What do lungworms look like?

• A. Cylindrical pale adult worms
• B. Small colourless spiral larvae
• C. Small dark round eggs
• D. Leaf-like segmented worms

Answer: (B)

Lungworms are nematodes, and in diagnostic samples the telling finding is the larval stage rather than adults or eggs. The small, colourless larvae you recover (often by Baermann technique) are the key clue. They are tiny, translucent, and move freely, sometimes described as having a slender, coiled or spiral appearance when observed under the microscope. This larval form is the typical diagnostic target because adults usually reside in the lungs and aren’t seen directly in feces or sputum, and eggs are not the usual finding for these infections in routine tests. The other descriptions describe organisms or stages that aren’t characteristic of lungworms in standard diagnostic materials: adults would be larger and not usually present in the sample you examine; dark round eggs aren’t the common diagnostic form for lungworms; leaf-like segmented worms would indicate a flatworm/tapeworm rather than a nematode.