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American visceral leishmaniasis (VL) is a parasitic disease whose main domestic reservoir in the urban environment is dog and is considered one of the most important zoonoses in the context of public health. Serological tests are typically used for the diagnostic screening of the disease. This study aimed to analyse the performance of different methodologies used in the diagnosis of VL in dogs sampled from a recent transmission area. The sample consisted of 52 dogs separated into groups based on the absence and presence of clinical signs of VL. The following serological techniques were carried out: the DPP® rapid test (RT), the ALERE® RT and an RT and immunoenzymatic assay with a recently developed protein (rKDDR-plus). In addition, molecular techniques were carried out with conjunctival swabs, and bone marrow aspirate samples and parasitological samples were obtained directly from bone marrow aspirates. It was concluded that 27.4% of seronegative dogs were infected, but the serological tests, used as screening tests, showed unsatisfactory sensitivity results (average: 51.2%) for dogs without clinical signs. It was suggested that polymerase chain reaction with conjunctival swabbing be used as a screening test for dogs without clinical signs, as this is a non-invasive collection technique with high-sensitivity values.

A mongrel dog with angiostrongylosis died suddenly and was submitted to necropsy. Post-mortem findings showed adult worms in ectopic locations. This is the first report of Angiostrongylus vasorum adult worms being found within the pericardial sac and in the lumen of the bladder of an infected dog. A total of 587 A. vasorum first-stage larvae were recovered from different organs and tissues after concentration using Baermann apparatus.

An improved method to obtain a large number of axenic larvae of Angiostrongylus vasorum from fecal samples was developed in the present study. The procedure here in reported consisted of obtaining larvae using a modified Baermann technique, followed by an additional filtration step. This isolation technique recovered almost 90% of the living larvae in a clean preparation. Isolated larvae were submitted to decontamination treatments with either sodium hypochlorite or antibiotic cocktail solutions. The axenic status, as confirmed by oral inoculation of decontaminated larvae into germ-free mice, was only achieved using larvae treated with 0.5% sodium hypochlorite solution for 10 min. The isolation and decontamination treatment did not affect larval viability. Treated larvae remained viable and infective to the invertebrate host.

Fasciolosis is a parasitic disease which is caused by digenetic trematodes, such as Fasciola hepatica, and which occurs worldwide. The disease causes significant economic losses in cattle because of the reduction in milk and meat production and because the parasitized livers have no economic value. Also, abortion and mortality rates increase. To determine the occurrence and dispersal of F. hepatica in the state of Minas Gerais, fecal samples were collected from bovines aged 12 months and older between April 2005 and April 2006. The bovines came from 1,251 rural farms of 120 municipalities/cities in Minas Gerais. Water was collected to ascertain the presence of the intermediate host in the properties where infected bovines were found. A total of 16 municipalities had infected bovines and 13 had the presence of Lymnaea columella. We detected infected bovines in 70% of the rural farms visited in the municipality of Itajubá. Itajubá was also found to have infected snails with the larval stage of F. hepatica. The results revealed that infection by F. hepatica in bovines of Minas Gerais was associated with the presence of the intermediate host and favorable epidemiological factors, drawing attention to the necessity of adopting proper control measures in the area. A fasciolose é uma doença parasitária que ocorre em todo o mundo e é causada por um trematódeo digenético conhecido como Fasciola hepatica. A doença é responsável por causar perdas econômicas significativas em bovinos, devido à diminuição na produção de carne e leite, condenação de fígados parasitados e aumento na mortalidade. Para determinar a ocorrência e a dispersão da F. hepatica no estado de Minas Gerais, amostras de fezes de bovinos com idade superior a 12 meses foram coletadas, no período de Abril de 2005 a Abril de 2006. Foram examinados bovinos provenientes de 1.251 propriedades rurais de 120 municípios do estado de Minas Gerais. Coleções hídricas também foram examinadas, a fim de verificar a presença de hospedeiros intermediários nas propriedades onde foram encontrados bovinos parasitados. Para um total de 16 municípios foi relatada a presença de bovinos infectados por F. hepatica e destes, 13 apresentaram também o molusco Lymnaea columella. Foi possível diagnosticar bovinos infectados em 70% das propriedades visitadas no município de Itajubá. Além disso, no município de Itajubá foi possível detectar a presença de moluscos naturalmente infectados com diferentes estádios larvais de F. hepatica. Os resultados evidenciam a necessidade de medidas de controle para esta parasitose na área estudada, uma vez que foi possível verificar a presença de bovinos e moluscos infectados por F. hepatica, associada a fatores epidemiológicos favoráveis a dispersão do parasito.

Bronchoalveolar lavage (BAL) is a procedure that retrieves cells and other elements from the lungs for evaluation, which helps in the diagnosis of many pulmonary diseases. The aims of this work were to perform this procedure in dogs in the acute and chronic phases of an Angiostrongylus vasorum infection for cytological analysis and to evaluate the potential of this technique as a diagnostic method for this lung-heart worm. The BAL procedure was performed through the use of an endotracheal tube on seven A. vasorum infected dogs and on five non-infected dogs lined as a control group. Sixty days post-infection (dpi) active and live larvae were retrieved from the bronchoalveolar fluid (BALF) of all infected dogs. Furthermore, in one animal it was possible to retrieve larvae in its BALF before the pre-patent period. This work reports that the A. vasorum infection resulted in an increase of relative neutrophils and eosinophils counts. In contrast, there was a significant decrease in the alveolar macrophage relative count in infected animals from 60 to 330 dpi. This study shows that the BAL is an accurate technique for the diagnosis of canine angiostrongylosis. Moreover, the technique allows us to retrieve cells and other elements that line the lung surface for cytological evaluation, which provides information about inflammatory diseases, and the diagnosis and prognosis of pulmonary parasites such as A. vasorum.

Canine angiostrongylosis is a nematode infection in domestic dogs and wild canids. A natural infection in a domestic dog frequently leads to pneumonia, loss of physical performance, coughing, anemia, cardiac insufficiency, pulmonary fibrosis and death. The main diagnostic method is based on the finding of Angiostrongylus vasorum first-stage larvae (L1) in infected dog feces. With this objective, 11 experimentally exposed to 100 third-stage larvae (L3) per kilogram of body weight (mean = 885.45 L3/animal; S.E. = 77.7). The animals were monitored for 300 days post-single-infection (PI) and the quantity of L1 output measured. Our results showed an irregular excretion of L1 and a variation in the pre-patent period (33-76 days) and the number of L1 excreted by individual animals (1-1261 L1/g). After 300 days PI, five dogs were exposed a second time and monitored for 300 days post-re-infection (PRI) (=600 days PI). The quantity of L1 output demonstrated that double exposed dogs also presented an irregular excretion of L1 but a smaller variation in the number of L1 excreted by individual animals (4-550 L1/g).

Biomphalaria glabrata snails were experimentally infected with Angiostrongylus vasorum first-stage larvae and divided into four groups of 30 snails. To assess the shedding of third-stage larvae (L3), the snails were maintained under different stimuli: group 1 60 W light bulb for 24 h, group 2 37 degrees C water bath for 24 h, group 3 room temperature (23-25 degrees C) for 24 h, Group 4 room temperature (23-25 degrees C) for up to 15 days. After 24 h, a total of 512 A. vasorum L3, alive and active, were released by snails from group 1, while 2,446 L3 were released from group 2 and five L3 from group 3. After 15 days, snails from group 4 released a total of 44 L3. To evaluate the infectivity of A. vasorum L3, two mongrel dogs were successfully infected with L3 released by snails from groups 1 and 2, confirming that the infection of dogs with A. vasorum L3 was possible, independently of ingestion of the mollusk intermediate host. The results shown in these experiments suggest that angiostrongylosis could be directly transmitted to the definitive hosts, with implications for the parasite's life cycle.