Hair nicotine concentration of cats with gastrointestinal lymphoma and unaffected control cases.

BACKGROUND: A previous study showed an association between owner-reported exposure to environmental tobacco smoke (ETS) and lymphoma in cats. This study aimed to investigate the association between ETS exposure and gastrointestinal lymphoma in cats, using hair nicotine concentration (HNC) as a biomarker. METHODS: This was a prospective, multi-centre, case-control study. Gastrointestinal lymphoma was diagnosed on cytology or histopathology. Hair samples were obtained from 35 cats with gastrointestinal lymphoma and 32 controls. Nicotine was extracted from hair by sonification in methanol followed by hydrophilic interaction chromatography with mass spectrometry. Non-parametric tests were used. RESULTS: The median HNC of the gastrointestinal lymphoma and control groups was not significantly different (0.030 ng/mg and 0.029 ng/mg, respectively, p=0.46). When the HNC of all 67 cats was rank ordered and divided into quartiles, there was no significant difference in the proportion of lymphoma cases or controls within these groups (p=0.63). The percentage of cats with an HNC≥0.1 ng/mg was higher for the lymphoma group (22.9%) than the control group (15.6%) but failed to reach significance (p=0.45). CONCLUSION: A significant association was not identified between HNC (a biomarker for ETS) and gastrointestinal lymphoma in cats; however, an association may exist and further studies are therefore required.

Alterations in amino acid status in cats with feline dysautonomia.

Feline dysautonomia (FD) is a multiple system neuropathy of unknown aetiology. An apparently identical disease occurs in horses (equine grass sickness, EGS), dogs, rabbits, hares, sheep, alpacas and llamas. Horses with acute EGS have a marked reduction in plasma concentrations of the sulphur amino acids (SAA) cyst(e)ine and methionine, which may reflect exposure to a neurotoxic xenobiotic. The aim of this study was to determine whether FD cats have alterations in amino acid profiles similar to those of EGS horses. Amino acids were quantified in plasma/serum from 14 FD cats, 5 healthy in-contact cats which shared housing and diet with the FD cats, and 6 healthy control cats which were housed separately from FD cats and which received a different diet. The adequacy of amino acids in the cats' diet was assessed by determining the amino acid content of tinned and dry pelleted foods collected immediately after occurrences of FD. Compared with controls, FD cats had increased concentrations of many essential amino acids, with the exception of methionine which was significantly reduced, and reductions in most non-essential amino acids. In-contact cats also had inadequate methionine status. Artefactual loss of cysteine during analysis precluded assessment of the cyst(e)ine status. Food analysis indicated that the low methionine status was unlikely to be attributable to dietary inadequacy of methionine or cystine. Multi-mycotoxin screening identified low concentrations of several mycotoxins in dry food from all 3 premises. While this indicates fungal contamination of the food, none of these mycotoxins appears to induce the specific clinico-pathologic features which characterise FD and equivalent multiple system neuropathies in other species. Instead, we hypothesise that ingestion of another, as yet unidentified, dietary neurotoxic mycotoxin or xenobiotic, may cause both the characteristic disease pathology and the plasma SAA depletion.