The Role of Parasitoid Wasps, Ixodiphagus spp. (Hymenoptera: Encyrtidae), in Tick Control.

Species of Ixodiphagus (Hymenoptera: Encyrtidae) are parasitoid wasps whose immature forms develop inside ixodid and argasid ticks (Acari: Ixodida). Following oviposition by adult female wasps into the idiosoma of ticks, larvae hatch and start feeding on their internal contents, eventually emerging as adult wasps from the body of the dead ticks. Species of Ixodiphagus have been reported as parasitoids of 21 species of ticks distributed across 7 genera. There are at least ten species described in the genus, with Ixodiphagus hookeri being the most studied as an agent for biological control of ticks. Although attempts of tick control by means of this parasitoid largely failed, in a small-scale study 150,000 specimens of I. hookeri were released over a 1-year period in a pasture where a small cattle population was kept, resulting in an overall reduction in the number of Amblyomma variegatum ticks per animal. This review discusses current scientific information about Ixodiphagus spp., focusing on the role of this parasitoid in the control of ticks. The interactions between these wasps and the ticks' population are also discussed, focusing on the many biological and logistical challenges, with limitations of this control method for reducing tick populations under natural conditions.

Cutaneous filarioid nematodes of dogs in the United States: Are they emerging, neglected, or underdiagnosed parasites?

Filarioid nematodes, which are vector-borne parasites of cosmopolitan distribution, of dogs are medically important. They are represented by species in which microfilariae were found to be circulating in the bloodstream (e.g., Dirofilaria sp., Acanthocheilonema sp., and Brugia sp.) or skin-dwelling (e.g., Cercopithifilaria sp. and Onchocerca sp.). Those species whose microfilariae are detected in blood have been extensively studied, especially Dirofilaria immitis, due to their clinical importance. In recent decades, there has been an increased interest by the scientific community in filarioid nematodes whose microfilariae are detected in the skin because of the zoonotic aspect of Onchocerca lupi. In the United States (US), although D. immitis has been considered the main filarioid infecting dogs, the intense animal movement and global canine filarioid diversity may indicate that the likely presence of cutaneous filarioid nematodes is more common than previously expected. Hence, a question remains: Are these canine filarioid nematodes emerging, neglected, or simply underdiagnosed in the US? In this review, we provide an overview of pertinent information that briefly summarizes the biology of the different canine filarioid nematode species, clinical signs associated with infections, and currently available diagnostic tools using molecular and microscopy-based methods and highlight knowledge gaps where research and surveillance efforts remain necessary. The data herein presented serve as an alert to the scientific community about the importance of filarioid nematodes infecting dogs other than D. immitis. Additionally, the zoonotic potential of several filarioid species reinforces the necessity of a proper diagnosis and the need for broader surveillance to understand their diversity and distribution, to highlight the potential introduction of certain species, and mitigate their establishment in the country and new animal and human cases.

Lungworms in ruminants from Brazil: A retrospective epidemiological study over four decades.

Lungworms such as Dictyocaulus spp. in cattle and small ruminants, and Muellerius capillaris and Protostrongylus rufescens in small ruminants are important pathogens, causing respiratory disease in these livestock species. Despite their veterinary importance, lungworms of livestock have been poorly studied in certain regions of the world, including Brazil. Therefore, much of their epidemiology and economic impacts on production remain unknown. This article aims to provide a comprehensive overview of the historical and current data published on lungworm infection of domestic ruminants in Brazil. This review consisted of a comprehensive search of technical and scientific publications between January 1980 to December 2020, using online sources such as PubMed, Google Scholar and Scielo. Twenty-four articles published over the last 40 years reporting lungworms exclusively in cattle (n = 16), goats (n = 6) and sheep (n = 1) in Brazil were included. In addition, a study (n = 1) with both goats and sheep were also utilized. Overall, 12 studies were based only on post-mortem examination, five in the detection of specimens in fecal samples, and seven were based on fecal analysis followed by post-mortem examination. Out of all studies, 66.7% (n = 16) articles registered D. viviparus, 4.2% (n = 1) D. filaria, 8.3% (n = 2) P. rufescens, 16.7% (n = 4) M. capillaris, and 4.2% (n = 1) co-infection by D. filaria and M. capillaris. The existence of suitable environmental conditions, as well as intermediate and definitive hosts in Brazil contribute for the survival and development of these nematode species. The majority of the reports of lungworms originate from the Southern and Southeastern regions of the country, whose mild temperatures likely contribute to their occurrence. Finally, lungworms of ruminants have been reported over the past four decades in Brazil, but most of the information was obtained at post-mortem examination. Therefore, further studies to investigate epidemiological aspects in different hosts and regions of the country are needed.

Molecular confirmation of Fasciola hepatica infection in capybaras (Hydrochoerus hydrochaeris) from the state of Espírito Santo, Brazil.

Sixty-two fecal samples of capybara (Hydrochoerus hydrochaeris) living in eight conservation units (CUs) across the state of Espírito Santo, southeastern Brazil, were assessed for the presence of eggs of liver flukes via sedimentation. Fasciola hepatica eggs were found in 37.1% (23/62) of the samples. Positive samples were found in six CUs (75%), three CUs located in the southern region of the state and three others in the metropolitan region of the capital city of Vitória. Identification of Fasciola hepatica eggs collected from capybara fecal samples were based on morphology, and confirmed using molecular methods. Our results suggest that capybaras may serve as a wild reservoir host for F. hepatica, possibly contributing to the epidemiology and geographic range expansion of this zoonotic parasite across its vast range of distribution in South America.

Molecular confirmation of Fasciola hepatica infection in capybaras (Hydrochoerus hydrochaeris) from the state of Espírito Santo, Brazil / Confirmação molecular de infecção por Fasciola hepatica em capivaras (Hydrochoerus hydrochaeris) do Estado do Espírito Santo, Brasil

Abstract Sixty-two fecal samples of capybara (Hydrochoerus hydrochaeris) living in eight conservation units (CUs) across the state of Espírito Santo, southeastern Brazil, were assessed for the presence of eggs of liver flukes via sedimentation. Fasciola hepatica eggs were found in 37.1% (23/62) of the samples. Positive samples were found in six CUs (75%), three CUs located in the southern region of the state and three others in the metropolitan region of the capital city of Vitória. Identification of Fasciola hepatica eggs collected from capybara fecal samples were based on morphology, and confirmed using molecular methods. Our results suggest that capybaras may serve as a wild reservoir host for F. hepatica, possibly contributing to the epidemiology and geographic range expansion of this zoonotic parasite across its vast range of distribution in South America.

Resumo Sessenta e duas amostras fecais de capivaras (Hydrochoerus hydrochaeris), coletadas em oito unidades de conservação (UCs) no estado do Espírito Santo, Brasil, foram avaliadas quanto à presença de ovos de Fasciola hepatica por método de sedimentação. Ovos foram encontrados em 37,1% (23/62) das amostras, abrangendo seis UCs (75%), três UCs, localizadas na região sul do Estado, e outras três na região metropolitana da capital Vitória. A identificação dos ovos de F. hepatica coletados nas amostras fecais foi baseada na morfologia e confirmada por métodos moleculares. Os resultados sugerem que as capivaras podem servir como hospedeiros reservatórios selvagens para F. hepatica, possivelmente contribuindo para a epidemiologia e a expansão geográfica deste parasito zoonótico em sua vasta distribuição na América do Sul.

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.

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 diagnosing O. 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.

Video otoscopy as a diagnostic tool for canine otoacariasis / Video otoscopia como técnica diagnóstica para otoacaríase canina

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 diagnosing O. 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.

A sarna otodécica ou otoacaríase canina é uma doença parasitária comum em cães causada pelo ácaro Otodectes cynotis. A infestação no conduto auditivo dos animais pode ser diagnosticada através de diversos protocolos com diferentes sensibilidades. Avaliamos o uso da video otoscopia comparada à otoscopia convencional e à observação do cerumem sob microcópio, no diagnóstico de O. cynotis em cães. Trinta e cinco cães foram avaliados bilateralmente para a presença de ácaros através do uso de um otoscópio veterinário (Gowlands®), um vídeo otoscópio (Welch Allyn®) e pela técnica padrão, que é o exame microscópico do cerumem coletado por um "swab". Cada orelha foi considerada uma unidade, sendo que foram examinadas 69 orelhas, pois um cão apresentou o conduto auditivo completamente estenosado. Os ácaros foram detectados pela video otoscopia em 59.42% (41/69) dos condutos. Os mesmos 41 infestados foram diagnosticados através do exame do cerumem sob microscopia óptica, enquanto a otoscopia convencional identificou os parasitos em apenas 39.13% (27/69) das orelhas. A diferença foi estatisticamente significativa (p < 0,001). A video otoscopia provou ser superior a otoscopia convencional para o diagnóstico do ácaro O. cynotis nos condutos auditivos de cães e deve ser recomendada para ensaios controlados de eficácia de medicamentos para o tratamento da otocaríase canina.

[Evaluation of different meridic diets upon adult emergence of Ctenocephalides felis felis (Siphonaptera: Pulicidae)]. / Avaliação de diferentes dietas merídicas sobre a emergência de adultos de Ctenocephalides felis felis (Siphonaptera: Pulicidae).

The objective of the present study was to evaluate the influence of meridic diets composed by blood from different animal species upon the adult emergence of Ctenocephalides felis felis fleas. Six artificial diets containing dried blood of cattle (standard), dogs, rabbit and chicken, combined with sand or sand/wheat bran were prepared. For each diet six samples containing ten C. f. felis eggs were evaluated. After 25 days of incubation, samples were assessed for adult emergence. The number of emerge fleas for diets composed by bovine, canine, rabbit and chicken combined with sand/ wheat bran was approximately eight fleas. Diets composed by bovine and canine combined with sand, this emergence was approximately one flea, for both. It can be concluded that the blood origin do not alter significantly C. f. felis adult emergence rate. Therefore, blood from any available animal species can be used for artificial diet formulation, combined with wheat bran in order to supply any nutritional losses occurred during blood dehydration.

Avaliação de diferentes dietas merídicas sobre a emergência de adultos de Ctenocephalides felis felis (Siphonaptera : Pulicidae) / Evaluation of different meridic diets upon adult emergence of Ctenocephalides felis felis (Siphonaptera: Pulicidae)

O objetivo do presente trabalho foi avaliar a influência de dietas merídicas compostas por sangue de diferentes espécies animais sobre a emergência de adultos da pulga Ctenocephalides felis felis. Foram utilizadas seis dietas artificiais contendo areia e sangue desidratado de cão, boi, coelho e galinha, acrescidas ou não com farelo de trigo. Foram realizadas seis repetições contendo dez ovos de C. f. felis para cada dieta. Após 25 dias de incubação, os ovos foram quantificados e avaliados quanto à emergência de adultos. O número de pulgas emergidas para dietas com sangue de boi, cão, coelho e galinha, com areia e farelo de trigo, foi de aproximadamente oito pulgas. Para as dietas contendo apenas sangue de boi ou de cão e areia, essa emergência foi de aproximadamente uma pulga para ambas. Conclui-se que a origem do sangue empregado na elaboração da dieta não interfere significativamente no percentual de emergência de adultos de C. f. felis. Portanto, pode-se optar pela espécie animal disponível para o preparo da dieta artificial, aliada à suplementação com farelo de trigo, para suprir uma eventual perda nutricional decorrente da desidratação do sangue.

The objective of the present study was to evaluate the influence of meridic diets composed by blood from different animal species upon the adult emergence of Ctenocephalides felis felis fleas. Six artificial diets containing dried blood of cattle (standard), dogs, rabbit and chicken, combined with sand or sand/wheat bran were prepared. For each diet six samples containing ten C. f. felis eggs were evaluated. After 25 days of incubation, samples were assessed for adult emergence. The number of emerge fleas for diets composed by bovine, canine, rabbit and chicken combined with sand/wheat bran was aproximally eight fleas. Diets composed by bovine and canine combined with sand, this emergence was aproximally one flea, for both. It can be concluded that the blood origin do not alter significantly C. f. felis adult emergence rate. Therefore, blood from any available animal species can be used for artificial diet formulation, combined with wheat bran in order to supply any nutritional losses occurred during blood dehydration.

[Comparative efficacy of two topical formulations containing 10% fipronil on the control of Ctenocephalides felis felis on cats]. / Eficacia comparativa de formulacoes de uso topico contendo fipronil 10% no control de Ctenocephalides felis felis em gatos.

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.

Eficácia comparativa de duas formulações de uso tópico contendo fipronil 10 por cento no controle de Ctenocephalides felis felis em gatos / Comparative efficacy of two topical formulations containing 10 percent fipronil on the control of Ctenocephalides felis felis on cats

No presente trabalho, foram avaliadas, comparativamente, duas formulações comerciais tópicas, contendo 10 por cento de fipronil, para o controle da pulga Ctenocephalides felis felis em gatos. O experimento foi realizado no Laboratório de Quimioterapia Experimental em Parasitologia Veterinária do Departamento de Parasitologia Animal, Instituto de Veterinária, da Universidade Federal Rural do Rio de Janeiro. Foram empregados 18 gatos, sem raça definida, divididos em três grupos de seis. Um grupo permaneceu sem tratamento (controle), e os demais foram medicados com uma formulação referência do mercado veterinário ou com uma nova formulação em teste. Os animais tratados receberam 0,5 mL do produto ao longo da região dorso-cervical e foram infestados nos dias - 2, +5, +12, +19, +26 e +33. A primeira avaliação foi realizada quatro dias após a primeira infestação e, as demais, 48 horas após cada infestação, por meio do comb test. Ambas as formulações testadas foram eficazes até o dia +35 após o tratamento, não havendo diferenças entre seus níveis de eficácia ao longo do período experimental. A nova formulação, contendo fipronil a 10 por cento, apresentou a eficácia desejada no controle de C. f. felis em gatos.

The goal of the present study was to evaluate the comparative efficacy of two topical formulations containing 10 percent 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 percent 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 troughout the experimental period. The novel topical 10 percent fipronil formulation presented desirable efficacy on the control of C. f. felis on cats.

Otoacariasis due to Edentalges bradypus Fonseca 1954 (Acari; Psoroptidae) infestation in the brown-throated three-toed sloth Bradypus variegatus from Brazil.

The aim of this paper is to report the first description of gross pathological aspects of otoacariasis due to Edentalges bradypus Fonseca 1954 (Acari; Psoroptidae) infestation in the brown-throated three-toed sloth Bradypus variegatus Schinz, 1825 (Xenarthra; Bradypodidae) in Brazil. Mites were collected from massive skin crusts seen in both external ear canals and around both eyes of an extremely debilitated advanced-aged female sloth brought to the Wildlife Care Section of Universidade Estácio de Sá, Rio de Janeiro, Brazil.

Dioctophyme renale (Nematoda, Dioctophymatidae) infection in the crab-eating fox (Cerdocyon thous) from Brazil.

The purpose of this study is to report the first case of parasitism by the giant kidney worm, Dioctophyme renale (Goeze, 1782), in the crab-eating fox, Cerdocyon thous (Linnaeus, 1766), in Brazil. A debilitated adult male fox was taken to the Screening Center for Wild Animals in Rio de Janero (CETAS/RJ) and eventually died of an unknown cause. During necropsy, a brownish-red nematode, 28.9 cm long, was found in the peritoneal cavity. The worm was identified as a male D. renale. This study reports the first case of dioctophymatosis in the crab-eating fox, enlarging the range of wild definitive host species infected by the giant kidney worm in the Neotropical region.

Ocurrence of Philophthalmus gralli (Trematoda: Philophthalmidae) in farmed ostriches in Brazil.

This paper reports the occurrence of parasitism by the Oriental eye-fluke, Philophthalmus gralli in ostriches reared in a commercial flock from the State of Minas Gerais State, Southeastern Brazil. The two affected birds presented lacrimation, inflammatory reaction and loss of body condition. After physical examination the birds revealed, 17 and 15 trematodes each, only in the right eyes. The economic impact of this parasite on Brazilian ostrich industry is still undetermined, requiring further studies.