Diagnosis of feline chronic inflammatory enteropathies (CIE) and the differentiation from small cell intestinal lymphoma (SCL) can be challenging. Intestinally expressed calprotectin (S100A8/A9 protein complex) appears to be part of the complex pathogenesis of feline chronic enteropathies (FCE). Fecal calprotectin is a non-invasive biomarker for intestinal inflammation in humans and dogs but has not yet been evaluated in cats. We hypothesized that fecal calprotectin (fCal) concentrations are increased in FCE, correlate with clinical and/or histologic disease severity, and distinguish cases of CIE from SCL. This case–control study included fecal samples and patient data from cats with CIE (n = 34), SCL (n = 17), other gastrointestinal (GI) diseases (n = 16), and cats with no clinical signs of GI disease (n = 32). fCal concentrations were measured using the immunoturbidimetric fCal turbo assay (Bühlmann Laboratories). Compared to healthy cats, fCal concentrations were significantly increased in CIE, SCL, and other diseases (all p < 0.0001), but were not different between these three groups (all p > 0.05), or between cats with extra-GI diseases and healthy controls. These findings suggest that fCal may have utility as a clinical biomarker for FCE but not for intestinal disease differentiation. It further supports the role of calprotectin in the pathogenesis of the spectrum of FCE, which includes CIE and SCL.

Background: Chronic enteropathies (CE) are common in cats and reliable biomarkers that can distinguish different causes and predict or monitor response to treatment are currently lacking. Hypothesis: To evaluate certain acute phase proteins in feces that could potentially be used as biomarkers in cats with CE. Animals: Twenty-eight cats with either inflammatory bowel disease (IBD; n = 13), food-responsive enteropathy (FRE; n = 3) or small cell gastrointestinal lymphoma (SCGL; n = 12) and 29 healthy control cats were prospectively enrolled. Methods: Fecal concentrations of haptoglobin, alpha-1-acid-glycoprotein (AGP), pancreatitis-associated protein-1 (PAP-1), ceruloplasmin, and C-reactive protein (CRP) were measured using Spatial Proximity Analyte Reagent Capture Luminescence (SPARCL) immunoassays before and after initiation of treatment. Cats were treated with diet and/or prednisolone (IBD cats), plus chlorambucil (SCGL cats). Results: Compared with controls, median fecal AGP concentrations were significantly lower (25.1 vs 1.8 μg/g; P = .003) and median fecal haptoglobin (0.17 vs 0.5 μg/g), PAP-1 (0.04 vs 0.4 μg/g) and ceruloplasmin (0.15 vs 4.2 μg/g) concentrations were significantly higher (P < .001) in cats with CE. Median fecal AGP concentrations were significantly lower (P = .01) in cats with IBD and FRE (0.6 μg/g) compared with cats with SCGL (10.75 μg/g). A significant reduction was found in CE cats after treatment for median fecal ceruloplasmin concentrations (6.36 vs 1.16 μg/g; P = .04). Conclusions: Fecal AGP concentration shows promise to differentiate cats with SCGL from cats with IBD and FRE. Fecal ceruloplasmin concentrations may be useful to objectively monitor response to treatment in cats with CE.

Background: Chronic enteropathies (CE) are common in cats, and alterations of the intestinal microbiota might be involved in the pathogenesis. Hypothesis/Objectives: To evaluate the efficacy of a single enema fecal microbiota transplantation (FMT) in improving intestinal dysbiosis and clinical scores in cats with CE. Animals: Twenty-eight cats with either chronic inflammatory enteropathy (CIE; n = 19) or small cell gastrointestinal lymphoma (SCGL; n = 9) were prospectively enrolled. Methods: Eleven cats were randomly selected to receive a single enema FMT (FMT-group), and 17 cats were used as controls. Clinical activity was determined using the Feline Chronic Enteropathy Activity Index (FCEAI), and intestinal dysbiosis was determined using the feline dysbiosis index (DI) on the day of FMT (T0) and 30 days after FMT (T1). Results: At T0, 14/28 cats had an abnormal DI > 0. No significant difference was found in the DI from T0 to T1 in the FMT group (mean[SD]: 0.01[2.5] vs. 0.7[2.1]; p = 0.47). No significant difference was found in the DI between the FMT group and the control group at T1 (mean[SD]: −0.7[2.1] vs. 0.8[1.8]; p = 0.92). FCEAI significantly decreased at T1 compared to T0 in the FMT group (median[IQR] 10.0[7.7–11.3] vs. 4.5[4–5]; p = 0.002). No significant difference was found in the FCEAI between the FMT group and the control group at T1 (median[IQR] 4.5[4–5] vs. 4[3–5.75]; p = 0.64). Conclusions: In this study, single enema FMT did not lead to a significant improvement in DI or FCEAI in cats with CE compared to controls.

Background: Chronic enteropathies (CE) are common in cats. Reliable biomarkers that can distinguish different causes and predict or monitor responses to treatment are currently lacking. Hypothesis/Objectives: Evaluate calprotectin concentrations in serum and feces as potential biomarkers in cats with CE. Animals: Forty-three cats with either chronic inflammatory enteropathy (CIE; n = 25) or small cell gastrointestinal lymphoma (SCGL; n = 18) and 36 healthy cats were prospectively enrolled. Methods: Fecal and serum calprotectin concentrations were determined before and during treatment. Cats with CIE were treated with diet, prednisolone, or diet and prednisolone, and cats with SCGL were treated with prednisolone plus chlorambucil with or without diet. Results: Compared to controls, fecal calprotectin concentration was significantly higher in cats with CE (median, ≤ 161 ng/g; range, ≤ 161–2827 vs. median, ≤ 161 ng/g; range, ≤ 161–790; p = 0.01). No significant differences were found in fecal (median ≤ 161 ng/g; range, ≤ 161–1920 vs. median, 189 ng/g; range, ≤ 161–2827; p = 0.3) or serum calprotectin (median, ≤ 1291 mg/L; range, ≤ 1291–15 358 vs. median, ≤ 1291 mg/L; range, ≤ 1291–6422; p = 0.99) between cats with CIE and cats with SCGL. Fecal calprotectin was significantly decreased after treatment in cats with CE (median, ≤ 161 ng/g; range, ≤ 161–1897 vs. median, ≤ 161 ng/g; range, ≤ 161–656; p = 0.02). Conclusions: Fecal calprotectin concentration might be a good biomarker for diagnosis and treatment monitoring for a subset of cats with CE. Serum calprotectin concentrations do not seem to be useful for diagnosis or treatment monitoring in cats with CE. Neither fecal nor serum calprotectin concentrations could differentiate cats with CIE from cats with SCGL.

Objectives: Serial measurement of serum feline pancreatic lipase immunoreactivity (fPLI) and trypsin-like immunoreactivity (fTLI) concentrations in cats with chronic enteropathy (CE) has not been previously reported. The aim of the current observational study was to serially evaluate serum fPLI and fTLI concentrations in cats with different forms of CE. Methods: A total of 60 cats with CE were included, diagnosed either with immunosuppressive-responsive enteropathy (IRE; n = 22), food-responsive enteropathy (FRE; n = 7) or low-grade intestinal T-cell lymphoma (LGITL; n = 32, one diagnosed previously as FRE progressed to lymphoma). Serum fPLI and fTLI concentrations were measured in 252 and 245 serum samples, respectively, from 60 cats with CE at initial presentation and during re-examination. Results: Serum fPLI concentrations indicative of pancreatitis were found in 3/60 cats (one with IRE and two with LGITL) at initial presentation and in an additional 8/60 cats (four with IRE and four with LGITL) during treatment (24/252 serum samples). Serum fTLI concentrations indicative of exocrine pancreatic insufficiency were found in 2/60 cats (both with IRE) at initial presentation and during re-examination (n = 3/245). None of the cats with FRE had fPLI concentrations above or fTLI concentrations below the respective reference intervals (RIs). Conclusions and relevance: Serum fPLI concentrations may fluctuate during treatment in a subset of cats with IRE or LGITL and, in some cats, are indicative of pancreatitis. Serum fTLI concentrations may vary within and outside the RI in a relatively small proportion of cats with IRE. The long-term clinical importance of these findings requires further study.