Equine and companion animal lungworms Flashcards
Name the lungworm that affects horses
Dictyocaulus arnfieldi
Where are D.arnfieldi found? 4
- Adult worms in smaller bronchi –> frequent cause of chronic cough.
- Raised areas of over-inflated pulmonary tissue (surrounding small bronchus, containing worms and purulent exudate).
- Hyperplastic bronchial epithelium
- Peribronchial cuffing
Diagnosis - equine lungworm - 5
- CS
- Grazing Hx (donkeys!!)
- Faecal exam (only detects patent infections = small proportion of lungworm infections in horses).
- Tracheobronchial washings (large eosinophils)
- Response to anthelmintic treatment
How can you perform a faecal exam in the horse? 2
- Process immediately - McMaster method - embryonated egg
- Process later - Baerman technique - L1 larva and tail spine
Control - equine lungworm - 2
- don’t keep horses on pastures grazed by donkeys
- treat donkeys with appropriate anthelmintic in spring if grazed with horses (e.g. ivermectin)
What are the 2 more common species that cause canine lungworm?
- Angiostrongylus vasorum
- Filaroides (Oslerus) osleri
What is another name for Angiostrongulus vasorum?
French heartworm (adults reside in the right heart)
Outline the LC of A. vasourm
- lungworm of dogs/foxes
- typical metastrongyloid nematode:
- Indirect LC (mollusc IH)
- Adult worms (2cm, pulmonary arteries, RHS heart)
What are the 3 clinical forms/syndromes of A.vasorum?
- Cardio-respiratory signs
- Coagulopathies
- Neurological signs
Outline the cardio-respiratory signs of A.vasorum. Mechanism?
- chronic cough
- exercise intolerance (young)
HOW: BV blockage in PA (adult worms, eggs, larvae)
Outline coagulopathy signs of A. vasorum. Mechanism?
- SC haematomas
- internal haemorrhage
- prolonged bleeding from wounds
HOW: thrombocytopaenia, decreased CFs (5 and 8)
Outline the neuroligical signs of A.vasorum. Mechanism?
- depends on location of haemorrhage - paresis, behavioural changes, ataxia, loss of vision, seizures)
HOW: CNS haemorrhages
How can A.vasorum be diagnosed? 6
- CS
- Imaging
- Faecal exam (L1)
- Sputum exam (L1)
- Blood
- PME
What do you look for on radiographs if you suspect A. vasorum?
Peripheral lung lobe lesions - marked bronchial and peribronchial infiltrate
Outline faecal exam (Baerman) and sputum for L1 of A. vasorum
- larval recovery unreliable due to low numbers
- relatively long PPP (6-10 weeks)
- intermittent egg production by adults so collect samples on 3 consecutive days.
What might you seen on bloods with A.vasorum infection? 4
- Hypochromic anaemia
- Eosinophilia
- Coagulopathy tests (thromboplastin times)
- ELISA serology tests
What might you seen on PME with A.vasorum infection? 5
- adult worms
- lungs - mottled, reddish-purple
- SC haematoma
- Larger BVs (–> endarteritis –> fibrosis)
- RV (endocarditis - tricuspid valve)
How can A. vasorum be treated? 3
2 UK licensed anthelmintics for this:
- MOXIDECTIN (Advocate) - single dose, prevents infection for 1 months
- MILBEMYCIN (Milbemax) - weekly for 4 weeks
OFF-LABEL TREATMENT:
- Fenbendazole (Panacur) - daily for 1-3 weeks
OTHER:
- monitor course of treatment, repeat if necessary
- treat early in LC to minimise pathology
- supportive tx (fluids, O2, broncho-dilators, O2, ABs)
How can A.vasorum be controlled? 3
- Regular anthelmintics (risk based)
- IH control is impractical
- Public education
Outline the general LC for Filaroides (Oslerus) osleri
- dog lungworm
- ATYPICAL metastrongyloid nematode since it has a direct LC, adult worms live in tracheal nodules, transmission to puppies from bitch grooming (sputum)
- Clinical significance: asymptomatic –> chronic dry debilitating cough, associated with breeding kennels
How can Filaroides (Oslerus) osleri be diagnosed? 2
- Difficult
- Baerman to recover L1 from faeces (distinct dorsal indentation) but larvae sluggish, low numbers so few recovered
- Endoscopy - view tracheal nodules and confirm diagnosis.
How can F.osleri be treated?
Fenbendazole (Panacur) - licensed, 50mg/kg for 7 days
What does Aelurostrongylus abstrusus affect?
Lungworm of cats, generally uncommon
Outline the Aelurostrongylus abstrusus LC
- lungworm of cats, uncommon
- typical Metastrongyloid nematode - indirect LC (molluscan IH), adults worms live in lung parenchyma and small bronchioles)
- clinical significance - asymptomatic - serious respiratory problems
Outline pathogenesis of Aelurostrongylus abstrusus
often asymptomatic - severe respiratory problems (immuno-compromised cat, poor prognosis)
How can A.abstrusus be diagnosed? 3
- Faecal exam (Baerman - L1)
- PME - greenish nodules in lung
- Histopathology - differentiate from TB
How can A.abstrusus be treated?
Fenbendazole (Panacur) - licensed - 50mg/kg/day for 3 days)
What are other respiratory parasites of HORSES? 1, 1
- Parascarius equorum (migrating larvae)
- Echinococcus granulosus (hydatid cyst)
What are other respiratory parasites of DOGS? 2, 4
- Toxocara canis (migrating larvae)
- Toxascaris leonina (migrating larvae)
- Crenosoma vulpis (fox lungworm)
- Filaroides spp (parenchyma)
- Linguatula serrata (tongue worm)
- Pneomonyssus caninum (nasal mite)
What are other respiratory parasites of CATS? 2, 1
- Toxocara cati (migrating larvae)
- Toxascaris leonina (migrating larvae)
- Linguatula serrata (tongue worm)
