case study
“Shake and Bake” – metaldehyde toxicity in a dog Ryan Philips, BVSc
Introduction
Poisoning of companion animals are commonplace in general practice. Often the clinical signs seen may not guide the clinician to any specific treatment option, and as a result a generic approach to toxin decontamination is taken (Tinson and Cook 2020). Since the toxin ingested is often not known, management and prognosis can be hard to define for the client. Many toxins affect the central nervous system with clinical signs ranging from mild ataxia to severe status epilepticus. Metaldehyde (the active ingredient in a variety of slug and snail bait products), is a toxin that can cause severe neurological signs. Together, these signs are often termed ‘shake and bake syndrome’ due to severe seizure and tremor-like activity and severe hyperthermia (Castle et al. 2017). This case report will describe the management and outcome of a case of metaldehyde toxicity in a dog, and some potential novel approaches to the treatment of this toxicity in a general practice setting.
Case history
A 2-year-old, neutered male Husky, weighing 40 kg, was presented for status epilepticus, severe muscle fasciculations and hypersalivation. Approximately 2 hours before arriving to the clinic, the owners believed the dog had eaten some type of toxin from their garage. Up until the incident the patient had no previous health concerns.
Clinical findings
The dog was carried into the treatment room and was able to hold himself in sternal recumbency. He was panting but thoracic auscultation was difficult due to the severe muscular fasciculations throughout his body. His pulse rate was 160, pulse quality was good, mucous membranes were pale pink and his capillary refill time was under one second. His rectal temperature was 39.5°C. The neurological exam revealed: bilateral miosis, the absence bilaterally of pupillary light reflexes, palpebral and menace responses. The patient also exhibited severe body tremors and hypersalivation, which transitioned to lateral recumbency and status epilepticus within 15 minutes Contact: Ryanp@vet111.co.nz
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Photo credit: Ryan Philips with permission of the owner
of presentation. Muscle fasciculations were observed over the entire body but were particularly severe in the hindlimbs and facial muscles. Tremors worsened when loud noises or any part of his body were touched indicating hyperaesthesia, this soon disappeared once the status epilepticus developed.
Initial management
The clinical findings were not specific for any particular toxin. As a result, a generic approach to treatment was undertaken to try and decontaminate the toxin from the dog. Clinical signs such as tremors, hypersalivation, hyperaesthesia and seizures were consistent with metaldehyde toxicity, whereas other clinical signs such as constricted pupils and the multiple cranial nerve deficits were not. Other differentials considered were organophosphate insecticide ingestion and trauma (Teichmann-Knorrn et al. 2020).
Companion Quarterly: Official Newsletter of the Companion Animal Veterinarians Branch of the NZVA | Volume 32 No 3 | September 2021
