The effect of capromorelin on glycemic control in healthy dogs.

Capromorelin is a ghrelin-receptor agonist widely used as an appetite stimulant in dogs. Capromorelin disrupts glucose homeostasis in cats but information regarding its effects on canine glucose homeostasis is lacking. The study objective was to evaluate the effect of capromorelin on glucose homeostatic mechanisms in healthy dogs. Eight clinically healthy client-owned adult dogs were enrolled in this prospective, cross-over, placebo-controlled study. Dogs were randomized to receive capromorelin (Entyce, 3 mg/kg) or placebo, q24h for 3 d. A wk later, treatments were crossed over. Interstitial glucose (IG) concentrations were measured using a flash glucose monitoring system throughout. On d 1 of each treatment, blood glucose (BG), insulin, glucagon, glucose-dependent insulinotropic peptide (GIP), and glucagon-like peptide-1 (GLP-1) concentrations were measured before drug administration, then before and 30-120 min after feeding a glucose-rich diet (Ensure Plus, 21 kcal/kg). Data were analyzed as a 2-period crossover design using generalized least squares estimation. Capromorelin administration increased mean 48 h IG by10% and mean BG by 20% at 90 and 120 min post-prandially (P < 0.0001). Post-prandially, there was a time-by-treatment effect for insulin (P = 0.03) and GIP (P = 0.0002) because capromorelin doubled geometric mean insulin concentrations at 120 min and increased geometric mean GIP concentrations more rapidly than after placebo. There were no differences in glucagon or GLP-1 concentrations between treatment groups. The increase in post-prandial blood glucose was not the result of overt suppression of incretin hormone secretion. There was also no suppressive effect of capromorelin on insulin.

Dietary cation-anion difference may explain why ammonium urate nephrolithiasis occurs more frequently in common bottlenose dolphins () under human care than in free-ranging common bottlenose dolphins.

Ammonium urate nephrolithiasis frequently develops in common bottlenose dolphins () managed under human care but is rare in free-ranging common bottlenose dolphins. In other species, the dietary cation-anion difference (DCAD) can affect ammonium urate urolith formation by increasing proton excretion as ammonium ions. Therefore, differences in diet between the 2 dolphin populations could affect urolith formation, but the DCAD of most species consumed by free-ranging and managed dolphins is unknown. To compare the nutrient composition of diets consumed by free-ranging and managed bottlenose dolphins, samples ( = 5) of the 8 species of fish commonly consumed by free-ranging bottlenose dolphins in Sarasota Bay, FL, and the 7 species of fish and squid commonly fed to managed bottlenose dolphins were analyzed for nutrient content. Metabolizable energy was calculated using Atwater factors; the DCAD was calculated using 4 equations commonly used in people and animals that use different absorption coefficients. The nutrient composition of individual species was used to predict the DCAD of 2 model diets typically fed to managed common bottlenose dolphins and a model diet typically consumed by common bottlenose dolphins in Sarasota Bay. To mimic differences in postmortem handling of fish for the 2 populations of bottlenose dolphins, "free-ranging" samples were immediately frozen at -80°C and minimally thawed before analysis, whereas "managed" samples were frozen for 6 to 9 mo at -18°C and completely thawed. "Free-ranging" species contained more Ca and P and less Na and Cl than "managed" fish and squid species. As a consequence, the DCAD of both model managed dolphin diets obtained using 3 of the 4 equations was much more negative than the DCAD of the model free-ranging bottlenose dolphin diet ( < 0.05). The results imply that managed bottlenose dolphins must excrete more protons in urine than free-ranging bottlenose dolphins, which will promote nephrolith formation. The nutrient composition of the free-ranging bottlenose dolphin diet, determined for the first time here, can be used as a guide for feeding managed bottlenose dolphins, but research in vivo is warranted to determine whether adding more cations to the diet will prevent urolith formation in managed dolphins.

A Targeted Metabolomics Assay to Measure Eight Purines in the Diet of Common Bottlenose Dolphins, Tursiops truncatus.

Bottlenose dolphins managed under human care, human beings and Dalmatian dogs are prone to forming urate uroliths. Limiting dietary purine intake limits urate urolith formation in people and dogs because purines are metabolized to uric acid, which is excreted in urine. Managed dolphins develop ammonium urate nephroliths, whereas free-ranging dolphins do not. Free-ranging dolphins consume live fish, whereas managed dolphins consume different species that have been stored frozen and thawed. Differences in the purine content of fish consumed by dolphins under human care versus in the wild may be responsible for the difference in urolith prevalence. Commercially available purine assays measure only four purines, but reported changes in purines during frozen storage suggest that a wider range of metabolites should be measured when comparing fresh and stored fish. A method using high performance liquid chromatography with tandem mass spectrometry was developed to quantify eight purine metabolites in whole fish and squid commonly consumed by dolphins. The coefficient of variation within and among days was sometimes high for purines present in small amounts but was acceptable (≤ 25%) for guanine, hypoxanthine, and inosine, which were present in high concentrations. This expanded assay identified a total purine content up to 2.5 times greater than the total that would be quantified if only four purines were measured. Assuming additional purines are absorbed, these results suggest that additional purine metabolites should be measured to better understand the associated risk when fish or other purine-rich foods are consumed by people or animals prone to developing uroliths.

Comparison between Urine Protein: Creatinine Ratios of Samples Obtained from Dogs in Home and Hospital Settings.

BACKGROUND: The urine protein:creatinine ratio (UPC) is used to quantify urine protein excretion and guide recommendations for monitoring and treatment of proteinuria. HYPOTHESIS/OBJECTIVES: Home urine samples will have lower UPCs than hospital samples. The objectives were to compare UPCs of samples collected in each setting and to determine whether environment of sample collection might affect staging, monitoring or treatment recommendations. ANIMALS: Twenty-four client-owned dogs. METHODS: Prospective, nonmasked study. Clients collected a urine sample from their dog at home and a second sample was collected at the hospital. Dogs receiving corticosteroids or angiotensin-converting enzyme inhibitors were excluded, as were those with urine samples of inadequate volume, no protein on dipstick analysis, or active urine sediment. Samples were refrigerated after collection, dipstick and sediment evaluations were completed and each sample was frozen at -80°C within 12 hours. UPCs were performed on frozen samples within 2 months. RESULTS: From 81 paired samples, 57 were excluded. Of the remaining 24, 12/24 (50%) had higher hospital sample UPCs, 9/24 (38%) had identical UPCs, and 3/24 (12%) had lower hospital UPCs. The UPCs of hospital samples were higher than home samples for the total population (P = .005) and the subset with UPC > 0.5 (P = .001). CONCLUSIONS: Setting and related circumstances of urine collection in dogs is associated with UPC differences; results are usually higher in hospital than in home samples. This difference has the potential to affect clinical interpretation.

Nutrient and metal analyses of Chinese herbal products marketed for veterinary use.

Many Chinese herbs and herbal mixtures are fed to domestic animals for their reputed medicinal properties. These herbs could contribute to the intake of essential nutrients and toxic metals, but their composition is mostly unknown. The purpose of this study was to measure major nutrient (crude protein, crude fat, carbohydrate, fibre) and mineral (Ca, P, Mg, K, Na, Fe, Zn, Cu, Mn, Mo, S, Al, Cd, Ni, Pb) concentrations in samples of fourteen combination formulas labelled for veterinary use and commonly administered to horses and dogs. Three single herbs, Bupleurum chinense, Curcuma zedoaria and Astragalus membranaceus, each obtained from several sources, and Yunnan Baiyao, a proprietary hemostatic mixture, were also analysed. Proximate analyses and some mineral concentrations differed (p < 0.05) among single herbs, and high concentrations of several minerals were detected in some herbal combinations. Those containing the highest concentrations [g/kg dry matter (DM)] of calcium (92.4), iron (2.6) and manganese (0.28) could provide >38%, 142% and 96%, respectively, of recommended allowances in adult dogs, and >13%, 122% and 2%, respectively, of maintenance requirements in horses, at the maximum labelled dose assuming complete availability. Concentrations of cadmium, nickel and lead were below published oral tolerance levels. Aluminium concentrations (median 380, maximum 920 mg/kg DM) were higher than has been previously reported in Chinese herbs. These nutrient analyses suggest that herbal combinations marketed to veterinarians, when fed at the maximal labelled dose, are unlikely to produce clinically relevant changes in the dietary intake of essential nutrients. However, small amounts of non-essential contaminant minerals are present in some formulas, and further research is necessary to understand the significance of this finding.

Effect of creatine monohydrate on cardiac function in a rat model of endotoxemia.

BACKGROUND: Reports have attributed cardiac failure during acute models of endotoxemia to a lack of high-energy phosphates. This study was undertaken to investigate whether creatine (Cr) administered during perfusion could enhance myocardial protection and improve recovery of cardiac function in a rat model of endotoxemia. METHODS: Acute endotoxemia was induced in rats by a bolus injection of Escherichia coli endotoxin (LPS: 4 mg/kg, ip) while control rats were injected with an equal volume of 0.9% normal saline. To assess the adequacy of energy metabolism, freeze-clamped hearts were obtained from animals to study the concentrations of endogenous ATP, phosphocreatine (PCr), inorganic phosphate (P(i)), and intracellular pH by (31)P-cryomagnetic resonance spectroscopy. In a separate experiment, isolated hearts were perfused via a Langendorff column with Krebs-Henseleit buffer containing different concentrations of creatine monohydrate (1, 3, or 10 mM). Cardiac performance was evaluated via a paced (300 bpm) isovolumetric balloon preparation. Measurements of cardiac function including left ventricular developed pressure (LVDP), the maximum rates of ventricular pressure rise (LV +dP/dt) and fall (LV -dP/dt), and coronary flow were made for both LPS and saline-treated animals. RESULTS: High-energy phosphate ratios of PCr/ATP and PCr/P(i) in hearts declined significantly at 4 h after endotoxin treatment. As anticipated, LVDP and LV +dP/dt(max) at a given preload and heart rate were significantly (P < 0.05) lower at 4 h when measured at the same time point. The functional recovery of these parameters was not improved by the addition of creatine monohydrate to the perfusion buffer. Creatine produced a significant (P < 0.05) negative inotropic effect in hearts from saline-treated animals. The LVDP was reduced by 30% at the lowest concentration and by 50% at the highest concentration of creatine monohydrate. Furthermore, creatine significantly (P < 0.05) reduced LV -dP/dt(max) in both saline and LPS-treated rats. These data demonstrate that exogenous creatine does not contribute to myocardial preservation in endotoxemia. CONCLUSIONS: Energy stores in the rat heart decline early in endotoxemia accompanied by reduced myocardial performance, suggesting that the ability of the heart to perform mechanical work is impaired. Cardiac dysfunction in an acute model of endotoxemia was not improved with exogenous creatine during perfusion. Creatine's effects were primarily lusitropic by delaying the onset of myocardial relaxation in all hearts. The deleterious effects of exogenous creatine monohydrate in normal hearts should be examined in future experimental studies.

Serum ascorbic acid concentrations in previously unsupplemented greyhounds after administration of a single dose of ascorbic acid intravenously or per os.

Plasma vitamin C concentrations (mean + SD) were measured after a large (1 g) dose of vitamin C was administered orally or intravenously to each of four trained greyhounds in a randomized cross-over design. Concentrations increased (p<0.05) for 2 h but returned to baseline by 6 h after supplementation. Peak concentrations were greater (p<0.01) after intravenous than oral administration (6.1+/-1.2 vs. 0.54+/-0.23 mg/dl). This suggests that vitamin C must be administered many times daily to maintain plasma concentrations above normal.

Postprandial venous ammonia concentrations in the diagnosis of hepatobiliary disease in dogs.

A postprandial ammonia tolerance test (PPATT) was performed on normal dogs and dogs with signs that suggested they may have liver disease. All dogs underwent transcolonic scintigraphy, liver biopsy, or both and were assigned to extrahepatic disease, primary hepatocellular, and congenital portosystemic vascular anomalies (PSVA) groups. Each dog was fed a chicken and rice diet providing 25% of its estimated daily metabolizable energy requirement (MER) as an ammonia challenge. This is practical in patients with liver disease because ammonium chloride administration often causes vomiting or ammonia toxicity. Venous ammonia concentrations were measured before feeding and every 2 hours after feeding for 8 hours. No difference in mean ammonia concentrations between dogs with extrahepatic disease and control dogs was found. Therefore, the specificity of the PPATT was 100%. Dogs with hepatocellular disease showed no change in mean ammonia concentration at any time point, before or after feeding, but sensitivity was greatest when venous ammonia was measured 6 hours after feeding (sensitivity before feeding, 28%, and after feeding, 36%). Among dogs with congenital PSVA, mean ammonia concentrations were higher than the reference range at all time points before and after feeding, and peak mean ammonia concentration occurred 6 hours after feeding. In this group, the sensitivity of the PPATT was 81% before feeding and 91% 6 hours after feeding. This study demonstrates that the measurement of venous ammonia concentration is a useful test to detect congenital PSVA, and the sensitivity of the test may be improved by sampling 6 hours after feeding. The PPATT has poor sensitivity in detecting primary hepatocellular disease.

Intestinal permeability testing using lactulose and rhamnose: a comparison between clinically normal cats and dogs and between dogs of different breeds.

In the experiment reported here, the lactulose/rhamnose urinary excretion test was used to compare intestinal permeability between four breeds of healthy adult dogs and a group of healthy adult cats. A significant difference in permeability was found between dogs and cats (P <0.001) and between different breeds of dogs (P <0.005). The range of urinary lactulose/rhamnose ratios in the dogs in this study (0.07-0.61) was wider than previously reported (0.03-0.12). The mean value for dogs was 0.19. The range in cats was 0.41-1.25 and the mean 0.52. The results of this study suggest that breed or some other factor such as environment, diet or sexual status as well as species should be taken into account when assessing intestinal permeability using the lactulose/rhamnose urinary excretion test.

The effect of texturized vegetable protein from soy on nutrient digestibility compared to beef in cannulated dogs.

Texturized vegetable protein from soy (TVP) is widely used in canned dog foods, but its nutritional value remains in doubt. This study compared apparent prececal and total intestinal digestibility when four canned diets containing reciprocal proportions of protein from TVP (0 to 57%) and from beef (100 to 43%) were fed to eight cannulated dogs. As dietary TVP increased, the following linear changes were observed (P < 0.05): prececal and total intestinal protein digestibility decreased slightly from 77 to 71% and 86 to 80%, respectively; prececal amino acid digestibility decreased in parallel with protein; prececal carbohydrate digestibility decreased markedly from 80% to 62% and carbohydrate disappearance in the large intestine increased from 8 to 22%; prececal sodium digestibility decreased markedly (from 37 to 4%); and prececal potassium digestibility decreased (from 93 to 85%). Total intestinal digestibility of sodium and potassium decreased little (from 97 to 95% and from 98 to 97%, respectively); fecal mass and water content increased markedly (from 98 to 174 g/d and from 61 to 72%, respectively); and fat digestibility was unaffected. Prececal phosphorus digestibility from two diets containing TVP was lower than that from the all-beef diet (13 and 17%, vs 26%, P < 0.05). In conclusion, TVP is a useful source of protein in canine canned diets because amino acids from TVP are almost as digestible as those from beef in the canine intestine. Nevertheless, soy carbohydrate is poorly digested and large amounts of TVP inhibit small intestinal electrolyte digestibility and increase fecal water content.

Effect of alpha-tocopheryl acetate supplementation on vitamin E concentrations in Greyhounds before and after a race.

OBJECTIVES: To determine effect of alpha-tocopherol supplementation on serum vitamin E concentrations in Greyhounds before and after a race. ANIMALS: 8 adult racing Greyhounds. PROCEDURE: Dogs were given 2 capsules of alpha-tocopheryl acetate (total, 680 units [0.5 g]) with food that contained < or = 15 mg of vitamin E/kg each morning for 7 days. Dogs were exercised in a 30 X 30-m grass paddock for 15 minutes twice a day and raced for 500 m twice a week. Blood samples were collected before and 5 minutes after a race, before supplementation was begun, and after 7 days of supplementation. Blood and diet samples were analyzed for tocopherols and alpha-tocopheryl acetate. RESULTS: Before supplementation, serum alpha-tocopherol concentration after racing (mean +/- SD, 6.7 +/- 2.4 mg/L ) was significantly lower than before racing (12.2 +/- 3.1 mg/L). After supplementation, alpha-tocopherol concentrations were significantly higher overall, although values obtained before (26.6 +/- 5.2 mg/L) and after (29.8 +/- 3.6 mg/L) racing were not significantly different. CONCLUSIONS AND CLINICAL RELEVANCE: Supplementation with alpha-tocopheryl acetate increased serum alpha-tocopherol concentrations and eliminated the decrease in alpha-tocopherol concentration that was detected after a race, which may decrease oxidation during exercise and improve performance or recovery.

Effect of increased dietary protein and decreased dietary carbohydrate on performance and body composition in racing Greyhounds.

OBJECTIVE: To determine effects of increased dietary protein and decreased dietary carbohydrate on hematologic variables, body composition, and racing performance in Greyhounds. ANIMALS: 8 adult Greyhounds. PROCEDURE: Dogs were fed a high-protein (HP; 37% metabolizable-energy [ME] protein, 33% ME fat, 30% ME carbohydrate) or moderate-protein (MP; 24% ME protein, 33% ME fat, 43% ME carbohydrate) extruded diet for 11 weeks. Dogs subsequently were fed the other diet for 11 weeks (crossover design). Dogs raced a distance of 500 m twice weekly. Rectal temperature, hematologic variables before and after racing, plasma volume, total body water, body weight, average weekly food intake, and race times were measured at the end of each diet period. RESULTS: When dogs were fed the MP diet, compared with the HP diet, values (mean +/- SD) differed significantly for race time (32.43 +/- 0.48 vs 32.61 +/- 0.50 seconds), body weight (32.8 +/- 2.5 vs 32.2 +/- 2.9 kg), Hct before (56 +/- 4 vs 54 +/- 6%) and after (67 +/- 3 vs 64 +/- 8%) racing, and glucose (131 +/- 16 vs 151 +/- 27 mg/dl) and triglyceride (128 +/- 17 vs 104 +/- 28 mg/dl) concentrations after racing. CONCLUSIONS AND CLINICAL RELEVANCE: Greyhounds were 0.18 seconds slower (equivalent to 0.08 m/s or 2.6 m) over a distance of 500 m when fed a diet with increased protein and decreased carbohydrate. Improved performance attributed to feeding meat to racing Greyhounds apparently is not attributable to increased dietary protein and decreased dietary carbohydrate.

Effects of racing and training on serum thyroid hormone concentrations in racing Greyhounds.

OBJECTIVES: To determine the effects of racing and training on serum thyroxine (T4), triiodothyronine (T3), and thyroid stimulating hormone (TSH) concentrations in Greyhounds. ANIMALS: 9 adult racing Greyhounds. PROCEDURE: Serum thyroid hormone concentrations were measured before and 5 minutes after a race in dogs trained to race 500 m twice weekly for 6 months. Resting concentrations were measured again when these dogs had been neutered and had not raced for 3 months. Postrace concentrations were adjusted relative to albumin concentration to allow for effects of hemoconcentration. Thyroid hormone concentrations were then compared with those of clinically normal dogs of non-Greyhound breeds. RESULTS: When adjusted for hemoconcentration, total T4 concentrations increased significantly after racing and TSH concentrations decreased; however, there was no evidence of a change in free T4 or total or free T3 concentrations. Resting total T4 concentrations increased significantly when dogs had been neutered and were not in training. There was no evidence that training and neutering affected resting TSH, total or free T3, or free T4 concentrations. Resting concentrations of T3, TSH, and autoantibodies against T4, T3, and thyroglobulin were similar to those found in other breeds; however, resting free and total T4 concentrations were lower than those found in other breeds. CONCLUSIONS AND CLINICAL RELEVANCE: Except for total T4, thyroid hormone concentrations in Greyhounds are affected little by sprint racing and training. Greyhounds with low resting total and free T4 concentrations may not be hypothyroid.

Maintenance energy requirements and the effect of diet on performance of racing Greyhounds.

OBJECTIVES: To determine maintenance energy requirements and effect of diet on performance of racing Greyhounds. ANIMALS: 7 adult racing Greyhounds. PROCEDURE: Dogs were fed a higher fat and protein (HFP) or a lower fat and protein (LFP) diet for 8 weeks in a crossover design. Dogs were exercised for 15 minutes twice daily in a paddock and raced 500 m twice weekly. Blood gas, hematologic, and serum biochemical analyses were performed before and after racing, and race times were compared at the end of each diet period. RESULTS: Mean race time was significantly shorter (32.81+/-0.65 seconds vs. 33.05+/-0.71 seconds), and mean racing speed over 500 m was significantly faster (15.25+/-0.30 vs. 15.13+/-0.30 m x s(-1)) when dogs were fed the HFP diet than when they were fed the LFP diet. Diet had little or no effect on results of blood gas, hematologic, and serum biochemical analyses, except that Hct was 4% greater before and after racing when the HFP diet was fed than when the LFP diet was fed. Mean SD metabolizable energy intake from weeks 1 through 16 was 155+/-9 kcal x kg(-0.75) x d(-1). CONCLUSIONS AND CLINICAL RELEVANCE: Racing Greyhounds ran faster when fed a diet containing higher fat and protein and lower carbohydrate contents. Their maintenance metabolizable energy requirement was slightly higher than that of moderately active dogs.

The effect of texturized vegetable protein containing soy carbohydrate on oroileal transit of chromic oxide in cannulated dogs.

Texturized vegetable protein (TVP) from soy is widely used in dog foods but contains indigestible carbohydrate, which may affect intestinal transit. This study was conducted to determine whether TVP affects oroileal transit of the marker chromic oxide (Cr2O3). Four canned diets with Cr2O3 added were fed to eight cannulated mixed-breed dogs in a Latin-square design. The four diets contained reciprocal proportions of protein from TVP (0 to 57%) and from beef (100 to 43%). Ileal effluent was collected during wk 3 of each diet period, prececal apparent digestibility was measured on d 1 to 3 (eight dogs), and rate of appearance of Cr2O3 and chyme was measured on d 4 (six dogs). There was a postprandial delay before any chyme or Cr2O3 was collected, but from 2 to 8 h postprandially the rate of excretion was almost constant (approximately 11%/h). As TVP increased, mean prececal digestibility of protein and carbohydrate decreased from 77 to 71% and from 80 to 62%, respectively. Chyme excretion from 2 to 8 h postprandially increased from 5.8 to 8.3 g DM/h (P < .0001) as TVP increased but times for transit of Cr2O3 and appearance of chyme (as percentage total collected/hour) did not change. Mean times to first appearance and 15, 50, and 95% excretion were 76, 160, 347, and 707 min for Cr2O3 and 60, 147, 338, and 712 min for chyme, respectively. Mean Cr2O3 recovery was 93%. In conclusion, small intestinal transit of Cr2O3 was unaffected by increasing dietary TVP despite marked changes in carbohydrate digestibility.

Comparison of plasma benzodiazepine concentrations following intranasal and intravenous administration of diazepam to dogs.

OBJECTIVE: To determine whether plasma concentrations of benzodiazepines (BDZ) in dogs following intranasal (IN) administration of diazepam are comparable to concentrations following IV administration. ANIMALS: 6 (4 male, 2 female) healthy adult Greyhounds. PROCEDURE: Dogs were randomly assigned to 2 groups of 3 dogs in a crossover design. Diazepam (0.5 mg/kg of body weight) was administered intravenously to dogs in group 1 and intranasally to dogs in group 2. Blood was collected from the jugular vein of each dog into tubes containing lithium heparin before and 3, 6, 9, 12, 15, 20, 30, 60, 120, 240, and 480 minutes following diazepam administration. After a 4-day washout period, dogs in group 1 received diazepam intranasally, dogs in group 2 received diazepam intravenously, and blood was again collected. Plasma concentration of BDZ was determined by use of a fluorescence polarization immunoassay. RESULTS: Mean (+/- SD) peak plasma concentration of BDZ following IV administration (1,316 +/- 216 microg/L) was greater than that following IN administration (448 +/- 41 microg/L). Time to peak concentration was < or = 3 minutes following IV administration and 4.5 +/- 1.5 minutes following IN administration. Mean bioavailability of BDZ following IN administration was 80 +/- 9%. CONCLUSIONS AND CLINICAL RELEVANCE: Diazepam is rapidly and efficiently absorbed following IN administration of the parenteral formulation. Plasma concentrations match or exceed the suggested therapeutic concentration (300 microg/L). Intranasal administration of diazepam may be useful for treatment of seizures in dogs by owners or when intravenous access is not readily available.

Gastrointestinal volatile fatty acid concentrations and pH in cats.

OBJECTIVE: To measure volatile fatty acid (VFA) concentrations and pH in the gastrointestinal tracts of healthy adult cats fed a commercial dry cat food. ANIMALS: 14 cats. PROCEDURE: The gastrointestinal tracts were excised immediately after euthanasia and divided into 6 sections (stomach, duodenum, jejunum, ileum, proximal portion of the colon, and distal portion of the colon). Luminal contents were collected from each segment, pH was measured, and contents were centrifuged. The supernatant was analyzed for acetate, proprionate, butyrate, isobutyrate, valerate, and isovalerate concentrations by use of gas chromatography. RESULTS: Mean total VFA concentrations were lowest in the stomach (20 mmol/L); increased through the duodenum, jejunum, and ileum (30, 29, and 41 mmol/L, respectively); and were greatest in the proximal and distal portions of the colon (109 and 131 mmol/L, respectively). Estimated mean total VFA amounts were low (<600 micromol) throughout all segments of the gastrointestinal tract; pH values increased from the stomach through the ileum and subsequently decreased in the colon. CONCLUSIONS AND CLINICAL RELEVANCE: Total VFA concentrations in the colon were comparable to values reported for the forestomach of ruminants and large intestines of monogastric animals, whereas values in the small intestine were higher than reported for other species. Total VFA amounts were low, consistent with the short, nonvoluminous gastrointestinal tract of carnivores. Luminal pH varied throughout the gastrointestinal tract in a pattern similar to other monogastric animals. Volatile fatty acids probably contribute minimal metabolic energy in cats but may be important in the maintenance of local mucosal health.