Acute phase protein concentrations following serial procaine penicillin G injections in horses.

BACKGROUND: Acute phase protein (APP) measurement is used to detect inflammation. Intramuscular (IM) injections could cause tissue injury and induce an acute phase response (APR). OBJECTIVES: To evaluate the effects of IM procaine penicillin G (PPG) injections on APP concentrations in horses. STUDY DESIGN: Prospective longitudinal design. METHODS: PPG was administered intramuscularly to six horses, twice daily, for 5 days. Plasma fibrinogen (FIB), serum amyloid A (SAA), haptoglobin (HAP), creatine kinase (CK), and aspartate aminotransferase (AST) were quantified daily for 5 days before the first injection, during the course of administration, and for 4 days after the final dose. Analytes were quantified every other day for the remaining 16 days. Data were compared using a parametric or non-parametric repeated measures ANOVA and a Tukey's or Mann-Whitney rank sum test, respectively. Significance was set at p < 0.05. RESULTS: CK was increased over baseline (mean ± SD: 200 ± 74 IU/L) on Days 1-6 (p < 0.001 to p = 0.02, mean ± SD: 723-1177 ± 355-544 IU/L) and AST was increased above baseline (mean ± SD: 233 ± 58 IU/L) on Days 2-7 and 10 (p < 0.001 to p = 0.05, mean ± SD: 307-437 ± 79-146 IU/L). Increased FIB was noted over baseline (mean ± SD: 177 ± 30 mg/dl) on Days 6-8 and 10 (p = 0.02 to p = 0.03, mean ± SD: 234-252 ± 33-49 mg/dl). SAA was increased above baseline (mean ± SD: 4.7 ± 2.9) on Day 6 (p = 0.02, mean ± SD: 113 ± 186 µg/ml). There was no change in HAP. MAIN LIMITATIONS: Healthy horses were used, small sample size, and a lack of a negative control group. CONCLUSIONS: Serial intramuscular procaine penicillin G (IM PPG) injections may result in increased positive APP concentrations in horses and this must be considered when these test results are interpreted.

Evaluation of a point-of-care benchtop analyzer for quantitative measurement of C-reactive protein in canine serum and plasma.

BACKGROUND: Canine C-reactive protein (cCRP) is an acute-phase protein that increases dramatically with inflammation and has potential utility in monitoring disease progression and response to treatment. Rapid, automated point-of-care test (POCT) formats could enhance the clinical utility of cCRP measurement. OBJECTIVES: We aimed to evaluate the VetChroma canine-specific POCT assay for the quantitative measurement of cCRP in canine serum or plasma. METHODS: Serum and plasma from discarded canine diagnostic samples were used. Evaluation included intra- and inter-assay coefficients of variation and observed total error (TEobs ), linearity and spike recovery, the effect of interfering substances and sample matrices, and a method comparison study. RESULTS: Intra-assay variation ranged from 2.5%-6.1%, and inter-assay variation ranged from 2.1%-5.4%. The TEobs ranged from 15.1%-19.7%. The assay was linear over the manufacturer's analytical range with no evidence of constant or proportional bias. Recovery of purified cCRP from canine serum ranged from 116.2% to 138.4%. Hemolysis, icterus, and turbidity did not interfere with the assay. The comparison of paired plasma and serum samples revealed constant and proportional bias. Comparison of the VetChroma cCRP assay to a commercial cCRP ELISA revealed significantly different results. CONCLUSIONS: The VetChroma cCRP assay has acceptable test performance to measure serum cCRP concentration. The POCT protocol and test kit are valid for clinical use, although results obtained using other cCRP assays or plasma may not be directly compared.

Comparison of selected serum biochemistry measurements between the Nova Prime Plus VET, Nova pHOx Ultra, and Beckman Coulter AU680 analyzers in dogs.

BACKGROUND: Blood gas chemistry analyzers typically produce results faster and use smaller sample volumes than reference chemistry analyzers. However, results may not be comparable between blood gas chemistry analyzers and reference chemistry analyzers or between different models of blood gas chemistry analyzers. This could suggest the use of separate reference intervals and, thus, has implications when making clinical decisions. OBJECTIVE: We aimed to perform method comparison studies to evaluate selected canine serum biochemical values obtained using the Nova Stat Profile Prime Plus VET (Prime Plus VET), Stat Profile Nova pHOx Ultra (Ultra), and Beckman Coulter AU680 (Beckman) analyzers. We hypothesized that the three analyzers would be identical within inherent imprecision. METHODS: Jugular venous blood samples were collected from 103 endurance-trained sled dogs, and serum was harvested and stored for analysis. Results for serum chloride, potassium, sodium, creatinine, and urea nitrogen concentrations obtained from the Prime Plus VET and Ultra analyzers were compared with results from the Beckman analyzer, which was considered to be a reference method. Results for serum chloride, potassium, sodium, creatinine, urea nitrogen, and L-lactate concentrations obtained from the Prime Plus VET and Ultra analyzers were compared. Passing-Bablok regression and Bland-Altman plots were used for method comparison. RESULTS: Significant (P < 0.05) constant or proportional bias was found for many analytes for all three method comparison studies. CONCLUSIONS: Due to the presence of statistically significant differences between all three analyzers that may be clinically relevant, it is recommended that reference intervals be created for new blood gas analyzers, even when similar methodologies are used.

The effect of age and sex on selected hematologic and serum biochemical analytes in 4,804 elite endurance-trained sled dogs participating in the Iditarod Trail Sled Dog Race pre-race examination program.

Endurance-trained sled dogs provide a unique translational model to characterize changes in hematologic and serum biochemical analytes due to the aging process. The primary objective of this study was to determine the effect of age and sex on specific hematologic and serum biochemical parameters in the endurance trained sled dog. Longitudinal and cross-sectional data were analyzed from 9,746 blood and serum samples from 4,804 dogs collected over 7 years as part of the Iditarod Trail Sled Dog Race pre-race examination program. Mixed models analysis was used for statistical analysis and P < 0.01 was considered significant. Dogs ranged from 1-12 years of age and 39% were female. Serum total calcium and phosphorus concentrations and white blood cell count decreased nonlinearly to asymptotic values by 6.6, 3.1, and 6.9 years of age, respectively, equivalent to estimated physiologic ages in human years of 44, 27, and 46 years. Serum glucose concentrations reached their lowest value at 7.8 years of age, equivalent to an estimated human physiologic age of 50 years, after which time the concentration increased. Serum globulin concentrations increased with age, but nonlinearly for females and linearly for males. Most sex-related differences were <5%; however, females had lower serum urea nitrogen (14.7%) and creatinine (7.3%) concentrations, lower serum alanine aminotransferase activity (16.6%), and higher serum total bilirubin concentration (12.8%) and platelet count (6.0%). The endurance-trained sled dog provides an excellent model to separate the physiologic effects of age from those of a sedentary lifestyle on hematologic and serum biochemical analytes.

The utility of intraoperative impression smear cytology of intracranial granular cell tumors: Three cases.

Two adult male dogs (a 7-year-old shorthaired Chihuahua and 14-year-old Shih Tzu) and one adult female dog (a 9-year-old Maltese) presented for evaluation of new-onset seizure activity. Magnetic resonance imaging of the brain demonstrated a large, poorly marginated T2-weighted hyperintense, and strong contrast enhancing extra-axial mass in each case. A surgical biopsy for histopathologic evaluation was elected in all cases, and intraoperative impression smears were successfully obtained. Intraoperative cytology identified a homogenous population of round to polygonal cells with central to eccentric nuclei, coarse chromatin, and variably amphophilic to eosinophilic granular cytoplasm. Cytologic findings led to a suspected diagnosis of granular cell tumor (GCT) in all cases. Histopathologic review identified a densely cellular, unencapsulated neoplastic mass comprised of sheets of large round to polygonal cells with abundant eosinophilic cytoplasm containing numerous eosinophilic intracytoplasmic granules, confirming the diagnosis of GCT in all cases. The cases reported here are unique in that they reveal an accurate intraoperative cytologic diagnosis of a rare canine central nervous system neoplasm. Intraoperative cytology of the intracranial masses could provide clinicians with important and quick diagnostic and prognostic information; therefore, expediting decisions made intraoperatively. Further research is warranted to determine the diagnostic accuracy of intraoperative cytology for neoplasia in veterinary patients.

Basal cell enumeration does not predict malignancy in canine perianal gland tumor cytology.

BACKGROUND: Perianal (hepatoid) gland tumors are common in dogs, and the distinction between the benign and malignant forms is clinically important. Cytology of these tumors typically contains many large hepatoid cells and fewer small basal cells. OBJECTIVES: The objective of this study was to determine whether the proportion of the smaller basaloid reserve cells in cytologic samples from perianal tumors correlates with malignancy. METHODS: Eighty-three cases of cytologically diagnosed perianal gland tumors with corresponding histopathologic sections were identified from two separate institutions and included six (7.2%) malignant tumors and 77 (92.8%) benign tumors. The proportion of basal cells from each sample was evaluated. RESULTS: No difference between these groups was found, although the study was sufficiently powered to detect an approximately 1.5-fold change in basal cell proportion. CONCLUSIONS: This report found no evidence that the proportion of basal cells in canine perianal tumor cytology is an indication of the potential for malignancy. We, therefore, do not recommend citing this feature in cytologic reports or when communicating with clinicians.

Biochemical survey of free-roaming cats (Felis catus) in New York City presented to a trap-neuter-return program.

Free-roaming cats in New York, NY, USA, that presented to a trap-neuter-return program were surveyed for biochemical data. One hundred and one cats had blood collected for a plasma biochemistry panel after the induction of surgical anesthesia. Reference intervals for 18 analytes were generated for the sample population, along with age-specific reference intervals when statistically appropriate. Age groups (juveniles and adults) differed in 10 of the 18 analytes measured, including protein levels and albumin/globulin ratio, aspartate aminotransferase, alkaline phosphatase, creatine kinase, creatinine, phosphorus, calcium and potassium. No differences were found between males and females. This is the first report of biochemical reference intervals for a group of free-roaming cats within the USA.

Dual infection with Pythium insidiosum and Blastomyces dermatitidis in a dog.

A 4-year-old male neutered Labrador Retriever with severe gastrointestinal signs, but no respiratory signs, was diagnosed with multifocal pyogranulomatous gastritis, enteritis, and lymphadenitis with intralesional hyphae and multifocal pyogranulomatous pneumonia with intralesional yeast. Based on cytologic evaluation, histologic examination with special stains, and immunohistochemical analysis of tissues collected antemortem or at necropsy, dual infections with Pythium insidiosum and Blastomyces dermatitidis were detected and are reported for the first time.