Camila Serina Lasta

Hematological, biochemical and ruminant parameters for diagnosis of left displacement of the abomasum in dairy cows from Southern Brazil

O objetivo deste trabalho foi avaliar indicadores hematologicos, bioquimicos e ruminais no diagnostico e tratamento do deslocamento de abomaso a esquerda (DAE) em vacas leiteiras, na Regiao do Planalto do Rio Grande do Sul, Brasil. Foram coletadas amostras de liquido ruminal, sangue e urina de 40 animais, dos quais 20 vacas com DAE e 20 vacas clinicamente sadias utilizadas como grupo controle. Os animais com DAE, quando comparados ao grupo controle, apresentaram diminuicao da producao de leite diaria, do peso corporal e do escore condicao corporal. A utilizacao de fitas reagentes para medicao do pH ruminal demonstrou-se eficaz em campo, em comparacao ao potenciometro digital. A dinâmica ruminal apresentou-se prejudicada nos animais com DAE, o que foi evidenciado pelos valores aumentados do tempo de reducao de azul de metileno. Os valores sericos de lactato, beta-hidroxibutirato, ureia, albumina, acidos graxos livres e colesterol apresentam-se como ferramentas auxiliares na caracterizacao da doenca.

Molecular detection of Ehrlichia canis and Anaplasma platys in dogs in Southern Brazil

The aims of this study were to determine the occurrence of Anaplasma platys and Ehrlichia canis infection in dogs in Porto Alegre, Southern Brazil; and to investigate their association with hematological abnormalities. Serum samples from 196 dogs were first tested using dot-ELISA for antibodies against Anaplasma spp. and Ehrlichia canis. Peripheral blood samples from 199 dogs were subjected to 16S rRNA nested PCR (nPCR) for A. platys and E. canis, followed by DNA sequencing to ensure pathogen identity. A total of 19/196 samples (9.69%) were positive for Anaplasma spp. using ELISA and 28/199 (14.07%) samples were positive for A. platys by nested PCR. All the dog samples were negative for E. canis, both in anti-E. canis antibody tests and in nested PCR. There were no significant differences in hematological parameters between A. platys-PCR positive and negative dogs and Anaplasma spp. serologically positive dogs, except for basophil counts, which were higher in nPCR-positive dogs. This is the first report showing A. platys presence in dogs in Southern Brazil. In conclusion, hematological parameters may not be sufficient to diagnose A. platys infection in dogs in Southern Brazil, probably due either to low pathogenicity or to chronic infection. On the other hand, E. canis may either have very low occurrence or be absent in dogs in Porto Alegre.

Infecção por Hepatozoon canis em canino doméstico na região Sul do Brasil confirmada por técnicas moleculares

Canine Hepatozoonosis is a vector-borne disease caused by the protozoa Hepatozoon spp. There are few case reports in Brazil and the epidemiology, pathogenicity, vectors and molecular characterization is poorly understood. The present study used a canine presenting weight loss, regenerative anemia, neutropenia and hyperglobulinemia. Hepatozoon spp. gamonts were observed in the blood smear by microscopy. DNA was extracted from blood, and the diagnosis was confirmed by PCR assay. The PCR product was purified from gel and cloned. A fragment of 625bp was sequenced and submitted to the GenBank database as Isolate Porto Alegre. Molecular analysis showed a homology of 98-100% with Hepatozoon canis and less than 92% for H. americanum. This study represents the first molecular confirmation that H. canis is present in Southern Brazil.

Frequencies of DEA blood types in a purebred canine blood donor population in Porto Alegre, RS, Brazil

The study of canine immunohematology is very important for veterinary transfusion medicine. The objective of this study was to determine the DEA blood type frequencies in a purebred canine blood donor population from Porto Alegre, RS, Brazil. One hundred clinically healthy purebred dogs were chosen, 20 dogs from each breed (Great Dane, Rottweiler, Golden Retriever, German Shepherd and Argentine Dogo). Blood samples were taken in ACD-A tubes and the MSU hemagglutination tube test (MI, USA) was used to determine the blood types. The studied population presented general frequencies of 61% for DEA 1.1, 22% for DEA 1.2, 7% for DEA 3, 100% for DEA 4, 9% for DEA 5 and 16% for DEA 7. A significant association was found between breeds and certain combinations of blood types in this population. The results are in agreement with the literature since most part of the canine population studied was positive for DEA 1.1, the most antigenic blood type in dogs. Differences were found among the studied breeds and those should be considered when selecting a blood donor. The knowledge of blood types frequencies and their combinations in different canine populations, including different breeds, is important because it shows the particularities of each group, helps to keep a data bank of local frequencies and minimizes the risks of transfusion reactions.

Development of a quantitative PCR for the detection of Rangelia vitalii

The aim of this study was to develop and validate a SYBR Green qPCR assay to detect and quantify a fragment of the 18S rRNA gene of Rangelia vitalii in canine blood. Repeatability of the qPCR was determined by the intra- and inter-assay variations. The qPCR showed efficiency of E=101.30 (r(2)=0.996), detecting as few as one copy of plasmid containing the target DNA. Specificity of the assay was performed using DNA samples of Babesia canis, B. gibsoni, Ehrlichia canis, E. ewingii and Leishmania sp. No cross-reactivity was observed. Field samples consisting of blood from 265 dogs from Porto Alegre, Brazil were also tested. A total of 24 (9.05%) samples were positive for R. vitalii. Amplicons of 50% of positive samples were confirmed to be R. vitalii by Sanger sequencing. The positive samples had an average of 3.5×10(5) organisms/mL of blood (range: 1.27×10(3)-1.88×10(6)) based on the plasmid-generated standard curve. In conclusion, the SYBR Green qPCR assay developed herein is sensitive and specific and can be used as a diagnostic tool for detection and quantification of R. vitalii in canine blood samples.

Comparison of JC-1 and MitoTracker probes for mitochondrial viability assessment in stored canine platelet concentrates: A flow cytometry study: Mitochondrial Viability in Stored Platelets

Mitochondria perform crucial roles in many biochemical processes, and mitochondrial depolarization is an early sign of platelet apoptosis. The mitochondrial membrane potential is usually evaluated through JC‐1 probe, but it can also be assessed with MitoTracker probes. Our aim was to evaluate mitochondrial viability in stored canine platelet concentrates (PCs) with the fluorescent probes JC‐1 and MitoTracker. Platelets from 22 canine PCs were stained with JC‐1 and MitoTracker probes on days 1, 3, and 5 of storage. Data on metabolic parameters were also collected for correlation studies. Results of JC‐1 and MitoTracker revealed a decrease in mitochondrial membrane potential in day 5 of storage compared to days 1 and 3, providing evidence of mitochondrial depolarization, a finding that was confirmed by the data on metabolic parameters. MitoTracker probes also added information regarding platelet swelling. In conclusion, MitoTracker probes offered a more complete mitochondrial analysis in the evaluation of stored canine PCs.