Although studies carried out in the Northern Hemisphere have shown variations in the stallions’ sperm quality between seasons, the same result was not found in the Southern Hemisphere. This is due to some factors, mainly the latitude where the animals are. Therefore, the aim of this research was to evaluate the influence of seasons on the variation of testicular morphometric parameters and its consequent role in hormonal production (serum cortisol, oestrogen, and testosterone values) and seminal quality parameters in stallions kept at low latitudes. Eight stallions were followed for one year, with morphometric measurements of the testes, hormonal assays and semen collections being carried out every 15 days. Semen samples were evaluated using CASA system and flow cytometry. Testicular measurements (length, width, and height) were obtained using ultrasound and radioimmunoassay was used for hormonal assays. The testicular length remained stable throughout the year, while width and height showed variations, mainly in winter (p<0.05). The morphometric measurement that presents the highest correlation with seminal quality parameters was total testicular width. Although a small variation was found in the seminal quality parameters evaluated, there was no impact on seminal quality.

The global tilapia industry has emerged as an important animal protein segment, with production estimated at 6.2 million tons, making it the second most cultivated fish in the world. In Brazil, production is estimated at 579 thousand tons in 2023, with a turnover of more than USD 1,2 billion. In the Federal District (FD), tilapia production is estimated at approximately 1,800 tons per year, which is an important source of income for local farmers and serves as a source of protein for the consumer market in Brasília, the third largest in the country in terms of fish consumption. The general objective of this work was to characterize the commercial production of tilapia in the FD in terms of production, sanitary and epidemiological aspects. The thesis was subdivided into 5 chapters and annexes, with Chapter I consisting of an introduction and each of the other sections representing a paper that will be submitted to a specific scientific journal. Chapter II deals with the productive and sanitary characterization of commercial tilapia farming in the FD between 2021 and 2022, based on a semi-structured questionnaire applied to 112 farmers. The results showed that tilapia farms in the FD generally have a good health infrastructure, as 82.1% of the fish farms were classified as having a biosecurity level of B (low risk) or C (moderate risk) in a weighted points table that assessed the degree of vulnerability to the introduction of pathogens and the risk of dissemination. This study also found significant differences (p<0.05) between some commercial strata, with the closed system fattening group standing out as having superior scores compared to the semi-closed system fattening, young form fish and pay-to-fish farms. The epidemiological study that determined the most frequent tilapia diseases during the period evaluated is presented in Chapter III. By using two complementary epidemiological methods, it was found that the frequency of notifiable diseases in tilapia farms in the Federal District is quite low. Chapter IV evaluates the functionality of a monitoring and instant messaging system for smartphones as part of a surveillance program for notifiable fish diseases. This method proved to be superior to the traditional passive surveillance system and was able to detect the presence of a viral disease in the FD for the first time. Finally, Chapter V presents a literature review on tilapia disease surveillance and the sampling plans used in fish disease monitoring and epidemiological surveys

Intestinal pathogenic strains can affect different animals, including humans, mainly causing diarrhea, and the main virulence factors may be the presence of certain adhesins, toxins and mobile genetic elements. The occurrence of diarrheal diseases related to intestinal pathogenic E. coli is higher in places with poor basic sanitation. The growing antimicrobial resistance of E. coli strains has also been a challenge regarding the treatment of these infections. The occurrence of these bacteria in a variety of animals and the close proximity of tutors and their domestic animals raise concerns about the zoonotic potential of these microorganisms. This search aimed to detect intestinal pathogenic E. coli strains in feces of dogs treated at the Veterinary Hospital of the University of Brasília, a possible correlation between the occurrence of these strains and the basic sanitation of the animal's place of residence and the antimicrobial sensitivity of these isolates. For this, fecal samples were collected from 66 dogs attended at the medical clinic, from which E. coli was isolated from 54 samples. A questionnaire was also applied to the tutors with questions related to information about the animals and basic sanitation conditions in the residence. These 54 strains were tested in PCR for some of the main genes of intestinal pathogenic E. coli: eae, F41, K99, LT-1, LT-2, STa, STb, Stx1 and Stx2. The antibiogram of these strains was performed to test sensitivity to the following antibiotics: amoxicillin, amoxicillin/clavulanic acid, ampicillin, ampicillin/sulbactam, aztreonam, cephalexin, cefepime, ceftizoxime, ceftriaxone, enrofloxacin, gentamicin, imipenem, marbofloxacin, meropenem, sulfazotrim, sulfonamides, tetracycline and tobramycin . Five samples were positive for the presence of the intimin gene (eae) (9.3%). It was identified that of the four residences that had rudimentary pits for wastewater disposal, in two (50%) animals with E. coli eae+ result were identified. Antimicrobial resistance was widely detected in most of the isolates, with penicillin antibiotics associated with β-lactamase inhibitors and fluoroquinolones as those with the highest sensitivity, but still with a significant number of resistant strains. Research on the occurrence of E. coli, including the emergence of new pathogenic and antimicrobial-resistant strains, prevention and control must be continuous and have the concept of one health as central in these approaches, given the complexity of factors that determine this occurrence, with humans, animals and the environment as fundamental pieces for a better understanding and decision-making.

In Brazil, equine infectious anemia (EIA) has been a notifiable disease for the official veterinary service (SVO) since 1981. Due to the requirement to test negative for EIA for equine movement, most of the suspect cases are found with serological testing. The main measures to control and eradicate the disease are segregation and the slaughter of seropositive animals. Several studies have shown that the prevalence of the disease in Brazil is very variable and in many cases it is not possible to identify risk factors due to the low positivity rate. This study aimed to identify the characteristics of establishments with horses and estimate the seroprevalence of EIA in the Federal District -DF. The sample design was devised to target different types of holdings registered with the SVO-DF and identify possible risk factors. A total of 52 stud farms, 51 shared holdings for draft horses, 157 rural farms, 8 riding clubs, 3 veterinary hospitals and 2 military units were sampled, totaling 273 establishments. The sample included 2,482 equines, of which 10 were donkeys, 95 were mules and 2,377 were horses. An epidemiological questionnaire was used to characterize the holdings, covering environmental, organizational and health aspects. It was possible to conclude that rural farms and shared holdings for draft horses, due to their organizational and sanitary characteristics, have the potential to act as reservoirs and spreaders of EIA, respectively. Only these two typologies had animals that reacted to the disease (8/2,482), and the prevalence between them showed no significant difference. Animal prevalence was estimated at 0.65% (95% CI |0.37-1.05%|) and herd prevalence was 2.5% (95% CI |0.99-5.1% |). Animals that had not been tested for the disease over the last year had a higher prevalence of the disease than tested equids. The prevalence as also higher in mules compared to horses.

Chronic Kidney Disease (CKD) is prevalent in elderly cats, often manifesting itself stably over long periods. Identifying parameters signaling the progression of CKD is crucial for early and efficient diagnosis, thereby improving patient prognosis. The objective of this study was to assess whether there is a relationship between parathyroid hormone and other biochemical parameters in cats with chronic kidney disease in stages 2, 3, and 4. Fifteen adult cats, 12 males, and 3 females, were evaluated and divided into three groups: Group II (n=9), Group III (n=3), and Group IV (n=3). All cats underwent anamnesis and physical examination, considering weight, body condition score, age, and breed. For all groups, parathyroid hormone, hematocrit, calcium, phosphorus, urea, creatinine, potassium, systolic blood pressure, and time of survival after diagnosis were assessed. Results indicated that systolic blood pressure was above ideal values. Body condition score varied significantly between groups, highlighting different levels of impairment. Hematometric values remained within normal limits, while ionic calcium varied, indicating possible renal compromise. Phosphorus was elevated in one CKD group, and urea and creatinine showed significant increases in affected groups. Parathyroid hormone (PTH) was elevated in one CKD group. Statistical differences were evident for urea between Group II and Group IV and for creatinine between Group II and Group IV and Group III and Group IV. Correlation analysis did not reveal statistical differences, but variations in correlation coefficients suggested associations between different parameters in the studied groups. The study analyzed the percentage of deaths in cats with chronic kidney disease (CKD), indicating its relation to the severity of the condition and determination of survival. Results revealed that in Group II, the majority of deaths occurred within an interval of 4 to 48 months, affecting 44.44% of the animals. In Group III, all cats died within a period of 16 to 65 months after the diagnosis of CKD. In Group IV, 66.67% of cats died within an interval of 26 to 54 months. In summary, the study provided a comprehensive understanding of the factors involved in the progression of CKD in cats, highlighting the complexity of the disease and the need for a multifaceted approach in diagnosis and treatment.

Bovine brucellosis is a zoonosis of great economic and public health impact. In Brazil, the National Program for the Control and Eradication of Brucellosis and Tuberculosis (PNCEBT) was created in 2001, with the specific objectives of reducing the prevalence and incidence of new outbreaks of brucellosis and tuberculosis and promoting the certification of properties free of brucellosis and tuberculosis and that would offer the consumer products of low health risk. After more than a decade of the creation of the PNCEBT, new strategies were devised, and it became necessary to implement active epidemiological surveillance systems to identify foci normally undetected by clinical signs or by routine control actions. In dairy herds, the tests applied to tank milk can also be appropriate for this purpose, provided that they are previously validated for the purpose for which they are intended. These tests have advantages such as low cost, ease of sample collection and speed in obtaining results. In the present study, the performance of three diagnostic tests for bovine brucellosis in tank milk samples from Santa Catarina (SC) were evaluated: milk ring test (TAL), the ELISA Brucellosis Antibody Test Kit – Tank Milk IDEXX (i-ELISA) and a qPCR developed by the LFDA-MG (PCR). A total of 187 tank milk samples were obtained from herds classified as Free (103) and from herds classified as Infected/Positive (84), all located in the state of Santa Catarina. The data obtained were tabulated and the parameters of interest, sensitivity and specificity of each test, were estimated by a Bayesian latent class model, for two populations and three diagnostic tests, two of them correlated - ELISA and TAL. The posterior estimates for the parameters were reported with 95% credibility. The i-ELISA yielded a sensitivity (Se) of 0.9 [0.73 - 0.99] and specificity (Sp) of 0.99 [0.95 – 1.0]. The TAL presented Se of 0.82 [0.68 – 0.93] and Sp of 0.84 [0.77 – 0.9]. Finally, the Se of qPCR was equal to 0.01 [0.0 – 0.05] and the Sp was 0.97 [0.93 – 0.99]. The results of this study indicate that i-ELISA would be the test of choice for surveillance of bovine brucellosis using samples from milk tanks, whereas TAL is a good alternative. The qPCR evaluated in this study would not be adequate as a tool for detecting infected herds.

Despite the relevance of raptors in the wild animal’s medicine, there is a lack of information on sedative drugs and the use of the intranasal (IN) route in these birds. So, the aim of the present research was to evaluate the chemical restraint of Megascops choliba with midazolam, alone or in association with butorphanol, intranasally. Sixteen adult individuals of the species were evaluated, divided into two groups with eight animals each. In group 1 (G1), 5 mg/kg, IN, of midazolam alone was used, while the birds in group 2 (G2) received the benzodiazepine at the same dose mentioned, associated with 6 mg/kg, IN, of butorphanol. Birds were evaluated for responses to environmental stimuli, duration of effects and monitoring of physiological parameters. Deep sedation was observed in eight (8/8; 100%) birds belonging to G1 and five (5/8; 62.5%) to G2. The association of butorphanol with midazolam did not promote beneficial effects in terms of duration or intensity, and there was a significant reduction in heart rate, respiratory rate and cloacal temperature for both groups.

Regional nerve block techniques have been improved in order to treat pain in clinical, emergency and surgical situations. This technique has huge relevance since it results in total remission of nociception through perineural local anesthestic deposition. When it comes to wildlife, there are few studies describing nerve blocking techniques. In avians, regardless of studies about brachial plexus nerve blockade - responsible for innervation of toracic limbs, there is no description of lumbar and sacral plexus approach - responsible for sensorial and motor innervation of hind limbs. Thus, this study aims to describe brachial, lumbar and sacral plexus nerve blocking approaches in Amazona aestiva, considering its potential influences by quantitative and qualitative variable analysis. This study is a randomized controlled trial prospect carried out with 40 Amazona aestiva corpsi, whose deaths were caused by natural events. They were donated, frozen, by CETAS-DF. Volumes of 0,25 and 0,4 mL/kg 1% blue methilene were injected using two different techniques: palpation guided and ultrasound guided. Both techniques were used to assess brachial, lumbar and sacral plexus, bilateraly. The animals were dissected in order to evaluate its efectiveness, being classified in efective, parcial efective and inefect. Qualitative and quantitative variables such as body score, weight, sex, volume injected, antimere, metric of needle inserction, choosen technique and operator were considered for statistics.

The aim of this work was to carry out the microbiological characterization of swine carcasses from the Federal District region by counting Enterobacteriaceae, Escherichia coli and Total Coliforms, searching for Salmonella spp. and Listeria monocytogenes and to detect of virulence genes stx1, stx2 and eae for Escherichia coli, as well as antibiogram and verification of biofilm formation of the isolates. For this, swabs were collected at 5 points on the carcass (leg, loin, belly pork, armpit and jowls pork) and in 6 stages of the technological process of slaughter, being them after bleeding, after passing through the epilator, after manual toileting in the dirty area. , before and after evisceration and after the final carcass washing, before cooling the carcasses, in 2 slaughterhouses between September 2019 and July 2021. In the counts of Enterobacteriacea, Escherichia coli and total Coliforms, it was possible to identify the main contamination points in each slaughterhouse in the 3 collections carried out, being them after bleeding and after evisceration in the slaughterhouse A, after the manual toilet and after evisceration in the slaughterhouse B in the 1st collection, and in the 2nd collection the step after the evisceration for the 3 microorganisms. Escherichia coli were isolated in the two slaughterhouses and Salmonella spp. and Listeria monocytogenes only in slaughterhouse B. Antimicrobial multidrug resistance was detected in most E. coli isolates, with higher frequencies of resistance to amoxicillin, ampicillin, chloramphenicol, sulfonamides and streptomycin. The virulence genes eae, stx1 and stx2 were also detected in the E.coli isolates, with 3 isolates presenting the 3 genes together and antimicrobial multiresistance to at least 6 classes of antimicrobials. Furthermore, a high frequency of moderate and strong in vitro biofilm formation was detected in E.coli isolates. There was isolation of Salmonella spp. in the stage after bleeding in one of the slaughterhouses, presenting antimicrobial multiresistance to at least 3 classes of antimicrobials and weak ability to form biofilms or did not form biofilms in vitro. In this same slaughterhouse there was also the isolation of Listeria monocytogenes in the carcass. The isolates showed antimicrobial resistance to 4 tested antimicrobials, and were weak biofilm formers at temperatures of 10ºC, 24ºC and 37ºC, with a strong forming isolate at 37ºC. As this is the first study of microbial characterization in swine carcasses in DF, the identification of virulent strains of Escherichia coli, multiresistant with moderate to strong capacity to form biofilms, as well as the isolation of Salmonella spp. and Listeria monocytogenes with antimicrobial resistance and the ability to form biofilms demonstrate potential risks to public health.

Over the years, felines have gained increasing acceptance as pets, which is reflected in the growth

of the population of these pets (RECHE JUNIOR 2018). The use of stem cells, also called cell therapy, has great potential for

applicability to feline diseases, but there are still several questions to be answered regarding its use, including its 

safety(QUIMBY 2018). Thus, the present study aimed to evaluate the safety of using halogenated mesenchymal

stem cells(MSCs) intravenously by monitoring physical parameters (mucosal staining, lymph node examination, 

heart and respiratory rate, rectal temperature). and hematology of a group of 8 healthy cats. Applications were 

carried out atthe Clinic School of Veterinary Medicine of FACISA to monitor possible adverse reactions. Among the 

physical parameters evaluated previously and throughout the study, no relevant changes were observed. As for the 

hematological parameters, the results indicate that in the first week, the only parameter whose average showed a 

significant reduction was Alkaline Phosphatase. Two weeks after the application of CTM, three parameters showed a

significant reduction in the average in relation to the levels observed before the beginning of the experiment, which

are Hematocrit, Hemoglobin and Creatinine. After 3 weeks of MSC application, all parameters returned to levels 

close to the original values. The present study points to the safety of using allogeneic MSCs intravenously in cats at

the established dose.

Present in cell therapy, mesenchymal stem cells (MSC) are undifferentiated cells, defined by their great capacity for proliferation, self-renewal and regeneration after injury. They can be classified in different ways, according to their tissue of origin, such as embryonic, adult, and induced pluripotent stem cells, and their capacity for cell differentiation, such as totipotent, pluripotent, or multipotent cells. Initially, it was thought that MSC exerted their therapeutic effect by migrating to the site of injury, inserting themselves and, later, differentiating into desired cells for tissue regeneration. However, studies have indicated that the therapeutic benefit of MSCs is attributed not only to their differentiation, but also to the factors they secrete, such as growth factors, chemokines and cytokines, in addition to releasing numerous extracellular vesicles that participate in tissue regeneration through transfer information to damaged cells or tissues. The present work aims to evaluate the healing effect of cutaneous wounds, produced on the back of three healthy pigs, with the use of different concentrations of isolated extracellular vesicles, cultivated and characterized through mesenchymal stem cells from swine adipose tissue, during twenty-eight days. Sixteen cutaneous wounds were made on the back of each pig, in duplicate, we used two different concentrations of extracellular vesicles, one of healing base, one of conditioned medium, positive control that was used a commercial ointment and negative control, using solution saline. Quantitative data were measured through wound retraction and qualitative data were performed through histological slides. Concluding significant therapeutic effect on tissue repair of extracellular vesicles.

This thesis was divided into a literature review (Chapter 1) and five scientific articles. The general results of the thesis are presented in scientific article 1 and 2. In scientific article 1, 204 white-eared opossum necropsy protocols from the routine of the Veterinary Pathology Laboratory of the University of Brasília (LPV-UnB) and from the veterinary hospital for wild animals at UnB from January 2010 to June 2020. The main causes of death were traumatic, infectious, parasitic and metabolic, respectively. A case of brain toxoplasmosis and a pleomorphic sarcoma were recorded and diagnosed by immunohistochemistry. In scientific article 2, anatomical aspects, lesions of little clinical significance and post-mortem changes recorded in the necropsy routine from August 2018 to June 2020. The following anatomical aspects were listed as baby carrier, mammary papillae, epipubic bone, bifid reproductive tract, scrotal pouch in the inguinal location and cranial to the penis, semi-prehensile tail, absence of claws on the first digit of the pelvic limb, absence of the quadrate hepatic lobe, filiform tongue papillae, absence of hair and labial structure in puppies. As lesions of little clinical significance, infestations by helminths and protozoa such as Physaloptera sp., Sarcocystis sp. and Cruzia tentaculata, smooth muscle hyperplasia in pulmonary arterioles, evidence of the hepatic lobular pattern, body skin abrasions and tail end laceration. As the most common autolytic and putrefactive post-mortem alterations, pulmonary emphysema, intestinal tympanism and pseudomelanosis, pallor of organs and detachment of the epidermis (maceration) were mentioned. Scientific articles 3, 4 and 5 are case reports of specific conditions found in the period and mentioned in scientific article 1. It is concluded that trauma, septicemia and neonatal triad are important causes of death in white-eared skunks in the District Federal. White-eared opossums are susceptible to Toxoplasma gondii and may act as amplifiers of the zoonotic agent in the environment. Finally, the knowledge of anatomical particularities, lesions of little clinical significance and post-mortem changes in domestic and wild animals are useful for the correct diagnostic interpretation and forensic investigations in these animals. However, further characterization work is also needed through the sharing of routine diagnostic experiences.

The objective of this work was to describe the epidemiological situation of rabies caused by exposure to wild canids in Northeastern Brazil, as well as to evaluate the knowledge, attitudes and practices of the population regarding the risk of exposure to the disease by this species. Chapter 1 presents the epidemiological situation of rabies in the Northeast region, discussing official data from the last 20 years. A descriptive study of rabies cases in wild canids was carried out, as well as cases of rabies in dogs, cats and humans associated with the same viral variant, adapted from wild canids (Cerdocyon thous). In chapter 2, the results and conclusions reached by a qualitative and quantitative study are described, approaching knowledge, attitudes and practices of the population of areas of transmission of rabies by wild canids in the state of Ceará, in the northeast of Brazil. Chapter 3 brings the newsletter already published by the Ministry of Health, with information aimed at health professionals and the general population about rabies transmitted by wild canids, where the reservoirs, the epidemiological situation and the cases of rabies in animals were discussed. and humans between 2016 and 2021, as well as popular knowledge evaluated by the health service in areas of focus in the states of Rio Grande do Norte and Bahia. This thesis described the main characteristics of rabies in wild canids in Northeastern Brazil and highlighted the importance of epidemiological surveillance given the extension of the area of occurrence and the population contingent exposed to the disease. The increase in the number of cases over the last few years and the diversity of affected hosts, including the record of human cases, are noteworthy. Profiling the knowledge, attitudes and practices of the exposed population can help guide public policies in health, health education and risk communication, in line with the local population profile.