Rusty's Battle With A Snake!

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This Case Chronicle details the clinical management of a dog by our Emergency and Critical Care (ECC) team, following a suspected Black Spitting Cobra envenomation event. It introduces the use of mechanical ventilation in such cases, a seldom-employed intervention in veterinary practice in our region. We aim to elucidate the clinical presentation, diagnostic workup, therapeutic interventions, and outcome, and we hope to provide valuable insights for veterinary practitioners encountering similar cases.

History and Signalment

Rusty is a 4-year-old male neutered canine that presented to the VES ECC department initially for a swollen limb and bilateral ocular discharge. As part of history-taking, the owner showed our ECC veterinarian a picture of a black snake in their garden, without evidence of a bite.

On examination, Rusty was bright/alert/responsive, able to ambulate with normal cardiorespiratory parameters. The major injuries that were noted were large amounts of mucoid discharge and a large corneal ulcer in one of his eyes, as well as a swollen antebrachium with no obvious bite marks.

Our initial diagnostics revealed the following:

  • CBC: Mild leucocytosis characterised by neutrophilia
  • PCV/TP: 41% / 7.0g/dL
  • Biochemistry: Mildly elevated globulins (4.7 g/dL)
  • Venous Blood Gas: Largely unremarkable
  • Coagulation Profile (PT/PTT): Within normal limits
  • CK: 991U/L (Normal range: 10 – 200 U/L)

Physical exam findings:

  • Large corneal ulcer and anterior uveitis
  • Swollen right antebrachium, no obvious bite marks or wounds


At this stage, we started the patient on eye medication and pain relief. As the signs were not clear if there was a bite and if antivenom was indicated, our team decided together with the client to monitor Rusty’s respiratory rate, effort, and general demeanour to decide if treatment for envenomation might be indicated at a later stage.

Further diagnostics

12 hours later, it appeared that Rusty’s condition had deteriorated. We proceeded to repeat the blood tests above and performed chest radiographs.

Before opening the diagnostic results, think about which test result changes would make us more suspicious of snake bite envenomation.

Click here for the updated diagnostics!
  • PCV/TP: 43% / 7.1g/dL
  • Biochemistry: Within normal limits
  • Venous Blood Gas: Mild metabolic acidosis and hyperventilation
  • Coagulation Profile (PT/APTT): Within normal limits
  • CK: 7398U/L
  • Chest radiographs: generalized alveolar pattern – non-cardiogenic pulmonary oedema


If you have answered changes in the chest radiographs and CK levels, you are absolutely right!

  • Elevated CK levels could signify myotoxic effects from snake bite envenomation, leading to muscle ischaemia and breakdown.
  • Non-cardiogenic pulmonary oedema could be a result of anaphylaxis from snake bite envenomation, or envenomation effects causing inflammation and oedema in the lungs.

All told, there was a strong suspicion for snake bite envenomation at this point, and antivenom was started. Given that Rusty was starting to show severe hypoxaemia despite oxygen supplementation, and heightened respiratory effort that was not sustainable, the decision was made to put Rusty on mechanical ventilation.

Mechanical Ventilation

LEARNING POINT #1: Indications for Mechanical Ventilation

While mechanical ventilation is a powerful tool, there is only a narrow window of indication for its usage in veterinary medicine, and these are:

  1. Severe hypoxaemia despite oxygen supplementation
  2. Severe hypoventilation despite therapy
  3. Excessive respiratory effort with impending respiratory fatigue or failure

As Rusty was showing indications for mechanical ventilation under points 1 and 3, the decision was made to place him on mechanical ventilation.

The goal of mechanical ventilation was to support his respiratory efforts, until he was sufficiently recovered from neurotoxicity to oxygenate independently.

Mechanical Ventilation and Nursing Care

Mechanical ventilation is a highly unnatural state for any patient to be in. As such, 24/7 intensive nursing care is required to reduce patient morbidity. In general, we will take one nurse off our ICU floor to exclusively manage a patient on the ventilator for their entire shift.

LEARNING POINT #2: Nursing care for patients on mechanical ventilation

This is a non-exhaustive list of nursing care we need to provide for an anaesthetised patient on the ventilator, which includes:

  • Airway Management: The ET tube needs to be managed in a sterile fashion, and needs to be suctioned and adjusted into a proper position regularly.
  • Oral Care: The patient’s mouth must be flushed and the pulse oximeter repositioned regularly to prevent the tongue from drying out.
  • Urinary Care: A patient under anaesthesia may not be able to void their bladder normally. This can be managed via constant manual expression, or a closed urinary catheterisation system.
  • Eye Care: Like any other patient under anaesthesia, the patient’s eyes need to be lubricated constantly to prevent ulceration. This is even more important in Rusty’s case given that he already has corneal ulcers.
  • GI Tract Care and Nutrition: Enteral nutrition is preferred in most cases to preserve GI health and ensure adequate nutrition. In Rusty’s case, a nasogastric tube was placed to ensure enteral nutrition could continue.
  • Recumbency Care: Recumbent patients are prone to pressure sores, muscle wastage and development of oedema. Rusty was kept on a well-padded bed, with passive range of motion and change in recumbency position performed every 4 hours.

Eventual Recovery

Rusty remained on mechanical ventilation for the next 4 days; ultimately, after a period of intensive care, we were able to successfully wean Rusty off mechanical ventilation.

His regular healthy appetite returned almost immediately, much to the delight of Rusty’s parents, and he was able to walk out of the hospital on his own four legs!

Mechanical ventilation in Singapore

VES Hospital is one of the few places in Singapore with a mechanical ventilator and a 24/7 ICU team capable of providing the necessary nursing care for patients on ventilators. Here are some of the conditions where mechanical ventilation can be indicated:

  • Acute Respiratory Distress Syndrome (ARDS)
  • Neuromuscular disorders affecting respiratory muscle function
  • Severe pulmonary oedema
  • Severe trauma or chest wall deformities
  • Drug toxicity causing respiratory depression of failure
  • Post-operative respiratory complications

If you have any patients that you think might require mechanical ventilation, please do not hesitate to call us and discuss with our ECC veterinarians!

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