BackgroundThe measurement of pancreatic lipase is important for the diagnosis of feline and canine pancreatitis. Recent studies have claimed that lipase assays using the 1,2‐o‐dilauryl‐rac‐glycero‐3‐glutaric acid‐(6’‐methylresorufin) ester (DGGR) as a substrate are more specific for measuring pancreatic lipase than traditional lipase assays. However, the analytical specificity of this assay for pancreatic lipase has not been demonstrated.ObjectivesWe aimed to determine whether hepatic and/or lipoprotein lipases can interfere with the DGGR‐based assay results in cats and dogs. We, therefore, compared plasma lipase activities measured using DGGR‐based and pancreatic lipase immunoreactivity (PLI) assays before and after administering heparin, known to cause the release of hepatic and lipoprotein lipases, in cats and dogs.MethodsHeparin was administered in six cats and six dogs. Blood was collected at baseline and 10, 20, 30, 60, and 120 minutes after heparin administration. Lipase activity was measured using a DGGR‐based assay, and PLI concentrations were measured using the Spec fPL and cPL assays for cats and dogs, respectively.ResultsPlasma lipase activities, as measured using the DGGR‐based assay, increased significantly 10 minutes after heparin administration in both cats (P = .003) and dogs (P = .006) and returned to baseline by 120 minutes. In contrast, PLI concentrations showed no significant changes after heparin administration.ConclusionsDGGR is not only hydrolyzed by pancreatic lipase but also by hepatic lipase, lipoprotein lipase, or both, in cats and dogs. Since these extrapancreatic lipases are also naturally present in cats and dogs, they could contribute to the lack of analytical specificity for the DGGR‐based assays.

An 8-month-old female spayed domestic shorthair cat, weighing 3 kg, was presented for anorexia, lethargy, and occasional episodes of vomiting and soft stools during the previous 2 days. There was no historical evidence of toxin or drug exposure. The cat was completely vaccinated with PureVax Feline RCPCh, and PureVax Rabies, (Boehringer Ingelheim) and was currently receiving antiparasitic treatments (Broadline; Boehringer Ingelheim). The last vaccination and last antiparasitic treatment had been administered 4 and 1 month prior to presentation, respectively. The physical examination revealed lethargy, fever (39.8°C; RI 38.0-39.2°C), and moderate dehydration (7%). The CBC (ADVIA 2120i; Siemens) indicated mild anemia (25.4%; RI 28%-47%), with a MCV of 42.3 fL, RI 41.3-52.6 fL, MCHC of 31.9 g/dL, RI 27.0-32.8 g/ dL, and reticulocyte count of 0.13 × 10 9 /L, RI 0.0-1.3 × 10 9 /L. There was also a moderate to severe leukopenia (2.12 × 10 9 /L; RI 6.3-19.6 × 10 9 /L) with severe neutropenia (0.54 × 10 9 /L; RI 3.0-13.4 × 10 9 /L) (Table 1). The review of a blood smear stained with New Methylene Blue and Giemsa indicated the lack of an appreciable reticulocytosis and the presence of severe neutropenia. A comprehensive serum biochemistry profile, fecal examination, urinalysis, and thoracic and abdominal radiographs were unremarkable. The cat

Reticulocyte indices are used to characterize anemia, including the identification of regeneration. In people, the immature reticulocyte fraction (IRF), percentage of hypochromic red blood cells (%HYPO‐RBC), and other reticulocyte indices have been used as earlier indicators of erythropoiesis and as valuable monitoring tools in the assessment of various therapies. The reference intervals (RI) of the IRF and %HYPO‐RBC have not been reported in dogs. The objective of this study was to establish RIs for novel variables (IRF, %HYPO‐RBC, and CH‐delta) and assess RIs for more commonly reported reticulocyte indices in healthy dogs. RIs were calculated from blood results retrospectively collected from 106 client‐owned healthy dogs at the time of induction into a blood donor program using the ADVIA 2120 hematology analyzer (Siemens Healthcare Diagnostics). For the calculation of RIs, appropriate tests were applied for outlier detection and normality assessment. For variables normally distributed, RIs and their respective 90% confidence intervals (CIs) were calculated using parametric methods, while for variables not normally distributed, robust methods were used and bootstrapping for calculating the 90% CIs. The following RIs were established: reticulocyte hemoglobin content (CHr) 24.5‐28 pg, mean reticulocyte volume (MCVr) 85.9‐99.3 fL, mean corpuscular hemoglobin concentration of reticulocytes (CHCMr) 271.0‐306.3 g/L, IRF 10.4%‐43.5%, CH‐delta 0.5‐4.3 pg, and percentage of hypochromic red blood cells (%HYPO‐RBC) 0.10%‐0.80%. The results of this study provide RIs for novel reticulocyte variables. Further studies are required to determine the clinical utility of IRF, %HYPO‐RBC, and CH delta as early indicators of erythropoietic activity in canine patients.