The parasite whose larvae enter the nasal cavity of sheep is which species?

The parasite whose larvae enter the nasal cavity of sheep is which species?

• A. Gasterophilus species
• B. Hypoderma species
• C. Oestrus species
• D. Cuterebra species

Answer: (C)

Larvae entering the nasal cavity of sheep point to the nasal bot fly, Oestrus ovis. This species specifically targets sheep and goats, with adult flies laying eggs around the nostrils. The hatched larvae migrate into the nasal passages and sinuses, causing irritation and nasal discharge. The other options describe parasites with different primary habitats or hosts: Gasterophilus species infest horses and develop in the stomach; Hypoderma species form subcutaneous warbles in cattle; Cuterebra species usually affect rodents and sometimes dogs or cats, migrating through subcutaneous tissues rather than the nasal cavity of sheep.

Larvae entering the nasal cavity of sheep point to the nasal bot fly, Oestrus ovis. This species specifically targets sheep and goats, with adult flies laying eggs around the nostrils. The hatched larvae migrate into the nasal passages and sinuses, causing irritation and nasal discharge. The other options describe parasites with different primary habitats or hosts: Gasterophilus species infest horses and develop in the stomach; Hypoderma species form subcutaneous warbles in cattle; Cuterebra species usually affect rodents and sometimes dogs or cats, migrating through subcutaneous tissues rather than the nasal cavity of sheep.