OBJECTIVE To determine serum and tissue concentrations of gallium (Ga) after oral administration of gallium nitrate (GaN) and gallium maltolate (GaM) to neonatal calves. ANIMALS 8 healthy neonatal calves. PROCEDURES Calves were assigned to 1 of 2 groups (4 calves/group). Gallium (50 mg/kg) was administered as GaN or GaM (equivalent to 13.15 mg of Ga/kg for GaN and 7.85 mg of Ga/kg for GaM) by oral gavage once daily for 5 days. Blood samples were collected 0, 0.25, 0.5, 1, 2, 4, 8, 12, and 24 hours after Ga administration on day 1; 4 and 24 hours after Ga administration on days 2, 3, and 4; and 4, 12, and 24 hours after Ga administration on day 5. On day 6, calves were euthanized and tissue samples were obtained. Serum and tissue Ga concentrations were measured by use of mass spectrometry. RESULTS Data were adjusted for total Ga dose, and comparisons were made between the 2 groups. Calves receiving GaM had a significantly higher dose-adjusted area under the curve and dose-adjusted maximum serum Ga concentration than did calves receiving GaN. Despite receiving less Ga per dose, calves receiving GaM had tissue Ga concentrations similar to those for calves receiving GaN. CONCLUSIONS AND CLINICAL RELEVANCE In this study, calves receiving GaM had significantly higher Ga absorption than did calves receiving GaN. These findings suggested that GaM might be useful as a prophylactic agent against Mycobacterium avium subsp paratuberculosis infection in neonatal calves.

Serum retinol, retinyl palmitate, and total vitamin A concentrations, and jejunoileal morphology were examined in neonatal calves infected with Cryptosporidium parvum. Group-1 calves served as noninfected controls and, after an adjustment period, were given 50 ml of saline solution IV every 12 hours for 6 days. Group-2 calves were inoculated with 10(7) C parvum oocysts and, after the onset of diarrhea, were given 50 ml of saline solution IV every 12 hours for 6 days. Group-3 calves were inoculated with 10(7) C parvum oocysts and, after the onset of diarrhea, were treated with difluoromethylornithine (DFMO, 200 mg/kg of body weight IV, q 12 h) for 6 days. Group-4 calves were naturally infected with C parvum. Jejunoileal biopsy specimens were excised from calves of groups 1-3 at 3 and again at 15 to 16 days of age. During the course of diarrhea and 3 days after saline or DFMO administration, water-miscible retinyl palmitate was administered orally (2,750 micrograms/kg) to each calf in each group. Cryptosporidium parvum infection was associated with significant (P < 0.05) reduction in postadministration serum retinol, retinyl palmitate, and total vitamin A concentrations in calves of groups 2, 3, and 4. Cryptosporidium parvum infection caused significant (P < 0.05) reduction in villus height. Decreased villus height, villus blunting and fusion, and attenuation of the intestinal mucosa were associated with reduced absorption of vitamin A, as indicated by lower peak postadministration retinyl palmitate concentration in C parvum-infected calves. Intravenous administration of DFMO to group-3 calves did not improve retinol absorption. Vitamin A should be provided parenterally to young calves with enteric cryptosporidiosis in an attempt to avoid depletion of concurrent low liver vitamin A reserves.

Techniques for the measurement of breath hydrogen excretion have been evaluated in dogs and the breath hydrogen test has been shown to be useful for clinical diagnosis and as a research tool. A simple method was developed for collection of expired air and measurement of breath hydrogen concentrations in cats, which enabled demonstration of carbohydrate malassimilation. Breath hydrogen concentrations were measured in healthy cats after food was withheld and after xylose and lactulose administration. Breath samples were collected by use of an open flow system with the cat confined in an acrylic plastic chamber. Breath hydrogen excretion did not exceed 0.53 ml of hydrogen/h in cats not fed. Breath hydrogen concentrations after the ingestion of xylose, a pentose sugar given orally at 0.75 g/kg of body weight, were not significantly higher from those of cats not fed. After ingestion of 3.35 g of lactulose, a nonabsorbable disaccharide, breath hydrogen excretion increased and breath hydrogen concentrations were significantly higher by 45 minutes (P < 0.05) and 60 minutes (P < 0.01) from breath hydrogen concentrations measured in cats not fed and after xylose administration. Administration of lactulose at an increased dosage resulted in further significant (P < 0.01) increases in breath hydrogen excretion. In this study, mouth-to-cecum transit times were variable. A mean +/- SEM mouth-to-cecum transit time of 86 +/- 6 minutes was calculated from measurement of breath hydrogen excretion after oral administration of 3.35 g of lactulose. Measurements of breath hydrogen concentrations after breath collection by open-flow and closed-flow sampling systems were highly correlated and both variables followed log-normal distributions. The dilution of expired air by the open flow sampling system was not excessive and the results of this correlation study suggested that differences in the assimilation of xylose in healthy cats and dogs may well exist.

The uptake of colostral IgG and IgM, their serum half-lives, and the rates of endogenous synthesis of IgG and IgM were evaluated in 6 newborn foals fed bovine colostrum (principals) and 6 foals allowed to suckle their dams (controls). The principal foals were fed 400 ml of bovine colostrum (IgG, 10,000 mg/dl and IgM, 200 mg/dl) at 2-hour intervals, from 2 to 20 hours after foaling (total dose, 4 L). Serum IgG and IgM concentrations were determined by single radial immunodiffusion from birth to 98 days of age. At foaling, principal foals had no detectable serum equine IgG, but 1 control foal had serum equine IgG of 185 mg/dl. AFter ingestion of colostrum, there was no significant difference in the maximal serum bovine IgG concentration (range, 1,350 to 3,300 mg/dl) in the principal foals, and maximal serum equine IgG concentration (range, 500 to 6,000 mg/dl). The calculated biological bovine and equine IgG half-life in the principal and control groups was 9.4 and 26 days, respectively. Endogenous IgG synthesis was first detected in 1 principal foal at 3 days of age, but was detected first between 28 and 42 days in the other principal foals. Starting on day 56 there was no significant difference in serum equine IgG concentration between groups. At foaling, foals in both groups had low equine IgM concentrations. In the control foals, there was marked individual variation in the increases in equine IgM concentration (range, 5 to 73 mg/dl) after ingestion of colostrum. With the exception of day 49 after foaling, there was no statistical difference between groups for serum IgM concentration after day 3, and both groups had parallel rates of IgM synthesis. Bovine IgM was undetectable at foaling and maximal serum concentration ranged from 200 to 350 mg/dl following ingestion of colostrum. The calculated bovine and equine IgM half-lives were 8 and 5 days, respectively. The coefficients of absorption of bovine IgG and IgM were 30.9 and 84, respectively, in the principal foals. In the control foals, the coefficient of absorption of equine IgG and IgM was 35 and 30, respectively. One principal foal was excluded from the study because it died of aspiration pneumonia at 2 days of age.

Eimeria mitis, 2 strains, chickens, reduced intestinal absorption of glucose and L-methionine, reduced weight gain, depigmentation of plasma, gross lesions absent

Objective-To evaluate effects of age and body size of dogs on intestinal permeability (unmediated diffusion) as measured by the ratio of urinary lactulose to L-rhamnose (L:R) and absorption (carrier-mediated transport) as measured by the ratio of urinary D-xylose to 3-O-methyl-D-glucose (X:MG) and to determine whether these variables correlated with fecal quality. Animals-6 Miniature Poodles, 6 Standard Schnauzers, 6 Giant Schnauzers, and 6 Great Danes. Procedure-A solution that contained lactulose and rhamnose or xylose and 3-O-methyl-D-glucose was administered orally to dogs that were 12, 22, 36, and 60 weeks old. Urine was collected 6 hours later, and urinary L:R and X:MG were calculated. Fecal moisture and scoring were recorded during the same periods. Results-Age and breed did not affect intestinal absorption, and we did not detect a relationship between X:MG and fecal variables. In contrast, we detected significant effects of age and body size on intestinal permeability. Puppies (12 weeks old) and large dogs had higher intestinal permeability than adult (60 weeks old) and small dogs. The increased intestinal permeability in large dogs was associated with lower fecal quality as indicated by the significant positive correlations between L:R and fecal moisture (r, 0.61) and L:R and fecal scores (r, 0.86) in adult dogs. Conclusion and Clinical Relevance-These results indicate that age and body size should be considered when assessing intestinal permeability by use of the L:R urinary excretion test in dogs. High intestinal permeability could be a possible cause of poor fecal quality in large dogs.

In a crossover trial, 7 healthy, 7- to 29-day-old, unweaned Finnish Ayrshire calves were given a single dose of 20 mg of tinidazole/kg of body weight, IV, and a single dose of 25 mg of tinidazole/kg orally. Blood samples were collected serially, and serum concentration of tinidazole was measured by use of high-performance liquid chromatography. Serum concentration vs time data were analyzed by use of the statistical moment theory. Terminal half-life was 394 minutes after IV administration and 524 minutes (harmonic mean) after oral administration. The corresponding system moment mean residence times were 542 +/- 61.8 minutes and 812 +/- 117 minutes (arithmetic mean +/- SD), respectively. Estimated volume of distribution at steady state and total body clearance were 0.74 +/- 0.05 L/kg and 1.37 +/- 0.13 ml/min/kg, respectively. Tinidazole was rapidly and totally absorbed from the gastrointestinal tract. Mean absorption time was 270 +/- 160 minutes, and the observed peak serum concentration was detected at 240 minutes. Bioavailability was 99.5 +/- 3.9%.

The sodium-dependent transporter system responsible for L-glutamine uptake by brush border membrane vesicles prepared from equine jejunum was characterized. Vesicle purity was ascertained by a 14- to 17-fold increase in activity of the brush border enzyme markers. Glutamine uptake was found to occur into an osmotically active space with negligible membrane binding. The sodium-dependent velocity represented approximately 80% of total uptake and demonstrated overshoots. Kinetic studies of sodium-dependent glutamine transport at concentrations between 5 micromolar and 5 mM revealed a single saturable high-affinity carrier with a Michaelis constant of 519 +/- 90 micromolar and a maximal transport velocity of 3.08 +/- 0.97 nmol/mg of protein/10 s. Glutamine uptake was not affected by changes in environmental pH. Lithium could not substitute for sodium as a contransporter ion. 2-Methylaminoisobutyric acid inhibited the sodium-dependent carrier only minimally, but marked inhibition (> 90%) was observed in the presence of histidine, alanine, cysteine, and nonradioactive glutamine. Kinetic analysis of the sodium-independent transporter revealed it to have a Michaelis constant = 260 +/- 47 micromolar and a maximal transport velocity of 0.32 t 0.06 nmol/mg of protein/10 s. We conclude that glutamine transport in equine jejunal brush border membrane vesicles occurs primarily via the system B transporter and, to a lesser extent, by a sodium-independent carrier.

Intestinal permeability was assessed in 12 healthy cats by use of a differential sugar absorption test. A 50-ml isotonic aqueous solution containing a combination of 1.8 g of the disaccharide lactulose and 1.7 g of the monosaccharide mannitol was administered to cats via nasogastric tube. Urine was collected after 6 hours, and all urine samples were analyzed the same day, using a gas-liquid chromatographic technique (GLC) and an enzymatic assay (ENZ). Median urinary recovery of lactulose was 0.27 and 0.54% determined by GLC and ENZ, respectively. Differences between these groups were statistically significant (P = 0.023), and correlation between assays was high (r = 0.94, P < 0.01). Median urinary recovery of mannitol was 1.93 and 2.09% for GLC and ENZ, respectively. There were no statistically significant differences between these groups and the correlation between assays was high (r = 0.85, P < 0.01). The median lactulose-to-mannitol ratio was 0.29, using GLC, and was 0.52, using ENZ. Correlation of these ratios was again high (r = 0.93, P < 0.01).

The possibility that the canine pancreas might have an important role in the physiologic absorption of cobalamin (vitamin B12) has been explored by determining the effect of exocrine pancreatic insufficiency on cobalamin absorption and by examining the subsequent influence of bovine pancreatic enzymes and canine pancreatic juice. Exocrine pancreatic insufficiency was induced by ligation of pancreatic ducts and confirmed by indirect assessment of exocrine pancreatic function. Cobalamin absorption was determined by oral administration of cyano[58Co]cobalamin and quantitation of radioactivity in blood, urine, and feces during 48 hours. Pancreatic duct ligation resulted in a significant (P less than 0.001) decrease in cobalamin absorption, which was not restored by oral administration of bovine pancreatic enzymes, despite considerable improvements in steatorrhea and in vivo proteolytic activities. In marked contrast, malabsorption of cobalamin was significantly (P less than 0.05) reversed by oral administration of canine pancreatic juice. These results indicate that pancreatic secretions have an important role in the normal absorption of cobalamin in the dog, a role that does not appear to be attributable to pancreatic enzymes, but is consistent with the existence of a pancreatic intrinsic factor in this species.