associated with hemosiderosis, fibrosis, enlargement of vessels within the pleura and interlobular septa, and bronchial neovascularization.
- The findings propose that the regional veno-occlusive remodeling, particularly within the caudodorsal lung fields, contributes to the development of EIPH. It suggests that the venous remodeling leads to regional vascular congestion and hemorrhage, hemosiderin accumulation, fibrosis, and bronchial angiogenesis.
Conclusion
- This research has helped identify a potentially significant factor in the pathogenesis of EIPH in Thoroughbred horses. Understanding this veno-occlusive remodeling process could provide valuable insights into the prevention and treatment of EIPH and help enhance the athletes’ wellness and performance.
Cite This Article
APA
Williams KJ, Derksen FJ, de Feijter-Rupp H, Pannirselvam RR, Steel CM, Robinson NE.
(2008).
Regional pulmonary veno-occlusion: a newly identified lesion of equine exercise-induced pulmonary hemorrhage.
Vet Pathol, 45(3), 316-326.
https://doi.org/10.1354/vp.45-3-316 Publication
Researcher Affiliations
- Department of Pathobiology and Diagnostic Investigation, College of Veterinary Medicine, Michigan State University, East Lansing, MI 48824, USA. williamsk@dcpah.msu.edu
MeSH Terms
- Animals
- Collagen / metabolism
- Functional Laterality
- Horse Diseases / etiology
- Horse Diseases / pathology
- Horses
- Iron / metabolism
- Lung / pathology
- Physical Conditioning, Animal / adverse effects
- Pulmonary Veno-Occlusive Disease / etiology
- Pulmonary Veno-Occlusive Disease / pathology
- Pulmonary Veno-Occlusive Disease / veterinary
Citations
This article has been cited 7 times.- Rocchigiani G, Verin R, Uzal FA, Singer ER, Pregel P, Ressel L, Ricci E. Pulmonary bleeding in racehorses: A gross, histologic, and ultrastructural comparison of exercise-induced pulmonary hemorrhage and exercise-associated fatal pulmonary hemorrhage.. Vet Pathol 2022 Nov;59(6):973-982.
- Ceriotti S, Bullone M, Leclere M, Ferrucci F, Lavoie JP. Severe asthma is associated with a remodeling of the pulmonary arteries in horses.. PLoS One 2020;15(10):e0239561.
- Blott S, Cunningham H, Malkowski L, Brown A, Rauch C. A Mechanogenetic Model of Exercise-Induced Pulmonary Haemorrhage in the Thoroughbred Horse.. Genes (Basel) 2019 Nov 1;10(11).
- Bayly W, Lopez C, Sides R, Bergsma G, Bergsma J, Gold J, Sellon D. Effect of different protocols on the mitigation of exercise-induced pulmonary hemorrhage in horses when administered 24 hours before strenuous exercise.. J Vet Intern Med 2019 Sep;33(5):2319-2326.
- da Silva KM, Otaka JNP, Gonçalves CAP, Silva EGA, de Alencar NX, Lessa DAB. Association between exercise-induced pulmonary hemorrhage and inflammatory airway disease in polo ponies.. J Equine Sci 2017;28(2):55-59.
- Kim DS, Lee M, Kwon OJ, Jeong I, Son JW, Na MJ, Kwon SJ. A 45-Year-Old Man With Recurrent Dyspnea and Hemoptysis during Exercise: Exercise-Induced Pulmonary Hemorrhage/Edema.. Tuberc Respir Dis (Seoul) 2015 Oct;78(4):375-9.
- Hinchcliff KW, Couetil LL, Knight PK, Morley PS, Robinson NE, Sweeney CR, van Erck E. Exercise induced pulmonary hemorrhage in horses: American College of Veterinary Internal Medicine consensus statement.. J Vet Intern Med 2015 May-Jun;29(3):743-58.
Use Nutrition Calculator
Check if your horse's diet meets their nutrition requirements with our easy-to-use tool Check your horse's diet with our easy-to-use tool
Talk to a Nutritionist
Discuss your horse's feeding plan with our experts over a free phone consultation Discuss your horse's diet over a phone consultation
Submit Diet Evaluation
Get a customized feeding plan for your horse formulated by our equine nutritionists Get a custom feeding plan formulated by our nutritionists
