Comparative examination of testicular biopsy samples and influence on semen characteristics in budgerigars (Melopsittacus undulatus).

Although breeding of companion birds has become increasingly popular over the last decades, evaluating avian fecundity is rarely addressed and remains a challenge. Whereas histologic examination of a testicular biopsy sample is useful in evaluating reproductive status, as well as in identifying pathologic changes, cytologic examination is a much quicker method and is less invasive. To determine if cytologic examination of testicular impression smears is reliable compared with histologic examination in assessing reproductive status, we evaluated results in 16 live and in 14 dead male budgerigars (Melopsittacus undulatus). In most birds, macroscopic evaluation, combined with histologic or cytologic examination, resulted in a consistent grading of testicular reproductive stage. However, some testes assessed as inactive macroscopically showed advanced reproductive stage on histologic examination. Although a single biopsy caused no permanent damage to the testes and did not impact the general health status of the examined birds, repeated endoscopic examination resulted in testicular cicatrization or adhesions with the air sacs. In addition, some birds had delayed recovery after endoscopy. A biopsy of 1 testis done once or even repeatedly during a 1-year period had no impact on sperm production or quality.