Administration of charcoal, Yucca schidigera, and zinc acetate to reduce malodorous flatulence in dogs

OBJECTIVE: To determine whether feeding activated charcoal, Yucca schidigera, and zinc acetate would ameliorate the frequency and odor characteristics of flatulence in dogs. DESIGN: In vitro screening of active agents followed by a randomized controlled trial. ANIMALS: 8 adult dogs. PROCEDURE: A fecal fermentation system was used to assess the effects of activated charcoal, Yucca schidigera, and zinc acetate alone and in combination on total gas production and production of hydrogen sulfide, the primary determinant of flatus malodor in dogs. All 3 agents were subsequently incorporated into edible treats that were fed 30 minutes after the dogs ate their daily rations, and the number, frequency, and odor characteristics of flatulence were measured for 5 hours, using a device that sampled rectal gases and monitored hydrogen sulfide concentrations. RESULT: Total gas production and number and frequency of flatulence episodes were unaffected by any of the agents. Production of hydrogen sulfide in vitro was significantly reduced by charcoal, Yucca schidigera, and zinc acetate by 71, 38, and 58%, respectively, and was reduced by 86% by the combination of the 3 agents. Consumption of the 3 agents was associated with a significant decrease (86%) in the percentage of flatulence episodes with bad or unbearable odor and a proportional increase in the percentage of episodes of no or only slightly noticeable odor. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that activated charcoal, Yucca schidigera, and zinc acetate reduce malodor of flatus in dogs by altering the production or availability of hydrogen sulfide in the large intestine.     

In vivo measurement of flatulence and nutrient digestibility in dogs fed poultry by-product meal, conventional soybean meal, and low-oligosaccharide low-phytate soybean meal

OBJECTIVE: To determine an optimal window for determining peak flatulence and evaluate the effects of oligosaccharides and supplemental beta-mannanase in soybean meal-based diets on nutrient availability and flatulence. ANIMALS: 6 dogs. PROCEDURES: Dogs were used in a 2 x 3 factorial arrangement of treatments in a 6 x 6 Latin square experiment to evaluate the digestibility, flatulence, and fecal odor metabolites of low-oligosaccharide low-phytate soybean meal (LLM), conventional soybean meal (SBM), and poultry by-product (PBP) meal diets with or without supplemental beta-mannanase (5 g/kg). RESULTS: Enzyme supplementation had no effect on total tract dry matter (DM), nitrogen digestibility, or digestible energy; however, differences between protein sources did exist for total tract DM digestibility and digestible energy. The PBP meal had higher DM digestibility and digestible energy (mean, 0.913 and 4,255 cal/g), compared with soy-based diets (mean, 0.870 and 4,049 cal/g). No differences were detected for any treatment regardless of protein source or addition of supplemental enzyme for any flatulence components analyzed. No differences were detected for all fecal odor metabolites regardless of addition of supplemental enzyme; however, differences between protein sources were detected. The PBP meal had lower concentrations of carboxylic acids and esters and higher concentrations of heterocycles, phenols, thio and sulfides, ketones, alcohols, and indoles than LLM and SBM. CONCLUSIONS AND CLINICAL RELEVANCE: Diets containing < 22.4 g of stachyose/kg and < 2 g of raffinose/kg did not alter digestibility or increase flatulence in dogs.     

Serum salicylate concentrations and endoscopic evaluation of the gastric mucosa in dogs after oral administration of aspirin-containing products

The serum salicylate concentration produced by oral administration of plain aspirin and several aspirin-containing products given at 8-hour intervals for 7 treatments was measured in 36 laboratory-conditioned adult dogs. The dogs were randomly allotted to 6 groups of 6 dogs each: group 1 was given plain aspirin at a dosage of 25 mg/kg of body weight: group 2 was given plain aspirin at a dosage of 10 mg/kg; group 3 was given buffered aspirin at a dosage of 25 mg/kg; group 4 was given enteric-coated aspirin at a dosage of 25 mg/kg; group 5 was given buffered aspirin at a dosage of 25 mg/kg; and, group 6 was given a placebo. Serum salicylate concentration was measured at 2-hour intervals for the first 8 hours, and then at 8-hour intervals for the next 40 hours. Following the last dosing, serum salicylate concentration was measured at 2-hour intervals until 56 hours; the final 2 samples were measured at 64 and 72 hours. The effect of aspirin on the gastric mucosa was studied in 12 dogs, 3 each randomly selected from groups 1, 3, 4, and 5. The gastric mucosa of each dog was examined with a fiberoptic gastroscope 3 days before the beginning of treatment; lesions were not seen. The drugs were administered as described and the gastric mucosa of each dog was reexamined at 72 hours. Administration of the aspirin-containing products at 8-hour intervals resulted in sustained therapeutic serum salicylate concentrations (greater than 5 mg/dl) in all dogs, except those of group 2. The greatest fluctuation in serum salicylate concentration was found in dogs of group 4. Gastric lesions were seen only in the 3 dogs of group 1.(ABSTRACT TRUNCATED AT 250 WORDS)     

Assessment of plasma brain natriuretic peptide concentration in Boxers with arrhythmogenic right ventricular cardiomyopathy

OBJECTIVE: To determine whether Boxers with a clinical diagnosis of arrhythmogenic right ventricular cardiomyopathy (ARVC) have increased plasma concentrations of brain natriuretic peptide (BNP), compared with concentrations in clinically normal dogs. ANIMALS: 13 Boxers with ARVC, 9 clinically normal Boxers, 10 clinically normal non-Boxer dogs, and 5 hound dogs with systolic dysfunction. PROCEDURE: All Boxers were evaluated via 24-hour ambulatory electrocardiography and echocardiography; the number of ventricular premature contractions (VPCs) per 24 hours was assessed. Hound dogs with cardiac pacing-induced systolic dysfunction (positive control dogs) and clinically normal non-Boxer dogs (negative control dogs) were evaluated echocardiographically. Three milliliters of blood was collected from each dog for measurement of plasma BNP concentration by use of a radioimmunoassay. RESULTS: Mean +/- SD plasma BNP concentration for the ARVC-affected Boxers, clinically normal Boxers, negative control dogs, and positive control dogs was 11.0 +/- 4.6 pg/mL, 7.9 +/- 3.2 pg/mL, 11.5 +/- 4.9 pg/mL, and 100.8 +/- 56.8 pg/mL, respectively. Compared with findings in the positive control group, plasma BNP concentration in each of the other 3 groups was significantly different. There was no significant difference in BNP concentration between the 2 groups of Boxers. A significant correlation between plasma BNP concentration and number of VPCs per 24 hours in the ARVC-affected Boxers was not identified. CONCLUSIONS AND CLINICAL RELEVANCE: A significant difference in BNP concentration between Boxers with ARVC and clinically normal Boxers was not identified. Results suggest that BNP concentration may not be an indicator of ARVC in Boxers.     

Effects of diet on clinical signs of exocrine pancreatic insufficiency in dogs

OBJECTIVE: To assess the effects of dietary modification on clinical signs of exocrine pancreatic insufficiency (EPI) in dogs. DESIGN: Blinded randomized crossover study. ANIMALS: 21 dogs with EPI. PROCEDURE: Dogs were fed the diet they received at home for 2 weeks. Thereafter, they received 3 special diets (a high-fat diet, a high-fiber diet, and a highly digestible low-residue diet) for 3 weeks each. Owners scored dogs daily for the last 2 weeks of each 3-week period for severity of 6 clinical signs including appetite, defecation frequency, consistency of feces, borborygmus, flatulence, and coprophagia. An EPI index was calculated for each dog by adding the daily scores for each clinical sign. RESULTS: Significant differences in daily EPI indices among diets were observed in 20 dogs. The original diet appeared to be the most suitable in 8 dogs, whereas the high-fat diet was most suitable in 5 dogs, the high-fiber diet was most suitable in 4 dogs, and the low-residue diet was most suitable in 2 dogs. In 1 dog, the lowest EPI index score was the same during the original diet and the high-fat diet feeding periods. One dog did not complete the feeding period for the high-fiber diet. Differences in mean EPI indices among diets were not significant. CONCLUSIONS AND CLINICAL RELEVANCE: Results indicated that responses to different diets varied among individual dogs. Because responses to the feeding regimens were unpredictable, it is suggested that feeding regimens be individually formulated for dogs with EPI.     

Assessment of alterations in triglyceride and glycogen concentrations in muscle tissue of Alaskan sled dogs during repetitive prolonged exercise

OBJECTIVE: To assess changes in muscle glycogen (MG) and triglyceride (MT) concentrations in aerobically conditioned sled dogs during prolonged exercise. ANIMALS: 54 Alaskan sled dogs fed a high-fat diet. PROCEDURES: 48 dogs ran 140-km distances on 4 consecutive days (cumulative distance, up to 560 km); 6 dogs remained as nonexercising control animals. Muscle biopsies were performed immediately after running 140, 420, or 560 km (6 dogs each) and subsequently after feeding and 7 hours of rest. Single muscle biopsies were performed during recovery at 28 hours in 7 dogs that completed 560 km and at 50 and 98 hours in 7 and 6 dogs that completed 510 km, respectively. Tissue samples were analyzed for MG and MT concentrations. RESULTS: In control dogs, mean +/- SD MG and MT concentrations were 375 +/- 37 mmol/kg of dry weight (kgDW) and 25.9 +/- 10.3 mmol/kgDW, respectively. Compared with control values, MG concentration was lower after dogs completed 140 and 420 km (137 +/- 36 mmol/kgDW and 203 +/- 30 mmol/kgDW, respectively); MT concentration was lower after dogs completed 140, 420, and 560 km (7.4 +/- 5.4 mmol/kgDW; 9.6 +/- 6.9 mmol/kgDW, and 6.3 +/- 4.9 mmol/kgDW, respectively). Depletion rates during the first run exceeded rates during the final run. Replenishment rates during recovery periods were not different, regardless of distance; only MG concentration at 50 hours was significantly greater than the control value. CONCLUSIONS AND CLINICAL RELEVANCE: Concentration of MG progressively increased in sled dogs undergoing prolonged exercise as a result of attenuated depletion.     

Late-phase reactions to intradermal testing with Dermatophagoides farinae in healthy dogs and dogs with house dust mite-induced atopic dermatitis

OBJECTIVE: To determine the prevalence of late-phase reactions to intradermal testing with Dermatophagoides farinae in healthy dogs and dogs with atopic dermatitis and an immediate reaction to D farinae. ANIMALS: 6 healthy dogs and 20 dogs with atopic dermatitis and immediate reactions to D farinae. PROCEDURE: ntradermal tests were performed with D farinae at 1:1,000 wt/vol and 1:50,000 wt/vol concentrations, and skin reactivity was evaluated after 0.25, 6, and 24 hours. Serum D farinae-specific IgE antibodies were assayed. Extent of lesions (atopy index) and pruritus (visual analogue scale) were evaluated in dogs with atopic dermatitis. RESULTS: Late-phase reactions were observed in healthy dogs at 6 hours (n = 2 dogs) and 24 hours (1) with the 1:1,000 wt/vol concentration, and at 6 hours (1) and 24 hours (1) with the 1:50,000 wt/vol concentration of allergen. Late-phase reactions in healthy dogs were only observed in dogs with an immediate reaction to D farinae. Late-phase reactions were observed in 11 of 20 dogs with atopic dermatitis at 6 and 24 hours with the 1:1,000 wt/vol concentration and in 10 of 20 at 6 and 24 hours with the 1:50,000 wt/vol concentration of allergen. There was no difference in mean atopy index, mean visual analogue scale of pruritus, or mean serum D farinae-specific IgE concentration of dogs with a late-phase reaction, compared to dogs without a late-phase reaction. CONCLUSIONS AND CLINICAL RELEVANCE: Late-phase reactions may be observed after an immediate reaction to intradermal skin testing in healthy and allergic dogs but are more commonly observed in dogs with atopic dermatitis.     

Investigation of the effect of acepromazine on intravenous glucose tolerance tests in dogs

OBJECTIVE: To investigate the effects of administration of acepromazine on IV glucose tolerance tests (IVGTTs) in dogs. ANIMALS: 8 male mixed-breed dogs. PROCEDURE: With a 1-week interval between tests, each dog underwent (in random order) an IVGTT with or without pretest administration of acepromazine maleate (0.1 mg/kg, SC, 30 minutes prior to the start of the IVGTT). Food was withheld from the dogs for 14 hours prior to each test. Blood samples were obtained at 20, 10, and 1 minute prior to and at 2, 3, 4, 5, 6, 8, 10, 12, 14, 16, 19, 22, 25, 30, 40, 50, 60, 70, 80, 90, 100, 120, 140, 160, and 180 minutes after administration of glucose. RESULTS: There were no significant differences in the baseline (ie, after food was withheld) plasma glucose, lactate, and insulin concentrations between dogs undergoing the IVGTT and acepromazine-IVGTT; however, lower baseline free fatty acid concentration was observed in acepromazine-treated dogs. Analysis of data via the application of Bergman's minimal model of glucose kinetics revealed no differences in insulin sensitivity, acute insulin response to glucose, disposition index, or glucose effectiveness between dogs treated or not treated with acepromazine before testing. CONCLUSIONS AND CLINICAL RELEVANCE: Results indicated that in dogs undergoing IV glucose tolerance testing, pretest administration of small doses of acepromazine can be used as a means of chemical restraint without interfering with results of the glucose metabolism assessment.     

Flatulence in pet dogs

AIM: The purpose of this study was to obtain information on aspects of dogs' lifestyle and diet that may be related to flatulence, whether the dogs were flatulent or not and if the owners were concerned about flatulence of their pet. METHODS: The owners of 110 pet dogs were randomly selected from the Massey University clinic tiles and asked to complete a questionnaire relating to their dog's flatulence, lifestyle and diet. RESULTS: Flatulence was detected by 47 owners and occurred more often in less active inside dogs than those exercised more often. No individual food or dietary association was identified. Nineteen of the 47 owners of flatulent dogs would alter their dog's diet if that change would reduce flatulence. CONCLUSION: Flatulence occurs in pet dogs and most owners accept flatulence and were unconcerned about its consequence.     

Pituitary ACTH and adrenocortical secretion in critically ill dogs

OBJECTIVE: To evaluate pituitary-adrenal function in a population of critically ill dogs by measuring serial plasma concentrations of basal cortisol, ACTH-stimulated cortisol, and endogenous ACTH. DESIGN: Prospective study. ANIMALS: 20 critically ill dogs admitted to an intensive care unit (ICU). PROCEDURE: Basal plasma cortisol, ACTH-stimulated cortisol, and endogenous ACTH concentrations were measured for each dog within 24 hours of admission and daily until death, euthanasia, or discharge from the ICU. Established reference ranges for healthy dogs were used for comparison. Survival prediction index (SPI) scores were calculated for each dog within 24 hours of admission. RESULTS: No significant difference was found between initial concentrations of basal cortisol, ACTH-stimulated cortisol, and endogenous ACTH in 13 dogs that survived and those in 7 dogs that died. High initial basal endogenous ACTH concentrations were correlated with subsequent high values. Low basal ACTH-stimulated cortisol concentrations were predictive of higher subsequent values. All basal and ACTH-stimulated cortisol concentrations were within or above the reference range in the 52 plasma samples collected from the 20 dogs during hospitalization. The SPI scores correlated with outcome (ie, alive or dead), but none of the plasma hormone concentrations correlated with SPI score or outcome. CONCLUSIONS AND CLINICAL RELEVANCE: Results indicate that none of the critically ill dogs in our study population developed adrenal insufficiency during hospitalization in the ICU.     

Effect of alternate-day prednisolone administration on hypophyseal-adrenocortical activity in dogs.

OBJECTIVE: To evaluate effect of alternate-day oral administration of prednisolone on endogenous plasma ACTH concentration and adrenocortical response to exogenous ACTH in dogs. ANIMALS: 12 Beagles. PROCEDURE: Dogs were allotted to 2 groups (group 1, 8 dogs treated with 1 mg of prednisolone/kg of body weight; group 2, 4 dogs given excipient only). During a 30-day period, blood samples were collected for determination of plasma ACTH and cortisol concentrations before, during, and after treatment with prednisolone. From day 7 to 23, prednisolone or excipient was given on alternate days. Sample collection (48-hour period with 6-hour intervals) was performed on days 1, 7, 15, 21, and 28; on other days, sample collection was performed at 24-hour intervals. Pre- and post-ACTH plasma cortisol concentrations were determined on days 3, 9, 17, 23, and 30. RESULTS: A significant difference was detected between treatment and time for group 1. Plasma ACTH concentrations significantly decreased for 18 to 24 hours after prednisolone treatment in group-1 dogs. At 24 to 48 hours, ACTH concentrations were numerically higher but not significantly different in group-1 dogs. Post-ACTH plasma cortisol concentration significantly decreased after 1 dose of prednisolone and became more profound during the treatment period. However, post-ACTH cortisol concentration returned to the reference range 1 week after prednisolone administration was discontinued. CONCLUSIONS AND CLINICAL RELEVANCE: Single oral administration of 1 mg of prednisolone/kg significantly suppressed plasma ACTH concentration in dogs for 18 to 24 hours after treatment. Alternate-day treatment did not prevent suppression, as documented by the response to ACTH.     

Effects of short-term trimethoprim-sulfamethoxazole administration on thyroid function in dogs

OBJECTIVE: To determine how rapidly trimethoprim-sulfamethoxazole affects serum total thyroxine (T4) and thyroid-stimulating hormone (TSH) concentrations in euthyroid dogs and how quickly hormone concentrations return to reference values following discontinuation of administration. DESIGN: Prospective study. ANIMALS: 7 healthy euthyroid dogs. PROCEDURE: Dogs were given trimethoprim-sulfamethoxazole (26.5 to 31.3 mg/kg [12 to 14.2 mg/lb], PO, q 12 h) for a maximum of 6 weeks. A CBC and Schirmer tear test were performed and serum total T4 and TSH concentrations were measured weekly. Administration of trimethoprim-sulfamethoxazole was discontinued if total T4 concentration was less than the lower reference limit and TSH concentration was greater than the upper reference limit or if persistent neutropenia developed. RESULTS: Six dogs had total T4 concentrations less than the lower reference limit within 3 weeks; T4 concentration was decreased after 1 week in 3 of these 6 dogs. In these 6 dogs, TSH concentration was greater than the upper reference limit within 4 weeks. In 1 dog, T4 and TSH concentrations were not affected, despite administration of trimethoprim-sulfamethoxazole for 6 weeks. Neutropenia developed in 4 dogs. In 1 dog, the neutropenia resolved while trimethoprim-sulfamethoxazole was still being administered. In the other 3, neutrophil counts returned to reference values 1 week after drug administration was discontinued. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that administration of trimethoprim-sulfamethoxazole at a dosage of 26.5 to 31.3 mg/kg, PO, every 12 hours can substantially alter serum total T4 and TSH concentrations and neutrophil counts in dogs within as short a time as a few weeks.     

Serum cortisol and thyroxine concentrations as predictors of death in critically ill puppies with parvoviral diarrhea

OBJECTIVE: To evaluate the role of adrenal and thyroid hormones in the prediction of death in a population of critically ill puppies with parvoviral diarrhea by measuring serial daily serum concentrations of cortisol and thyroxine. DESIGN: Prospective case-control study. ANIMALS: 57 critically ill puppies with parvoviral diarrhea admitted to the hospital and 17 clinically normal control puppies. PROCEDURES: Basal serum cortisol and thyroxine concentrations were measured for each dog with parvoviral diarrhea at admission (prior to treatment) and daily until death, euthanasia, or discharge. RESULTS: Median time between admission and death was 48 hours (ie, on day 3). Median serum cortisol concentration on day 1 (admission) in all dogs with parvoviral diarrhea (248 nmol/L) was significantly higher than in control dogs (77 nmol/L). No significant difference was found in the day 1 median serum cortisol concentration of 11 dogs that died (302 nmol/L) and 46 dogs that survived (238 nmol/L). A significantly higher median serum cortisol concentration was, however, found in nonsurvivor group dogs, compared with survivor group dogs, on days 2 and 3. Median serum thyroxine concentration on day 1 in dogs with parvoviral diarrhea was significantly lower than in control dogs (8.12 nmol/L vs 35 nmol/L, respectively). Median serum thyroxine concentration of nonsurvivor group dogs (4.4 nmol/L) was significantly lower than that of survivor group dogs (9.2 nmol/L) at admission and became even lower on days 2 and 3. CONCLUSIONS AND CLINICAL RELEVANCE: High serum cortisol and low serum thyroxine concentrations at 24 and 48 hours after admission were associated with death in dogs with parvoviral diarrhea.     

Effects of a mock ultrasonographic procedure on cortisol concentrations during low-dose dexamethasone suppression testing in clinically normal adult dogs

OBJECTIVE: To determine whether the stress of an ultrasonographic procedure would interfere with the suppressive effect of dexamethasone during a low-dose dexamethasone suppression test (LDDST) in healthy dogs. ANIMALS: 6 clinically normal adult dogs. PROCEDURE: In phase 1, an LDDST was performed 5 times at weekly intervals in each dog. Serum samples were obtained 0, 2, 4, 6, and 8 hours after dexamethasone injection. A mock 20-minute abdominal ultrasonographic examination was performed on all dogs at each time point during the LDDST on weeks 2 through 5. In phase 2, serum cortisol concentrations were measured before and immediately after a 20-minute mock abdominal ultrasonographic examination, as described for phase 1. RESULTS: We did not detect significant differences after dexamethasone injection when comparing median cortisol concentrations for weeks 2 to 5 (mock ultrasonographic procedure) with median concentration for week 1 (no mock ultrasonographic procedure). For 5 of the 6 dogs, cortisol concentrations after dexamethasone injection decreased to < 35.9 nmol/L after each mock ultrasonographic procedure and remained low for the duration of the LDDST. In phase 2, all dogs had significant increases in cortisol concentrations immediately after the mock ultrasonographic procedure. CONCLUSIONS AND CLINICAL RELEVANCE: A 20-minute mock abdominal ultrasonographic examination performed during LDDST did not alter results of the LDDST in most dogs. Cortisol concentrations measured immediately after a mock ultrasonographic examination were significantly increased. Ultrasonographic procedures should be performed a minimum of 2 hours before collection of samples that will be used to measure cortisol concentrations.     

Endotoxn-induced nonthyroidal illness in dogs

OBJECTIVE: To determine the effects of endotoxin administration on thyroid function test results and serum tumor necrosis factor-alpha (TNF-alpha) activity in healthy dogs. ANIMALS: 6 healthy adult male dogs. PROCEDURES: Serum concentrations of thyroxine (T4), 3,5,3'-triiodothyronine (T3), 3,3'5'-triiodothyronine (rT3), free T4 (fT4), and endogenous canine thyroid stimulating hormone (TSH), and TNF-alpha activity were measured before (day-1; baseline), during (days 0 to 3), and after (days 4 to 24) IV administration of endotoxin every 12 hours for 84 hours. RESULTS: Compared with baseline values, serum T3 concentration decreased significantly, whereas rT3 concentration increased significantly 8 hours after initial endotoxin administration. Serum T4 concentration decreased significantly at 8 and 12 hours after initiating endotoxin administration. Serum T4 concentration returned to reference range limits, then decreased significantly on days 6 to 12 and 16 to 20. Serum fT4 concentration increased significantly at 12, 24, and 48 hours after cessation of endotoxin treatment, compared with baseline values. Serum rT3 concentration returned to reference range, then decreased significantly days 5 and 7 after stopping endotoxin treatment. Serum TNF-alpha activity was significantly increased only 4 hours after initial endotoxin treatment, compared with baseline activity. CONCLUSIONS AND CLINICAL RELEVANCE: Endotoxin administration modeled alterations in thyroid function test results found in dogs with spontaneous nonthyroidal illness syndrome. A decrease in serum T4 andT3 concentrations and increase in serum rT3 concentration indicate impaired secretion and metabolism of thyroid hormones. The persistent decrease in serum T4 concentration indicates that caution should be used in interpreting serum T4 concentrations after resolution of an illness in dogs.     

Serial blood lactate concentrations in systemically ill dogs

BACKGROUND: Lactate concentration often is quantified in systemically ill dogs and interpreted based on human data. To our knowledge, there are no published clinical studies evaluating serial lactate concentrations as a prognostic indicator in ill dogs. OBJECTIVES: Our objective was to perform a prospective study, using multivariate analysis, to determine whether serial lactate concentrations were associated with outcome in ill dogs requiring intravenous fluids. METHODS: Eighty sick dogs had lactate concentrations evaluated, using an analyzer that measures lactate in the plasma fraction of heparinized whole blood, at 0 hours and 6 hours after initiation of treatment. Severity of illness and outcome (survivor, nonsurvivor) were determined by reviewing the patient's record 2 weeks after admission. Lactate concentrations, age, body weight, gender, and severity of illness were evaluated using multivariate analysis to determine their effects on outcome. RESULTS: Dogs with lactate concentrations greater than the reference interval at 6 hours were 16 times (95% confidence interval = 2.32-112.71 times, P <.01) more likely not to survive compared to dogs with lactate concentrations within the reference interval. Lactate concentrations above the reference interval at 0 hours were not significantly related to outcome. However, hyperlactatemia that did not improve by > or = 50% within 6 hours was significantly associated with mortality (P = .024). CONCLUSION: Dogs with a lactate concentration higher than the reference interval at 6 hours were more likely not to survive. These results indicate an association between lactate concentration and outcome and emphasize the importance of serial lactate concentrations in evaluating prognosis.     

Estimating adrenal cortical function in dogs with ACTH.

The peripheral blood response to intramuscular injection of 10 units ACTH in dogs was investigated because no experimental evidence for the standardization of this procedure for clinical use was available. Following the injection of ACTH in sodium chloride solution, neutrophilia, monocytosis, eosinopenia, and lymphopenia occurred. With the exception of eosinopenia, the greatest change in the concentration of each cell type in peripheral blood occurred between 2 and 4 hours post injection. The maximum change in eosinophil numbers occurred between 4 and 6 hours post injection. When all cell types were considered, 4 hours post injection was the most suitable time to measure the cellular response in peripheral blood in dogs which respond to ACTH. The data indicate that change in the ratio of neutrophils to lymphocytes (N/L) prior to and at 2 to 4 hours after ACTH injection in normal dogs was a sensitive index of response and occured sooner than eosinopenia. The extent of change in the N/L ratio was such that accuracy in interpretation could be obtained by counting as few as 40 cells.     

Evaluation of postceliotomy peritoneal drain fluid volume, cytology, and blood-to-peritoneal fluid lactate and glucose differences in normal dogs

Objective: To describe peritoneal drain fluid volume, fluid cytology, and blood‐to‐peritoneal fluid lactate and glucose concentration differences after exploratory celiotomy in normal dogs. Study Design: Prospective study. Animals: Healthy Beagle dogs (n=10). Methods: After exploratory celiotomy, a peritoneal drain was placed, and peritoneal fluid was recorded every 6 hours for 7 days. Fluid was submitted for cytologic examination, and fluid and blood glucose and lactate concentrations were recorded every 12 hours. On day 7, drains were removed and drain tips submitted for aerobic bacterial culture. Results: Mean peritoneal fluid volume decreased from 2.8 mL/kg/day (day 1) to 0.6 mL/kg/day (day 7). All dogs had degenerate neutrophils in peritoneal fluid throughout the 7 days. Four dogs developed contaminated drains. Blood‐to‐peritoneal glucose concentration differences>20 mg/dL occurred after day 4. By day 7, 5 of 7 dogs with patent drains had blood‐to‐peritoneal lactate concentration differences70% of dogs had differences consistent with septic peritonitis each day. Postoperative blood‐to‐peritoneal fluid glucose and lactate difference may not be reliable indicators of septic peritonitis when evaluating abdominal fluid collected with closed suction drains.     

Comparison of the biological activity of recombinant human thyroid-stimulating hormone with bovine thyroid-stimulating hormone and evaluation of recombinant human thyroid-stimulating hormone in healthy dogs of different breeds

OBJECTIVE: To evaluate whether use of recombinant human (rh) thyroid-stimulating hormone (TSH) induces equivalent stimulation, compared with bovine TSH (bTSH), and to evaluate activity of rhTSH in dogs of various large breeds. ANIMALS: 18 healthy research Beagles and 20 healthy client-owned dogs of various breeds with body weight > 20 kg. PROCEDURES: The 18 Beagles were randomly assigned to 3 groups, and each dog received either 75 microg of rhTSH, IM or IV, or 1 unit of bTSH, IM, respectively, in a crossover design. The 20 client-owned dogs received 75 microg of rhTSH, IV. Blood samples were taken before and 6 hours after TSH administration for determination of total serum thyroxine (T(4)) concentration. Additional blood samples were taken after 2 and 4 hours in Beagles that received rhTSH, IM. RESULTS: There was a significant increase in T(4) concentration in all dogs, but there were no differences between values obtained after administration of bTSH versus rhTSH or IV versus IM administration of rhTSH. Although there was a significant difference in age and body weight between Beagles and non-Beagles, there was no difference in post-TSH simulation T(4) concentration between the 2 groups. CONCLUSIONS AND CLINICAL RELEVANCE: Results indicated an equivalent biological activity of rhTSH, compared with bTSH. Use of 75 microg of rhTSH, IV, did not induce a different magnitude of stimulation in large-breed dogs, compared with Beagles. Euthyroidism was confirmed if post-TSH simulation T(4) concentration was > or = 2.5 microg/dL and at least 1.5 times basal T(4) concentration.     

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)