Prevalência de ecto e endoparasitas em camundongos e ratos criados em biotério

Durante um período de 5 anos (1986-1991) foram examinados 229 camundongos e 128 ratos, de ambos os sexos, com idade entre 1 a 2 meses, provenientes de 4 biotérios convencionais (2 de camundongos e 2 de ratos), e de um biotério provido de barreiras sanitárias (camundongos controle). A amostragem semestral aleatória consistiu em 5% da população das salas com mais de 100 animais cada. No exame clínico geral observaram-se distensão abdominal e diarréia nos camundongos e ratos dos biotérios convencionais, o que não foi constatado nos animais do biotério controle. Discreta alopecia e pêlos eriçados foram detectados em todos os animais das colônias estudadas. Infestações porMyobia musculi, Myocoptes musculinus, Radfordia affinis, Radfordia ensiferae Poliplax spinulosa foram identificadas nas colônias convencionais, em infestações múltiplas ou simples. Myobia musculiioi descrito pela primeira vez em ratos criados em biotérios. Infecções por endoparasitas  Hymenolepis nana, Syphacia sp, Aspiculuris tetraptera, Trichomonas muris, Spironucleus muris, Giardia muris e Eimeria sp foram observadas nas colônias convencionais. Entretanto, através dos resultados da necrôpsia, na colônia controle de camundongos somente foram  encontrados Syphacia sp e Aspiculuris tetraptera. A necrôpsia confirmou que o uso do método de anal-swab para detecção de ovos de Syphacia sp é preferível ao de Willis, e revelou o grau de infecção de protozoários intestinais. Syphacia sp, Hymenolepis nana e Aspiculuris tetraptera foram eficientemente detectados pelo método de Willis.During five years (1986-1991), 229 mice and 128 rafs of both sexes, aged 01 to 02 months, from different breeding colonies in the city of São Paulo, Brazil, were examined for parasitological control. Four conventional colonies (2 of rats and 2 of mice) and one mice barrier colony (control) were analyzed. Semi-annual sampling made use of 5% of the animals in the rooms. The population of each room comprised over 100 animals. In the general examination, abdominal distention and diarrhea wereobserved in the mice and rats from conventional colonies, but not in animals from the control colony. Mild alopecia and bristly hairs were detected in all animals from the evaluated colonies. Ectoparasites such as Myobia musculi, Myocoptes musculinus, Radfordia affinis, R. ensifera and Poliplax spinulosa were identified in the conventional colonies, in multiple and single infestations. Myobia musculi is described for the first time in rats reared in breeding colonies. Endoparasites such as Hymenolepisnana, Syphacia sp, Aspiculuris tetraptera, Tritrichomonas muris, Spironucleusmuris, Giardia muris, and Eimeria sp were observed in the conventional colonies. However, through necropsy results, in the control colony Syphacia sp and Aspiculuris tetraptera were the only parasites found. Necropsy confirmed the indication of the anal swab method for detection of Syphacia sp rather than the Willis method, and revealed the degree of infection by intestinal protozoa and Syphacia sp. H. nana and Aspiculuris tetraptera were efficiently detected by Willis method

Effects of Fire on the Ectoparasites of Small Mammals in Longleaf Pine (Pinus Palustris) Habitats

I tested the hypothesis that fire significantly decreases prevalence and abundance of ectoparasites and therefore increases the condition of small mammals in longleaf pine habitats. I trapped two areas with paired burned and unburned sites in east central Georgia during 2002 2003. I collected 190 mammals from 9 species and recovered 32 ectoparasite species. I found little overlap in mammal species between paired sites. The overall chance for any mammal of having an ectoparasite was significantly greater on unburned sites (87.7% prevalence on burned vs. 100% unburned). There was no significant relationship between the number of individual ectoparasites on a mammal and its condition. Although I provide some evidence that fire can affect ectoparasite abundance, the pattern varied by site and was not consistent for all species. Several new host ectoparasite associations were recorded

Incidence of Chirodiscoides caviae in Laboratory Rats-Screening, Identification and Treatment

This is a report on the incidence and treatment of the guinea pig fur mite Chirodiscoides caviae, which  was so far considered as host specific, in a conventional colony of laboratory rats. Chirodiscoides caviae  infestation in laboratory rats was accidentally observed during the screening of Syphacia obvelata by the  peri-anal cellophane tape test (CTT). The organism was identified by comparing the morphology described  by various researchers and was differentially diagnosed from other common mites of rat, Radfordia ensifera  and Notoedres muris. The adult male mites (n=15) were of 330.2±13.3 μm long and the females (n=15)  495.5±25.2 μm. Later on, the entire rat colony consisting of Wistar, Sprague Dawley and Spontaneously  Hypertensive Rats (SHR) and the mice colony of Balb/c and Swiss Albino were randomly sampled and  screened for the presence of the mite by the cellophane tape technique. All the rat strains were found positive  for C. caviae infestation, which was more concentrated towards the posterior region of the body and,  collectively, the screening results of C. caviae revealed that the posterio-dorsal and peri-anal regions are  most suitable for sampling-suggesting that, the infestation pattern of C. caviae in rats has similarities to that  of guinea pigs. Interestingly the mice colony was found free from the infestation. The Cellophane tape test was found to be an easier method than fur examination by hair plucking and equally  accurate for screening of fur mite in a colony of laboratory rats. No clinical symptoms were observed in  any of the animals in the colony, which possessed infestation. The facility strictly practised physical separation  of animals by species, which pointed to the only possibility of cross infestation being through indirect  contact between guinea pigs and laboratory rats and thereby questioning previous reports on the mode of  transmission of C. caviae. The entire colony was effectively treated with 0.2% Ivermectin spray followed by  1% spray in an interval of 2 weeks. This report is the first one, which demonstrates the guinea pig fur mite  in laboratory rats. It also questions the so far documented “host specificity” and “direct contact” mode of  transmission and demonstrates indirect contact as a possible mode of transmission.

Efficacy and safety of topical eprinomectin to control Myocoptes musculinus infestation in mice.

Myocoptes musculinus is the most common fur mite identified among laboratory mice; infested mice, in addition to dermatological signs, may also be prone to secondary infections, affecting the outcome of a research trial. This trial was conducted in order to assess the safety and efficacy of a single topical administration of eprinomectin (5mg/kg BW) in a naturally infested laboratory mice colony. A safety trial was conducted on 20 uninfested pregnant females assigned to two groups, receiving eprinomectin and mineral oil, respectively. The mice were examined daily for signs of illness or toxicity; nests were individually weighted at 21 and 28 days postpartum. No acute toxicity was observed, all treated females gave full term delivery and number and mean weight of newborns ranged in the physiological values. To evaluate the efficacy, 20 naturally infested non-pregnant females were divided into two groups, treated as in the safety trial. Animals were observed daily for 15 min until 21 days post-treatment (DPT) and a “pruritus index” (PI: scratching and gnawing acts/mouse/min) was calculated. Pelage examination was performed on DPT 7, 14, 21 and 50. The “PI” was significantly lower in the treated group and mites were eradicated from all infested animals. A single topical administration of eprinomectin at a (high) dosage of 5mg/kg BW was safe and effective to control M. musculinusin mice

Ectoparasites and Other Arthropod Associates of Some Voles and Shrews From the Catskill Mountains of New York

Reported here from the Catskill Mountains of New York are 30 ectoparasites and other associates from 39 smoky shrews, Sorex fumeus, 17 from 11 masked shrews, Sorex cinereus, 11 from eight long-tailed shrews, Sorex dispar, and 31 from 44 rock voles, Microtus chrotorrhinus

Interpreting Neuroendocrine Hormones, Corticosterone, and Blood Glucose to Assess the Wellbeing of Anesthetized Rats during Euthanasia

Current recommendations for assessing animal wellbeing during euthanasia suggest that measuring neuroendocrine hormones-such as ACTH, noradrenaline, and adrenaline-is preferable to measuring corticosterone and blood glucose because of the sensitivity of neuroendocrine hormones to the acute stress associated with rapid methods of euthanasia. However, theseneuroendocrine hormones can be stimulated in ways that confound interpretation of welfare assessment in euthanasia studies.Although this property does not negate the usefulness of neuroendocrine hormones as tools of assessment, it is importantto differentiate the stress associated with the induction of anesthesia before the loss of consciousness (an animal wellbeingconcern) with the physiologic responses that occur after the loss of consciousness (not an animal wellbeing concern). In thisstudy, rats were anesthetized by using a ketamine-xylazine combination. Once the rats achieved a surgical plane of anesthesia,they were exposed to O2, CO2, or isoflurane, followed by terminal blood collection to assess concentrations of ACTH,noradrenaline, corticosterone, and blood glucose. Compared with animals exposed to O2 or isoflurane, rats exposed to CO2had significant increases in their serum concentrations of ACTH and noradrenaline, but blood glucose and corticosteronedid not differ between groups. These findings indicate that noradrenaline and ACTH should be used with caution to assessanimal wellbeing when the method of euthanasia might confound that assessment

Ectoparasite burdens of the Damaraland mole-rat (Fukomys damarensis) from Southern Africa

Damaraland mole-rats (Fukomys damarensis) of the family Bathyergidae are widely distributed subterranean rodents in sub-Saharan Africa. No parasites have ever been reported for this species and only 1 ectoparasite is described for the entire genus. In the current study ectoparasites were collected from individuals captured at 3 localities in South Africa and Namibia to document the ectoparasite community of F. damarensis, investigate their aggregation patterns and evaluate the influence of season on ectoparasite burden. A total of 2,071 arthropods from 9 mite taxa and 1 louse species (Eulinognathus hilli) were collected from 293 hosts sampled. Of these 5 mite species (Androlaelaps scapularis, A. capensis, A. tauffliebi, Radfordia sp. and unidentified chiggers) and the louse were parasites while the remainder were soil mites. All ectoparasites were highly aggregated and the species richness as well as the prevalence and abundance of 4 of them were significantly greater in summer compared to winter, possibly as a result of seasonal changes in rainfall patterns affecting the ectoparasites and/or host behavior.NRF-SARChI chair for Mammalian Behavioural Ecology and Physiology, the NRF and the University of Pretoria.http://digitalcommons.unl.edu/jrnlparasitologyhb201

Infecciones mixtas por ectoparásitos y endoparásitos en ratones y ratas de laboratorio

Se ha determinado la presencia de parasitosis mixtas en ratones y ratas del Bioterio Central de la Universidad Centroccidental Lisandro Alvarado (UCLA), y la correlación entre ellas, seleccionando 10 animales por sexo, edad (3, 5, 7, 9 y 14 semanas), y cepa de ratón (NMRI, C57Bl/6, Balb/c), y rata (Sprague Dawley y SHR/N) para un total de 500 animales según recomendaciones de Thursfield, (1990). Las muestras se han obtenido por duplicado en vivo y en necropsia de: heces (Examen directo y Mc Master), piel (cuello, dorso-lumbar y ano) con la técnica de celofán; sangre, corazón, pulmón, hígado, bazo, riñones, estómago e intestino (duodeno, yeyuno-íleon y ciego), en frotis teñidos con el método de Giemsa. Se ha determinado la frecuencia de infecciones mixtas y la correlación entre las parasitosis mediante análisis de correlación de Spearman. Las especies identificadas han sido: Myocoptes musculinus, Giardia muris, Trichomona muris, Spironucleus muris, Syphacia obvelata y Apicularis tetraptera en los ratones , y Spironucleus muris solo en NMRI de 6 semanas. En las ratas se ha identificado Radfordia affinis, Giardia muris, Trichomona muris y Syphacia muris. Existe correlación positiva de A. tetraptera con G. muris en ciego (r=0, 492; P<0, 01) y T. muris en duodeno (r=0, 362; P<0, 01). En NMRI casi el 100% están parasitados por al menos 4 especies principalmente machos, éste comportamiento es similar en C57Bl/6 pero con prevalencias inferiores y en los Balb/c predominan 2 ( M. musculinus y G. muris) o 3 especies (M. musculinus , G. muris y T. muris). En ratas se producen infecciones mixtas (99, 9%) por 2-5 especies parásitas. Los flagelados son los más comunes, asociados a S. obvelata o A. tetraptera en ratones, o S. muris en ratas, sumando la presencia de M. musculinus y R. affinis respectivamente. The occurrence of mixed parasitic infections was analyzed in laboratory mice and rats. The study was conducted in 500 animals randomly selected in the vivarium at the Universidad Centro-occidental Lisandro Alvarado (Barquisimeto, Venezuela). A total of 10 animals for each sex (male versus female), age group (3, 5, 7, 9 y 14 weeks) and strain of mice (NMRI, C57Bl/6 and Balb/c) and rats (Sprague Dawley and SHR/N) was selected. Duplicate samples were taken from various locations and analyzed by different methods, including the McMaster technique for faecal egg counting, the cellophane tape technique for skin samples (neck, back, lumbar and anus), and Giemsastaining for smears of different tissues (blood, heart, lung, liver, spleen, kidneys, stomach, duodenum, jejunum, ileum and caecum). Various parasites were identified in mice (Myocoptes musculinus, Giardia muris, Trichomona muris, Spironucleus muris, Syphacia obvelata y Apicularis tetraptera) and rats (Radfordia affinis, Giardia muris, Trichomona muris y Syphacia muris). Spironucleus muris was only identified in NMRI mice aged six weeks. The coefficient of ranks of Spearman revealed a positive correlation between A. tetraptera and G. muris in the caecum (r=0.492; P<0.01), or T. muris in the duodenum (r=0.362; P<0.01). Mixed infections with four species were seen in most NMRI and C57Bl/6 male mice. Mixed infections with two (M. musculinus and G. muris) o three species (M. musculinus, G. muris and T. muris) predominated in Balb/c mice. Mixed infections with two-to-five species were seen in most rats. Flagellate protozoa were the most prevalent parasites in both mice and rats, followed by S. obvelata and A. tetraptera (mice) or S. muris (rats)

Estudo de ectoparasitas no porquinho-da-Índia e noutros pequenos roedores domésticos

Dissertação de Mestrado Integrado em Medicina VeterináriaOs pequenos roedores são animais cada vez mais escolhidos como animais de estimação um pouco por todo o mundo, sendo muitos deles também utilizados em investigações médicas e laboratoriais. Estes animais são, por vezes, hospedeiros de ectoparasitas, alguns deles com potencial zoonótico. Contudo, em Portugal, pouco se sabe sobre as prevalências destes parasitas nos roedores domésticos e sobre o seu potencial impacto na saúde pública. Este estudo teve como objetivo avaliar a prevalência dos ectoparasitas considerados mais comuns nos pequenos roedores domésticos em Portugal, em particular na região de Lisboa. Foram recolhidos ao nível da clínica, um total de 44 casos suspeitos de presença de ectoparasitas (34 foram recolhidos dos arquivos da clínica e os restantes 10 foram recolhidos durante o período de seis meses de estágio), estando estes distribuídos por 38 porquinhos-da-Índia, quatro murídeos (duas ratazanas e dois ratos), um cricetídeo (um hamster dourado) e uma chinchila. Os animais foram posteriormente analisados através de técnicas de exame direto do pêlo, recolha do mesmo e tricograma, raspagens superficial e profunda da pele, teste da fita adesiva e observação ao microscópio ótico. Procedeu-se ainda à análise estatística descritiva dos dados obtidos. Os porquinhos-da-Índia (n=38) foram positivos a Trixacarus caviae (52,6%), Chirodiscoides caviae (21,1%), Demodex caviae (2,6%), Notoedres muris (2,6%), Psoroptes cuniculi (2,6%), Sarcoptes scabiei (2,6%), Gliricola porcelli (13,2%) e Gyropus ovalis (2,6%). Os murídeos (n=4) foram positivos a Trixacarus caviae (50%) e Myocoptes musculinus (50%). A chinchila (n=1) foi positiva a Trixacarus caviae e o cricetídeo (n=1) foi positivo a Demodex aurati. Dos 44 animais examinados, 23 (52,3%) denotaram a presença do ácaro Trixacarus caviae, oito (18,2%) do ácaro Chirodiscoides caviae, um (2,3%) do ácaro Demodex caviae, um (2,3%) do Demodex aurati, um (2,3%) do ácaro Notoedres muris, dois (4,5%) do ácaro Myocoptes musculinus, um (2,3%) do ácaro Psoroptes cuniculi, um (2,3%) do ácaro Sarcoptes scabiei, cinco (11,4%) do piolho Gliricola porcelli e um (2,3%) do piolho Gyropus ovalis. Verificou-se que em porquinhos-da-Índia a prevalência de piolhos (15,8%) é bastante inferior à de ácaros (84,2%), sendo Gliricola porcelli e Trixacarus caviae, o piolho e ácaro, respetivamente, mais prevalentes nos pequenos roedores domésticos da amostra.ABSTRACT - STUDY OF ECTOPARASITES IN GUINEA PIGS AND OTHER DOMESTIC SMALL RODENTS - Nowadays, small rodents are becoming more popular around the world as house pets and some of them are vastly used in laboratorial and medical research. These animals are sometimes hosts of ectoparasites, some of them with zoonotic potencial. However, in Portugal little is known about the prevalence of ectoparasites in small pet rodents, and about their potencial impact in public health. Therefore, the main objective of this study was to evaluate the prevalence of the most common ectoparasites in small pet rodents in Portugal, in particular in the Lisbon district. A total of 44 samples from animal suspected of being infested with ectoparasites, were gathered at the practise (34 animals were collected from the clinic arquives and the other 10 were gathered during the six months of internship). 38 of them were guinea pigs, four were murids (two rats and two mice), one cricetid (one golden hamster) and one chinchilla. These animals were later analysed through dermatological techniques, such as direct observation of the fur, trichogram, superficial and deep skin scrapings, adhesive tape test and observation of the gathered samples under light microscope. A descriptive statistical analysis was performed with the gathered data. Guinea pigs (n=38) were positive to Trixacarus caviae (52,6%), Chirodiscoides caviae (21,1%), Demodex caviae (2,6%), Notoedres muris (2,6%), Psoroptes cuniculi (2,6%), Sarcoptes scabiei (2,6%), Gliricola porcelli (13,2%) and Gyropus ovalis (2,6%). The murids (n=4) were positive to Trixacarus caviae and Myocoptes musculinus. The chinchilla (n=1) was positive to Trixacarus caviae and the cricetid (n=1) was positive to Demodex aurati. Out of the 44 examined animals, 23 (52,3%) were infested with the mite Trixacarus caviae, eight (18,2%) with the mite Chirodiscoides caviae, one (2,3%) with the mite Demodex caviae, one (2,3%) with the mite Demodex aurati, one (2,3%) with the mite Notoedres muris, two (4,5%) with the mite Myocoptes musculinus, one (2,3%) with the mite Psoroptes cuniculi, one (2,3%) with the mite Sarcoptes scabiei, five (11,4%) with the lice Gliricola porcelli and one (2,3%) with the lice Gyropus ovalis. It was verified that in guinea pigs the lice prevalence (15,8%) is much lower than the mite prevalence (84,2%), and that the most prevalent lice is Gliricola porcelli and the most prevalent mite is Trixacarus caviae

Ivermectina no tratamento de camundongos (Mus muscullus) infestados por ácaros

A utilização de animais de laboratório em pesquisa é uma prática comumente empregada, porém estes estudos podem ser afetados pelas condições ambientais e infecciosas. Este estudo visou relatar a infestação mista por ectoparasitos em camundongos (  Mus muscullus) mantidos em um biotério experimental e testar um protocolo terapêutico no controle dos parasitos. Em 20 animais foi observado pelo seco, áreas de alopecia com lesões avermelhadas e úmidas, prurido intenso e crostas na região dorsal do corpo. Dos camundongos avaliados, foi coletado pelo e realizado raspado cutâneo para análise microscópica, onde se identificou nesses roedores ácaros das espécies Radfordia affinis, Myocoptes musculinus e Demodex sp. Os roedores foram separados em dois grupos, sendo que os animais do grupo A foram tratados com ivermectina 1% diluída em água na dose de 0,007 mg.ml-1 por cinco dias consecutivos e os do grupo B não foram tratados. Após 10 dias do início do tratamento, no grupo A não foram encontrados ácaros, já no grupo B o número de ectoparasitos e as lesões de pele aumentaram. Portanto, conclui-se que a terapia utilizada apresenta eficácia nos controle de infestações por estes ácaros