Histopathological changes in the lungs from dogs with tick paralysis: 25 cases (2010-2012)

Objective To determine the prevalence and nature of histological lung lesions in dogs with tick paralysis. Methods A prospective study of 25 client-owned dogs that died during treatment for tick paralysis or were euthanased because of either the severity of the disease process or financial constraints was conducted at a veterinary emergency hospital in Queensland, Australia. Lung specimens were collected postmortem for histopathological examination. Results All 25 dogs had significant pulmonary changes: 9 exhibited congestion and alveolar oedema, with no obvious inflammatory cell infiltrate; 1 exhibited a mild increase in the number of alveolar macrophages in addition to congestion and alveolar oedema; the remaining 15 dogs had moderate or severe bronchopneumonia, with 2 showing evidence of aspiration pneumonia. Conclusion Dogs with clinically severe tick paralysis are likely to have pulmonary parenchymal disease. Bronchopneumonia may be present in a significant proportion of cases and may reflect aspiration.