Hypovitaminosis D in dogs with inflammatory bowel disease and hypoalbuminaemia

Objectives : To compare serum vitamin D metabolites and plasma parathyroid hormone concentrations in dogs with inflammatory bowel disease and normal albumin concentration, dogs with inflammatory bowel disease and hypoalbuminaemia, healthy dogs and hospitalised ill dogs with non‐gastrointestinal illness. Methods : Serum 25 hydroxyvitamin D and 1,25 dihydroxyvitamin D concentrations were measured in 36 healthy dogs, 49 hospitalised ill dogs with non‐gastrointestinal illnesses, 21 dogs with inflammatory bowel disease and normoalbuminaemia and 12 dogs with inflammatory bowel disease and hypoalbuminaemia. Plasma parathyroid hormone and ionised calcium concentrations were measured in a subset of these dogs. Results : Concentrations of serum 25 hydroxyvitamin D were lower in hypoalbuminaemic dogs with inflammatory bowel disease than in the healthy dogs (P<0·001), hospitalised ill dogs (P<0·001) and normoalbuminaemic dogs with inflammatory bowel disease (P<0·001). Dogs with inflammatory bowel disease and hypoalbuminaemia had a higher plasma concentration of parathyroid hormone (P<0·01) and lower plasma concentration of ionised calcium (P<0·001) than hospitalised ill dogs. Dogs with inflammatory bowel disease had a positive correlation between serum 25 hydroxyvitamin D concentrations and serum albumin (P<0·0001), serum calcium (P<0·0001) and plasma ionised calcium (P<0·0005) concentrations. Clinical Significance : Dogs with inflammatory bowel disease and hypoalbuminaemia frequently have ionised hypocalcaemia, high parathyroid hormone and low serum 25 hydroxyvitamin D concentrations. Further studies are indicated to establish the pathogenesis of this disease complication as well as therapeutic strategies to reverse this state.     

Serum concentrations of 1,25-dihydroxycholecalciferol and 25-hydroxycholecalciferol in clinically normal dogs and dogs with acute and chronic renal failure

OBJECTIVE: To compare serum concentrations of 1,25-dihydroxycholecalciferol (1,25-[OH]2D3) and 25-hydroxycholecalciferol (25-[OH]D3) in healthy control dogs and dogs with naturally occurring acute renal failure (ARF) and chronic renal failure (CRF). ANIMALS: 24 control dogs, 10 dogs with ARF, and 40 dogs with CRF. PROCEDURE: Serum concentrations of 1,25-(OH)2D3 were measured by use of a quantitative radioimmunoassay, and serum concentrations of 25-(OH)D3 were measured by use of a protein-binding assay. RESULTS: Mean +/- SD serum concentration of 1,25-(OH)2D3 was 153 +/- 50 pmol/L in control dogs, 75 +/- 25 pmol/L in dogs with ARF, and 93 +/- 67 pmol/L in dogs with CRF. The concentration of 1,25-(OH)2D3 did not differ significantly between dogs with ARF and those with CRF and was in the reference range in most dogs; however, the concentration was significantly lower in dogs with ARF or CRF, compared with the concentration in control dogs. Mean +/- SD concentration of 25-(OH)D3 was 267 +/- 97 nmol/L in control dogs, 130 +/- 82 nmol/L in dogs with ARF, and 84 +/- 60 nmol/L in dogs with CRF. The concentration of 25-(OH)D3 was significantly lower in dogs with ARF or CRF, compared with the concentration in control dogs. CONCLUSIONS AND CLINICAL RELEVANCE: The concentration of 1,25-(OH)2D3 was within the reference range in most dogs with renal failure. Increased serum concentrations of parathyroid hormone indicated a relative deficiency of 1,25-(OH)2D3. A decrease in the serum concentration of 25-(OH)D3 in dogs with CRF appeared to be attributable to reduced intake and increased urinary loss.     

Relationship between plasma iohexol clearance and urinary exogenous creatinine clearance in dogs

The objective of this study was to determine if plasma iohexol clearance, computed by a 1-compartment model defined by 3 plasma samples. was an accurate measure of glomerular filtration rate (GFR) in dogs. Twenty-two adult Beagle dogs of both genders were studied. Ten dogs had intact kidneys, and 12 dogs had surgically reduced renal mass. A bolus injection of iohexol was made, and blood was obtained for plasma iohexol assay after 120, 180, and 240 minutes. Plasma was analyzed for iohexol concentration by means of 3 assay methods: chemical, high-performance liquid chromatography (HPLC), and inductively coupled plasma emission spectroscopy (ICP). Urinary clearance of exogenous creatinine was used to measure GFR for three 30-minute periods occurring between 150 and 240 minutes after iohexol injection. Plasma clearance of iohexol and renal clearance of creatinine were compared by linear regression analysis and by limits of agreement techniques. Plasma iohexol clearance and urinary exogenous creatinine clearance were significantly correlated (chemical R2 = .90; HPLC R2 = .96; and ICP R2 = .96). The 1-compartment iohexol clearance:exogenous creatinine clearance ratios were 1.04 +/- 0.17, 1.05 +/- 0.14, and 1.10 +/- 0.15 for the chemical, HPLC, and ICP methods of assay, respectively, indicating that plasma iohexol clearance slightly overestimated GFR. Assuming a +/- 2 standard deviation interval for error, corrected plasma iohexol clearance measured GFR with +/-34% accuracy for the chemical, +/-26% accuracy for the HPLC, and +/-27% accuracy for the ICP method. These results indicate that plasma iohexol clearance should have utility for detection of renal dysfunction earlier in the course of progressive renal disease than is possible with measurement of plasma creatinine or urea concentrations.     

Effects of chronic renal disease on the transport of vitamin A in plasma and urine of dogs

OBJECTIVE: To determine plasma and urine concentrations of retinol, retinyl esters, retinol-binding protein (RBP), and Tamm-Horsfall protein (THP) in dogs with chronic renal disease (CRD). ANIMALS: 17 dogs with naturally developing CRD and 21 healthy control dogs. PROCEDURE: A diagnosis of CRD was established on the basis of clinical signs, plasma concentrations of creatinine and urea, and results of urinalysis. Concentrations of retinol and retinyl esters were measured by use of reverse-phase high-performance liquid chromatography. Concentrations of RBP and THP were measured by use of sensitive ELISA systems. RESULTS: Dogs with CRD had higher plasma concentrations of retinol, which were not paralleled by differences in plasma concentrations of RBP. Calculated ratio of urinary total vitamin A (sum of concentrations of retinol and retinyl esters to creatinine concentration) and ratio of the concentration of urinary retinyl esters to creatinine concentration did not differ between groups. However, we detected a significantly higher retinol-to-creatinine ratio in the urine of dogs with CRD, which was paralleled by a higher urinary RBP-to-creatinine ratio. Thus, in dogs with CRD, the estimated fractional clearance of total vitamin A, retinol, and RBP was increased. Furthermore, dogs with CRD had a reduced urinary THP-to-creatinine ratio. CONCLUSIONS AND CLINICAL RELEVANCE: Results of this study documented that CRD affects the concentrations of retinol in plasma and urine of dogs. Analysis of the data indicates that measurement of urinary RBP and urinary THP concentrations provides valuable information that can be helpful in follow-up monitoring of dogs with CRD.     

Plasma vascular endothelial growth factor concentrations in healthy dogs and dogs with hemangiosarcoma

Vascular endothelial growth factor (VEGF) is a dimeric glycosylated polypeptide growth factor with potent angiogenic, mitogenic, and vascular permeability-enhancing properties specific for endothelial cells. In humans, VEGF seems to play a major role in tumor growth, and plasma concentrations correlate with tumor burden, response to therapy, and disease progression. This study compared plasma VEGF concentrations in healthy client-owned dogs (n = 17) to dogs with hemangiosarcoma (HSA; n 16). Dogs with HSA were significantly more likely to have detectable concentrations of plasma VEGF (13/17) compared to healthy dogs (1/17; P < .001). The median plasma VEGF concentration for dogs with HSA was 17.2 pg/mL (range, < 1.0-66.7 pg/mL). Plasma VEGF concentrations in dogs with HSA did not correlate with stage of disease or tumor burden, but 1 dog had undetectable VEGF during chemotherapy that subsequently increased with disease progression.     

Evaluation of plasma-ionized magnesium concentration in 122 dogs with diabetes mellitus: a retrospective study

The goal of this study was to evaluate plasma-ionized magnesium (iMg2+) concentration in a large group of dogs with naturally occurring diabetes mellitus and to determine whether dogs with diabetes mellitus have hypomagnesemia, as reported in diabetic humans and cats. Plasma iMg2+ concentrations were retrospectively evaluated at the time of initial examination of 122 diabetic dogs at the Matthew J. Ryan Veterinary Hospital of the University of Pennsylvania. Diabetic dogs were defined as having uncomplicated diabetes mellitus (DM, 78 dogs) diabetic ketoacidosis (DKA, 32 dogs), or ketotic nonacidotic diabetes mellitus (DK, 12 dogs) on the basis of presence or absence of metabolic acidosis or ketonuria. Twenty-two control dogs were used to determine reference values for plasma iMg2+ concentration in healthy dogs. Plasma iMg2+ concentration also was evaluated in 19 nondiabetic dogs with acute pancreatitis because many of the dogs with DKA had concurrent acute pancreatitis. Plasma iMg2+ concentration was significantly higher in dogs with DKA (median 0.41 mmol/L, reference range 0.14-0.72 mmol/L) than in dogs with DM (0.33 mmol/L, 0.17-0.65 mmol/L; P = .0002) or the control group (0.32 mmol/L, 0.26-0.41 mmol/L; P = .006). There were no significant differences between plasma iMg2+ concentrations in dogs with DM or DK compared with control dogs. We conclude that dogs with naturally occurring diabetes mellitus do not have marked hypomagnesemia on initial examination at a tertiary care center.     

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.     

Plasma free cortisol concentrations in dogs with hyperadrenocorticism.

Unbound or free cortisol constitutes a small fraction of total plasma cortisol, but is believed to represent the biologically active portion of this circulating glucocorticoid. We tested the hypothesis that the percentage free cortisol was altered in plasma from dogs with hyperadrenocorticism, which could account for a greater target tissue response to this circulating hormone. The percentage free cortisol in plasma samples from human beings, healthy dogs, and dogs with hyperadrenocorticism was estimated, using centrifugal ultrafiltration-dialysis. Total cortisol concentrations were determined by use of radioimmunoassay. Total cortisol concentrations appeared greater in plasma from human beings than in plasma from either group of dogs. However, the percentage free cortisol was lower in plasma from human beings, resulting in a calculated concentration of free cortisol that was quite similar between plasma from human beings and healthy dogs. Total plasma cortisol concentrations were greater (P less than 0.01) in samples from dogs with hyperadrenocorticism (190 +/- 113 nmol/L; mean +/- SD) than in healthy dogs (102 +/- 85 nmol/L), but the percentage free cortisol was not different between these 2 groups (dogs with hyperadrenocorticism, 16 +/- 9%; healthy dogs, 13 +/- 6%). However, plasma free cortisol concentrations (product of total and the percentage of free cortisol) were greater (P less than 0.01) in samples from dogs with hyperadrenocorticism (36 +/- 41 nmol/L) than in those from healthy dogs (16 +/- 9 nmol/L). Significant (P less than 0.001) positive linear relationships were found between total cortisol concentrations and percentage free cortisol in plasma samples from healthy dogs and dogs with hyperadrenocorticism.(ABSTRACT TRUNCATED AT 250 WORDS)     

Serum and urine concentrations of trypsinogen-activation peptide as markers for acute pancreatitis in cats

The purpose of this study was to compare the clinical utility of the serum concentration of feline trypsin-like immunoreactivity (fTLI), the plasma and urine concentrations of trypsinogen-activation peptide (TAP), and the ratio of the urine TAP and creatinine concentrations (TAP:Cr) in the diagnosis of feline acute pancreatitis. We used 13 healthy cats and 10 cats with a diagnosis of acute pancreatitis. The mean serum fTLI and plasma TAP concentrations were significantly higher in the cats with acute pancreatitis than in the healthy cats (P < 0.05); the mean urine TAP concentrations and the median urine TAP:Cr ratios were not significantly different. Among the cats examined in this study, there was no benefit of plasma TAP over serum fTLI in the evaluation of suspected acute pancreatitis.     

Liver glutathione concentrations in dogs and cats with naturally occurring liver disease

OBJECTIVE: To determine total glutathione (GSH) and glutathione disulfide (GSSG) concentrations in liver tissues from dogs and cats with spontaneous liver disease. SAMPLE POPULATION: Liver biopsy specimens from 63 dogs and 20 cats with liver disease and 12 healthy dogs and 15 healthy cats. PROCEDURE: GSH was measured by use of an enzymatic method; GSSG was measured after 2-vinylpyridine extraction of reduced GSH. Concentrations were expressed by use of wet liver weight and concentration of tissue protein and DNA. RESULTS: Disorders included necroinflammatory liver diseases (24 dogs, 10 cats), extrahepatic bile duct obstruction (8 dogs, 3 cats), vacuolar hepatopathy (16 dogs), hepatic lipidosis (4 cats), portosystemic vascular anomalies (15 dogs), and hepatic lymphosarcoma (3 cats). Significantly higher liver GSH and protein concentrations and a lower tissue DNA concentration and ratio of reduced GSH-to-GSSG were found in healthy cats, compared with healthy dogs. Of 63 dogs and 20 cats with liver disease, 22 and 14 had low liver concentrations of GSH (micromol) per gram of tissue; 10 and 10 had low liver concentrations of GSH (nmol) per milligram of tissue protein; and 26 and 18 had low liver concentrations of GSH (nmol) per microgram of tissue DNA, respectively. Low liver tissue concentrations of GSH were found in cats with necroinflammatory liver disease and hepatic lipidosis. Low liver concentrations of GSH per microgram of tissue DNA were found in dogs with necroinflammatory liver disease and cats with necroinflammatory liver disease, extrahepatic bile duct occlusion, and hepatic lipidosis. CONCLUSIONS AND CLINICAL RELEVANCE: Low GSH values are common in necroinflammatory liver disorders, extrahepatic bile duct occlusion, and feline hepatic lipidosis. Cats may have higher risk than dogs for low liver GSH concentrations.     

Serum total prostatic and non-prostatic acid phosphatase in healthy dogs and in dogs with prostatic diseases

Total acid phosphatase (TAP), prostatic acid phosphatase (PAP) and non-prostatic acid phosphatase (NPAP) serum concentrations were determined using a spectrophotometric technique in 52 healthy dogs, 15 male dogs suffering from non-prostatic diseases and in 19 dogs suffering from prostatic diseases (12 dogs with benign prostatic hypertrophy and seven dogs with prostatic adenocarcinoma). TAP, PAP and NPAP serum concentrations did not differ between normal male and normal female dogs. Dogs with prostatic adenocarcinoma had significantly higher TAP, PAP and NPAP serum concentrations than dogs with benign prostatic hypertrophy, normal dogs and dogs with non-prostatic disease. The authors conclude that low serum concentrations of TAP and PAP do not rule out prostatic adenocarcinoma in the dog, but elevated concentrations can be useful criteria for the diagnosis of canine prostatic cancer.     

Assessment of lipid peroxidation and serum vitamin E concentration in dogs with immune-mediated hemolytic anemia

OBJECTIVE: To determine plasma malondialdehyde (MDA) and serum vitamin E concentrations in dogs with immune-mediated hemolytic anemia (IMHA) and healthy control dogs. SAMPLE POPULATION: Serum and plasma samples from 36 dogs with IMHA and 40 healthy control dogs. PROCEDURE: Blood samples were collected from all study dogs. Plasma MDA concentrations were measured by use of a commercial colorimetric assay, and serum vitamin E concentrations (alpha-, gamma, and delta-tocopherol concentrations) were measured via high-performance liquid chromatography. RESULTS: Plasma MDA concentrations were significantly higher in the dogs with IMHA than in the control dogs. Compared with control dogs, serum alpha-, gamma-, and &tocopherol concentrations were significantly lower in the IMHA-affected dogs. CONCLUSIONS AND CLINICAL RELEVANCE: Results indicated a state of oxidative stress and reduced antioxidant reserve in dogs with IMHA; this finding provides support for further investigation of the potential benefits of antioxidant treatment in dogs with this disease.     

Plasma thyroid hormone concentrations in dogs competing in a long-distance sled dog race

Plasma thyroxine (T4), 3,5,3'-triiodothyronine (T3), total protein, and albumin concentrations were measured in 15 dogs both before and after completion, and in an additional 16 dogs before and 24 dogs after completion, of a long-distance sled dog race. The plasma T4 concentration (mean +/- SD) decreased significantly from 18.2 +/- 5.4 nmol/L before to 14.3 +/- 3.5 nmol/L after the race in dogs evaluated at both times and decreased significantly from 21.8 +/- 10.5 nmol/L before to 15.8 +/- 4.9 nmol/L after the race in dogs sampled only before or only after the race. The mean plasma T3 concentrations in dogs measured twice decreased significantly from 1.20 +/- 0.48 nmol/L before to 0.74 +/- 0.42 nmol/L after the race, as well as in dogs measured either before (1.28 +/- 0.36 nmol/L) or after (0.69 +/- 0.28 nmol/L) the race, respectively. Plasma total protein and albumin concentrations decreased significantly after completion of the race. No significant change was noted in 4 control dogs that did not compete in the race and were tested during a similar time period. The plasma concentrations of T4 and T3 were lower than the normal reference range established for this laboratory in 23 and 39%, respectively, of Alaskan sled dogs tested before the race. Plasma thyroid hormone concentrations frequently are below normal in conditioned Alaskan sled dogs and are further reduced after prolonged submaximal exercise.     

Additive effects of a sodium chloride restricted diet and furosemide administration in healthy dogs.

OBJECTIVE: To determine the effects of a low or high sodium (Na) diet with or without furosemide administration on plasma electrolyte concentrations and the renin-angiotensin-aldosterone system in healthy dogs. ANIMALS: 20 healthy adult dogs. PROCEDURE: Dogs were randomly allotted to 4 groups of 5 dogs each as follows: dogs fed a low Na diet (0.08% Na and 0.8% chloride [CI] on a dry matter [DM] basis); dogs fed a low Na diet with added NaCl (1.0% Na and 2.2% Cl on a DM basis); dogs fed a low Na diet and treated with furosemide (2 mg/kg of body weight, PO, q 12 h); and dogs fed a low Na diet with added NaCl and treated with furosemide. Plasma electrolyte concentrations were measured on days 0, 21, and 35. Plasma renin activity and aldosterone concentration were analyzed by use of radioimmunoassays on days 0, 21, 35, and 53. RESULTS: Furosemide treatment significantly decreased plasma Cl concentration and significantly increased plasma renin activity and aldosterone concentration. Dogs fed a low Na diet had significantly higher plasma renin activities and plasma aldosterone concentrations. A significant interaction between a low Na diet and furosemide administration resulted in the lowest plasma Cl concentrations, highest plasma renin activities, and highest plasma aldosterone concentrations. CONCLUSIONS AND CLINICAL RELEVANCE: In healthy dogs, feeding a low Na diet and administering furosemide resulted in an additive effect on plasma Cl concentration, renin activity, and aldosterone concentration, which may be an important consideration for treating dogs with cardiac disease.     

Serum amylase and isoamylases and their origins in healthy dogs and dogs with experimentally induced acute pancreatitis

Agarose-gel electrophoresis was used to study isoamylases in tissues and sera of healthy dogs and the sera of dogs with experimentally induced acute pancreatitis. Three or 4 isoamylases were found in the serum of healthy dogs; they were numbered 1 to 4 with respect to their degree of anodal migration. Peak 4 isoamylase, the slowest migrating (most cathodal), was the major isoamylase fraction in sera and tissues of healthy dogs. Peak 3 was identified as a pancreas-specific isoamylase. Absolute total serum amylase and total isoamylase concentrations increased significantly in dogs with pancreatitis compared with values for control dogs (sham-operated). The relative increase in peak 3 isoamylase was greater than that seen with total amylase or the other isoamylases. The decrease in total serum amylase and isoamylase concentrations paralleled each other; however, peak 3 remained proportionally high longer than did total amylase and the other isoamylase fractions. These findings indicate that measurement of peak 3 isoamylase concentrations may be of diagnostic value in dogs with suspected pancreatitis with normoamylasemia and in dogs with extrapancreatic hyperamylasemia.     

Vasopressin, cortisol, and catecholamine concentrations in dogs with dilated cardiomyopathy

OBJECTIVE: To evaluate plasma concentrations and urinary excretion of vasopressin and cortisol and urinary excretion of catecholamines in dogs with dilated cardiomyopathy (DCM). ANIMALS: 15 dogs with clinical signs of DCM, 15 dogs with preclinical DCM, and 15 control dogs. PROCEDURE: Physical examinations, thoracic radiography, ECG, and echocardiography were performed on all dogs. Blood and urine samples were collected. RESULTS: Plasma concentration of vasopressin and the urine cortisol-to-urine creatinine ratio were significantly increased in dogs with clinical signs of DCM and dogs with preclinical DCM, compared with control dogs. Plasma vasopressin concentration was significantly higher in dogs with clinical signs of DCM, compared with dogs with preclinical DCM. Urine vasopressin-to-urine creatinine ratio was significantly increased in dogs with clinical signs of DCM, compared with dogs with preclinical DCM and control dogs. Urine epinephrine-to-urine creatinine ratio and urine norepinephrine-to-urine creatinine ratio were significantly increased in dogs with clinical signs of DCM, compared with control dogs. Plasma concentration of cortisol and urine dopamine-to-urine creatinine ratio did not differ significantly among groups. CONCLUSIONS AND CLINICAL RELEVANCE: According to this study, the neuroendocrine pattern is changed in dogs with preclinical DCM. These changes are even more pronounced in dogs with clinical signs of DCM. Analysis of concentrations of vasopressin, cortisol, and catecholamines may aid in identification of the clinical stages of DCM. These findings may also provide a basis for additional studies of the possible beneficial effects of vasopressin antagonists and beta-adrenergic receptor antagonists in the treatment of dogs with congestive heart failure and DCM.     

Plasma adrenomedullin concentration in dogs with myxomatous mitral valvular disease

Adrenomedullin (AM), a peptide identified to have vasodilating and natriuretic effects, is involved in the regulation of the cardiovascular system. To evaluate plasma AM concentration in dogs with myxomatous mitral valvular disease (MMVD), and to investigate the associations between the concentrations of plasma AM and natriuretic peptides and the echocardiographic data, we evaluated plasma AM concentrations in 31 healthy control dogs and 57 dogs with MMVD. Plasma AM concentrations in dogs with MMVD were higher than that in the control subjects. The plasma AM concentration increased in conjunction with the severity of heart failure according to the International Small Animal Cardiac Health Council (ISACHC). The AM concentrations were 25.1 ± 5.0 fmol/ml (ISACHC class Ia), 29.9 ± 11.0 fmol/ml (ISACHC class Ib), 43.4 ± 19.8 fmol/ml (ISACHC class II) and 73.5 ± 21.7 fmol/ml (ISACHC class III) and 7.5 ± 5.1 fmol/ml (control group), respectively. The receiver operating characteristic curve indicated an area of 0.93 (95% CI, 0.8801-0.9889; <0.0001), a cutoff value of 30.5 fmol/ml, a sensitivity of 87.1%, and a specificity of 82.5% for the determination of congestive heart failure. Plasma AM concentrations correlated with atrial natriuretic peptide concentrations, LA/Ao ratio, and left ventricular diameter. In conclusion, AM may be a potential diagnostic marker for canine MMVD and possibly plays a pathophysiological role in collaboration with the other neurohumoral factors such as natriuretic peptides.     

Diagnostic and prognostic value of endothelin-1 plasma concentrations in dogs with heart and respiratory disorders

The endothelin-1 (ET-1) plasma concentration was measured in dogs with spontaneous cardiac or respiratory diseases. Plasma samples were obtained from 76 healthy control dogs and 73 dogs, of which 58 were suffering from heart disease and 15 were suffering from respiratory disease. Dogs were evaluated using echocardiography, thoracic radiography, biochemical evaluation and a radioimmunoassay for ET-1. ET-1 plasma concentrations were significantly higher in dogs with spontaneous cardiac or respiratory diseases (mean [se] 5.3 [0.3] and 5.3 [0.6] pg/ml, respectively) than in healthy dogs (1.9 [0.1] pg/ml) (P<0.0001). ET-1 plasma concentrations increased with the class of heart failure (International Small Animal Cardiac Health Council classification) (P<0.0001) and with the severity of pulmonary disorders. ET-1 plasma concentrations were positively correlated with the extent of systolic pulmonary hypertension measured by Doppler echocardiography (P<0.05; r=0.75) and with the clinical outcome of dogs with respiratory disease. Evaluation of the ET-1 plasma concentration allowed differentiation between heart and respiratory disorders in dogs exhibiting clinical signs at exercise, but not in patients exhibiting clinical signs at rest.     

Assessing the severity of canine pancreatitis

The objective of this study was to determine whether laboratory testing currently available is able to provide prognostic information in canine pancreatitis. A prospective study of dogs with naturally occurring pancreatitis was undertaken. Twenty-two cases with histologically confirmed pancreatic inflammation were included in the study. Each dog had routine haematology parameters, serum biochemistry (including lipase and amylase), serum trypsin-like immunoreactivity and trypsinogen activation peptides (TAP) in urine and plasma measured. Twelve of the dogs were classified as having severe disease. These dogs had statistically significant increases in urinary TAP-creatinine ratio (UTCR) measurement, serum lipase, serum phosphate and serum creatinine concentrations. Additionally dogs with severe pancreatitis had significantly decreased urine specific gravity levels. The most sensitive and specific test to assess the severity of pancreatitis was the measurement of UTCR.     

Measurement of plasma atrial natriuretic peptide as an indicator of prognosis in dogs with cardiac disease

Twenty-three dogs with heart failure were evaluated in a 12-month study by measuring baseline plasma atrial natriuretic peptide (ANP) concentrations. Ten dogs were classified as having mild to moderate cardiac disease (group 1) and 13 dogs were classified as having severe cardiac disease (group 2). The mean plasma ANP concentration for the group 1 dogs was 64 +/- 45 pg/mL and for the group 2 dogs, 328 +/- 122 pg/mL. The median survival time (1,095 d) for group 1 dogs was significantly greater (P < 0.05) than for group 2 dogs (58 d). A significantly (P < 0.05) greater median survival was noted for dogs with plasma ANP < 95 pg/mL (1095 d) compared with those with ANP > 95 pg/mL (58 d). Plasma ANP concentrations are a potential noninvasive predictor of survival in dogs with heart failure.