Alpha-chloralose Poisoning in 25 Cats: Clinical Picture and Evaluation of Treatment with Intravenous Lipid Emulsion

Objectives: The aims of this study were to describe the clinical picture and progression in cats with alpha-chloralose (AC) intoxication and to determine if treatment with intravenous (IV) lipid emulsion (ILE) influenced either the serum concentration of AC or the clinical signs.

Methods: Cats with suspected AC poisoning admitted to a university small animal hospital were included. The cats were randomised into two groups: one receiving 20% ILE at a dose of 300 mg/kg as a 2 min bolus, followed by a 1500 mg/kg continuous rate infusion over 30 mins (IL+ group) and the other receiving IV fluid therapy with Ringer's acetate (IL- group). Serum samples were drawn at 0, 2, 12 and 24 h after admission. Samples were tested for AC with a novel validated, quantitative, ultra-high-performance liquid chromatography-tandem mass spectrometry method. Vital and predefined clinical signs were noted at the times of sampling and patients were scored using a previously described intoxication severity score. Telephone interviews were conducted after discharge to assess outcome.

Results: A total of 25 cats were enrolled: 13 cats in the IL+ group and 12 in the IL- group. The most common clinical signs at presentation were tremor (n = 22, 88.0%), cranial nerve deficits (n = 20, 80.0%) and bradycardia (n = 19, 76.0%). No significant difference in AC concentration or change in intoxication score over time was found between the IL+ and IL- groups at any time point ( >0.05). All cats recovered within 72 h.

Conclusions And Relevance: ILE did not have any effect on the AC serum concentration or clinical signs in AC-poisoned cats. All cats survived until follow-up. In cats with an acute onset of the described neurological signs, AC intoxication is an important differential diagnosis with an excellent prognosis.