bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of dietary n-6-to-n-3 fatty acid ratio on complete blood and total white blood cell counts, and T-cell subpopulations in aged dogs
Authors: Hall Jean A. , Wander Rosemary C. , Gradin Joseph L. , Du Shi-Hua , Jewell Dennis E.
Published: January 2024

Objective

To determine effect of diets with variable n-6-to-n-3 fatty acid (FA) ratio on CD4+ and CD8+ T-lymphocyte subpopulations, and on results of routine laboratory analyses (CBC and total WBC count, serum biochemical analyses, and urinalysis).

Animals

20 healthy, aged (9.5 to 11.5 years old) female Beagles.

Procedure

Dogs were fed 1 of 3 diets that contained 6% fat by weight but differed in amounts of n-6 and n-3 FA. For 11 weeks, 6 dogs were fed a low concentration of n-3 FA (ratio, 31:1), 7 were fed a medium concentration (5.4:1), and 7 were fed a high concentration (1.4:1). Preprandial blood and urine samples were collected before beginning the study and at 8 weeks for evaluation of laboratory variables. Before and at 3, 6, and 8 weeks during the study, blood was drawn for total WBC and lymphocyte counts and for characterization of T-cell subpopulations. At 8 and 10 weeks, dogs were vaccinated with keyhole limpet hemocyanin suspension. Blood was drawn 4 days after each vaccination, and lymphocytes were isolated for flow cytometry. Effects of diet and vaccination on each variable were determined.

Results

After vaccination, total lymphocyte count increased and CD4+ T lymphocyte count and the CD4+-to-CD8+ ratio decreased in dogs consuming the diet with n-6-to-n-3 FA ratio of 1.4:1.

Conclusion

Feeding a diet with n-6-to-n-3 FA ratio of 1.4:1 had significant effects on CD4+ T lymphocytes in healthy, aged Beagles after vaccination. (Am J Vet Res 1999;60:319–327).
Effects of bovine serum albumin on function of cryopreserved stallion spermatozoa during medium culture and uterine tube epithelial cell coculture
Authors: Ellington Joanna E. , Samper Juan , Jones Allison , Oliver Sylvia A. , Burnett Katherine , Wright Ray W.
Published: January 2024

Objective

To compare function of cultured cryopreserved stallion spermatozoa in a modified Tyrode’s medium (TM), with or without bovine serum albumin (BSA), or in uterine tube (oviduct) epithelial cell (OEC) coculture in TM, with or without BSA.

Sample Population

Cryopreserved spermatozoa from 6 proven stallions and OEC from bovine reproductive tracts in follicular phase.

Procedure

Thawed spermatozoa were cultured in TM, with or without BSA, or cocultured with OEC monolayers in TM, with or without BSA. Percentages of capacitated and acrosome-reacted spermatozoa were measured at 5 hours for TM cultures. Spermatozoal survival and motility characteristics were observed over time for all culture methods. Number of spermatozoa attaching to OEC were compared for cocultures.

Results

Use of TM without BSA altered spermatozoal function in cell-free medium culture and OEC coculture. A higher percentage of spermatozoa were acrosome reacted in TM with BSA, although percentages of capacitated spermatozoa did not differ. Spermatozoa survived longer and maintained superior motion in TM culture without BSA and in OEC cocultures. More spermatozoa were able to attach to OEC in TM without BSA.

Conclusions

Incubation of cryopreserved spermatozoa in media with BSA resulted in rapid decrease in percentage of intact, motile spermatozoa and limited their ability to interact with OEC.

Clinical Relevance

Current culture media used for assisted reproduction techniques in horses do not provide functionally capacitated spermatozoa. Removal of BSA from such media improves spermatozoal quality and survival. (Am J Vet Res 1999;60: 363–367)
Endotoxin induction of nitric oxide synthase and cyclooxygenase-2 in equine alveolar macrophages
Authors: Hammond R. A. , Hannon R. , Frean S. P. , Armstrong S. J. , Flower R. J. , Bryant C. E.
Published: January 2024

Objective

To determine the amount of cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) enzymes induced in vitro in equine alveolar macrophages in response to lipopolysaccharide (LPS).

Sample Population

Alveolar macrophages obtained from 12 horses.

Procedure

Alveolar macrophages were collected by bronchoalveolar lavage from 12 horses and incubated for 6 hours with LPS (0.001 to 10 µg/ml) or vehicle. Total RNA was extracted and purified. After first-strand cDNA synthesis, mRNA induction was measured, using a polymerase chain reaction (PCR) technique for COX-2, iNOS, and glyceraldehyde 3-phosphate dehydrogenase. In a second study, cells were incubated with LPS or vehicle for 24 hours. Culture medium was assayed for COX-2 and iNOS activity by determining prostaglandin E2 (PGE2) and total nitrite concentrations, respectively.

Results

Lipopolysaccharide induces COX-2 and iNOS mRNA in equine alveolar macrophages. Sequencing revealed that PCR products for COX-2 and iNOS had a high degree of nucleotide homology with the human sequences (91% COX-2, 93% iNOS). Production of mRNA for COX-2 and iNOS was accompanied by induction of enzyme activity. Comparing PCR fragment production, expression of mRNA for iNOS appeared to be less than that for COX-2. Induction of COX-2, but not iNOS, was LPS-concentration dependent.

Conclusion

Lipopolysaccharide induces COX-2 and iNOS in equine macrophages.

Clinical Relevance

The induction of iNOS and COX-2 by LPS in equine macrophages suggests these enzymes may be important in the pathophysiology of sepsis. Pharmacologic modulation of iNOS and COX-2 activity may represent a novel therapeutic target in the management of endotoxemia in horses. (Am J Vet Res 1999;60:426-431)
Lipid peroxides and antioxidants in serum of neonatal calves
Authors: Inanami Osamu , Shiga Akio , Okada Keiji , Sato Reeko , Miyake Yoh-ich , Kuwabara Mikinori
Published: January 2024

Objective

To examine the association between oxidative stress and antioxidants in neonatal calves after birth.

Sample Population

Sera from 6 healthy Holstein-Friesian cows and 7 of their newborn calves were obtained at various intervals after birth.

Procedure

Lipid peroxides in serum of cows and their newborn calves were estimated by measuring concentrations of thiobarbituric acid-reactive substances (TBARS). The antioxidative activities of neonatal sera were evaluated by measuring their superoxide-scavenging activities, ferroxidase activities, and the concentration of bilirubin-associated albumin.

Results

Concentration of TBARS in neonatal sera within 1 day after birth was significantly higher than concentrations ≥ 2 days after birth and concentrations in serum of the dams. In contrast, antioxidative activities of neonatal sera, evaluated on the basis of superoxide-scavenging activities, ferroxidase activities, and concentration of bilirubin-associated albumin 3 hours after birth, were significantly lower than antioxidative activities in sera of the dams.

Conclusions

Susceptibility of calves to oxidative stress during the neonatal period may be explained by the immature defense system against superoxide radicals. (Am J Vet Res 1999;60:452-457)
In vitro efficacy of N-duopropenide, a recently developed disinfectant containing quaternary ammonium compounds, against selected gram-positive and gram-negative organisms
Authors: Gutiérrez C. B. , Álvarez D. , Rodríguez-Barbosa J. I. , Tascón R. I. , de la Puente V. A. , Rodríguez-Ferri E. F.
Published: January 2024

Objective

To study the efficacy of N-duopropenide against various gram-positive and gram-negative organisms.

Sample Population

One field strain each of Pasteurella multocida subsp multocida, Staphylococcus aureus, Listeria monocytogenes, and L ivanovii, and 2 field strains of Escherichia coli.

Procedure

Strains were tested with and without serum as organic matter, using quantitative suspension and carrier tests. Six concentrations of active ingredient (0.005, 0.01, 0.05, 0.11, 0.27, and 0.55%) and 6 contact times (15 and 30 seconds and 1, 3, 5, and 10 minutes) were studied for each.

Results

Globally, N-duopropenide was more effective in suspension tests than in carrier tests, and when organisms were suspended in saline solution rather than serum. Under the most disadvantageous conditions (carrier test with serum), a concentration of 0.55% N-duopropenide acting for only 15 seconds was effective in inactivating P multocida subsp multocida and was even more effective against the 2 Listeria species tested. For E coli strains, the same concentration also was effective, but after 10 minutes of contact. On the other hand, N-duopropenide was unable to inactivate the S aureus strain in the carrier test with serum, a concentration of 0.55% for 10 minutes was necessary to inactivate it without organic matter; however, N-duopropenide was highly effective against this organism in the suspension test, even with serum.

Conclusion

N-duopropenide was highly effective in vitro against 5 of the most commonly encountered organisms in clinical veterinary medicine and, consequently, might be a good choice in control measures against common pathogenic organisms in modern production systems. (Am J Vet Res 999:60:481-484)
Effect of sampling site, repeated sampling, pH, and Pco2 on plasma lactate concentration in healthy dogs
Authors: Hughes Dez , Rozanski Elizabeth R. , Shofer Frances S. , Laster Larry L. , Drobatz Kenneth J.
Published: January 2024

Objective

To characterize the variation in plasma lactate concentration among samples from commonly used blood sampling sites in conscious, healthy dogs.

Animals

60 healthy dogs.

Procedure

Cross-sectional study using a replicated Latin square design. Each dog was assigned to 1 of 6 groups (n = 10) representing all possible orders for 3 sites (cephalic vein, jugular vein, and femoral artery) used to obtain blood. Samples were analyzed immediately, by use of direct amperometry for pH, Po2, Pco2, glucose, and lactate concentration.

Results

Significant differences in plasma lactate concentrations were detected among blood samples from the cephalic vein (highest), femoral artery, and jugular vein (lowest). Mean plasma lactate concentration in the first sample obtained, irrespective of sampling site, was lower than in subsequent samples. Covariation was identified among plasma lactate concentration, pH, and Pco2, but correlation coefficients were low.

Conclusions and Clinical Relevance

Plasma lactate concentrations differed among blood samples from various sites. A reference range for plasma lactate concentration was 0.3 to 2.5 mmol/L. Differences in plasma lactate concentrations among samples from various sites and with repeated sampling, in healthy dogs, are small. Use of the reference range may facilitate the clinical use of plasma lactate concentration in dogs. (Am J Vet Res 1999; 60:521-524)
Effect of acute gastric dilatation on gastric myoelectric and motor activity in dogs
Authors: Hall Jean A. , Solie Thomas N. , Seim Howard B. , Twedt David C.
Published: January 2024

Objective

To investigate the effects of experimentally induced acute gastric dilatation on electrical and mechanical activities of the stomach in dogs.

Animals

7 healthy dogs.

Procedure

Electrodes and strain-gauge force transducers were implanted on the serosal surface of the antrum and pylorus. Eight days later, baseline gastric electrical and contractile activities were recorded. The dogs were anesthetized and mechanically ventilated to maintain normocapnia while the stomach was distended (intragastric pressure, 30 mm Hg) for 180 minutes, using a thin compliant bag. Gastric electrical and contractile activities were recorded again on days 1 and 10 after dilatation. Recordings were analyzed to determine gastric slow-wave frequency, slow-wave dysrhythmia, propagation velocity of slow-waves, coupling of contractions to slow waves, motility index on the basis of relative contractile amplitudes, and onset of contractions after a standardized meal.

Results

Electrical or contractile activities were not significantly different 18 hours after acute gastric dilatation (day 1). Arrhythmias were evident before and after gastric dilatation in dogs from which food was withheld and in dogs after consumption of a meal.

Conclusions

Variables for assessing gastric electrical and contractile activities were unaffected 18 hours after acute gastric dilatation.

Clinical Relevance

Analysis of results of this study indicated that altered electrical and contractile activities in dogs with short-term gastric dilatation are not likely to be secondary to the process of acute gastric dilatation. (Am J Vet Res 1999;60:597–602)
Experimental infection of calves with epizootic hemorrhagic disease virus
Authors: Abdy Mark J. , Howerth Elizabeth E. , Stallknecht David E.
Published: January 2024

Objective

To determine whether experimental inoculation with a field strain of epizootic hemorrhagic disease virus serotype-2 (EHDV-2) suspected of causing clinical disease in naturally infected cattle would cause clinical disease in calves.

Animals

8 calves.

Procedure

A strain of EHDV-2 isolated from a white-tailed deer that died of hemorrhagic disease was passaged twice in deer and used to inoculate 6 calves SC and ID; the other 2 calves were used as controls. Physical examinations, CBC, lymphocyte blastogenesis assays, and coagulation assays were performed; rectal temperature, interferon production, and serum neutralizing antibody responses were measured; and virus isolation was attempted every other day for 21 days after inoculation and then every fourth day for another 30 days. Calves were euthanatized on postinoculation day 51, and necropsy was performed.

Results

Calves inoculated with EHDV-2 became infected, as evidenced by development of viremia and seroconversion. However, the virus did not cause detectable clinical disease, clinicopathologic abnormalities, or gross lesions. Viremia was prolonged despite development of a serum neutralizing antibody response. A white-tailed deer inoculated with the same EHDV-2 strain developed clinical signs of epizootic hemorrhagic disease, demonstrating that the inoculum was virulent.

Conclusion

Calves experimentally infected with EHDV-2 developed viremia and seroconverted but did not develop detectable clinical disease. (Am J Vet Res 1999;60:621–626)
Superoxide production in phagocytes obtained from Mycobacterium marinum-stimulated goldfish (Carassius auratus) that were exposed to copper
Authors: Jacobson Susanne V. , Trucksis Michele , Kane Andrew S. , Reimschuessel Renate
Published: January 2024

Objective

To investigate the effects of copper exposure and recovery from copper toxicosis on the nonspecific immune response in Mycobacterium marinum-inoculated goldfish.

Animals

Goldfish (Carassius auratus) with a mean weight of 33.5 g.

Procedure

Superoxide (O2-) production was measured in fish 2 to 6 weeks after injection with phosphate-buffered saline (PBS) solution or M marinum (102 to 107 colony-forming units [CFU]/fish). Then, paired groups of fish were injected with PBS solution or 104 CFU of M marinum and exposed to copper (100 µg/L) for 7 days or for 4 days with 3 days of recovery. One paired group not exposed 14 days later to copper served as control fish. Phagocyte production of O2-was measured by use of the nitroblue tetrazolium reduction assay. Inflammation and bacterial colony counts were determined by use of routine histologic and microbiologic procedures.

Results

Superoxide production achieved a maximal response 2 to 4 weeks after M marinum inoculation. Compared with control fish, O2- production increased in the groups exposed to copper but then decreased in the exposed groups that were allowed to recover. Superoxide response and peritoneal inflammation were greater in M marinum-inoculated groups than in non-inoculated groups.

Conclusions

Copper exposure and inoculation with M marinum increased O2- production, whereas recovery after exposure decreased O2- production, even in fish that were immunostimulated by M marinum.

Clinical Relevance

When the antimicrobial oxidative response is suppressed after copper exposure, steps should be taken to avoid imposing additional stress and minimize the possibility of resurgent or secondary pathogenic infections. (Am J Vet Res 1999;60:669–675)
Effect of alternate-day prednisolone administration on hypophyseal-adrenocortical activity in dogs
Authors: Brockus Charles W. , Dillon Allen R. , Kemppainen Robert J.
Published: January 2024

Objective

To evaluate effect of alternate-day oral administration of prednisolone on endogenous plasma ACTH concentration and adrenocortical response to exogenous ACTH in dogs.

Animals

12 Beagles.

Procedure

Dogs were allotted to 2 groups (group 1, 8 dogs treated with 1 mg of prednisolone/kg of body weight; group 2, 4 dogs given excipient only). During a 30-day period, blood samples were collected for determination of plasma ACTH and Cortisol concentrations before, during, and after treatment with prednisolone. From day 7 to 23, prednisolone or excipient was given on alternate days. Sample collection (48-hour period with 6-hour intervals) was performed on days 1, 7, 15, 21, and 28; on other days, sample collection was performed at 24-hour intervals. Pre-and post-ACTH plasma Cortisol concentrations were determined on days 3, 9, 17, 23, and 30.

Results

A significant difference was detected between treatment and time for group 1. Plasma ACTH concentrations significantly decreased for 18 to 24 hours after prednisolone treatment in group-1 dogs. At 24 to 48 hours, ACTH concentrations were numerically higher but not significantly different in group-1 dogs. Post-ACTH plasma Cortisol concentration significantly decreased after 1 dose of prednisolone and became more profound during the treatment period. However, post-ACTH Cortisol concentration returned to the reference range 1 week after prednisolone administration was discontinued.

Conclusions and Clinical Relevance

Single oral administration of 1 mg of prednisolone/kg significantly suppressed plasma ACTH concentration in dogs for 18 to 24 hours after treatment. Alternate-day treatment did not prevent suppression, as documented by the response to ACTH. (Am J Vet Res 1999;60:698–702)
Use of breath hydrogen testing to detect experimentally induced disaccharide malabsorption in healthy adult dogs
Authors: Spohr Anette , Guilford W. Grant , Haslett Stephen J. , Vibe-Petersen Gunvor
Published: January 2024

Objective

To develop a noninvasive method to detect disaccharide malabsorption in dogs by measuring hydrogen concentration ([H2]) in exhaled breath before and after experimentally induced disaccharide malabsorption.

Animals

8 healthy mixed-breed dogs.

Procedure

[H2] was measured every 30 minutes for 8 hours after administration of disaccharide solutions (lactose, 0.5 g/kg of body weight; lactose, 1.0 g/kg; sucrose, 2.0 g/kg; maltose, 1.5 g/kg; and lactose [0.5 g/kg] and sucrose [2.0 g/kg]) to determine reference ranges of [H2] for each solution, which were compared with [H2] in dogs with experimentally induced disaccharide malabsorption. To induce disaccharide malabsorption, dogs were given a mild overdose of lactose (1.5 g/kg) or a disaccharidase inhibitor. In the latter experiment, acarbose (10 mg/kg, PO) was given with the combination of lactose (0.5 g/kg) and sucrose (2 g/kg), and with maltose (1.5 g/kg).

Results

Overdosing with lactose resulted in [H2] persistently outside the reference range for lactose in 5 of 8 dogs. Acarbose administration resulted in [H2] persistently outside the reference range in 7 of 8 dogs that received a combination of sucrose and lactose but did not consistently affect [H2] after administration of maltose.

Conclusions

Disaccharide malabsorption resulted in [H2] outside the reference ranges in most of the adult dogs studied, suggesting that the technique may be useful in detecting naturally occurring disaccharidase deficiency. (Am J Vet Res 1999;60:836–840)
Complementary DNA cloning, tissue distribution, and synthesis of canine brain natriuretic peptide
Authors: Asano Kazushi , Murakami Masaaki , Endo Daiji , Kimura Takashi , Fujinaga Toru
Published: January 2024

Objective

To determine complimentary DNA (cDNA) sequence and tissue distribution of canine brain natriuretic peptide (BNP), and to investigate whether synthesis of canine BNP increases in association with cardiovascular dysfunction.

Animals

5 healthy adult mixed-breed dogs and 3 healthy adult Beagles.

Procedure

Total RNA was extracted from normal canine hearts and was used in a reverse transcription-polymerase chain reaction (RT-PCR) procedure to isolate canine BNP cDNA. Sequence of the isolated cDNA was analyzed. Gene expression of canine BNP in various tissues from 2 mixed-breed dogs was investigated, using RT-PCR and northern blot analyses. Moreover, messenger RNA (mRNA) expression of canine BNP, using northern blot analysis, was compared between grossly normal hearts from 3 Beagles and hearts from 3 mixed-breed dogs with acute myocardial infarction created by surgical ligation.

Results

The cDNA sequence and deduced amino acid residues of canine BNP precursor were 420 base pairs and 140 residues, respectively. Messenger RNA expression of canine BNP was detectable in the atria but not in the ventricles and the other tissues. Messenger RNA expression of canine BNP was, however, detectable in the infarcted portion of the ventricles. The amount of canine BNP mRNA in the infarcted ventricles was significantly increased, compared with that of noninfarcted ventricles.

Conclusion

The cDNA sequence of canine BNP was determined. Expression of canine BNP mRNA was detected not only in the atria but also in infarcted ventricles. Synthesis of canine BNP increases in association with ischemic myocardial injury. Canine BNP may be used as an indicator of severity of ventricular myocardial injury. (Am J Vet Res 1999;60:860–864)
Biosafety and antibody responses of adult bison bulls after vaccination with Brucella abortusstrain RB51
Authors: Olsen Steven C. , Rhyan J. C. , Gidlewski Thomas , Palmer M. V. , Jones A. H.
Published: January 2024

Objective

To evaluate clearance, antibody responses, potential shedding, and histologic lesions in reproductive tissues of adult bison bulls after vaccination with Brucella abortus strain RB51.

Animals

61 two- and 3-year-old bison bulls.

Procedure

12 bison bulls were vaccinated SC with B abortus strain RB51, 3 were inoculated SC with 0.15M NaCI, and antibody responses were evaluated. Various specimens were obtained to evaluate bacterial shedding. Four vaccinates and 1 control were necropsied 10, 20, and 30 weeks after vaccination. In a separate experiment, bison bulls were vaccinated SC with 0.15M NaCI, or by hand or ballistically with strain RB51. Antibody responses were monitored 6 weeks after vaccination and during necropsy 13 weeks after vaccination. Tissue specimens obtained during necropsy from both studies were evaluated bacteriologically and histologically.

Results

Strain RB51 was recovered at various times from semen of 3 of 12 vaccinated bison bulls in experiment 1. During necropsy, strain RB51 was recovered 10 and 20, but not 30, weeks after vaccination. In experiment 2, strain RB51 was recovered from lymphoid tissues of hand- and ballistic-vaccinated bison bulls during necropsy. In both experiments, microscopic lesions in testes, epididymis, and seminal vesicles were minimal and did not differ between strain RB51-vaccinated and saline-inoculated bison bulls.

Conclusions and Clinical Relevance

Strain RB51 does not induce relevant inflammatory lesions in reproductive tissues of adult bison bulls. Shedding of strain RB51 in semen may be transient in some bison bulls; however, the importance of this observation is unknown. (Am J Vet Res 1999;60:905–908)
Characterization of parasympatholytic chronotropic responses following intravenous administration of atropine to clinically normal dogs
Authors: Rishniw Mark , Kittleson Mark D. , Jaffe Rory S. , Kass Philip H.
Published: January 2024

Objective

To determine heart rate (HR) and heart rate variability (HRV) after IV administration of 3 doses of atropine to clinically normal, large-breed adult dogs.

Animals

6 mixed-breed dogs, weighing between 23 and 50 kg.

Procedure

Continuous ECG were recorded prior to and following IV administration of saline (0.9% NaCl) solution and 0.02, 0.04, and 0.06 mg of atropine/kg of body weight. Heart rate and HRV within sympathetic and parasympathetic domains were determined, using customized software, and responses to treatments were compared. Each dog received all treatments with ≥ 2 days between treatments.

Results

HR increased and HRV within the parasympathetic domain decreased after all atropine treatments, compared with pretreatment values. Heart rate was significantly higher after administration of 0.06 mg of atropine/kg than after 0.02 mg/kg but was not different from HR after administration of 0.04 mg/kg. Five of 6 dogs given the 0.04 or 0.06 mg/kg dose attained HR > 135 beats/min, but only 1 of 6 dogs given the 0.02 mg/kg dose attained a HR > 135 beats/min. Heart rate variability within the parasympathetic domain decreased significantly from pretreatment values after all atropine treatments. Atropine doses of 0.04 and 0.06 mg/kg induced significantly lower HRV than did the 0.02 mg/kg dose, but HRV after the higher doses were not different from each other. HRV within the sympathetic domain after any treatment did not change from pretreatment values.

Conclusions and Clinical Relevance

IV administration of 0.04 or 0.06 mg of atropine/kg increased HR and induced complete parasympathetic blockade in clinically normal, large-breed adult dogs. (Am J Vet Res 1999;60:1000-1003)
Efficacy of florfenicol in the treatment of experimentally induced infectious bovine keratoconjunctivitis
Authors: Dueger Erica L. , Angelos John A. , Cosgrove Sallie , Johnson John , George Lisle W.
Published: January 2024

Objective

To evaluate efficacy of florfenicol in an induced model of infectious bovine keratoconjunctivitis, using a blinded randomized, controlled trial.

Animals

48 male Holstein calves, 2 to 4 months old.

Procedure

Moraxella bovis infection was induced in all calves. When corneal ulcers developed, each calf was assigned randomly to 1 of 3 treatment groups, using a block design determined by corneal ulcer size (day 0). Calves were treated with florfenicol (20 mg/kg of body weight, IM) on days 0 and 2 (IM group; n = 16). Calves of a second group received a single dose of florfenicol (40 mg/kg, SC) on day 0 (SC group; n = 16). The third group of calves was not treated (control group; n = 16). Corneal ulcers were photographed, and each calf was assessed for 30 days after treatment for 10 clinical signs of infection. Corneal ulcer surface areas were measured, and clinical scores were calculated. Ocular secretions for microbiologic culture were obtained weekly from each eye.

Results

A Cox regression model indicated that, after adjustment for initial ulcer size, healing rates were 6.2 and 4.8 times greater in calves of the IM and SC groups, respectively, compared with the control group. Clinical scores and surface area measurements for treatment groups were significantly smaller than those for controls during posttreatment weeks 1 through 4. From day 8 through day 29, M bovis was isolated from ocular secretions of 14 of 16 control calves and 1 of 32 treated calves.

Conclusions and Clinical Relevance

Parenterally administered florfenicol reduces corneal ulcer healing time, lessens clinical severity, and reduces the amount of bacterial shedding from calves infected with M bovis. (Am J Vet Res 1999;60:960-964)
Efficacy of misoprostol in prevention of gastric hemorrhage in dogs treated with high doses of methylprednisolone sodium succinate
Authors: Rohrer Cécile R. , Hill Richard C. , Fischer Andrea , Fox Leslie E. , Schaer Michael , Ginn Pamela E. , Preast Vanessa A. , Burrows Colin F.
Published: January 2024

Objective

To determine whether administration of misoprostol prevents gastric hemorrhage in healthy dogs treated with high doses of methylprednisolone sodium succinate (MPSS).

Animals

18 healthy hound-type dogs of both sexes.

Procedure

All dogs were given high doses of MPSS (30 mg/kg of body weight, initially, then 15 mg/kg 2 and 6 hours later, and, subsequently, q 6 h for a total of 48 hours) IV. Dogs were assigned randomly to receive concurrent treatment with misoprostol (4 to 6 μg/kg, PO, q 8 h; n = 9) or an empty gelatin capsule (9). Gastroduodenoscopy was performed before and after treatment. Hemorrhage was graded from none (0) to severe (3) for each cardia, fundus, antrum, and duodenum. A total stomach score was calculated as the sum of the regional stomach scores. Food retention was recorded, and pH of gastric fluid was determined. Gastric and fecal occult blood was measured.

Results

Gastric hemorrhage was evident in all dogs after MPSS administration, and its severity was similar in both groups. Median total stomach score was 6 for misoprostol-treated dogs and 5.5 for dogs given the gelatin capsule. Difference in gastric acidity, frequency of food retention, and incidence of occult blood in gastric fluid and feces was not apparent between the 2 groups.

Conclusions and Clinical Relevance

Administration of misoprostol (4 to 6 μg/kg, PO, q 8 h) does not prevent gastric hemorrhage caused by high doses of MPSS. Alternative prophylactic treatment should be considered. (Am J Vet Res 1999;60:982–985)
Duration of action and hemodynamic properties of mivacurium chloride in dogs anesthetized with halothane
Authors: Smith Lesley J. , Moon Paula F. , Lukasik Victoria M. , Erb Hollis N.
Published: January 2024

Objective

To describe onset and duration of neuromuscular blockade induced by mivacurium chloride and its associated hemodynamic effects at 3 dosages in healthy dogs.

Animals

7 Labrador Retrievers.

Procedure

Anesthesia was induced with thiopental and maintained with halothane in oxygen, and dogs were mechanically ventilated to end-tidal PCO2 between 35 and 40 mm Hg. Core temperature, end-tidal PCO2, and halothane concentration were kept constant throughout the experiment. Neuromuscular function was assessed by evaluation of the train-of-four response to a supramaximal electrical stimulus of 2 Hz applied to the ulnar nerve every 10 seconds. Blood for determination of plasma cholinesterase activity was obtained prior to administration of mivacurium, a bolus of which was administered IV, using a randomized Latin-square design for dosages of 0.01, 0.02, and 0.05 mg/kg of body weight.

Results

All dogs had typical plasma cholinesterase activity. After administration of mivacurium, differences were not evident between groups in heart rate, systolic, mean, or diastolic blood pressure, change at any time in heart rate, systolic, mean, or diastolic blood pressure, or pH. Interval from onset to 100% neuromuscular blockade was 3.92 ± 1.70, 2.42 ± 0.53, and 1.63 ± 0.25 minutes at dosages of 0.01, 0.02, and 0.05 mg/kg, respectively. Duration of measurable neuromuscular blockade was 33.72 ± 12.73, 65.38 ± 12.82, and 151.0 ± 38.50 minutes, respectively. Time of onset and duration of effect differed significantly among dosages.

Conclusions and Clinical Relevance

Mivacurium provides good hemodynamic stability at the dosages tested. In dogs, this drug has a rapid onset and long duration of effect. (Am J Vet Res 1999;60:1047-1050)
Effects of tylosin on concentrations of Fusobacterium necrophorum and fermentation products in the rumen of cattle fed a high-concentrate diet
Authors: Nagaraja Tiruvoor G. , Sun Yude , Wallace Neil , Kemp Ken E. , Parrott Calvin J.
Published: January 2024

Objective

To determine effects of tylosin on ruminal concentrations of Fusobacterium necrophorum and fermentation products in cattle during rapid adaptation to a high-concentrate diet.

Animals

6 steers fitted with ruminal cannulas.

Procedure

Steers were assigned randomly to 2 treatment groups and switched from a 0 to an 85% concentrate diet during a 4-day period. Cattle received this diet, with or without tylosin (90 mg/steer/d), for 4 weeks. Samples of ruminal contents were collected daily beginning 2 days before the treatment protocol and in the first week of concentrate feeding. Four subsequent samples were collected at weekly intervals. Concentration of F necrophorum in samples was determined, using the most-probable-number technique. Ruminal pH and concentrations of volatile fatty acids (VFA), lactate, and ammonia also were determined. All steers received both treatments separated by 4 weeks (cross-over design), during which time they were fed alfalfa hay only.

Results

In control steers, concentration of F necrophorum increased in response to the high-concentrate diet. Tylosin-fed steers had lower concentrations of F necrophorum than control steers at all times during concentrate feeding. However, ruminal pH and concentrations of lactate, VFA, and ammonia did not differ between treatment groups.

Conclusions and Clinical Relevance

Tylosin caused a significant reduction in ruminal concentrations of F necrophorum during rapid adaptation to a high-concentrate diet but had no effect on fermentation products. The reduction in ruminal concentration of F necrophorum helps explain the reduction in prevalence of hepatic abscesses reported in tylosin-fed feedlot cattle. (Am J Vet Res 1999;60:1061-1065)
Comparison of intra-articular injection of 2 ml of 0.9% NaCl solution with rest alone for treatment of horses with traumatic arthritis
Authors: Gaustad Gudrun , Dolvik Nils Ivar , Larsen Stig
Published: January 2024

Objective

To compare effects of intra-articular injection of 2 ml of 0.9% NaCl solution with rest alone for treatment of horses with traumatic arthritis.

Animals

38 Standardbred horses with moderate to severe lameness that resulted from traumatic arthritis.

Procedure

Horses were stratified on the basis of number of affected joints. In each stratum, horses were allocated randomly to treatment groups (intra-articular injection of 2 ml of 0.9% NaCl solution vs rest only). Treatment was for a period of 3 weeks. Horses were inspected weekly with a final examination 2 to 4 weeks after completion of treatment.

Results

Mean lameness index was significantly lower during the 3-week treatment period and the entire study period for the NaCl-injected group. A significant decrease in the lameness index during the first 3-week treatment period also was detected for the rest-only group; however, the lameness index increased significantly for this group during the follow-up period, and an overall significant decrease was not detected. Comparison of the lameness index curve indicated a difference in favor of NaCl injection, with a significant difference between the 2 groups at final examination. Nine horses became sound during treatment with rest only, but 6 relapsed before final examination. In the NaCl-injected group, 5 of 10 sound horses relapsed.

Conclusions and Clinical Relevance

Intra-articular injection of 2 ml of 0.9% NaCl solution was beneficial in horses with traumatic arthritis. Use of rest alone for a limited period was inadequate for treatment of young Standardbred horses with traumatic arthritis. (Am J Vet Res 1999;60:1117–1121)
Effect of a magnesium-deficient diet on serum and urine magnesium concentrations in healthy cats
Authors: Norris Carol R. , Christopher Mary M. , Howard Kimberly A. , Nelson Richard W.
Published: January 2024

Objective

To evaluate the efficacy of using serum total and ionized magnesium (Mg) concentrations and urine Mg concentrations to identify Mg deficiency in cats.

Animals

6 healthy castrated male cats.

Procedure

A Mg-replete diet was fed for 37 days, followed by a Mg-deficient diet for 37 days. On days 1, 3, and 7 of the last week of each diet, serum ionized and total Mg concentrations were determined; in addition, urine Mg concentration was determined each day of the last week. Serum total and ionized Mg concentrations were compared with urine Mg concentration, amount of Mg excreted during 24 hours (24-hour urine Mg excretion), ratio of urine Mg concentration to urine creatinine concentration (Umg:Ucr), and urinary fractional excretion of Mg (FEmg) to determine which variable best predicted Mg status.

Results

Cats fed Mg-deficient diets had significantly lower serum total and ionized Mg concentrations and 24-hour urine Mg excretion values, compared with cats fed Mg-replete diets. Serum total Mg concentration was the best predictor of Mg status. Twenty-four-hour urine Mg excretion was a repeatable, reliable measurement and had the best correlation with serum total Mg concentration. Serum total Mg concentration also correlated with urine Mg concentration, Umg:Ucr, and FEmg.

Conclusions and Clinical Relevance

Serum total and ionized Mg concentrations can be used to identify cats with dietary-induced Mg deficiencies. Twenty-four-hour urine Mg excretion and urine Mg concentration correlated best with serum total Mg concentration and, therefore, may be the most useful urine variables for identifying Mg deficiency. (Am J Vet Res 1999;60:1159–1163)
Effects of ear type, sex, age, body weight, and climate on temperatures in the external acoustic meatus of dogs
Authors: Huang Hui-Pi , Huang Hui-Mei
Published: January 2024

Objective

To investigate effects of ear type, sex, age, body weight, and ambient climatic conditions on external acoustic meatus (external ear canal) temperatures in dogs.

Animals

650 dogs without clinical signs of ear disease.

Procedure

Dogs were assigned to 5 groups on the basis of auricular conformation and amount of hair in the external ear canal and 4 groups on the basis of body weight or age. External ear canal temperatures (EECT) were measured, using an infrared thermometer. Mean EECT determined for each group were compared to evaluate effects of ear type, age, weight, and sex, and EECT measured at different ambient temperatures and humidities were compared to determine climatic effects

Results

Dogs with hirsute ear canals had significantly lower EECT than dogs with hairless ear canals, whereas significant differences were not detected between dogs with erect and pendulous auricles. Dogs < 6 years old had higher EECT than older dogs, and dogs that weighed < 6 kg had lower EECT than larger dogs. External ear canal temperatures measured when ambient temperatures were < 25 C were less than those measured at warmer temperatures. Sex and relative humidity did not affect EECT.

Conclusions and Clinical Relevance

EECT of dogs without ear disease were affected by weight and age, amount of hair in the external ear canal, and ambient temperature. However, hirsute ears had lower, not higher, EECT than hairless ears, suggesting that EECT may play less of a role in the development of otitis externa than believed. (Am J Vet Res 1999;60:1173-1176)
Factors associated with time until first race and career duration for Thoroughbred racehorses
Authors: Bailey Craig J. , Reid Stuart W. J. , Hodgson David R. , Rose Reuben J.
Published: January 2024

Objective

To determine whether sex or foaling period were associated with time to first race start and whether sex, age at time of first race start, or interrace period were associated with career duration for Thoroughbred racehorses in Australia.

Animals

553 Thoroughbred racehorses.

Procedure

Race records through to the end of the 6-year-old racing season were obtained for each horse. Product-limit survival analysis was used to determine whether sex or foaling period was associated with time to first race start and whether sex or age at first race was associated with career duration. A Cox proportional hazards model was used to determine whether sex, age at first possible race, age at first race, or inter-race period was associated with time to first race start or career duration.

Results

472 horses (85.4%) raced. Time to first race start was not associated with sex or foaling period. However, males, who had their first race at a younger age and a greater mean number of rest days between races, had longer careers. The hazard ratio for career duration of males versus females, controlling for age at time of first race and inter-race period (0.27), confirmed that males had a higher probability of a long racing career.

Conclusions and Clinical Relevance

Results suggest that for Thoroughbred racehorses, sex and time of birth during the foaling season were not associated with time to first race. Male Thoroughbred racehorses that were raced less intensively or raced at a younger age were more likely to have long racing careers. (Am J Vet Res 1999;60:1196–1200)
Cardiopulmonary and sedative effects of intravenous administration of low doses of medetomidine and xylazine to adult horses
Authors: Bueno Aloisio C. , Cornick-Seahorn Janyce , Seahorn Thomas L. , Hosgood Giselle , Moore Rustin M.
Published: January 2024

Objective

To determine the cardiopulmonary and sedative effects of medetomidine hydrochloride in adult horses and to compare those effects with effects of an equipotent dose of xylazine hydrochloride.

Animals

10 healthy adult female horses.

Procedure

5 horses were given medetomidine (4 μg/kg of body weight, IV), and the other 5 were given xylazine (0.4 mg/kg, IV). Heart rate, respiratory rate, arterial blood pressures, pulmonary arterial blood pressures, and cardiac output were recorded, and sedation and ataxia scores were assigned before and every 5 minutes after drug administration for 60 minutes. Rectal temperature and blood gas partial pressures were measured every 15 minutes after drug administration.

Results

Arterial blood pressure was significantly decreased throughout the study among horses given medetomidine and was significantly decreased for 40 minutes among horses given xylazine. Compared with baseline values, cardiac output was significantly decreased 10, 20, and 40 minutes after administration of medetomidine and significantly increased 40 and 60 minutes after administration of xylazine. Despite the significant decrease in respiratory rate in both groups, results of blood gas analyses were not significantly changed over time. Ataxia and sedation scores were of similar magnitude for the 2 groups, but ataxia persisted slightly longer among horses given medetomidine. Horses resumed eating hay 10 to 55 minutes after drug administration.

Conclusions and Clinical Relevance

Results suggest that equipotent low doses of medetomidine and xylazine induce comparable levels of ataxia and sedation and similar cardiopulmonary changes in adult horses. (Am J Vet Res 1999;60:1371–1376)
Effect of partial ureteral obstruction on results of renal scintigraphy in dogs
Authors: Barthez Paul Y. , Smeak Daniel D. , Wisner Erik R. , Duffey Marcie , Chew Dennis J. , DiBartola Stephen P.
Published: January 2024

Objective

To use scintigraphy to determine the effects of partial ureteral obstruction on renal transit time and induction of diuresis in dogs.

Animals

8 adult dogs.

Procedure

Scintigraphy was performed, using technetium Tc 99m diethylenetriaminepentacetic acid (Tc 99m-DTPA), before and within 2 weeks after surgical induction of unilateral partial ureteral obstruction. Time of peak (TOP) for the parenchyma (pTOP) and whole kidney (wTOP) and mean-transit time (MTT) for the parenchyma (pMTT) and whole kidney (wMTT) were determined by evaluation of renal time-activity curves before and after deconvolution analysis. Percentage uptake for each kidney between 1 and 3 minutes after injection of Tc 99m-DTPA was determined and used to indicate glomerular filtration rate. The effect of diuresis was determined by measuring the slope of decrease in activity after IV administration of furosemide. Obstruction was documented by direct inspection of the ureter.

Results

There was a concomitant increase in pTOP, wTOP, pMTT, and wMTT of the kidney with the partially obstructed ureter in all dogs at various times between 2 and 9 days after surgery. Concurrently, renal time-activity curves changed shape. Percentage renal uptake of the affected kidney was decreased in 2 dogs. Response to furosemide injection was inconsistent for kidneys before surgery and for kidneys with obstructed and nonobstructed ureters after surgery.

Conclusions and Clinical Relevance

Scintigraphy may be a useful procedure for the evaluation of renal function in dogs with ureteral obstruction. Induction of diuresis appears to be of little value for differentiating renal function in dogs with obstructed and nonobstructed ureters. (Am J Vet Res 1999;60:1383–1389)
Detection of annexin I and IV and haptoglobin in bronchoalveolar lavage fluid from calves experimentally inoculated with Pasteurella haemolytica
Authors: Katoh Norio , Miyamoto Toru , Nakagawa Hisami , Watanabe Atsushi
Published: January 2024

Objective

To determine whether annexins or haptoglobin could be detected in bronchoalveolar lavage (BAL) fluid specimens obtained from calves experimentally inoculated with Pasteurella haemolytica.

Animals

Twelve 2- to 3-month-old male Holstein calves.

Procedure

Pasteurella haemolytica was inoculated into the right lung lobes of each of 6 calves. Six other calves received vehicle alone and were used as control calves. Specimens of BAL fluid were obtained from 3 control and 3 inoculated calves 1 day after inoculation and from the other calves 2 days after inoculation. The amount of annexins I, II, IV, and VI, and haptoglobin in BAL fluid specimens was examined by use of immunoblot analysis.

Results

Annexins I and IV were detected in BAL fluid specimens obtained from the right lung lobes of each of the inoculated calves, but annexins II and VI were not. Annexin I also was found in BAL fluid specimens obtained from the left lung lobes of each inoculated calf and from left and right lung lobes of the control calves. By comparison, detection of annexin IV was essentially limited to the right lung lobes of inoculated calves. Haptoglobin was detected in some, but not all, BAL fluid specimens from the right lung lobes of inoculated calves, and its detection in BAL fluid was associated with serum proteins such as albumin.

Conclusions and Clinical Relevance

Annexin IV was detected most specifically in response to inoculation of P haemolytica. This protein could be used as a marker for inflammatory pulmonary disease caused by P haemolytica. (Am J Vet Res 1999;60:1390–1395)
Suitability of the cranial portion of the vagina as a site for measurement of intra-abdominal pressure variations in dogs
Authors: Gregory Susan P. , Holt Peter E. , Parkinson Timothy J. , Wathes Christopher M.
Published: January 2024

Objective

To determine whether the cranial portion of the vagina of dogs is a suitable site for measuring intra-abdominal pressure during cystometry.

Animals

16 bitches (8 sexually intact and 8 spayed).

Procedure

2 types of vaginal catheters were used to measure intra-abdominal pressure changes in anesthetized dogs. Catheters were inserted in the rectum and cranial portion of the vagina.

Results

Intra-abdominal pressure variations were detected with greater magnitude in the rectum than the cranial portion of the vagina, regardless of type of catheter used and reproductive status (sexually intact vs spayed) of the dogs.

Conclusions and Clinical Relevance

The rectum was the better site for measuring intra-abdominal pressure changes in female dogs. Measurement of intra-abdominal pressure with concomitant measurement of intravesical pressure to determine detrusor pressure during cystometry in female dogs is more reliably detected from the rectum than the cranial portion of the vagina. (Am J Vet Res 1999;60:1411–1414)