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. 2022 Sep 5;18(1):334.
doi: 10.1186/s12917-022-03370-w.

Alpha-chloralose poisoning in cats in three Nordic countries - the importance of secondary poisoning

Ulrika Windahl  1 , Annica Tevell Åberg  2   3 , Fedor Kryuchkov  4 , Sandra Lundgren  5 , Cecilia Tegner  5 , Kristoffer Dreimanis  5 , Sanna Koivisto  6 , Outi Simola  7 , Morten Sandvik  4 , Aksel Bernhoft  4
Affiliations

Alpha-chloralose poisoning in cats in three Nordic countries - the importance of secondary poisoning

Ulrika Windahl et al. BMC Vet Res. .

Abstract

Background: Alpha-chloralose (AC) is a compound known to be toxic to various animal species and humans. In 2018 and 2019 an increase in suspected cases of AC poisoning in cats related to the use of AC as a rodenticide was reported to national veterinary and chemical authorities in Finland, Norway and Sweden by veterinarians working in clinical practices in respective country. The aims of this study were to prospectively investigate AC poisoning in cats, including possible secondary poisoning by consuming poisoned mice, and to study metabolism and excretion of AC in cats through analysis of feline urine.

Methods: Data on signalment, history and clinical findings were prospectively collected in Finland, Norway and Sweden from July 2020 until March of 2021 using a questionnaire which the attending veterinarian completed and submitted together with a serum sample collected from suspected feline cases of AC-poisoning. The diagnosis was confirmed by quantification of AC in serum samples. Content of AC was studied in four feline urine samples, including screening for AC metabolites by UHPLC-HRMS/MS. Bait intake and amount of AC consumed by mice was observed in wild mice during an extermination of a rodent infestation.

Results: In total, 59 of 70 collected questionnaires and accompanying serum samples were included, with 127 to 70 100 ng/mL AC detected in the serum. Several tentative AC-metabolites were detected in the analysed feline urine samples, including dechlorinated and oxidated AC, several sulfate conjugates, and one glucuronic acid conjugate of AC. The calculated amount of AC ingested by each mouse was 33 to 106 mg with a mean of 61 mg.

Conclusions: Clinical recognition of symptoms of AC poisoning in otherwise healthy cats roaming free outdoors and known to be rodent hunters strongly correlated with confirmation of the diagnosis through toxicological analyses of serum samples. The collected feline exposure data regarding AC show together with the calculation of the intake of bait and subsequent AC concentrations in mice that secondary poisoning from ingestion of mice is possible. The results of the screening for AC metabolites in feline urine confirm that cats excrete AC both unchanged and metabolized through dechlorination, oxidation, glucuronidation and sulfatation pathways.

Keywords: Alpha-chloralose; Cat; Chloralose; Feline; Metabolism; Mice; Poisoning; Secondary; Toxicosis.

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Conflict of interest statement

The authors declare to have no competing interests.

Figures

Fig. 1
Fig. 1
The geographical distribution of the in total 59 included cases
Fig. 2
Fig. 2
Alpha-chloralose concentration in 59 serum samples from cats with suspected AC-poisoning collected in Finland, Sweden, and Norway
Fig. 3
Fig. 3
Extracted ion chromatograms from UHPLC–HRMS analysis of one of the urine samples showing the presence of several AC-metabolites
See this image and copyright information in PMC

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