Search

Dermacentor nitens Neumann is the most common tick species infesting horses in the main Brazilian biomes. It has a predilection to attach to horse the ears, the nasal diverticulum, perineal and perianal regions. The infestations can generate severe damage in the ears, anemia, and the tick also acts as vector of Babesia caballi (Nuttall and Strickland), the causative agent of equine babesiosis. Our study describes unusual parasitism site of D. nitens on a female cross breed horse, approximately ten years old that presented high parasitism by ticks on the perineal and perianal region, ears, and the left eye orbit region, where an enucleation process had been performed a few years earlier. To our knowledge this is the first report of D. nitens parasitism on a formerly enucleated eye orbit. [ABSTRACT FROM AUTHOR]

Host-parasite interactions between ticks and wild species are important for examining the ecology and distribution of ticks, as well as the consequences of these interactions for hosts and diseases. Ticks have medical importance because they are vectors of microorganisms and pathogens, such as viruses, bacteria, and protozoa, that can be transmitted to humans and other animals, causing serious disease. Like other anuran species, Rhinella marina also harbors a wide variety of parasites. This occurs mainly because of its large body size and because it occupies terrestrial environments, but also because it has direct contact with aquatic environments (larval and reproductive stages), thus presenting several opportunities for parasitic infections. This work has as main objective to describe the occurrences of host-parasite interactions between the species Rhinella marina (Linnaeus, 1758) and Amblyomma rotundatum (Koch, 1844) geographically expanding their occurrence in the Amazon rainforest through the Madeira River. During a herpetofauna survey, the first individual of R. marina was observed at 08:37 PM on September 20, 2020. The location is near a transect within a primary forest. This individual was parasitized by a single tick identified as Amblyomma rotundatum. On a second expedition, a second individual of R. marina was observed at 11:38 PM on January 5, 2021. The location is rural road C-01 in the municipality of Porto Velho-RO, which passes within a primary forest and deforested private properties. This individual was parasitized by nine ticks identified as Amblyomma rotundatum. An important observation to be made is that the occurrences of A. rotundatum parasitizing R. marina are 57 km apart and cross an important geographical barrier, the Madeira River of the Amazon basin. This work geographically expands the occurrence of A. rotundatum parasitism on R. marina and describes the natural histories of this host-parasite interaction of these species. [ABSTRACT FROM AUTHOR]

The objective of the present study was to assess the treatment of dogs with ehrlichiosis (tropical canine pancytopenia (TCP)) with doxycycline hydrochloride associated or not with prednisolone on the hematological profile and serum proteins. Ten dogs with TCP were selected in the Small Animal Medical Clinic Veterinary Hospital, Federal University of Campina Grande-UFCG-PB, Brazil. The diagnosis was obtained by clinical examination, hemogram and immunochromatographic test (with anti Ehrlichia canis antibodies). Samples were distributed randomly in two experimental groups of five animals each (n = 5), named GD and GDP. The GD group was treated with doxycycline (5 mg/kg, VO, BID for 28 days) and the GDP group was treated with doxycycline at the same dose and duration and prednisolone (2 mg/kg, VO, BID, for five days). Four blood collections were made during the treatment period: a base collection (M0), one at 10 days (M10), a second at 21 days (M21) and another at the end of the treatment (M28). These samples were used for the tests erythrogram, leucogram, plateletgram and proteinogram (dose of total proteins, pre-albumin, albumin, albumin, α-1 globulin, α-2 globulin, ß-globulin, ɣ-globulin and C-reactive protein) in the Clinical Pathology Laboratory, Veterinary Hospital-UFCG-PB. Results, that presented normal distribution, was submitted to the Tukey test (P<0.05). Comparison of treatments GD and GDP showed that both promoted discreet and similar response in the hematological parameters at different times. Results obtained allowed the conclusion that both therapeutic protocols resulted in clinical, hematological parameter and proteinogram improvement, but the use of prednisolone at the dose administered during the first five days of treatment did not show more beneficial effects than isolated administration of doxycycline. [ABSTRACT FROM AUTHOR]

The aim of this study was to evaluate the in vitro efficacy of the Himatanthus sucuuba hydroalcoholic extracts against larvae and engorged female of Rhipicephalus microplus. The extracts were prepared by percolation from latex, stems and leaves in absolute alcohol and lyophilized. We performed the larval packet test, LPT in serial concentrations (0.4 - 204.8 mg.mL-1) and adult immersion test, AIT (6.4-396.8 mg.mL-1) using six replicates. The complete phytochemical composition was determined to all the extracts. From the LPT and TIA, the latex demonstrated the best results, with an LD50 of 21.4 and 105.2 mg.mL-1, respectively. The phytochemical data, combined with the dose-dependent results obtained from the in vitro tests demonstrates that this extract has potential to control R. microplus. Further studies should be conducted to maximize the effectiveness of the latex portion of the plant. [ABSTRACT FROM AUTHOR]

This experiment was carried out to study the bioacaricidal activity of Amburana cearensis against engorged females of Rhipicephalus (Boophilus) microplus. The crude ethanolic extract from the leaves of A. cearensis was submitted to partition with organic solvents (hexane, chloroform and ethyl acetate) in order of increasing polarity; and evaluated using three treatments at concentrations of 5, 10 and 25mg ml-1. To evaluate the acaricidal activity, engorged females were submitted to the adult immersion test. Parameters analyzed were the weight of females; weight of egg mass; percentage of hatch; reproductive efficiency; expected rate of reproduction; and efficacy. For each extract and concentrating fraction, tests were performed in triplicate. Among all fractions, the hexane (2.5%) achieved the best results in all parameters analyzed: 52.7% of inhibition of oviposition; 39% of hatching rate; 3,271 index of reproductive efficiency; and 67.0% effectiveness. The extract obtained gradual dose response with increasing concentration; and could be used as an aid in the control of R. (B.) microplus therapy. [ABSTRACT FROM AUTHOR]

Parasite infections caused by Rhipicephalus (Boophilus) microplus are responsible for the most of economic losses in producing-cattle countries in tropical and subtropical areas. Indiscriminate uses of chemical acaricides have contributed with the appearance of tick resistance to many drugs available in the marketplace, and it is a serious problem in the tick control. Flowers of Sambucus australis (South America), called "sabugueiro-from-Brazil", are used on infusions or decoctions forms in the folk medicine with diuretic, antipyretic, anti-inflammatory, and laxative purpose, also employed for treating respiratory diseases in human. The main goal of this study was to evaluate in vitro potential of S. australis leaves extracts as an acaricide agent. Ethanol extract at 70% has been dehydrated and a fraction was suspended in 70% ethanol or in distillated water at final concentration of 2% (0.2mg-1). Using the immersion test of engorged females the efficiency results were obtained in 34% and 66% with the leaves extract diluted in water and 70% ethanol, respectively. This study is the first report on acaricidal activity of S. australis against cattle tick. Further studies to determine the active metabolites in different stages of S. australis could aid to identify suitable extracts to be tested in the R. (B.) microplus control. [ABSTRACT FROM AUTHOR]

Studies have shown that ticks are susceptible to infection by entomopathogenic nematodes. These studies indicate different susceptibilities of ticks to infection by these fungi, depending on the tick species, development phase, entomopathogenic nematodes species and strains and the time the ticks are exposed to them. Usually this period ranges from 24 to 72 hours. The aim of this study was to evaluate the infection times in vitro of engorged Rhipicephalus (Boophilus) microplus females by the entomopathogenic nematodes Steinernema glaseri CCA strain, by analysis of the ticks' biological parameters. The results show that a 2-hour exposure time was sufficient for the engorged R. microplus females to be infected by S. glaseri CCA, but that a minimum exposure time of 24 hours was necessary to generate treatment efficacy above 90%. [ABSTRACT FROM AUTHOR]

Studies have shown that ticks are susceptible to infection by entomopathogenic nematodes. These studies indicate different susceptibilities of ticks to infection by these fungi, depending on the tick species, development phase, entomopathogenic nematodes species and Strains and the time the ticks are exposed to them. Usually this period ranges from 24 to 72 hours. The aim of this study was to evaluate the infection times in vitro of engorged Rhipicephalus (Boophilus) microplus females by the entomopathogenic nematodes Steinernema glaseri CCA strain, by analysis of the ticks' biological parameters. The results show that a 2-hour exposure time was sufficient for the engorged R. microplus females to be infected by S. glaseri CCA, but that a minimum exposure time of 24 hours was necessary to generate treatment efficacy above 90%. [ABSTRACT FROM AUTHOR]

Infestation by ticks is responsible for significant economic losses to the cattle industry in several regions, including Rio Grande do Sul (RS) state. Losses may be derived from animal stress, weight loss and skin damage, as well as from costs with treatment. The indiscriminated use of pesticides against these parasites has resulted in high levels of genetic resistance to several drugs, representing a problem for disease control. Thus, the objective of this research was to evaluate the susceptibility of field specimens of Rhipcephalus (Boophilus) microplus to the acaricides used in the control of the parasite. Female ticks obtained from 42 farms in different counties of RS were submitted to the engorgeted female immersion test, to estimate the resistance of the parasite to the drugs. Amitraz in combination with chlorpyriphos was the most efficient drug, acting effectively in ticks from 100% of the tested farms (11/11). Associations of cypermethrin-chlorpyriphos-citronelol were efficient in ticks from 61% of the farms (25/41) and cypermethrin-ethion in 37% (10/27). Cypermethrin alone was efficient in 20,7% (6/29) and Amitraz. one of the most used products, was efficient in ticks from only 14,2% (6/42) of the farms. These results demonstrate that most drugs used in the control of R. B. microplus in the state present low efficacy, as measured by in vitro tests. The low drug efficacy is probably derived from the genetic resistance developed by the parasites due to the indiscriminated and inadequate use of these acaricides in the field. [ABSTRACT FROM AUTHOR]

A Anaplasmose Bovina é uma doença causada por bactérias intra-celulares obrigatórias da espécie Anaplasma marginale, família Anaplasmataceae, ordem Rickettsiales, que causa grande impacto na bovinocultura, sendo transmitidas principalmente por carrapatos e moscas (DUMLER et al., 2001). O objetivo do presente estudo foi pesquisar a presença de A. marginale em gado mestiço holandês de quatro propriedades leiteiras localizadas na região Noroeste do estado de Minas Gerais, Brasil. Foram coletadas amostras de sangue de 40 bovinos oriundos de quatro propriedades localizadas na região Noroeste do estado de Minas Gerais, 13 da propriedade A, 10 da propriedade B, nove da propriedade C e oito da propriedade D. O sangue dos 40 animais foi colhido com auxílio de um sistema à vácuo acoplado a tubo de hematologia contendo EDTA, foram confeccionadas lâminas de esfregaço sanguíneo e as amostras de sangue foram submetidas à extração do material genético com Wizard® Genomic DNA Purification Kit (Promega, Madison, WI, USA) seguindo o protocolo descrito pelo fabricante. Os animais com suspeita clínica tiveram o sangue processado para verificação do hematócrito. As amostras então foram testadas através da técnica de reação em cadeia da polimerase (PCR) para detecção do gene msp5 de A. marginale em uma reação de semi Nested (SINGH et al., 2012). Dos 40 animais analisados, 13 apresentaram resultado positivo para A. marginale, (32,5%). Na propriedade A, dos 13 animais analisados três apresentaram resultado positivo (23,07%), na propriedade B, oito dos 10 animais avaliados foram positivos (80%), quatro dos nove animais analisados da propriedade C positivaram (44,44%) e cinco animais dos oito da propriedade D foram positivos também para A. marginale (62,5%). Todos os proprietários se queixaram da presença de carrapatos ou de moscas dos estábulos (Stomoxys calcitrans) nas instalações onde os animais eram mantidos. Um animal da fazenda A e um animal da fazenda B apresentaram sintomas clássicos de Anaplasmose, como anemia, fraqueza, dificuldade de locomoção, além de possuírem carrapatos em sua superfície corpórea. O animal da fazenda A apresentou eritrócitos com inclusões suspeitas para A. marginale e hematócrito 18%. Os dois animais doentes foram tratados com cloridrato de oxitetraciclina, dipropionato de imidocarb e vitamina B12, sendo que o animal da propriedade B apresentava aumento das frequências cardíaca (150 bpm) e respiratória (64 mpm) e passou por transfusão sanguínea. Um animal da propriedade C estava anêmico, em decúbito lateral e sendo parasitado por moscas, veio a óbito, também apresentou resultado positivo na PCR, mas não foi possível constatar que a morte tenha sido em decorrência da infecção por A. marginale pois a necropsia não foi realizada, mas na microscopia do esfregaço sanguíneo foram visualizadas inclusões marginais nos eritrócitos, também compatíveis com estruturas formadas por A. marginale e o hematócrito era de 19%. [ABSTRACT FROM AUTHOR]

The Rangeliose affects dogs, mainly in southern Brasil. Rangelia vitalli is a protozoan Amblyomma aureolatum and Rhipicephalus sanguineus. The hematological profile of dogs infected with this parasite consistent that of an extravascular hemolytic anemia autoimmune. They may also have anemia, jaundice, fever, splenomegaly, generalized swelling of lymph nodes, persistent bleeding from the nostrils (epistaxis), gastrointestinal bleeding, petechial visible mucous membranes and swelling of the hind limbs. This study aimed to repost the case of a dog, presenting history of anorexia and bleeding on the outside and edge of the ears. On examination of peripheral blood, microorganisms were found compatible with Rangelia vitalli. Clinical treatment was satisfactory, obtaining the patient's improvement. [ABSTRACT FROM AUTHOR]

The aim was to study the occurrence of canine hepatozoonose in rural area municipality of Teresina, Piauí. Were used 384 dogs without distinction of breed, sex and age, from the rural area of Teresina-PI, of which samples were collected for parasitological examination. Of blood smears examined Hepatozoon canis was detected in 0.26% (1/384) of animals. The present study reports the first occurrence of H. canis in dogs from rural areas of Teresina, Piauí. [ABSTRACT FROM AUTHOR]

O carrapato Dermacentor nitens parasita preferencialmente equinos e é popularmente conhecido como carrapato da orelha dos cavalos. A infestação por este parasito promove prejuízos ao animal pela espoliação sanguínea, queda na produtividade, predisposição ao aparecimento de miíases e infecções bacterianas secundárias, além de ser vetor do protozoário Babesia caballi, agente causador da babesiose equina. Assim, o objetivo deste trabalho é avaliar a atividade acaricida in vitro do fipronil, em três diferentes metodologias, contra larvas não alimentadas de D. nitens. Os ensaios foram realizados em duplicata, com larvas não alimentadas de 17 dias, obtidas na colônia do Laboratório de Quimioterapia Experimental em Parasitologia Veterinária (LQEPV) no Instituto de Veterinária (IV) da Universidade Federal Rural do Rio de Janeiro (UFRRJ). As seguintes concentrações de fipronil foram testadas: 1; 2,5; 5; 10; 20; 40; 60; 80 e 100 ppm, obtidas a partir da diluição de fipronil técnico em água e triton-x para as metodologias de imersão larval (LIT) e de LIT adaptado, e em azeite de oliva extra virgem e tricloroetileno (2:1) para a metodologia de pacote de larvas (LPT). Na metodologia LIT, 300 larvas foram imersas em um microtubo com 1mL de solução por 10 minutos. Após drenar a solução, as larvas foram secas e aproximadamente 100 colocadas em envelope de papel filtro (6x6cm). Para LIT adaptado, aproximadamente 100 larvas foram depositadas em um sanduíche de papel filtro (2x2cm) impregnado com 500 µL da solução. Cada sanduíche foi acondicionado em envelope de papel filtro (6x6cm). E para LPT, o papel filtro (8,5x7,5cm) foi previamente impregnado com 670 µL de solução. Após duas horas de secagem, foram feitos envelopes e cerca de 100 larvas foram alocadas em cada. Para as três metodologias, o armazenamento foi feito em estufa climatizada com demanda controlada de oxigênio a 27°C e 80% UR. Após 24 horas foi realizada leitura para avaliação da mortalidade, de acordo com a seguinte fórmula: % de mortalidade = total de larvas mortas x 100 / total de larvas. Os dados encontrados foram tabulados e os valores das concentrações letais CL50 e CL90 foram calculadas estatisticamente por meio da análise Probit utilizando o programa computacional R versão 3.6.1. Para LIT, a CL50 foi de 3,04 ppm (2,36-3,77 ppm), e a CL90 de 22,29 ppm (17,94-28,77 ppm). O slope obtido foi de 1,481±0,334 e o R de 0,584. Enquanto LIT adaptado, a CL50 foi de 14,32 ppm (12,79-15,98 ppm), e a CL90 de 49,19 ppm (42,48-58,30 ppm), e em LPT a CL50 foi de 20,77 ppm (18,50-23,33 ppm), e a CL90 de 80,06 ppm (67,63-97,58 ppm), maiores que as obtidas em LIT. O slope obtido foi de 2,391±0,130 e o R de 0,899 para LIT adaptado, e para LPT o slope foi de 2,187±0,418 e o R de 0,973. Portanto, o fipronil demonstrou ação larvicida in vitro contra D. nitens nas concentrações avaliadas, tornando este fenilpirazol um provável ativo utilizado para o controle deste carrapato, além de LIT ter sido a metodologia mais sensível em que se obteve as menores CLs para o fipronil. [ABSTRACT FROM AUTHOR]