Pesq. Vet. Bras. 34(8) The incidence of obstructive urolithiasis in sheep is high, especially in feedlot males, both for meat production, or the breeder of high genetic value. The urinary acidification is one way to prevent this disease and can be performed effectively supplementation with ammonium chloride in the diet, which may facilitate the installation of metabolic acidosis. The blood gas analysis evaluates the acid-base balance of blood in a practical and easy way. In this study, it was evaluated the effect of ammonium chloride on acid-base and electrolyte in feedlot sheep blood gas analysis to determine the occurrence of metabolic acidosis. It was used 100 male lambs, in a feedlot, aged approximately three months. It was constituted three groups: Group I (n=40) that received 400mg/kg/PV of ammonium chloride/animal/ day for 21 consecutive days, the time of discontinuation of the urinary acidifiers (M3) and continued clinical follow until the end of the experiment (M6); Group II (n=40), that received 400mg/kg/PV of ammonium chloride/animal/day for 42 consecutive days, Group III (n=20), that did not receive ammonium chloride throughout the experimental period. The moments (M) of samples and clinical assessment were established on seven days of interval, M0 (immediately before the beginning of the treatment with ammonium chloride), M1 (seven days after), M2, M3, M4, M5 and M6, totalizing 56 days of feedlot. The feed consisted of a total mixed ration consisting of 15% of ground hay and 85 % of concentrate, water and mineral salt ad libitum. After 15 days of adaptation to the diet of feedlot, urine samples for measurement of pH, and venous blood for blood gas analysis were collected from all animals at different moments. The urinary acidification was maintained as was the administration of ammonium chloride in GI and GII. The values of Na + and K + remained within the normal range for the species. Ammonium chloride caused metabolic acidosis compensated change in GI and GII, confirmed by values of HCO 3 -and EB below the reference values, with a normal pH, and high levels of Cl -, and decreased SID. It was concluded that although ammonium chloride to cause decrease of alkalinity in the body, caused no loss in animal development and can be used as a preventive agent obstructive urolithiasis in sheep.INDEX TERMS: Ammonium chloride, electrolyte balance, acid-base balance, metabolic acidosis, urinary acidifiers, hyperchloremia, small ruminants, urolithiasis.

The cardiovascular system in newborns has unique features; the system differs from that of foetuses due to the onset of pulmonary respiration and the closure of shunts and differs from that of adults due to heart and autonomic system immaturity. Twenty Ile de France lambs were evaluated during the first 35 days of life to describe changes in the electrical conduction of the heart and in the sympathetic and parasympathetic system during the neonatal period. Electrocardiographic evaluation and the sympathovagal balance was assessed by heart rate variability (HRV) were performed, and ambulatory electrocardiography was performed with a Holter system from birth and at 7, 14, 21, 28 and 35 days of age. There was a significant difference in the duration of the PR and QT intervals and the T wave, as well as a decrease in the amplitude of the P, R and T waves for the evaluated moments. The heart rate and total QRS decreased progressively until 35 days, whereas the HRV indexes increased during the same period. The neonatal period requires care and attention, as several adaptations for neonate survival in the extrauterine environment occur during this period.Abbreviations: HRV: heart rate variability; PR, QT: electrocardiographic intervals; P, R and T: electrocardiographic waves; QRS: electrocardiographic complexes; I, II, III, aVL, aVF and aVL: electrocardiographic member derivations; FP: frontal plane of electrocardiogram; HR: heart rate; RR or NN: interval between two R waves in Holter evaluation; NNmed: the average value of all normal cycles measured during the Holter evaluation; RMSSD: square root of the average of successive differences squared between normal RR intervals measured during the Holter evaluation; pNN50: successive differences between the percentage of RR intervals greater than 50 ms in Holter evaluation ARTICLE HISTORY

Resumo: A acidificação urinária com cloreto de amônio (CA) é um método preventivo eficiente em urolitíase obstrutiva em ovinos. Os objetivos deste estudo com ovinos confinados, que receberam dieta concentrada com elevado teor proteico, foram: verificar o efeito da dieta sobre a formação de urólitos e o desenvolvimento da doença; analisar as características macroscópicas e histopatológicas do sistema urinário; relacionar os achados clínicos, laboratoriais e necroscópicos com a presença de urólitos. Utilizaram-se 60 ovinos machos: grupo CA (n=40), 400 mg/kg CA/dia, tratados via oral, por 42 dias consecutivos; grupo-controle (n=20), não tratado. Determinaram-se sete momentos de colheita de amostras com intervalos de sete dias, no total de 56 dias de confinamento. Encontraram-se microcálculos na pelve renal em cinco animais de ambos os grupos. As lesões renais microscópicas mais relevantes foram congestão vascular e necrose tubular. Concluiu-se que a dieta rica em concentrado provocou lesão renal em ambos os grupos, embora sem alterar a função renal, o que foi comprovado em testes pela ureia e creatinina séricas. O cloreto de amônio fornecido ao grupo CA não impediu a calculogênese, mas reduziu sua prevalência em relação ao grupo-controle. Os ovinos do grupo-controle tiveram maior comprometimento renal, pela alta incidência de cristalúria e pela necrose tubular, induzidas pelo consumo da dieta rica em grãos.

There are studies on electrocardiogram (ECG) in several breeds of horses, which highlights the growing importance of cardiology in this species. But few authors have addressed the influence of pregnancy on the cardiac physiology of the mare, and specifically, there are no studies on the Mini-horse breed, as well as no correlation of body weight (BW) and heart rate (HR) with electrocardiographic parameters in this breed. The aims of this study were to determine the effects of pregnancy on ECG parameters and to examine the relationships between these variables and body weight (BW) and heart rate (HR). A total of 203 animals were used, including 143 females (66 pregnant) and 60 males. Electrocardiographic examinations were performed by computerized electrocardiogram (TEB), and the parameters were evaluated in six leads in the frontal plane (Lead I, II, III, aVR, aVL and aVF) and base-apex (BA). BW was inversely proportional to HR, which in turn showed an inverse relationship with the duration of the P-wave and the PR and QT intervals. The P-wave amplitude (lead II) was higher in pregnant animals than in non-pregnant animals. The effect of reproductive status should be monitored by ECG throughout the entire gestational period. The 66 pregnant mares in this study were examined during the first third of their pregnancies, thus, few differences were observed between pregnant and non-pregnant animals.Keywords: horse, body weight, cardiology, heart rate, pregnancy RESUMO Existem estudos sobre eletrocardiograma (ECG) em diversas raças de equinos

The hematopoietic system changes during the pregnancy to carry fetal development and maternal needs. This study compared the hematological parameters between ewes with single and twin pregnancies during gestation, delivery, and postpartum. The experiment was conducted on 60 healthy pregnant Dorper ewes that were divided into two experimental groups: Group 1 (G1), with single pregnancies (n=30), and Group 2 (G2), with twin pregnancies (n=30). Blood samples were collected from all ewes at different times: immediately before fixed-time artificial insemination (AI); on day 30, 90, 120, 130, and 140 of pregnancy; immediately after delivery; and at 24h and 48h postpartum. Statistical analysis compared the two groups at different times (P<0.05). Mild, normocytic, and hypochromic anemia was detected in all ewes from AI time and throughout pregnancy from both groups, but did not prove to be of clinical relevance. In the peripartum stage (from the 140th day of pregnancy to 48h postpartum), the ewes with twin pregnancies (G2) exhibited higher erythrogram values and neutrophil:lymphocyte ratio than did ewes with single pregnancies (G1). This indicated a greater hematopoietic adaptation in the body during the development of two fetuses. Except for the eosinophil numbers, all leukogram parameters were influenced by pregnancy in a similar way in both groups, and was characterized mainly by leukocytosis with neutrophilia during peripartum due to the high presence of endogenous cortisol at delivery. Thus, these findings showed that pregnancy was a stressful physiological event that increased the leukocyte count with a slight alteration in the erythrogram of Dorper ewes.

RESUMO.-[Parâmetros eletrocardiográficos de equinos Mini Horse: influência da idade e sexo.]A cardiologia veterinária possui crescente importância na medicina equina. Existem estudos de padronização dos parâmetros eletrocardiográficos de muitas raças, de acordo com sua estatura e aptidão. No entanto, não há na literatura trabalhos com os equinos da raça Miniature Horse. Os objetivos deste trabalho foram avaliar a configuração do traçado do eletrocardiograma (ECG) em repouso, de equinos desta raça, além de verificar a influência do sexo e da idade sobre os parâmetros eletrocardiográficos desses animais. Foram utilizados 203 equinos desta raça, hígidos, sendo 143 fê-meas e 60 machos, classificados em quatro faixas etárias (potros, sobreanos, adultos e idosos). Os exames eletrocardiográficos foram realizados por eletrocardiograma computadorizado (TEB), e os parâmetros foram avaliados em seis derivações do plano frontal (DI, DII, DIII, aVR, aVL e aVF) e base-ápice (BA). A frequência cardíaca (FC) diminuiu com a progressão da idade, e foi maior nos machos do que nas fêmeas. O ritmo mais comum em ambos os se- The veterinary cardiology has growing importance in equine medicine. There are studies of standardization of electrocardiographic parameters of many races, according to their stature and ability. However, no studies are in the literature with the American Miniature Horse. To evaluate the electrocardiogram (ECG) tracing configuration of this breed at rest and to verify the influence of age and sex on ECG parameters, 203 horses including 143 females and 60 males were divided into four age groups (foals, yearlings, adults and elderly). Electrocardiographic parameters were performed by computerized electrocardiogram (TEB), and the parameters were evaluated in six leads of frontal plane (Lead I, II, III, aVR, aVL and aVF) and base-apex (BA). Heart rates (HR) decreased with increasing age were higher in males than in females. Sinus tachycardia followed by sinus arrhythmia was dominant in both sexes. The cardiac axis was higher in males and ranged between 120° and 150° for foals, 30° and 60° for yearlings and adults, and 60° and 90° for the elderly. The P wave was bifid in several animals. The P-wave amplitude and T-wave duration from lead II and BA were larger in males than in females. The majority of the animals exhibited ST segment depression and a negative T-wave. The most common QRS complex morphology was Qr. Differences were observed between the electrocardiographic tracings of males and females, and age influenced the ECG parameters. Therefore, this study established the ECG patterns for the American Miniature Horse breed and could be used to determine the influence of age and sex on several of the studied variables. . A amplitude da onda P e a duração da onda T foram maiores nos machos do que nas fêmeas na DII e BA. A maioria dos animais apresentou segmento ST infradesnivelado e onda T negativa. A morfologia do complexo QRS mais encontrada em todos os casos foi Qr. Este estudo permitiu estabelecer os padrões ele...

RESUMO Nas ovelhas, a demanda de nutrientes aumenta durante a gestação, especialmente nas últimas seis semanas, quando ocorre maior desenvolvimento do feto. Os objetivos deste trabalho foram estudar o perfil bioquímico de ovelhas durante a gestação e no periparto imediato, comparando-se gestação única com gemelar. Foram utilizadas 60 ovelhas, Dorper, divididas em dois grupos experimentais com base no diagnóstico de gestação ultrassonográfico: grupo 1: 30 ovelhas com feto único; grupo 2: 30 ovelhas com gestação gemelar. Em nove momentos de coleta, foram mensurados no soro sanguíneo: ureia, creatinina, proteína total (PT), albumina, globulina, aspartato aminotransferase (AST), gamaglutamiltransferase, fosfatase alcalina, colesterol e triglicérides. O peso vivo das ovelhas do G2 foi maior que do G1 em todos os momentos, inclusive quando estavam vazias. Houve diferença entre as ovelhas do G1 e do G2 nos valores de PT, albumina, AST e triglicérides. A partir de 120 dias de gestação, o perfil proteico se modificou, com menores níveis de ureia, PT, albumina e globulina, mostrando que a demanda metabólica se intensificou no último mês da gestação. Os níveis de colesterol e triglicérides diminuíram de 140 dias de gestação para o parto. Este trabalho mostrou que a gestação proporcionou mudanças significativas no metabolismo da ovelha, principalmente no terço final da gestação, quando há maior necessidade de acompanhamento para evitar a incidência de doenças metabólicas.

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