A case of T-cell chronic lymphocytic leukemia progressing to Richter syndrome with central nervous system involvement in a dog.

An 8-year-old neutered Beagle dog was presented with polyuria and polydipsia. Routine clinicopathologic testing showed a significant lymphocytosis and proteinuria. Lymphocytes were of small to intermediate in size with a mature morphology. Infectious disease screening was negative. PCR for antigen receptor gene rearrangements showed a clonal T-cell receptor (TCR) rearrangement consistent with T-cell chronic lymphocytic leukemia (CLL). Bone marrow cytology showed <30% lymphocytes, while the proportion in splenic fine-needle aspirate cytology was considered increased. The dog was initially monitored but started on prednisolone and chlorambucil therapy 2 months later due to worsening clinical signs and progressive lymphocytosis. After an additional 2 weeks, the dog developed multifocal spinal pain and single-node lymphadenomegaly. Cytology of the lymph node showed a monomorphic population of large lymphoblasts consistent with lymphoma. Cytology of a cerebrospinal fluid sample also showed large lymphoblasts. PCR for antigen receptor gene rearrangement at both sites showed a clonal TCR rearrangement of the same molecular size as in the initial leukemic cells. The dog was diagnosed with a transformation of the CLL to Richter syndrome (RS) with involvement of the central nervous system (CNS). Therapy was started with L-asparaginase and an increased dose of prednisolone; however, the dog was euthanized due to progressive clinical signs. To our knowledge, this is the first report of canine RS with direct involvement of the CNS.

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.

Determination of nicotine exposure in dogs subjected to passive smoking using methanol extraction of hair followed by hydrophilic interaction chromatography in combination with Fourier transform mass spectrometry.

There has been no previous assessment of the level of nicotine exposure in companion animals as a result of passive smoking. A method was developed for the determination of nicotine in dog hair where extraction was carried out by sonication in methanol. The levels of nicotine obtained by extraction with methanol were found to be comparable to the lengthier method involving digestion of the hair in 1M NaOH. The methanol extracts were injected directly onto a ZICHILIC column coupled to an Exactive high resolution Fourier Transform mass spectrometer. Endogenous nicotine was quantified against (2)H(4)-nicotine spiked into the extraction medium, linearity was found over a wide range with the calibration curve having a slope close to 1 indicating an equal response for nicotine and the deuterated internal standard, precision was determined to be ±1.9%. Nicotine was present in widely varying amounts in the hair of dogs belonging to smokers and was found to be absent from the hair of dogs belonging to non-smokers. In addition to nicotine, nicotine N-oxides, cotinine, nornicotine and nornicotine N-oxide could be detected in the hair of dogs belonging to smokers. The nicotine N-oxides were only observed in methanol extracts suggesting these compounds are not stable to the NaOH digestion process.