Sedative and electrocardiographic effects of low dose dexmedetomidine in healthy cats / Efeitos sedativos e eletrocardiográficos da baixa dose de dexmedetomidina em gatos saudáveis

In feline veterinary practice sedation is often needed to perform diagnostic or minimally invasive procedures, minimize stress, and facilitate handling. The mortality rate of cats undergoing sedation is significantly higher than dogs, so it is fundamental that the sedatives provide good cardiovascular stability. Dexmedetomidine (DEX) is an α2-adrenergic receptor agonist utilized in cats to provide sedation and analgesia, although studies have been utilized high doses, and markedly hemodynamic impairments were reported. The aim of this study was to prospectively investigate how the sedative and electrocardiographic effects of a low dose of DEX performing in cats. Eleven healthy cats were recruited; baseline sedative score, systolic arterial pressure, electrocardiography, and vasovagal tonus index (VVTI) were assessed, and repeated after ten minutes of DEX 5μg/kg intramuscularly (IM). A smooth sedation was noticed, and emesis and sialorrhea were common adverse effects, observed on average seven minutes after IM injection. Furthermore, electrocardiographic effects of a low dose of DEX mainly include decreases on heart rate, and increases on T-wave amplitude. The augmentation on VVTI and appearance of respiratory sinus arrhythmia, as well as sinus bradycardia in some cats, suggesting that DEX enhances parasympathetic tonus in healthy cats, and therefore will be best avoid in patients at risk for bradycardia.(AU)

Na rotina clínica da medicina veterinária felina a sedação é frequentemente requerida para realização de procedimentos diagnósticos ou minimamente invasivos, para minimizar o estresse e facilitar o manuseio dos pacientes. A taxa de mortalidade de gatos submetidos à sedação é mais elevada do que em cães, por esse motivo, é fundamental que os sedativos confiram estabilidade hemodinâmica. A dexmedetomidina (DEX) é um α2-agonista utilizado em felinos para promover sedação e analgesia, porém os estudos têm utilizado doses elevadas, e com isso prejuízos hemodinâmicos importantes foram relatados. O objetivo desta investigação foi avaliar os efeitos sedativos e eletrocardiográficos da baixa dose de DEX em gatos. Para tal, onze felinos saudáveis foram recrutados, foram obtidos valores basais para escore de sedação, pressão arterial sistólica e eletrocardiografia, além do índice de tônus vaso vagal (ITVV). Após dez minutos da aplicação intramuscular (IM) de DEX 5μg/kg todos os exames foram repetidos. Após a DEX, sedação suave foi detectada, e a êmese e sialorreia foram efeitos adversos comuns, observados em média 7 minutos após a injeção IM. Ademais, os principais efeitos eletrocardiográficos foram redução na frequência cardíaca e aumento na amplitude da onda T. O ITVV mais elevado e surgimento de arritmia sinusal respiratória, bem como bradicardia sinusal em alguns gatos, sugerem que a DEX eleva o tônus parassimpático, e por esse motivo deve ser utilizada com cautela em pacientes com predisposição à bradicardia.(AU)

Dexmedetomidine low dose followed by constant rate infusion and antagonism by atipamezole in isoflurane-anesthetized cats: an echocardiographic study.

OBJECTIVE: To investigate the effects of a low dose of dexmedetomidine (DEX) followed by constant rate infusion (CRI) and reversal with atipamezole on systolic and diastolic functions in isoflurane-anesthetized healthy cats. STUDY DESIGN: Prospective cohort study. ANIMALS: A group of 11 client-owned adult cats. METHODS: Baseline transthoracic echocardiography (TTE) was performed, followed by intramuscular (IM) administration of DEX (5 µg kg-1). After 10 minutes, sedation was scored, adverse effects were recorded and another TTE performed. Approximately 40 minutes after DEX administration, anesthesia was induced by isoflurane mask and maintained with 1.2% end-tidal isoflurane and DEX CRI (1 µg kg-1 hour-1) for 80 minutes. Physiological variables were recorded every 10 minutes, and TTE was repeated 10, 30 and 60 minutes after the start of anesthesia. CRI was stopped, atipamezole (30 µg kg-1) was administered IM and a final TTE was performed after 10 minutes. Repeated measures over time were submitted to one-way analysis of variance or Kruskal-Wallis test according to data distribution; significance was assumed at p < 0.05. RESULTS: After DEX premedication, mild sedation and a slight but significant increase in systolic arterial pressure occurred, and vomiting was a common adverse effect. The cardiac output (CO) and heart rate decreased during anesthesia, with no changes after administration of atipamezole. Trivial valvular insufficiencies were commonly seen after DEX premedication and during CRI. Myocardial radial and longitudinal systolic functions were not affected by sedation or by anesthesia. The late phase of diastole on both right and left ventricles was affected by isoflurane-DEX CRI. Global left ventricular myocardial performance was not impaired. CONCLUSIONS: and clinical relevance Decreased CO and late diastolic impairment were observed in healthy cats administered a low dose of DEX for premedication followed by anesthesia with isoflurane and DEX CRI.

Alterações hematológicas e bioquímicas causadas por Anaplasma marginale em bovinos com aptidão leiteira da região Sudoeste do Paraná / Changes hematological and biochemical caused by Anaplasma marginale in dairy cattle suitability of southwest region Paraná

O objetivo deste trabalho foi descrever as complicações hematológicas e bioquímicas em bovinos da região Sudoeste do Paraná infectados por Anaplasma marginale, comparando estas alterações com os parâmetros apresentados por bovinos sadios da mesma região. Foram avaliadas 40 vacas com aptidão leiteira, sendo 20 clinicamente suspeitas de estarem infectadas pelo parasito e outras 20 sadias, que serviram como grupo controle. O hemograma foi realizado em contador hematológico automático. Para a contagem diferencial de células brancas e pesquisa do agente realizou-se esfregaço sanguíneo. As análises de albumina, proteínas totais (PT), uréria, creatinina, aspartato-aminotrasferase, e gama-glutamiltransferase séricas, foram realizadas em analisador bioquímico semi-automático. Os resultados obtidos foram avaliados através do programa SPSS, versão 20.0, sendo submetidos ao Teste t de Student. O diagnóstico foi realizado pela identificação do hemoparasito em esfregaço sanguíneo. Os animais infectados apresentaram uma parasitemia que variou de 11 a 20%. Constatou-se diferença estatística significante (p<0,01), entre os seguintes parâmetros: hematócrito das infectadas (17,99±1,49%) e sadias (29,38±0,96); número de hemácias das infectadas (3,71±0,39x106 /µL) e sadias (7,23±0,37x106 /µL); hemoglobina das infectadas (6,08±0,65g/dL) e sadias (9,96±0,33g/dL); VCM das infectadas (52,60±3,07fL) e sadias (41,34±1,31fL); monócitos das infectadas (1353,27±373,61/µL) e sadias (517,84±113,22/µL); PT (proteínas totais) das infectadas (7,60±0,18g/dL) e sadias (5,90±0,28g/dL). Os animais infectados apresentaram acentuada anemia e aumento sérico das PT. Conclui-se que estes hemoparasitos provocam monocitose e sinais clínicos graves decorrentes da anemia acentuada, porém não alteram os marcadores da função hepática e renal de bovinos na forma clínica de Anaplasmose.

The objective of this study was to describe the hematological and biochemical complications in cattle of southwestern Paraná region infected with Anaplasma, comparing these changes with the parameters presented by healthy cattle from the same region. We evaluated 40 cows with milk aptitude, 20 clinically suspected of being infected by the parasite and other 20 healthy, which served as a control group. Blood counts were performed in automated hematology counter. For the differential white cell count and agent search was held smears. Albumin analysis, total protein (TP), urea, creatinine, aspartate-aminotransferase and serum gamma-glutamyl transferase were carried out in semi-automatic biochemical analyzer. The results were evaluated using SPSS, version 20.0, and submitted to the Student t test. The diagnosis was made by identifying the hemoparasite in blood smears. Infected mice had a parasitemia ranging from 11 to 20%. We found statistically significant differences (p<0.01) among the following: hematocrit of infected (17,99±1,49%) and healthy controls (29,38±0,96%); number of red blood cells infected (3,71±0,39x106 / µL) and healthy controls (7,23±0,37x106 /µL); of infected hemoglobin (6,08±0,65g/dL) and healthy controls (9,96±0,33g/dL); VCM infected (52,60±3,07fL) and healthy controls (41,34±1,31fL); of infected monocytes (1353,27±373,61/µL) and healthy controls (517,84±113,22/µL); PT (total protein) of infected (7,60±0,18g/dL) and healthy controls (5,90±0,28g/dL). Infected animals showed marked anemia and serum increase in PT. We conclude that these blood parasites cause monocytosis and severe clinical signs resulting from severe anemia, but do not alter markers of liver and renal function of cattle in the clinical form of Anaplasmosis.

Pythiosis in sheep from Paraná, southern Brazil / Pitiose em ovinos no Paraná, Sul do Brasil

This paper reports pythiosis in a sheep from southwestern Paraná, Brazil, confirmed by indirect ELISA (Enzime-Linked Immunosorbent Assay) and immunohistochemistry, as well as it describes the macro and microscopic injuries, in order to understand the pathogenicity. A 4-year-old ewe from a flock of 30 Santa Inês sheep, raised semi-extensively with access to a weir, showed cachexia, bilateral enlargement in nasal region, a serous and bloody secretion with a fetid odor from its nose and swollen submandibular and retropharyngeal lymph nodes. Blood collection was performed trough jugular vein puncture in order to make complete blood cell count (CBC) and to obtain serum for the subsequent serological examination...

Este trabalho tem como objetivo descrever um caso de pitiose confirmado por ELISA (Enzime-Linked Immunosorbent Assay) indireto e imuno-histoquímica em uma ovelha do sudoeste do Paraná, Brasil, bem como suas lesões macro e microscópicas, a fim de compreender a sua patogenicidade. Trata-se de um ovino, fêmea, de 4 anos de idade, de um rebanho de 30 animais, da raça Santa Inês, criados em sistema semiextensivo, com acesso à um açude. O animal vinha apresentando aumento de volume na região do focinho, associado a emagrecimento progressivo. No exame físico apresentou-se caquético, com aumento de volume bilateral na região nasal, e com uma secreção serosanguinolenta de odor fétido fluindo das narinas, além de possuir os linfonodos submandibulares e retrofaríngeos bilateralmente infartados. Foi realizada coleta de sangue por punção da veia jugular para realização do hemograma e obtenção do soro para posterior realização de exame sorológico....