bluuebunny/crossref_metadata_2025 huggingface dataset:
Mitogen and Mixed Lymphocyte Culture Responses of Isolated Bovine Lymphocyte Subpopulations
Authors: Belden E. Lee , Strelkauskas Anthony J.
Published: February 2025

Examinations were made of the mitogen and mixed lymphocyte culture (mlc) responses of subpopulations of bovine lymphocytes isolated by density sedimentation following sequential E-rosetting with aminoethylisothiouronium bromide- and neuraminidase-treated sheep erythrocytes (Eaet, En). These procedures consistently separated 3 populations of E-rosetting T cells from a 4th population of non-E-rosetting cells (B and null cells). The isolated B and null cell population did not respond to phytohemagglutinin, concanavalin A, or pokeweed mitogen and responded minimally in mixed lymphocyte culture. Conversely, isolated T cells responded well to each of these stimuli. Moreover, differences in responsiveness were found among the 3 T-cell populations isolated by differential rosetting. T cells with receptors for both Eaet and En rosette formation were the most responsive to the mitogens used and demonstrated maximum activity in mlc. T cells with only Eaet receptors had equivalent activity in mlc and less activity in response to mitogens. Cells with only En receptors were the least active T-cell population in these assays. The different reactivities of these T-cell populations in lymphoproliferative assays indicated that they represent distinct subsets of bovine T cells.
Effect of Histamine and Prostaglandin E2 on Gastric Blood Flow in Swine
Authors: Zamora C. S. , Reddy V. K. , Johnson P. , Gallagher L.
Published: February 2025

Gastric blood flow was measured by the radioactive microspheres entrapment technique following the iv infusions of saline solution, histamine, or prostaglandin E2 and histamine to young pigs. Pigs treated with histamine (2 μg/kg/minute for 60 minutes) had significantly higher blood flow to the gastric mucosa (P < 0.025), particularly to the region of the proper gastric (fundic) glands (P < 0.01), than did the saline-treated pigs. When prostaglandin E2 (1μg/kg/minute for 60 minutes) was infused simultaneously with histamine, there was a slight, but not significant, decrease (P < 0.10) in mucosal blood flow to the region of the proper gastric glands. Analysis of the percentage distribution of blood flow indicated that the increase in blood flow to the region of the proper gastric glands after histamine infusion may be due to a redistribution of blood flow from the cardiac gland region.
Occurrence and Evaluation of a Reflex-Evoked Muscle Potential (H Reflex) in the Normal Dog
Authors: Sims Michael H. , Selcer Robert R.
Published: February 2025

Reflex-evoked muscle potentials (remp) were recorded in 13 adult dogs and 6 pups at 1, 4, and 12 weeks of age. The remp was recorded in a forelimb interosseous muscle in response to stimulation of the ulnar nerve at a proximal (elbow) and distal (radiocarpal joint) location. The reflex potential appeared after the direct-evoked muscle potential (demp) and its latency increased (in contradistinction to that of the demp) when the point of stimulation was moved from a proximal to a distal site. The threshold for the reflex potential was low and in most instances, lower than that for the demp. As stimulus intensity was increased above remp threshold, the amplitude of the reflex potential increased to a maximum which most often occurred before attainment of demp maximum amplitude. With stimuli supramaximal to the remp, there was a slight decrease in amplitude of the reflex potential, but it remained, even at intensities supramaximal for the demp. In none of the dogs and pups was the remp threshold at a level maximal or supramaximal for the demp.

The latency, duration, and amplitude for both remp and demp were recorded, and recruitment curves were plotted for each type of potential in adults. Motor and sensory nerve conduction velocities (mncv and sncv) were calculated based on demp and remp latencies, respectively. The sncv was not different from mncv in pups between 1 and 12 weeks of age, nor was it lower (mean ± sem = 58.3 ± 3.9 m/s) than mncv (63.1 ± 2.5 m/s) in adults.

An estimation of the lower motor neuron population participating in the remp (proximal site) in adult dogs and pups was calculated, based on mean remp/demp values. The mean for the adult dogs was 7.9 ± 1.6%. In the pups, the values were 31.5 ± 11.3%, 1.0 ± 0.5, and 2.6 ± 1.4% at 1, 4, and 12 weeks, respectively.

After acute unilateral deafferentation of spinal nerves C-5 through T-3 in 4 adult dogs, the remp could no longer be recorded ipsilaterally, whereas the demp was unaltered. Thus, the remp was not only shown to be spinal in origin, but reflexive as well. Additional observations comply with criteria which indicate that this reflex is the equivalent in most ways to the H reflex in persons and therefore probably is monosynaptic.
Serum Biochemical Changes in Dogs with Experimental Leptospira interrogans Serovar icterohaemorrhagiae Infection
Authors: Navarro Carlos E. Kantek , Kociba Gary J. , Kowalski Joseph J.
Published: February 2025

Inoculation of 2 groups of dogs with 1 x 109 and 4 x 109 Leptospira interrogans serovar icterohaemorrhagiae produced disease varying from transient fever to uremia and death. Clinical signs of disease in the severely affected dogs were fever, dehydration, depression, and icterus. Laboratory changes in serum of infected dogs included increased urea nitrogen, creatinine, phosphorus, alkaline phosphatase, total bilirubin, aspartate aminotransferase, and alanine aminotransferase. Chloride concentration decreased in the serum of dogs with severe disease. The icterus in the infected dogs did not appear to be related to hemolytic anemia.
Collateral Ligaments of the Canine Stifle Joint: Anatomic and Functional Analysis
Authors: Vasseur Philip B. , Arnoczky Steven P.
Published: February 2025

The anatomic features and functions of the collateral ligaments of the canine stifle joint were investigated, using cadaver specimens. The structure of the collateral ligaments was examined by dissection, with attention given to the spatial relationships existing between the collateral ligaments and their neighboring structures, such as the menisci and joint capsule. The relative tension of the ligaments was determined by identifying the points of attachment with lead markers and taking a series of radiographs of the joint throughout its range of motion. The distance between the points was measured, and the change in length was determined as a function of joint position. Measurements of internal and external rotation, varus angulation, and valgus angulation were made before and after severance of one or both ligaments. The medial collateral ligament was taut in extension, with only the caudal portion of the ligament becoming lax in flexion. The lateral collateral ligament was also taut in extension; however, its entire bulk became lax as the joint was flexed. In extension, the ligaments were primary restraints preventing varus and valgus angulation, and they functioned to limit internal and external rotation of the tibia. In flexion, the cranial portion of the medial collateral ligament remained taut and prevented external rotation of the tibia, whereas the relaxation of the lateral collateral ligament allowed the tibia to rotate internally, with further rotation limited by the cruciate ligaments.
Distribution of Antibodies to Rotavirus in Serum and Lacteal Secretions of Naturally Infected Swine and Their Suckling Pigs
Authors: Hess R. Guenter , Bachmann Peter A.
Published: February 2025

Rotavirus antibodies were demonstrated in lacteal secretions and sera of 20 parturient sows and in sera of their newborn by an enzyme-linked immunosorbent assay blocking technique, using bovine rotavirus cell culture antigen and monospecific antibody to bovine rotavirus.

Antibodies to rotavirus occur in the 3 immunoglobulin (Ig) classes IgM, IgA, and IgG in lacteal secretions. High and long-persisting antibody activity was mainly associated with the IgA class. The IgM and IgG decreased to undetectable concentrations in most sows during the 14-day investigation period. Serum antibodies of newborn pigs nursing their dams also decreased rapidly during this time.

The heterologous enzyme-linked immunosorbent assay blocking technique was a reliable and rapid procedure for the demonstration of rotavirus antibodies.
Ivermectin: Controlled Test of Anthelmintic Activity in Dairy Calves with Emphasis on Dictyocaulus viviparus
Authors: Lyons E. T. , Tolliver S. C. , Drudge J. H. , LaBore D. E.
Published: February 2025

Twelve dairy calves, naturally infected with lungworms and gastrointestinal parasites, were selected for a controlled test with single doses of ivermectin, administered subcutaneously, at the dose rate of 200 μg/kg. Specific interest was on efficacy of ivermectin against lungworms (Dictyocaulus viviparus), with ancillary interest directed on abomasal parasites. Ivermectin was administered to 6 calves, and the vehicle only, to 6 calves. At necropsy, 7 days after treatment, lungworms were not recovered from any of the treated calves; nontreated calves, given the vehicle only, were infected with 1 to 46 lungworms each.

Removal efficacy against adult Ostertagia ostertagi was 99%. Fourth-stage Ostertagia spp and Trichostrongylus spp and mature Trichostrongylus axei, present in low numbers, were all removed. The fecal egg count for gastrointestinal parasites indicated all eggs, except for a few Nematodirus eggs, were cleared from treated calves. One treated calf showed signs of irritation of the neck at injection site for a short time after treatment and 1 treated calf had a slight indurated area at injection site at necropsy.
Efficacy of Levamisole Against Abomasal Nematodes and Lungworms in Dairy Calves: Preliminary Tests Indicating Reduced Activity for Ostertagia ostertagi
Authors: Lyons E. T. , Tolliver S. C. , Drudge J. H. , Hemken R. W. , Button F. S.
Published: February 2025

Dairy calves (n = 18) were used in controlled tests to evaluate activity of levamisole against abomasal nematodes and lungworms. Two formulations of levamisole, injectable (experiment A) and bolus (experiment B), were given in single doses at rates of 6 mg/kg of body weight and 5.4 to 10.2 mg/kg (5.4, 7.6, 8.0, 8.8, or 10.2 mg/kg), respectively. Experiment A included 4 treated and 4 nontreated calves and experiment B consisted of 5 treated and 5 nontreated calves.

Aggregate removals of Ostertagia spp (4th stage), O ostertagi (adult), Trichostrongylus spp (4th stage), and T axei (adult) were 0%, 54%, 86%, and 95%, respectively, for injectable-treated calves and were 0%, 23%, no data, and 85%, respectively, for bolus-treated calves. Haemonchus spp, present in small numbers, were completely removed from treated calves in experiment A.

Several possible explanations are discussed regarding poor removal activity of levamisole by both formulations against O ostertagi. Removal activity was 95% and 100% against Dictyocaulus viviparus for injectable-treated and bolus-treated calves, respectively.
Radiolabeled Substrate Assay to Measure Inhibition of Growth of Haemophilus somnus by Normal Bovine Serum
Authors: Simonson R. R. , Maheswaran S. K. , Ward G. E.
Published: February 2025

An assay was developed to measure the inhibition of cell division of Haemophilus somnus by normal bovine serum. Dilution plate counts, turbidometric measurements, and release of radiolabeled cell constituents were found to be time-consuming or difficult to perform and reproduce. This assay determined the inhibitory effect of normal serum on population growth, by measuring the relative rate of macromolecular (DNA) synthesis in exponential cultures. This method was simple to perform and gave reliable results in 1 day. When this assay was used, a significant difference (P < 0.025) in serum susceptibility was demonstrated between a H somnus isolate recovered from the trachea of a healthy calf and an isolate recovered at necropsy from a brain lesion of a cow. The implication of this finding, in relation to the pathogenicity of the organism, it briefly discussed.
Detection of Mycoplasma bovis Specific IgG in Bovine Serum by Enzyme-Linked Immunosorbent Assay
Authors: Boothby J. T. , Jasper D. E. , Rollins M. H. , Thomas C. B.
Published: February 2025

The enzyme-linked immunosorbent assay (elisa) was optimized for detection of Mycoplasma bovis-specific IgG in bovine serum. The test is rapid, reproducible, convenient, and sensitive. With this assay, the serum from naturally infected and immunized calves demonstrated the presence of antibodies early in infection and rapid increase in titers during the infection. Cross-reactivity of bovine serum with mycoplasma antigens of bovine, caprine, avian, and environmental sources was tested with this assay system. Cross-reaction was measurable in all instances, with the strongest reaction measured between M bovis and M agalactiae.
Serotypes of Previously Unclassified Isolates of Erysipelothrix rhusiopathiae from Swine in the United States and Puerto Rico
Authors: Wood R. L. , Harrington R. , Haubrich D. R.
Published: February 2025

Serotypes of 46 previously unclassified isolates of Erysipelothrix rhusiopathiae from porcine tissues in the United States and serotypes of 31 isolates of the organism from porcine tissues received from Puerto Rico were determined. The 46 isolates from the United States were classified in serotype 21. Four isolates (from Georgia, Minnesota, Ohio, and Oklahoma) were tested and found to be pathogenic for swine. Serotypes 1 (subtypes 1a and 1b), 2, 5, 6, and 21 were found in porcine tissues from Puerto Rico. The relative frequency of the various serotypes was similar to that previously reported in the United States.
Quantitative Evaluation of Neutrophilic Chemotaxis in Beagles
Authors: Latimer Kenneth S. , Crane L. Stanley , Prasse Keith W.
Published: February 2025

A quantitative evaluation of neutrophilic chemotaxis was performed, using neutrophils from 12 healthy Beagles. Dextran sedimentation, differential centrifugation, and hypotonic lysis allowed separation of a neutrophil-rich cell suspension. Chemotaxis was studied, using blind-well chambers with 3-μm (apd) polycarbonate filters. A frozen (—80 C) bank of pooled normal canine serum was used as the chemotactant, and the chemotactant properties of the serum were destroyed by heat inactivation at 56 C for 30 minutes. Based on membrane and lower blind-well chamber solution neutrophil counts, a method was devised to distinguish between normal neutrophilic chemotaxis, normal neutrophilic chemotaxis with decreased neutrophilic adherence, and defective neutrophilic chemotaxis.
Immunogenic Collagen in Induced Ascitic Fluid: Concurrent Preparation of Anti-Murine Immunoglobulin E
Authors: Gershwin Laurel J. , Osebold John W. , Zee Yuan Chung
Published: February 2025

Antiserum to murine immunoglobulin (Ig) E was produced by inoculation of goats with a pool of partially purified IgE from serum and adjuvant-induced ascitic fluid. Antibodies to collagen were found to be present in the antiserum when the latter was conjugated with fluorescein isothiocyanate and applied to mouse pulmonic tissue. The intense connective tissue fluorescence was eliminated following absorption with mouse collagen. Immunogenic collagen components were presumed to arise in ascitic fluid as a consequence of the adjuvant-induced inflammation. Ascitic fluid is commonly used when large volumes of serum proteins are collected from small mammals. It is suggested that ascitic fluid may not be an ideal antigen source when antiserum is to be used for immunofluorescence studies on tissue.
Inheritance of Cambendazole Resistance in Haemonchus contortus
Authors: Herlich Harry , Rew Robert S. , Colglazier Merle L.
Published: February 2025

Fourth-molt larvae (M4) of cambendazole-resistant (CBZ-R) and cambendazole-susceptible (BPL) strains of Haemonchus contortus were recovered from donor lambs and inoculated orally into source lambs to effect mating in a 2nd lamb. Eggs produced by these parasitic matings were collected, cultured, and inoculated into lambs to compare the anthelmintic activity of cambendazole (cbz), given at a dose rate of 20 mg/kg, against the F1 adults with its activity against the 2 parental strains (CBZ-R and BPL). In 2 replications, cbz was 94% and 99% efficacious against the progeny of the cross matings and 91% and 95% against the BPL strain; cbz was only 39% and 42% efficacious against the CBZ-R strain. In 1 test of F2 progeny of the reciprocal matings, cbz was 81.2% efficacious against the F2 adults, whereas cbz was 97.5% efficacious against the BPL strain and 37% against the CBZ-R strain. The results indicated that heredity of resistance to cbz in H contortus is not sex-linked and is probably a result of a heterozygous recessive allele. The infective larvae of the CBZ-R groups in these 3 trials were from the 20th and 24th passages through lambs without exposure to any anthelmintics, yet the anthelmintic activity of cbz ranged from 37% to 42%, indicating that there had been no reversion to susceptibility.
Total and Differential Somatic Cell Counts in Secretions from Noninfected Bovine Mammary Glands: The Peripartum Period
Authors: McDonald J. S. , Anderson A. J.
Published: February 2025

In 3 cows, mean total somatic cell counts in mammary gland secretions were > 1 × 106/ml from 25 days before parturition until parturition. Cell population decreased rapidly after parturition, and 10 days after parturition, all counts in foremilk were < 1 × 105/ml.

Macrophages and lymphocytes in equal numbers were present in secretions before parturition. Starting approximately 5 days before parturition, lymphocytes decreased so that they were absent at parturition. Nearly all cells in secretions after parturition were macrophages. Polymorphonuclear neutrophils were in low numbers or absent from all secretions.
Interferon, Fluorescent Antibody, and Neutralizing Antibody Responses in Sera of Calves Inoculated with Bovine Respiratory Syncytial Virus
Authors: El Azhary M. A. S. Y. , Silim A. , Roy R. S.
Published: February 2025

Interferon, fluorescent antibody, and neutralizing antibody responses were studied in sera of 9 calves inoculated with bovine respiratory syncytial virus, in relation to viral shedding and clinical signs of disease. The calves (5.5 to 6.5 weeks of age) were assigned to 3 groups. Group I was inoculated once with the virus, and groups II and III were challenge exposed at postinoculation day (pid) 15 or 37. Serum-neutralizing and indirect fluorescent antibody techniques were used to measure antibody responses. The plaque-inhibition technique, using vesicular stomatitis virus, was applied to measure serum interferon titers. The virus was recovered by inoculation of nasal secretions onto cell cultures.

Fluorescent antibody was detected in all calves on pid 3, with maximum titers appearing approximately on pid 10. Low neutralizing antibody was detected in most animals on pid 3, and titers peaked approximately 4.5 weeks after inoculation and then decreased. Interferon titers were high in all calves during the early stage of infection, dropped to undetectable amounts by pid 6, and reappeared in low amounts at least 1 week later. All infected calves manifested clinical signs of disease by pid 4 to 9. Clinical signs of disease were not observed after challenge exposure at pid 15 or 37, and anamnestic responses were not detected. Virus was recovered after challenge exposure at pid 15, but not at pid 37.
Development of a Chemically Altered Pasteurella multocida Vaccinal Strain
Authors: Kucera C. J. , Wong J. C. S. , Eis R. L.
Published: February 2025

The immunogenic properties of a chemically altered strain of Pasteurella multocida were studied. The chemically altered vaccinal strain, 76-63M, afforded calves, swine, and sheep protection against challenge exposure with virulent P multocida organisms.

A high degree of protection was elicited in mice and hamsters vaccinated with the experimental vaccine. The chemically altered strain of P multocida compared favorably with reference bacterin standards in inducing resistance to challenge exposure.
Correlation of Blood Lymphocyte Nuclear Pocket Prevalence with Enzootic Bovine Leukemia p24 Viral Antibody Titers
Authors: Weber A. , Bingham C. , Pomeroy K.
Published: February 2025

The quantitative relationship between radioimmunoassay serotiters to p24 enzootic bovine leukemia viral antigen and the prevalence of lymphocytic nuclear pockets (lnp) was studied in 554 clinically normal dairy cows and bulls.

Of the animals, 69% were seronegative. Of the seronegative animals, 44% had no observed lnp, whereas 93% of the seronegative animals had < 1% lnp. However, 2.3% of the seronegative animals had substantially increased (> 2%) numbers of lnp, and conversely, 24% of the seropositive animals had no observed lnp.

Statistical evaluation of the data, using contingency table and regression methods, provide significant (P < 0.0001) evidence for a positive association between lnp prevalence and p24 bovine leukemia viral serotiters. Although significant, the association was weak, and hence lnp number had little value for predicting serotiter.
Temporary Plasma-Induced Remission of Lymphoblastic Leukemia in a Dog
Authors: MacEwen E. Gregory , Patnaik Amiya K. , Hayes Audrey A. , Wilkins Robert J. , Hardy W.D. , Kassel Robert L. , Old Lloyd J.
Published: February 2025

A mixed-breed dog with lymphoblastic leukemia was treated with infusions of freshly collected heparinized plasma and whole blood over a 42-day period. Remission (absence of clinical or hematologic abnormalities) was achieved, demonstrating that the blood of normal animals contains an anti-leukemia substance. The dog remained in remission without additional treatment for 19 months, at which time recurrence of the leukemia was diagnosed. Attempts to achieve a 2nd remission with similar blood constituents were unsuccessful.
Studies with Equine Infectious Anemia Virus: Transmission Attempts by Mosquitoes and Survival of Virus on Vector Mouthparts and Hypodermic Needles, and in Mosquito Tissue Culture
Authors: Williams D. L. , Issel C. J. , Steelman C. D. , Adams W. V. , Benton C. V.
Published: February 2025

Biological and mechanical transmission trials with Psorophora columbiae (Dyar and Knab) and Aedes sollicitans (Walker) and ponies acutely infected with equine infectious anemia virus (eiav) were negative. The eiav antigen was detected by radioimmunoassay in Ae sollicitans immediately after the mosquitoes had fed on an acutely ill pony, but not 14 days after feeding. Psorophora columbiae mosquitoes had detectable eiav antigen as determined by radioimmunoassay 24 hours after they fed on an acutely ill pony; this antigen was not detected again until 6 days after feeding and was still detected 14 days after feeding.

The eiav was detected on hypodermic needles held at 25 C for 96 hours, but was not detected 120 hours after the needles were dipped in solutions of eiav. The virus was detected on the mouthparts of mosquitoes for 1 hour after they had fed on an eiav-rich medium, but was not detected 4 hours after feeding.

Culex pipiens quinquefasciatus Say ovarian cells maintained the infectivity of eiav for 10 weekly passages, but no evidence for virus multiplication was obtained.
Endotoxin-Induced Hemodynamic Changes in Ponies: Effects of Flunixin Meglumine
Authors: Bottoms Gerald D. , Fessler J. F. , Roesel O. F. , Moore Alfred B. , Frauenfelder Harry C.
Published: February 2025

A study was made of flunixin meglumine, an analgesic agent with antiinflammatory and antiprostaglandin activity, for the management of endotoxin-induced cardiovascular derangements. Three groups of 5 ponies each were used: controls—group 1; given endotoxin but not treated—group 2; and given endotoxin and treated with flunixin meglumine—group 3. Shock was induced in anesthetized ponies with iv injection of Escherichia coli endotoxin. Hemodynamic changes were monitored, and regional blood flow was determined at 4 different times, using microspheres labeled with 1 of 4 nuclides.

There were extensive vasodilation and decreased blood return to the heart of group 2 ponies, as indicated by decreased mean arterial blood pressure and central venous pressure and by increased heart rate and cardiac output. Blood flow, as determined by radioactive microspheres, to gastrointestinal regions, skeletal muscle, and skin was increased and that to the cns was decreased. Treatment with flunixin meglumine (group 3 ponies) exerted selective microvascular actions which helped to reverse endotoxin-induced changes. This included the maintenance of mean arterial blood pressure and the enhanced perfusion of vital organs (eg, brain and heart) by preventing extensive vasodilation in the gastrointestinal tract.
Cortical Cataracts Induced by Hygromycin B in Swine
Authors: Sanford S. E. , Dukes T. W. , Creighton M. O. , Trevithick J. R.
Published: February 2025

Conventionally raised Yorkshire cross-bred pigs which were continuously fed hygromycin B at dose levels of 66 g and 13.2 g/1,000 kg of commercial feed (groups 1 and 2) developed cortical cataracts after 10 and 14.3 months, respectively. Cataracts did not develop during this same period in control pigs (group 4) fed the same commercial diet without added drug (group 4) or in pigs (group 3) fed hygromycin B intermittently (13.2 g/1,000 kg for 8 weeks and then off for 8 weeks).

Sows in private herds in Ontario and Quebec which had been affected have not developed new cataracts in the 2 years since usage of hygromycin B as an anthelmintic was stopped.
Nonuniform Horizontal and Vertical Distributions of Immunoglobulin A Cells in Canine Intestines
Authors: Willard M. D. , Leid R. W.
Published: February 2025

The horizontal and vertical distributions of immunoglobulin (Ig) A cells were determined in canine intestines by immunoperoxidase assay on formalin-fixed, paraffin-embedded tissues. With this technique, excellent preservation of tissue morphology was obtained, and special tissue fixation and handling were not required.

Immunoglobulin A cells were counted in 2 different ways at different magnifications. It was seen that (i) the duodenum usually had the highest cell counts at all levels of the lamina propria, (ii) IgA cells in the zone closest to the intestinal lumen became less numerous caudad from the duodenum to the colon, (iii) the zone closest to the submucosa (zone D) had the fewest IgA cells in the small intestines, and (iv) the IgA cell counts in zone D tended to be lowest in the jejunum and ileum and highest in the duodenum and colon.
Biomechanical Analysis of Forces Acting About the Canine Hip
Authors: Arnoczky Steven P. , Torzilli Peter A.
Published: February 2025

The forces acting about the canine hip were calculated from measurements obtained from a radiograph of the pelvis and femur. It was found that during a 3-legged stance, the single weight-bearing hip was subjected to a force approximately 1.5 times body weight. Increasing the femoral neck angle and/or abducting the hip resulted in an increase in hip and abductor muscle forces, whereas decreasing the femoral neck angle and/or adducting the hip decreased these forces. Subluxation of the femoral head also increased both the abductor muscle force and hip force.
Monosynaptic Reflex (H Wave) in Clinically Normal and Abnormal Dogs
Authors: Knecht Charles D. , Redding Richard W.
Published: February 2025

A monosynaptic reflex (H wave) was recorded in 10 clinically normal dogs and in 5 dogs with paresis and clinical signs of lumbosacral disease. The tibial nerve proximal to the hock was stimulated with an electrical rectangular pulse. Optimal duration of stimulus was 0.1 ms. A submaximal stimulation (30 to 37 V) produced optimal waves with latency rates of 30 to 50 m/s. Testing with the H wave should permit evaluation of the afferent and efferent nerve function and the synapse in the spinal cord.
Freeze-Preserved Baboon Red Blood Cells: Effects of Biochemical Modification and Perfusion in Vitro
Authors: Valeri C. R. , Lindberg J. R. , Contreras T. J. , Lowrie G. B. , Pivacek L. E. , Gray A. , Valeri D. A. , Emerson C. P.
Published: February 2025

Nonrejuvenated and rejuvenated baboon rbc were freeze-preserved with 40% (w/v) glycerol at —80 C. To prepare rejuvenated rbc, a 50-ml solution containing pyruvate, inosine, glucose, phosphate, and adenine was used and rbc were incubated with this solution before glycerolization and freezing. Appropriate steps were taken to minimize osmotic damage to the rbc during glycerolization and deglycerolization. Nonrejuvenated and rejuvenated cryopreserved rbc had freeze-thaw recovery values of 98%, freeze-thaw-wash recovery values of 92%, and 24-hour posttransfusion survival values of 85%.

Some units of cryopreserved rbc were autotransfused after thawing, washing, and storage at 4 C for 24 hours. Other units were perfused in vitro before autotransfusion. After 24 hours of postwash storage, the rbc were concentrated by centrifugation and suspended in a plasma protein fraction and/or an electrolyte solution, and then were exposed to extracorporeal perfusion. Serious adverse effects were not observed on posttransfusion survival, function, or hemolysis in nonrejuvenated or rejuvenated baboon rbc as a result of perfusion in vitro.
Ultrastructure of Haemophilus somnus, Causative Agent of Bovine Infectious Thromboembolic Meningoencephalitis
Authors: Stephens L. R. , Little P. B.
Published: February 2025

Electron microscopic examination of Haemophilus somnus showed it to have a cell envelope typical of gram-negative bacteria. Using negative staining, pili were not seen, and thin sections of ruthenium red-stained bacteria did not reveal a polysaccharide capsule.
Inheritance of Microphthalmia with Coloboma in the Australian Shepherd Dog
Authors: Gelatt Kirk N. , Powell N. Gail , Huston Keith
Published: February 2025

Microphthalmia with coloboma behaves as an incompletely penetrant recessive trait in the merle Australian Shepherd dog. Microphthalmia and related anomalies occurred more often in merle dogs with predominate white than in merles with limited white hair coat. The study did not establish a genetic relationship between the amount of merling and microphthalmia.

The inheritance of merling behaved as a dominant trait, but fewer non-merles occurred than were expected. Variations in white spotting were satisfactorily explained by several hypotheses involving 2 or 3 alleles at the S locus. Each requires some or all homozygous merles to be largely white and 1 or more of the S alleles to exhibit some extent of dominance over other alleles in the series.
Feline Mammary Hypertrophy/Fibroadenoma Complex: Clinical and Hormonal Aspects
Authors: Hayden David W. , Johnston Shirley D. , Kiang David T. , Johnson Kenneth H. , Barnes Donald M.
Published: February 2025

Abnormal mammary enlargement, characterized microscopically by hyperplasia of both epithelial and mesenchymal tissues, was studied in 26 cats which were mostly young, sexually intact females. Clinicopathologic data indicated that mammary hypertrophy was likely progesterone-dependent. Administration of progestins preceded this condition in 5 cats, 4 of which were neutered. Serum progesterone concentrations (6.7 ng/ml) were increased in 1 of the 3 cats tested. Estrogen receptors were not found in the cytosols or nuclei of mammary tissues ih the 2 cats studied. However, there were convincing 4S [3H]progesterone or 5S [3H]R5020 binding peaks which were suppressible by nonlabeled progestins. Progesterone receptors were measured at 14.9 and 8.6 fm/mg of protein, respectively. The apparent influence of progesterone, whether present as exogenous therapy in the male or female or as endogenous steroid of ovarian origin, has thus been demonstrated directly and indirectly in cats with mammary hypertrophy.
Selenium Content and Glutathione Peroxidase Activity in Tissues of Young Cattle Fed Supplemented Whole Milk Diets
Authors: Scholz Richard W. , Todhunter Deborah A. , Cook Lynda S.
Published: February 2025

Three groups of 5 calves each were fed (from birth to 12 weeks of age) 3 vitamin-mineral supplemented whole milk diets differing only in their selenium (Se) content (0.03, 0.23, and 0.53 μg/g of solids). Glutathione peroxidase (gsh-Px) activities and Se concentrations were determined in blood at weekly intervals and in selected tissues after 12 weeks. There were marked differences among the tissues in gsh-Px activity, most notably in the liver, lungs, and adrenal glands, depending on whether H2O2 or cumene hydroperoxide was used to assay the enzyme. Tissues having the highest gsh-Px activity on a weight basis, when assayed with the H2O2 substrate, were erythrocytes and testes. Enzyme activity in thymus, brain, striated muscle, adipose tissue, and blood plasma was lowest among the tissues analyzed. The Se concentration on a fresh tissue-weight basis was highest in kidney cortex, intermediate in kidney medulla, testes, liver, and spleen, and lowest in striated muscle, adipose tissue, and blood plasma. The Se concentration was increased in liver, kidney cortex, spleen, and heart, with increasing increments of dietary Se, whereas differences were not observed in testes and adipose tissue.
Further Studies of Naturally Occurring Latent Bovine Herpesvirus Infection
Authors: Homan E. J. , Easterday B. C.
Published: February 2025

Attempts were made to enhance the isolation rate of latent bovine herpesviruses from trigeminal ganglia by using a fibroblastic fetal bovine kidney cell line, in addition to Madin-Darby bovine kidney cells, and by superinfecting with a temperature-sensitive helper strain of bovine herpesvirus-1 (bhv-1). Four isolates of latent bhv-1 were obtained from 44 pairs of trigeminal ganglia—thus reflecting no increase in isolation rate over that previously observed. Two isolates of a latent bovine herpesvirus indistinguishable from bovine herpesvirus-3 strain DN599 were also obtained.

Analysis of plaque morphology of bhv-1 isolates obtained in this and a previous study indicated that several biologically heterogeneous strains were capable of establishing latent infections.
Use of Enzyme-Linked Immunosorbent Assay for Detecting Mycobacterial Antigens in Tissues of Mycobacterium bovis-Infected Cattle
Authors: Thoen Charles O. , Malstrom Carolyn , Himes Elmer M. , Mills Ken
Published: February 2025

A modified enzyme-linked immunosorbent assay was used for detecting the presence of mycobacterial antigens in the tissues of 20 cattle from which Mycobacterium bovis was isolated. Protein A labeled with horse-radish peroxidase was used as the conjugate in the enzyme-linked immunosorbent assay system.
Proximal Equine Radial and Median Motor Nerve Conduction Velocity
Authors: Henry Robert W. , Diesem C. D.
Published: February 2025

Radial and median motor nerve conduction velocities were determined on 10 clinically healthy 1- to 11-year-old ponies. These velocities were obtained by stimulation at the brachial plexus directly through a surgical incision and later in the ambulatory pony via implanted Formvar-coated wire electrodes. Percutaneous stimulation was used at the cubital region in both anesthetized and ambulatory ponies. The values for radial motor nerve fibers ranged from 96.4 to 100 m/s. These were 15.3% faster than previously reported distal values. Median motor nerve fiber values ranged from 86.8 to 90.2 m/s, which were 14.9% faster than distal velocities. These data showing proximal velocities in the equine to be faster than distal velocities were similar to reported data for persons and dogs.
Egg Transmission of Avian Adenovirus-Associated Virus and CELO Virus During Experimental Infections
Authors: Dawson George J. , Yates V. J. , Chang P. W. , Wattanavijarin W.
Published: February 2025

Hens inoculated with a mixture of avian adenovirus-associated virus (a-av) and CELO virus transmitted these viruses to eggs for 1 week after inoculation. In trial 1, a-av and CELO virus were isolated from fertile eggs of 9 black sex-linked hens (24 to 26 weeks old) housed together. During the period before inoculation, a-av was isolated from 4 of 53 fertile eggs from these hens; serologic data indicated that 4 hens were undergoing a natural infection with a-av and CELO virus. From postinoculation day (pid) 1 through 8, a-av was isolated from 13 of 62 (20.9%) and CELO virus was isolated from 18 of 62 (29.0%) eggs tested. Viruses were not isolated from pid 9 through 16. Neither virus was isolated from eggs after reinoculation of the hens 3 months later. In trial 2, a-av and CELO virus were isolated from nonfertile eggs of 4 White Leghorn hens inoculated with a mixture of these viruses. From pid 1 through 8, a-av was isolated from 7 of 14 (50%) and CELO virus was isolated from 3 of 14 (21.4%) nonfertile eggs. Viruses were not isolated from eggs from pid 9 through 20. After reinoculation at pid 25, neither virus was isolated from eggs. Viral isolations were not made from 4 noninoculated hens.

All hens that transmitted a-av and/or CELO virus to eggs also showed 4-fold increases in antibody concentrations.

The a-av was isolated from fecal material from inoculated hens in trial 2 as late as pid 10, and CELO virus was isolated as late as pid 15.

Viral isolation attempts from seminal samples taken from a rooster inoculated with a-av and CELO virus were negative for both viruses before and after inoculation.

There was no histologic evidence that a-av or CELO virus were replicating in the oviduct or uterus of infected hens examined at pid 3 and 4.
Early, Asymptomatic Stage of Degenerative Joint Disease in Canine Hip Joints
Authors: Lust George , Summers Brian A.
Published: February 2025

The early stages of degenerative joint disease were investigated in coxofemoral joints from dogs with a hereditary predisposition to hip dysplasia. Alterations observed included mild nonsuppurative synovitis, increased volume of both synovial fluid and the ligamentum teres, and focal degenerative articular cartilage lesions. On radiologic examination, subluxation of the femoral head was seen, but only in the most severely affected joints. Synovial inflammation with increased synovial fluid and ligament volumes were indicators of early degenerative joint disease in dogs. These changes seemed to coincide with, or perhaps to precede, microscopic evidence for articular cartilage degeneration and occurred before radiologic abnormalities were detected.
Kinetics of Gentamicin After Intravenous, Intramuscular, and Intratracheal Administration in Sheep
Authors: Wilson R. C. , Whelan S. C. , Coulter D. B. , Mahaffey E. A. , Mahaffey M. B. , Huber T. L.
Published: February 2025

Kinetics of gentamicin (2.2 mg/kg of body weight) were investigated in 7 sheep after iv bolus administration. The mean serum concentration profile could be described by a 2-compartment open model with a distribution rate constant (α) of 3.112 ± 1.681 hour−1 [half-life, t1/2(α) = 17.22 ± 8.63 minutes] and an overall elimination rate constant (β) of 0.485 ± 0.028 hour−1 [t1/2(β) ± 85.87 ± 5.03 minutes]. The apparent volume of distribution was somewhat restricted [Vd(area) = 0.194 ± 0.059 L/kg], and the total body clearance was 1.559 ± 0.400 ml/kg/min.

Equal dosages of gentamicin (2.2 mg/kg) were also given im and intratracheally (it). After im injection, gentamicin reached peak serum concentration at postinjection minutes (pim) 45, surpassing concentrations after the iv injection for the remainder of the experiment. The it injection produced detectable serum concentrations at pim 5, with a peak concentration at pim 60. The serum drug concentrations after it injections remained well below concentrations after iv and im injections.

Radiographic analysis of an it injection of a gentamicintantalum suspension revealed good distribution throughout the trachea and proximal bronchi, with physical clearance of the tantalum occurring after ≥ 10 minutes. Aspiration biopsy of a tracheal wash 6 hours after it gentamicin injection revealed no cytologic response to gentamicin in 6 of 7 sheep, with the single response that of a purulent exudate.
Induction of Protective Immunity to Strongyloides ransomi in Pigs
Authors: Murrell K. D.
Published: February 2025

Pigs inoculated once or twice with infective Strongyloides ransomi larvae (L3) developed a strong protective immunity to challenge exposure. Intestinal expulsion of adult worms resulting from initial infection occurred 3 to 4 weeks after inoculation; worm loss reached 68% by 52 days after inoculation. Necropsy of pigs at various times after challenge exposure with infective L3 revealed that the majority of migrating L3 were eliminated before reaching the intestine; based on parasitic recoveries from the lung, the reduction was manifested as early as 48 hours after challenge exposure. Evidence for enhanced migration of L3 to the fat tissue in immune pigs could not be detected. Data indicate that infective L3 possess functional antigens capable of inducing protective immunity. Treatment of infected pigs with ivermectin was effective in removing arrested L3 in the subventral fat; 85% of these larvae were eliminated in 3 weeks. The role of milk-transmitted arrested L3 in the immunology of porcine strongyloidiasis is discussed.
Somatic and Capsular Factors of Coliforms Which Affect Resistance to Bovine Serum Bactericidal Activity
Authors: Ward G. E. , Sebunya T. K.
Published: February 2025

Killing of bacteria which cause acute coliform mastitis was studied in vitro, using serum without exogenous complement. Using 10% freshly collected whole serum, it was found that some strains were killed rapidly and could be classified as serum sensitive and others were killed less rapidly and could be classified as intermediate serum sensitive. With other strains, fewer were killed, and then the survivors multiplied; these could be classified as serum resistant. A 50-percentage kill of serum-resistant strains could not be achieved with serum (even in concentrations of > 90% serum), whereas 15 strains showed 50-percentage kill at appropriate serum concentrations.

Resistance of Escherichia coli to serum bactericidal activity was greatest in strains with large amounts of heat-labile capsule present. The capsule could be demonstrated, using a test for somatic inagglutinability and a hemagglutination-inhibition test.

Resistance of Klebsiella pneumoniae to serum bactericidal activity was not related to somatic inagglutinability. In K pneumoniae, resistance to serum bactericidal activity was related to presence of somatic antigens on the resistant strain.
Clinicopathologic Evaluation of N-Acetylcysteine Therapy in Acetaminophen Toxicosis in the Cat
Authors: Gaunt Stephen D. , Baker Dale C. , Green Robert A.
Published: February 2025

Acute acetaminophen (acm) toxicosis was induced in cats and the therapeutic benefit of N-acetylcysteine (nac) was demonstrated. Groups of 4 adult cats were treated as follows: group A—given acm only; group B—given acm and then treated with nac, starting at 0 hour; group C—given acm and then treated with nac, starting at 4 hours; and group D—treated with nac only. Acetaminophen was given as a single oral dose of 143 mg/kg, and the nac regimen consisted of 4 oral doses (200 mg/kg, given 3 times, and 100 mg/kg, given once) with 2 horn's between doses. Group A cats developed increased methemoglobin concentration, depletion of erythrocyte reduced glutathione, and increased Heinz body formation. Group B cats also developed methemoglobinemia, depletion of glutathione, and increased Heinz body formation, but the magnitude of these changes was significantly less (P < 0.05) than in group A. In group C, the findings were similar to group A through 4 hours, but thereafter, significant hematologic improvement was noted. The level of Heinz bodies in group C was intermediate between the values for groups A and B. In group D cats, no significant changes from base line were noted. Evidence of hepatotoxicity was not seen in any group as based on daily determinations of plasma alanine aminotransferase and sorbitol dehydrogenase activities.
Assay of Penetrability of Bovine Papillary Duct Implanted with Escherichia coli Endotoxin
Authors: Schultze W.D.
Published: February 2025

A method has been developed to assay the relative penetrability to a solute of the papillary duct (streak canal) of the bovine teat. Escherichia coli lipopolysaccharide endotoxin (1.0 μg in 2.5 μl of sterile distilled water) was implanted at a depth of 3 mm from the distal end (papillary orifice) of the papillary duct. If penetration by the irritant occurred after any one of 5 successive daily implantations, the inflammatory response of the mammary gland was detected by a precipitous increase (by at least 15 mm) in the Wisconsin mastitis test score of quarter foremilk samples, and the test was scored as positive.

Results of the penetrability assay were highly repeatable among quarters of certain cows. Cows differed as to the pattern of penetrability of their papillary ducts, with about half of 70 tested cows scoring 4 positive or 4 negative.
Decreased Motility of Bull Spermatozoa Caused by Mycoplasma bovigenitalium
Authors: Panangala V. S. , Winter A. J. , Wijesinha A. , Foote R. H.
Published: February 2025

Mycoplasma bovigenitalium mixed with bull semen in egg yolk-citrate buffer and held at 5C caused a highly significant time- and dose-dependent depression in sperm motility. Mycoplasma adhered to a majority of spermatozoa, principally to the acrosome, but also to the midpiece and tail. This may reflect the basis for a naturally observed condition in young bulls in which genital mycoplasmosis is associated with low sperm motility.
Anthelmintic Efficacy of Ivermectin Against Immature Gastrointestinal Pulmonary Nematodes of Calves
Authors: Benz G. W. , Ernst J. V.
Published: February 2025

Anthelmintic efficacy of ivermectin (≥ 80% 22,23-dihydroavermectin B1a and ≤ 20% 22,23-dihydroavennectin B2b) was evaluated in a controlled experiment against immature nematodes. Twenty calves raised to about 8 weeks of age under nematode-free conditions were allocated into 4 groups. Infective larvae of Haemonchus contortus, Ostertagia ostertagi, Trichostrongylus axei, T colubriformis, Cooperia oncophora, C punctata, Oesophagostomum radiation, and Dictyocaulus viviparus were given orally to each calf on a staggered schedule 6 to 14 days before treatments. The drug was given subcutaneously when the nematodes were in the early 4th stage of development, and the calves were killed 23 or 24 days later. Group 1 nonmedicated control calves had a geometric mean of 25,102 nematodes; groups 2, 3, and 4 calves given ivermectin at dose rates of 50,100, or 200 μg/kg had reductions of 88.2%, 98.0%, and 99.8%, respectively.
Purification and Biological Characterization of Endotoxin Fractions from Pasteurella haemolytica
Authors: Rimsay R. L. , Coyle-Dennis J. E. , Lauerman L. H. , Squire P. G.
Published: February 2025

A sequential extraction procedure was used to provide 3 endotoxin fractions from Pasteurella haemolytica with distinct biological and solubility properties. After acetone dessication, extraction with phenol, chloroform, and petroleum ether (2:5:8) provided a fraction designated rough lipopolysaccharide (lps). Subsequent extraction of the cells with 45% phenol at 68 C yielded a fraction designated smooth lps, which was further divided into smooth precipitate and smooth supernatant, based on sedimentation at 105,000 × g for 4 hours. Yields of the 3 fractions were 1.5%, 3%, and 5.5% of the dry weight of the cells. The polysaccharide moieties of the rough lps and smooth precipitate fractions were obtained by partial acid hydrolysis followed by chloroform extraction.

Biological activities of all 5 fractions were compared with activities of standard lps fractions from Serratia marcescens and Salmonella typhimurium. Results of chicken embryo lethality, the local Shwartzman's phenomenon, nonspecific resistance enhancement to challenge exposure by S typhimurium pyrogenicity, and the Limulus amebocyte lysate assay were reported.