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.

The patency of mammary papillae was reestablished after surgically induced injury. Perforated prosthetic tubes with affixed Dacron tubing or Teflon strips were implanted in 18 abrabed papillae of lactating dairy cows and were secured with sutures. Wound healing was assessed by palpation and visual inspection. All wounds, with one exception, healed by first intention. Machine milking, reinstituted on day 5 after surgery, caused no apparent discomfort. Grossly and histopathologically, all implants stimulated a variable degree of mucosal metaplasia and hyperplasia. Only implants with Teflon strips became anchored by fibrotic invasion. Mastitis, tube migration, and milk fistulas were complications of the procedure.

Ground reaction forces were measured from the hind limbs of 9 dogs before and after stabilization of unilateral cranial cruciate ligament rupture. Before surgery, peak vertical force, associated impulses, and weight distribution were significantly less (multivariate analysis P less than 0.02) in the affected limb, compared with the clinically normal limb. Craniocaudal peak forces and impulses, divided into braking and propulsion, also were significantly less in the affected limb. At a minimum of 7 months after retinacular imbrication, all vertical and craniocaudal measurements in the affected limb were increased significantly. Significant changes were not found in the normal limb. Furthermore, at the postoperative evaluation, there was no significant difference in any measurement between the affected and normal hind limbs. The results indicated restoration of function in the cruciate-deficient limb when compared with the clinically normal hind limb at a walking gait during the study time period.

First-litter commerical cross-bred gilts were treated with levamisole (1.5, 2.5, or 3.5 mg/kg of body weight) weekly during the last 4 weeks of gestation, because similar treatment of dairy heifers had improved postpartum maternal health and neonatal survival. In the gilts, differences in reproductive performance were not found on the basis of pig survival at birth, pig survival at weaning, birth weight, or weaning weight. Also differences between treated and control gilts were not found in response of circulating lymphocytes to mitogen stimulation (phytohemagglutinin A, concanavalin A, and pokeweed mitogen). In all gilts, the lymphocyte response to mitogen stimulation was decreased during the first week after farrowing.

To study communications and boundaries of the middle carpal and carpometacarpal joints of the horse, 50 forelimbs were obtained from fresh cadaver specimens. Blue latex solution (20 +/- 2.5 ml) was injected into the middle carpal joint, and the specimens were frozen in extension. Frozen specimens were cut into 1-cm sagittal sections from the middle of the radius to the middle of the metacarpus. The communications between the middle carpal and carpometacarpal joints and the presence, length, and position of the distopalmar outpouchings of the carpometacarpal joint were recorded. The middle carpal and carpometacarpal joints always communicated between os carpale III (C3) and os carpale IV (C4). An additional communication between the joints existed in 17 (34%) of the specimens, 10 on the palmar aspect of C4, and 3 on the palmar aspect of os carpale II (C2). When os carpale 1 (C1) was present (n = 5), communication between C1 and C2 was observed in 4 of the 5 specimens. In all specimens, medial and lateral distopalmar outpouchings of the carpometacarpal joint were observed and were located between the axial surface of os metacarpale II (MC2) and os metacarpale IV (MC4) and the abaxial surface of the suspensory ligament. There was no significant difference between the lengths of the lateral (2.3 +/- 0.54 cm) or medial (2.6 +/- 0.75 cm) distopalmar outpouchings. Small extensions from the distopalmar outpouchings were seen and extended axially into the fibers of the suspensory ligament or between the suspensory ligament and the distal accessory ligament of the deep digital flexor tendon. In one carpus, the middle carpal joint communicated with the antebrachiocarpal joint between the articulation of the os carpi intermedium (Ci) and the os carpi ulnare (Cu).

The efficacy of febantel paste formulation (6 and 12 mg/kg) against natural infections of gastrointestinal helminths in lambs (n = 33) in Kentucky was evaluated in a controlled test. For the test, 23 lambs were treated orally (17 at 6 mg/kg and 6 at 12 mg/kg) and 10 lambs were not treated. Removals at both dosages in treated lambs were 95% to 100% for species of immature and mature Haemonchus, Trichostrongylus, and Cooperia; and mature Ostertagia females, Nematodirus, and Strongyloides. For immature Nematodirus, removals were 92% and 77% at the dosages of 6 and 12 mg/kg, respectively. Only a few specimens (av less than 100) of some other species or stages were found in the nontreated group and removal of them (at both dosages) were 94% to 100% for Ostertagia (immature and males), Strongyloides (immature), Oesophagostomum (immature), and Monieiza (mature); and 61% (at 6 mg/kg) and 100% (at 12 mg/kg) for Capillaria (mature), 0% for Trichuris (mature, at both dosages), and 67% (at 6 mg/kg) and 100% (at 12 mg/kg) for Oesophagostomum (mature).

Morphologic changes developing during bovine mammary involution were examined. Quarter biopsy specimens were obtained weekly from 5 cows beginning the day milking was discontinued through parturition. Light and electron microscopic examination of mammary tissue indicated a gradual reduction in synthetic and secretory activity of alveolar epithelium as involution progressed. Light microscopic morphologic analysis revealed increases in stroma and nonactive secretory epithelium, with concomitant decreases in epithelium, lumen, and fully active secretory epithelium during the first 2 weeks of involution. Electron microscopic analysis of alveolar epithelium revealed decreased number of organelles associated with milk synthesis and secretion during this time. These changes reversed gradually beginning 2 weeks before parturition, and by the time of calving, cell structure was typical of lactating glands. Tissue from infected quarters had less synthetic and secretory ability as indicated by significantly higher percentages of stroma and nonactive cells, but lower percentages of lumen and moderately active cells, compared with uninfected quarters. Infected quarters also had more leukocytes infiltrating the epithelium, lumen, and stroma, compared with uninfected quarters. Microscopic examination of macrophages and neutrophils suggested these cells removed milk components and cellular debris during involution. Large numbers of plasma cells, with distended cisternae of rough endoplasmic reticulum, suggested local antibody production during the periparturient period.

In a case-control study of risk factors associated with an episode of nosocomial Salmonella krefeld infection in dogs at the veterinary medical teaching hospital, data on 20 case dogs and 75 control dogs were obtained by review of hospital records. Univariate and multivariate statistical analyses were carried out for possible risk factors for infection to obtain odds of Salmonella krefeld isolation, given exposure to each risk factor of interest. Compared with control dogs, case dogs were 11.9 times more likely to have been fed rice, 7 times more likely to have had radiography done, 10.2 times more likely to have been a resident in ward 2, 5.6 times more likely to have been given antimicrobial agents orally, 11.3 times more likely to have been given antimicrobial agents parenterally, and 37.9 times more likely to have been given antimicrobial agents orally and parenterally (P less than 0.05).

An index was developed to measure the proportion of intramammary infections caused by environmental microorganisms on dairy farms. This environmental index can be interpreted as the probability that an intramammary infection was caused by an environmental pathogen, rather than by a contagious pathogen. Using the environmental index as the outcome variable, risk factors for environmental mastitis were studied on 10 dairy farms in New York. Turning the cows outside was associated with lower environmental index, and having cows drink from a stream increased the environmental index. Selective (rather than uniform) nonlactating cow intramammary treatment was related to a lower environmental index (apparently because the farms practicing selective nonlactating cow treatment suffered from epizootics of contagious mastitis).