bluuebunny/crossref_metadata_2025 huggingface dataset:
Caudal epidural analgesia induced by xylazine administration in cows
Authors: Jean Guy St. , Skarda Roman T. , Muir William W. , Hoffsis Glen F.
Published: January 2024

Xylazine (0.05 mg/kg of body weight diluted to a 5-ml volume, using 0.9% NaCl) or 5 ml of 0.9% NaCl was administered epidurally into the first caudal intervertebral space (Co1-Co2) in 8 cows (mean ± sd body weight, 583 ± 150 kg). Cows were observed for responses to deep needle pricking of the caudal dermatomes (S3 to Co), sedation, and ataxia. Heart rate, respiratory rate, body temperature, rate of ruminal contractions, coccygeal arterial blood pressure, pHa, blood gas tension (Pao2, Paco2), base excess, total solids concentration, and pcv were determined before and after xylazine administration. Epidurally administered xylazine induced sedation and selective (S3 to Co) analgesia for at least 2 hours. Mild ataxia of hind limbs was observed in 6 cows, but all cows remained standing. Heart rate, respiratory rate, rate of ruminal contractions, arterial blood pressure, Pao2, pcv, and total solids concentration were significantly (P < 0.05) decreased, and Paco2, base excess, and bicarbonate concentration were significantly (P < 0.05) increased after xylazine administration. Epidurally administered 0.9% NaCl did not alter sensory perception to needle pricking and did not affect any of the physiologic variables determined. Although epidural administration of xylazine induced analgesia and sedation in healthy cows, it should be avoided for epidural analgesia in cattle with heart disease, lung disease, and/or gastrointestinal disease because of its potent cardiopulmonary and ruminal depressant effects.
Adaptation of human oscillometric blood pressure monitors for use in dogs
Authors: Hunter James S. , McGrath Charles J. , Thatcher Craig D. , Remillard R. L. , McCain Wilfred C.
Published: January 2024

Two digital oscillometric human blood pressure measuring devices were modified and evaluated as blood pressure monitors in 12 healthy anesthetized dogs. Direct arterial pressures were measured via cannulation of the dorsal pedal artery and were correlated with indirect measurements through an inflatable cuff placed over the dorsal pedal artery below the hock joint of the contralateral limb. Direct and indirect measurements were compared for systolic, diastolic, and calculated mean arterial pressures. Blood pressure ranges between 215/145 mm of Hg and 65/30 mm of Hg were obtained, using combinations of halothane, phenylephrine, calcium, and iv administered fluids. Machine A was found to be insufficient for clinical application, on the basis of correlation coefficients between direct and indirect pressures of 0.78, 0.65, and 0.74 for systolic, diastolic, and mean arterial pressures, respectively. Higher correlation coefficients between direct and indirect pressures (0.77, 0.87, and 0.87, respectively) were obtained with machine B. The results of the study reported here suggest machine B may be an effective blood pressure monitoring device in anesthetized dogs.
Failure of subtotal arytenoidectomy to improve upper airway flow mechanics in exercising Standardbreds with induced laryngeal hemiplegia
Authors: Belknap James K. , Derksen Frederik J. , Nickels Frank A. , Stick John A. , Robinson N. Edward
Published: January 2024

Upper airway flow mechanics and arterial blood gas measurements were used to assess the efficacy of subtotal arytenoidectomy for treatment of induced left laryngeal hemiplegia in horses. Measurements were collected with the horses at rest, and trotting or pacing on a treadmill (6.38° incline) at speeds of 4.2 and 7.0 m/s. Experimental protocols were performed after right common carotid artery exteriorization (baseline), after left recurrent laryngeal neurectomy (lrln), and after left subtotal arytenoidectomy.

At baseline, increasing treadmill speed progressively increased peak inspiratory and expiratory flow (Vimax and Vemax respectively), peak inspiratory and expiratory transupper airway pressure (PuI and PuE, respectively), respiratory frequency (f), tidal volume (VT), minute volume (VE), and heart rate. Inspiratory and expiratory times (TI and TE, respectively) and arterial oxygen tension (Pao2) decreased with increased treadmill speed; inspiratory and expiratory impedance (ZI and ZE, respectively) did not change.

After lrln, Vimax, f, and Pao2 significantly (P < 0.05) decreased at exercise, whereas PuI, TI, and ZI significantly increased. Minute volume decreased at exercise after lrln, but the changes were not significant; lrln had no effect on Vemax PuE, ZE, heart rate, arterial carbon dioxide tension (Paco2), or VT.

Subtotal arytenoidectomy did not improve upper airway flow mechanics or blood gas measurements impaired by laryngeal hemiplegia.
Cell proliferation kinetics in the hair root matrix of dogs with healthy skin and dogs with idiopathic seborrhea
Authors: Kwochka Kenneth W.
Published: January 2024

Cell proliferation kinetic values were established for the hair root matrix of primary anagen follicles of 14 Beagles and 4 Cocker Spaniels with healthy skin and 9 Cocker Spaniels with primary idiopathic seborrhea. Indices were established by intradermal pulse labeling with tritiated thymidine, followed by cutaneous biopsy and autoradiography. The hair root matrix cell labeling index was 23.4 ± 3.5% for Beagles, 24.4 ± 4.0% for healthy Cocker Spaniels, and 24.9 ± 4.3% for seborrheic Cocker Spaniels. These values indicate a rapidly proliferating cell population. Differences among these cell kinetic data for the 3 groups of dogs were not statistically significant. Although significant cell kinetic differences have been reported for other epidermal structures (interfollicular epithelium, upper hair follicle external root sheath, sebaceous glands) in seborrheic Cocker Spaniels, proliferation of hair root matrix cells apparently remains unaffected.
Evoked potentials induced by transcranial stimulation in dogs
Authors: Kraus Karl H. , O’Brien Dennis , Pope Eric R. , Kraus Bonnie Hay
Published: January 2024

Evoked potentials were induced by transcranial stimulation and recovered from the spinal cord, and the radial and sciatic nerves in six dogs. Stimulation was accomplished with an anode placed on the skin over the area of the motor cortex. Evoked potentials were recovered from the thoracic and lumbar spinal cord by electrodes placed transcutaneously in the ligamentum flavum. Evoked potentials were recovered from the radial and sciatic nerves by surgical exposure and electrodes placed in the perineurium. Signals from 100 repetitive stimuli were averaged and analyzed. Waveforms were analyzed for amplitude and latency. Conduction velocities were estimated from wave latencies and distance traveled. The technique allowed recovery of evoked potentials that had similar characteristics among all dogs. Conduction velocities of potentials recovered from the radial and sciatic nerves suggested stimulation of motor pathways; however, the exact origin and pathway of these waves is unknown.
Detection of capsular polysaccharide in milk cows of with natural intramammary infection caused by Staphylococcus aureus
Authors: Sutra Laurent , Poutrel Bernard
Published: January 2024

Detection of capsular polysaccharide (cp) in milk of cows with natural intramammary infection caused by Staphylococcus aureus was attempted. Five quarters of 5 cows harboring S aureus strains that produce type-8 cp were selected. Using an elisa with a monoclonal antibody, type-8 cp was not detected in extracts prepared from fresh milk collected aseptically. By contrast, cp was easily detectable after incubation of infected milk at 38 C for 20 hours. Quantitation of cp in extracts from incubated milk samples by use of elisa indicated a great variation of cp expression by strains. Although an incubation step was necessary to detect cp, results of the study indicate that cp may be expressed in vivo during intramammary infection caused by S aureus.
Biochemical analysis of normal articular cartilage in horses
Authors: Vachon Anne M. , Keeley Fred W. , McIlwraith C. Wayne , Chapman Phillip
Published: January 2024

Articular cartilage specimens from the distal articular surface of 32 radiocarpal bones from 24 2- to 5-year-old horses were analyzed. The total collagen content was determined on the basis of the 4-hydroxyproline content, using a colorimetric method. A method for estimating the proportions of types-I and -II collagen by measuring spectrophotometric densities of specific cyanogen bromide peptide bands from mixtures of types-I and -II collagen on sodium dodecyl sulfate-polyacrylamide gels was used. The cyanogen bromide peptides representative of each collagen types-I and -II were identified. The peptide ratios were then computed for each of several standards of type-I and -II mixtures. A standard curve was derived from the correlation between these ratios and the corresponding proportions of type-II collagen in standard mixtures. Galactosamine and glucosamine content (hexosamines) were measured by ion chromatography. The galactosamine-to-glucosamine ratio, chondroitin sulfate and keratan sulfate values, and total glycosaminoglycan content were derived from the measured hexosamine content.

The total collagen content averaged 556 mg/g (55.6 mg/100 mg) of tissue (dry weight, [dw]). Type-II collagen was the major collagen type in normal articular cartilage specimens. The ratio of the area under the αl (II)CBIO peak to the area under the αl (I)CB 7,8 + αl (II)CB11 peak was a second-order polynomial function of the proportion of type-II collagen in the specimens. The mean galactosamine and glucosamine content were 20.6 mg/g and 7.9 mg/g (dw), respectively. The mean galactosamine-to-glucosamine ratio was 3.74 ± 0.62. Chondroitin sulfate values, keratan sulfate values, and total glycosaminoglycan content were 53.3 ± 4.9 mg/g, 19.9 ± 3.6 mg/g, and 73.2 ± 7.9 mg/g (dw), respectively. There was no significant correlation between the age of the horses and any of the chemical values (P > 0.1). The biochemical composition of articular cartilage in the horse is similar to that of other species.
Purification and comparison of corticosteroid-induced and intestinal isoenzymes of alkaline phosphatase in dogs
Authors: Sanecki Robin K. , Hoffmann Walter E. , Dorner Joseph L. , Kuhlenschmidt Mark S.
Published: January 2024

Corticosteroid-induced alkaline phosphatase (calp) and intestinal alkaline phosphatase (ialp) from dogs were purified to homogeneity, as determined by polyacrylamide gel electrophoresis. Purification involved an uninterrupted system using deae-cellulose, concanavalin Aagarose, and monoclonal antibody affinity columns. The monoclonal antibody was prepared by use of ialp as the antigen. The 2 isoenzymes were compared, using molecular weight determinations, amino acid analyses, peptide mapping, N-terminal sequencing of the first 10 amino acids, carbohydrate analyses, and recognition by anti-ialp)monoclonal antibody. The data indicated that canine ialp and (calp are identical with regard to recognition by monoclonal antibody and N-terminal amino acid sequence, nearly identical in amino acid content and peptide maps, but different in carbohydrate content. It was concluded that (calp is a product of the same gene as ialp and that differences in glycosyl transferase activities between liver and intestines or the presence of glycosidase activities in or around the intestinal mucosae result in the marked difference in carbohydrate content.
Disposition of clorazepate in dogs after single- and multiple-dose oral administration
Authors: Forrester S. Dru , Brown Scott Anthony , Lees George E. , Hartsfield Sandee M.
Published: January 2024

Clorazepate dipotassium was administered orally to 8 healthy dogs at a dosage of 2 mg/kg of body weight, q 12 h, for 21 days. Serum disposition of nordiazepam, the principle metabolite of clorazepate, was determined after the first and last dose of clorazepate. Disposition variables were analyzed by use of model-independent pharmacokinetics by the predictive equations method and the trapezoidal rule method. Complete blood counts, serum chemical analyses, and urinalyses were performed before administration of clorazepate and at 10 and 21 days after administration of clorazepate.

Maximal nordiazepam concentrations ranged from 446 to 1,542 ng/ml (814 ± 334 ng/ml), at 59 to 180 minutes (97.9 ± 42.0 minutes) after a single oral dose of clorazepate. Maximal nordiazepam concentrations ranged from 927 to 1,460 ng/ml (1,308 ± 187.6 ng/ml), at 120 to 239 minutes (153 ± 57.9 minutes) after multiple oral doses of clorazepate. Serum disposition was significantly altered after multiple doses of clorazepate. Using data determined by the predictive equations method, the mean residence time after multiple doses (712 ± 214 minutes) was longer (P < 0.05) than after a single dose (527 ± 95.8 minutes). Oral volume of distribution after multiple doses of clorazepate (1.76 ± 0.647 L/kg) was smaller (P < 0.02) than after a single dose (3.18 ± 1.52 L/kg). Oral clearance after multiple doses of clorazepate (3.09 ± 0.726 ml/min/kg) was less (P < 0.001) than after a single dose (6.54 ± 2.15 ml/min/kg). Absorption half-life after multiple doses (72 minutes) was longer (P < 0.01) than after a single dose (33 minutes). The elimination half-life after a single dose (284 minutes) was not significantly different after multiple doses (355 minutes).

Significant changes (P < 0.05) in serum chemical values after multiple doses of clorazepate included decreased concentrations of albumin, total protein, and calcium and increased concentrations of urea nitrogen and glucose. Serum activities of alkaline phosphatase and alanine transaminase increased after multiple doses of clorazepate. Significant changes (P < 0.05) in the hemogram included increased total wbc count, segmented neutrophils, lymphocytes, and eosinophils. Urine pH after multiple doses (5.88 ± 0.641) was lower (P < 0.01) than after a single dose (7.44 ± 1.29). All changes in laboratory values remained within our reference ranges.

Mild sedation and ataxia developed in only 1 dog after the first dose of clorazepate. These effects were transient and did not redevelop with additional dosing.

An oral clorazepate dosage of 2 mg/kg, q 12 h, maintains serum nordiazepam concentrations considered to be therapeutic in human beings (500 to 1,900 ng/ml).
Immunohistochemical localization of α2-β1-glycoprotein in horses
Authors: Winder N. Christine , Pellegrini A. , von Fellenberg R.
Published: January 2024

Alpha 2-(β1-glycoprotein may be found free in horse serum or complexed with α-1-proteinase inhibitor to form pre-α2-elastase inhibitor. There has been little information published concerning α2-β1-glycoprotein and its possible tissue sources in horses. A peroxidase-antiperoxidase technique was used to identify α2-(β1 -glycoprotein in buffy coat and bone marrow neutrophils of healthy horses. Macrophages and neutrophils in bronchoalveolar lavage samples from clinically normal horses and from horses with chronic pulmonary disease also were positive for α2-(β1-glycoprotein. Alpha 2-β1-glycoprotein was identified in some instances in normal equine hepatocytes of formalin- fixed liver sections. In formalin-fixed lung sections from horses with chronic, small-airway disease and chronic bronchointerstitial pneumonia, α2-β1-glycoprotein was observed in some airway secretions and in macrophages.
Effects of ivermectin and fenbendazole in strategic treatment of gastrointestinal nematode infections in cattle
Authors: Williams J. C. , Knox J. W. , Barras S. A. , Hawkins J. A.
Published: January 2024

Four groups of 18 beef calves each were used to evaluate effects of different treatments on parasite control and weight gains. The investigation extended from November 1986 (weaning) to October 1987. Group-1 calves were treated with ivermectin (200 μg/kg of body weight, SC) at approximately 6-week intervals for a total of 8 treatments; group-2 calves were given the same dosage of ivermectin by the same route of administration as group-1 calves in November, March, and July; group-3 calves were given fenbendazole paste (5 mg/kg, po) at the same times as group-2 calves; and group-4 calves served as untreated controls with provision for ivermectin salvage treatment. All groups grazed on individual pairs of larval-contaminated, 1.6-ha pastures. Highest (P < 0.05) initial worm counts in fall tracer calves were found in group 3 (Ostertagia ostertagi and Trichostrongylus axei adults) and group 4 (O ostertagi and Haemonchus adults). Fecal egg counts of group-1 calves were low throughout the experiment and pasture larval counts remained negligible after July. Egg counts and larval counts of other groups remained higher into summer. Worm counts, including O ostertagi inhibited early fourth-stage larvae (el4), were highest (P < 0.05) in groups-3 and -4 spring tracer calves; numbers of O ostertagi el4 were similarly high in groups 2, 3, and 4; and T axei counts were highest (P < 0.05) in groups-3 and -4 yearlings slaughtered in spring. Liveweights of group-1 calves were greater (P < 0.05) than in other groups from March 2 to October, and by July 2, group-2 calves had a liveweight advantage over group-4 calves. Group- 3 calves had the lowest rate of gain from March to July and mean liveweight of the group was less (P < 0.05) than in all other groups from April to October. Only minimal worm numbers were recovered from groups-1 or -2 calves in October. Large numbers of O ostertagi and T axei were recovered from group-4 calves and O ostertagi from group-3 calves. A few calves in groups 3 and 4, but particularly in group 4, were affected by type-II disease (chronic to acute gastritis caused by maturation and emergence of previously inhibited larvae) from August to October. Final mean liveweights in descending order were 365 kg in group 1, 328 kg in group 2, 316 kg in group and 281 kg in group 3.
Effect of Haemonchus contortus infection on the clearance of antipyrine, sulfobromophthalein, chloramphenicol, and sulfathiazole in lambs
Authors: Kawalek J. C. , Fetterer R. H.
Published: January 2024

A study was made to determine the effect of Haemonchus contortus parasitic infection in lambs on the clearance of several IV administered drugs. Clearance of sulfobromophthalein or sulfathiazole from the plasma of lambs was unaffected by infection with H contortus. Clearance of antipyrine was enhanced by the infection, and thiabendazole treatment did not alter this effect. Clearance of chloramphenicol (cap), administered as the succinate ester (caps), was not changed by the infection, but it was increased after treatment with thiabendazole. Changes in the mean body residence time and initial plasma concentration of caps and cap after treatment with thiabendazole indicate that hydrolysis of caps to cap was reduced. High concentrations of caps apparently enhanced its own elimination directly rather than via the expected sequence involving hydrolysis, glucuronidation, and excretion of cap-glucuronide.

Enhanced clearance of antipyrine following infection of lambs with H contortus can be explained in at least 2 ways. First, it is possible that the lambs did not have mature amounts of hepatic drug metabolizing enzyme activity as reported by other investigators, which may be explained by breed differences or animal husbandry practices. Second, infection of lambs by H contortus may have triggered an inductive response in hepatic cytochrome P- 450-mediated activities, which might result via a generalized enhancement in hepatic protein synthesis associated with the physiologic response to replace plasma proteins and other blood components lost through gastrointestinal hemorrhage caused by the active feeding of adult worms. Other phase-II reactions such as acetylation, glucuronidation, and glutathione-S-transferase apparently were not affected.
In vitro and in vivo evaluation of effects of a heptanoyl tripeptide, FK-565, on porcine macrophage and lymphocyte function
Authors: Chitko C. G. , Chapes S. K. , Thaler R. C. , Nelssen J. L. , Anderson G. A. , Clough E. R. , Blecha F.
Published: January 2024

A series of experiments was performed in vitro and in vivo to determine the influence of FK-565, a heptanoyl tripeptide, on lymphocyte and macrophage function in swine. Compared with values for control cultures, mitogen-stimulated lymphocyte blastogenesis and interleukin-2 production were unaffected in cells preincubated with 0.1, 1.0, and 10.0 μg of FK-565/ml. Natural killer cell activity was increased by preincubation with 1.0 μg of FK-565/ml; however, this increase was not statistically significant. In vitro treatment of porcine alveolar macrophages with FK-565 did not enhance cytolytic activity or bactericidal activity. In in vivo experiments, FK-565 given orally to pigs at concentrations of 6 or 60 μg·kg-1·d-1 for 5 days did not affect lymphocyte blastogenesis, interleukin-2 production, or alveolar macrophage bactericidal activity. A trend toward increased natural killer cell activity was evident in pigs treated with FK-565. In contrast, pigs treated with 6 μg·kg-1·d-1 had significantly (P < 0.01) decreased alveolar macrophage cytolytic activity. These data indicate that at the dosages tested, FK-565 is not a suitable immunomodulator for enhancement of nonspecific immunity in swine.
Comparison of genitoanal and bulbospongiosus reflexes and measurement of penile nerve conduction velocity in cats
Authors: Cook James R. , Oliver John E. , Purinton Paul T.
Published: January 2024

The bulbospongiosus reflex, genitoanal reflex, and nerve conduction velocity of the dorsal nerve of the penis were evaluated in cats. Seven adult sexually intact or castrated male mixed-breed cats underwent surgical isolation of the bulbospongiosus (analagous to bulbocavernosus) branch, anal branch, and distal trunk of the pudendal nerve. The bulbospongiosus and genitoanal reflexes were recorded from the bulbospongiosus and anal branches, respectively, by electrical stimulation, in turn, of the distal pudendal trunk and the penis itself. Nerve conduction velocity of the dorsal nerve of the penis was calculated by measuring response latency differences in the anal branch after stimulation of 2 sites on the extruded penis.

The bulbospongiosus reflex had response latencies of 8.1 to 10.3 ms (distal trunk stimulation) and 11.0 to 13.0 ms (penile stimulation). The genitoanal reflex had latencies of 8.1 to 10.5 ms (distal trunk stimulation) and 11.2 to 13.2 ms (penile stimulation). Response amplitudes diminished at stimulus rates of 5 to 10 Hz; responses were abolished at rates of 12 to 15 Hz, suggesting that the reflexes are polysynaptic. There was no significant difference between latency values for the bulbospongiosus and genitoanal reflexes.

Mean ± sd nerve conduction velocity in the dorsal nerve of the penis was calculated to be 3.8 ± 0.34 m/s, which was considerably slower than that found in human beings. This may represent technical difficulties in performing the test in cats, but could also indicate a difference between cats and human beings in the predominant population of cutaneous sensory fiber types of the penis.
Relationship between virulence and adherence of various enterotoxigenic Escherichia coli strains to isolated intestinal epithelial cells from Chinese Meishan and European Large White pigs
Authors: Bertin Anne M. , Duchet-Suchaux Marion F.
Published: January 2024

In vitro adherence to intestinal epithelial cells by enterotoxigenic Escherichia coli strains bearing K88, K99, F41, or 987P adhesins and of their variants not bearing adhesins (K88-, K99-, or F41-) was investigated in European Large White and Chinese Meishan pigs. Possible relationship between adherence and virulence was also examined. The K88-positive (K88+ ) strain strongly adhered to intestinal epithelial cells from 26 of 28 Large White pigs. This strain had previously been found to be highly virulent for Large White pigs. The only surviving pig was of nonadherent phenotype, and cells from 4 dehydrated moribund pigs had strong adherence. By contrast, the same K88+ strain found previously to have little pathogenicity for Meishan pigs adhered with variable intensity to cells from 17 of 23 Meishan pigs; correlation was not evident between adherence and virulence. The K99+F41+ strain of porcine origin and the F41+ strain generally adhered strongly to cells from 24 and 23 Meishan pigs, respectively, and to cells from 25 of 26 Large White pigs. Correlation was not found between adherence and virulence for the 2 strains. A K99+F41+ strain of bovine origin adhered to cells from 20 of 22 Meishan and 22 of 23 Large White pigs, and a K99-F41+ variant adhered to cells from 19 of 23 Meishan and 23 of 24 Large White pigs. The adhesin-negative variants never adhered to intestinal epithelial cells. Strain 987 known not to readily produce 987P adhesin after in vitro growth never adhered to cells during the test.

Results indicated that K88, K99, and F41 adhesins were responsible for in vitro adherence and, except for the K88+ strain in Large White pigs, adherent phenotype was not a sufficient condition to make a pig susceptible to enterotoxigenic E coli. The contribution of physiologic factors and their genetic origin to the degree of resistance of the individual is not yet completely understood for every enterotoxigenic E coli strain and breed of pig.
Postnatal development of the visual-evoked potential in dogs
Authors: Strain George M. , Jackson Rose M. , Tedford Bruce L.
Published: January 2024

Recordings of visual-evoked potentials that were induced by flashes of white light were obtained from 13 Beagle pups to document the development of the response from age 7 to 100 days. Responses were recorded between needle electrodes placed on the nuchal crest and the interorbital line, with ground at the vertex. Five alternating positive (P) and negative (N) peaks were observed in most visual-evoked potentials: P1, P2, N2, and P3. Responses were recorded from 2 pups prior to opening of the eyelids. Recordings were performed without sedation or dark adaptation. Peak latencies were essentially mature (equal to those of adult dogs) by day 11 for P1, and by day 38 for N1 and P2. The latencies to N2 and P3 did not reach adult values by day 100, but did reach plateau values by day 43. The P1-N1 amplitude measurements reached mature levels by day 14, whereas N1-P2 amplitudes were mature by day 32. The P2-N2 and N2-P3 amplitudes reached plateaus that greatly exceeded adult amplitudes by days 50 and 58, respectively. Maturation of visual-evoked potential responses paralleled reported morphologic development of the visual cortex. All of the measured latency and amplitude values had significant (P ≤ 0.004) linear regression lines of latency vs age or amplitude vs age.
Establishment of dose-response relationships in BALB/c mice, using Brucella cell surface protein and lipopolysaccharide
Authors: Pugh George W. , Tabatabai Louisa B. , Phillips Marshall , McDonald Timothy J.
Published: January 2024

A study was conducted to determine the immune (increased antibody) and protective (reduced colony-forming units) responses induced in mice by a: (i) single vaccinal inoculation, using various concentrations of Brucella cell surface protein (bcsp) or lipopolysaccharide (lps); (ii) primary inoculation, using various concentrations of bcsp, followed by a secondary inoculation, using a standard concentration of bcsp; and (iii) primary inoculation, using 1 concentration of bcsp or lps, followed by a secondary inoculation, using various concentrations of bcsp or lps. Four weeks after the primary inoculation, mice were challenge exposed with approximately 1 × 104 colony-forming units of Brucella abortus strain 2308 and all mice were euthanatized at 6 weeks. Reduced splenic weights and reduced colony-forming units in the spleens of vaccinated mice, compared with nonvaccinated mice, were the criteria of protection. Increase in serum IgM and IgG was defined as immunity.

Both bcsp and lps induced protective and immune responses that were proportional to the dose given up to an optimal limit. However, concentrations higher than optimal decreased the protective and immune responses. This was true for mice given either 1 or 2 vaccinal inoculations. Enhanced secondary protective responses were seen only when suboptimal doses were used in the primary inoculation. Excessive or optimal doses in the secondary inoculations prevented or obscured the protectiveness and immunity by primary inoculations. The protective effects appeared to be additive when suboptimal doses were used in the primary and secondary inoculations. Inoculation of subimmunogenic doses induced a relative reduction in the antibody concentration after challenge exposure, compared with nonvaccinated mice.

The overall results indicated that the protective responses induced by bcsp were probably attributable to lps. The results also indicated a linear increase in protection and immune response corresponding to increasing doses up to an optimal dose, and this stoichiometric optimum may be achieved by the use of 1 or more vaccinal inoculations. However, once this optimum was obtained, additional amounts of bcsp or lps cause perturbation of both the protective and serologic responses.
Effect of method of seminal collection on the retrograde flow of spermatozoa into the urinary bladder of rams
Authors: Pineda M. H. , Dooley M. P.
Published: January 2024

The effects of method of seminal collection and a diuretic on retrograde flow of spermatozoa into the urinary bladder of rams were examined. In experiment 1, semen and urine were collected from 8 rams during the non-breeding season. Prior to seminal collection, all rams were given furosemide and a sample of urine was obtained during micturition. Semen was then collected from each ram with an artificial vagina or by electroejaculation in alternate weeks for 4 weeks, and the urine released during the first postseminal collection micturition was collected in 4 consecutive samples. The volume of electroejaculates was larger (P < 0.0001) than the volume of ejaculates, but the total number of spermatozoa in the electroejaculate or in the ejaculate were not different (P > 0.1). Urine obtained before seminal collection was azoospermic or contained few, nonmotile spermatozoa (mean ± sd = 0.053 ± 0.114 × 106/ml). The adjusted spermatozoal concentration (mean ± sd = 1.630 ± 2.258 × 106/ml) in the urine collected after seminal collection was 31 times higher (P < 0.0001) and there were motile spermatozoa in most (97%) of the samples. The spermatozoal concentration in sequential samples of urine was not different (P > 0.1) between samples and was not affected (P > 0.1) by the method of seminal collection. There was a trend, approaching significance (P = 0.052), for an effect of method of seminal collection on the percentage of retrograde flow. Retrograde flow ranged from 0.21 to 19.38% when semen was collected with an artificial vagina and from 0.03 to 94.60% when semen was collected by electroejaculation and varied (P = 0.02) among rams within the 2 methods of seminal collection. In experiment 2, the 8 rams used in experiment 1 were given injections of 0.9% physiologic saline solution or furosemide in alternate weeks prior to seminal collection with an artificial vagina. Furosemide increased (P = 0.009) the volume of urine voided during the first postejaculation micturition, but did not influence (P > 0.1) the time from exposure of rams to the teaser to ejaculation, seminal characteristics, number of spermatozoa in the urine, or the percentage of retrograde flow. There was a trend (P < 0.1) for more rams to have motile spermatozoa in the postejaculation urine after treatment with furosemide. Administration of furosemide prior to seminal collection facilitates the noninvasive collection of pre- and postejaculation samples of urine for the determination of retrograde flow.
Use of fine-wire electrodes for electromyographic evaluation of the external urethral sphincter during urethral pressure profilometry in male cats
Authors: Sackman Jill E. , Sims Michael H.
Published: January 2024

Evaluation of urethral pressure profilometry (upp) with simultaneous fine-wire electromyography of the external urethral sphincter (eus) was conducted in 11 healthy adult male cats sedated with xylazine and ketamine. A 3.5-F urethral catheter with a closed end and two 1-mm sideports was infused with sterile 0.9% NaCl solution at a rate of 2 to 3 ml/min. A fine-wire electromyographic (emg) electrode was placed percutaneously into or near the external urethral sphincter prior to the onset of the upp. The maximal urethral pressure achieved and functional profile length were recorded from upp. Setting both catheter withdrawal rate and paper speed at 5 mm/s enabled the measurement of actual urethral length directly from upp. Sphincter emg activity was rated as slight ( + ), moderate (+ +), or intense (+ + +). All recordings were replicated once during each trial for 8 cats and trials were replicated 5 to 7 days later in 4 cats.

Before catheterization, emg activity of the external urethral sphincter was rated slight ( + ), whereas intense (+ + +) activity accompanied insertion. The activity evoked by movement of the catheter subsided, but intense emg activity of the external urethral sphincter was recorded from onset to completion of catheter withdrawal in all cats in both trials. The mean maximal urethral pressure was 93.1 ± 13.29 cm H20. The mean function urethral length was 8.1 ± 0.93 cm. Maximal urethral pressure or function profile length did not differ significantly between recordings within trials or between trials. Simultaneous recording of emg activity and upp of the external urethral sphincter was shown to be a simple, noninvasive technique for assessing neuromuscular and anatomic urethral function.
Effect of oral administration of prednisolone on thyroid function in dogs
Authors: Torres Sheila M. F. , McKeever Patrick J. , Johnston Shirley D.
Published: January 2024

To determine the effect of oral administration of prednisolone on thyroid function, 12 healthy Beagles were given 1.1 mg of prednisolone/kg of body weight every 12 hours for 22 days after 8 days of diagnostic testing of the dogs before treatment with prednisolone. Thyroid-stimulating hormone (tsh) and thyrotropin-releasing hormone (trh) response tests were performed before treatment (days 1 and 8 of the study) and during treatment (days 21 and 28 of the study). Blood samples were collected daily at 8 am and 2 and 8 pm to rule out normal daily hormone fluctuations as the cause of a potential decrease in serum triodothyronine (T3), thyroxine (T4), and free T4 (fT4) concentrations. Serum T3, T4, and fT4 concentrations before treatment and 1 day and 21 days after the first prednisolone dose were compared by analyses of variance. Post-tsh and -trh serum T3 and T4 concentrations before and during treatment were compared, using the Student t test for paired data. Oral administration of prednisolone significantly (P < 0.005) decreased serum T3, T4, and fT4 concentrations in the 8 am and 2 and 8 pm samples obtained 1 day and 21 days after the first prednisolone dose. Serum T4 and fT4 concentrations in 8 am and 2 pm samples were significantly (P < 0.05) lower 21 days after the first prednisolone dose than they were at 1 day after the first dose. Before treatment, serum T4 concentration in the 2 pm samples was significantly (P < 0.05) higher than serum T4 concentration in 8 am and 8 pm samples. Oral administration of prednisolone significantly (P < 0.01) decreased serum T3 and T4 concentrations 6 hours after tsh and trh injections. Significant difference in the mean incremental change in serum T3 and T4 concentrations was not observed when comparing before- and during-prednisolone treatment values for the trh response test. However, for the tsh response test, the mean incremental changes in serum T3 and T4 concentrations were significantly (P < 0.01) lower during prednisolone treatment. Despite the decreased tsh response incremental change in serum T4 concentration during oral treatment with prednisolone, the lowest value observed fell within the before-treatment range. In addition, during treatment, baseline serum T3 and T4 concentrations after tsh administration increased, on average, 3.7 and 8.4 times, respectively.
Tumor necrosis factor activity in the circulation of horses given endotoxin
Authors: MacKay R. J. , Merritt A. M. , Zertuche J.-M. , Whittington M. , Skelley L. A.
Published: January 2024

Serum and plasma from horses injected with endotoxin was examined for cytotoxic activity. Each of the cell lines, L929 and WEHI 164 clone 13, was sensitive to the cytotoxic effects of equine serum; however, a precipitation artifact caused by the use of isopropanol in the WEHI assay limited the use of this assay to samples containing <2 mg of protein/ml. In foals treated with a sublethal iv bolus of 5 μg of lipopolysaccharide (LPS)/kg and in adult horses given a low-dose continuous infusion of LPS (30 ng/ kg/h for 4 hours), cytotoxic activity was detected in all serum or plasma samples taken between 30 minutes and 4 hours after LPS infusion began. In horses given either continuous or bolus lps infusions, circulating cytotoxic activity peaked at 1 to 2 hours before decreasing sharply. The onset of pyrexia after lps infusion coincided with the appearance of circulating cytotoxic activity, but the temperature remained high, even after cytotoxic activity disappeared. Treatment of horses with flunixin meglumine (1 mg/kg) appeared to blunt the pyrexic effect of low-dose continuous LPS infusion, but had no significant effect on circulating cytotoxic activity. Incubation of serum samples with an antibody raised against a portion of human tumor necrosis factor (tnf) resulted in the removal of >90% of serum cytotoxicity, suggesting strongly that the cytotoxic activity was attributable to tnf. These findings are consistent with the hypothesis that tnf is an early acting mediator of the effects of endotoxin in the horse.
Potential attachment area of the fourth maxillary premolar in dogs
Authors: Smith Mark M. , Massoudi Lisa M.
Published: January 2024

Tooth root and root trunk surface area measurements were made on 20 permanent fourth maxillary premolar (P4) teeth randomly harvested from canine cadaver specimens. Mean root surface area for all 20 teeth was 562.8 ± 124.9 mm2. Cumulative surface areas of the mesiopalatal, mesiobuccal, and distal roots were 113.8 ± 29.0 mm2, 138.5 ± 34.6 mm2, and 180.8 ± 39.9 mm2, respectively. The mesial root trunk and distal root trunk surface areas were 60.0 ± 17.5 mm2 and 72.1 ± 33.2 mm2, respectively. There was not a significant difference between the root surface area of the mesial root trunk and distal root trunk; however, all other root surface area measurements were significantly different (P < 0.01). Cumulative individual root surface area (distal root + mesiobuccal root + mesiopalatal root) was 76% of total root surface area. The distal root surface area contributed most to total root surface area (32.1%) and cumulative individual root surface area (41.7%). Observation of the linear variation of percentage of root surface area revealed 40.8% of the total root surface area to be in the portion located between 5 and 9 mm apical to the most coronal aspect of the cementoenamel junction. The mesiobuccal root and distal root were cylindrical compared with the flattened, concave shape of the mesiopalatal root.
Use of flow cytometry for determination of differential leukocyte counts in bovine blood
Authors: Jain Nemi C. , Paape Max J. , Miller Robert H.
Published: January 2024

A flow cytometric method was developed to perform differential leukocyte counts on bovine blood. Blood specimens from 50 healthy Holstein cows were analyzed by use of a flow cytometer. The method entailed diluting blood with phosphate-buffered, hypotonic saline solution containing acridine orange, and performing a step-wise, 3-parameter analysis on the bases of cell size, cellular granularity, and granulocyte fluorescence. Initially, proportions of monocytes, granulocytes, and lymphocytes were determined by creating appropriate windows on dot plots of cell size (determined by forward light scatter) vs cellular granularity (determined by the logarithm of side light scatter). Eosinophils were resolved by analysis of granulocytes as dot plots of logarithms of green vs red fluorescence ascribed to acridine orange. Proportions of eosinophils and neutrophils were computed from data so generated. Microclumps of platelets spuriously affected counts of some granulocytes, particularly eosinophils.

Differential leukocyte counts determined by flow cytometry generally compared favorably with those obtained by use of the conventional microscopic method, using Wright-stained blood films. Mean neutrophil and eosinophil counts determined by the 2 methods did not differ significantly, but lymphocyte counts determined by flow cytometry were significantly higher than those determined by microscopy (P < 0.01). Correlation coefficients for counts of neutrophils, eosinophils, and lymphocytes determined by the 2 methods ranged from 0.519 to 0.833. Correlation between monocyte counts was low (r = 0.147), although mean monocyte counts determined by the 2 methods did not differ significantly. Total leukocyte counts determined by flow cytometry were significantly lower (P < 0.01) than counts determined by use of an automated cell counter; correlation between the 2 counts was low (r = 0.350).
Comparative studies on bioavailability and tissue uptake of two intraruminally or intraperitoneally administered esters of α-tocopherol in sheep
Authors: Hidiroglou M. , Charmley E.
Published: January 2024

An experiment was conducted to compare the bioavailability of dl-α-tocopherol acetate (ta) with that of dl-α-tocopherol nicotinate (tn) when administered to sheep, as a single dose, either into the rumen or the peritoneal cavity. A total of 16 sheep were used in a factorial design, with 4 sheep/treatment at the interaction level. In addition, 5 sheep that received no supplemental α-tocopherol, were euthanatized at the end of the trial to provide baseline data for tissue α-tocopherol concentrations. Curves were fitted to the plasma α-tocopherol concentration values, taken over 180 hours after administration of the esters. Availability of ta was greater than tn, as evidenced by the significantly higher curve parameter values (P < 0.05) and tissue concentrations (P < 0.05). Route of administration had a marked effect on availability of ta (P < 0.001), but not of tn.
Experimental establishment of persistent infection in swine with a zoonotic strain of Salmonella newport
Authors: Wood Richard L. , Rose Rebecca , Coe Nancy E. , Ferris Kathleen E.
Published: January 2024

An experiment was conducted to determine whether a persistent Salmonella newport infection could be established in swine, to determine duration of shedding and distribution of the organism in internal organs, and to determine whether changes occurred in antimicrobial susceptibility or plasmid profile of the organism during the course of long-term infection. Naturally farrowed Salmonella-free pigs (n = 22) were orally exposed to a multiply antimicrobial-resistant zoonotic strain of S newport when they were 7 weeks old. Tonsillar and rectal swab specimens were examined bacteriologically for S newport during the first week after exposure, then weekly for 7 weeks. Fecal samples were likewise examined weekly or every 2 weeks for 28 weeks after exposure. Necropsies of 2 or 3 randomly selected pigs were conducted at 2, 4, 8, 12, 16, 20, 24, and 28 weeks after exposure. A total of 45 specimens/pig representing the following internal organs or tissues were examined bacteriologically for S newport: liver, spleen, kidney, gallbladder, heart, heart blood, lung, stomach, and tonsils; segments of the intestinal tract with corresponding lymph nodes; and lymph nodes from lymphocenters of the head and neck, thoracic cavity, thoracic limbs, abdominal viscera, and abdominal wall. Exposure to S newport induced a mild and transient clinical response. The organism was recovered from 97% of tonsillar swab specimens and 89% of rectal swab specimens collected during 7 weeks after exposure and from 98% of fecal samples collected during 28 weeks after exposure. At necropsy, S newport was recovered most frequently from tonsils (86.4%), followed by segments of the intestinal tract from ileum to rectum (81.8% recovery from cecal contents), and from mandibular (68.2%), jejunal (50%), and ileocolic (45.5%) lymph nodes. Sporadic recoveries of the organism were made from other lymph nodes and from gallbladder, stomach, kidney, spleen, liver, and heart, varying from 2 to 20 weeks after exposure. The cranial portion of jejunum, medial iliac lymph nodes, dorsal superficial cervical lymph node, and heart blood of all pigs were culture-negative. Of 26 representative isolates of S newport recovered from body organs or feces during 28 weeks after exposure, 4 (15.4%) underwent changes in antimicrobial susceptibility pattern. Changes in plasmid profile of the organism were not detected during longterm infection of swine.
Effects of amiodarone on myocardial performance in normal canine hearts and canine hearts with infarcts
Authors: Ware Wendy A. , Muir William W. , Swanson Clifford
Published: January 2024

The effects of iv administered amiodarone, a class-III antiarrhythmic agent, on myocardial contractility, early myocardial relaxation, and hemodynamic variables were evaluated in normal canine hearts and those with infarcts. In the normal canine heart, amiodarone had important, but relatively mild, depressant effects on left ventricular contractility (assessed by maximal positive first derivative of left ventricular pressure (+ dP/dtmax) and maximal elastance (Emax)) and heart rate when given iv at a dose of 10 mg/kg of body weight. An effect on contractility or active relaxation (assessed by maximal negative first derivative of left ventricular pressure (— dP/dtmax) and the time constant of isovolumic pressure decrease) was not identified with smaller doses. Myocardial infarction itself caused a predictable and marked depressant effect on myocardial contractility, as indicated by decreases in + dP/dtmax, ejection fraction, Emax, and — dP/dtmax, and elevation in end diastolic pressure. Additional depressive effects on contractility and active relaxation resulted when 10 mg of amiodarone/kg was administered to dogs with myocardial infarction and these effects were sufficient to worsen acute myocardial infarction-induced heart failure. Significant changes attributable to heart rate alone could not be identified. On the basis of our findings, we suggest that amiodarone administered iv should be used with caution in dogs with compromised ventricular function.
Effect of milbemycin oxime against Ancylostorna caninum in dogs with naturally acquired infection
Authors: Wade C. G. , Mercer S. H. , Hepler D. I. , Craig T. M.
Published: January 2024

Twenty-six mixed-breed (14 males, 12 females) dogs were used in a double-blind study to evaluate the effect of milbemycin oxime against naturally acquired infection with Ancylostorna caninum. Dogs were ranked and paired, on the basis of number of hookworm eggs/g of feces, and treatment was randomly assigned. Each dog was given either the study drug or placebo (1 tablet/11.4 kg [0.5 mg/ kg] of body weight). Eggs per gram of feces enumeration was done on days 3 and 7 after treatment, and dogs were euthanatized on day 7.

On day 3, 5 of the 13 dogs in the milbemycin-treated group had hookworm eggs in the feces (results of the McMaster test). In these dogs, mean number of eggs per gram of feces had decreased markedly (from 5,289 to 452) and, by day 7, was 114. At necropsy, 16 A caninum adults were recovered from 2 of the milbemycin-treated dogs. On day 3, 12 of the 13 dogs in the placebo-treated group had hookworm eggs in the feces. Mean number of eggs per gram of feces in these dogs decreased slightly (from 5,243 to 2,646), but did not decrease further by day 7. A mean number of 54.4 A caninum adults was recovered from 12 of the 13 placebo-treated dogs at necropsy. Milbemycin oxime had 97.8% efficacy against A caninum. Results also indicated that milbemycin oxime may be effective against Trichuris vulpis, but not against Dipylidium caninum.