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.

ResumoFoi realizado um estudo retrospectivo dos casos de tristeza parasitária bovina (TPB) em bovinos com até um ano de idade ocorridos na região de Botucatu-SP, área de influência do Hospital Veterinário da Faculdade de Medicina Veterinária e Zootecnia de Botucatu -UNESP, entre os anos de 1986 e 2007. Ocorreram, nesse período, 232 casos da doença e 57 mortes. O principal agente etiológico causador da doença nesta região foi o Anaplasma marginale, identificado como um único agente em 31,5% dos episódios da doença. A maioria dos casos ocorreu no Outono, em animais mestiços e com dois a seis meses de idade. Os sinais clínicos predominantes foram: apatia, hiporexia ou anorexia, desidratação, perda de peso e palidez das mucosas. A elevada incidência e mortalidade observadas justificam ações profiláticas visando o equilíbrio entre hospedeiro, agente, vetor, e meio ambiente, evitando, assim, a forma clínica da doença e morte dos animais em rebanhos da região. Palavras-chave: Tristeza parasitária, hemoparasitas, bovinos AbstractA retrospective study of Cattle Tick Fever was made with animals up to one year old, which occurred from 1986-2007 in Botucatu-SP in the influence area of the Veterinary Hospital of the School of Veterinary Medicine and Animal Science -UNESP. There were 232 cases and 57 deaths. The main etiological agent causing the disease on this region is Anaplasma marginale identified as a single agent in 31.5% of the cases. Most of the cases occurred on autumn in mixed-blood animals two to six months old. Predominant clinical signs included apathy, hyporexia or anorexia, dehydration, weight loss and pale mucosa. The high incidence and mortality observed justify prophylactic actions to have the balance between host, agent, vector, and environment, thus avoiding the clinical form of disease and death of livestock herds in the region.

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.

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.