Peanut agglutinin (PNA) and surface immunoglobulin (SIg) were investigated as markers for T and B lymphocytes in blood and lymphoid tissues of dogs of various ages. In the blood study, 4 age groups (n = 8 dogs/group) were used. The mean (+/- SD) percentages of PNA-positive (PNA +) cells were 68.4 +/- 8.6% (group 1, < 1 year old), 70.3 +/- 9.2% (group 2, 1 to 2 years old), 72.0 +/- 3.7% (group 3, 5 to 6 years old), and 63.8 +/- 10.1% (group 4, 10 to 11 years old). The mean percentages of SIg-positive (SIg+) cells in blood were 32.1 +/- 10.6% (group 1), 43.2 +/- 7.0% (group 2), 34.3 +/- 4.8% (group 3), and 35.0 +/- 6.8% (group 4). The mean total percentages of PNA+ and SIg+ cells were 100 +/-6% (group 1), 113.5 +/- 4.9% (group 2), 106.3 +/- 5.3% (group 3), and 98.9 +/- 9.2% (group 4). The proportions of PNA+ and SIg+ cells in dogs of group 2 were significantly (P < 0.05) different from those in dogs of the other groups. Serial changes in PNA+ and SIg+ cells were investigated in blood of 6- to 29-week-old pups (n = 8). A significant (P < 0.05) transient decrease in PNA+ cells and a corresponding increase in SIg+ cells was observed in pups between 14 and 17 weeks old. Lymphoid tissue specimens and blood samples were obtained from 2- to 6-month-old dogs (n = 11) and from 6- to 12-month-old dogs (n = 10). Percentages reflected the combined data from both groups because there were no significant differences between the 2 age groups. The mean percentages of PNA+ cells were: blood, 68.4 +/- 8.6%; thymus, 86.6 +/- 16.3%; spleen, 29.5 +/-16.0%; lymph node, 48.5 +/- 16.0%; and bone marrow, 30.8 +/- 26.4%. The mean percentage of SIg+ cells were: blood, 32.1 +/- 10.6%; thymus, 3.1 +/- 5.5%; spleen, 69.3 +/-10.3%; lymph node, 55.4 +/- 15.2%; and bone marrow, 65.4 +/- 22.4%. The procedure to identify T lymphocytes in blood and lymphoid tissue was easy to perform, was reproducible, and could be performed on as few as 10(6) cells.

Each of twenty blood samples taken from apparently healthy Korean cows was used to produce five different mixtures of autologous plasma and blood corpuscles such that their values of packed cell volume(PCV) lay between 10 to 50ml/100ml. The measurement of erythrocyte sedimentation rate(ESR) using 45 degree-angled Wintrobe hematocrit tube, 3mm bore, (45deg C-Wintrobe-ESR) was practised for the blood of various levels of PCV lowered. Correlation of the ESR to PCV showed curvilinear regression each in three levels of PCV under the ambient temperature of 10deg C, 20deg C and 30deg C. Correlation of the ESR to the ambient temperature showed linear regression each in five levels of PCV. The ESR increased with ascending ambient temperature, and magnitude of the increase of the ESR became greater as the level of PCV lowered. Correlation of the ESR to PCV showed curvilinear regression each in three levels of the ambient temperature, and the ESR was increased with decreasing PCV. The data were statistically analysed and a list of relative anticipated 45deg C-Wintrobe-ESR values for PCV and ambient temperature was presented.

Three Beagles with chronic anemia and reticulocytosis were studied. The dogs originated from a large breeding colony and appeared clinically normal with the exception of splenomegaly. The PCV ranged from 30 to 39% (normal, 46 to 56%), with reticulocyte indices of 2.3 to 9.9. Red blood cells were morphologically normal, and examination of marrow aspirates revealed erythroid hyperplasia. Shortened chromium-51 RBC life-spans (7.2 to 15.4 days in anemic dogs; 22.2 to 25.2 days in control dogs) documented a hemolytic anemia. Acquired causes of hemolytic anemia were ruled out. Red blood cells had normal glycolytic enzyme activities, no evidence of unstable or abnormal hemoglobin, and had altered osmotic fragility curves. The breeding of 2 anemic dogs resulted in off-spring with anemia and reticulocytosis. Polyacrylamide gel electrophoresis revealed no abnormalities in RBC membrane cytoskeletal proteins in all anemic adult dogs and in 3 offspring.

Chloramphenicol was administered by constant IV infusion to 7 healthy postpartum cows at rates predicted to approach a steady-state plasma concentration of 5 micrograms/ml. After 8 hours of constant IV infusion, uterine tissues were removed surgically and were assayed for chloramphenicol concentrations. Mean plasma-to-tissue ratios of chloramphenicol concentrations were 3.05, 3.63 (6 cows only), and 3.22 for caruncles, endometrium, and uterine wall, respectively. Plasma-to-tissue ratios of the 3 tissues were not significantly different (P greater than 0.10). Intrauterine (IU) injections of chloramphenicol (20 mg/kg of body weight) were administered to 3 healthy postpartum cows. The mean value of the fraction of the drugabsorbed from the uteri of these cows was 0.04. Mean concentrations of chloramphenicol were 43.8 micrograms/g in caruncles, 34.6 micrograms/g in endometrium, 2.8 micrograms/g in uterine wall, and 2.9 micrograms/ml in plasma 8 hours after IU injections. Chloramphenicol has now been banned for use in food-producing animals in the United States because of its potential for causing toxicosis in human beings. It is illegal to use chloramphenicol in food-producing animals in the United States and in some other countries as well. This includes use by the IU route of administration because chloramphenicol and most drugs are absorbed from the uterus into the bloodstream and are distributed to milk and tissues.

A commerical radioimmunoassay kit designed for measuring gastrin in human serum was validated for use with equine serum. This nonextraction, double-antibody procedure uses an antiserum with broad specificity for molecular forms of gastrin. Synthetic human gastrin (G17-I) was added to pooled equine serum, and the observed assay values were compared with the mass added. Recovery was 99 to 115% in the gastrin concentration range of 40 to 640 pg/ml. Dilutions of postprandial serum with serum from fasted horses were assayed, and the inhibition curves were compared with those of the human gastrin kit standards, using a log-logit transformation. The slopes of the sample dilution plots were not significantly different from the slopes ofthe standard curves. Ethylenediamine tetraacetate and heparin adversely affected the assay, resulting in lower assayed gastrin concentration values. The intra-assay coefficient of variation (n = 10) was 3.8%, and the interassay coefficient of variation (n = 6) was 11.2%. The assay sensitivity, as reported by the manufacturer, is 8 pg/ml. Gastrin concentrations in serum from fasted horses ranged from undetectable values (less than 8 pg/ml) to 17.5 pg/ml, and peaked at a mean value (n = 6) of 70 pg/ml 3 hours after feeding. Serum cortisol values monitored during the postprandial blood collection period were in the normal range for horses.

Parasite-free, 4-month-old-calves were inoculated with Ostertagia ostertagi and/or Trichostrongylus axei, followed 6 weeks later by inoculation with increasing doses of O ostertagi for 8 weeks in the 2 groups (n = 9) of calves that had been given O ostertagi. Gastrin immunoreactivity concentration in serum was measured before and after infection and was correlated with changes in mucosal thickness. Gastrin immunoreactivity concentration in preinoculation control sera ranged from 95.2 to 287.1 pg/ml, and increased values were measured in all parasitized calves after 15 weeks. Significantly (P < 0.05) increased serum gastrin immunoreactivity concentration compared with the preinfection value, was found in calves infected with O ostertagi or T axei, and highly significant (P < 0.01) values were observed in calves infected with both parasites. Abomasal mucosal hyperplasia was observed in all parasitized calves; increased mucosal thickness and mucosal cross-sectional area were most prominent in calves infected with O ostertagi and T axei.

Amendments to the Animal Welfare Act (PL 99-198) require that an exercise program for dogs be established by the attending veterinarian. A 6-week study was conducted to determine the effects of a moderate exercise program in purpose-bred Beagles. Sixteen male Beagles (4/group) were maintained as follows: (1) standard cage without exercise; (2) standard cage with individual exercise periods (35 minutes, 3 times/week); (3) large cage without exercise; and (4) standard cage with group-release exercise periods. Blood samples were collected for CBC, serum biochemical analysis including determination of serum cortisol concentration, and immune function (lymphocyte transformation assay). Group-released dogs interacted with each other during most of the exercise time. Fighting in these dogs occurred only during the third week. Dogs had little inclination to exercise when released along into the exercise area. Regardless of the size of the cage, dogs did not exercise unless human beings were present in the room. There were no significant differences in laboratory findings among dogs in the 4 groups. This moderate exercise program had no demonstrable effects. Similarly, continuous cage housing, without a formal exercise program, could not be determined to be detrimental to the physiologic or health status of dogs.

The tarsocrural joints of 11 horses were inoculated with 1.2 to 2.16 x 10(6) viable Staphylococcus aureus organisms susceptible to a trimethoprim-sulfadiazine (TMP-SDZ) combination with minimal inhibitory concentration (MIC) of 0.25 microgram of TMP/ml and 4.75 microgram of SDZ/ml. Antimicrobial treatment consisted of oral administration of a TMP-SDZ combination-30 mg/kg of body weight given once daily (group-1 horses) or 60 mg/kg given as 30 mg/kg every 12 hours (group-2 horses). Paired serum and synovial fluid samples were obtained before intra-articular inoculation with the S aureus, after inoculation with S aureus but before antimicrobial treatment, and after inoculation at various hourly intervals after oral administration of the TMP-SDZ combination. The TMP-SDZ combination was administered daily in the 2 dosages for 21 days. Samples were collected after day 3 of repetitive drug administration so that drug steady-state concentration would have been achieved. Serum and synovial fluid samples were analyzed for TMP and SDZ concentrations. Administration of the TMP-SDZ combination at a dosage of 30 mg/kg once daily was not effective in maintaining TMP or SDZ concentrations above the MIC of TMP-SDZ for the S aureus (0.25 and 4.75 microgram/ml for TMP and SDZ, respectively) in the infected synovial fluid or in maintaining adequate TMP concentration in the serum. The alternative use of the TMP-SDZ combination at a dosage of 60 mg/kg given as 30 mg/kg every 12 hours was effective in maintaining serum and synovial fluid concentrations of TMP and SDZ that were greater than the MIC for the infective organism. Sulfadiazine concentration was significantly (P less than or equal to 0.05) lower in the infected synovial fluid sample than that in the corresponding serum sample. We concluded that administration of 60 mg of TMP-SDZ/kg given as 30 mg/kg every 12 hours is more effective than 30 mg/kg given once daily for the treatment of equine infectious arthritis caused by organisms for which the MIC of TMP-SDZ is less than or equal to 0.25-4.75 microgram/ml.

Concentrations of serum thyroxine (T4) and 3,5,3'-triiodothyronine (T3) were determined after the administration of freshly reconstituted thyrotropin-releasing hormone (TRH), reconstituted TRH that had been previously frozen, or thyrotropin (TSH) to 10 mature dogs (6 Greyhounds and 4 mixed-breed dogs). Thyrotropin-releasing hormone (0.1 mg/kg) or TSH (5 U/dog) was administered IV; venous blood samples were collected before and 6 hours after administration of TRH or TSH. Concentrations of the T4 and T3 were similar (P > 0.05) in serum after administration of freshly reconstituted or previously frozen TRH, indicating that TRH can be frozen at -20 C for at least 1 week without a loss in potency. Concentrations of T4, but not T3, were higher after the administration of TSH than they were after the administration of TRH (P < 0.01). Concentrations of T4 increased at least 3-fold in all 10 dogs given TSH, whereas a 3-fold increase occurred in 7 of 10 dogs given freshly reconstituted or previously frozen TRH. Concentrations of T4 did not double in 1 dog given freshly reconstituted TRH and in 1 dog given previously frozen TRH. Concentrations of T3 doubled in 5 of 10, 2 of 10, and 5 of 10 dogs given TSH, freshly reconstituted TRH, or previously frozen TRH, respectively. Results suggested that concentrations of serum T4 are higher 6 hours after the administration of TSH than after administration of TRH, using dosage regimens of 5 U of TSH/dog or 0.1 mg of TRH/kg. Additionally, results suggested that Greyhounds have lower concentrations of serum T4 than do mixed-breed dogs, but Greyhounds tend to have higher concentrations of serum T3.