Moxidectin intoxication in a dog — a patient care report

The patient presented as an emergency with an acute onset of tremors, ptyalism, visual impairment and disorientation; all of which started 24–36 hours prior to presentation.

On admission to the ward area, the patient was very disorientated, ambulatory but severely ataxic and salivating profusely. The physical examination revealed congested and tacky mucous membranes, pyrexia and tachycardia. The neurological examination revealed moderate tremors, severe ataxia, severe mental depression and hyperaesthesia.

The clinical history revealed that an accidental oral administration of the anti parasitic spot on treatment Advocate® (Bayer) had occurred 48 hours previously. The dog was given Advocate for large dogs which contains 250 mg of imidacloprid and 62.5 mg of moxidectin. The clinical signs and history were therefore suggestive of moxidectin intoxication. The same clinical signs were seen in a canine patient in a case report of accidental oral administration of Advocate reported in Australia (See et al, 2009). The active ingredients are imidacloprid and moxidectin which inhibit acetylcholine binding at the neuromuscular junction's post synaptic membrane and inhibit neurotransmission respectively (See et al, 2009).