Vetdle Archive
Archive Case #203: Feline Lungworm Infection
Cat veterinary case - Easy - September 22, 2026
Clinical Clues
- Miso, a two-year-old cat, keeps crouching for what her owner calls “hairballs”—but nothing comes up.
- A phone video shows coughing. Miso hunts mice outdoors and now tires sooner during play.
- Chest radiographs show bronchial and small nodular interstitial changes, compatible with several lower-airway diseases.
- Routine faecal flotation was negative, but a fresh sample examined using the Baermann larval-recovery technique contains nematode larvae.
- The recovered first-stage larvae have a wavy tail with a spine.
- Species-specific PCR identifies Aelurostrongylus abstrusus, confirming a parasitic infection of the lungs.
Diagnosis
Feline Lungworm Infection
Miso’s cough could initially resemble asthma. The hunting history raises suspicion, but the recovered larvae and PCR establish the cause. Imaging alone would not reliably separate these conditions. Remember: Choose the right parasite test: a negative routine flotation does not rule out lungworm. Baermann testing is designed to recover larvae.
Learning review
Review the case evidence
Use the paired clues to explain how the evidence in this cat case supports the provided diagnosis, Feline Lungworm Infection, then compare your reasoning with the case explanation.
Evidence checkpoints
Clues 1-2
- Clue 1: Miso, a two-year-old cat, keeps crouching for what her owner calls “hairballs”—but nothing comes up.
- Clue 2: A phone video shows coughing. Miso hunts mice outdoors and now tires sooner during play.
Clues 3-4
- Clue 3: Chest radiographs show bronchial and small nodular interstitial changes, compatible with several lower-airway diseases.
- Clue 4: Routine faecal flotation was negative, but a fresh sample examined using the Baermann larval-recovery technique contains nematode larvae.
Clues 5-6
- Clue 5: The recovered first-stage larvae have a wavy tail with a spine.
- Clue 6: Species-specific PCR identifies Aelurostrongylus abstrusus, confirming a parasitic infection of the lungs.
Self-review prompts
- After clues 1-2, what evidence from this cat case shaped your initial interpretation?
- When you compare clues 3-4 with clues 1-2, what changed in your reasoning about Feline Lungworm Infection?
- How do clues 5-6 align with the case explanation for Feline Lungworm Infection?
Educational Use
Vetdle archive cases are educational veterinary games for diagnostic reasoning practice. They do not provide veterinary advice, diagnosis, treatment, or professional medical guidance.