Analgesic efficacy of ultrasound-guided transversus abdominis plane block in dogs undergoing ovariectomy.

Background: In medicine, the transversus abdominis plane (TAP) block has been shown as an effective method of analgesia in several surgical procedures. In this context, this prospective, randomized, blinded study aimed to evaluate the analgesic efficacy of TAP block, guided by ultrasound in female dogs submitted to ovariectomy. Methods: Therefore, 32 animals randomly assigned in two groups (n = 16) were used. Groups consisted of TAP block control (TBC) which received water injection (0.2 ml kg-1 point), and TAP block bupivacaine (TBB) which received bupivacaine (0.2 ml kg-1 point at 0.25%); both groups were submitted to four-point approach. Animals were pre-medicated with acepromazine (0.03 mg kg-1) and meperidine (2 mg kg-1) IM, propofol was used as anesthetic induction (3-5 mg kg-1) IV, and isoflurane was used to maintain. To standardize groups, the animals received a continuous infusion of remifentanil (0.2µg kg-1 min) and rocuronium (0.6 mg kg-1) IV in the intraoperative period. Variables measured were the heart and respiratory rates, blood pressure, temperature, peripheral oxyhemoglobin saturation, exhaled carbon dioxide concentration, exhaled isoflurane concentration, serum cortisol, analgesia, and sedation. Before the pre-anesthetic medication (Baseline) and 1, 2, 4, 6, and 8 h after extubation, pain and sedation were assessed using a numeric rating scale (NRS), Glasgow composite measure pain scale (GCMPS-SF), and sedation scale. Moreover, serum cortisol was measured at different moments. Results: The results show that in the intraoperative period, there was no significant difference between groups. After surgery, in TBC, 13 out of 16 animals required analgesic rescue, whereas, in TBB, this occurred only in one animal. Regarding the measurement of serum cortisol, the TBC group showed a significant difference when compared to the baseline time in the traction of the first ovary (p < 0.0001), 2 h (p = 0.0441), and 8 h (p = 0.0384) after extubation. In TBB, cortisol showed a significant increase only in the traction of the first ovary and 2 h after extubation (p < 0.0001). Conclusion: The technique using ultrasound-guided TAP block in two points approach by hemiabdomen with 0.2 ml kg-1 bupivacaine 0.25% was effective in providing post-operative analgesia in dogs undergoing ovariectomy.

Influence of cooling temperature in sperm subpopulations of domestic cats.

The objective of this study was to identify and compare domestic feline sperm subpopulations, chilled at -1 °C for 24 and 48 h, as well as to analyze the sperm frequency in different subpopulations. Ten adult cats were used. Sperm collection was performed using electroejaculation (EEJ). Spermatic kinetics were evaluated using a computerized system at three moments: fresh, 24 and 48 h after refrigeration. The ejaculates were divided into a group refrigerated at -1 °C (n = 5,) and a group refrigerated at 4 °C (n = 5),. A total of 1560 spermatozoa were analyzed individually, and the sperm subpopulations were identified using multivariate statistics. Three spermatic subpopulations were defined using prior analysis of the hierarchical dendrogram. A principal components analysis (PCA) identified the existence of three groups with higher iterations at the three moments: PC1 (VAP, VCL, VSL, ALH, SVI), PC2 (STR, LIN, WOB and SMI) and PC3 (BCF). Subpopulation 1, after 48 h of refrigeration at -1 °C, and subpopulation 3, after 24 h of refrigeration at 4 °C, maintained their sperm quality, which allowed us to characterize the groups of spermatozoa that were resistant to cryopreservation. The present study identified three well defined ejaculate spermatozoa subpopulations, with proportional distributions between the groups and two refrigeration resistant subpopulations.

Effects of chemical castration using 20% CaCl2 with 0.5% DMSO in tomcats: Evaluation of inflammatory reaction by infrared thermography and effectiveness of treatment.

This study used infrared thermography to monitor the immediate inflammatory reaction to an intratesticular injection of 20% (calcium chloride) CaCl2 with 0.5% dimethyl sulfoxide (DMSO) for chemical castration and to provide evidence of the treatment's clinical viability. Six animals received a 0.25 mL intratesticular injection of 20% CaCl2 with 0.5% DMSO in each testis. Thermographic imaging, testicular measurement, penile spine evaluation, electroejaculation, and sperm analysis were performed before the injection. Eighty days post-injection, the cats were evaluated again, then received an orchiectomy followed by histological analysis. Infrared thermography of the testicular area was performed before (M0) and after anesthesia (M0A); after electroejaculation (M0E); 10 min (M1), 1 h, (M2) and 6 h (M3) after the injection for seven consecutive days (M4-10); after 15 (M11) and 30 days (M12); and after 80 days, before and after anesthesia and after electroejaculation (M13, M13A and M13E). No cats had a significant increase in testicular temperature or behavioral changes. All animals were azoospermic and had a 50% reduction in total testicular volume after 80 days. Histologically, the testes showed different degrees of degeneration, necrosis, calcification and replaced connective tissue, as well as Leydig cell hyperplasia in 7/12 of the testes. Infrared thermography efficiently diagnosed and monitored scrotal inflammation caused by intratesticular injection of 20% CaCl2 solution with 0.5% DMSO, and it is suggested that a single injection of this compound can cause azoospermia after 80 days. We concluded by infrared thermography with a clinical exam, that the adverse reactions were minimal and did not interfere with animal welfare.