Angiostrongylus vasorum in dogs: diagnosis and coagulopathy
14-month-old Beagle living in a house with a garden in a humid area, which often eats snails. Cough for a month, scleral haemorrhage and a large haematoma after a vaccination. Thoracic radiographs show a multifocal peripheral interstitial-alveolar pattern.
| Parameter | Result | Reference |
|---|---|---|
| Platelets | 190,000/µL | 200,000–500,000 |
| Prothrombin time (PT) | 11 s | 6–10 |
| aPTT | 22 s | 10–17 |
| Fibrinogen | 80 mg/dL | 150–400 |
Which combination of tests is most useful to confirm the suspicion?
chevron_right Show answer and explanation
A. Knott test and Dirofilaria immitis antigen test
These detect heartworm, which also causes cough, but not Angiostrongylus. Angiostrongylus larvae are shed in faeces and do not circulate in blood as microfilariae.
B. Rapid A. vasorum blood antigen test and Baermann technique on faeces from three days
Correct. The in-clinic antigen test has good specificity and gives an immediate result. Baermann detects L1 larvae and uses faeces from three consecutive days because shedding is intermittent.
C. A single conventional faecal flotation
L1 larvae are poorly detected or distorted by flotation and shedding is intermittent: a negative result does not rule out infection.
D. Treat with vitamin K1 and repeat coagulation, because it is rodenticide poisoning
Rodenticides mainly prolong PT without hypofibrinogenaemia or weeks of respiratory signs. The picture (cough, lung pattern, young dog eating snails) points to Angiostrongylus.
lightbulb Key takeaway
Think of Angiostrongylus in a young dog with cough, unexplained bleeding or neurological signs from haemorrhage. Intermediate hosts are slugs and snails (frogs can act as paratenic hosts). It is treated with macrocyclic lactones (moxidectin or milbemycin oxime) or fenbendazole, and monthly prevention reduces risk in areas with cases.
Test yourself with 10 random questions
Cardiology · 100 questions, a different test every time
Related questions
Updated: October 31, 2026 · Educational content for veterinary professionals. It does not replace current clinical guidelines or the judgement of the attending veterinarian.