An investigation into an outbreak of pancytopenia in cats in the United Kingdom

Abstract

Background In spring 2021 increasing numbers of cats presenting with severe pancytopenia were noted in United Kingdom (UK). Objective To describe process and outcome of the investigation performed into the outbreak of pancytopenia in cats. Animals Five hundred and eighty client owned cats that presented with severe bi‐ or pancytopenia of unknown cause. Methods Real‐time data collection was performed by an online registration forum available to all veterinary surgeons in UK. Data collected included demographics, clinicopathological findings, diagnostic testing, dietary and drug history, outcome and COVID household status. Mycotoxicological feed analysis was performed on feed samples of 3 diets frequently mentioned in the database and 3 control diets. Results Five hundred and eighty cats presented to 378 veterinary practices were included for analysis. Case fatality rate was 63.3%. Dietary history was available for 544 (93.8%) cats, of which 500 (86%) were fed 1 of 3 diets (which were recalled midinvestigation). 54 (9.3%) cats were not fed a recalled product, with diet information unknown in 26 (4.5%) cats. Analysis of feed samples revealed concentrations of hematotoxic trichothecene T‐2/HT‐2 mycotoxins greater than recommended by the European Commission in 5/7 recalled diet samples but in none of control diet samples. The trichothecene mycotoxin diacetoxyscirpenol (DAS) was detectable in all recalled diet samples but not in any of control samples. Conclusion and Clinical Importance Contaminated‐feed induced trichothecene mycotoxicosis should be considered as a differential diagnosis for pancytopenia in cats.

Clinical and clinicopathological features and outcomes of cats with suspected dietary induced pancytopenia

“…Case fatality rate in this study was higher compared to the case fatality rate reported for the overall affected cohort 1 . This is thought to be due to 2 main factors.…”

“…This is thought to be due to 2 main factors. One, the reported case fatality rate for the overall affected cohort is likely an underestimation due to the nature of reporting and capture of data (“1 moment only”) in that study and also due to the fact that it is very likely that not all affected cats were registered on our data base 1 . In contrast, the case fatality rate reported here is likely an overestimation, as availability of bone marrow examinations results was an inclusion criterion.…”

“…This study describes clinicopathological features, in particular bone marrow examination findings, of cats presenting with pancytopenia that were exposed to a diet containing the trichothecene mycotoxins T‐2, HT‐2, and diacetoxyscirpenol (DAS) in higher concentrations than advised 2 . Demographics, duration and type of clinical signs, results of hematological and biochemical analysis, as well as infectious disease testing results of presented cats in this study did not differ from the cohort involved in the epidemiological investigation of the outbreak of pancytopenia in cats in the United Kingdom, 1 and therefore this case series can be presumed to be a representative sample.…”

“…Of the cats from a multicat household, other cats in the household were diagnosed with bi‐ or pancytopenia in 19 (61%) cases. Thirteen cats (26%) were fed diet A, 23 (46%) cats diet B, and 14 cats (28%) diet C 1 . Twenty‐five cats (50%) were recorded as being fed solely on a dry diet, whereas 22 cats (44%) were fed a combination of wet and dry.…”

“…In spring 2021 an outbreak of pancytopenia in cats occurred in the United Kingdom and investigations into an underlying cause revealed a strong epidemiological link to diet leading to the recall of 3 commercial feline diets. 1 Analysis of representative feed samples from recalled diet brands revealed a concentration of the trichothecene mycotoxins T‐2 and HT‐2 up to 5 times higher than recommended by the European Commission. 2…”