Outcome and medical management in dogs with lower motor neuron disease undergoing mechanical ventilation: 14 cases (2003-2009)

Abstract

Objective: To describe the application of intermittent positive pressure ventilation (IIPV) in dogs with lower motor neuron disease (LMND).

Design: Multi-institutional, retrospective study (2003-2009).

Setting: Intensive care units at multiple university teaching hospitals.

Animals: Fourteen dogs with LMND that underwent IIPV.

Interventions: None.

Measurements and main results: The ventilatory logs of 4 teaching hospitals were searched for dogs undergoing IIPV in association with a diagnosis of acute LMND. The medical records were evaluated for signalment, specific LMND, ventilatory management and duration, complications associated with ventilation, duration of hospitalization, and outcome. Descriptive statistics were used as indicated. Fifteen records were evaluated, 1 dog was excluded since it experienced cardiopulmonary arrest (CPA) before commencement of IIPV. The median age was 7.0 years (range 10 mo to 12 y). There were 5 Labrador retrievers, 4 mixed breeds, and 5 other breeds were each represented once. Five dogs were diagnosed with myasthenia gravis, 4 dogs with polyradiculoneuritis, and 5 dogs had an undetermined LMND. Clinical signs of weakness before ventilation were present for a median of 36 hours (range 6 h to 14 d). Dogs were ventilated for a median of 109 hours (range 5-261 h). Nine dogs had temporary tracheostomies performed, and 8 dogs received nutritional support. Five dogs developed ventilator associated pneumonia. Six dogs were successfully weaned from the ventilator with a median ventilatory time of 49 hours (range 25-192 h). Three dogs survived to discharge. No single LMND was associated with a better outcome.

Conclusions: High euthanasia rates and iatrogenic complications limit the ability to accurately prognosticate for affected dogs in this retrospective study, but in dogs with LMND that is severe enough to require IIPV, support may be required days to weeks.