Ultrastructural characterization and quantification of hemocytes in engorged female Amblyomma sculptum ticks

Amblyomma sculptum (formerly Amblyomma cajennense) ticks have been implicated in the transmission of pathogens that cause diseases in animals and humans. Their wide geographic distribution and high impact on animal health and zoonotic disease transmission highlight the importance of studying and implementing effective control measures to mitigate the risks associated with this tick species. The aim of this study was to quantify and characterize the morphology and the ultrastructure of different types of hemocytes in the hemolymph in engorged A. sculptum females fed on rabbits. The hemolymph samples were collected by perforation of the cuticle in the dorsal region. Hemocyte types, sizes, and differential counts were determined using light microscopy, while ultrastructural analysis of hemocytes was performed using transmission electron microscopy. The average number of total hemocytes in the hemolymph was 1024 ± 597.6 cells µL-1. Five morphologically distinct cell types were identified in A. sculptum females: prohemocytes (6 % ± 8.8), plasmatocytes (10 % ± 7.7), granulocytes (78 % ± 12.2), spherulocytes (5 % ± 4.48), and oenocytoids (1 % ± 1.6). In general, prohemocytes were the smallest hemocytes. The ultrastructural morphology of A. sculptum hemocytes described in the present study agrees with the findings for other hard ticks. This is the first study to investigate ultrastructural characteristics of hemocytes of female A. sculptum ticks.

Environmental enrichment interaction for laboratory beagle dogs used in research

Experimental animal facilities can have a negative impact on the well-being of animals owing to confinement. To mitigate this, environmental enrichment (EE) is implemented confinement. The purpose of EE is to enhance the complexity of an animal's natural environment. The objective of this study was to identify the types of EE most enjoyed by dogs used in experimental research and housed in individual kennels. A total of six adult Beagle dogs, housed at the Laboratório de Quimioterapia Experimental em Parasitologia Veterinária (LQEPV) at the Universidade Federal Rural do Rio de Janeiro (UFRRJ) were included in the study. The EE tools used included Petball® toys, a grassy outdoor area, interaction with other dogs and with a team member, a "pool" made of plastic bottles, and dog's wet food ice cream. A team member assessed the usage of these tools every 5 min for a 30-min period, six times per day, one day per week, over the course of eight weeks. The study revealed that the grass area was the tool most commonly used for physical enrichment, accounting for 58% of the occurrences (p < 0.05). Social and food enrichment were enjoyed in second and third place, with 23% and 19% of occurrences, respectively. that the study findings suggest that dogs housed in individual kennels enjoy engaging in their natural behaviors.

In vitro evaluation of the activity of Cinnamaldehyde as an inhibitor of the biological cycle of Ctenocephalides felis felis

The objective of this work was to evaluate the in vitro activity of cinnamaldehyde as an inhibitor of the biological cycle of Ctenocephalides felis felis. Tests were carried out with six repetitions containing 10 eggs of C. felis felis together with 0.5g of diet and filter paper discs with area of 23.76 cm2 impregnated with different concentrations of cinnamaldehyde (6; 8; 10; 12; 14; 16; 18; 20; 24 and 28 µg.cm-2) in Petri dishes and incubated in a climate-controlled chamber at 27 ± 1 °C and RH 75 ± 10%, for 30 days. The tests included a placebo group containing the diluent (acetone) and a negative control group, without treatment. At the end of 30 days, the percentage of inhibition of adult emergence/mortality was calculated, as well as the LC50 and LC90. Inhibition of adult emergence greater than 50% was observed from a concentration of 10 µg.cm-2 and 100% inhibition from a concentration of 14 µg.cm-2, obtaining LC50 and LC90 results of 8.75 and 13.57 µg.cm-2, respectively. We concluded that the volatile compound cinnamaldehyde is effective in vitro as an inhibitor of the biological cycle of C. felis felis.

Do combinations of fipronil, eugenol and carvacrol have synergistic effects against Rhipicephalus sanguineus?

The tick Rhipicephalus sanguineus is one of the main ectoparasites that affects dogs, causing direct and indirect damage to parasitized animals. Currently, infestation control is mainly carried out by using synthetic acaricidal drugs. However, a decrease in efficacy and an increase in resistance to the main therapeutic protocols against tick infestations have been increasingly reported and confirmed, a factor that has driven research into the potential acaricide activity of natural compounds, including in association with synthetic molecules. The aim of this work was to evaluate whether the combinations of fipronil (FIP) and eugenol (EUG), FIP and carvacrol (CAR), and EUG and CAR would have synergistic effects against immature and unfed adult stages of R. sanguineus through in vitro bioassays. Bioassays were carried out using the larval packet test (FAO 2004) adapted for nymphs and adults. The synergistic activity was explored by combining each solution, based on the estimated LC50, in a 1:1 ratio (FIP: EUG, FIP: CAR and EUG: CAR). CompuSyn software was used to evaluate the various pairwise combinations of FIP, EUG and CAR, checking if there was synergism or antagonism between them. FIP and EUG and FIP and CAR showed combination index (CIn) values above 1.45, indicating antagonism. The synergistic activity between EUG and CAR was verified against all unfed phases of R. sanguineus, since the CIn was below 0.70, a value that indicates synergism. The combination of fipronil with either eugenol or carvacrol presented antagonistic effects against R. sanguineus larvae. On the other hand, carvacrol and eugenol had excellent pharmacological synergism against all tick stages with mortality values in the range of 80 to 100%, including the adult stage, which is less susceptible than immature stages.

Larvicidal activity in vitro of essential oils against Cochliomyia hominivorax

Cochliomyia hominivorax, from the family Calliphoridae, is responsible for causing most myiases in domesticated animals in Brazil. As alternatives to conventional treatments, essential oils (EOs) could possibly be used as natural control of ectoparasites. The aim of this study was to evaluate the in vitro activity of EOs from Salvia sclarea L., Rosmarinus officinalis L., Lavandula hybrida Reverchon, Citrus bergamia Risso, Citrus paradisi L., Juniperus virginiana L., Copaifera reticulata Ducke, Illicium verum Hook f., Pelargonium roseum, Cymbopogon winterianus Jowitt, Cymbopogon flexuosus Steud, Eugenia caryophyllus Spreng, Cinnamomum cassia Presl, Thymus vulgaris L. and Origanum vulgare L. against third-instar larvae of C. hominivorax. To evaluate the mortality rate, filter paper tests were performed at different concentrations and verified after 24 h and 48 h. Essential oils of T. vulgaris, O. vulgare and I. verum induced 100% mortality in the screening test, and their main active components (thymol, carvacrol and anethol, respectively) were also tested alone. In this new test, lethal concentrations (LC50) after 24 h and 48 h, respectively, were 407.1 and 314.2 µg.cm-² for T. vulgaris, 540.9 and 253.8 µg.cm-² for O. vulgare, 314.2 µg.cm-² (after 48 h) for I. verum, 255.6 and 102.3 µg.cm-² for thymol, 970.5 and 931.1 µg.cm-2 for carvacrol and 559.4 µg.cm-2 (after 48 h) for anethol. These results showed the potential of these EOs and their main components for development of ectoparasiticides for veterinary use, especially T. vulgaris EO and thymol.

Prevalence of gastrointestinal parasites in domestic cats (Felis catus) diagnosed by different coproparasitological techniques in the municipality of Seropédica, Rio de Janeiro

The objectives of this work were to investigate the occurrence of parasites in feces of cats, compare different coproparasitological techniques for their diagnosis and determine associations with parasitism. The samples were processed using three different coproparasitological techniques: centrifugal flotation in sucrose, centrifugal flotation in ZnSO4 and simple sedimentation. The parasitic association between parasitism and variables such as age, sex and fecal consistency was performed using the chi-square test or the G test with a significance level of 5%. A total of 237 samples were analyzed, of which 93 (39.2%) were positive, being Ancylostoma spp. (17.3%), Giardia intestinalis (12.2%), Platynosomum illiciens (8.0%), Cystoisospora spp. (6.3%), Toxoplasma gondii/ Hammondia hammondi (3.4%), Diphyllobothriidae (2.1%), Toxocara spp. (1.7%), Dipylidium caninum (1.3%) and Mesocestoides spp. (0.8%). In the parasitism association analysis, it was possible to verify a statistical difference in the age category for Cystoisospora spp. (p=0.001) observing a strong relationship between parasitism and young animals, the association with sex proved to be important for P. illiciens (p<0.001) with a higher frequency of parasitized females and fecal consistency revealed to be related to the parasites G. intestinalis (p=0.007) and P. illiciens (p=0.033) showing a higher number of positive animals for these parasites with normal fecal consistency. In conclusion, we observed a higher occurrence of Ancylostoma spp. and G. intestinalis in fecal samples from domestic cats received in routine diagnoses and the presence of other parasites with zoonotic potential, as well as the relationship of these diagnosed parasites with the categories sex, age and fecal consistency.

Dogs infected by Dirofilaria immitis: a threat to the health of human and non-human animals in Rio de Janeiro, Brazil

This study aimed to investigate the presence of Dirofilaria immitis microfilaremia in dogs from two regions of the state of Rio de Janeiro, Brazil, where heartworm infections are highly prevalent. Blood samples were collected from dogs aged > 12 months, independent of the use of preventatives. All samples obtained and analyzed using Knott's modified test by the investigators. A total of 133 blood samples were tested, and D. immitis microfilariae were detected in 29 of them, resulting in an occurrence of 21.8%. The percentage of dogs with microfilaremia detected raises concerns for pet families, one health professionals, and small animal practitioners. Microfilaremic dogs are the richest source of infection for the mosquitoes, increasing the risk of transmission. Therefore, the stakeholders in One Health must raise concerns regarding the health of wild animals, as wild canids and other species of wild animals are exposed to the risk of D. immitis infection. In addition, humans can get infected and develop human pulmonary dirofilariasis. In conclusion, the presence of dogs with microfilaremia potentiates opportunities for D. immitis transmission, exposing all animals, wild or domestic, human or non-human to the disease.

Evaluation of the susceptibility to fipronil of Rhipicephalus microplus larvae from egg masses incubated at different times of oviposition

The objective of this work was to evaluate the susceptibility of R. microplus larvae from different oviposition times to fipronil. The LPT was performed in sextuplicate, at concentrations of 18.75, 37.5, 75, 150 and 300 µg.mL^-1. The LC₅₀ found for the egg masses incubated with +7, +14 and +21 days were respectively 105.87, 110.71 and 121.22 µg.mL^-1. The larvae originating from egg masses from the same group of engorged females, incubated on different days, presented similar mortality rates compared to the evaluated fipronil concentrations, facilitating the maintenance of laboratory colonies of this tick species.

Fluazuron orally administered to guinea pigs: pharmacokinetic and efficacy against Amblyomma sculptum

Background

Brazilian spotted fever (BSF), the most lethal tick-borne disease in the Western Hemisphere, is caused by the bacterium Rickettsia rickettsii and transmitted by the bite of Amblyomma sculptum. Capybaras are considered primary hosts of this tick and amplifier hosts of R. rickettsii, generating new infected lineages of A. sculptum in BSF-endemic areas. To define a possible treatment regimen for controlling the tick A. sculptum in capybaras, the aim of this study was to establish an effective fluazuron (FLU) dose to control A. sculptum larvae in artificially infested guinea pigs.

Methods

In Study I (pharmacokinetic and pharmacodynamic analysis), 24 guinea pigs were divided into four equal groups: control group (CG; untreated) and treated groups receiving FLU administered by gavage in three doses: G1—1 mg/kg, G2—5 mg/kg and G3—10 mg/kg, once a day for 15 days (d0 to d + 14). Blood samples were collected from the animals of the treated groups before and at d + 1, + 2, + 4, + 7, + 15 and + 21. The guinea pigs were artificially infested at d + 7 with A. sculptum larvae, and specimens were recovered at d + 11 to d + 14 and kept in a climatized chamber for 14 days. In Study II (evaluation of pharmacokinetic parameters), one group of eight animals received FLU administered by gavage in a single dose of 10 mg/kg, and blood samples were collected before and on day 0 (8 h after treatment), + 1, + 4, + 7, + 15, + 21 and + 28 after single FLU administration. FLU was analyzed in plasma samples by high-performance liquid chromatography with ultraviolet detection.

Results

FLU plasma concentrations increased quickly, indicating rapid absorption, and decreased slowly. Some larvae from all treated groups exhibited morphological and behavioral changes. FLU interfered in molting, and the efficacy obtained was 100% for all treated groups.

Conclusions

The results offer promising perspectives for the development of a palatable feed cube containing FLU for free-living capybaras to control A. sculptum and also to prevent BSF in areas where capybaras have been shown to play a primary role.

Insecticidal activity in vitro of the essential oil of Pogostemon cablin against Ctenocephalides felis felis

The aim of this study was to evaluate the in vitro insecticidal activity of the essential oil (EO) of P. cablin against immature and adult stages of C. felis. The chemical composition of P. cablin EO was determined by gas chromatography (GC). To evaluate the insecticidal activity, the egg, larva, pupa, and adult stages of C. felis were exposed to different concentrations of P. cablin EO diluted in acetone and impregnated in filter paper in a concentration range of 25 to 200 μg.cm^-2. After exposure, the material was incubated in climatized chambers and mortality assessment was performed after 24 h for the larval and adult stages, 72 h for the egg stage and 15 days for the pupal stage. After GC analysis, the major constituents of the EO of P. cablin were found to be patchoulol (27.4%), α-bulnesene (19.7%) and α-guayene (15.0%). The of mortality percentage was 100% at the concentration of 200 μg.cm^-2 for all stages. The LCs₅₀ values were 46.1, 49.2, 60.6 and 62.7 µg.cm^-2, respectively for the pupal, egg, larva and adult stages. Based on the results obtained, we can conclude that the EO of P. cablin contained patchoulol, α-bulnesene, and α-guayene as major constituents and had insecticidal activity against the immature and adult stages of C. felis.

Resistance of Haemonchus contortus to monepantel in sheep: first report in Espírito Santo, Brazil

The objective of this study was to provide the first report of resistance of Haemonchus contortus to monepantel in sheep in Espírito Santo. The study was conducted in a property with history of monepantel use since 2014 and register of low efficacy in studies conducted over the past few years with fecal egg count reduction test. Lambs born on the property (males and females aged approximately 100 days) were selected and after eggs per gram of feces (EPG) analysis on fecal samples, these were divided into two groups: a group treated with monepantel (2.5 mg / Kg) and a control group without anthelmintic treatment. Seven days later, the animals were euthanized to recover parasites from the gastrointestinal tract. The efficacy of the treatment was 61.35% against H. contortus, thus proving that anthelmintic resistance to monepantel was present.

Oral pharmacokinetic profile of fipronil and efficacy against flea and tick in dogs

Fipronil (FIP) is an ectoparasiticide of the phenylpyrazole class, used in veterinary medicine in topical form. Supported by evidence of uncontrolled human exposure to FIP and environmental damage caused by commercially available formulations, its use by oral administration has become promising. The effectiveness of FIP against the flea Ctenocephalides felis felis and the tick Rhipicephalus sanguineus and its pharmacokinetics and main active metabolite, fipronil sulfone (SULF) were evaluated after single oral administration of tablets in three different doses (2, 4, and 6 mg/kg) in dogs. Through the plasma concentration curves, it was possible to observe that the FIP showed rapid absorption and metabolization and slow elimination. The values of C_max (β = 0.7653) and AUC_{0- t} (β = 0.3209) did not increase proportionally with increasing dose. At 48 h after treatment, doses of 4 mg/kg (AUC_{0- t}  = 442.39 ± 137.35 µg/ml*h) and 6 mg/kg (AUC_{0- t}  = 421.32 ± 102.84 µg/ml*h) provided 100% and 99% efficacy against fleas, and 95% and 98% against ticks, respectively. The estimated EC₉₀ of FIP +SULF was 1.30 µg/ml against C. felis felis and 2.16 µg/ml against R. sanguineus. The correlation between the FIP pharmacokinetic and efficacy data demonstrated its potential for oral administration in the form of tablets for the control of ectoparasites in dogs, as a safer alternative for animals, humans, and the environment, aligned with the One Health concept.

Furuncular myiasis caused by Dermatobia hominis in five cats and efficacy of topical fluralaner for its treatment

BACKGROUND

Dermatobia hominis (D. hominis) is a botfly that causes furuncular myiasis in several species of domestic and wild animals. However, reports of feline infestation by larvae of this dipteran are rare.

OBJECTIVE

To report the natural occurrence of furuncular myiasis caused by D. hominis in five cats and the efficacy of topical fluralaner for its treatment.

ANIMALS

Five adult mixed-breed cats (four males, one female) were diagnosed and treated, all living in the state of Rio de Janeiro, Brazil.

RESULTS

The cats were treated with topical fluralaner. After this treatment, the larvae were dead after 24 h in three cats and after 48 h in two. There was spontaneous expulsion of larvae in two cats, and it was necessary to perform manual expression for removal of dead larvae in the other three cats.

CONCLUSIONS AND CLINICAL IMPORTANCE

Dermatobia hominis can cause furuncular myiasis in cats, although this appears to be less common than in other animal species. Topical fluralaner proved to be effective in the treatment of this parasitic disease.

Platynosomum illiciens (Trematoda: Dicrocoeliidae) in a hybrid marmoset (Callithrix sp.) in the Municipality of Seropédica, RJ, Brazil - Case report

Platynosomum illiciens is a liver trematode encountered infecting mainly felids although it has also been reported in birds and in additional mammalian species, including non-human primates. The current study reports a natural P. illiciens infection primate of the genus Callithrix. The diagnosis was made using a combination of copro-parasitological techniques, morphological evaluation of adult specimens recovered from the liver during necropsy, and molecular analyses. Eggs were brown in color, oval, operculated, and contained a miracidium. Adult specimens recovered during necropsy were measured and showed dimensions compatible with P. illiciens. Molecular characterization of the trematode involved amplification by polymerase chain reaction (PCR), in combination with nucleotide sequencing, of an approximately 900 base pairs fragment corresponding to 18S-ITS1-5.8S ribosomal DNA. Sequenced amplicons showed 100% nucleotide identity with sequences deposited in the GenBank database as derived from specimens of P. illiciens recovered from cats in Malaysia and Brazil. It was concluded that the morphological and molecular analyses presented herein, confirmed the identification of the trematode recovered as P. illiciens.

Efficacy of Oral Sarolaner for the Treatment of Feline Otodectic Mange

Otodectes cynotis is a mite with a cosmopolitan distribution that is the primary agent for the development of otitis externa in feline species. The aim of this study was to evaluate the efficacy of the oral administration of sarolaner for the treatment of feline otodectic mange. We used 20 adult cats of both sexes that were naturally infested with O. cynotis. The mite infestation scoring was performed by video-otoscopy before treatment. The cats were randomized according to the infestation score and divided into two groups (treated and control). The treated group underwent oral administration of sarolaner in a single dose of 2–4 mg/kg. The evaluations were performed by video-otoscopy to evaluate the reduction of infestation score 2, 4, 6, 24 and 48 h and 7, 14, 21 and 28 days after medication. At the end of the study, the cats were sedated to enable the recovery of live and dead mites to determine efficacy. No adverse effects or laboratory changes were observed in these cats. Sarolaner showed 100% efficacy 48 h after treatment. Based on the results, a single oral dose of sarolaner was effective in controlling otodectic mange in naturally infested cats.

AVALIAÇÃO DA ATIVIDADE in vitro DO FIPRONIL CONTRA LARVAS NÃO ALIMENTADAS DE Dermacentor nitens

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 27ºC 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.

CARACTERIZAÇÃO CELULAR DA HEMOLINFA DE FÊMEAS INGURGITADAS DE Amblyomma sculptum

O carrapato Ambyomma sculptum, encontrado as várias regiões do Brasil, é conhecido como “carrapato estrela” ou “carrapato do cavalo” e parasita animais domésticos, silvestres e humanos, sendo o principal transmissor de Rickettsia rickettsii, agente etiológico da Febre Maculosa Brasileira. Possui grande importância veterinária por causar diversos prejuízos aos seus hospedeiros. Estudos sobre sistema imunológico de carrapatos buscam avaliar alterações na resposta celular hemolinfática que faça entender a imunologia e fisiologia envolvida nos mecanismos de controle e resistência. O objetivo deste trabalho foi caracterizar quantitativamente e morfologicamente os hemócitos da hemolinfa de fêmeas ingurgitadas de A. sculptum. A hemolinfa foi coletada por uma perfuração da cutícula na parte dorsal do carrapato e depositada em lâmina de vidro para confecção dos esfregaços que foram corados por solução de Giemsa. Foi realizada a contagem diferencial de hemócitos com base na morfologia observada em microscópio óptico em aumento de 1000 vezes, através da identificação das 100 primeiras células encontradas. A avaliação dos tamanhos de cada célula e de seus componentes foi realizada por leitura das lâminas confeccionadas para contagem diferencial dos hemócitos com o auxílio de um microscópio óptico com luz polarizada. A contagem total de hemócitos foi realizada com auxílio de microscópio óptico e Câmara de Neubauer. A caracterização celular revelou que o carrapato A. sculptum apresenta média de 1024 céls/μL e seis tipos celulares que se distribuem de forma distinta na hemolinfa. Os granulócitos foram os hemócitos mais frequentes (78%), seguidos de plasmatócitos (10%), prohemócitos (6%), esferulócitos (5%), oenocitóide (1%) e adipohemócito com menos de 1% de frequência. De acordo com as características morfológicas os granulócitos foram descritos com tamanho médio de 22x19 μm, sendo células de tamanhos variados e de formas arredondadas a elípticas, com citoplasma coberto de grânulos. Os plasmatócitos se apresentaram polimórficos com citoplasma vacuolizado ou granular e foi o grupo com maior variação de forma e tamanho com medidas médias de 24x10 μm. Os prohemócitos foram o menor tipo celular observado medindo em média 13x11 μm, se apresentando em formato arredondado, com núcleo central e escasso citoplasma. Os esferulócitos caracterizaram-se como células arredondadas (tamanho médio de 22x20μm) com estruturas presentes de forma abundante no citoplasma, as esférulas. Os oenocitóides apresentaram tamanho intermediário (média: 23x19μm), com forma arredondada, margens irregulares e citoplasma com granulações refráteis e aspecto esponjoso. Os adipohemócitos, raramente encontrados, são células de tamanho variável, margens citoplasmáticas irregulares, vesículas refringentes no citoplasma e a quantidade observada não foi suficiente para realização da conferência das medidas com segurança estatística. Conclui-se que a partir da microscopia óptica foi possível determinar o valor médio do total de hemócitos circulantes, classificados morfologicamente como granulócitos, plasmatócitos, prohemócitos, esferulócitos, oenocitóides e adipohemócitos, e determinar a frequência média de cada hemócito na hemolinfa de A. sculptum, onde os granulócitos são o tipo mais frequentes.

EFICÁCIA DO PRODUTO A BASE DE EPRINOMECTINA 2% CONTRA Haemonchus placei, Cooperia pectinata, Cooperia punctata, Oesophagostomum radiatum E Trichostrongylus axei EM BOVINOS ARTIFICIALMENTE INFECTADOS

Prejuízos causados por helmintoses em bovinos ocorrem por ação direta, pelos danos ao rebanho, e indireta, resultantes do custo financeiro para o controle parasitário. A prática de controle estratégico, com utilização correta de anti-helmínticos e manutenção de cargas parasitárias, podem gerar resultados satisfatórios para um rebanho quanto a aspectos de produtividade. A eprinomectina, , pertence ao grupo das lactonas macrocíclicas e possui ação endectocida. O estudo teve como objetivo avaliar a atividade anti-helmíntica da eprinomectina 2%, pela via injetável subcutânea, empregada na dose de 200mcg/Kg de peso corporal, em bovinos artificialmente infectados por nematódeos gastrintestinais. Doze bovinos mestiços foram infectados artificialmente com uma cultura mista de 150.000 L3 de uma cultura de Haemonchus placei, Cooperia pectinata, Cooperia punctata, Oesophagostomum radiatum e Trichostrongylus axei (CEUA IV/UFRRJ 9867250516). Após 42 dias os animais foram divididos em grupo controle e tratado, randomizados de acordo com as contagens médias de OPGs (ovos por gramas de fezes) realizadas nos dias -7 e -2. No dia 0 os animais tratados. Foram realizadas as contagens de OPGs dos animais nos dias +1, +3, +5, +7 +9, +11 e +13. Os animais foram eutanasiados e necropsiados nos dias +14 e +15. O número médio das contagens de OPGs e o número de helmintos presentes nos bovinos tratados foram estatisticamente menores que nos bovinos do grupo controle (p≤0,05). No grupo tratado foram encontrados por animal uma média de 355 espécimes de C. pectinata, 84,5 de T. axei, 445,67 de H. placei, 818,33 de C. punctata e 29,17 de O. radiatum. Já no grupo tratado a média de parasitos encontrados por animal foi de zero para C. pectinata e T. axei, 3,33, 20 e 1,33 para H. placei, C. punctata e O. radiatum respectivamente. Houve eficácia de 100% para C. pectinata e T. axei, 99,25% para H. placei, 97,56% C. punctata e 95,43% para O. radiatum. Como no presente estudo, testes anti-helmínticos controlados e estudos de redução de OPG realizados em outros países relatam a eficácia da eprinomectina, gerando uma nova perspectiva para o controle de helmintos gastrintestinais de bovinos, com o uso seguro de uma lactona macrociclica em vacas em lactação. Conclui-se que o produto se mostrou efetivo contra as espécies H. placei, C. pectinata e T. axei e efetivo contra C. punctata O. radiatum. em teste controlado.

EFICÁCIA MOSQUICIDA DE UMA ASSOCIAÇÃO “POUR-ON” CONTENDO CLORPIRIFÓS 50% e CIPERMETRINA 20%, NO CONTROLE DA MOSCA DOS CHIFRES (Haematobia irritans) EM BOVINOS NATURALMENTE INFESTADOS

A mosca-dos-chifres (Haematobia irritans) é um pequeno ectoparasita díptero hematófago que parasita o bovino, causando prejuízos econômicos estimados em 3,24 bilhões de dólares, determinados principalmente pela espoliação e o incomodo ao animal que acarretam perda de peso e diminuição da produção leiteira dentre outros aspectos da produção. O estudo, aprovado pela Comissão de Ética no uso de Animais do Instituto de Veterinária da UFRRJ (CEUA Nº 4515061217), objetivou avaliar a eficácia da associação a base de clorpirifós e cipermetrina, contra H. irritans em bovinos naturalmente infestados. Foram utilizados 30 bovinos mestiços e o ranqueamento foi feito com base nas médias das contagens do número total de moscas, em ambos os lados do animal, realizadas nos dias D-3 e D-1. Os animais selecionados foram divididos em dois grupos, Grupo Controle (GC) e Grupo Tratado (GT), contendo em cada um, 15 animais. No dia D0, a associação do medicamento foi administrada por via tópica nos animais do GT em dose única de 5 litros por pulverização com auxílio de uma bomba costal. Os animais foram contidos em brete e tratados individualmente. O efeito contra H. irritans foi avaliado por meio de contagens do número de moscas vivas contidos em ambos os lados dos animais nos dias experimentais D+1, D+3, D+7, D+14, D+21, D+28, D+35 e D+42. Diferenças estatísticas significativas (p≤0,05) foram verificadas nas médias das contagens de moscas em todos os dias após tratamento dos animais. Os resultados das médias aritméticas de contagens de moscas foram os seguintes para o grupo controle (GC): 95,20 (D+1),  74,07 (D+3),  100,80 (D+7),  79,07 (D+14),  65,53 (D+21),  75,47 (D+28),  92,87  (D+35),  76,93 (D+42); e para o grupo tratado (GT): 0,53 (D+1), 0,40 (D+3), 1,27 (D+7), 4,27 (D+14), 11,80 (D+21), 16,67 (D+28), 29,47 (D+35), 40,07 (D+42). A eficácia observada por dia experimental foi de: 99,4% (D+1), 99,46% (D+3), 98,74% (D+7), 94,60% (D+14), 81,99% (D+21), 77,92% (D+28), 68,27% (D+35) e 47,92% (D+42). Através dos resultados da contagem de H. irritans pôde-se observar antes do tratamento variações de 34 a 114 moscas nos animais. Os resultados demostraram que a associação à base de clorpirifós 50% e cipermetrina 20%, empregada por pulverização, foi efetiva para o tratamento de bovinos naturalmente infestados por H. irritans, apresentando níveis de eficácia acima de 80% por até 21 dias após tratamento.

Platynosomum illiciens (TREMATODA: DICROCOELIDAE) EM SAGUI (Callithrix spp.) NO MUNICÍPIO DE SEROPÉDICA, RJ - RELATO DE CASO

A espécie Platynosomum illiciens é um trematódeo do trato biliar, principalmente de felídeos, tendo sido relatado também em aves e outras espécies de mamíferos como em primatas não humanos. Portadores de uma ampla variação morfológica, o gênero Platynosomum é discutido por diversos autores quanto as suas características morfológicas. O objetivo deste estudo foi identificar e relatar o parasitismo por P. illiciens em um primata não humano do gênero Callithrix que vivia em um Centro de Triagem de Animais Silvestres no município de Seropédica RJ. O diagnóstico foi através de técnicas coproparasitológicas, avaliação morfológica de espécimes adultos recuperados através de necrópsia e análise molecular. A avaliação da amostra fecal foi realizada com as técnicas coproparasitológicas centrífugo flutuação simples com solução de sacarose e sedimentação em formalina-éter. Onde, foram encontrados ovos de coloraçao marrom, ovalados, operculados e com um miracidio em seu interior. A análise morfológica dos ovos indicou as dimensões dos diâmetros maior e menor, respectivamente, como 41,24µm (32,62- 46,76) e 28,13µm (22,05-37,67), com média de 1,79µm de espessura de parede. A análise morfológica dos espécimes adultos foi feita após o animal vir a óbito naturalmente.  A mensuração foi feita a partir das medidas de comprimento e largura, respectivamente, do corpo (6013-1367 µm), ventosa oral (418-409 µm), faringe (107-127 µm), acetábulo (403-418 µm), testículo direito (846-470 µm), testículo esquerdo (910-515 µm), ovário (385-281 µm) e bolsa do cirro (500-145 µm). A detecção de DNA do trematódeo foi realizada por meio da reação em cadeia da polimerase (PCR). As sequências obtidas foram analisadas e comparadas aos isolados disponíveis na base de dados da plataforma GenBank. A análise filogenética indicou que as sequências dos fragmentos de rDNA 18S-ITS1-5.8S amplificadas a partir do trematódeo em questão, mostraram 100% de similaridades nucleotídicas com as sequências do GenBank KU987674 e MH156567 depositadas como derivadas de P. fastosum e P. illiciens recuperadas de fígado de gatos no Vietnã e nos Estados Unidos, respectivamente, concluindo que a espécie analisada se trata do P. illiciens.

In vitro acaricidal activity of different ectoparasiticide classes against Amblyomma sculptum larvae

Zoonoses are major causes of morbidity and mortality worldwide. Among them, Brazilian Spotted Fever (BSF) is an important one that occurs in some regions of South America and can be transmitted by the "star tick" Amblyomma sculptum. Application of acaricides against the larval stage is important as strategy of population control. However, there is still a deficiency of studies on chemical control of A. sculptum and the present work aims to evaluate the in vitro acaricidal activity of cypermethrin, flumethrin, deltamethrin, fipronil, coumaphos and chlorpyrifos against A. sculptum larvae. Bioassays were performed using the larval immersion test method. A discriminatory analysis between the antiparasitic classes most used for tick control was carried out, which made it possible to determine the classes with higher potential for controlling A. sculptum larvae. Our results showed that A. sculptum larvae present highest sensitivity to the synthetic pyrethroid group, followed by the phenylpyrazole, organophosphate and macrocyclic lactone groups. These findings may support studies on improvement of tick control as in animals as in the environment.

Activity of Syzygium aromaticum essential oil and its main constituent eugenol in the inhibition of the development of Ctenocephalides felis felis and the control of adults

The aim of this study was to evaluate the in vitro activity of Syzygium aromaticum essential oil (SAEO) and its main constituent eugenol (EG) against adult fleas and their action in the maturation of eggs into adults of Ctenocephalides felis felis. In order to evaluate the pulicidal activity, 10 adult fleas were exposed to a filter paper impregnated with SAEO and EG at increasing concentrations of 0.047; 0.094; 0.188; 0.375; 0.750; 1.50; 3.00; 6.00; 12.00 and 24.00 μg cm^-2. Flea mortality was evaluated 24 and 48 h after exposure. In order to evaluate the inhibition of the maturation of eggs into adults, 10 eggs were exposed to filter paper impregnated with SAEO and EG at the same concentrations used in the pulicidal test, and the evaluation was performed 30 days after incubation. Untreated repetitions were maintained in both studies (control group). The lethal concentration 50 (LC₅₀) of pulicidal activity to SAEO was 5.70 μg cm^-2 in 24 h and 3.91 μg cm^-2 in 48 h. The LC₉₀ was 16.10 μg cm^-2 and 15.80 μg cm^-2 in 24 and 48 h, respectively. The LC₅₀ of inhibition of the maturation of eggs into adults was 0.30 μg cm^-2 and the LC₉₀ 3.44 μg cm^-2. The LC₅₀ of pulicidal activity to EG was 2.40 μg cm^-2 in 24 h and 1.40 μg cm^-2 in 48 h; the LC₉₀ was 8.10 μg cm^-2 and 3.70 μg cm^-2 in 24 h and 48 h, respectively. The LC₅₀ of inhibition of the maturation of eggs into adults was 0.10 μg cm^-2 and the LC₉₀ 0.68 μg cm^-2. Based on the results obtained, it is possible to conclude that the both SAEO and EG have in vitro pulicidal activity as well as acting as inhibitors of the maturation of eggs into adults of the flea C. felis felis.

Injectable eprinomectin for cattle: Tick efficacy and pharmacokinetics

The aims of the present study were to evaluate the pharmacokinetic profile and efficacy of eprinomectin (EPM) against Rhipicephalus microplus in cattle of a new injectable form of EPM (Voss Performa®). The product was administered subcutaneously at a dose of 200 μg EPM/kg, in a single dose. The efficacy of EPM against R. microplus in cattle was evaluated through field and stall tests. Studies were performed to estimate the pharmacokinetic parameters of EPM with the purpose of better understanding the kinetics of the formulation. The formulation was effective in controlling R. microplus in both naturally and artificially infested cattle, providing efficacy greater than 95%. The results of pharmacokinetic study were C_max of 47.15 ± 22.20 ng/ml, T_max of 1.33 ± 0.492 days, T_1/2 of 2.96 ± 1.212 days, AUC_0-t of 228.08 ± 57.30 ng day ml^-1 , and AUC_0-∞ of 240.50 ± 58.44 ng day ml^-1 . Therefore, the new injectable EPM formulation becomes an important alternative for the control of cattle tick in Brazil.

Efficacy of afoxolaner in the flea control in experimentally infested cats

The aim of this study was to evaluate the efficacy of a single dose of oral afoxolaner in controlling fleas in cats. Fourteen cats were used. The cats were given identification numbers, housed individually, artificially infested with Ctenocephalides felis felis, and treated (or not) with afoxolaner. Were divided into a treatment group and a control group (n = 7/group), on the basis of the fleas count hours after an infestation applied on Day (one-by-one allocation after ordering by count). At the start of the experimental protocol (designated day 0), the treated group received afoxolaner in a single dose of 2.5 mg/kg and the control group animals received a placebo. All animals were infested with 100 C. felis felis fleas two days before day 0, as well as on days 5, 12, 19, 26, 33, 40, 47, 54, and 63, parasite loads being evaluated at 48 h after each infestation. The efficacy of afoxolaner was 100% on day 2 and remained above 98% until day 42, decreasing to 95.3% by day 63. The findings confirm that a single dose of oral afoxolaner was effective in controlling C. felis felis in cats, and there were no observed adverse events.

Fipronil Tablets: Development and Pharmacokinetic Profile in Beagle Dogs

Increased human-pet interactions have led to concerns related to the prevention and treatment of ectoparasite infestations. Fipronil (FIP) is a widely used ectoparasiticide in veterinary medicine available for topical administration; however, its use may cause damage to the owners and the environment. The aim of the study was to develop immediate-release tablets of FIP, as well as to determine its pharmacokinetic properties after oral administration in beagle dogs. The prepared FIP tablets were evaluated for pre-compression (angle of repose, speed flow, and Carr's index) and post-compression (weight variation, friability, thickness, hardness, disintegration time, and dissolution rate) parameters. Orally administered FIP at a dose of 2 mg/kg was rapidly absorbed with C_máx of 3.13 ± 1.39 μg/mL at 1.83 ± 0.40 h post treatment (P.T.) and metabolized with 1.27 ± 1.04 μg/mL at 2.33 ± 0.82 h P.T. for fipronil sulfone (SULF) (the primary metabolite). The elimination of FIP and SULF occurred slowly and had maintained quantifiable plasma levels in the blood for up to 28 days P.T. The goal of the study is aligned with the concept of One Health, which aims to collaboratively achieve the best health for people, animals, and the environment. Therefore, the use of FIP tablets for the control of ectoparasites in dogs may be a safer alternative for owners and the environment.

Efficacy of sarolaner on the treatment of myiasis caused by Cochliomyia hominivorax (Diptera: Calliphoridae) in dogs

The aim of this study was to evaluate the larval expulsion, larvicidal effect, retention rate of dead larvae and overall efficacy of sarolaner on the treatment of myiasis caused by New World screwworm Cochliomyia hominivorax in naturally infested dogs. Eight Beagle dogs received a single dose of saroalner 40 mg, with dosage ranging from 2.7 mg/kg to 3.7 mg/kg. Evaluations occurred every 15 min in the first hour, every hour for up to 6 h, and after 24 h of treatment. At 24 h post-treatment, total wound cleaning was performed, including removal and counting of remaining live and dead larvae. The animals received antibiotic, analgesic and wound cleaning support until complete wound healing. The average expulsion of the larvae was 50.9 % occurring mainly after 4 h of treatment. The larvicidal effect was 70.6 % at 6 h after treatment and 100 % at 24 h. The mean retention rate of dead larvae of sarolaner was 33.9 %, The overall efficacy was 100 %, thus making sarolaner an excellent treatment option in myiasis caused by C. hominivorax larvae in dogs.

Microscopic alterations in Fasciola hepatica from sheep treated with albendazole

Currently, albendazole is one of the most commonly used drugs because of its affordability. The objective was to evaluate the histopathology of Fasciola hepatica specimens. For this, the efficacy test was performed on sheep treated with albendazole at the dose recommended for F. hepatica, in which the helminths recovered at necropsy were counted and separated for histology. Spermatogenic cells from parasites recovered from treated and control sheep were examined by microscopy. The fecal egg-count reduction test revealed 97.06% efficacy of albendazole in the treatment of F. hepatica. Changes in testicular tubule cells started 48 hours after treatment and became evident within 72 hours, at which point it became difficult to identify cell types. Primary and secondary spermatogonia became increasingly rare and intercellular vacuolization was more evident. Signs of apoptosis, with pycnotic nuclei and evidence of keriorrexia were observed at all times. Cell debris was identified 96 hours after treatment. The results indicated that parasitic spermatogenesis was severely affected by albendazole and demonstrated the importance of the use of histopathology for the diagnosis of therapeutic efficacy in field strains.

Efficacy of a dinotefuran, pyriproxyfen and permethrin combination product against Ctenocephalides felis felis (Bouché, 1835) (Siphonaptera: Pulicidae) on artificially infested rabbits

The aim of this study was to evaluate the efficacy of an insecticidal product in rabbits that combines the neonicotinoid dinotefuran with the pyrethroid permethrin plus the insect growth regulator pyriproxyfen. Adult New Zealand rabbits (n = 12) were infested with Ctenocephalides felis felis (50 males and 50 females per rabbit) at days -7, -2, +5, +12 and +19. The control group (n = 6) received no treatment and the treated group (n = 6) received the commercial formulation, indicated for use in dogs, which was applied topically on day 0. The animals were mechanically evaluated with combs (comb test), to assess pulicidal efficacy, on days -5, +2, +7, +14 and +21. All flea removals and counts were performed by region, following the order: head, ears, neck, forelegs, dorsum, abdomen, hind limbs and tail, in order to determine the preferred sites of parasitism by the C. felis felis flea in rabbits. The distribution of fleas prevailed in the head region (about 62%), followed by the neck and back (14 and 11%, respectively). The insecticidal efficacy was calculated using arithmetic means, showing effectiveness of 100% on days +2 and +7 and 82.2% and 81.6%, on days +14 and +21, respectively. Thus the present study has shown the combination to be a viable option in the treatment and control of rabbits infested by C. felis felis.

Alterations in the oxidative metabolism of Rhipicephalus (Boophilus) microplus ticks in response to exposure to the insect growth regulator fluazuron

Abstract Aiming to characterize the potential off-target effects of fluazuron on ticks, biochemical analyses were conducted to evaluate changes in the carbohydrate metabolism of Rhipicephalus (Boophilus) microplus ticks after exposure to fluazuron. Hemolymph and fat body were collected from female ticks before and after (4, 8 and 15 days) exposure to fluazuron. Spectrophotometric analyses were done to quantify glucose concentration and lactate dehydrogenase (LDH) activity in the hemolymph and the concentration of glycogen in the tick’s fat body. High Performance Liquid Chromatography (HPLC) was employed to determine the concentration of carboxylic acids in the hemolymph and to evaluate changes in intermediary metabolic processes requiring oxygen consumption. Increases in the levels of LDH activity and lactic acid concentration indicated that fluazuron enhanced fermentative metabolism in ticks. Exposure to fluazuron was also found to increase glucose concentrations in the hemolymph over time, although no significant differences were noted daily. In addition to expanding the body of knowledge about the mode of action of fluazuron, investigations into these mechanisms may also be useful in discovering new and as yet unexplored secondary effects.

Video otoscopy as a diagnostic tool for canine otoacariasis

Canine otoacariasis, or otodectic mange, is a common parasitic disorder of dogs' ear canals caused by the mite Otodectes cynotis. Infestation can be detected through diverse protocols of varying sensitivity. We evaluated the use of video otoscopy in comparison with conventional otoscopy and cerumen examination under a microscope for diagnosingO. cynotis in dogs. Thirty-five dogs were evaluated bilaterally for the presence of ear mites, using a veterinary otoscope (Gowlands®), a video otoscope (Welch Allyn®) and the gold-standard technique of examination of swab-collected cerumen under a microscope. Each ear was considered to represent one sample, and 69 ears were examined, since one dog presented with one completely stenotic ear canal. Ear mites were diagnosed in 59.42% (41/69) through video otoscopy. The same 41 infested ear canals were detected by means of cerumen examination under a microscope, whereas conventional otoscopy was able to diagnose mites in only 39.13% (27/69). This difference was statistically significant (p < 0.001). Video otoscopy proved to be superior to conventional otoscopy, and equivalent to the gold standard for detection of O. cynotis in canine ear canals, and should be recommended for controlled trials on drug efficacy for treatment of canine otoacariasis.

[Comparative efficacy of two topical formulations containing 10% fipronil on the control of Ctenocephalides felis felis on cats]

The goal of the present study was to evaluate the comparative efficacy of two topical formulations containing 10% fipronil on the control of Ctenocephalides felis felis on cats. The trial was performed at the Laboratory of Experimental Chemotherapy in Veterinary Parasitology from the Department of Animal Parasitology of the Institute of Veterinary of the Universidade Federal Rural do Rio de Janeiro. Eighteen mixed-breed cats were divided in three groups of six animals each. One group remained without treatment (control). The other groups received as treatment the two topical formulations, a commercial reference and the novel one, both containing 10% fipronil. Treated animals received 0.5 mL of product along their cervical region. Cats were infested on days - 2, +5, +12, +19, +26 and +33. Evaluations were made using the "comb test". The first one was undertaken 4 days after the initial infestation (day +2), and others 48 hours after following infestations (days +7, +14, +21, +28 and + 35). Both tested formulations had satisfactory efficacy until day + 35. No differences were observed comparing the efficacy levels between both formulations throughout the experimental period. The novel topical 10% fipronil formulation presented desirable efficacy on the control of C. f. felis on cats.

Identificação de Cooperia punctata (Linstow, 1907) resistente a ivermectina e doramectina em um rebanho leiteiro no Estado do Rio de Janeiro, Brasil

Resistência antihelmíntica é um problema potencial para o controle de nematodas em bovinos e pode causar perdas econômicas na indústria de bovinos leiteiros e de cortes. O objetivo deste estudo foi determinar a eficácia da ivermectina, doramectna e abamectina em bezerros infectados naturalmente e experimentalmente para Cooperia punctata em um rebanho bovino leiteiro. Testes de redução da contagem de ovos fecais foram conduzidos em bezerros infectados naturalmente que foram tratados com soluções injetáveis de ivermectina, doramectina e abamectina. Amostras fecais foram colhidas no dia do tratamento, dia 0, e nos dias 7 e 14 após o tratamento e cultura de larvas foram feitas nas amostras positivas. Um teste controlado foi realizado usando 18 bezerros infectados artificialmente,alocados em três grupos com seis animais cada: Grupo I - controle, sem tratamento; Grupo II - ivermectina, solução injetável, 200µg/kg; Grupo III - doramectina, solução injetável, 200µg/kg. Amostras fecais foram colhidas no dia do tratamento, dia 0, e nos dias 3, 7, 9 e 14 após o tratamento. Nos dias 14, 15 e 16, dois animais de cada grupo foram eutanaziados e cargas de parasitos pulmonares e gastrintestinais foram determinados. Os resultados dos testes de redução da contagem de ovos fecais em bezerros infectados naturalmente mostraram redução no dia 14 após o tratamento de - 4,45 a 11,49% para ivermectina; 32.31 a 60.40% para doramectina e 85,05% para abamectina. O único parasito identificado na cultura de larvas foi Cooperia spp. O Teste Controlado mostrou uma redução da contagem de ovos fecais no dia 14 após o tratamento de 51.47% e 96.08% para ivermectina e doramectina, respectivamente. Redução da contagem de adultos neste teste controlado foi de 53.91% e 82.43% para ivermectina e doramectina, respectivamente. Somente C. punctata foi recuperado nas necropsias. Assim, esta cepa de C. punctata foi considerado resistente ao tratamento com ivermectina e doramectina e sugere uma possível resistência para abamectina pelo teste de redução da contagem de ovos fecais.

Scanning electron microscope observations on third-instar Gasterophilus nasalis (Diptera: Oestridae)

Scanning electron microscope observations studied the morphology of 3rd-instar Gasterophilus nasalis (L.). Distinctive features are illustrated in a sequence of 16 micrographs, bearing indications of structures considered of special interest. The morphology of G. nasalis is compared with that of other larval bot flies.

Scanning electron microscopy of the second-instar larva of Gasterophilus nasalis

The second-instar larva of the bot fly Gasterophilus nasalis (L.) (Diptera: Gasterophilidae) is described for the first time, based on scanning electron microscope (SEM) studies. On the pseudocephalum the larva bears an antenomaxillary sensory complex formed by the antenna (coeloconic sensilla) and the maxillary palp with a set of six coeloconic sensilla and four basiconica sensilla. The oral opening is latero-posteriorly limited by small spines, and exhibits strongly ornamented maxillae and mandibles. The thoracic and abdominal segments are circled by two bands, each with two rows (except the last segment that has one row) of backwardly pointed spines, and have cuticular depressions. Trichoid and campaniform sensilla surround the larval segments. The anterior spiracular opening is a small aperture. The terminal end of the eighth abdominal segment shows a spiracular cavity, lateral tubercles, eight basiconic and two trichoid sensilla. Each spiracular plate has two slightly curved slits, each with a serrated rima. There is a probable ecdysial scar. The findings of this ultrastructural study are compared with those other of larval flies.

Pregnancy in patients with the artificial urinary sphincter

Since 1974, 71 female patients between 3 and 25 years old have undergone implantation of the artificial urinary sphincter for treatment of urinary incontinence. Of these women 9 have become pregnant and delivered 11 normal children. In 2 women the artificial urinary sphincter was removed because of erosion before conceiving, while the remaining 7 had a functional artificial urinary sphincter in place at conception, and subsequent pregnancy and delivery. All 11 women had normal pregnancies and, aside from the normally increased frequency of urination and a slight increase in urinary leakage due to elevated pressure on the bladder from the adjacent uterus, the urinary continence was unchanged. Of the women 4 underwent cesarean section at the advice of their obstetricians and the remainder had uneventful vaginal deliveries. During the course of the pregnancies the patients or their obstetricians consulted 1 of us for advice regarding management of the delivery because of the presence of the artificial urinary sphincter. The normalcy of the pregnancies and deliveries led us to conclude that the presence of a functioning artificial urinary sphincter did not increase the risk of complications during pregnancy and childbearing.