bluuebunny/crossref_metadata_2025 huggingface dataset:
Bluetongue and epizootic hemorrhagic disease in ruminants in Georgia: Survey by serotest and virologie isolation
Authors: Odiawa Godfrey , Blue J. L. , Tyler D. E. , Shotts Ε. B.
Published: February 2025

The frequencies of precipitating antibodies to bluetongue virus (btv) and epizootic hemorrhagic disease virus (ehdv) in domestic ruminants and white-tailed deer (wtd) in Georgia were 36% and 32%, respectively (n = 2,200). The frequencies of seropositivity to btv and ehdv were high among cattle (47% and 42%, respectively [n = 1,068]) and less so in wtd (36% and 34% [n = 414]). The frequencies among sheep were 34% for btv and 29% for ehdv (n = 286), whereas among goats, seropositivity was 8% for btv and 7% for ehdv (n = 433). Serum samples from northeastern Georgia (1 of the 4 regions in the survey) had the highest frequency of precipitating antibodies for btv (45%) and ehdv (38%). The lowest frequency was in southeastern Georgia, with 29% seropositivity for btv and 24% seropositivity for ehdv. Of the 175 farms or herds in the serosurvey, 70% included animals that had btv-precipitating antibodies, and 67% included animals which had ehdv-precipitating antibodies.

Seventeen viral isolates were obtained from individual animals on 9 different farms. Fifteen of the isolates were btv—8 from cattle, 4 from sheep, and 3 from wtd; 8 of them were serotype 11, and 7 were serotype 17. Viral isolates from each of 2 wtd were identified as ehdv serotype 1 and serotype 2. Of the total 17 isolates, 11 were from clinically healthy ruminants, and 6 were from animals with clinical signs of bt or ehd. Five of the viral isolates originated from northeastern Georgia, 7 from the northwestern region, and 5 from the southwestern region; none was obtained from specimens from the southeastern region.
Clavulanic acid-potentiated activity of amoxicillin against Bacteroides fragilis
Authors: Indiveri Mary C. , Hirsh Dwight C.
Published: February 2025

Seventy-seven clinical isolates of Bacteroides fragilis from animal sources were examined for β-lactamase production and resistance to amoxicillin. Sixty-five (84%) of the isolates produced detectable amounts of β-lactamase. Concentrations of amoxicillin > 8 µg/ml were required to inhibit all but 13 (17%) of the isolates evaluated.

Clavulanic acid, a β-lactamase inhibitor, minimally inhibited growth of B fragilis when used alone. However, a synergistic effect was found when amoxicillin and clavulanic acid were used together against B fragilis. Ninety-nine percent of the isolates were inhibited by concentrations of 1 µg of amoxicillin/ml in combination with 0.5 µg of clavulanic acid/ml.
Mononuclear phagocytes of transport-stressed horses with viral respiratory tract infection
Authors: Anderson N. V. , DeBowes R. M. , Nyrop K. A. , Dayton A. D.
Published: February 2025

Twelve horses comprised 3 treatment groups; all horses in 2 of the groups had recently been transported and had clinical and laboratory evidence of respiratory tract infection, with equine influenza type 2 virus being the principal pathogen. Mononuclear phagocytes and other leukocytes from blood, lung, and peritoneal cavity were studied in phagocytosis and erythrocyte-antibody (ea) rosette assays. Total numbers of pulmonary alveolar macrophages were increased over control values in bronchoalveolar lavage (bal) fluid of group 3 horses after recovery from influenza (P < 0.02), whereas the increase in neutrophils in the fluid of those horses approached significance. Lymphocytes in bal fluid of group 3 horses (after recovery from influenza) were in larger proportion than those in fluid of group 1 horses during acute influenza (P < 0.05). Pulmonary alveolar macrophages of group 1 horses formed a lower percentage of ea rosettes than did those of controls (P < 0.01) or group 3 horses (P < 0.02). The differential counts of peritoneal macrophages and neutrophils in horses of groups 1 and 3 were virtually identical at the first collection, but differed from controls at the second collection 4 weeks later; peritoneal macrophages were reduced (P < 0.01), whereas peritonea! neutrophils were increased (P < 0.01). Peritoneal macrophages and peritoneal neutrophils of horses with acute influenza were phagocytic in larger proportion than were those in controls at both collection times (P < 0.01 and P < 0.01 for peritoneal macrophages, and P < 0.01 and P < 0.05 for peritoneal neutrophils, respectively), Peritoneal macrophages displayed immunoglobulin G receptors (ea rosettes), but did not differ in proportion between groups.
Serologic response and lesions in goats experimentally infected with Corynebacterium pseudotuberculosis of caprine and equine origins
Authors: Brown Corrie C. , Olander Harvey J. , Biberstein Ernst L. , Moreno Deborah
Published: February 2025

Fifteen goat kids were experimentally inoculated with Corynebacterium pseudotuberculosis. Five were given a strain of caprine origin (nitrate-negative biotype) intradermally, 5 were given a strain of equine origin (nitrate-positive biotype) intradermally, and 5 were inoculated intranasally with the caprine-origin strain. Animals were monitored for 127 days. The goats given the inocula intradermally developed abscesses; those given caprine-origin strain had multiple lesions both peripherally and in visceral locations (primarily endothoracic abscesses), whereas those given the equine-origin strain had abscesses only at injection sites and draining nodes. The difference in extent of lesions could be due to biotypic bacterial differences or to the individual strains used. Intranasally inoculated goats did not develop abscesses and were essentially no different from controls. The cranial part of the respiratory tract may not be an important portal of entry for C pseudotuberculosis.

Serum samples obtained monthly from all animals were subjected to the synergistic hemolysis-inhibition test, which measures antibodies to the exotoxin of C pseudotuberculosis. Animals with abscesses developed titers within 1 month of inoculation. Animals without abscesses remained seronegative. The synergistic hemolysis-inhibition test may be a reliable diagnostic assay for caseous lymphadenitis in goats.
Thermography of the bovine scrotum
Authors: Purohit Ram C. , Hudson Robert S. , Riddell M. Gatz , Carson Robert L. , Wolfe Dwight F. , Walker Donald F.
Published: February 2025

Thermographic patterns of the bovine scrotum were established in 15 clinically normal bulls and were compared with patterns in 10 bulls with scrotal and testicular diseases. Thermography of a normal scrotum was characterized by a symmetrical and constant thermal pattern with a temperature gradient of 4° to 6° (C) from the base to the apex of the scrotum. There was a significant difference (P < 0.05) in the temperature from the base to the apex of the scrotum (34.94 ± 0.60 C to 30.11 ± 0.91 C).

Lack of thermal symmetry was seen in bulls with unilateral lesions. Inflammation of one testicle increased ipsilateral scrotal infrared emission temperature 2.5° to 3° (C) above that in the contralateral side. If both testes were inflamed and hypermic, there was an overall increase in scrotal temperature of at least 3° (C), and a reduction in temperature gradient of 2 to 3° (C) from the base to the apex of the scrotum. Area temperatures in bulls with chronic testicular degeneration with fibrosis were reduced.
Changes in leukocyte populations in pulmonary lavage fluids of calves after inhalation of Pasteurella haemolytica
Authors: Walker R. D. , Hopkins F. M. , Schultz T. W. , McCracken M. D. , Moore R. N.
Published: February 2025

The distribution of leukocytes in bovine bronchoalveolar lavage fluids was determined in 15 calves at various times after aerosol exposure to Pasteurella haemolytica. For comparison, 10 calves were exposed to aerosols of phosphate-buffered saline solution; 15 calves, to Staphylococcus epidermidis; and 10 calves, to Salmonella typhimurium endotoxin. At 10 minutes after inhalation exposure for each group, the predominant cell type was the macrophage. Macrophages remained the predominant cell type throughout each lavage interval for calves exposed to phosphate-buffered saline solution and Staph epidermidis. For calves exposed to P haemolytica, there was a decrease in the percentage of macrophages detectable by 30 minutes after exposure, with a corresponding increase in the percentage of neutrophils. Sixty minutes after the inhalation exposure to P haemolytica, the percentages of macrophages and neutrophils in the lavage fluid were equal. By 240 minutes after exposure to P haemolytica, > 90% of the cells in the lavage fluids was neutrophils. The increase in the percentage of neutrophils in lavage fluids from calves exposed to S typhimurium endotoxin was similar to that seen for the calves exposed to P haemolytica.
Efficacy of morantel against nematode populations in calves exposed on a pasture stocked for two years with morantel sustained-release bolus-treated calves
Authors: Newby T. J. , Yazwinski T. A. , Presson B. L. , Greenway T. E. , Holtzen H. M. , Bischoff M. J. , Featherstone H. E.
Published: February 2025

Two groups of 10 parasite-free calves were maintained either for 2 weeks on a pasture grazed by nonmedicated cattle (pasture A) or for 3 weeks on a pasture grazed by morantel sustained-release bolus-treated cattle (pasture B) for the preceding 2 years. After a 4-week holding period to allow for maturation of acquired gastrointestinal nematodes, 5 calves from each group were administered a therapeutic dose (10 mg/kg of body weight) of morantel tartrate. All calves were necropsied 1 week later, and the abomasal and small intestinal nematodes were isolated, identified, and enumerated. A comparison of efficacies between nonmedicated and morantel tartrate-treated calves of each pasture demonstrated that morantel was equally effective against the gastrointestinal nematode infections, regardless of infection source (ie, pasture A vs pasture B). The overall nematode reductions due to morantel tartrate treatment of calves that grazed pastures A and B were 98% and 96%, respectively. It was concluded that the sensitivity of gastrointestinal nematodes to morantel tartrate was not diminished in calves maintained on pasture B, which had been stocked with morantel sustained-release bolus-treated calves for the preceding 2 grazing seasons.
Effect of ionophore antibiotics on experimentally induced lactic acidosis in cattle
Authors: Nagaraja T. G. , Avery T. B. , Galitzer S. J. , Harmon D. L.
Published: February 2025

Salinomycin, a new ionophore antibiotic, was tested and compared with lasalocid and monensin for preventing experimentally induced lactic acidosis. Five rumen-fistulated adult cattle were used in a 5 × 5 Latin square design, and the treatments were as follows: no treatment (control), 0.11 mg of salinomycin/kg of body weight (S1), 0.22 mg of salinomycin/kg (S2), 0.66 of lasalocid/kg, and 0.66 mg of monensin/kg. Acidosis was induced by intraruminal administration of a ground corn-corn starch mixture (50:50, 12.5 g/kg) once a day for up to 4 days. Antibiotics were administered along with grain-starch mixture. Rumen and blood samples were obtained before and at 6, 12, and 24 hours after each carbohydrate-antibiotic dosing to monitor acid-base status. Control and S1-treated cattle became ruminally acidotic within 54 hours, whereas cattle treated with S2, lasalocid-. and monensin resisted acidosis for up to 78 hours after dosing. Cattle treated with S2, lasalocid, or monensin had higher rumen pH and lower l( + ) - and d(-)-lactate concentrations than did control or S1-treated cattle. Rumen pH decrease to below 5.0 in S2-, lasalocid-, and monensin-treated cattle was not due to lactic acid, but to increased production of volatile fatty acids. Rumen propionate proportion increased initially in antibiotic-treated cattle, but after 48 hours, butyrate proportion increased significantly. Despite low rumen pH and high lactate concentration, lacticacidemia was not evident, and the systemic acid-base disturbance was mild in control cattle, Blood pH, bicarbonate, and base excess values were higher in S2-, lasalocid-, and monensin-treated cattle than in the control cattle. Hemoconcentration was evident in all cattle. Both control and antibiotic-treated cattle had significant decreases in serum urea nitrogen and potassium concentrations.
Antitrypsin and N-acetyl-β-D-glucosaminidase as markers of mastitis in a herd of Ayshire cows
Authors: Mattila T. , Sandholm M.
Published: February 2025

Microplate analyzers for N-acetyl-β-d-glucosaminidase (NAGase) and antitrypsin in milk were high-capacity systems for determination of subclinical mastitis on a mammary-quarter basis in a herd of 80 Ayshire cows. Infected quarters could be better differentiated from non-infected quarters by interquarter evaluation of milk NAGase and antitrypsin, than by adaptation of threshold values based on measured NAGase and antitrypsin values. This differentiation between healthy quarters and mastitic quarters was further improved by using absolute values and interquarter evaluations in combination. Therefore, quarter-based sample collection in combination with microplate technology and computerization is proposed as the method of choice for monitoring udder health in herds.
Pharmacokinetics of gentamicin in the calf: Developmental changes
Authors: Clarke Cyril R. , Short Charles R. , Hsu Ruei-Ching , Baggot J. Desmond
Published: February 2025

The purpose of this study was to determine the pharmacokinetic values for gentamicin in neonatal calves and to compare these values with those in adult cattle (cows). Gentamicin (4 mg/kg of body weight) was administered iv to 7 Holstein bull calves on days 1 (between 12 and 24 hours of age), 5, 10, and 15 after birth, and was administered once iv to 7 Holstein cows. Serum was collected from each animal before administration and at 22 different time intervals from 2 to 400 minutes after injection. Sera were analyzed for gentamicin concentrations. Decay of serum gentamicin concentrations was best described by a 2-compartment pharmacokinetic model. Elimination half-life (t½(β)) of gentamicin decreased from day 1 (149 minutes) to day 5 (119 minutes), but did not change between days 5 and 15 (111 minutes). Compared with the t½(β) in 1- and 15-day-old calves, the t½(β) in cows was shorter (76 minutes). In the calves, apparent volume of distribution (based on total area under the disposition curve) did not change between 1 (393 ml/kg) and 5 (413 ml/kg) days of age, decreased on day 10 (341 ml/kg) and cows day 15 (334 ml/kg), and was markedly smaller than that in cows (140 ml/kg). Total body clearance of gentamicin in cows (1.29 ml/min·kg) was lower than that seen in calves on day 1 (1.92 ml/min·kg) and on day 15 (2.10 ml/min·kg). The decrease in apparent volume of distribution of gentamicin was mirrored by a large decrease in the extracellular fluid volume, as measured by inulin space. Age-related changes in total body water were not found, as measured by antipyrine space. The percentage protein binding of gentamicin was < 30%.
Oxytetracycline concentrations in plasma and lung of healthy and pneumonic calves, using two oxytetracycline preparations
Authors: Ames T. R. , Patterson E. B.
Published: February 2025

Drug concentrations in lung tissue and plasma pharmacokinetics of a long-acting preparation of oxytetracycline were compared with those of a standard preparation of oxytetracycline given to healthy and pneumonic calves. Both preparations achieved higher concentrations in the pneumonic lung when compared with those in the normal-appearing lung of the same group. A difference in concentrations in lung tissue was not found between preparations at either 24 or 48 hours. The plasma pharmacokinetic values did differ between preparations. Comparatively, the long-acting oxytetracycline had a smaller rate constant for disposition, a larger volume of distribution divided by bioavailability constant, and a longer half-life. A difference in pharmacokinetic values was not observed between healthy and pneumonic calves.
Neostigmine methylsulfate delays gastric emptying of particulate markers in horses
Authors: Adams Stephen B. , MacHarg Margaret A.
Published: February 2025

Eight horses were allotted to 2 groups, each of 4 horses. All horses were given 100 plastic markers intragastrically via a nasogastric tube. One group of animals (control group) was not given medication after marker administration. The other group (test group) was given neostigmine methylsulfate (0.022 mg/kg of body weight) in the subcutaneous tissue at the time of marker administration and 30, 60, and 90 minutes later. All horses were killed 135 minutes after marker administration to locate the beads in the gastrointestinal tract. Gastric emptying of the markers was significantly delayed (P < 0.05) in horses given neostigmine methylsulfate.
Experimental infection of lactating goats with Leptospira interrogans serovars pomona and hardjo
Authors: Tripathy D. N. , Hanson L. E. , Mansfield M. E. , Thilsted J. P.
Published: February 2025

Pathogenesis of Leptospira interrogans serovars pomona and hardjo was evaluated in 14 lactating goats. Although mild clinical signs of leptospiral infection characterized by pyrexia and reduction in milk yield appeared in some animals, a consistent clinical pattern was not observed in the inoculated animals. The pomona serovar was isolated from the kidney of 1 of the 4 goats inoculated with serovar pomona. The hardjo serovar (strain UI 750) was isolated in the rabbit serum-supplemented bovine albumin polysorbate-80 liquid medium only from the mammary gland of 1 of 4 goats at 13 days after inoculation with serovar hardjo. The positive culture was detected after an 8-month incubation period.
Effect of skin graft preparation and graft survival on the secondary contraction of full-thickness skin grafts in dogs
Authors: Pope Eric R.
Published: February 2025

The effects of 4 skin grafting techniques and graft survival on the secondary contraction of full-thickness skin grafts were evaluated. A total of 48 skin grafts were done on 12 dogs, with 2 skin grafts placed on both sides of the thorax of each dog. The grafting techniques included the sheet graft, sheet graft with continuous low-level suction provided by a butterfly catheter and evacuated glass tube, pie-crust graft, and nonexpanded mesh graft. Graft viability was assessed by visual inspection 10 days after surgical operation. Thirty skin grafts (64%) had a viability of 90% or greater. The final area of these grafts ranged from 73% to 119% of the original area.

The secondary graft contraction followed a similar pattern for all graft types. During the first 10 days after surgical operation, the grafts contracted to 83% of their original area. Enlargement of the grafts began between 10 and 21 days after surgical operation. By 12 weeks, the grafts had attained a mean value of 96% of the original area. A significant difference in final area was not observed among graft types. Grafts with a high percentage of viability generally contracted less than those with larger areas of necrosis, but statistical relationship between viability and degree of contraction could not be proven. The results of the present study indicate that full-thickness skin grafts may be successfully done in dogs and that the grafts can be expected to undergo minimal postoperative contraction when graft survival is nearly complete.
Deposition of fibronectin in articular cartilage of canine osteoarthritic joints
Authors: Burton-Wurster N. , Lust G.
Published: February 2025

Deposition of fibronectin was examined in articular cartilage of healthy and osteoarthritic joints of Labrador Retriever dogs. Abnormal cartilage from osteoarthritic joints contained up to 20 times more fibronectin than did disease-free cartilage. Compared with normal cartilage, the rate of fibronectin synthesis in osteoarthritic cartilage was increased and a greater proportion of the newly made fibronectin accumulated in the lesion cartilage matrix. The rate of release of endogenous prelabeled [3H]fibronectin from disease-free expiants was similar to the rate of release from degenerated cartilage expiants into incubation media. Concentrations of fibronectin were greater in synovial fluid from osteoarthritic joints than in synovial fluid from healthy joints, but both types of fluid had less fibronectin than in blood plasma.
A trial of 13-cis-retinoic acid for treatment of squamous cell carcinoma and preneoplastic lesions of the head in cats
Authors: Evans Anne G. , Madewell Bruce R. , Stannard Anthony A.
Published: February 2025

Ten cats with a total of 15 cancerous or precancerous lesions were examined for clinical response to and histopathologic changes after treatment with 13-cis-retinoic acid. Before treatment was started, the lesions were graded according to clinical severity and biopsied for histopathologic examination. Serum samples were prepared for determining vitamin A concentrations. For comparison, serum vitamin A concentrations in 10 clinically healthy cats were determined. 13-cis-Retinoic acid (approx 3.0 mg/kg) was given to affected cats once a day for an average of 68 days. At the completion of the therapeutic trial, additional biopsy tissues were obtained for histopathologic examination, and serum was assayed for 13-cis-retinoic acid. Of the 15 lesions examined, only 1 showed partial clinical and microscopic improvement during the therapy period. The mean serum vitamin A concentration of the affected cats was not statistically different from that of the 10 healthy cats.

The results of this trial indicated that 13-cis-retinoic acid used at this dosage, daily frequency, and duration did not have therapeutic efficacy for squamous cell carcinomas or preneoplastic lesions in the cat and that the mean serum vitamin A concentration did not differ between the affected cats and clinically healthy cats.
Antibodies to Borrelia burgdorferi in New England horses: Serologic survey
Authors: Marcus L. C. , Patterson M. M. , Gilfillan R. E. , Urband P. H.
Published: February 2025

Twelve of 50 randomly selected horses from areas endemic for Borrelia burgdorferi had indirect fluorescent antibody titers of 1:8 to 1:2,048 against B burgdorferi. One of 50 horses from nonendemic areas had a titer of 1:8. This difference in the number of horses seropositive for B burgdorferi (P < 0.002) and our finding that seropositive horses did not have agglutinating antibodies against potentially cross-reacting Leptospira spp indicated that horses in endemic areas were exposed to B burgdorferi and that the spirochete induced an antibody response in the horses.
Extraction, radioiodination, and in vivo catabolism of equine fibrinogen
Authors: Coyne Cody P. , Hornof William J. , Kelly Andrew B. , O'Brien Timothy R. , DeNardo Sally J.
Published: February 2025

Equine fibrinogen was isolated and aliquots were stored frozen at — 70 C before radiolabeling with 125I (half-life = 60.2 days; γ = 35 keV), using monochloroiodine reagent. Radioiodination efficiencies were 49% to 53%, resulting in a labeled product, with 98% protein-bound activity and 91% clottable radioactivity. In 6 equine in vivo investigations, plasma half-lives of 125I-labeled fibrinogen were from 4.1 to 5.2 days, corresponding to a mean daily plasma elimination rate of approximately 15%.
Rapid extraction, radioiodination, and in vivo catabolism of 125I-labeled fibrinogen in the horse
Authors: Coyne Cody P. , Hornof William J. , Kelly Andrew B. , O'Brien Timothy R. , DeNardo Sally J.
Published: February 2025

Two methods were analyzed for the rapid extraction of equine fibrinogen from fresh plasma, using ammonium sulfate-sodium phosphate buffer. Fibrinogen from each of these 2 methods was then radiolabeled with 125I (half-life = 60.2 days, γ = 35 keV), using monochloroiodine reagent. Mean protein-bound activity was 98.5% and mean clottable radioactivity was 94.1%. Radiolabeled fibrinogen administered 15 horses had an overall mean (± sd) plasma half-life of 4.95 ± 0.44 days.
Hybridization on bovine enterotoxigenic Escherichia coli with two heat-stable enterotoxin gene probes
Authors: Mainil Jacques , Bex Françoise , Couturier Martine , Kaeckenbeeck Albert
Published: February 2025

Hybridizations were done on bovine enterotoxigenic Escherichia coli with 2 heat-stable (ST) enterotoxin gene probes from porcine and human origin (STp and STh). Of the baby mouse-positive isolates, 56 (53%) hybridized the STp probe and 50 (47%) did not. There was no isolate that hybridized the STh probe. Hybridization with the STp probe was more frequent (P < 0.005) for E coli isolated from calves that died before 2 weeks of age (49 STp-positive isolates of 77 [64%] isolates) than for E coli isolated from calves that died after 2 weeks of age (2 STp-positive of 21 [10%] isolates).
Respiratory syncytial virus infection in transported calves
Authors: Gillette K. G. , Smith P. C.
Published: February 2025

Nasal swab samples were collected from calves on individual farms in Tennessee and sequentially at an auction barn and at a feedlot to detect respiratory syncytial virus (rsv). In 1976, rsv was isolated from 5 of 225 calves at the auction barn and from 13 of 92 calves examined at the feedlot. Of the 13 isolations, 11 were from calves with acute respiratory tract disease. Most (14/18) calves infected with rsv were also shedding parainfluenza-3 virus in their nasal secretions. Attempts to isolate rsv in the 1977 study were unsuccessful, but there was serologic evidence of rsv infection.

Most calves had serum antibody to rsv when examined initially at the farm or at the auction barn. Approximately 46% (46/99) of calves in the 1976 study and 71% (40/56) of calves in the 1977 study had a ≥ 4-fold increase in serum antibody titer to rsv from auction barn to feedlot sample collection.
Influence of dietary composition on gastric emptying and motility in dogs: Potential involvement in acute gastric dilatation
Authors: Burrows Colin F. , Bright Ronald M. , Spencer Crispin P.
Published: February 2025

Gastric dilatation-volvulus is a dramatic and life-threatening disease of large-breed dogs. The cause is unknown, but ingestion of dry cereal-based food is frequently incriminated as a predisposing factor. The purpose of this study was to examine the effect of commercial diets on gastric motility and emptying in the dog. Four large-breed dogs were fed 3 different diets (diet A = canned meat-based; B = cereal-based with 77% added water; and C = dry cereal-based) in a randomized block design. Each experiment was done in triplicate. Motility was assessed, using 5 AgAgCl electrodes and 2 strain gauges sutured along the serosa of the stomach and proximal duodenum. Dogs were fed at the same time each day and the time to change from the fed to the fasted pattern of gastrointestinal motility (changeover) was measured. Gastric emptying was assessed by recording gastric radioactivity. After feeding a meal mixed with 99mTc-labeled resin, the log of activity was plotted against time, and the half-time of gastric emptying (t1/2 ge) was calculated. Mean (± sem) times from feeding to changeover for the 3 diets were: diet A, 9.7 ± 0.9; B, 10.5 ± 0.4; and C, 11.0 ± 0.8 hours. Diet had minimal influence on the half time of gastric emptying (diet A, 2.2 ± 0.3; B, 2.6 ± 0.4; and C, 2.9 ± 0.3 hours; P > 0.05). The data indicate that gastric motility and emptying in healthy large-breed dogs were not affected by dietary composition. Because most large dogs are fed cereal-based food for reasons of cost and ease of use, these diets may have been wrongly incriminated as a predisposing factor in gastric dilatation-volvulus.
Effects of plasma sample storage on blood ammonia, bilirubin, and urea nitrogen concentrations: Cats and horses
Authors: Ogilvie Gregory K. , Engelking Larry R. , Anwer M. Sawkat
Published: February 2025

Ten horses, a pony, and 13 cats were used to evaluate base-line blood ammonia, bilirubin, and urea nitrogen concentrations and to determine the effects of prolonged cold storage (− 20 C) before assay. Base-line plasma ammonia concentrations in cats (0.992 ± 0.083 [se] μg/ml) did not change significantly after 48 hours of storage (0.871 ± 0.073 μg/ml); however, they were increased 4.2- and 13-fold after 168 and 216 hours of storage, respectively. In contrast to base-line plasma-ammonia values in cats, those of horses were significantly (0.265 ± 0.044 μg/ml) lower, and significantly increased from base-line values after 48 hours of storage (0.861 ± 0.094 μg/ml) and continued to increase 25.6-fold at 168 hours and 18.4-fold at 216 hours. Plasma urea nitrogen concentrations in cats (25.8 ± 1.06 mg/dl) and horses (11.2 ± 0.749 mg/dl) did not change significantly during 168 hours of storage. Total plasma bilirubin values from both cats (0.19 ± 0.049 mg/dl) and horses (0.75 ± 0.064 mg/dl) also did not change significantly during storage. These results indicate that feline plasma samples for ammonia determinations may be stored at − 20 C for up to 48 hours, whereas equine plasma-ammonia values tend to increase during that time. The reason for the increase remains unexplained. Both feline and equine plasma urea nitrogen and total bilirubin are stable for at least 168 hours of storage at −20 C.
Pharmacokinetics of a long-acting oxytetracycline preparation in ring-necked pheasants, great horned owls, and Amazon parrots
Authors: Teare J. Andrew , Schwark Wayne S. , Shin Sang J. , Graham David L.
Published: February 2025

After a single iv or im dose of a long-acting oxytetracycline (otc) preparation, serum concentrations were determined at various times in the ring-necked pheasant, great horned owl, and Amazon parrot. Pharmacokinetic parameters, including serum half-life (t½) and apparent volume of distribution (Vd) were calculated from the otc concentration-time curves for each species and route of administration. Significant differences (P < 0.05) were found in the t½, and Vd parameters between species and routes of administration.

Dosage regimens to maintain minimum otc concentration of 5 μg/ml of serum were calculated from the t½ and Vd values obtained, using steady-state pharmacokinetics. In the pheasant, the calculated mean IV dose was 23 mg/kg of body weight every 6 hours, whereas the mean IM dose was 43 mg/kg every 24 hours. The mean IM dose was 16 mg/kg every 24 hours for the owl and 58 mg/kg every 24 hours for the parrot.

The small volumes required for treatment, the long-dosing interval obtainable, and the broad spectrum of antimicrobial activity of the long-acting otc preparation studied offered major advantages over other antibiotics commonly used in treating avian species.
Microtechnique for quantitative platelet isolation from blood enabling electronic counting and sizing of animal and human platelets
Authors: Greene Craig E. , Prestwood Annie K. , Clark J. Derrell , Adams D. Daryl
Published: February 2025

A technique for rapidly separating platelets from small quantities of whole blood is described. The isolation method allowed for counting and sizing platelets by electronic means, and counts with this new method were closely correlated with those obtained by phase microscopy. Platelet sizing was possible because of the inert and isotonic nature of the density-gradient medium used in the procedure. The technique was applicable to samples of blood from persons, horses, cattle, sheep, goats, pigs, dogs, mice, rats, guinea pigs, and rabbits. The isolation of platelets from whole blood of various species of animals was necessary for electronic counting because of the great variation in sizes of platelets and erythrocytes and the variable sedimentation properties of animal blood.
Plasma concentrations of chloramphenicol in snakes
Authors: Clark Carl H. , Rogers E. D. , Milton J. L.
Published: February 2025

Plasma chloramphenicol concentrations after a subcutaneous injection were studied in 87 snakes of 16 different species. The biological half-life of chloramphenicol varied from 3.3 hours in the indigo snake (Drymarchon corais couperi) to 22.1 hours in the midland water snake (Nerodia sipedon). A single dosage of 50 mg of chloramphenicol/kg of body weight produced plasma concentrations > 5 μg/ml for nearly 72 hours in 2 species of water snakes (Nerodia erythrogaster, Nerodia sipedon), for 24 hours in the Burmese python (Python molurus bivittatus), and for < 12 hours in the gray rat snake, Indigo snake, and eastern king snake (Elaphe obsoleta spiloides, Drymarchon coraise couperi, and Lampropeltis getulus getulus). A dosage of 50 mg/kg administered to water snakes every 72 hours for 18 days maintained a minimum plasma concentration of chloramphenicol between 2 and 5 μg/ml.
Effects of xylazine and ketamine on the acoustic reflex and brain stem auditory-evoked response in the cat
Authors: Sims Michael H. , Horohov Janice E.
Published: February 2025

The acoustic reflex (ar) and brain stem auditory-evoked response (baer) were recorded in adult cats 5 minutes after im administration of xylazine (1 mg/kg) and after im administration of ketamine (10 mg/kg). Ipsilateral and contralateral ar were recorded at 10 and 20 dB above acoustic reflex threshold 5 minutes after xylazine administration and 5 and 35 minutes after ketamine administration. Monaural baer were recorded 5 minutes after xylazine and 5 and 35 minutes after ketamine, using stimulus intensities of 90-, 80-, and 70-dB hearing level (hl). Additional baer were recorded at 10, 15, and 25 minutes after ketamine, using the 90-dB hl stimulus. Pre- and postinjection comparisons were made for threshold, latency, and amplitude of the ar and for latency and amplitude of waves I through VI of the baer.

At both stimulus intensities before and after ketamine administration threshold for the ipsilateral reflex was significantly lower (P > 0.05) than for the contralateral reflex. The threshold, latency, and amplitude of the ar were unaffected (P > 0.05) by the injection of ketamine after xylazine. The amplitude of baer waves was not affected (P > 0.05) by ketamine after xylazine for each of the 3 stimulus intensities. Latency of the 90-dB hl-evoked response was increased (P ≤ 0.05) for waves III/IV at 5 and 35 minutes after ketamine, and for wave V at each of the post-injection times, except at post-injection minute 15. For the 80-dB hl-evoked response, wave IIL/IV latency was increased (Ρ ≤ 0.05) 5 and 35 minutes after ketamine administration. Using 70-dB hl, the latency of wave II was increased (Ρ ≤ 0.05) 5 and 35 minutes after ketamine administration. Because administration of ketamine after xylazine did not affect the ar and only minimally altered the baer, this combination of drugs should be a clinically and experimentally useful anesthetic when recording ar and baer in cats.
Modulation of arachidonic acid metabolism in endotoxic horses: Comparison of flunixin meglumine, phenylbutazone, and a selective thromboxane synthetase inhibitor
Authors: Moore J. N. , Hardee M. M. , Hardee G. E.
Published: February 2025

Two cyclooxygenase inhibitors (flunixin meglumine and phenylbutazone) and a selective thromboxane synthetase inhibitor were assessed in the management of experimental equine endotoxemia. Drugs or saline solution were administered to 16 horses 15 minutes before administration of a sublethal dose of endotoxin (Escherichia coli 055:B5). Plasma concentrations of thromboxane B2 (TxB2), prostacyclin (6-keto pgf1α), plasma lactate, and hematologic values and clinical appearance were monitored for 3 hours after endotoxin administration.

Pretreatment with flunixin meglumine (1 mg/kg of body weight) prevented most of the endotoxin-induced changes and correlated with a significant decrease in plasma TxB2 and 6-keto pgf1α concentrations, compared with concentrations in nontreated horses (ie, pretreated with saline solution). Pretreatment with phenylbutazone (2 mg/kg) attenuated the effects of endotoxin and was associated with a brief, early, significant increase in plasma TxB2 concentrations, but not in plasma 6-keto pgf1α concentrations. Pretreatment with the thromboxane synthetase inhibitor did not appear to clinically benefit the horses involved; however, arachidonic acid metabolism was redirected to prostacyclin production.
Alterations in the arrhythmogenic dose of epinephrine after adrenergic receptor blockade with prazosin, metoprolol, or yohimbine in halothane-xylazine-anesthetized dogs
Authors: Tranquilli W. J. , Thurmon J. C. , Benson G. J.
Published: February 2025

Recent evidence has linked α-receptor and β-receptor activations with ventricular arrhythmia genesis. In order to assess the relative contribution of specific adrenoceptors (αl, α2, β1) on ventricular arrhythmogenic activity during xylazine (1.1 mg·kg−1·hr−1-halothane (1.35%) anesthesia, the arrhythmogenic dose of epinephrine (ade) was repeatedly determined before and after prazosin (α1 antagonist; 0.1 mg·kg−1), metoprolol (β1 antagonist; 0.5 mg·kg−1), and yohimbine (α2 antagonist; 0.125 mg·kg−1) administration in 6 dogs. The ade was expressed as infusion rate and total dose. The ade was defined as the dose which produced 4 or more intermittent premature ventricular contractions within 15 s during a 3-minute infusion period or within 1 minute from end of infusion. Control ade was 2.69 ± 0.372 (μg·kg−1·min−1) and 4.17 ± 0.544 (μg·kg−1) for infusion rate and total dose, respectively. The ade significantly increased after prazosin (P < 0.005), metoprolol (P < 0.005), and yohimbine (P < 0.05) administration. The ade values increased to 5.42 ± 1.22 (rate) and 8.10 ± 1.95 (dose) after α2 blockade, but were significantly less than the al and β1 blockade ade values. In conclusion, although both α- and β-adrenoceptor blockade depressed ventricular arrhythmia genesis in xylazine-halothane-anesthetized dogs, α2 blockade, which was achieved with the recommended dose of yohimbine for reversal of anesthetic-induced cns depression, was not as protective as α1 (prazosin) or β1 (metoprolol) blockade.
Effects of training on muscle composition in horses
Authors: Hodgson David R. , Rose Reuben J. , Dimauro Joseph , Allen Jennifer R.
Published: February 2025

Biopsy samples were obtained from the middle gluteal muscle of 10 Thoroughbred horses undergoing a commercial race-training program. Samples were obtained before the program began and again after 6 and 12 weeks of training. All horses had raced at least once by the 12th week of training.

Serial sections of muscle were examined histochemically for myosin adenosinetriphosphatase after either acid (pH 4.3 and 4.6) or alkaline (pH 10.3) preincubation, and then muscle fibers were identified as types I, IIA, IIB, or IIC. The oxidative capacity of individual fibers was assessed, using the reduced nicotinamide dinucleotide tetrazolium-reductase stain, and the number of intermyofibrillar capillaries adjacent to each fiber were counted after staining, using the α-amylase-periodic acid-Schiff technique. Biochemical analyses involved the fluorometric measurement of 3 enzymes—citrate synthase, 3-hydroxyacyl coenzyme A dehydrogenase, and lactate dehydrogenase—as markers of end terminal oxidative, β-oxidative, and glycolytic potentials, respectively.

Changes in fiber-type percentages did not occur in response to training. There was a significant (P < 0.01) increase in the percentage of type IIB fibers, having high nicotinamide dinucleotide-tetrazolium reductase staining after 12 weeks of training. Alterations in the number of capillaries adjacent to each fiber type did not occur during the training period. There were increases in the activities of both citrate synthase and 3-hydroxy-acyl coenzyme A dehydrogenase after 6 weeks (P < 0.05) and 12 weeks (P < 0.001) of training. Alterations in the activity of lactate dehydrogenase did not occur in response to training.
Partial purification and characterization of eosinophil chemotactic factors from soluble extract of Fasciola species
Authors: Horii Yoichiro , Fujita Koichiro , Owhashi Makoto
Published: February 2025

Eosinophil chemotactic factor (ecf) was partially purified from common liver flukes (Japanese strain of Fasciola sp) by a combination of anion-exchange chromatography on DE52 and gel filtration on Sephacryl S-200. The molecular weight of ecf was estimated to be approximately 27,000 by high-pressure liquid chromatography. The ecf was heat labile (56 and 100 C for 30 minutes) and was not bound with lentil-lectin Sepharose. The results of isoelectric focusing showed that ecf comprises at least 2 components; one was a major ecf with an isoelectric point of 3.1, and the other, a minor ecf with an isoelectric point of 3.8 to 4.5. These results indicate that ecf of common liver flukes are acidic proteins.
Diagnosis of bovine respiratory syncytial virus infections improved by virus detection in lung lavage samples
Authors: Kimman T. G. , Zimmer G. M. , Straver P. J. , de Leeuw P. W.
Published: February 2025

The potential of lung lavage to diagnose and study infections with bovine respiratory syncytial virus (brsv) was investigated.

The technique was simple to perform under field conditions, and even in calves with respiratory tract disease, serious drawbacks were not observed. In 9 epizootics of respiratory tract disease, brsv infection was diagnosed in 1 or more calves. The brsv was detected from a total of 21 of 32 calves by immunofluorescence in cells recovered from lavage fluids, and the virus was recovered by cell culture from 17 of these. In the 4 remaining calves, infectious bovine rhinotracheitis virus or parainfluenza type 3 virus was isolated.

In calves with high levels of maternally derived antibodies, direct demonstration of the virus was found to be essential for making a diagnosis of brsv. In 3 of the 9 epizootics, the majority of 4- to 8-month-old calves had a significant increase in antibody concentration against brsv, whereas only a few 1- to 2-month-old calves present during the other 6 epizootics did so. However, at least in 4 of the 6 herds with younger calves, direct detection of the virus in 2 or more calves indicated that brsv was involved in the epizootic.

Cytologic examination of wash fluids from brsv-infected animals identified an increased neutrophil/large mononuclear cell ratio. Occasionally, bronchiolar casts and syncytial giant cells with inclusion bodies were seen.

In lung lavage fluids of 4 experimentally infected specific-pathogen-free calves, brsv-containing cells were detected by immunofluorescence for 12 to 18 days after inoculation.
Variation of neutrophil function with age in calves
Authors: Hauser Mark A. , Koob Michael D. , Roth James A.
Published: February 2025

Neutrophil function was evaluated on 2 occasions in 5 calves from each of the following age groups: 4 to 5 weeks, 9 to 11 weeks, 16 to 19 weeks, and 12 to 14 months. Of the neutrophil functions examined, the iodination reaction, which evaluates the activity of the myeloperoxidase-hydrogen peroxide-halide antibacterial system of the neutrophil, reflected the most marked differences among age groups. The iodination values for the 2 youngest age groups were approximately 52% of the value for the oldest cattle. This difference could not be attributed to the amount of myeloperoxidase in the neutrophil granules. Antibody-dependent cell-mediated cytotoxicity also tended to be lower in neutrophils from the 3 younger age groups. Nitroblue tetrazolium reduction, a measure of superoxide anion generation by neutrophils, was lower in the youngest age group only. The capability of neutrophils to ingest Staphylococcus aureus was higher in the 3 youngest groups of calves than in the oldest group. The observed differences in neutrophil function in young vs older calves may be partially responsible for the increased susceptibility of young calves to infectious disease.
Hepatic dearterialization in the dog
Authors: Gunn Carolyn , Gourley I. M. , Koblik Philip D.
Published: February 2025

Hepatic dearterialization was performed in 9 adult dogs. Evaluation of the technique was based on clinical and laboratory assessment of physiologic and pathologic changes related to the procedure. All dogs had hematologic and histopathologic evidence of transient hepatic ischemia that was reflected by minimal postoperative morbidity.
Characterization of effects of zearalenone in swine during early pregnancy
Authors: Long Gerald G. , Diekman Mark A.
Published: February 2025

Mature gilts (n = 16) were hand mated and randomly assigned to 1 of 4 groups of 4 gilts each. Treated gilts had 108 mg of purified zearalenone added to their diet on postmating days (pmd) 2 to 6, 7 to 10, or 11 to 15. Control gilts were given the same diet without added zearalenone. On pmd 6, 10, and 15, control gilts had venous cannulas placed in the jugular vein, and blood samples were taken at 20-minute intervals for 4 hours before feeding and 4 hours after feeding. Samples were collected from treated gilts on the last day that zearalenone was consumed. Samples were analyzed for follicle stimulating hormone, luteinizing hormone (lh), and prolactin. Single blood samples were taken by venipuncture on pmd 8, 12, 16, 20, 24, and 28 and at euthanasia and were analyzed for serum concentration of progesterone and estradiol-17β. All gilts were euthanatized 30 to 32 days after mating, and fetal development was assessed.

Three gilts that were given zearalenone on pmd 7 to 10 were not pregnant and had regressing corpora lutea on the ovaries at euthanasia. All other treated and control gilts were pregnant. Serum samples from treated gilts on pmd 10 and 15 had lower mean prolactin concentrations than did those from controls. The number of lh spikes were fewer (P < 0.05) in gilts that were given zearalenone on pmd 15 compared with those in controls on pmd 15. Serum progesterone concentrations indicated that corpora lutea regressed between pmd 20 and 28 in nonpregnant gilts. Treated gilts did not have a peak of secretion of estradiol-17β, as was observed in the controls at pmd 10 to 14. These data indicate that ingestion of 108 mg of zearalenone by gilts on pmd 7 to 10 caused embryonic death, but that this effect was not associated with changes in the serum concentration patterns of lh or follicle-stimulating hormone in samples collected several days after initiation of zearalenone treatment.
Congenital meningocele-encephalocele in an experimental swine herd
Authors: Vogt D. W. , Ellersieck M. R. , Deutsch Wayne E. , Akremi Β. , Islam Μ. Ν.
Published: February 2025

Fourteen instances of meningocele-encephalocele in an experimental herd were recorded over a 5-year period. Thirteen of these affected animals were subjected to extensive pedigree analyses. Familial associations were strong, and clearly the meningocele-encephalocele in this herd was under genetic influence. However, additional studies are needed to clarify the mode of inheritance and, perhaps, to identify other factors that might be involved.
Gastric emptying of glucose in the dog
Authors: Leib Michael S. , Wingfield Wayne E. , Twedt David C. , Williams Anne
Published: February 2025

The 30-minute gastric emptying of test meals consisting of 2.5%, 4%, 7%, 15%, or 25% glucose was evaluated in healthy, nonoperated dogs, using an orogastric intubation technique. An inversely proportional exponential relationship was found between test meal glucose concentration and amount of test meal emptied from the stomach in 30 minutes. For the 7%, 15%, and 25% glucose test meals, a mean (± sem) of 1.11 ± 0.03 kcal/min emptied into the duodenum, which represented 0.054 ± 0.004 kcal/min/kg of body weight. Test meals of 2.5% and 4% glucose supplied significantly fewer kcal per minute to the duodenum than did the other 3 meals, indicating that control of gastric emptying of hypotonic glucose meals may be different than that of isotonic or hypertonic test meals in the dog.