The Mackay-Marg, Tono-Pen, and Challenger applanation tonometers were evaluated in vivo in 12 clinically normal eyes of 6 dogs. Tonometric measures of intraocular pressure (IOP) were compared with closed manometric IOP measurements from the anterior chamber of anesthetized dogs. The tonometers were evaluated at IOP that ranged from 5 to 100 mm of Hg. The Mackay-Marg tonometer was the most reliable instrument when evaluated at IOP from 5 to 100 mm of Hg (r2 = 0.996) and from 10 to 30 mm of Hg (r2 = 0.962). The Tono-Pen tonometer was also reliable (r2 = 0.967) over the range of IOP, but consistently overestimated IOP at lower pressures and underestimated IOP at higher pressures. The Mackay-Marg and Tono-Pen measurements were essentially linear. When evaluated from 10 to 30 mm of Hg, r2 was 0.828 for the Tono-Pen tonometer. The Challenger tonometer, although reliable over the full range of IOP (r2 = 0.965), proved to be less accurate, as indicated by lack of a good linear equation.

Hip dysplasia is an affection of the coxofemoral joint that progresses until stabilization is caused by fibrosis and osteoarthritic changes. This stabilization process can be examined by clinical and radiographic methods. The capability of evaluating the procollagen concentrations in liquids, such as serum and synovial fluid, has further offered the basis for an objective biochemical evaluation of the stabilization process. Our study was performed to evaluate whether determination of procollagen concentrations was suitable for the use in practice. The procollagen type-III aminoterminal peptide (P-III-NP) concentration was measured in serum and in synovial fluid from coxofemoral joints in 20 dogs. Dogs were grouped on the basis of evidence of dysplasia and osteoarthritic changes of the hip: (1) a control group of 6 dogs without clinical or radiographic signs of hip dysplasia, and (2) dysplastic group of 14 dogs, which was further grouped with respect to the coxofemoral joint laxity, as determined by the Ortolani test. Synovial fluid concentration of P-III-NP was significantly (P < 0.05) higher in fluid from dysplastic joints than in fluid from normal joints. Serum concentrations of P-III-NP were significantly (P < 0.05) higher in dogs in which results of the Ortolani test were positive.

Two experiments were conducted to determine changes in body composition and various physiologic variables in feeder pigs under simulated marketing conditions. In the first experiment, pigs were assigned to 1 of 4 treatment groups for 48 hours: (1) no water and feed; (2) water ad libitum, no feed; (3) no water, feed ad libitum; or (4) water and feed ad libitum. During a 48-hour recovery period, all pigs were allowed feed and water ad libitum. Plasma triiodothyronine decreased (P < 0.01) within the first 24 hours in groups-1 and -2 pigs, but increased (P < 0.01) within the first 6 hours of the recovery period. The circadian rhythm of plasma cortisol was disrupted in groups-1 and -3 pigs and during recovery in group-1 pigs. Packed cell volume increased (P < 0.05) in groups-1 and -3 pigs and returned to initial values within the first 24 hours of the recovery period. In the second experiment, body composition was estimated by the 40K technique for fat-free body mass, percentage of nitrogen, and percentage of fat. Body composition was determined before and after pigs were allotted to 1 of 2 groups for 48 hours: group-1 pigs were given feed and water ad libitum and group-2 pigs were not given feed and water. Group-1 pigs gained 2.2 kg of body weight (P < 0.01), 0.6% fat (P < 0.01), 0.7 kg of fat-free body mass, and 0.02% nitrogen (P > 0.01). Group-2 pigs lost 2.3 kg of body weight (P < 0.01), 0.6% fat (P < 0.01), 2.0 kg of fat-free body mass (P < 0.01), and 0% nitrogen.

Ten healthy sedentary Thoroughbreds with previous race training experience were trained conventionally for 9 weeks. Muscle biopsy samples were obtained before and after training and after 6 weeks of detraining pasture rest. Biopsy samples were obtained from the right deltoid, triceps, vastus lateralis, middle gluteal, biceps femoris, and semitendinosus muscles. The deep-frozen biopsy samples were analyzed for activities of succinate dehydrogenase (SDH), 3-hydroxy-acylcoenzyme A dehydrogenase (HAD), and phosphorylase (PHOS) and for glycogen concentration. The triceps and gluteal muscle samples were also serially sectioned and stained for myofibrillar actomyosin adenosine triphosphatase (ATPase) activity after alkaline (pH 10.3) and sequential acidic (pH 4.34) ATPase inactivation. Fiber types I (alkaline preincubation), IIA1, IIA2, and IIA3 (sequential acidic preincubation over 5 minutes) were identified and were evaluated for fiber-type distribution and fiber areas. Increases in response to training were observed in deltoid and vastus muscle SDH and gluteal muscle HAD activities, and deltoid muscle glycogen concentration (P < 0.05 to P < 0.01). Changes in PHOS activity were not observed. Type-IIA1, -IIA2, and -IIA3 fiber areas in triceps muscle were increased in response to training (P < 0.05 to P < 0.01). Changes in fiber-type distribution did not occur in response to training. Changes in muscle enzyme activities, glycogen concentration, fiber types, and fiber areas were not seen from posttraining to detraining. Further increases were observed when detraining values were compared with pretraining values in deltoid, triceps, vastus, gluteal, and biceps femoris muscle SDH activities and in gluteal muscle glycogen concentration (P < 0.05 to P < 0.01). It was concluded that the predominant failure to detect training-induced muscle enzyme changes, along with documentation of increases in fast-twitch muscle fiber areas, indicate that conventional Thoroughbred training is principally of a sprinting nature. A greater emphasis on longer, slow endurance work early in training might add greatly to Thoroughbred horses' abilities to withstand the rigors of sprint training.

Colostrum-deprived lambs and CF1 mice were vaccinated with water-in-oil emulsion vaccines containing nonviable whole cells (WC) of Corynebacterium pseudotuberculosis with and without muramyl dipeptide (MDP). Efficacy of vaccines was determined from the survival of mice and lesions in lambs after IV injection of 10(4) colony-forming units of C pseudotuberculosis. In mice, protection was related to the concentration of WC in the vaccine. At 50, 100, or 150 micrograms of WC, protection was good (78.8%). At 10 or 25 micrograms of WC, protection was considerably less (54.7%). At high WC concentrations, protection could only be moderately increased to 82.3% with high (50 and 100 micrograms) concentrations of MDP or increased to 90% protection with low (5 and 10 micrograms) concentrations of MDP. At low WC concentrations, protection significantly decreased to 32% (P < 0.025) with high concentrations of MDP, but significantly increased to 72.5% (P < 0.025) with low concentrations of MDP. Therefore, the amount of protection with lower concentrations of WC and MDP was comparable with the amount of protection with higher concentrations of WC without MDP. In lambs, high prechallenge antibody titers (geometric mean titers from 5.1 to 5.4 by day 35) were observed after vaccination with WC. Protection and vaccination site abscesses in lambs were related to the concentration of WC and MDP. Pulmonary or vaccination site abscesses were not observed in 4 of 4 lambs vaccinated with 1 mg of WC + 50 micrograms of MDP.

A deterministic mathematical model of the population biology of pseudorabies in swine was used to clarify some of the basic features of the host-virus relationship and to inquire into the circumstances that promote or impede virus persistence in a single herd. When the basic reproductive rate of the infection (ie, the number of secondary infections resulting from the introduction of a single infective animal into a wholly susceptible herd) is greater than unity, the model suggests that the number of infective individuals in the herd will undergo highly damped oscillations to a final equilibrium level. The most important determinants of virus persistence are herd size and the density at which sows are maintained. There is a threshold density of susceptible individuals below which the virus will eventually be eliminated from the herd, even when specific control measures are lacking. Test and removal strategies hasten virus elimination when herd density is already below threshold, but are otherwise likely to succeed only when the removal of latent infections reduces the basic reproductive rate of the infection below unity. Vaccination strategies may also result in virus elimination, but only in relatively small herds.

The cardiopulmonary effects of 4 positions (standing, right lateral, left lateral, and dorsal recumbency) were evaluated in conscious cattle in which no sedatives or anesthetic drugs were given. Each position was maintained for 30 minutes, during which time there were no significant changes in heart rate, respiratory rate, mean arterial blood pressure, arterial pH, PaCO2, arterial base excess, or venous blood gas values. Significant decreases in PaO2 developed when cattle were in lateral positions and dorsal recumbency. Cardiac index was unchanged in all positions, except in dorsal recumbency at 30 minutes, when it was significantly decreased.

Fecal samples were collected from 200 feeder-calves on farms in Tennessee, after assembly at a Tennessee auction market, and after transport to a Texas feedyard. A final fecal sample was collected from each calf after 30 days of feedyard confinement. The fecal samples were cultured for the presence of Salmonella spp. Salmonella isolates were serotyped and antimicrobial drug-resistance patterns determined. The number of calves fecal culture-positive for Salmonella spp increased from 0 on the Tennessee farms and auction market to 3/200 (1.5%) at entry into the Texas feedyard, and 16/200 (8%) after 30 days of feedyard confinement. Salmonella serotypes isolated and the number of isolates of each serotype were S reading (8), S cerro (4), S newbrunswick (3), S anatum (2), and S typhimurium (copenhagen; 2). All Salmonella isolates were resistant to 5 or more of 13 antimicrobial drugs tested. Salmonella reading isolates were resistant to 10 or 11 of 13 antimicrobial drugs. The results indicated that the calves could have been infected with Salmonella spp prior to or during the course of the study, and that marketing stress as they moved from farm through feedyard may have induced fecal excretion of salmonellae. In addition, the pattern of antimicrobial drug resistance in the Salmonella isolates was broad.

The motor-evoked potential can be reliably recorded in anesthetized dogs by use of percutaneous placement of active recording electrodes near the dorsal lamina of the vertebral column. Two types of responses were observed in this study; short (< 5.5 ms at T9-10)- and long (> 5.8 ms at T9-10)-latency waves. Short-latency waves are larger in amplitude and appear with higher stimulus intensities than do long-latency waves. Short-latency waves are conducted at > 80 m/s and may not reflect pyramidal tract activation. The safety of using higher intensity stimuli to generate short-latency waves has not been determined.

Alpha 2-beta 1-glycoprotein may be found free in horse serum or complexed with alpha-1-proteinase inhibitor to form pre-alpha 2-elastase inhibitor. There has been little information published concerning alpha 2-beta 1-glycoprotein and its possible tissue sources in horses. A peroxidase-antiperoxidase technique was used to identify alpha 2-beta 1-glycoprotein in buffy coat and bone marrow neutrophils of healthy horses. Macrophages and neutrophils in bronchoalveolar lavage samples from clinically normal horses and from horses with chronic pulmonary disease also were positive for alpha 2-beta 1-glycoprotein. Alpha 2-beta 1-glycoprotein was identified in some instances in normal equine hepatocytes of formalin-fixed liver sections. In formalin-fixed liver sections from horses with chronic, small-airway disease and chronic bronchointerstitial pneumonia, alpha 2-beta 1-glycoprotein was observed in some airway secretions and in macrophages.