Canine Sperm Concentration: Comparison Between Neubauer Cell Counting, Photometers and a CASA System

Area of Science:

• Veterinary Andrology
• Reproductive Biology
• Sperm Analysis Techniques

Background:

• Accurate canine sperm concentration assessment is crucial for reproductive success and artificial insemination.
• Existing methods for sperm counting, including counting chambers, spectrophotometry, and automated analyzers, vary in reliability.
• The influence of seminal diluents (translucent vs. opaque) on the accuracy of these methods is not well-established.

Purpose of the Study:

• To compare the accuracy of three methods for evaluating canine sperm concentration.
• To assess the impact of translucent and opaque media on the performance of these sperm evaluation techniques.
• To identify the most reliable method for canine sperm concentration analysis in different diluents.

Main Methods:

• Eight canine ejaculates were collected and divided into aliquots.
• Samples were diluted in either a translucent buffered solution or an opaque egg yolk-based medium.
• Sperm concentration was evaluated using a counting chamber (reference method), Accuread and SDM1 photometers, and a Hamilton Thorne IVOS II (HT-IVOS II) CASA analyzer.

Main Results:

• The HT-IVOS II analyzer with immobilized spermatozoa demonstrated good agreement with the counting chamber in translucent media.
• Accuread photometer showed reasonable differences but poor statistical agreement; SDM1 and HT-IVOS II (immobilized) had poor agreement in translucent media.
• None of the tested techniques (SDM1, Accuread, HT-IVOS II) agreed with the reference method in opaque media, and all were unreliable across both media types.

Conclusions:

• Current spectrophotometry and CASA methods show limitations in accurately assessing canine sperm concentration, especially in opaque media.
• The HT-IVOS II analyzer with immobilized sperm is the most reliable automated method in translucent media compared to spectrophotometers.
• Further research with larger sample sizes and inclusion of flow cytometry is recommended to improve sperm analysis accuracy.