Roberta Carneiro Da Fontoura Pereira

Neosporose equina: ocorrência de anticorpos anti-Neospora spp. e associação entre status sorológico de éguas e de suas crias

Neospora caninum and N. hughesi are protozoa which can infect horses and can cause reproductive and neurological diseases, respectively. The pathogenesis of neosporosis in horses is poorly understood, as well as the sources of horizontal infection of N. hughesi. Furthermore, there are doubts about the role of the vertical transmission of Neospora spp. in maintenance of these parasites in equine populations. In this study, we evaluated: (1) the occurrence of infections by Neospora spp. in a population of mares (in reproductive age) on a farm of Crioula breed horses; and (2) the possible association between the serological status of mares and of their offspring, aiming to investigate, indirectly, the relevance of transplacental transmission for the occurrence of Neospora spp. in these horses. We found a highly significant association between the serological status of mares and their offspring. Although had been exposed to the same environmental risk factors, the descendants of seropositive mares had a higher percentage of seropositivity against Neospora spp. compared to the descendants of seronegative mares. The association between kinship and serological status indicates an influence of vertical (transplacental) infection raising the occurrence of Neospora spp. in the studied equine population.

Comparative performance of macrocyclic lactones against large strongyles in horses

Several formulations of macrocyclic lactones (abamectin, ivermectin, moxidectin), including ivermectin combined with pyrantel (tetrahydropyrimidine) and ivermectin combined with praziquantel (pyrazinoisoquinolin derivative), were tested regarding their efficacy to control gastrointestinal nematodes of horses on a stud farm in southern Brazil. In addition, we tested a pharmaceutically produced generic paste containing ivermectin 4%. Similar formulations of avermectins had different efficacies measured by reduction of EPG. Levels of efficacy of the tested drugs varied against Strongylus edentatus, S. equinus and S. vulgaris. The generic paste (ivermectin 4%) was less effective than the conventional drugs.

Occurrence of antibodies anti-Neospora spp. in cart horses and Crioula breed horses from Rio Grande do Sul state

O objetivo deste estudo foi avaliar a frequencia de deteccao de anticorpos contra Neospora spp. em cavalos de carroca e em cavalos da raca Crioula. Para tal, 214 amostras de soro foram coletadas e analisadas pela tecnica de imunofluorescencia indireta, das quais 91 eram de cavalos de carroca e 123 de cavalos da raca Crioula, todas provenientes da regiao central do Rio Grande do Sul. As frequencias de anticorpos detectadas foram: 15,9% (34/214) na populacao total estudada, 15,4% (14/91) nos cavalos de carroca e 16,3% (20/123) nos cavalos da raca Crioula. Estes resultados sugerem que a infeccao por Neospora spp. esta presente igualmente nas duas populac oes. Assim, devido a importância e ao padrao da patogenese da neosporose em equinos, Neospora spp. deve ser incluido no diagnostico de problemas reprodutivos em eguas e em casos de problemas neurologicos em equinos.

Avaliação de sete protocolos para obtenção de plasma rico em plaquetas na espécie equina

PRP is plasma that contains a high numbers of platelets and growth factors in a small volume. The aim of this study was to evaluate seven different protocols to obtain PRP by the manual method according to their capacity to concentrate platelets, leukocyte and erythrocyte contamination and correlation between platelet count and TGF-β1 growth factor levels in PRP samples. Ten healthy horses with a mean age of 7 years (±2.39), weighing on average 500 kg (±67.1) were used in this study. The protocols tested varied according to the speed and time used at the two centrifugations. PRP samples were analyzed regarding platelet concentration, leukocyte and erythrocyte contamination and TGF-β1 levels quantified by ELISA. No significant differences among protocols were observed regarding the ability to concentrate platelets and TGF-β1. However, protocol I showed significantly higher erythrocyte and leukocyte counts in PRP samples than the other protocols, reason why it was considered inadequate for the volume of blood processed in this experiment. The remaining protocols are suitable for extracting PRP.

Laminite crônica em equídeos da raça Crioula: características clínicas e radiográficas

This study aimed to analyze the clinical and radiographic profile of Criollo horses affected by chronic laminitis brought to the Equine Clinic between 2010 and 2011. Medical records, daily clinical evaluations and radiographic studies were analyzed. Data of nine horses, 55.6% (5/9) females and 44.4% (4/9) intact males with a mean age 8.6±5.9 years and 104.2±91.7 days of hospitalization were included. Laminitis occurred on all four limbs on 22.2% (2/9), while 77.8% (7/9) occurred only on the forelimbs. One out of nine cases laminites was due to endotoxemia (11.1%), 44.4% (4/9) was related to equine metabolic syndrome and on 44.4% (4/9) the cause could not be determined. Sinking of third phalanx ≥20mm identified on radiographic studies occurred on 66.7% (6/9) horses. Only 11.1% (1/9) of the animals presented unilateral sinking of the third phalanx. Sinking of the third phalanx was not correlated with the degree of lameness. Rotation of the distal phalanx (≥5.5°) on at least one member was observed in 66.7% (6/9). There was a positive correlation of the third phalanx rotation degree and the lameness degree (0.1≤r<0.5; P<0.05). Two patients (22.2%) required tenotomy of the deep digital flexor tendon. Insulin resistance was the predisposing cause laminitis most common in this study. Supportive therapy, intensive nursing care, corrective trimming and shoeing provided a high survival rate after discharge so that the animals could be kept comfortable without pain medication.

Cortisol, resposta glicêmica e secreção de insulina em equinos clinicamente sadios submetidos a sessões de hipóxia normobárica

The cortisol levels, glycemic response and insulin secretion were evaluated in non-exercised horses submitted to sessions of normobaric hypoxia. Healthy adult horses (n=8) were selected after physical examination and underwent an intravenous glucose tolerance test (0.5g kg-1) (IVGTT). Blood samples (n=11) were collected between 0 and 180 minutes after glucose administration to evaluate glycemic response and insulin secretion. Then, they were exposed to 1-hour hypoxia sessions twice a day, reaching a total of 43 hypoxia sessions, with [O2] decreasing from 17 to 12%. Heart rate and serum samples to measure cortisol were collected before and every 15 minutes during the sessions 1, 4, 6, 8, 10, 14, 22 and 43. The IVGTT was repeated at the end of the study. The serum cortisol levels were higher in session 1 (S1) (17% O2) when compared to the levels of S10 (13% O2) and S43 (12% O2) (P<0.05). The glycemic curve in resting healthy horses is not altered by exposure to 43 normobaric hypoxia sessions. The increase in insulin secretion, followed by decreased heart rate and serum cortisol suggest an adaptation of the horses to the hypoxia model used.