Cytological and parasitological analysis of bronchoalveolar lavage fluid for the diagnosis of Angiostrongylus vasorum infection in dogs.

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.

Larval output of infected and re-infected dogs with Angiostrongylus vasorum (Baillet, 1866) Kamensky, 1905.

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).

A method to obtain axenic Angiostrongylus vasorum first-stage larvae from dog feces.

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.