Contributions to Knowledge of the Dictyocaulosis of the Red Deer

Dictyocaulosis is a parasitic disease affecting ungulate species, including red deer (Cervus elaphus). Dictyocaulus genus consist of nine species but only four are reported to infect red deer. The disease is characterized by respiratory tract infection, particularly in lungs, bronchi and bronchioles, causing inflammatory and hemorrhagic microscopic lesions but also emphysema and edema. Biological cycle consists of a female that oviposits larvae eggs in the bronchi and trachea to be expelled to the exterior by coughing and releasing the L1 in the environment. In this study 106 adult red deer were collected from seven locations in Extremadura (Spain). Eight positive lungs were primarily assessed by morphological identification, leading to a mean intensity of 13.25 adult worms/infected lung, but globally descending to an average of 1.78 adults/sampled lung. The presence of adult worms in the upper and middle respiratory tract was confirmed by anatomopathological analysis. Molecular identification was made by sequencing the COI gene. As a result, we have detected the presence of three genetic groups supported by significant subdivision using ɸST measure but D. cervi and D. viviparus showing its respective matrilineal ancestry while D. eckerti and D. cervi showing matrilineal sharing. Consequently, introgression between these two species was suggested. D. viviparus has been identified in the same Spanish region on the basis of morphological characters, but D. cervi and D. eckerti were reported for the first time in the explored geographic area.