Colheita farmacológica de sêmen de onças-pardas (Puma concolor: Mammalia: Carnivora: Felidae)

Pharmacological semen collection in domestic and wild canids and felids: literature review

Semen collection methods vary greatly and rely on the practitioner's expertise, available materials, and the specific behavioral traits of the male animals involved. When it comes to domestic cats, wild felids, and canids, semen collection is particularly challenging. Thus, given the difficulty of semen collection in these species, pharmacological semen collection (PSC) stands out since it is a quick and straightforward method that does not require specific equipment. The PSC consists of administering α2-adrenergic receptor agonist drugs, mainly medetomidine, and dexmedetomidine, aiming semen release into the urethra with posterior urethral catheterization and sperm recovery. This technique was primarily described in domestic cats and wild felids, and despite the decreased seminal volume, the retrieved semen is highly concentrated and presents good quality. However, further studies are required to optimize semen collection in domestic dogs and wild canids. Therefore, the purpose of this review is to provide a comprehensive overview of the research developed on pharmacological semen collection (PSC) in the past few decades. The objective is to equip professionals with the essential knowledge required for the efficient application of this technique in both domestic and wild canids and felids and to make a valuable contribution to conservation efforts and the preservation of biodiversity, aligning with the principles of One Conservation.

Cryopreservation of jaguar (Panthera onca) sperm cells using different cryoprotectants and different thawing temperatures

The cryopreservation of jaguar semen must be improved to produce high-quality biobanking doses. Until now, the rare studies of semen freezing in the species have only evaluated glycerol, always with a significant reduction in sperm quality in thawed semen. The purpose of this study was to assess the efficacy of three cryoprotectants, dimethylsulfoxide (DMSO), glycerol (GLY), and methanol (MET), in the cryopreservation of jaguar semen in an LDL-based extender, as well as the effect of thawing temperature on dosage quality. Five mature males with a history of reproduction were used. On the males, an infrared thermal image (IRT) was captured, the spicules and testes were analyzed, and the CASA system was used to evaluate the quality of fresh and thawed sperm. The superficial IRT was 4.6 ± 1.2 °C cooler than the anal sphincter, and the semen measured between 27.3 and 28.7 °C shortly after exiting the urethra. The total motility of fresh sperm was 55.3 ± 22.6%, and progressive motility was 36.3 ± 18%. The total motility of thawed sperm was 5.28 ± 2.51%, 4.49 ± %2.49, and 0.51 ± 0.62% for DMSO, GLY, and MET, respectively. DMSO and GLY performed better than MET, and there was no difference in thawing temperature (37°C 30 s vs. 50°C 12 s). All animals exhibit a considerable level of morphological changes in sperm. Low amounts of total and progressive motility were found in the thawed sperm. Males with a high level of sperm morphological changes were found to be fertile, but the lone male with normospermia was infertile. Thus, we contest the applicability of the commonly used morphological classification for bovines to felid species.

Morphological, Ultrastructural, and Immunocytochemical Characterization and Assessment of Puma (Puma concolor Linnaeus, 1771) Cell Lines After Extended Culture and Cryopreservation

Cell lines are valuable tools to safeguard genetic material from species threatened with extinction that is mainly due to human action. In this scenario, the puma constitutes a species whose population is being rapidly reduced in the ecosystems it inhabits. For the first time, we characterized puma skin-derived cell lines and assessed these cells after extended culture (experiment 1) and cryopreservation (experiment 2). Initially, we identified and characterized four dermal fibroblast lines using morphology, ultrastructure, and immunofluorescence assays. Moreover, we evaluated the effects of culture time (1st, 3rd, and 10th passages) and cryopreservation on their morphology, ultrastructure, viability, metabolism, proliferative activity, reactive oxygen species (ROS) levels, mitochondrial membrane potential (ΔΨm), and apoptosis. The cells showed a typical spindle-shaped morphology with centrally located oval nuclei. The cells were identified as fibroblasts by staining for vimentin. In vitro culture after the 1st, 3rd, and 10th passages did not alter most of the evaluated parameters. Cells in the 3rd and 10th passages showed a reduction in ROS levels (p < 0.05). The ultrastructure revealed morphological damage in the prolongments, and nuclei of cells derived from the 3rd and 10th passages. Moreover, cryopreservation resulted in a reduction in ΔΨm compared with that of noncryopreserved cells, suggesting that the optimization of cryopreservation methods for puma fibroblasts is essential. In conclusion, we found that viable fibroblasts could be obtained from puma skin, with slight changes after the 10th passage in in vitro culture and cryopreservation. This is the first report on the development of cell lines derived from pumas.

Assessment of thawed sperm quality from feline species: Ocelot (Leopardus pardalis) and oncilla (Leopardus gutullus)

This study aimed to evaluate the cryopreservation effects on the semen of oncilla (Leopardus guttulus, n = 5, 15 ejaculates) and ocelot (Leopardus pardalis, n = 5, 17 ejaculates) and compare two extenders (commercial and non-commercial extender). An andrological exam was conducted (testicle measurements and penis evaluation), including semen collection by electroejaculation. After collection, the semen was assessed to volume, color, pH, sperm motility, vigor, sperm number in the ejaculate, viability, membrane integrity, and sperm morphology. Samples were centrifuged (300 g for 10 min) and pellet diluted in two extenders (TRIS/glucose/egg yolk and BotuCRIO®), packed into 0.25 mL French straws (20 × 10⁶ spermatozoa/mL), equilibrated at 5 °C for 1 h (<0.5 °C/min), freezing in nitrogen vapor for 20 min. Thawing was achieved at 46 °C for 15 min. Thawed samples were evaluated to the same characteristics and ultrastructural analysis. There is no difference for extenders, but in ocelot the spermatozoa maintained higher quality after thawing. Major defects were increased in thawed samples, especially acrosome injuries, in both species. Semen contamination by urine was remarkable to oncilla (53% of the ejaculates) which can have reduced sperm cryoresistance of this species. Ultrastructural analysis endorsed morphological analysis under light microscopy and identified cells with acrosome vesiculation. In conclusion, the spermatozoa of ocelot were more cryoresistent and the extender commercial and non-commercial were suitable for their cryopreservation. Other extenders should be investigated for oncilla.

Can detomidine replace medetomidine for pharmacological semen collection in domestic cats?

Among the different methods used for semen collection from domestic cats, the pharmacological collection by urethral catheterization becomes disruptive. Medetomidine is the elected α²-adrenoceptor agonist for that, but in several countries, it is not commercially available. This study aimed to evaluate the efficacy of detomidine compared to medetomidine in collecting semen by urethral catheterization in domestic cats. Urethral catheterization was performed on 13 mongrel cats using a disposable semi-rigid tomcat urinary catheter. Of the 19 semen collections performed with medetomidine induction, 94.7% were successful, while with detomidine induction, only 56.3% of 16 were successful. The values semen samples variables were as follows for volume - 10.56 ± 0.4 vs 8.88 ± 0.5 mL, motility - 171.67 ± 0.79 vs 49.77 ± 3.45%, vigor - 4.1 ± 0.03 vs 3.10 ± 0.1 and concentration - 3.24 ± 0.19 vs 2.15 ± 0.13 ×10⁹ sperm/mL respectively for medetomidine and detomidine group. The failure in semen collections with detomidine was mainly due to azoospermic samples, poor urethral relaxation, insufficient volume, or contamination of urine. The sperm concentration was also lower in the detomidine group (P <0.05) when compared to medetomidine. However, when the volume of semen collected was compared, we found no statistical differences. Despite its low performance in collecting semen from cats, detomidine may be an alternative when medetomidine is not accessible.

Spermatic profile of captive giant anteaters (Myrmecophaga tridactyla): Knowing more to preserve better

The giant anteater (Myrmecophaga tridactyla) is being threatened by natural habitat destruction and fragmentation, illegal hunting and road kills. In this context, the generation of basic information on the reproductive parameters of this species is vital, aiming to improve reproductive management via, amongst others, assisted reproductive technologies. This study aimed to describe the morphological and functional features of semen collected from captive giant anteaters. Electroejaculation was performed in 13 animals housed in zoos located in São Paulo state, Brazil. Semen samples were collected from 13 animals in 16 procedures. Samples were evaluated for volume, motility, vigor, pH, concentration, sperm morphology, and functional tests. The following mean values were obtained: volume 1.28 ± 0.27 mL; motility 28.3 ± 6.2%; vigor 2.4 ± 0.25; concentration 129.4 ± 36.1 × 10⁶ sperm/mL; pH 7.4 ± 0.2. Total acrosome, head, midpiece, and tail sperm abnormalities were 3.2 ± 0.8%, 25.4 ± 3.6%, 20.7 ± 3.2%, and 14.7 ± 2.6%, respectively. Intact acrosome was found in 83.7 ± 3.1% and intact membrane in 81.1 ± 4.0% of all samples collected. Mitochondrial activity was 66.4 ± 6.0% (Class I), 18.7 ± 2.9% (Class II), 8.0 ± 2.0% (Class III), 3.9 ± 1.0% (Class IV), and 3.0 ± 0.9% (Class V). Sperm DNA fragmentation rate was 13.2 ± 3.7%. These results indicated that electroejaculation is a feasible method for semen collection in giant anteaters, allowing a more detailed description of the semen in this species.

Medetomidine may cause heart murmur in Cougars and Jaguars: case report

We report heart murmur in Jaguars and Cougars found during reproductive procedures for semen and oocyte collection.  Two male Cougars (n=2) and three female Jaguars (n=3) were examined.  Anesthesia was performed with ketamine and medetomidine in males.  Females also received propofol and were maintained with isoflurane.  The animals were evaluated during anesthetic monitoring with multiparameter monitor alongside clinical examination, ambulatory electrocardiogram and echocardiogram.  All animals presented mitral valve regurgitation under anesthesia, but without morphological changes in the cardiac structure or hemodynamic changes.  Medetomidine may cause transitory heart murmur in healthy Jaguars and Cougars.   

Sperm evaluation and morphological description of male genitalia of meerkats (Suricata suricatta)

In ex situ conditions, little is known about the reproductive biology of meerkats. The aim of present study was to describe the morphological aspects of male genital organs and accessory glands using macroscopic evaluation, ultrasonography, and radiography, as well as describing semen characteristics post-electroejaculation. The results indicated anatomical characteristics of meerkats are very similar to those of cats, having a prostate, accessory bulbourethral glands, and an elongated and radiopaque structure in the penis, which is indicative of there being a baculum. The testicular volume was 0.81 cm³ (± 0.10) and the relative testis weight was 1.37 cm³/kg (± 0.15). Both testicles are present in the scrotum, which has an ellipsoidal shape, homogeneous texture, hypoechoic parenchyma and are encased in a hyperechoic tunica albuginea. Electroejaculation was effectively induced in all animals for semen collection with utilization of medetomidine and ketamine. The values semen samples variables were as follows for volume - 0.125 ± 0.193 mL, motility - 19.8 ± 18.6 %, vigor - 1.9 ± 1.0, concentration - 40.5 ± 25.2 × 10⁶ sperm/mL and morphologically normal sperm - 10.8 ± 6.6 %. This is the first study in which there is a description of morphological and imaging aspects of the male reproductive tracts of meerkats, as well as the seminal characteristics after using electroejaculation for semen collection. Knowledge of anatomical and seminal characteristics is essential for implementation of assisted reproduction programs, as well as reproductive management in the species.