This study aims to determine the serological profile of high-yielding dairy cows for four main viruses (bovine alphaherpesvirus 1 (BoAHV1), bovine viral diarrhea virus (BVDV), bovine parainfluenza virus 3 (BPIV3), and bovine respiratory syncytial virus (BRSV)) related to bovine respiratory disease (BRD) in cattle herds worldwide. In this survey, 497 blood serum samples were collected from non-vaccinated dairy cows without clinical respiratory signs in 39 herds in the central-eastern mesoregion of Paraná State, South Brazil. The presence of neutralizing antibodies was determined by virus neutralization (VN) tests. VN antibodies against BoAHV1, BVDV, BPIV3, and BRSV were detected in 355 (71.4%), 280 (56.3%), 481 (96.8%), and 315 (63.4%) serum samples, respectively. The frequencies of seropositive herds for BoAHV1, BVDV, BPIV3, and BRSV were 79.5 (n = 31), 82.0 (n = 32), 100 (n = 39), and 84.6% (n = 33), respectively. The frequencies of seropositive cows varied according to the type of herd management and the number of cows in the herd. The detection of VN antibodies in unvaccinated dairy cattle herds demonstrated the endemic circulation of the four viruses in the herds evaluated. For BRD prevention, it is recommended to implement a vaccination program for cows that provides passive immunity in calves and active immunity in cows.

Sheep-associated malignant catarrhal fever (SA-MCF) is a severe lymphoproliferative vascular disease of cattle that is caused by ovine gammaherpesvirus 2 (OvGHV2), which is a Macavirus within the Gammaherpesvirinae subfamily. SA-MCF occurs worldwide in several mammalian hosts. Alternatively, alcelaphine gammaherpesvirus 1 (AlGHV1) is a Macavirus that causes wildebeest-associated malignant catarrhal fever (MCF), which principally occurs in cattle from Africa. Previous serological assays to evaluate the presence of MCF in mammals used a competitive inhibition enzyme-linked immunosorbent assay (CI-ELISA). This CI-ELISA is based on the 15A antigenic epitope that is common to all Macavirus associated with the development of MCF in their respective hosts. This study evaluated an indirect MCF-specific ELISA assay based on the AlGHV1 C500 strain to detect antibodies against OvGHV2 in 43 closed dairy cattle farms from Southern Brazil. These farms are located in a region where subclinical infections by OvGHV2 have been detected in free-ranging wild boars (Sus scrofa). Sheep or goats were not reared at these farms or within the proximity of these farms. Risk factors associated with seropositivity to OvGHV2 were evaluated, while the possible participation of subclinically infected wild boars in the dissemination of OvGHV2 was estimated using spatial analysis. Sera from 29 dairy cows from 16 farms demonstrated sample/positive (S/P) values considered positive with this MCF-specific ELISA (cutoff S/P, 0.063). The S/P values for the positive dairy cows varied between 0.0633 and 0.2510 (mean, 0.0998; standard deviation, 0.0476). At least one cow was seropositive in 16/43 (37.2%) of these farms, with seropositivity identified in 29/367 (7.9%) of dairy cows maintained at these farms. Additionally, dairy cows raised within the intensive system had a more than threefold higher chance of being seropositive to OvGHV2 relative to those reared within the semi-intensive system. Furthermore, the spatial evaluation revealed that cows on dairy farms within a 50 km radius of the home range of subclinically infected wild boars had an increased risk of being seropositive to this assay. These findings demonstrated that the AlGHV1 C500-specific MCF ELISA can be efficiently used to monitor the occurrence of OvGHV2 in cattle. In addition, the occurrence of subclinically infected free-ranging wild boars within a radius of 50 km from susceptible cattle may be a possible risk factor for the occurrence of OvGHV2-related infections in these animals from Southern Brazil. These initial results are fundamental to understanding the epidemiology of OvGHV2-associated infections and clinical SA-MCF in mammals in Brazil.

Este trabalho objetivou estudar os efeitos de quatro soluções eletrolíticas orais (SEO) comerciais, de uma SEO não comercial (SEO UEL) e da solução de ringer com lactato (SRL), sobre a glicemia e os equilíbrios hídrico, eletrolítico e ácido-base de bezerros neonatos sadios. Utilizaram-se seis bezerros, os quais receberam todas as seis SEO, uma por vez, e cada tratamento foi realizado no período de um dia. Amostras de sangue venoso foram coletadas, em diferentes momentos do dia de tratamento, para a determinação da proteína plasmática total, glicemia e hemogasometria. Valores de SID₃ e variação do volume plasmático foram calculados. A análise de variância de medidas repetidas foi empregada para comparação entre os momentos e as soluções. As SEO não provocaram alterações de magnitude alta ou prolongadas nos equilíbrios hídrico, eletrolítico e ácido-base dos bezerros. Pode-se concluir que todas as SEO, à exceção da SEO A, originaram expansão da volemia. As SEO B e C originaram efeito alcalinizante, enquanto a D afetou a glicemia, e a SRL aumentou a cloremia. A SEO UEL não produziu nenhum efeito marcante além da expansão do volume plasmático.

A urolitíase é uma doença importante de cordeiros confinados. A acidificação da urina, pela ingestão de cloreto de amônio, é o método preventivo mais frequentemente empregado. Devido à falta de informação específica em ovinos, este estudo foi realizado para avaliar as alterações que ocorrem nos eletrólitos urinários de cordeiros, que receberam cloreto de amônio na dieta. Foram utilizados 100 cordeiros, com 3 meses de idade, que foram mantidos em confinamento durante 56 dias, e distribuídos em 3 grupos: G1 (n=40) que receberam 400mg/kg de peso vivo (PV) de cloreto de amônio/dia, durante 21 dias; G2 (n=40) que receberam 400mg/kg de PV de cloreto de amônio/dia durante 42 dias; e G3 (n=20) que não receberam cloreto de amônio. Os cordeiros foram examinados e as amostras de sangue e urina foram colhidas a cada 7 dias: 0 (antes do início da ingestão de cloreto de amônio), 7, 14, 21, 28, 35, e 42 dias. As concentrações séricas e urinárias de sódio (Na⁺), potássio (K⁺), cloreto (Cl^-), e de creatinina foram mensuradas em todos os momentos de colheita. A excreção fracionada urinária (EFu) de eletrólitos e a diferença de íons fortes (SID) na urina [(Na⁺ + K⁺) - Cl] foram calculadas. A EFu de Na⁺, K⁺ e Cl^- não variou ao longo do tempo em G3, provando que a dieta de confinamento, por si só, não influenciou a excreção urinária destes eletrólitos. A ingestão de cloreto de amônio, pelo grupo G1 e G2, influenciou a EFu sobre o tempo de confinamento. A SID urinária foi mais precisa do que a EFu de Cl^- para demonstrar que a concentração de Cl^- aumentou na urina, o que destacou a relevância desta variável.

The effects of a new intravenous electrolyte solution for veterinary therapy on electrolyte and acid-base balances of horses were evaluated, assessing the potential of the use of this solution as a rational alternative in fluid therapy. Eight healthy adult horses, including 4 males and 4 females, received two treatments in a cross-over design: isotonic saline solution (IS) and a test solution (TS) containing 145mEq of Na+, 5mEq of K+, 4mEq of Ca++, 2mEq of Mg++, 96mEq of Cl-, 60mEq of lactate, 50g of dextrose, and 4mg of cyanocobalamin per liter. Solutions were IV infused in a volume corresponding to 5% of BW, over 3 hours. Venous blood samples were taken 5 times before and after the infusion (at 0, 3, 6, 9 e 24h), for pHv, pCO2v, HCO3 -v, BEv, Na+, K+, Cl-, Ca++, Ca, P, Mg, glucose and L-lactate measurements, and AG and SID calculations. The data were analyzed through repeated measures ANOVA. The IS caused mild acidifying effect by increasing Cl- and decreasing plasma SID. In contrast, the TS induced mild and transient hypochloremia without changes in acid-base balance. Hyperglycemia was present at the end of the TS infusion and reversed 6 hours later. The horses did not exhibit any clinical changes. We concluded that TS is an option for fluid therapy in horses.