Omneity® Pellets
All-In-One Vitamin & Mineral Pellet
Mycobacterium avium subsp. hominissuis infection in horses with granulomatous enterocolitis – first report in Poland.
Abstract: Gastrointestinal mycobacteriosis in horses is difficult to diagnose because of the pathogen's intracellular nature and the non-specific clinical symptoms. Effective accurate diagnosis facilitates prognosis and treatment. Current diagnostic procedures and methods of collecting material do not permit definitive antemortem diagnosis. However, culturing, acid-fast bacilli staining, histopathology, PCR and immunological marker evaluation may prove useful. Unassigned: Three horses were admitted to a clinic for intensive care and a final diagnosis. Physical examination and additional tests were performed. Unfavourable prognoses and lack of treatment response prompted euthanasia decisions. Necropsy was performed, as were histological, microbiological and molecular investigations. Unassigned: The clinical condition of the animals deteriorated despite therapy. Two horses were euthanised when they did not respond to treatment and had poor prognoses. Intestinal mycobacteriosis caused by subsp. was diagnosed postmortem using laboratory investigations. One horse's diagnosis was established antemortem by cytological and microbiological examination of biopsy material from an abdominocentesis, and this animal was also euthanised because of its poor prognosis. Unassigned: Mycobacteriosis should be considered in the differential diagnosis of chronic debilitating equine diarrhoea in addition to rhodococcosis, lawsoniosis, salmonellosis, gastric ulcers and food intolerance. Peritoneal fluid obtained by abdominocentesis proved to be an effective diagnostic method for microbiological and molecular identification of subsp. in horses with suspected enteric mycobacteriosis and concomitant ascites.
© 2025 Beata Nowicka et al.
Publication Date: 2025-12-10 PubMed ID: 41497459PubMed Central: PMC12767164DOI: 10.2478/jvetres-2025-0067Google 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.
Overview
- This study reports the first confirmed cases of Mycobacterium avium subsp. hominissuis infection causing granulomatous enterocolitis in horses in Poland.
- The research highlights challenges in diagnosing equine gastrointestinal mycobacteriosis and proposes effective diagnostic approaches including abdominocentesis for ante-mortem detection.
Background and Importance
- Gastrointestinal mycobacteriosis is a challenging disease to diagnose in horses due to the intracellular nature of the pathogen and vague clinical symptoms.
- The disease presents as chronic, debilitating diarrhea and granulomatous inflammation of the intestines, with other differential diagnoses such as rhodococcosis, lawsoniosis, salmonellosis, gastric ulcers, and food intolerance commonly considered.
- Mycobacterium avium subsp. hominissuis is a subspecies within the Mycobacterium avium complex, recognized in other species but newly reported in horses in this Polish study.
Clinical Presentation and Case Descriptions
- Three horses were admitted to a clinic for intensive care due to chronic gastrointestinal symptoms and deterioration despite treatment.
- All animals exhibited non-specific clinical signs, complicating initial diagnosis.
- Two horses were euthanized following worsening of symptoms and poor prognosis after ineffective therapy.
- One horse was diagnosed ante-mortem through cytological and microbiological analysis of biopsy samples from abdominal fluid collected via abdominocentesis but was also euthanized due to poor prognosis.
Diagnostic Methods and Challenges
- Traditional diagnostic methods such as culturing, acid-fast bacilli staining, histopathology, PCR, and immunological markers can aid diagnosis but often fail to provide definitive ante-mortem results due to the intracellular lifestyle of the bacteria.
- The study underscores the value of peritoneal fluid obtained from abdominocentesis as a sample source for cytological, microbiological, and molecular identification of the pathogen in live animals with suspected intestinal mycobacteriosis.
- This method proved effective in identifying Mycobacterium avium subsp. hominissuis in horses that presented with ascites and enteric signs, facilitating earlier detection compared to traditional approaches.
Postmortem Findings and Confirmation
- Necropsy of the euthanized horses revealed granulomatous lesions in the intestines confirming the diagnosis of mycobacteriosis.
- Laboratory investigations including histological examination, microbiological culture, and molecular assays validated the presence of Mycobacterium avium subsp. hominissuis as the causative agent.
Implications and Recommendations
- The study recommends including Mycobacterium avium subsp. hominissuis infection in differential diagnoses of chronic diarrheal diseases in horses to ensure accurate diagnosis and appropriate management.
- Given the severity and poor prognosis associated with this infection, early detection through innovative sampling methods like abdominocentesis is critical.
- The research provides an important reference as the first documented case series of this infection in Polish horses, contributing to global veterinary knowledge on equine mycobacteriosis.
Cite This Article
APA
Nowicka B, Łopuszyński W, Krajewska-Wędzina M, Biazik A, Sobuś M, Polkowska I, Szacawa E.
(2025).
Mycobacterium avium subsp. hominissuis infection in horses with granulomatous enterocolitis – first report in Poland.
J Vet Res, 69(4), 545-552.
https://doi.org/10.2478/jvetres-2025-0067 Publication
Researcher Affiliations
- Department of Animal Surgery, 20-950 Lublin, Poland.
- Department of Pathomorphology and Forensic Veterinary Medicine, 20-950 Lublin, Poland.
- Department of Food Hygiene of Animal Origin, University of Life Sciences in Lublin, 20-950 Lublin, Poland.
- Department of Veterinary Surgery, Nicolaus Copernicus University in Toruń, 87-100 Toruń, Poland.
- Department of Diagnostics and Clinical Sciences, Institute of Veterinary Medicine, Nicolaus Copernicus University in Toruń, 87-100 Toruń, Poland.
- Department of Animal Surgery, 20-950 Lublin, Poland.
- Department of Bacteriology and Bacterial Animal Diseases, National Veterinary Research Institute, 24-100 Puławy, Poland.
Conflict of Interest Statement
Conflict of Interests Statement: The authors declare that there is no conflict of interests regarding the publication of this article.
References
This article includes 36 references
- Abukhalid N, Islam S, Ndzeidze R, Bermudez LE. Mycobacterium avium subsp. hominissuis interactions with macrophage killing mechanisms. Pathogens 2021;10:1365.
- Ayele WY, Bartos M, Svastova P, Pavlik I. Distribution of Mycobacterium avium subsp. paratuberculosis in organs of naturally infected bull-calves and breeding bulls. Vet Microbiol 2004;103:209.
- Buergelt CD, Green SL, Mayhew IG, Wilson JH, Merritt AM. Avian mycobacteriosis in three horses. Cornell Vet 1988;78:365.
- Charlesworth V. Multisystemic bovine mycobacteriosis in a pony with neurological signs and weight loss. Equine Vet Educ 2018;30:192.
- Cline JM, Schlafer DW, Callihan DR, Vanderwall D, Drazek FJ. Abortion and granulomatous colitis due to Mycobacterium avium complex infection in a horse. Vet Pathol 1991;28:89.
- Didkowska A, Majchrzak M, Załuski M, Brzezińska S, Jańczak D, Nowak M, Tchórz W, Augustynowicz-Kopeć E, Matusik K, Parniewski P. First report of Mycobacterium avium subsp. hominissuis in a black howler monkey (Alouatta caraya): a study with mycobacterial interspersed repetitive unit–variable number of tandem repeats genetic profiling. J Vet Res 2025;69:191.
- Fichtelová V, Králová A, Babák V, Kovařčík K. Effective control of Johne’s disease in large Czech dairy herds. J Vet Res 2022;66:61.
- Gonda MG, Chang YM, Shook GE, Collins MT, Kirkpatrick BW. Effect of Mycobacterium paratuberculosis infection on production, reproduction, and health traits in US Holsteins. Prev Vet Med 2002;80:103.
- Gunnes G, Nord K, Vatn S, Saxegaard F. A case of generalized avian tuberculosis in a horse. Vet Rec 1995;136:565.
- Kaczmarkowska A, Didkowska A, Kwiecień E, Stefańska I, Rzewuska M, Anusz K. The Mycobacterium avium complex – an underestimated threat to humans and animals. Ann Agric Environ Med 2022;29:22.
- Kalck KA. Inflammatory bowel disease in horses. Vet Clin North Am Equine Pract 2009;25:303.
- Khol JL, Kralik P, Slana I, Beran V, Aurich C, Baumgartner W. Consecutive excretion of Mycobacterium avium subspecies paratuberculosis in semen of a breeding bull compared to the distribution in feces, tissue and blood by IS900 and F57 quantitative real-time PCR and culture examinations. J Vet Med Sci 2010;72:1283.
- Konyha LD, Kreier JP. The significance of tuberculin tests in the horse. Am Rev Respir Dis 1971;103:91.
- Kriz P, Jahn P, Bezdekova B, Blahutkova M, Mrlik V, Slana I, Pavlik I. Mycobacterium avium subsp. hominissuis infection in horses. Emerg Infect Dis 2010;16:1328.
- Li L, Maboni G, Lack A, Gomez DE. Nontuberculous mycobacteria in horses: a narrative review. Vet Sci 2023;10:442.
- Lofstedt J, Jakowski RM. Diagnosis of avian tuberculosis in a horse by use of liver biopsy. J Am Vet Med Assoc 1989;194:260.
- Mair TS, Taylor FGR, Gibbs C, Lucke VM. Generalised avian tuberculosis in a horse. Equine Vet J 1986;18:226.
- Mattoo R. Targeting emerging Mycobacterium avium infections: perspectives into pathways and antimicrobials for future interventions. Future Microbiol 2021;16:753.
- Monki JAK, Hewetson M, Hahn S, Vainio K, Skrzypczak P. Disseminated alimentary mycobacteriosis in the horse: a retrospective study of nine cases. Equine Vet Educ 2016;28:614.
- Oaks JL. Mycobacterial infections. Equine Infectious Diseases 2007;Chapter 33, pp. 296–300.
- Pakarinen J, Nieminen T, Tirkkonen T, Tsitko I, Ali-Vehmas T, Neubauer P, Salkinoja-Salonen M. Proliferation of mycobacteria in a piggery environment revealed by mycobacterium-specific real-time quantitative PCR and 16S rRNA sandwich hybridization. Vet Microbiol 2007;120:105.
- Pearson EG, Heidel JR. Colonic and rectal biopsy as a diagnostic aid in horses. Compend Contin Educ Pract Vet 1998;20:1354.
- Perillo L, Cascone G, Antoci F, Piccione G, Giannetto C, Salonia R, Salina F, Giudice E, Monteverde V, Licitra F. Prevalence of infectious diseases on dairy farms classified on the basis of their biosecurity score. J Vet Res 2022;66:103.
- Radulski Ł, Krajewska-Wędzina M, Lipiec M. Prevalence of Mycobacterium tuberculosis complex infections in animals Part II. Companion animals (in Polish). Życie Weter 2022;97:604.
- Rónai Z, Csivincsik Á, Dán Á, Gyuranecz M. Molecular analysis and MIRU-VNTR typing of Mycobacterium avium subsp. avium, ‘hominissuis’ and silvaticum strains of veterinary origin. Infect Genet Evol 2016;40:192.
- Ryhner T, Wittenbrink M, Nitzl D, Zeller S, Gygax D, Wehrli Eser M. Infection with Mycobacterium avium subspecies avium in a 10 year old Freiberger mare. Schweiz Arch Tierheilkd 2009;151:443.
- Samba-Louaka A, Delafont V, Rodier MH, Cateau E, Héchard Y. Free-living amoebae and squatters in the wild: Ecological and molecular features. FEMS Microbiol Rev 2019;43:415.
- Shivaprasad HL, Palmieri C. Pathology of mycobacteriosis in birds. Vet Clin North Am Exot Anim Pract 2012;15:41.
- Silva FS, Lorenzett MP, Bianchi MV, Bastos HBA, Larentis GR, Paul LG, Snel GGM, Oliveira-Filho JP, Mattos RC, Sonne L. Mycobacterium branderi infection in a horse with granulomatous mesenteric lymphadenitis. J Comp Pathol 2019;168:30.
- Sutton DGM, Michel AL. Mycobacterial infections in equids: Clinical characteristics and diagnostic techniques. Equine Vet Educ 2018;30:197.
- Thiriot JD, Martinez-Martinez YB, Endsley JJ, Torres AG. Hacking the host: Exploitation of macrophage polarization by intracellular bacterial pathogens. Pathog Dis 2020;78:ftaa009.
- Thomas V, McDonnell G. Relationship between mycobacteria and amoebae: Ecological and epidemiological concerns. Lett Appl Microbiol 2007;45:349.
- Uzal FA, Arroyo LG, Navarro MA, Gomez DE, Asín J, Henderson E. Bacterial and viral enterocolitis in horses: a review. J Vet Diagn Invest 2021;34:354.
- Uzunkoy A, Harma M, Harma M. Diagnosis of abdominal tuberculosis: experience from 11 cases and review of the literature. World J Gastroenterol 2004;15:3647.
- Velázquez-Morales JV, Santillán-Flores MA, Gallegos-Sánchez J, Cuca-García JM, Navarro-Maldonado MDC, Rojas-Martínez RI, Cortez-Romero C. Detection of Mycobacterium avium subsp. paratuberculosis in reproductive tissue and semen of naturally infected rams. Anim Reprod 2019;18:930.
- . Global tuberculosis report 2023. World Health Organization 2023.
Citations
This article has been cited 0 times.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
