Renal resistive index in obese and non­obese cats.

This study aimed to compare renal function between obese and normal­weight healthy cats, using intrarenal resistive index (RI), serum symmetric dimethylarginine (SDMA), and serum creatinine, and to identify the variables that might influence intrarenal RI. Thirty crossbred client­owned cats met the inclusion criteria and were allocated into two groups: Control and Obese. Body weight, body mass index (BMI), body condition score (BCS), SAP, serum SDMA, urea, and creatinine were evaluated. B­mode and Doppler ultrasound of the kidneys were done. RI evaluation was in the interlobar artery. SDMA and intrarenal RI were compared between groups, also considering the gender of the cats. A correlation analysis between intrarenal RI with the other parameters was performed. SDMA was higher in the Obese group. Intrarenal RI was higher in females than males in the Obese group. Obese females presented higher RI and SDMA than Control females. A positive correlation was observed between RI, age, body weight, and BMI. Six obese cats (40%) showed increased RI. The increase in body weight, BCS, and BMI resulted in a simultaneous increase in RI and SDMA. The RI may assist in monitoring renal function, and may be associated with preclinical kidney changes in obese cats.

Neonatal sepsis in dogs: Incidence, clinical aspects and mortality.

The neonatal period in dogs remains associated with high mortality rates. Sepsis is the main cause of neonatal losses during the first three weeks of life. Additionally, failure in the clinical assessment and early diagnosis of sick newborns is still common, leading to inadequate care, which contributes to a high mortality rate. Thus, the objective of this study was to describe the incidence of sepsis in canine newborns, the clinical aspects involved, the main isolated bacterial agents and mortality rates to facilitate clinicians' early recognition of this condition. Of the 152 litters and 762 neonates evaluated, 14.8% (113/762) had sepsis or septic shock, and the mortality rate among affected puppies was 25.6% (29/113). Among the puppies with sepsis that died, early mortality (0-2 days of age) occurred in 69% (20/29) of affected neonates, and late mortality (3-30 days of age) occurred in 31% (9/29) of affected neonates. Significant differences (p < 0.0001) in clinical parameters (heart and respiratory rates, blood glucose, body temperature, peripheral oxygen saturation and reflexes) were noted among healthy neonates and neonates with sepsis and septic shock. The main and most relevant clinical signs were apathy, a reduced sucking reflex, diarrhea, the neonatal triad, failure to gain weight, bradycardia, dyspnea, cyanotic mucous membranes, body erythema, reduced peripheral oxygen saturation, cyanosis and tissue necrosis in the extremities. The mother may have been the main source of infection for 87.6% (99/113) of neonates with sepsis. Most infections were transmitted during pregnancy (68%, 77/113) in cases of neonatal sepsis. The major source of infection for neonates was the uterus, followed by breast milk and maternal oropharyngeal secretions. The most frequently isolated bacterial agent was Escherichia coli, accounting for 25.6% (29/113) of sepsis cases. The morbidity and mortality of neonatal sepsis in dogs is high. The clinical evaluation and diagnosis of sepsis in neonates differ from those in adult animals. Thus, knowledge of the neonatal particularities of sepsis is essential for proper clinical management and greater survival of these patients.

Use of cardiac troponin I (cTnI) levels to diagnose severe hypoxia and myocardial injury induced by perinatal asphyxia in neonatal dogs.

Prolonged perinatal asphyxia and subsequent severe hypoxia are the main causes of mortality in neonatal dogs in the first days of life. In medicine, specific cardiac biochemical markers, such as troponin I, are used to diagnose ischemic and nonischemic myocardial injury in asphyxiated newborns after birth. Thus, the objectives of this study were to compare the levels of cardiac troponin I (cTnI) between asphyxiated and nonasphyxiated newborn dogs and evaluate the correlations of cTnI levels with the modified Apgar score, the levels of oxygen saturation, blood glucose, and lactatemia, and blood gas parameters. This study aimed to determine the possible use of cTnI as a marker of severe hypoxia and myocardial ischemic injury in neonatal dogs. Fifteen animals in a eutocic vaginal delivery group (VG), 15 animals in a cesarean section group (CG), and 13 animals in a hypoxia (asphyxiated) group (HG) were evaluated. The animals in the asphyxiated group were from dystocic deliveries and born by vaginal delivery or cesarean section. All groups were evaluated at birth and after 60 min. The newborns in the VG and CG exhibited mixed acidosis (respiratory acidosis due to increased partial pressure of CO2 (pCO2) and metabolic acidosis due to reduced pH and bicarbonate (HCO3) levels, base excess/deficit in the extracellular fluid compartment (BEecf), and increased lactate levels) due to transient physiological hypoxemia at birth. The cTnI levels in the VG and CG were within the reference standards for healthy dogs. No correlations between cTnI level and the other parameters were observed in the VG and CG. Newborns in the HG exhibited prominent mixed acidosis (p < 0.05) due to severe hypoxemia. The Apgar score and blood gas parameters showed that these dogs were born asphyxiated, and they presented low vitality and the need for resuscitation maneuvers. The cTnI levels in the HG were significantly higher than those in the VG and CG (p < 0.05) and above the reference standards for healthy dogs, which indicated ischemic myocardial injury. The cTnI level was negatively correlated (p < 0.05) with the parameters Apgar score, heart rate, peripheral oxygen saturation (sO2) level, reflex score, and total carbon dioxide (TCO2) level and positively correlated (p < 0.01) with lactate level. This study showed that asphyxiated newborn dogs have higher serum cTnI levels than nonasphyxiated newborn dogs; thus, the cTnI can be used as a marker of severe hypoxia and ischemic myocardial damage in newborn dogs.

Heart rate variability in Dorper sheep in the fetal and neonatal periods until 120 days of age: Use of the technique in the field.

The evaluation of the autonomic cardiac functions may be performed through the analysis of the heart rate variability. Heart rate variability is defined as the fluctuations in the heart rhythm or rate, and represents a useful tool in the evaluation of the autonomic nervous system through the sympathetic and parasympathetic components, as well as its balance and its reflexes on the cardiorespiratory control system. Fetal electrocardiography provides important information regarding the well-being of the fetus since, in human fetuses, there are changes in the behavior of the fetal heart rate during the second and third trimesters of pregnancy due to an increase in parasympathetic activity. Therefore, considering the importance of evaluating fetal viability, this study aims at evaluating the behavior of fetal heart rate and heart rate variability in Dorper sheep, as well as the activity of the autonomic nervous system during fetal life and in newborn lambs. The species is often used in experimental studies and autonomic nervous system activity is a prognostic index, therefore, the diagnosis of modifications in the sympathovagal balance may represent an early index for fetal viability and well-being in lambs. The analyses were performed in 10 Dorper sheep during pregnancy and in 10 lambs after birth until 120 days of age. There was a decrease in the fetal heart rate and heart rate variability indexes during the fifth month of pregnancy, but without statistical significance for the period evaluated. The heart rate of the lambs decreased gradually until they were 21 days old. The indexes SDNN (standard deviation of RR intervals) and RMSSD (square root of the mean of successive differences between adjacent RR intervals) diverged according to age, being high at day 60. Fetal viability is relevant in sheep fetuses to avoid losses during pregnancy and risks to the health of the mother. In the species, there seems to be a predominance of parasympathetic activity starting from the 21st day of age. Heart rate variability may be employed as a tool in the evaluation of the fetus and development of lambs, since changes in its behavior may represent an adverse effect to fetal and neonatal health.

Evaluation of heart rate variability and behavior of electrocardiographic parameters in dogs affected by chronic Monocytic Ehrlichiosis.

Canine Monocytic Ehrlichiosis (CME) is a systemic disease prevalent in the entire world caused by the obligate intracellular bacteria Ehrlichia canis. The occurrence of myocarditis with a high prevalence of arrhythmias in dogs affected by this disease in the cytopenic phase has already been proven. This study aims to evaluate the concentrations of CK MB, cTnI and NT-proBNP in dogs affected by Ehrlichia canis in the chronic phase since the intense stimulation of the immune system can lead to myocarditis; to evaluate if the condition can lead to arrhythmic events and, if so, define their frequency and classification through conventional and ambulatory electrocardiogram tests (Holter method) for a period of 24 hours; to analyze heart rate variability in the time domain and whether the condition can lead to autonomic imbalance; and to determine the survival rate of affected dogs, identifying possible risk factors for mortality at this stage of the disease. For this purposes, we evaluated clinical, hematological and biochemical data, as well as the concentrations of cardiac biomarkers Creatine Kinase-MB (CK MB), Cardiac Troponin I (cTnI) and N-terminal pro-peptide natriuretic type B (NT-proBNP). We also analyzed conventional and ambulatory electrocardiography (24-hour Holter) and heart rate variability (HRV) in 20 dogs afflicted by cytopenic CME in the chronic phase of the disease (G1) and compared the results with a control group comprised of ten healthy dogs (G2). G1 was monitored during the treatment for 28 days, during which eight (8) of the 20 infected dogs died (40%). Anorexia, vomiting, fatigue, hypoalbuminemia, heart murmurs and increased concentrations of alanine aminotransferase (ALT) and alkaline phosphatase (ALP) were common clinical signs. The mean concentrations of cTnI and CKMB were significant (0.24 ng / mL ± 0.5, 229 ± 205 IU / mL) in comparison to the control group (0.042 ± 0.07 ng / mL, 126 ± 46.12 IU / mL). No significant differences were observed between NT-proBNP concentrations in G1 (135.46 ± 29.7) and G2 (138.28 ± 19.77). Nine of the twenty dogs (45%) presented a high frequency of arrhythmias during 24-hour recording, ranging from first and second-degree atrioventricular block, ventricular and supraventricular ectopic events and sinus tachycardia. No sinus pause was observed. One dog had 120 episodes of unsustained ventricular tachycardia and two episodes of sustained ventricular tachycardia. The short-term and long-term HRV data, represented by SDNN (ms), SDANN (ms) and pnn50 (%) were also significant lower (83 ± 65, 56.05 ± 37.3 and 14.56 ± 20, respectively) in comparison to the healthy animals (268 ± 74.6, 168.3 ± 39.14 and 55.87 ± 12.8, respectively). These results suggest that cytopenic CME is characterized by an arrhythmogenic component and intense stimulation of the sympathetic autonomic nervous system in the heart, reflecting an imbalance in the activity of the ANS.

Conventional and Holter Electrocardiographic Assessment of Dogs Infected Naturally With Acute Canine Monocytic Ehrlichiosis.

Canine Monocytic Ehrlichiosis (CME) is a disease of worldwide distribution caused by the bacteria Ehrlichia canis, appearing primarily in hot climates due to the massive prevalence of its vector, the tick Rhipicephalus sanguineus. Previous studies have shown that dogs afflicted by CME in the chronic phase can develop infectious myocarditis, arrhythmias, and alterations in heart rate variability (HRV), but there are few studies correlating cardiac diseases with the acute phase of CME. This study aims at assessing electric cardiac alterations and HRV in the time and frequency domains during the acute phase of CME. This study assessed 22 animals divided into 2 distinct groups: the control group, comprised by 10 healthy dogs, and the sick group, comprised of 12 dogs infected naturally with ehrlichiosis which presented clinical and hematological signs compatible with the acute phase of the disease. The animals underwent conventional and Holter electrocardiographic evaluations, systolic blood pressure measurement, complete blood count and biochemical assays (urea, creatinine, alanine aminotransferase (ALT), alkaline phosphatase (AP), and gamma glutamyl transferase (GGT)). The sick group presented higher activity in the sympathetic nervous system than in the parasympathetic nervous system, manifest as a significant increase in mean heart rate and a reduction in the HRV indexes for the time and frequency domains. The frequency-domain HRV indexes presented sympathetic prevalence during the sleep and vigilance states. Sinus tachycardia was the predominant heart rhythm in 58.33% of the animals. The mean systolic blood pressure diverged between the groups and no significant arrhythmias were observed during monitoring. The serum concentrations of urea, creatinine, AP, ALT, and GGT were within the established reference values for the species. We observed no indication that there was enough time during the acute phase for the disease to evolve in a way that resulted in arrhythmias, as is common in the chronic phase, but we observed that animals in the acute phase already present reduced HRV indexes.

Incidence of congenital malformations and impact on the mortality of neonatal canines.

Canine congenital malformations are structural or functional abnormalities of organs present at birth that possibly interfere with the viability of newborns, thus contributing to neonatal mortality. This study evaluated and described the incidence of congenital malformations in neonatal dogs and determined the mortality rates among those affected. Of the 178 litters and 803 newborns included in the study, 24.7% (44/178) of the litters presented neonates with congenital malformations. The total rate of neonates that presented malformations was 6.7% (64/803). The total mortality rate in newborns with congenital defects was 5.4% (44/803), representing 68.7% (44/64) of the deaths observed among those affected. The early (0-2 days old) and late (3-30 days old) mortality rates among the affected neonates were 61.4% (27/44) and 38.6% (17/44), respectively. In total, 27 malformations were recorded, and the most common congenital defects were cleft palate 2.8% (23/803) and hydrocephaly 1.5% (12/803), either alone or associated with other malformations. The malformations were recorded in 15 breeds: Pug, Miniature Pinscher, Rottweiler, Pitbull, French Bulldog, English Bulldog, Dachshund, Labrador Retriever, Lhasa Apso, Poodle, German Spitz, Yorkshire Terrier, Shih-tzu, Brazilian Terrier and mixed breed. One case of exposure to a teratogenic agent was reported, but no maternal exposure to teratogens during gestation was reported with the other litters. The occurrence of congenital defects may be related to genetic factors since the highest incidence of malformations (84.4%) was observed in purebred dogs.

Scaling Relationships Among Heart Rate, Electrocardiography Parameters, and Body Weight.

Although heart rate (HR) is one of the most important clinical parameters determined via physical examinations, little information is available on the normal HR in dogs, which may be related to the high variability of body weight (BW) in this species. HR is determined by the discharge rate of the sinus node, which is dependent on the autonomic nervous system and the release of catecholamines. The allometric relationship between BW and HR in different species has been described as inversely proportional; however, this relationship has been refuted. Certain authors have reported that the relationship between HR and BW in dogs is based on temperament as well as sympathetic autonomic stimulation of the sinus node in small breeds compared with large breeds. The aim of this study was to analyze the effects of weight, sex, age and temperament on the HR, heart rate variability and serum catecholamine (epinephrine and norepinephrine) levels in dogs. We evaluated 48 adult dogs of both sexes and various breeds and ages and divided the dogs into 5 BW groups: <5kg (n = 8), 5-10kg (n = 10), 10-25kg (n = 10), 25-45kg (n = 10), and >45kg (n = 10). The measured parameters were HR, breath rate (BR) and body temperature. We also performed an ambulatory electrocardiogram and electrocardiography (ECG) test for 24 hours (Holter monitor) and determined the serum levels of the catecholamines epinephrine and norepinephrine. We observed correlations between HR and sex; differences among the weight groups with respect to ECG variables and epinephrine levels; and differences among the temperament categories for certain clinical parameters, such as HR and BR. Age affected the R wave amplitude, and an allometric relationship was not observed between HR and BW in the dogs. Our results indicated that weight was associated with variations in the ECG variables; age and sex were associated with variations in HR; and temperament had a significant influence on the HR and BR of the dogs.

Routine Screening Examinations in Attendance of Cats With Obstructive Lower Urinary Tract Disease.

This study evaluates the clinical findings obtained in routine screening examinations in cats with obstructive feline lower urinary tract disease at the time of service. Twenty-six cats with urethral obstruction were assessed by physical examination, blood pressure, electrocardiogram, and laboratory tests. Cats with signs of obstruction less than 36 hours before the service were in a state of alert, with body temperature and heart rate higher compared with cats in lethargy and stupor, obstructed up to 36 hours. The results revealed that 30.76% of the cats were hypertensive (>140mmHg). Arrhythmias were found in 15.38% of the cats with potassium >8.5mEqL. Creatinine, phosphorus, magnesium, potassium, and lactate concentrations were higher in cats obstructed more than 36 hours. All these data claim that a protocol of examinations should be established for obstructed cats, principally to stabilize the cat before the anesthesia for unobstruction.