American Society of Hirudotherapy

Validation of Medicinal Leeches (

Research article published in Frontiers in veterinary science (2022)

Last Updated: June 18, 2026Reviewed by: ASH Editorial Board
Research article — evidence reviewArticle reference
Evidence: Research reportGenomics & ProteomicsSafety & Infection ControlClinical TrialsKvapil P et al. · Frontiers in veterinary science, 2022

Abstract

Blood sampling is a challenging procedure in many captive animals. Although manual restraint or anesthesia are usually possible, they entail intense stress and a high risk of injuries or organ failure. Blood sampling using medicinal leeches (Hirudo medicinalis) represents a promising non-invasive alternative to venipuncture; however, leech blood meal was to date used only for qualitative analyses such as genetic or serological screenings. Hence, the aim of this study was to evaluate the suitability of the leech blood sampling method for quantification of hematological and biochemical parameters. Medicinal leeches were manually applied on 67 zoo animals of eleven species, and control blood samples were obtained by venipuncture of the jugular vein. The leeches drew up to 20 ml of blood in 20 to 55 min. Although most hematological and biochemical parameters were significantly altered in leech-derived samples, their values showed strong (r = 0.62-0.79; 10/24 parameters) to very strong (r > 0.8; 13/24 parameters) correlations with venipuncture in all blood parameters, except for sodium (r = 0.39). As the parameter alterations and correlations were similar among species, simple cross-species regression formulas were sufficient to correct the alterations, thereby ensuring good repeatability between leeches and venipuncture in most parameters. Our data thus suggest that medicinal leeches can be used as a reliable non-invasive and stress-reducing alternative to standard venipuncture, even for quantitative assays. This opens new opportunities for a significant improvement to animal welfare in zoological gardens, conservation programmes, and ecophysiological research, where quantification of blood parameters is often needed.

Abstract sourced from PubMed (NCBI) for the cited record. See the original publication for the authoritative version.

Publication typeJournal Article

Summary

Blood sampling is a challenging procedure in many captive animals. Although manual restraint or anesthesia are usually possible, they entail intense stress and a high risk of injuries or organ failure.

Why This Matters for Hirudotherapy

This study examined whether blood obtained by medicinal leeches (Hirudo medicinalis) manually applied to 67 zoo animals across eleven species could yield reliable quantitative hematological and biochemical measurements compared to standard venipuncture controls. The leeches drew up to 20 mL of blood per feeding, and after cross-species regression correction, leech-derived samples correlated strongly with venipuncture values for most parameters. For ASH's domain, the study provides practical data on H. medicinalis feeding performance and reliability in a controlled application context. However, the work concerns diagnostic blood sampling methodology in veterinary settings—not therapeutic hirudotherapy, leech salivary biochemistry, or clinical outcomes—and its relevance to ASH's core focus is indirect.

Citation

Validation of Medicinal Leeches (

Kvapil P et al. · Frontiers in veterinary science, 2022

Added to ASH library: March 18, 2026 · Site last updated: June 18, 2026

This website provides educational information and does not constitute medical advice, diagnosis, or treatment recommendations. Medicinal leech therapy carries clinically meaningful risks and should be performed only by qualified clinicians under institutionally approved protocols. FDA 510(k) clearance for medicinal leeches is limited to specific indications; investigational and off-label discussions are labeled accordingly. For patient-specific guidance, consult a qualified healthcare provider.