Blood plasma concentrations of oestradiol-17beta,testosterone and testosterone/oestradiol ratio in dogs with neoplastic and degenerative testicular diseases

Oestradiol-17beta and testosterone blood plasma concentrations were measured in dogs with Leydig-cell tumours (n=20), Sertoli-cell tumours (n=6), seminomas (n=9), unilateral inguinal cryptorchidism (n=7), abdominal cryptorchidism (n=9, one bilateral), degenerate scrotal testicles (n=6, two bilateral), and animals with normal scrotal testicles (n=20). The testosterone/oestradiol ratio (testosterone concentration [ng/mL]x100/oestradiol concentration [pg/mL]) was calculated.A considerably higher oestradiol concentration was found in dogs with Sertoli-cell tumours (29.0, 14.4-48.3 pg/mL; median, minimum-maximum; P=0.0256, Mann-Whitney test) and lower oestradiol levels were found in animals with seminomas (12.0, 3.4-17.6 pg/mL; P=0.0025) compared to the healthy control group (18.0, 8.6-31.5 pg/mL). Testosterone concentration was decreased in dogs with Sertoli-cell tumours (0.08, 0.03-0.77 ng/mL) when compared to the control group (1.95, 0.05-3.70 ng/mL; P=0.0012). Testosterone/oestradiol ratios differed from the control (9.6, 0.58-35.8) only in dogs with Sertoli-cell tumours (0.32, 0.06-2.80; P=0.0005). Clinical signs of feminization were observed in five dogs with Sertoli-cell tumour and one dog with a Leydig-cell tumour, and were more often associated with decreased testosterone/oestradiol ratios than with an increased oestradiol-17beta concentration.     

Investigation of serum survivin in dogs suffering from cancer: a multicenter study

BackgroundIn contrast to human medicine, only a small number of serum tumor markers are established in veterinary medicine even though they are a non-invasive diagnostic tool.ObjectivesThis study examined whether survivin could be suitable as a potential canine serum tumor marker.MethodsThis study measured the serum survivin concentrations of dogs with mammary tumors (n = 33), squamous cell carcinoma (n = 9), soft-tissue sarcoma (n = 18) and multicentric lymphoma (n = 22), using a commercially available, competitive immunoassay kit (BlueGene). The serum survivin concentrations were compared with those of a healthy control group (n = 20) and a control group of dogs with non-neoplastic diseases (n = 17).ResultsDogs with malignant tumors had serum survivin concentrations between 15 and 5,906 pg/mL (median, 72 pg/mL), those in the healthy group ranged from 7 to 99 pg/mL (median, 21 pg/mL) and those in the group of dogs suffering from non-neoplastic diseases from 15 to 93 pg/mL (median, 42 pg/mL). The differences in the survivin concentrations between the healthy dogs and dogs with malignant tumors and between the dogs with non-neoplastic diseases and those with malignant tumors were significant (p < 0.001 and p = 0.006, respectively).ConclusionsThe serum survivin concentrations in dogs with malignant tumors, with some exceptions, are higher than in dogs with benign tumors and dogs that do not suffer from a malignancy. Therefore, survivin can provide information on the presence of malignant tumors and be used as a tumor marker in dogs.     

Detection of serum alpha-fetoprotein in dogs with naturally occurring malignant neoplasia

Serum alpha-fetoprotein (AFP) concentrations were determined, by use of an automated microparticle enzyme-linked immunoassay (MEIA), in 16 control dogs and 48 dogs with previously untreated, histologically confirmed, naturally occurring neoplasia (17 dogs with lymphoma and 31 dogs with nonhematopoietic malignancies, 13 dogs with carcinomas, 18 dogs with sarcomas). Mean serum AFP concentrations for untreated dogs with lymphoma, for dogs with sarcomas, and for dogs with carcinomas were not significantly different from the mean serum AFP concentration for the 16 untreated control dogs. Mean serum AFP concentration for dogs with transitional cell carcinoma (n=7) was not significantly different from the mean serum AFP concentration for the control dogs. It has been shown previously by others that a mean serum AFP concentration > 225 ng/mL is suggestive of a hepatic malignancy (e.g., hepatocellular carcinoma, lymphoma). In our study, all 48 dogs had a normal complete blood count, serum biochemical analysis, and urinalysis. Only one of the 48 dogs was found to have a serum AFP concentration > 225 ng/mL. Later evaluation of this dog confirmed hepatic involvement with lymphoma. AFP can be detected in the serum of dogs with naturally occurring tumors using the MEIA technique. A serum AFP concentration above that observed in normal dogs is not a common finding in dogs with naturally occurring neoplasia; however, we confirmed that a serum AFP concentration > 225 ng/mL, with or without evidence of a serum biochemical abnormality, may suggest primary and/or secondary hepatic involvement with a neoplastic disease and may warrant an adjustment in clinical stage and prognosis. A prospective diagnostic and therapeutic evaluation of dogs, with naturally occurring tumors having an elevated serum AFP concentration would determine the validity of this conclusion.     

Polycythemia vera in a cat with cardiac hypertrophy

Polycythemia vera, a rare and poorly documented disease in cats, was diagnosed in a 4-year-old domestic shorthair cat admitted because of seizures. The diagnosis was made on the basis of high PCV, normal serum erythropoietin concentration (as determined by bioassay, using rabbit bone marrow cells), and elimination of secondary polycythemia as a diagnosis. Cardiac hypertrophy, which might have been secondary to blood hyperviscosity, also was diagnosed. The cat has been treated by periodic phlebotomy and has been without clinical signs of disease for more than 20 months.     

Susceptibility of bacteria from feline and canine urinary tract infections to doxycycline and tetracycline concentrations attained in urine four hours after oral dosage

OBJECTIVES: To measure urinary concentrations of doxycycline in cats and dogs and tetracycline in dogs 4 h after conventional oral dosing and determine whether these antibiotics were present in sufficient concentrations to be effective against common feline and canine urinary tract pathogens as assessed in vitro by Epsilometer and disc diffusion antimicrobial susceptibility methods. DESIGN: A prospective study involving oral administration to clinically normal cats and dogs of doxycycline or tetracycline (dogs only) and culture of bacteria from dogs and cats with urinary tract infections to determine their susceptibility to both doxycycline and tetracycline in vitro. PROCEDURE: In the first study, nine cats and eight dogs were administered doxycycline monohydrate (5 mg/kg every 12 h) and a further eight dogs were administered tetracycline hydrochloride (20 mg/kg every 8 h) for 72 h. Blood was collected at 2 and 4 h, and urine at 4 h, after the last dose. The concentration of each agent in serum and urine was determined by modified agar diffusion. In the second study, 45 urine samples from cats and dogs with urinary tract infections were cultured. Every bacterial isolate was tested in vitro using both Epsilometer (doxycycline and tetracycline) and disc diffusion (doxycycline, tetracycline or amoxycillin-clavulanate) tests. RESULTS: Serum doxycycline concentrations in sera of cats and dogs at 2 h were 4.2 +/- 1.0 mg/mL and 3.4 +/- 1.1 mg/mL, respectively. The corresponding concentrations at 4 h were 3.5 +/- 0.7 mg/mL and 2.8 +/- 0.6 mg/mL. Urinary doxycycline concentrations at 4 h (53.8 +/- 24.4 mg/mL for cats and 52.4 +/- 24.1 mg/mL for dogs) were substantially higher than corresponding serum values. Serum tetracycline concentrations in dogs at 2 and 4 h, and in urine at 4 h, were 6.8 +/- 2.8, 5.4 +/- 0.8, 144.8 +/- 39.4 mg/mL, respectively. Most of the urinary tract pathogens (35/45) were susceptible to urinary concentrations of doxycycline and 38/45 were susceptible to tetracycline. In contrast 41/45 of all isolates were susceptible to amoxycillin-clavulanate. CONCLUSION: This is the first report of urinary concentrations of doxycycline after conventional oral administration. Concentrations attained in the urine of normal cats and dogs were sufficient to inhibit the growth of a significant number of urinary tract pathogens and thus doxycycline may be a useful antimicrobial agent for some urinary tract infections.     

Serum concentrations of immunoglobulins G, A, and M in dogs with neoplastic disease

The concentrations of the three major classes of immunoglobulins (Ig) were determined in canine serum by single radial immunodiffusion against calibrated standards. Serum samples were collected from 121 dogs categorized into 3 groups: normal dogs (n = 34), those with lymphosarcoma (n =41), and those with malignant, solid neoplasms other than lymphosarcoma (n = 46). The mean value for serum IgM concentration in the group of dogs with lymphosarcoma was significantly (P less than or equal to 0.02) higher than was the mean IgM concentration of the normal dogs. Dogs with neoplasms other than lymphosarcoma had significantly increased serum concentrations of IgG and IgM antibodies. There was no significant difference in serum IgA concentration among the three groups. A wide range of Ig concentrations was in the serum of clinically normal dogs, as well as in dogs with neoplastic diseases. Although individual dogs with neoplasms had low serum Ig concentrations, the 81 dogs with neoplastic disease were generally able to synthesize Ig.     

Serum Fructosamine Concentration as an Index of Glycemia in Cats With Diabetes Mellitus and Stress Hyperglycemia

The purpose of this study was to evaluate fructosamine concentrations in clinically healthy cats, sick cats with stress hyperglycemia, and untreated diabetic cats to determine the usefulness of this test in diagnosing diabetes mellitus in cats, and in differentiating the disease from stress-induced hyperglycemia. In addition, we evaluated if the degree of glycemic control in cats treated for diabetes influenced their serum fructosamine concentrations. In the 14 sick cats with stress hyperglycemia, the median serum fructosamine concentration (269 μmol/L) was not significantly different from the median value in the 26 clinically normal cats (252 μmol/L). Two of the 14 cats with stress hyperglycemia (14.3%) had serum fructosamine concentrations above the upper limit of the reference range (175 to 400 μmol/U; on the basis of these results, the test specificity was calculated as 0.86. In 30 cats with untreated diabetes mellitus, the median serum fructosamine concentration was 624 μmol/L, markedly higher than the value in either the normal cats or the cats with stress hyperglycemia. All but 2 of the 30 untreated diabetic cats (6.7%) had serum fructosamine concentration above the upper limit of the reference range; on the basis of these results, the sensitivity of serum fructosamine concentration as a diagnostic test for diabetes mellitus was 0.93. When 30 diabetic cats receiving treatment were divided into 3 groups according to their response to treatment (ie, poor, fair, and good), the 16 cats that had a good response to treatment had significantly lower serum concentrations of both glucose and fructosamine compared with cats that had either a fair or poor response to treatment. A significant correlation (r_s= .70, n = 100, P < .001) was found between serum concentrations of glucose and fructosamine. Results of this study indicate that quantification of serum fructosamine concentration is a meaningful test for the diagnosis of diabetes, for differentiating diabetes from stress hyperglycemia; and for monitoring the metabolic control in treated diabetic cats.     

Immunoglobulin deficiency in Cavalier King Charles Spaniels with Pneumocystis pneumonia

Serum concentrations of immunoglobulin G (IgG), IgM, and IgA were measured in 9 Cavalier King Charles Spaniels with pneumonia caused by Pneumocystis sp that were examined at 4 veterinary surgeries in the United Kingdom (UK) between September 2001 and November 2002. Pneumocystis pneumonia was confirmed in all dogs by visualization of the organism in bronchoalveolar lavage fluid or a transthoracic lung aspirate. Two dogs had a history of demodicosis. Immunoglobulin concentrations also were measured in breed-and age-matched dogs sampled over the same period. IgG concentrations were significantly (P = .000) lower in the affected dogs (median 3.2 mg/mL) than in the control dogs (median 8.5 mg/mL). IgM concentrations were significantly (P = .002) higher in the affected dogs (median 1.95 mg/mL) than in the control dogs (median 1.12 mg/mL). One affected dog had no change in IgG concentration more than 3 months after resolution of infection or vaccination, but did have reduction in IgM concentration after resolution of infection and vaccination. Control dogs had low serum IgG and IgM concentrations, compared with the reference interval for all dogs. Lymphocyte count in blood was normal or high in 7 of 8 affected dogs. The results of this study suggest that there is a defect in immunity in Cavalier King Charles Spaniels that underlies the susceptibility of these dogs to pneumocystosis. Further studies are indicated to elucidate the mechanisms behind the defect, the prevalence within the breed, and the potential mode of inheritance of the problem.     

Free light-chain proteinuria and normal renal histopathology and function in 11 dogs exposed to Lleishmania infantum, Ehrlichia canis, and Bbabesia canis

The purpose of this retrospective study was to investigate the relationship among proteinuria consisting of immunoglobulin free light chains (FLCs), renal histopathologic findings, and routine markers of renal function in 11 dogs exposed to Leishmania infantum (n = 8), Ehrlichia canis (n = 2), and Babesia canis (n = 1). FLC proteinuria was suspected based on identification of a 22- to 27-kDa band by sodium dodecyl sulfate-agarose gel electrophoresis (SDS-AGE) and later confirmed by immunofixation electrophoresis. SDS-AGE identified an isolated band of 22-27 kDa in 8 dogs, whereas the remaining 3 had a 22- to 27-kDa band and an additional band of 67-72 kDa. The median urine protein-to-urine creatinine ratio was 0.37 (range, 0.11-2.24) and increased ratios were found in 6 dogs (54.5%) (reference value, <0.7). All dogs underwent histologic examination of renal percutaneous biopsy specimens and determination of serum creatinine and urea concentrations. Tissue samples for light microscopy were stained with hematoxylin-eosin, periodic acid-Schiff, Goldners trichrome, and methenamine silver. In the study group, the glomerular tufts, mesangium, tubulointerstitium, and vessels appeared unaffected. The median serum creatinine concentration in these 11 dogs was 1.3 mg/dL (range, 0.8-1.5 mg/dL; reference range, 0.6-1.5 mg/dL), whereas the concentration for urea was 28 mg/dL (range, 22-52 mg/dL; reference range, 20-50 mg/dL). All dogs had normal renal morphology and had normal serum creatinine and urea concentrations, suggesting that immunoglobulin FLC may be detected in the urine of dogs exposed to L. infantum, E. canis, and B. canis without any apparent structural or functional renal derangement.     

Cytologic evaluation of primary and secondary myelodysplastic syndromes in the dog

Myelodysplastic syndromes are a heterogeneous group of acquired primary and secondary alterations of hematopoietic stem cells that result in cytopenias in blood and cytologic features of dysplasia in blood and/or bone marrow. To better understand the cytologic features that would permit differentiation of primary and secondary forms of myelodysplasia, we reviewed 267 consecutive bone marrow reports from dogs. These reports indicated that 34 dogs (12.7%) had dysgranulopoiesis, dyserythropoiesis, and/or dysthrombopoiesis in >10% of granulopoietic cells, erythroid cells, and/or megakaryocytes, respectively. Thirteen dogs had primary myelodysplastic syndromes, and 21 had secondary myelodysplastic syndromes. Of the 13 dogs with primary myelodysplasia, 4 were subclassified as myelodysplastic syndrome with refractory anemia (MDS-RA), and 9 were subclassified as myelodysplastic syndrome with excess blasts (MDS-EB). Secondary conditions associated with dysplasia in the bone marrow included malignant lymphoma (n = 5), myelofibrosis (n = 3), immune-mediated thrombocytopenia (n = 4), immune-mediated hemolytic anemia (n = 5), multiple myeloma with melphalan administration (n = 1), pyometra with estrogen administration (n = 1), polycythemia vera (n = 1), and thrombopathia (n = 1). MDS-RA was characterized by <5% myeloblasts in bone marrow, normal granulocyte maturation ratio, increased erythroid maturation ratio, and dysplastic changes in >15% of erythroid cells. MSD-EB was characterized by >/=5% myeloblasts in bone marrow, high granulocyte maturation and erythroid maturation ratios, >/=32% dysplastic granulocytes, and the presence of small atypical immature myeloid cells. Secondary myelodysplastic syndromes were characterized by <5% myeloblasts in bone marrow, variable granulocyte maturation and erythroid maturation ratios, and variable dysplastic features. These results indicate that morphology alone cannot be used to distinguish primary and secondary myelodysplastic syndromes in dogs.     

Evaluation of IGF-I levels and serum protein profiles of diabetic cats and dogs

In this study, we measured the insulin-like growth factor (IGF)-I levels and evaluated the serum protein profiles of diabetic, insulin-treated, and healthy cats and dogs. The total IGF-I concentrations were 33.74 ± 3.4 ng/mL for normal, 25.8 ± 4.5 ng/mL for diabetic, and 180.4 ± 31.4 ng/mL for insulin-treated cats. IGF-I concentrations were 46.4 ± 6.6 ng/mL for normal, 25.1 ± 4.1 ng/mL for diabetic, and 303.0 ± 61.3 ng/mL for insulin-treated dogs. Total serum protein profiles were analyzed by SDS-PAGE. Fourteen bands ranging from 25 to 240 kDa in size were observed for cats, and 17 bands ranging from 25 to 289 kDa were observed for dogs. The densities of the bands differed among control, diabetic, and insulin-treated animals. In conclusion, we found that serum protein profiles and IGF-I concentrations were altered in both diabetic and insulin-treated animals. When judiciously interpreted in the light of other clinical and laboratory data, the techniques used in our study provide a valuable modality for measuring the severity of diabetes mellitus in dogs and cats.     

C-reactive protein in dogs

Serum concentrations of C-reactive protein (CRP) in dogs with various diseases or undergoing various procedures were measured by specific immunoassay. In 20 healthy dogs from various sources, values were all less than 5 mg/L, but in 22 healthy dogs from a single source, values ranged from less than 5 mg/L in 14 dogs and from 8 to 67 mg/L in 8 dogs. Increased concentrations of serum CRP were attained 24 hours after injection of casein (n = 9; median 188 mg/L), ovariohysterectomy (n = 11; median, 144 mg/L), or elective, nonacute orthopedic surgery (n = 10; median, 83 mg/L). After inoculation of Leptospira interrogans serovar canicola (n = 5), the behavior of serum CRP as an acute-phase reactant provided a sensitive and precise objective reflection of in vivo response. The CRP concentration in random single-serum samples from 73 dogs with other inflammatory and noninflammatory disorders ranged from normal (less than 5 mg/L) to 246 mg/L and generally correlated with the extent and activity of disease.     

Endostatin and vascular endothelial growth factor concentrations in healthy dogs, dogs with selected neoplasia, and dogs with nonneoplastic diseases

To evaluate the relationship between endostatin and vascular endothelial growth factor (VEGF) in cancers of dogs, circulating concentrations of these 2 tumor-associated markers were measured prospectively in healthy dogs (n = 44), dogs with tumors (n = 54), and dogs with nonneoplastic diseases (n = 42 for endostatin; n = 16 for VEGF). A canine-directed enzyme-linked immunosorbent assay kit was used for determination of endostatin, and a human-directed kit was validated for detection of canine VEGF. Concentrations of endostatin for all dogs were 28-408 ng/mL. Increasing serum endostatin concentration was associated with increasing age (P = .0396). Concentrations of endostatin were not different among groups of dogs (P = .1989) when adjusted for age. Mean endostatin concentrations for all dogs were higher in dogs (P = .0124) with detectable VEGF concentrations. Endostatin concentrations, when corrected for age, were related to decreasing PCV (P = .032) but not white blood cell count (P = .225) or platelet count (P = .1990). Measurable VEGF (> or = 2.5 pg/mL) was detected in 3 (7.0%) of 43 healthy dogs. Dogs with tumors had detectable VEGF in 24 (44%) of 54 dogs, with concentrations ranging from 2.5-274 pg/mL; only 1 dog with a nonneoplastic disease process had detectable VEGF. VEGF concentrations for all dogs after correcting for age, endostatin, and disease categories were associated with increased white blood cell count (P = .0032) and platelet counts (P = .0064) and decreased PCV (P = .0017). Linkage between increased endostatin and VEGF concentrations suggests that similar factors may influence concentrations of these markers. Further evaluation of endostatin and VEGF associations in dogs with tumors may provide information on the extent and progression of the disease.     

Prospective clinical evaluation of serum cardiac troponin T in dogs admitted to a veterinary teaching hospital

The purpose of this study was to measure serum cardiac troponin T (cTnT) with a commercially available human enzyme-linked immunoassay (ELISA) test in various groups of dogs, including those undergoing doxorubicin chemotherapy. Serum samples were obtained from 6 groups of dogs: (1) normal adult dogs (n = 15); (2) dogs with asymptomatic dilated cardiomyopathy (n = 5); (3) dogs with congestive heart failure (n = 10); (4) dogs with untreated neoplasia (n = 20); (5) dogs with skeletal muscle trauma (n = 10); and (6) dogs with neoplasia receiving doxorubicin chemotherapy (n = 4). One serum sample was obtained from each of the normal dogs, those with asymptomatic cardiomyopathy, those with congestive heart failure, and those with untreated neoplasia. Serum samples were obtained serially from the dogs that were undergoing doxorubicin chemotherapy; samples were collected before doxorubicin (30 mg/m2) administration and then 1, 5, 7, and 14 days after administration throughout 6 cycles for a cumulative total dose of 180 mg/m2. All normal dogs, dogs with untreated neoplasia, and dogs with asymptomatic dilated cardiomyopathy had cTnT concentrations below the lower limits of detection for the assay used (<0.05 ng/mL). Detectable concentrations of cTnT were found in 3 dogs with congestive heart failure and in 2 dogs with skeletal muscle trauma. Detectable concentrations also were found in both dogs that had received 180 mg/m2 of doxorubicin. We conclude that dogs with congestive heart failure and those with skeletal muscle trauma and dogs with neoplasia receiving high-dose doxorubicin chemotherapy may have increased serum cTnT concentration, which may be suggestive of myocardial damage.     

Prospective clinical evaluation of an ELISA B-type natriuretic peptide assay in the diagnosis of congestive heart failure in dogs presenting with cough or dyspnea

BACKGROUND: B-type natriuretic peptide (BNP) is increased in dogs with congestive heart failure (CHF). HYPOTHESIS: The purpose of this study was to evaluate the clinical utility of a novel canine-specific enzyme-linked immunosorbent assay of BNP for the diagnosis of CHF in dogs presenting with either cough or dyspnea. ANIMALS: Three hundred and thirty dogs from 2 large university teaching hospitals. METHODS: We prospectively measured plasma BNP concentrations in 3 groups of dogs: (1) normal adult dogs (n = 75), (2) dogs with asymptomatic heart disease (n = 76), and (3) dogs with cough or dyspnea (n = 179). The final diagnosis of dogs with cough or dyspnea and the severity of CHF (International Small Animal Cardiac Health Council Heart Failure Classification [ISACHC]) were determined by medical record review by a study cardiologist who was blinded to the results of the BNP assay. RESULTS: Dogs with CHF had a higher median BNP concentration (24.6 pg/mL) than dogs with noncardiac causes of cough or dyspnea (2.6 pg/mL) (P < .0001). The area under the curve was 0.91 for the receiver operating curve analysis of the diagnostic accuracy of the BNP measurement to differentiate CHF from other causes of cough or dyspnea. The median BNP concentrations in dogs were 3.0 pg/mL with ISACHC I, 17.8 pg/mL with ISACHC II, and 30.5 pg/mL with ISACHC III. (P < .0001) CONCLUSION AND CLINICAL IMPORTANCE: Measurement of BNP is useful in establishing or in excluding the diagnosis of CHF in dogs with cough or dyspnea. B-type natriuretic peptide concentrations rose significantly as a function of severity of CHF.     

Glomerular Filtration Rate and Renal Volume in Dogs with Congenital Portosystemic Vascular Anomalies before and after Surgical Ligation

Glomerular filtration rate (GFR) and renal volume were evaluated in dogs with confirmed portosystemic vascular anomalies (PSVA) before and after surgical ligation of their PSVA. Pre- and postligation CBC, serum biochemistry, urinalysis, abdominal ultrasonography with measurement of renal volume, and per rectal scintigraphy were performed to document resolution of abnormalities consistent with portosystemic shunting. GFR was estimated by plasma 99mTc-diethylenetriaminepentaacetic acid (99mTc-DTPA) clearance before (n = 21) and after (n = 12) surgical correction of PSVA. Preligation 99mTc-DTPA GFR was increased (median, 5.64 mL/minute/kg; range, 3.53-8.49 mL/minute/kg; reference range, 2.83-4.47 mL/minute/kg) in 81% (17/21) of dogs. Postligation 99mTc-DTPA GFR decreased in all 12 evaluated dogs (median change = -42%; P < .001). Preligation renal volume was above the reference range for the left and right kidneys in 71% (10/14) and 69% (11/16) of dogs evaluated, respectively. Right renal volume decreased significantly (n = 5; median change, -45%; P = .03) after surgical ligation of PSVA. These findings document increased GFR and renal volume in dogs with PSVA, which may explain in part the low blood urea nitrogen and serum creatinine concentrations encountered in these dogs. Knowledge of changes in GFR associated with PSVA ligation may prove helpful in the anesthetic, drug, and dietary management of affected dogs.     

Serum zinc, chromium, and iron concentrations in dogs with lymphoma and osteosarcoma

We compared serum concentrations of zinc, chromium, and iron in dogs with cancer to those of normal dogs. Dogs with lymphoma (n = 50) and osteosarcoma (n = 52) were evaluated. Dogs with lymphoma had significantly lower (P = .0028) mean serum zinc concentrations (mean +/- SD; 1.0 +/- 0.3 mg/L) when compared to normal dogs (1.2 +/- 0.4 mg/L). Dogs with osteosarcoma also had lower mean serum zinc concentrations (1.1 +/- 0.4 mg/L), but this difference was not significant (P = .075). Serum chromium concentrations were significantly lower in dogs with lymphoma (2.6 +/- 2.6 microg/L, P = .0007) and osteosarcoma (2.4 +/- 3.1 microg/L, P = .0001) compared to normal dogs (4.7 +/- 2.8 microg/L). Serum iron concentrations and total iron-binding capacity were significantly lower in dogs with lymphoma (110.8 +/- 56.7 microg/dL, P < .0001, and 236.6 +/- 45.6 microg/dL, P < .0001, respectively) and osteosarcoma (99.6 +/- 49.3 microg/dL, P < .0001, and 245.0 +/- 43.8 microg/dL, P = .0011, respectively) when compared to normal dogs (175.1 +/- 56.7 microg/dL and 277.1 +/- 47.4 microg/dL). Mean ferritin concentration was significantly higher in dogs with lymphoma (1291.7 +/- 63.0 microg/L) than in normal dogs (805.8 +/- 291.1 microg/L, P < .0001) and dogs with osteosarcoma (826.5 +/- 309.2 microg/L, P < .0001). Further investigation is needed to explore the clinical significance of these mineral abnormalities in dogs with cancer.     

Plasma Taurine Concentrations in Normal Dogs and in Dogs With Heart Disease

Plasma taurine concentrations were determined in 76 dogs with dilated cardiomyopathy (DCM), 28 dogs with acquired valvular disease (AVD), and 47 normal (control) dogs. The data were collected at 2 referral centers. The Animal Medical Center, New York, NY (AMC), and the University of California, Davis (UCD), and the studies were conducted independently. Different anticoagulants (sodium citrate at AMC and lithium heparin at UCD) were used to collect the plasma samples. Paired analysis of samples showed a significant difference in plasma taurine concentrations, depending on the anticoagulant used. Consequently, results from each clinic were analyzed separately. Plasma taurine concentrations were significantly higher in dogs with AVD (median, 133 nmol/mL; range, 25 to 229 nmol/mL) than in control dogs (median, 63 nmol/mL; range 44 to 224 nmol/mL) and dogs with DCM (median, 72 nmol/mL; range, 1 to 247 nmol/mL) at AMC (P= .001). The number of dogs with AVD at UCD was too small to draw meaningful conclusions. At UCD, the median plasma taurine concentration was 98 nmol/mL (range, 28–169 nmol/mL) in dogs with AVD, 75 nmol/mL (range, 0.1–184 nmol/mL) in dogs with DCM, and 88 nmol/mL (range 52–180 nmol/mL) in control dogs. There were no significant differences in plasma taurine concentrations between dogs with DCM and the control dogs at either hospital. Congestive heart failure and administration of cardiac medication had no significant effect on plasma taurine concentrations. Plasma taurine concentration was low (<25 nmol/mL) in 17% (13/76) of the dogs with DCM. Seven of the 13 dogs with low plasma taurine concentrations were Cocker Spaniels or Golden Retrievers. It was concluded that most dogs with DCM do not have low plasma taurine concentrations. However, certain breeds or individual dogs may have low plasma taurine concentrations in association with DCM. Whether this association is causal or not is unknown. The significance of the high plasma taurine concentrations in dogs with AVD is also unknown.     

ULTRASONOGRAPHIC DIAGNOSIS OF PORTOSYSTEMIC SHUNTING IN DOGS AND CATS

The value of ultrasonography was evaluated in 85 dogs and 17 cats presented with a clinically suspected portosystemic shunt (PSS). A PSS was confirmed in 50 dogs and nine cats (single congenital extrahepatic in 42, single congenital intrahepatic in 11, and multiple acquired in six). Six dogs and one cat had hepatic microvascular dysplasia, and 29 dogs and seven cats had a normal portal system. Ultrasonography was 92% sensitive, 98% specific, and had positive and negative predictive values of 98% and 89%, respectively, in identifying PSS, with an overall accuracy of 95%. When a PSS was identified with ultrasonography, extrahepatic, intrahepatic, and multiple acquired PSS could be correctly differentiated in 53/54 patients (98%). The combination of a small liver, large kidneys, and uroliths had positive and negative predictive values of 100% and 51% for the presence of a congenital PSS in dogs. The portal vein/aorta (PV/Ao) and portal vein/caudal vena cava (PV/ CVC) ratios were smaller in animals with extrahepatic PSSs compared with animals with microvascular dysplasia, intrahepatic PSSs and those without portal venous anomalies (P<0.001). All dogs and cats with a PV/Ao ratio of < or = 0.65 had an extrahepatic PSS or idiopathic noncirrhotic portal hypertension. Dogs and cats with PV/Ao and PV/CVC ratios of > or = 0.8 and > or = 0.75, respectively, did not have an extrahepatic PSS. Reduced or reversed portal flow was seen in four of four patients with multiple acquired PSSs secondary to portal hypertension. The presence of turbulence in the caudal vena cava of dogs had positive and negative predictive values of 91% and 84%, respectively, for the presence of any PSS terminating into that vein.     

Angiotensin converting enzyme and chymase activity in the feline heart and serum

The feline cardiac and serum angiotensin converting enzyme (ACE) and chymase activities were determined and compared in dogs, and hamsters. In all three species, cardiac chymase activity exceeded ACE activity; however, there were some differences. In cats, left ventricular ACE and chymase activities (0.15 +/- 0.01 and 0.59 +/- 0.1 mU/mg-protein, respectively) were lower than in dogs (0.42 +/- 0.05: p<0.01 and 2.0 +/- 0.4 mU/mg-protein: p<0.01) and hamsters (0.93 +/- 0.06: p<0.001 and 2.1 +/- 0.2 mU/mg-protein: p<0.01); in contrast, serum ACE activities was higher in cats (12.7 +/- 1.0 mU/ml) than in dogs (5.9 +/- 0.6 mU/ml: p<0.001). The relative contribution of chymase (cats: 84.0 +/- 5.1%, dogs: 81.4 +/- 3.4%, and hamsters: 72.6 +/- 5.6 %) to ANG-II formation in the heart was greater than that of ACE in these animals (cats: 10.9 +/- 4.1%, dogs: 11.5 +/- 3.6%, and hamsters: 17.2 +/- 0.8%). These species-specific differences suggest that the efficacy of renin-angiotensin system modulating agents may differ among species.