https://rd.uffs.edu.br/handle/prefix/4583 2026-05-31T14:45:10Z https://rd.uffs.edu.br/handle/prefix/9292 Título: Trazodona oral como adjuvante na anestesia intravenosa total em cães Autor(es): Arend, Nadine Primeiro Orientador: Freitas, Gabrielle Coelho Abstract/Resumen: Total intravenous anesthesia (TIVA) is widely used in veterinary medicine due to its ability to promote smoother recoveries and exert less impact on physiological parameters compared to inhalational anesthesia. Propofol is the primary agent used in this technique, although its dose-dependent adverse effects are a concern. To mitigate these effects, it is common to combine propofol with adjuvant drugs. Trazodone, an atypical antidepressant with anxiolytic properties, has gained attention in the management of canine stress-related conditions; however, its application as an anesthetic adjuvant remains underexplored. Few studies have investigated its interaction with anesthetic agents, particularly in the context of TIVA. This study evaluated the effects of trazodone as an adjuvant to propofol-based TIVA in dogs undergoing elective orchiectomy. Eighteen dogs were randomly assigned to two groups: placebo (GP) or trazodone (GT), receiving 12 mg/kg orally. Physiological parameters, sedation scores, laboratory tests, electrocardiography, recovery times, and adverse effects were assessed at various time points throughout the study. Following premedication with methadone (0.3 mg/kg), dogs underwent elective orchiectomy under TIVA with propofol. The induction dose of propofol was lower in the trazodone group (4.0 mg/kg) compared to the placebo group (5.5 mg/kg), while the infusion rate and recovery times were similar between groups. Trazodone was well tolerated, with minimal clinical adverse effects. Sedation scores increased in both groups, with slightly higher scores in the GT during the pre-anesthetic period, suggesting a possible progressive tranquilizing effect. Cardiovascular, respiratory, electrocardiographic, and laboratory parameters remained stable in both groups, with isolated changes showing no clinical relevance. In the GT, urinary findings were consistent with improved hemodynamics, without evidence of hepatic or renal toxicity. It is concluded that oral trazodone at 12 mg/kg is safe as an adjuvant in propofol-based TIVA, reducing the required induction dose and promoting greater clinical stability during the perioperative period, making it a promising option in anesthetic protocols for dogs. Instituição: Universidade Federal da Fronteira Sul Tipo: Dissertação 2025-07-16T00:00:00Z https://rd.uffs.edu.br/handle/prefix/9291 Título: Nisina como estratégia alternativa frente à resistência antimicrobiana: potencial terapêutico e abordagem in vitro entre mastite bovina e otite externa canina Autor(es): Ottobeli, Bruna Alves Primeiro Orientador: Benvegnú, Dalila Moter Abstract/Resumen: Antimicrobial resistance and biofilm formation stand out among the main factors associated with recurrence, chronicity, and therapeutic failure, highlighting the need for the development of alternatives with antimicrobial and antibiofilm potential capable of overcoming virulence and antimicrobial resistance. Given the limited availability of new pharmacological options, antimicrobial peptides such as nisin - a lantibiotic bacteriocin produced by Lactococcus lactis - have been investigated as therapeutic alternatives. Therefore, the present study aimed to evaluate the antimicrobial and antibiofilm activity, as well as the toxicity profile, of nisin against bacteria isolated from cases of canine otitis externa and bovine mastitis, in order to explore its potential in addressing AMR. In the first experiment, 34 bacterial isolates obtained from dogs diagnosed with otitis externa were evaluated, including Corynebacterium spp. and coagulase-negative Staphylococcus spp. Following microbiological identification and antimicrobial susceptibility testing, the minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), growth curve, and time-kill assays were determined. The biofilm-forming ability of the included pathogens was also assessed, as well as the capacity of nisin to inhibit and eradicate preformed biofilms. Toxicity was assessed using the hemolysis assay. Nisin exhibited predominantly bacteriostatic and transient activity, with greater efficacy during the early stages of biofilm formation. Hemolysis rates remained below the threshold considered toxic, indicating a favorable safety profile for clinical application. In the second project, 25 Staphylococcus aureus isolates obtained from cases of bovine mastitis were evaluated. Antimicrobial susceptibility profile, biofilm production capacity, MIC, MBC, and biofilm inhibition and eradication assays were performed. Nisin demonstrated antimicrobial activity against the evaluated isolates, with a dose-dependent effect and greater impact on inhibiting biofilm formation compared to the eradication of established biofilms. A significant reduction in bacterial viability and biofilm biomass was observed at specific concentrations. In summary, the results indicate that nisin shows potential as an adjuvant strategy for controlling bacterial infections associated with canine otitis externa and bovine mastitis, particularly due to its action on the early stages of biofilm formation. Despite its predominantly bacteriostatic activity and reduced efficacy against mature biofilms, its low toxicity profile and ability to interfere with bacterial persistence reinforce its relevance as a promising alternative in the context of antimicrobial resistance. Instituição: Universidade Federal da Fronteira Sul Tipo: Dissertação 2026-03-13T00:00:00Z https://rd.uffs.edu.br/handle/prefix/9166 Título: Análise radiográfica e caracterização topográfica de lesões traumáticas em mamíferos silvestres atropelados no Sudoeste do Paraná Autor(es): Caon, Emanuel Primeiro Orientador: Braz, Paulo Henrique Abstract/Resumen: Roadkill constitutes the main anthropogenic factor associated with wildlife mortality, with the Atlantic Forest being the ecosystem with the highest number of recorded cases in Brazil. The susceptibility of species to road collisions is directly related to their type of locomotion, ecological and behavioral patterns, as well as seasonal variations in the region. Understanding the incidence and morphology of the most frequent injuries in the species most affected by roadkill allows professionals involved in wildlife rescue and rehabilitation to adopt more accurate approaches, optimizing the chances of recovery and reintegration of individuals into their natural environments. Among the diagnostic methods employed in this context, radiography stands out as a fundamental tool for the detection and characterization of fractures, dislocations, and other osteoarticular alterations, in addition to supporting therapeutic planning and case follow-up. In this context, the present study aimed to quantify the species of wild mammals found run over on the road surface along three highways connecting the city of Realeza, Paraná State, as well as to perform a radiographic study of these animals in order to characterize bone traumas. Traumatic injuries resulting from roadkill were analyzed in 51 neotropical wild mammals belonging to 12 different species. The lesions were topographically classified into four categories: abdomen/pelvis (AP), thorax (TX), head/neck (HN), and extremities (EX). The most prevalent radiological findings were pelvic fractures (67%; n = 34), followed by fractures of cranial bones, including the mandible (55%; n = 28), frontal bone (45%; n = 23), occipital bone (43%; n = 22), maxilla (43%; n = 22), and parietal bone (41%; n = 21). We also determined the frequency of roadkills across the seasons, with spring showing the highest number of occurrences. These results may assist veterinarians involved in the emergency care of wild animals and may also be valuable in forensic investigations where roadkill is considered a possible contributing factor to death. Instituição: Universidade Federal da Fronteira Sul Tipo: Dissertação 2025-12-05T00:00:00Z https://rd.uffs.edu.br/handle/prefix/9165 Título: Respostas fisiológicas e sedativas em Phrynops geoffroanus (SCHWEIGGER, 1812): comparação de dois protocoloas anestésicos com Dexmedetomidina e Cetamina Autor(es): Meznerovvicz, Ademar Francisco Fagundes Primeiro Orientador: Braz, Paulo Henrique Abstract/Resumen: Anesthesia in chelonians presents specific challenges due to the absence of a diaphragm, the restriction of the coelomic cavity by the carapace, and the ability to tolerate prolonged apnea, factors that can compromise the effectiveness of inhalational anesthetics. Therefore, injectable protocols have been extensively investigated for safety and efficacy. The Geoffroy's sidenecked turtle (Phrynops geoffroanus) is a semi-aquatic and diurnal species, widely distributed in South America, recognized as an environmental bioindicator and adaptable to urbanized and hypoxic environments. As reptile metabolism is temperature-dependent, the animals were kept at 28 °C (within the recommended range of 24–32 °C) to ensure adequate physiological and pharmacokinetic stability. This study evaluated the intramuscular combination of dexmedetomidine and ketamine, with reversal by atipamezole, in 25 adult P. geoffroanus. The animals were divided into two groups: HG (dexmedetomidine 0.1 mg/kg + ketamine 10 mg/kg; n = 13) and LG (dexmedetomidine 0.05 mg/kg + ketamine 10 mg/kg; n = 12). Heart rate (HR), respiratory rate (RR), cloacal temperature (CT), behavioral reflexes, and venous blood gases were evaluated at baseline, during chemical restraint, and during recovery. There were no significant differences between the groups at the same time points for HR, RR, and CT, indicating physiological stability at both doses. However, compared to baseline, there were significant reductions in HR and RR, more evident in the HG group. In this group, respiratory rate decreased from 39 ± 13 (12–64) to 7 ± 12 (0–42) breaths/min between 35–45 minutes, returning to 36 ± 10 (17–56) 15 minutes after atipamezole administration. The HG group showed deeper sedation, with significant reductions in head and limb tone, righting and eyelid reflexes, spontaneous movements, and mandibular tone, while the LG group showed mild to moderate sedation. The cloacal reflex did not differ between groups. After reversal, all reflexes gradually returned without excitation, and physiological parameters approached baseline. Blood gas analysis revealed mild alkalinization, with increased pH, reduced pCO₂, and stable bicarbonate, without clinical repercussions. The protocol demonstrated rapid onset, dosedependent sedation, effective reversal, and safe recovery, making it suitable for clinical, experimental, and field use with P. geoffroanus. Instituição: Universidade Federal da Fronteira Sul Tipo: Dissertação 2026-02-04T00:00:00Z