Clinical features, diagnostic findings, and treatment response in Finnish horses examined for equine inflammatory bowel disease.
Abstract: Equine inflammatory bowel disease (IBD) is challenging to diagnose and treat. Although the number of horses examined due to suspicion of IBD is increasing, the different treatments in clinical patients and their responses are not well documented. We sought to characterize the demography, signs, clinical and rectal biopsy findings, and treatment response in Finnish horses suspected to have IBD. Horses undergoing clinical examination due to suspected IBD in 2022 and with a good-quality rectal biopsy were selected for the study. General information, signs, clinical and histological findings, and treatment response were collected retrospectively from owners and participating clinics. The effect of variables on symptoms, treatment response, and biopsy results was assessed using statistical methods (significance level P < 0.05). Results: A total of 152 horses was included. The most common signs were poor performance (68%), nonspecific pain (43%), and irritation/aggression (41%). Intestinal signs were observed in 63% of horses. Sixty-six percent of horses had ultrasonographic changes in the small intestine, and 37% had gastric ulcers. Orthopaedic examination was mentioned in 12% of horses. In rectal biopsy, horses had eosinophilic (35%), lymphoplasmacytic (18%), or neutrophilic (6%) inflammation; 40% had no inflammation. Inflammation was observed mostly in horses aged 5-8 years (P = 0.015). Changes in rectal biopsy were associated with certain behaviour changes (P = 0.002). Sixty-eight percent of horses were treated with medication and dietary change. Glucocorticoids were first-line treatment in 73% of medicated horses. Medication was changed during treatment in 35 horses. Treatment response was considered good in 49% of horses. Access to pasture was associated with a reduction in signs (P = 0.001). Signs, clinical and biopsy findings, and treatment type were not associated with treatment response. Medication change was associated with poorer treatment response. Conclusions: Most horses had at least a partial positive treatment response. Investment in pasture-like management, forage, and exercise regimen may be helpful during out-of-pasture season. Performance issues and nonspecific behaviour changes should be included as possible IBD-related signs, but a more structured clinical diagnostic workup is needed for a reliable assessment of treatment response and to increase the diagnostic value of rectal biopsy.
© 2025. The Author(s).
Publication Date: 2025-12-03 PubMed ID: 41339891PubMed Central: PMC12781275DOI: 10.1186/s13028-025-00831-8Google Scholar: Lookup
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Summary
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Overview
- This study investigates the clinical signs, diagnostic findings, and treatment outcomes in Finnish horses suspected of having equine inflammatory bowel disease (IBD).
- The research analyzes data from 152 horses examined in 2022, focusing on symptoms, rectal biopsy results, and responses to different treatments.
Introduction to Equine Inflammatory Bowel Disease (IBD)
- Equine IBD is a complex condition affecting the intestines of horses and is difficult to diagnose and treat effectively.
- Increasing numbers of horses are suspected of having IBD, but clinical treatment approaches and their effectiveness remain poorly documented.
- The study aims to fill gaps in understanding by characterizing clinical signs, diagnostic findings particularly from rectal biopsies, and treatment responses.
Methods
- Horses selected were those undergoing clinical examination for suspected IBD during 2022 with good-quality rectal biopsy samples.
- Data collected retrospectively included:
- General demographic information (age, sex, etc.)
- Clinical signs observed by veterinarians and owners
- Histological findings from rectal biopsies
- Treatment types and outcomes
- Statistical analysis (significance at P < 0.05) was done to assess how variables affected symptoms, biopsy results, and treatment success.
Results: Clinical Features and Diagnostics
- A total of 152 horses were included in the study.
- Common clinical signs were:
- Poor performance (68%)
- Nonspecific pain (43%)
- Irritation/aggression (41%)
- Intestinal signs in 63% of horses
- Additional diagnostics showed:
- 66% had small intestine abnormalities on ultrasound
- 37% had gastric ulcers
- Only 12% had orthopedic examinations mentioned, suggesting musculoskeletal factors might be less studied
Results: Histological Findings from Rectal Biopsies
- Types of inflammation detected:
- Eosinophilic inflammation: 35%
- Lymphoplasmacytic inflammation: 18%
- Neutrophilic inflammation: 6%
- No inflammation: 40%
- Inflammation was significantly more common in horses aged 5-8 years.
- Behavior changes were statistically linked to biopsy findings, suggesting a relationship between certain inflammatory patterns and alteration in horse behavior.
Results: Treatment and Response
- 68% of horses received treatment combining medication and dietary changes.
- Glucocorticoids were the first-line treatment in 73% of those medicated.
- Medication adjustments occurred during treatment for 35 horses, indicating challenges in achieving optimal therapy.
- Overall, treatment response was considered good in 49% of horses.
- Access to pasture was significantly associated with reduction in clinical signs, emphasizing environmental management benefits.
- No direct association was found between:
- Signs or biopsy findings and treatment response
- Type of treatment and treatment response
- However, medication changes were linked to poorer treatment outcomes, possibly reflecting more severe or treatment-resistant cases.
Conclusions and Implications
- Most horses showed at least some positive response to treatment, highlighting the potential benefits of current management strategies.
- Encouraging pasture-like management, appropriate forage, and exercise can be beneficial, especially outside the grazing season.
- Clinical signs related to performance issues and nonspecific behavioral changes should be recognized as part of the IBD symptom spectrum.
- There is a need for:
- More structured and thorough clinical diagnostic protocols for equine IBD
- Improved methods to reliably assess treatment responses
- Better interpretation and diagnostic use of rectal biopsy findings
Cite This Article
APA
Pekkarinen HM, Simola U, Niinistö KE, Syrjä PES.
(2025).
Clinical features, diagnostic findings, and treatment response in Finnish horses examined for equine inflammatory bowel disease.
Acta Vet Scand, 68(1), 2.
https://doi.org/10.1186/s13028-025-00831-8 Publication
Researcher Affiliations
- Production and Companion Animal Pathology, Animal Health Diagnostic Unit, Finnish Food Authority, Mustialankatu 3, 00790, Helsinki, Finland. henna.pekkarinen@helsinki.fi.
- Section for Pathology and Parasitology, Faculty of Veterinary Medicine, University of Helsinki, P.O. Box 57, Helsinki, Finland. henna.pekkarinen@helsinki.fi.
- BC Platforms, Tykistökatu 4, 20520, Turku, Finland.
- Veterinary Teaching Hospital, Equine Hospital, Faculty of Veterinary Medicine,, University of Helsinki, P.O. Box 57, Helsinki, Finland.
- Section for Pathology and Parasitology, Faculty of Veterinary Medicine, University of Helsinki, P.O. Box 57, Helsinki, Finland.
MeSH Terms
- Animals
- Horses
- Horse Diseases / diagnosis
- Horse Diseases / pathology
- Horse Diseases / drug therapy
- Horse Diseases / therapy
- Inflammatory Bowel Diseases / veterinary
- Inflammatory Bowel Diseases / diagnosis
- Inflammatory Bowel Diseases / pathology
- Inflammatory Bowel Diseases / drug therapy
- Inflammatory Bowel Diseases / therapy
- Female
- Finland / epidemiology
- Male
- Retrospective Studies
- Biopsy / veterinary
- Treatment Outcome
Conflict of Interest Statement
Declarations. Ethics approval and consent to participate: The study was approved by the Research Ethics Committee on Animal Research of the University of Helsinki (18.05.2022). Informed consent to participate in the study was obtained from horse owners. Clients of the diagnostic service at FACIT and at the Section of pathology and parasitology, Faculty of Veterinary Medicine, University of Helsinki, were informed that the samples may be further used for research purposes upon submission of a diagnostic sample. KN and PS have a client relationship with the owners of the horses included, either as equine clinician (KN) or as veterinary pathologist (PS). All data were pseudonymized behind a diary number and stored at in secure database only accessible to the researchers. Consent for publication: Not applicable. Prior publication: Parts of the data included in this article have previously been presented in the 2024 Finnish Veterinary Congress, Helsinki, Finland, 13–15 November 2024. Competing interests: The authors declare that they have no competing interests.
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