Testicular biopsy in psittacine birds (Psittaciformes): comparative evaluation of testicular reproductive status by endoscopic, histologic, and cytologic examination.

Knowledge of the reproductive cycle of male parrots is important for examining the male genital tract and for successful breeding, especially of endangered species. To evaluate different diagnostic methods and criteria concerning the classification of reproductive stages, we examined 20 testicular samples obtained at necropsy in psittacine birds of different species and testicular biopsy samples collected from 9 cockatiels (Nymphicus hollandicus) and 7 rose-ringed parakeets (Psittacula krameri) by endoscopy 4 times over a 12-month period. The testicular reproductive status was assessed histologically and then compared with the macroscopic appearance of the testicles and cytologic results. The histologic examination was nondiagnostic in 19 of 59 testicular biopsy samples. By contrast, the cytologic preparations were diagnostic in 57 of 59 biopsy samples. The results of the cytologic examination coincided with the histologic results in 34 of 38 biopsy samples and 18 of 20 necropsy samples. Macroscopic parameters displayed some differences between reproductive stages but provided an unreliable indication of the reproductive status. These results suggest that microscopic examination of a testicular biopsy sample is a reliable method for evaluating the reproductive status of male parrots and is preferable to the macroscopic evaluation of the testicle. Cytologic examination provides fast preliminary results, even when the histologic preparation is not sufficient for evaluation, but results may be erroneous. Thus, a combination of histologic and cytologic examination is recommended for evaluating testicular reproductive status.

Testicular biopsy in psittacine birds (Psittaciformes): impact of endoscopy and biopsy on health, testicular morphology, and sperm parameters.

Histologic examination of a testicular biopsy sample may be required to evaluate the reproductive status of male psittacine birds. The purpose of this study was to evaluate the viability of testicular sampling from live birds by assessing the impact on the birds' health, testicular integrity, and sperm quality. Testicular biopsy samples were obtained by endoscopy 4 times during 12 months from 9 cockatiels (Nymphicus hollandicus) and 7 rose-ringed parakeets (Psittacula krameri). Only 2 of 16 birds showed testicular cicatrization or divided testicular tissue after a single endoscopy. Further complications, such as damage to the air sacs or bleeding, predominantly occurred in subsequent endoscopies. In both species, endoscopy and testicular biopsy caused only minor or transient effects on sperm production and sperm quality. These results support that a single testicular biopsy is a viable method for evaluating the reproductive status of male psittacine birds.

Evaluating the reproductive status of the male budgerigar (Melopsittacus undulatus).

Limited knowledge about male psittacine reproduction reduces the success of breeding programmes. Within the scope of fecundity assessment, classification of male sexual status is essential for effective conservation of the species. The aim of the present study was to investigate the testes of male budgerigars (Melopsittacus undulatus), as psittaciform model species to verify their reproductive status by morphological and immunocytochemical examination. Using light microscopy, gonadal samples were categorized resulting in three reproductive states (active, intermediate, non-active). Calculation of testes weights plus measurement of tubular and interstitial dimensions displayed significant (p ≤ 0.05) differences between all three reproductive stages. Lipids in the testicular tubules, analysed by Sudan black staining and fluorescence microscopy (DAPI(2) mode) were highly present in non-active status. Immunocytochemistry involved two different hydroxysteroid dehydrogenases (HSD), 3ß-HSD and 17ß-HSD-2, as markers for steroidogenesis, as well as steroid receptors for androgens (AR), oestrogen (ER) and progesterone (PR). Both HSDs and AR declined in non-active gonads compared to active and intermediate stages, with a positive signal in germ and somatic cells of testis and epididymis. ER and PR were detected in testicular and epididymal cells, similarly expressed in all three stages. The proliferation rate of germ cells in the testicular tubules, obtained by Ki67, differed significantly in active (38.67%), intermediate (32.40%) and non-active (6.01%) status. According to this morphological study, we have been able to establish markers for the reproductive staging of psittacine testes. This knowledge will be useful to deepen reproductive biology in budgerigars.

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.

[The importance of nutrition counselling in veterinary practice]. / Die Rolle der Ernährung in der Kleintierpraxis.

OBJECTIVE: Collection of epidemiological data about the importance of nutrition counselling and current nutritional knowledge of veterinary surgeons. MATERIAL AND METHODS: A total of 707 veterinarians were interviewed based on a standardized questionnaire. The survey was divided into three sections and comprised the topics person and working environment, level of education and current knowledge regarding nutrition, as well as the significance of nutrition in daily practice. RESULTS: The majority of respondents (91.3%) worked in a practice with up to four veterinarians, where most of the participants (89.3%) treated up to 50 patients daily. On a scale from 1 to 5, the veterinarians evaluated their knowledge with a mean of 2.59 (± 0.798) and the importance of nutrition with a mean of 2.02 (± 0.818). Nutrition consulting was provided for at least half of the patients by 37.3% of the participants. The counselling was performed in different ways. The main reasons for a lack of consultancy despite a current indication were time and labor (37.1%) as well as the low willingness of customers to pay (34.6%). The majority of veterinarians were interested in further training concerning nutrition counselling. CONCLUSION: Nutrition consulting is an important part of daily veterinary practice but there is a demand for further training. CLINICAL RELEVANCE: Although the importance of nutrition is clear, only some of the veterinary surgeons perform consulting on a regular basis. In particular, in case of an existing indication, a nutrition consulting is advisable to ensure maximum success of treatment.

Antibody selection for immunocytochemical characterization of the male reproductive system in Psittaciformes.

The success of breeding programs is limited by the sparse knowledge about endocrine regulation and biochemical reactions in the psittacine male tract. The immunocytochemical analysis of parrots' testicular tissues provides an insight into their reproductive system but is often hampered by the lack of reliable antibodies. In the present study, we tested a large panel of antibodies raised against steroid receptors, steroidogenic enzymes, relaxin peptides including their receptors, and proliferation markers on paraffin sections of testicular tissue from eight psittacine genera representing three continents. All investigated species displayed the tested markers in somatic and germ cells of testis and epididymis, even though cell distribution was partly heterogenous and in species-specific patterns. The 17ß-hydroxysteroid-dehydrogenase-2, 3ß-hydroxysteroid-dehydrogenase, and smooth muscle actin allowed the cross-species differentiation between active and nonactive gonads. The remaining steroidogenic enzymes, steroid receptors, relaxin peptides, and Ki67 proved to be suitable to define reproductive activity depending on the parrot species. Adapting immunocytochemical methods to different psittacines was successful, though various cellular expression patterns do not allow the transfer of results among different parrot species. However, the availability of a reliable repertory of sexual markers is important to examine reproductive biology of psittacine birds.