Hematological and biochemical reference intervals for wild caught Eurasian otter from Spain

Area of Science:

• Wildlife toxicology
• Veterinary hematology
• Conservation medicine

Background:

• Reintroduction projects require baseline health data for target species.
• Establishing reference intervals for wild populations is crucial for health monitoring.
• Eurasian otters (Lutra lutra lutra) are a key species in European aquatic ecosystems.

Purpose of the Study:

• To determine hematologic and serum chemistry reference intervals for wild Eurasian otters.
• To provide data supporting health assessments during reintroduction programs.
• To compare hematologic values with North American river otters (Lutra canadensis).

Main Methods:

• Blood samples collected via jugular venipuncture from 33 wild Eurasian otters.
• Hematology and serum chemistry analyses performed on collected samples.
• Statistical analysis to determine means, standard deviations, and ranges for various analytes.

Main Results:

• Reference intervals established for 19 hematologic and 28 serum chemistry parameters.
• No significant sex-based differences observed in most analytes.
• Elevated leukocyte and neutrophil counts, decreased eosinophil and lymphocyte counts noted compared to previous studies.
• Higher aspartate aminotransferase and creatine kinase activities observed.
• Eurasian otters exhibited lower erythrocyte counts but higher mean corpuscular volume and mean corpuscular hemoglobin than river otters.

Conclusions:

• Established reference intervals provide essential health benchmarks for Eurasian otters.
• Hematologic differences noted may reflect environmental or physiological variations.
• Comparative data highlights interspecies differences between Eurasian and North American otters.
• Findings support effective health management in wild otter populations and conservation initiatives.