First Report of Bronchial Oestriasis in a Domestic Dog

Abstract

This study reports the first case of bronchial myiasis in a dog caused by Oestrus ovis, a parasite known to infest sheep, and occasionally other mammals. A 9-year-old dog, from a rural area near Ancona (Italy), exhibited persistent coughing despite antibiotic and anti-inflammatory treatments. Bronchoscopy revealed a live first-instar larva of O. ovis, confirmed through morphological and molecular analyses. Larval removal and treatment with isoxazolines resulted in a rapid resolution of symptoms. This case highlights the critical importance of including atypical parasitic infestations in the differential diagnosis of respiratory symptoms in dogs. It underscores the importance of heightened vigilance, particularly in areas with sheep flocks, to prevent and manage such infestation effectively.

Keywords: Oestrus ovis; bronchoscopy; dog; first instar larva; myiasis.

FIGURE 1

Oestrus ovis first instar collected from the dog after bronchoscopy: (a) total body (× 100); (b) anterior end with cephaloskeleton (× 200); (c) detail of the posterior end, partially lateral view (× 400); (d) detail of the posterior end after full clarification, with nine hooks on each side: ventral view (× 400).

FIGURE 2

Neighbour‐Joining phylogenetic tree based on the p‐distance model. The tree is drawn to scale, with branch lengths measured in the number of substitutions per site. The analysis involved 19 nucleotide sequences. There were 644 positions in the final dataset.