Calprotectin, also referred to as the S100A8/A9 protein complex, is involved in acute and chronic inflammatory responses. Fecal calprotectin concentrations have been demonstrated to be increased in dogs diagnosed with inflammatory bowel disease (IBD) and to decrease with successful treatment. Fecal calprotectin concentrations in dogs with IBD were also correlated with the severity of clinical signs, microscopic inflammatory lesions in the small intestine, and the need for more aggressive (i.e., anti-inflammatory/immunosuppressive) treatment (cut-off concentration: 15 μg/g). In-house canine calprotectin assays were found to also reliably measure calprotectin in feline samples. Given the lack of wide availability of the in-house canine calprotectin assay, the aim of the study was to assess the feasibility of measuring fecal calprotectin concentrations in dogs and cats by the commercial fCAL® turbo immunoassay used routinely for the diagnosis and monitoring of IBD in human medicine.

Fecal samples were obtained from 58 animals (45 dogs and 13 cats) with acute or chronic gastrointestinal disease (n=29), other diseases (n=11), and clinically healthy individuals (n=18). Fecal samples were collected into the CALEX® Cap stool extraction device, extracted at a 1:500 dilution, and stored frozen until analysis using the commercial fCAL® turbo particle-enhanced turbidimetric immunoassay. Statistical analysis was performed by a non-parametric (unpaired) group comparison, with statistical significance set at p<0.05.

Fecal calprotectin concentrations ranged from 0–3,468.5 μg/g (median: 18.9 μg/g) in this study, with a fecal calprotectin concentration of <10 μg/g in 28 (48.3%) animals, 10–50 μg/g in 8 (13.8%), 50–200 μg/g in 13 (22.4%), and >200 μg/g in 9 (15.5%). Significantly higher concentrations of fecal calprotectin were detected in dogs with acute or chronic gastrointestinal diseases (median: 89.7 μg/g; n=21) compared to healthy controls and patients with diseases not localized to the gastrointestinal tract (median: 0 μg/g; n=24; p=0.0017). Fecal calprotectin levels were also higher in cats with acute or chronic gastrointestinal diseases (median: 49.7 μg/g; n=8) compared to healthy controls and cats with conditions not localized to the gastrointestinal tract (median: 2.9 μg/g; n=5), but the difference did not reach significance (p>0.05).

These results suggest that the fCAL® turbo immunoassay can detect fecal calprotectin in dogs and cats and can separate those animals with gastrointestinal diseases from healthy controls. An assay validation is currently underway and will allow further studies on the clinical utility of the assay for fecal calprotectin in dogs and cats with gastrointestinal diseases.

Disclosures

Disclosures to report.
Dres. Gabris, Kock, and Niederberger are employed by Bühlmann Laboratories AG where the fCAL® turbo immunoassay is offered on a fee-for-service basis.