Relationship between dietary protein concentration and serum trypsin-like immunoreactivity in dogs

Serum trypsinogen concentration was studied in 6 adult mixed-breed dogs randomly fed diets containing 6.8, 31.4, or 39.7% protein (dry weight) for 3 weeks each. Blood was collected on days 20, 21, and 22 of each feeding period, and serum trypsinogen concentrations were determined by radioimmunoassay of trypsin-like immunoreactivity (TLI). Mean serum TLI concentrations for each dog fed each diet were compared. A significant (P less than 0.05) positive linear relationship (P less than 0.02) was determined between serum TLI concentrations and the percentage of dietary protein. Mean serum TLI concentrations for each dog fed all diets ranged from 5.7 to 20.2 micrograms/L.     

Serum feline trypsin-like immunoreactivity following administration of ceruletide to healthy cats

OBJECTIVE: To determine changes in serum feline trypsin-like immunoreactivity (fTLI) in response to administration of ceruletide to healthy cats. ANIMALS: 11 healthy cats. PROCEDURES: Serum fTLI was determined, using a radioimmunoassay, before and 10, 20, 30, 40, and 50 minutes after IM administration of ceruletide (0.3 mg/kg [0.14 mg/lb]). RESULTS: Mean +/- SD baseline serum fTLI was 23.1 +/- 4.1 mg/L. There was a statistically significant, but clinically unimportant, increase in serum fTLI 10 and 30 minutes after ceruletide administration. CONCLUSIONS AND CLINICAL RELEVANCE: In healthy cats, administration of ceruletide induced a statistically significant, but clinically unimportant, increase in serum fTLI. Whether responses in cats with exocrine pancreatic disorders would be different is unknown, but results suggest that a ceruletide stimulation test would likely not be useful for differentiating between healthy cats and cats with subclinical chronic exocrine pancreatic disorders.     

Influence of feeding on serum feline trypsin-like immunoreactivity.

OBJECTIVE: To determine whether feeding causes a change in feline trypsin-like immunoreactivity (fTLI) in serum from healthy cats. ANIMALS: 6 healthy domestic shorthair cats. PROCEDURES: For the first 12 days of the study, 3 cats were fed a high-protein, high-fat (diet 1), and the other 3 were fed a maintenance (diet 2). On day 12, diets were switched, and cats were fed the other diet for the remaining 12 days of the study. On days 11 and 23, food was withheld for 24 hours, and baseline serum fTLI was measured. Cats were offered food equivalent to half their daily caloric maintenance requirements, and serum fTLI was measured 1, 2, 4, 6, 12, and 24 hours later. Uneaten food was removed after 1 hour. RESULTS: Overall mean +/- SD serum fTLI was 22.7 +/- 5.8 micrograms/L when cats were fed diet 1 and 21.1 +/- 5.0 micrograms/L when cats were fed diet 2. There was no significant difference in serum fTLI over time or between diets. However, there was a statistically significant, but clinically unimportant (mean increase, 1.7 micrograms/L), increase in serum fTLI, compared with baseline values, 1 hour after cats were fed diet 2 but not when cats were fed diet 1. CONCLUSIONS AND CLINICAL RELEVANCE: A maintenance diet may cause a clinically unimportant increase in serum fTLI 1 hour after feeding in healthy cats. Results suggest that for healthy cats, it is not necessary to withhold food before collecting samples for determination of fTLI in serum. Whether feeding changes fTLI in serum from cats with disorders of the exocrine portion of the pancreas remains to be determined.     

One-step immunochromatography assay for detection of high-level canine serum trypsin-like immunoreactivity

We developed a one-step immunochromatography assay kit to measure high levels of canine trypsin-like immunoreactivity (cTLI) for bedside estimation of canine pancreatitis. The serum cTLI level can be determined within 10 min by visual comparison of color strengths in the test and reference zones. The serum cTLI levels determined by this method correlate well with canine TLI-ELISA and can be classified into 3 categories: cTLI levels higher than 60 ng/ml were considered positive; 20-60 ng/ml, weakly positive; and less than 20 ng/ml, negative. Twelve dogs suspected of pancreatitis were examined using this method; 4 dogs were positive, 2 were weakly positive, and 6 were negative. This test can detect a high level of serum cTLI and a positive result in the TLIH test will provide critical information for evaluation of pancreatitis in dogs.     

Evaluation of serum feline trypsin-like immunoreactivity for the diagnosis of pancreatitis in cats

OBJECTIVE: To evaluate serum feline trypsin-like immunoreactivity (fTLI) concentration and results of abdominal ultrasonography, CBC, and serum biochemical analyses for diagnosis of pancreatitis in cats. DESIGN: Prospective study. ANIMALS: 28 cats with clinical signs compatible with pancreatitis. PROCEDURE: Serum fTLI concentrations were determined, and abdominal ultrasonography, CBC, and serum biochemical analyses were performed prior to histologic evaluation of pancreatic, hepatic, and intestinal specimens. On the basis of histologic results, cats were categorized as having a normal pancreas (n = 10), pancreatic fibrosis with ongoing inflammation (9), pancreatic fibrosis without inflammation (4), and acute necrotizing pancreatitis (5). Serum fTLI concentrations and results of CBC, serum biochemical analyses, and histologic evaluation of hepatic and intestinal specimens were compared among groups. RESULTS: Significant differences in serum fTLI concentrations or any hematologic or biochemical variable were not detected among the 4 groups of cats. Median serum fTLI concentrations were 51 micrograms/L (range, 18 to 200 micrograms/L) in cats with a normal pancreas, 32 micrograms/L (range, 12 to > 200 micrograms/L) in cats with pancreatic fibrosis and ongoing inflammation, 124 micrograms/L (range, 36 to > 200 micrograms/L) in cats with pancreatic fibrosis without ongoing inflammation, and 30 micrograms/L (range, 24 to 84 micrograms/L) in cats with acute necrotizing pancreatitis. We detected a high prevalence of concurrent hepatic and intestinal tract disease in cats with pancreatitis. CONCLUSIONS AND CLINICAL RELEVANCE: In cats with clinical signs of pancreatitis, serum fTLI concentration is poorly associated with histopathologic diagnosis.     

Effects of oral administration of furosemide and torsemide in healthy dogs

OBJECTIVE: To investigate the diuretic effects, tolerability, and adverse effects of furosemide and torsemide after short- and long-term administration in healthy dogs. ANIMALS: 8 mixed-breed dogs. PROCEDURES: In a crossover study, furosemide (2 mg/kg), torsemide (0.2 mg/kg), or placebo (bifidobacterium [1 mg/kg]) was administered orally to each dog every 12 hours for 14 days. Blood and urine samples were collected before the study (baseline data) and at intervals on the 1st (short-term administration) and 14th day (long-term administration) of treatment for assessment of urine volume and specific gravity and selected clinicopathologic variables including BUN, creatinine, and aldosterone concentrations, and creatinine clearance. RESULTS: Compared with the baseline value, short-term administration of furosemide or torsemide immediately increased urine volume significantly; after long-term administration of either drug, urine specific gravity decreased significantly. Compared with the effect of placebo, the 24-hour urine volume was significantly increased after short-term administra-tion of furosemide or torsemide. In addition, it was significantly increased after long-term administration of torsemide, compared with that of short-term administration. Long-term administration of furosemide or torsemide increased the BUN and plasma creatinine con-centrations, compared with the baseline value. Compared with the baseline value, plasma aldosterone concentration was significantly increased after long-term administration of either drug and was significantly higher after torsemide treatment than after furosemide treatment. CONCLUSIONS AND CLINICAL RELEVANCE: In dogs, diuretic resistance developed after 14 days of furosemide, but not torsemide, administration; however, both loop diuretics were associated with increased BUN and plasma creatinine concentrations, compared with values before treatment.     

Effects of dexamethasone on pancreatic tissue and on serum amylase and lipase activities in dogs

The effects of dexamethasone on the pancreas and on pancreatic amylase and lipase activities were determined in clinically normal dogs and in dogs with neurologic disease. Dexamethasone increased serum lipase activity without any histologic damage to the pancreas in either group of dogs. It decreased serum amylase activity in the normal dogs and had a variable effect in dogs with neurologic disease, with or without confirmed pancreatitis. It was suggested that high serum lipase activity in dexamethasone-treated dogs may not be attributable to pancreatitis and that the reasons are still unknown. It was concluded that high serum lipase activity is an unreliable basis for diagnosis of pancreatitis in dogs treated with dexamethasone. The data allowed no conclusion about an additive effect of dexamethasone and neurologic disease causing pancreatitis.     

Effects of long-term oral administration of ketoprofen in clinically healthy beagle dogs

To investigate the adverse effects of long-term administration of ketoprofen in dogs, ketoprofen (1 mg/kg) was administered to five clinically healthy beagle dogs (ketoprofen group) and gelatin capsules (control group) were administered to four clinically healthy beagle dogs for 30 days. We monitored the dogs through periodic physical examination, blood analyses, endoscopic examinations, fecal occult blood tests, renal function tests, urinalysis, urinary enzyme indices and cuticle bleeding time analysis. The lesions in the stomach, especially in the pyloric antrum, and fecal occult blood progressively worsened in the ketoprofen group. However, the differences between the ketoprofen group and the control group were not statistically significant. One dog in the ketoprofen group temporarily exhibited a decrease in renal plasma flow and two dogs exhibited enzymuria. However, these changes did not persist and the other examinations showed no significant difference between premedication and postmedication in the ketoprofen group. Therefore, the adverse effects of long-term administration of ketoprofen observed in this study were not clinically important in healthy dogs. Nevertheless, further investigation of adverse renal effects from long-term administration of ketoprofen is necessary in the dogs with subclinical renal disease.     

Diagnosis of canine exocrine pancreatic insufficiency by the assay of serum trypsin-like immunoreactivity

A radioimmunoassay for canine serum trypsin-like immunoreactivity (TLI) has been developed and evaluated for use in the diagnosis of exocrine pancreatic insufficiency (EPI). The maximum fasting TLI concentration in 14 dogs with EPI was 1.8 μg/l, compared with a minimum value of 7.0 μg/l in a control group of 75 dogs. The measurement of serum TLI therefore provides a sensitive test for the diagnosis of EPI in the dog.     

Effect of pancreatectomy on plasma activities of amylase, isoamylase, lipase and trypsin-like immunoreactivity in dogs.

The contribution of the pancreas to the plasma activities of amylase, isoamylase, lipase and the concentration of trypsin-like immunoreactivity (TLI) in the dog was examined by measuring the activities of these enzymes before and after total pancreatectomy. Pancreatectomy was followed by a decrease in the concentration of TLI (from 6.2 +/- 0.3 micrograms litre-1 to 1.2 +/- 0.3 micrograms litre-1; P less than 0.001) and activity of isoamylase peak 4 (from 1257 +/- 105 iu litre-1 to 894 +/- 171 iu litre-1; P less than 0.05). Though significantly reduced, the activities of peak 4 isoamylase were still within the normal range for control dogs. Pancreatectomy did not significantly alter the activities of amylase, lipase or isoamylase peaks 1, 2 and 3. These findings provide strong evidence that the pancreas is not the sole source of circulating amylase, isoamylase and lipase activities. In contrast the marked reductions in TLI to values close to the limits of assay sensitivity suggest that TLI is derived from the pancreas alone. The results indicate that assay of circulating TLI provides a more sensitive and specific indicator of pancreatic exocrine mass than plasma amylase, lipase or isoamylase activities.     

High serum trypsin-like immunoreactivity secondary to pancreatitis in a dog with exocrine pancreatic insufficiency

A 13-year-old spayed Doberman Pinscher with acute vomiting of 24 hours' duration and concurrent 2-week history of polyphagia with weight loss had diabetic ketoacidosis complicated by acute pancreatitis and exocrine pancreatic insufficiency. Diagnostic testing for exocrine pancreatic insufficiency, by determining serum trypsin-like immunoreactivity, revealed an unexpectedly high result when a low result was anticipated. High trypsin-like immunoreactivity was attributed to acute pancreatic inflammation.     

Circulating concentrations of trypsin-like immunoreactivity and activities of lipase and amylase after pancreatic duct ligation in dogs

The possibility that assay of circulating trypsin-like immunoreactivity (TLI) could assist in the diagnosis of acute pancreatitis in dogs has been examined by assaying plasma TLI concentrations after pancreatic duct ligation and comparing the results with plasma activities of lipase and amylase. Venous blood samples were obtained from 8 dogs before surgery, then daily for 5 days and at 14 days after ligation of pancreatic ducts. Plasma concentrations of TLI increased within 24 hours and tended to peak before and to decrease more rapidly than activities of lipase and amylase, remaining greater than the control range for 5 days in all but 2 dogs. Plasma lipase and amylase activities increased together and remained greater than the control range in all dogs for 5 days after surgery. Regression analysis of all postoperative data indicated significant correlations between concentration of TLI and lipase activity (r = 0.67, P less than 0.001), concentration of TLI and amylase activity (r = 0.53, P less than 0.001), and between lipase and amylase activities (r = 0.74, P less than 0.001). These findings suggested that assay of TLI may provide an early indication of acute pancreatitis in dogs. Because TLI is specifically pancreatic in origin, high plasma TLI concentration may prove a more reliable indicator of clinical pancreatitis than high activities of amylase or lipase, which may be derived from extrapancreatic tissues.     

Endoscopic evaluation of the gastroduodenal mucosa to determine the safety of short-term concurrent administration of meloxicam and dexamethasone in healthy dogs

OBJECTIVE: To evaluate the safety, with respect to the development of gastric ulcers and erosions, of concurrent administration of meloxicam and dexamethasone for 3 days to healthy dogs. ANIMALS: 20 conditioned purpose-bred research Beagles. PROCEDURE: Seven days prior to treatment, dogs were anesthetized for endoscopic evaluation of the upper portion of the gastrointestinal tract (ie, the gastric and duodenal mucosa). Five regions of the gastroduodenal area were scored by 2 investigators. Dogs were randomly assigned to 1 of 4 treatment groups as follows: saline-saline, dexamethasone-saline, saline-meloxicam, and dexamethasone-meloxicam groups. On days 1, 2, and 3, dogs received either dexamethasone or saline (0.9% NaCl) solution injections SC twice daily. On days 2, 3, and 4, dogs received either meloxicam or saline solution injections SC once daily. On day 2, dogs were anesthetized for a sham surgery (ie, electrostimulation). On day 5, the gastroduodenal area of each dog was reevaluated by use of endoscopic evaluation and histologic examination of biopsy specimens. RESULTS: The total endoscopic score of the dexamethasone-meloxicam group was significantly greater than the scores of the other groups. The dexamethasone-saline group had a mean cumulative score that was significantly greater than the saline-meloxicam or saline-saline groups. Endoscopic scores of the saline-meloxicam group were not significantly different from scores of the saline-saline group. No significant differences in histologic findings were found between groups. CONCLUSIONS AND CLINICAL RELEVANCE: In healthy dogs, meloxicam appears to be safe with regard to adverse effects on the gastrointestinal tract. Concurrent administration of dexamethasone and meloxicam is more likely to cause gastric erosions than meloxicam administration alone.     

Effects of single intravenous doses of dexamethasone on baseline plasma cortisol concentrations and responses to synthetic ACTH in healthy dogs

The duration of adrenocortical suppression resulting from a single IV dose of dexamethasone or dexamethasone sodium phosphate was determined in dogs. At 0800 hours, 5 groups of dogs (n = 4/group) were treated with 0.01 or 0.1 mg of either agent/kg of body weight or saline solution (controls). Plasma cortisol concentrations were significantly (P less than 0.01) depressed in dogs given either dose of dexamethasone or dexamethasone sodium phosphate by posttreatment hour (PTH) 2 and concentrations remained suppressed for at least 16 hours. However, by PTH 24, plasma cortisol concentrations in all dogs, except those given 0.1 mg of dexamethasone/kg, returned to control values. Adrenocortical suppression was evident in dogs given 0.1 mg of dexamethasone/kg for up to 32 hours. The effect of dexamethasone pretreatment on the adrenocortical response to ACTH was studied in the same dogs 2 weeks later. Two groups of dogs (n = 10/group) were tested with 1 microgram of synthetic ACTH/kg given at 1000 hours or 1400 hours. One week later, half of the dogs in each group were given 0.01 mg of dexamethasone/kg at 0600 hours, whereas the remaining dogs were given 0.1 mg of dexamethasone/kg. The ACTH response test was then repeated so that the interval between dexamethasone treatment and ACTH injection was 4 hours (ACTH given at 1000 hours) or 8 hours (ACTH given at 1400 hours). Base-line plasma cortisol concentrations were reduced in all dogs given dexamethasone 4 or 8 hours previously.(ABSTRACT TRUNCATED AT 250 WORDS)     

Effects of pre‐operative administration of medetomidine on plasma insulin and glucose concentrations in healthy dogs and dogs with insulinoma

ObjectiveTo investigate the effect of medetomidine on plasma glucose and insulin concentrations in dogs with insulinoma and in healthy dogs undergoing anesthesia and surgery.AnimalsTwenty–five dogs with insulinoma and 26 healthy dogs.MethodsIn dogs with insulinoma, medetomidine (5 μg kg^?1) was randomly included (n = 12) or omitted (n = 13) from the pre–anesthetic medication protocol, which typically contained an opioid and an anticholinergic. Healthy dogs received medetomidine (5 μg kg^?1; n = 13) or acepromazine (0.04 mg kg^?1; n = 13) plus an opioid (morphine 0.5 mg kg^?1) and an anticholinergic (atropine 0.04 mg kg^?1) as pre–anesthetic medications. Pre–anesthetic medications were given intramuscularly. Plasma glucose and insulin concentrations were measured before (sample 1) and 30 minutes after pre–anesthetic medication (sample 2), and at the end of surgery in dogs with insulinoma or at 2 hours of anesthesia in healthy dogs (sample 3). Glucose requirement to maintain intra–operative normoglycemia in dogs with insulinoma was quantified and compared. Data were analyzed with anova and Bonferroni post–test, t–tests or chi–square tests as appropriate with p < 0.05 considered significant. Data are shown as mean ± SD.ResultsMedetomidine significantly decreased plasma insulin concentrations and increased plasma glucose concentrations in healthy dogs and those with insulinoma. These variables did not change significantly in the dogs not receiving medetomidine. In the dogs with insulinoma, intra–operative glucose administration rate was significantly less in the animals that received medetomidine compared to those that did not.ConclusionsPre–anesthetic administration of medetomidine significantly suppressed insulin secretion and increased plasma glucose concentration in dogs with insulinoma and in healthy dogs undergoing anesthesia and surgery.Clinical relevanceThese findings support the judicious use of medetomidine at low doses as an adjunct to the anesthetic management of dogs with insulinoma.