Adipose tissue is a metabolic and endocrine organ, and its adipocytes can synthesize and secrete extracellular vesicles (EVs), thus allowing intercellular communication. EVs are nanoparticles that transport lipids, proteins, metabolites, and nucleic acids (mRNA and microRNAs). MicroRNAs (miRNAs) are small, non-coding RNAs that regulate gene expression. miR-132, miR-26b, and miR-155 are associated with obesity, lipid metabolism and adipogenesis. The aim of this study was to evaluate the enriched EVs fraction containing miRNAs (miR-132, miR-26b, and miR-155) in serum from obese female dogs. Thirty-two neutered females in good general condition were recruited, including 21 obese and 11 healthy controls. The initial evaluation of the females included a general physical examination and laboratory tests. Small EVs (sEVs) were isolated from whole blood by serial centrifugation and ultracentrifugation, and nanoparticle analysis was used to determine the size and concentration of serum sEVs. miRNAs were extracted from sEVs enriched fraction and analyzed by real-time polymerase chain reaction. Obese female dogs with hypertriglyceridemia showed an increase in the sEVs concentration and in the expression of miR-132 and miR-26b in sEVs enriched fraction. No changes were observed in the group of obese female dogs with normal serum biochemical profile and in relation to miR-155 expression. These results suggest that obese female dogs with hypertriglyceridemia may present alterations in sEVs and in the expression of miRNAs related to lipid metabolism and adipogenesis.

Background:The Vertebral Heart Size (VHS) method sets standards for the evaluation of dog's heart size from the comparison of the cardiac dimension with the length of the thoracic vertebrae through radiographic study. Electrocardiogram (ECG) is widely used in veterinary medicine for the evaluation of electrical conduction system of the heart; however, the increase of duration and amplitude of the ECG waves can suggest the increase of cardiac chambers in dogs. The scientific literature presents electrocardiographic and VHS values for dogs of different breeds and sizes; however, there is little information on the correlation of these parameters. Therefore, the aim of this study was to evaluate the amplitude and duration of ECG waves, thoracic morphometry and VHS values, in order to correlate these parameters in clinically normal dogs. Materials, Methods & Results:Twenty healthy dogs (11 females and 9 males), without breed distinction, medium sized (14.46 ± 2.92 kg) and aged between 1 and 8 years, were evaluated through physical examination, digital ECG (frontal and precordial leads) and thorax X-ray in right lateral (RL), left lateral (LL) and ventrodorsal (VD) projections. Thoracic morphometry and VHS measurements were determined as previously described. Clinical and ECG parameters were compatible with the references in all dogs evaluated. Dogs presented thorax intermediate (75%) with the depth and width ratio (D/W ratio) > 1.0. Some individual VHS values were higher than the references and the mean VHS values in VD projection was higher than in RL and LL projections (n = 20; P < 0.05). Female and male dogs did not differ among the evaluated parameters. A positive correlation was observed between thoracic morphometry and body weight (r ≥ +0.70; P < 0.001) and a negative correlation was found between the D/W ratio and VD VHS (r = -0.62; P < 0.05). No significant correlations were observed between the age, ECG parameters, thoracic morphometry and VHS measurements. Discussion: The majority of dogs presented intermediate thorax, a common characteristic for healthy dogs of different breeds. Some dogs had higher VHS values in different projections, when compared to references. The same has been reported by others authors for diferent breeds. However, there is no consensus about VHS values for all sexes, breeds and physical conformations in dogs. In agreement with other authors, the mean value of VD VHS was higher in relation to RL and LL VHS; however, RL and LL VHS did not differ. Positive and significative correlations were observed between body weight and thorax depth, and between body weight and thorax width, confirming that larger dogs had greater thoracic measurements. The thorax type could influence the VHS, when this parameter is determined by VD projection, because was observed a negative and significative correlation between the D/W ratio and VD VHS. So, the dogs with a deeper thorax may have lower VHS values. The correlation between VHS measurements and duration and amplitude of the ECG waves was weak, possibl...

parte dos requisitos para a obtenção do título de Mestre em Ciências.

Background: Hemostatic alterations have already been well characterized in humans with body fat excess, being included in the list of obesity related comorbidities. Overweight and obesity are common in dogs; however, there is little information about the blood coagulation parameters in dogs with these conditions. The aim of this study was to compare hematological and coagulation parameters between lean dogs and overweight or obese dogs, including platelets count; prothrombin time (PT); activated partial thromboplastin time (aPTT), coagulation time (CT) and plasma fibrinogen concentration. Materials, Methods & Results:A total of 22 dogs (aged 1 to 10 years, neutered) were evaluated, 10 of them presented ideal body condition score (BCS 4-5) and formed the group 1 (control) and 12 were overweight or obese (BCS 7-9) and formed the group 2. The dogs were submitted to clinical evaluation and then to blood collection for the following laboratory tests: blood count (performed on automatic analyzer), quantification of plasma proteins by refractometry, determination PT, aPTT and plasma fibrinogen concentration using specific commercial kits, and CT by Lee-White method. Compared to group 1, group 2 presented a lower leukocytes and lymphocytes counts (P < 0.05) and a higher concentration of plasma fibrinogen (P = 0,026), but compatible with reference values. No difference was observed in the erythrogram, platelets count, total plasma protein concentration, PT, aPTT and CT between the groups. BCS was negatively correlated with leukocytes (r = -0.45) and lymphocytes (r = -0.60) counts and positively with plasma fibrinogen concentration (r = +0.56). Discussion: The reduction in lymphocytes led to a lower leukocytes count in the dogs of group 2. The migration of peripheral blood lymphocytes to adipose tissue has been reported in the early phase of the inflammatory process induced by obesity and could justify the reduction of circulating lymphocytes in overweight or obese dogs evaluated in this study; however, cytopathological assessment of adipose tissue was not performed. Fibrinogen has to be converted to fibrin for clot formation, so the concentration of this plasma protein is an important parameter for the evaluation of hemostasis. However, there are reports of increase in plasma fibrinogen as a result of infammatory processes. In group 2, formed by dogs with overweight or obese, the higher value of plasm fibrinogen concentration, associated with lower lymphocyte count, may suggest an early-stage inflammatory process. Similar results were described in obese humans, but also evidenced in obese dogs. Supporting this suggestion, the correlation analysis indicates that the higher the body fat excess (estimated by the BCS), the higher the fibrinogen concentration and the lower the lymphocyte count in evaluated dogs. Despite the higher concentration of plasma fibrinogen in group 2, no change was observed in the hemostasis of overweight or obese dogs, due to the normal values for platelets count, PT, aPTT and CT, excluding a hyperco...