Tick Paralysis in Australia: How POCUS Supports Safer Management

Scanning from caudodorsal to cranioventral, there is a clear progression of pathology: normal lung → increased B-lines → coalescing B-lines → shred sign.  Image acquired using a GE LOGIQ ultrasound system (Radincon).

Tick Paralysis and POCUS: Enhancing Patient Care

Snakes and spiders aren't the only deadly creatures we have in Australia. We also have the most venomous ticks. Respiratory failure remains the leading cause of death, driven by neuromusclar weakness and pulmonary complications such as pulmonary oedema and aspiration pneumonia. Point-of-care ultrasound (POCUS) supports real-time, cage-side decision-making that helps clinicians detect and manage complications early, without needing to move unstable patients.

1. Diagnose & Track Aspiration Pneumonia

Aspiration pneumonia is a common complication in severe tick paralysis and significantly worsens prognosis.

Lung POCUS enables cage-side detection of aspiration-related changes — typically in a cranioventral distribution — with findings that evolve with severity:

• Early: increased B-lines

• Intermediate: coalescing B-lines

• Advanced: shred/tissue signs and air bronchograms

POCUS can be repeated frequently to monitor disease progression. In dogs treated for aspiration pneumonia, lung pathology on ultrasound often mirror the clinical course, even when radiographs lag behind.

POCUS is especially helpful for assessing cranial ventral lung regions, a classic aspiration site often obscured on thoracic radiographs by the overlying heart (Rodrigues et al., 2022). Lung ultrasound may detect pathology within hours, whereas radiographic signs can take 24–48 hours to appear.

Ventilated patients:In mechanically ventilated dogs and cats with tick paralysis, maintain a high index of suspicion for bacterial pneumonia. As Tso et al. (2022) emphasize, clinicians should initiate empirical antimicrobials while awaiting culture results, then adjust treatment based on susceptibility to balance efficacy with antimicrobial stewardship.

2. Identify Gastric Distension & Aspiration Risk

Neuromuscular dysfunction in tick paralysis impairs:

• Airway protection

• Oesophageal motility

• Gastric emptying

This often results in fluid-filled, distended stomachs, increasing the risk of regurgitation and aspiration.

POCUS allows rapid cage-side evaluation of gastric contents and supports early interventions such as:

• Prokinetics

• Gastric decompression

• Patient positioning

These steps may reduce aspiration risk in high-risk patients.

3. Detect Pulmonary Oedema & Guide Fluids

Fluids should be administered with caution in tick paralysis due to the documented risk of pulmonary oedema and other lung complications, particularly in advanced cases (Webster et al., 2013).

Serial POCUS can:

• Detect pulmonary oedema early

• Monitor fluid status and help titrate fluid therapy

• Support decisions in patients with limited cardiopulmonary reserve

Bottom Line

POCUS brings imaging to the patient, reduces transport risk, and enables real-time monitoring in a condition defined by clinical progression.

It helps clinicians detect complications early, track response to therapy, and tailor interventions with confidence.

References

• Rodrigues NF et al. (2022). Lung ultrasound in dogs treated for aspiration pneumonia. J Vet Intern Med.

• Tso SSK et al. (2022). Airway cultures in mechanically ventilated dogs and cats with tick paralysis. Animals (Basel).

• Webster RA et al. (2013). Histopathological changes in lungs from dogs with tick paralysis. Aust Vet J.