Hyperlipasemia in 6 dogs with pancreatic or hepatic neoplasia: evidence for tumor lipase production

Abstract: A marked increase in serum pancreatic lipase (PL) activity with minimal concurrent increase in serum α-amylase activity was observed in 6 dogs with pancreatic or hepatic neoplasia. Serum PL activity ranged from 5410 U/L to 42,900 U/L, 11 to 93 times the upper reference limit for our laboratory. Neoplasms included pancreatic adenocarcinoma (n=3), endocrine carcinoma (n=2), and hepatic carcinoma of unknown origin (n=1). Tumor tissue and normal canine pancreatic tissue were stained histochemically with diastase periodic acid-Schiff to demonstrate zymogen granule content, and immunohistochemically with human monoclonal antibody for PL. Normal canine pancreatic tissue stained positive for both zymogen granule content and PL. Five of the 6 tumors stained positive for zymogen granule content, and 2 of the 6 tumors stained positive for PL. Together, the his-tochemical and immunohistochemical staining patterns suggested tumor PL production in 5 of the 6 dogs. Marked, unexplained hyperlipasemia may be a noninvasive indicator and biochemical marker for neoplasia of the pancreas and liver in dogs.     

Detection of serum alpha-fetoprotein in dogs with hepatic tumors.

Serum alpha-fetoprotein (AFP) concentration was detected by use of 2 commercially available kits containing antibodies to human AFP--a radioimmunoassay and an enzymetric test. Using neonatal canine serum (a source high in AFP), it was determined that reagents from both kits were able to bind to canine AFP, but a significant difference was detected in AFP concentration. The enzymetric test was superior in detecting canine AFP. Sera from dogs were classified into 6 groups: from dogs with primary hepatic tumors only (group 1); from dogs with primary hepatic tumors and other tumors (group 2); from dogs with normal liver but with other types of neoplasia (group 3); from dogs with nonneoplastic hepatic disease and tumors originating in other organs (group 4); from dogs with nonneoplastic hepatic disease only (group 5); and from clinically normal dogs (group 6). Serum biochemical determinations (alkaline phosphatase, alanine transaminase, albumin, total protein, total bilirubin, and serum bile acids) and values from the 2 AFP assays were obtained for all dogs. Serum AFP concentration detected by the enzymetric test was significantly higher in dogs with hepatocellular carcinoma and cholangiocarcinoma. Values greater than 250 ng/ml were detected in 5 of 9 dogs with cholangiocarcinoma and in 3 of 4 dogs with hepatocellular carcinoma. High serum AFP concentration also was indicative of liver involvement in 2 of 3 dogs with primary hepatic lymphosarcoma; 2 dogs had values greater than 225 ng/ml. Serum AFP concentration in dogs with other types of hepatic tumors was less than 250 ng/ml, and serum AFP concentration could not be correlated with such tumors.(ABSTRACT TRUNCATED AT 250 WORDS)     

A non-radiometric method for measuring serum thymidine kinase activity in malignant lymphoma in dogs

The aim of this study was to evaluate an enzyme-linked immunosorbent assay (ELISA), for determination of serum thymidine kinase 1 (sTK1) activity in dogs with malignant lymphoma (ML) and compare it with a thymidine kinase (TK) radioenzymatic assay (TK-REA). The TK-REA has recently been shown to be useful in determining the clinical stage and prognosis in canine ML. In addition, serum lactate dehydrogenase (LDH) was measured. Forty-five dogs were included in the study. Sixty serum samples from these dogs, stored in a tumour serum sample bank (stored at -20 degrees C), were analysed. Apart from 37 dogs with ML, four normal dogs as well as two dogs with mammary carcinomas, one dog with bladder carcinoma, and one dog with malignant fibrous histiocytoma were included. Staging of ML was based on the modified World Health Organization (WHO) staging system for canine ML. The diagnosis of all tumours was verified by histopathology. The TK activity (units per litre [U/L]) ranged from 1.0 to 607.9 in the TK-REA analysis and from 1.1 to 510 in the TK-ELISA (normal reference value <7U/L). The range for LDH was between 12 and 1194 U/L (normal reference value <228 U/L). There was a significant correlation between the TK-REA and the TK-ELISA. The correlation coefficient (CC) was 0.97 and the standard error of the estimate (SEE) was 3.7 U/L. There was no correlation between LDH and either the TK-REA or the TK-ELISA (CC=0.53 for both assays; SEE=26.7 and 12.7 U/L, respectively). Most of the variation in LDH was still within the normal reference range. The mean LDH in dogs with high-stage (stage IV+V) disease was 201.9 U/L. The corresponding values for the TK-REA and TK-ELISA were 109 and 109.9 U/L, respectively. The significant relation between the TK-REA and the TK-ELISA was confirmed by Bland-Altman analysis. The TK-ELISA assay, because of its relative simplicity, will permit measurement of TK in cases of ML in dogs to become a routine procedure.     

Hematologic abnormalities and flow cytometric immunophenotyping results in dogs with hematopoietic neoplasia: 210 cases (2002–2006)

Background: Growing interest in veterinary oncohematology has facilitated the recent development and advancement of new techniques, such as flow cytometry, for immunophenotyping hematopoietic neoplasia in animals. Objective: The aim of this retrospective study was to characterize hematologic abnormalities and flow cytometric immunophenotyping (FCI) results in cases of hematopoietic neoplasia in dogs. Methods: Signalment, CBC data, and FCI results were obtained for 210 dogs with blood samples submitted to our laboratory. Immunophenotyping was carried out using an Epics XL‐MCL flow cytometer and a panel of 10 antibodies (CD45, CD3, CD4, CD8, CD79, CD21, CD14, CD34, CD41/61, CD61). The prevalence and severity of hematologic abnormalities was determined for the different types of hematopoietic neoplasms. Results: Based on cell morphology and phenotype, cases were classified as: acute lymphoblastic leukemia (ALL, n=51), acute myeloid leukemia (AML, n=33), chronic lymphocytic leukemia (CLL, n=61), and leukemic high‐grade lymphoma (L‐HGL, n=65). Most cases of ALL (47/51) and L‐HGL (41/65) had a B‐cell phenotype, while most cases of CLL (54/61) had a T‐cell phenotype, with a high prevalence of the large granular lymphocyte subtype (49/61). Anemia was found in 85% of all cases and was significantly more severe in ALL and AML compared with CLL and L‐HGL. Neutropenia was seen in 64–78% of acute leukemias (AML and ALL) in contrast to no cases of CLL and 11% of L‐HGL. Thrombocytopenia was seen in 88–90% of acute leukemias in contrast to 15% of CLL and 40% of L‐HGL. Thrombocytopenia was more prevalent (71% vs 22%) and significantly more severe in T‐cell vs B‐cell L‐HGL. Conclusion: A standard CBC is useful in suggesting the type of hemoproliferative disorder and may also help to predict the phenotype, especially in cases of L‐HGL.     

Phase I evaluation of low-dose suramin as chemosensitizer of doxorubicin in dogs with naturally occurring cancers

BACKGROUND: Low and nontoxic concentrations (10-50 microM) of suramin, which is a nonspecific inhibitor of multiple growth factors, including fibroblast growth factors, enhances the activities of cytotoxic chemotherapeutic agents, such as doxorubicin and paclitaxel, both in vitro and in vivo. Suramin has not been evaluated as a chemosensitizing agent in dogs with cancer. HYPOTHESIS: Nontoxic suramin can be used safely as a chemosensitizer in dogs. ANIMALS: Sixteen dogs of various breeds with measurable tumors were treated; 1 dog that had undergone amputation for osteosarcoma received adjuvant therapy. METHODS: The dogs received 53 courses of treatment with suramin in combination with doxorubicin. The suramin dosage was 6.75 mg/kg IV 3 h before standard doxorubicin administration every 2 weeks. The pharmacokinetics and clinical efficacy were determined. RESULTS: The pharmacokinetics of low-dose suramin followed a 2-compartment model with half-lives of 2 h and 6 days. The distribution volume was a 0.34 +/- 0.12 L/kg, and clearance was 1.86 +/- 0.76 mL/kg/h. During the time interval that doxorubicin was present at therapeutically active concentrations (ie, from the start of infusion to 24 hours), the plasma concentrations were maintained within 20% of the target range (8-60 microM) in 72% of the treatments. The toxicity of the suramin/doxorubicin combination was mild and comparable to the toxicity expected for doxorubicin monotherapy. Objective partial responses were observed in 2 out of 16 evaluable dogs (13%). All 5 dogs that previously received doxorubicin showed improved responses to the suramin/doxorubicin combination. CONCLUSIONS AND CLINICAL IMPORTANCE: A fixed, low-dose suramin regimen yields the desired target plasma concentrations in most dogs, and appears to enhance the activity of doxorubicin without enhancing toxicity.     

Evaluation of an insulin zinc suspension for control of naturally occurring diabetes mellitus in dogs

OBJECTIVE: To evaluate duration of action of an insulin zinc suspension (Caninsulin, Intervet) in spontaneously occurring cases of canine diabetes mellitus and suitability of its use as a once daily administered insulin for treatment of this disease. DESIGN: Eight client-owned canine diabetics were included in a prospective pilot study. All dogs had been treated with Caninsulin for a minimum of 2 months and were considered on clinical grounds to be adequately stabilised. PROCEDURE: Dogs were hospitalised for 24 h and blood collected every 2 h via indwelling venous catheters for blood glucose determination. RESULTS: Once daily Caninsulin administration failed to maintain glycaemic control for greater than 13 h in five of eight dogs, but acceptable blood glucose concentrations were maintained for 22 h and greater than 24 h in two others. One dog became distressed during hospitalisation and the blood glucose curve did not show an identifiable response to the insulin. CONCLUSION: Most diabetic dogs may require twice daily administration of Caninsulin for satisfactory glycaemic control, but once daily administration may be adequate in some animals. More comprehensive investigation into duration of activity of Caninsulin is warranted.     

Plasma L-carnitine concentration in healthy dogs and dogs with hepatopathy

BACKGROUND: L-Carnitine has an essential role in lipid metabolism. Disturbances of L-carnitine metabolism can influence the energy supply of the organism. L-Carnitine is synthesized exclusively in the liver. Hence, we hypothesized that liver disease can influence L-carnitine metabolism. OBJECTIVES: The goal of this study was to compare plasma L-carnitine concentrations in dogs with different liver diseases of differing severity with the plasma L-carnitine concentrations of healthy dogs. METHODS: Sixteen dogs with inflammatory liver disease and 12 dogs with liver neoplasia were included in the study. Liver disease was diagnosed by clinical chemistry, ultrasonography, and histology of liver biopsy specimens. L-Carnitine concentration was measured in plasma samples using mass spectrometry, and compared among groups using unpaired Student's t-tests. RESULTS: Compared with healthy controls (24.4 +/- 8.4 micromol/L), the plasma L-carnitine concentration in dogs with liver disease (44.2 +/- 23.7 micromol/L) was significantly higher (P<.0001). The difference in L-carnitine concentration between dogs with moderate (n=8; 33.6 +/- 13.7 micromol/L) and severe (n=8; 57.4 +/- 22.9 micromol/L) hepatitis was also significant (P=.02). No difference in plasma L-carnitine concentration was found between dogs with hepatitis and those with liver tumors. CONCLUSIONS: Liver disease in dogs was accompanied by elevated plasma L-carnitine concentration. The severity of hepatitis appears to influence L-carnitine concentration.     

Hemostatic changes in dogs with naturally occurring sepsis

Sepsis is a frequent source of morbidity and mortality in critically ill patients. The goal of this case control study was to measure hemostatic changes in dogs with naturally occurring sepsis. Blood was collected within 24 hours of admission from 20 dogs that fulfilled the criteria for sepsis. Sepsis was defined as histologic or microbiological confirmation of infection and 2 or more of the following criteria: hypo- or hyperthermia, tachycardia, tachypnea, or leukopenia, leukocytosis, or > 3% bands. Culture and sensitivities were performed on appropriate samples from all septic dogs. Twenty-eight control dogs were enrolled on the basis of normal results of physical examination, CBC, serum biochemistry, and coagulation profile. Plasma samples were analyzed for prothrombin time (PT), partial thromboplastin time (PTT), fibrin(ogen) degradation products (FDP), D-dimer (DD) concentrations, antithrombin (AT) activity, and protein C (PC) activity. Data were compared between groups by chi-square or independent t-tests. PC (P < .001) and AT (P < .001) activities were significantly lower in dogs with sepsis compared to controls. Dogs with sepsis had significantly higher PT (P = .007), PTT (P = .005), D-dimer (P = .005), and FDP (P = .001) compared to controls. Platelet counts were not significantly different between groups. Ten of the 20 septic dogs (50%) died, but no association was identified between any of the measured variables and outcome. These findings are consistent with previous studies in animals with experimentally induced disease and in clinical studies of humans. On the basis of these results, further investigation of the role of AT and PC in canine sepsis is warranted.     

Anti-insulin antibodies in dogs with naturally occurring diabetes mellitus

The presence of anti-insulin antibodies was determined by ELISA in serum samples from 30 diabetic dogs receiving bovine insulin therapy and 30 normoglycaemic dogs. Twenty of the diabetic dogs had significant reactivity to both bovine (heterologous) and porcine (homologous) insulin compared to control dogs. In contrast there was no significant difference between the two populations in reactivity to canine distemper virus (CDV) or canine thyroglobulin. The high degree of correlation between anti-bovine insulin and anti-porcine insulin antibodies suggested cross-reactivity which was confirmed by performing a competition ELISA, with antibody binding to bovine insulin inhibited by pre-incubating serum with porcine insulin. The insulin B-chain, rather than the A-chain was the most reactive component of the insulin molecule although in some cases, diabetics with antibody reactivity to whole insulin protein showed minimal reactivity to the individual subunits. The data suggest that treatment of diabetic dogs with bovine insulin can lead to anti-insulin antibody production. These antibodies cross-react with homologous insulin and recognise conformational as well as linear epitopes.     

Plasma antioxidant capacity in dogs with naturally occurring heart diseases

The aim of the study was to compare the plasma levels of antioxidants by measuring total antioxidant activity (TAS) and ferric reducing ability of the plasma (FRAP) in healthy dogs and in those that are suffering from dilated cardiomyopathy (DCM) or from mitral endocardiosis (ME). Dogs with echocardiographically diagnosed ME (10 dogs) as well as DCM (23 dogs) were sampled. Of dogs with DCM, eight having DCM with sinus rhythm (SR) were included in the DCM-SR group and 15 having DCM with atrial fibrillation (AF) in the DCM-AF group. Total antioxidant levels measured by TAS assay differed neither significantly between the cardiac patients and the control group nor between the heart disease groups. Ferric reducing ability of the plasma in animals with cardiac disease was significantly higher than in the control animals, and the difference was also significant in between the two DCM groups. However, the differences between the antioxidant levels of the DCM and ME groups did not reach significance in none of the antioxidant (TAS and FRAP) tests. Summarizing the results of this study it can be concluded that there is an increased antioxidant reactivity detected by the FRAP, but not by the TAS assay in the blood of dogs with naturally occurring cardiac disorders. The magnitude of this increase seems to be more affected rather by the severity of the cardiac insufficiency and/or by the heart rate or rhythm disorder than by the underlying heart disease itself.     

Kidney transplantation in dogs with naturally occurring end-stage renal disease

Renal allografts were performed between unrelated donors and 15 dogs with naturally occurring end-stage renal disease. Donor selection was based on compatible dog erythrocyte antigen typing and cross-matching. An immunosuppressive protocol consisting of rabbit antidog antithymocyte serum, cyclosporin-A, azathioprine, and prednisone was used to control postoperative rejection of the donated kidney. Although seven animals died because of technical failures or rejection episodes, a median survival time of eight months has been achieved, with two dogs living for longer than five years after surgery. Long-term survivors have died from a variety of problems not related to renal allograft rejection.     

Escherichia coli pyometra induces transient glomerular and tubular dysfunction in dogs

Background: Pyometra in dogs has been associated with renal injury. Hypothesis: Examine pyometra‐related nephropathy by evaluating novel renal biomarkers. Animals: Twenty‐five dogs with Escherichia coli pyometra. Fourteen clinically healthy bitches of comparable age. Methods: Prospective study. Urinary biomarkers determined by immunoassays (uIgG, uCRP, uAlb, uRBP, uTXB₂) or colorimetric test (uNAG) with results normalized to urine creatinine concentration. Nonparametric Mann‐Whitney U‐test and Wilcoxon's signed‐rank test used to compare healthy dogs and dogs with pyometra, and dogs with pyometra at initial and follow‐up examination. Results: Urinary biomarkers (median, range) significantly increased in dogs with pyometra (uIgG/Cr: 169.7 mg/g, 4.8–1052.9; uCRP/Cr: 0.260 mg/g, 0.006–3.030; uAlb/Cr: 89.5 mg/g, 8.8–832.7; uRBP/Cr: 1.66 mg/g, 0.05–21.44; uNAG/Cr: 5.8 U/g, 1.6–27.7; uTXB₂/Cr: 15.3 μg/g, 3.2–139.6) compared with healthy bitches (uIgG/Cr: 3.4 mg/g, 0.6–8.9; uCRP/Cr: below detection limit; uAlb/Cr: 17.5 mg/g, 1.3–166.3; uRBP/Cr: 0.13 mg/g, 0.02–0.44; uNAG/Cr: 2.4 U/g, 1.4–7.4; uTXB₂/Cr: 2.4 μg/g, 1.2–4.7) (P < .001). Six months after ovariohysterectomy, urinary biomarkers in pyometra group (uIgG/Cr: 4.7 mg/g, 1.5–99.8; uCRP/Cr: below detection limit; uAlb/Cr: 13.9 mg/g, 2.1–471.2; uRBP/Cr: 0.05 mg/g, 0.02–0.32; uNAG/Cr: 1.6 U/g, 0.9–3.3; uTXB₂/Cr: 3.3 μg/g, 1.0–6.9) were significantly lower than before surgery (P < .01), and not significantly different to those of healthy dogs (P > .05). Conclusion and Clinical Importance: Pyometra‐related renal dysfunction affects the nephron both at glomerular and proximal tubular level and is a transient process in most dogs with E. coli pyometra.     

Pituitary–adrenal axis function in dogs with neoplasia*

Adrenocorticotropic hormone (ACTH) stimulation tests were done in healthy and tumour‐bearing dogs. In the tumour‐bearing dogs, plasma endogenous ACTH (eACTH) concentration was measured and adrenal gland size was assessed ultrasonographically. Measurements in the tumour‐bearing dogs were taken prior to therapy. No difference existed in basal or ACTH‐stimulated cortisol concentration between tumour‐bearing and healthy dogs. No difference existed in eACTH concentration between dogs with non‐haematopoietic neoplasia (NHN) and lymphoma. However, of 20 dogs with lymphoma, 15% had increased basal serum cortisol concentration, 5% had an exaggerated response to ACTH and 5% had an increased eACTH concentration. Of 15 dogs with NHN, 20% had increased basal cortisol concentration, 7% had an exaggerated ACTH response and no dogs had an increased eACTH concentration. Of the dogs with lymphoma and NHN, 5 and 13%, respectively, had decreased basal cortisol concentrations; 20% of dogs with lymphoma and 13% with NHN had a subnormal ACTH response. eACTH levels were below the reference range in 10% of dogs with lymphoma and 7% with NHN. Overall, 10 adrenal glands were enlarged in seven dogs, five with lymphoma and two with NHN. The clinical significance of these findings remains to be determined.