bluuebunny/crossref_metadata_2025 huggingface dataset:
Antibody response to genus- and serovar-specific leptospiral antigens in Leptospira-infected cows
Authors: Fairbrother John M.
Published: February 2025

In cows inoculated with Leptospira interrogans serovar pomona or hardjo, the 2-mercaptoethanol-sensitive microscopic agglutination test (mat) antibody to the serovar appeared 3 to 8 days after inoculation and peaked at 10 to 20 days, whereas the 2-mercaptoethanol-resistant mat antibody was predominant at 35 to 80 days. A persistent antibody response, probably associated with serovar-specific leptospiral antigens, was detected in the cows inoculated with serovar pomona, using a sonicated or an alkaline-extracted antigen derived from serovar pomona in the enzyme-linked immunosorbent assay (elisa). In contrast, a short-lived antibody response to the same antigens was demonstrated in cows inoculated with serovar hardjo, probably more typical of the response to genus-specific leptospiral antigens. Antigens derived from L bi-flexa serovar patoc only detected the latter type of antibody response in cows inoculated with serovar pomona or hardjo. Correlative studies revealed that the antigens derived from serovar patoc seem to be genus specific and serologically closely related, but not identical. The antigens derived from serovar pomona were genus specific on the basis of the early antibody response to leptospiral inoculation in the cows, but serovar specific based on the subsequent more persistent response to leptospiral inoculation. These antigens were also serologically closely related, but not identical. Examination of sera from cows that aborted and were mat-positive for serovar pomona or hardjo revealed a more serovar-specific antibody response, indicating that there may have been a less recent leptospiral antigenic stimulus, thus emphasizing the caution with which results of the elisa and other serologic assays for the detection of bovine leptospirosis must be interpreted.
Diagnosis of ovine fascioliasis by a dot enzyme-linked immunosorbent assay: A rapid microdiagnostic technique
Authors: Zimmerman G. L. , Nelson M. J. , Clark C. R. B.
Published: February 2025

A microenzyme-linked immunosorbent assay (dot-elisa) was modified for making an immunodiagnosis of Fasciola hepatica infections in sheep. Sheep were alloted as follows: group I—3 controls and 4 principals, each inoculated with 500 metacercariae; group II—3 controls and 7 principals, each inoculated with 250 metacercariae; and group III—3 controls and 7 principals, each inoculated with 500 metacercariae. Blood and fecal samples were collected from each animal every 2 weeks for 16 weeks. Presence (or absence) of flukes was confirmed by fecal examinations and examination of dissected livers at necropsy of the sheep.

The dot-elisa incubations were done at ambient room temperature. Nitrocellulose disks dotted with 1 μl (50 ng of protein) of F hepatica excretory/secretory products were placed in 96-well tissue culture plates. After nonspecific binding sites on the disks were bound with bovine serum albumin-triethanolamine-buffered saline solution, dilutions (1:2) of positive- and negative-control serum samples or experimental serum samples were placed in appropriate wells for a 30-minute incubation. Wells were washed (3 times), and 50 μl of horseradish peroxidase conjugated rabbit anti-sheep immunoglobulin G was added to each well for a 30-minute incubation and then aspirated. Substrate solution (4-chloro-l-naphthol, methanol, trieth-anolamine-buffered saline solution, and H2O2; 50 μl) was added for a 30-minute incubation and then aspirated. Disks were air dried for visualization: solid purple dot = positive sample, or no dot = negative sample. According to the dot-elisa, antibodies against F hepatica excretory/ secretory products were consistently detected by 4 weeks after principal sheep were inoculated; no such antibodies were detected in control sheep. At necropsy flukes were found only in inoculated sheep.
Effect of o,p′DDD therapy on endogenous ACTH concentrations in dogs with hypophysis-dependent hyperadrenocorticism
Authors: Nelson R. W. , Feldman E. C. , Shinsako J.
Published: February 2025

The effect of o,p′DDD therapy on the endogenous plasma ACTH concentration was evaluated in 15 dogs with hypophysis-dependent hyperadrenocorticism. Adequate control of hyperadrenocorticism with o,p′DDD was based on the reduction of water consumption to within the normal range, disappearance of clinical signs of lethargy, weakness, alopecia, thin skin, or pendulous abdomen, and an increase in blood cortisol below the normal range after exogenous ACTH administration. Endogenous ACTH concentrations were determined for each dog after the disease was controlled and while they were given o,p′DDD on a maintenance schedule. Endogenous ACTH concentrations increased in 14 of 15 dogs after o,p′DDD therapy, indicating a lack of suppressive effects of o,p′DDD on hypophysis ACTH secreting cells.
Antibodies in bovine serum and lacteal secretions to capsular antigens of Staphylococcus aureus
Authors: Opdebeeck J. P. , Norcross N. L.
Published: February 2025

Pregnant cows were immunized systemically with an encapsulated strain of Staphylococcus aureus (Smith diffuse strain). Antibodies in serum and colostrum were detectable by enzyme-linked immunosorbent assay and prevented capsule production by the Smith diffuse strain in a soft agar medium. Antibody in milk, although detectable by enzyme-linked immunosorbent assay, did not affect the production of capsule in vitro. Antibodies were absorbed from milk and serum, using staphylococcal surface antigen.

In a 2nd experiment, lactating cows were immunized, using Smith diffuse strain antigens in the form of a bacterin or as a surface extract; the bacterin or extract was emulsified in Freund's incomplete adjuvant. Antibody titers in the milk of cows given bacterin were significantly (P < 0.001) greater than titers in the milk of animals immunized with surface extract. The soft agar technique was insufficiently sensitive to detect antibody in the milk of any of the cattle.
Effect of exogenous ACTH on serum corticosterone and cortisol concentrations in the Moluccan cockatoo (Cacatua moluccensis)
Authors: Walsh M. T. , Beldegreen R. A. , Clubb S. L. , Chen C. L.
Published: February 2025

The effects of exogenous adrenocorticortrophic hormone (acth) on the serum corticosterone and cortisol concentrations were determined in 28 mature Moluccan cockatoos (Cacatua moluccensis), a representative of the psittacine species. Birds were randomly assigned to 4 groups (2 acth-treated groups and 2 saline-treated controls). Group I (10 cockatoos [5 males and 5 females]) was given 15IU of acth after blood samples (base line) were taken at 10:00 am. Blood samples were taken again at 30 minutes and 2.5 hours after acth administration. Group II (10 cockatoos) was given similar treatment, but blood samples were taken at 1 and 4 hours after acth was administered. Groups III and IV (each of 4 birds) were given saline solution injections as controls. Blood samples were taken at 30 minutes and 2.5 hours after injection (group III) and at 1 and 4 hours after injection (group IV). All serum samples were analyzed for cortisol and corticosterone.

Serum corticosterone concentration increased significantly (P < 0.01) from base-line levels (26 ng/ml) to 108 ng/ml within 30 minutes after acth was administered. The high values were maintained for 3 hours and then decreased to 40 ng/ml at the end of 4 hours. Male birds seemed to respond to the acth treatment quickly and maintained increased concentration for a shorter period when compared with the responses seen in female birds. Serum cortisol values remained low throughout the experimental period. These results indicate that serum corticosterone was responsive to acth administration, but cortisol was not. In addition, there may be a difference in the responses between male and female members of the species.
A double-protease-resistant variant of transmissible gastroenteritis virus and its ability to induce lactogenic immunity
Authors: Chen Ker-Sang , Kahn Donald E.
Published: February 2025

A virus resistant to 2 major intestinal proteases (trypsin and α-chymotrypsin) was derived from the attenuated Purdue strain of transmissible gastroenteritis virus. Its enzymatic stability was confirmed, in vitro, by exposure to proteolytic enzymes and to porcine intestinal fluids.

Vaccination of 5 seronegative pregnant sows with the variant virus by a series of 2 oral and 1 im inoculations resulted in high titers of neutralizing antibody in serum and colostrum. The mean antibody titer in milk whey decreased 44-fold within 1 week after parturition. At 3 days of age, the 40 pigs delivered by these sows were challenge exposed orally with virulent transmissible gastroenteritis virus. Pigs nursing the 5 vaccinated sows underwent a relatively mild clinical course of illness. The average mortality of these 40 pigs was 33%. Thirty-six pigs which had been raised by 4 nonvaccinated sows had a more severe illness, greater daily weight loss, and higher mortality (92%).
Pathophysiologic effects of experimentally induced Fascioloides magna infection in sheep
Authors: Stromberg B. E. , Conboy G. A. , Hayden D. W. , Schlotthauer J. C.
Published: February 2025

The pathophysiologic responses of 13 sheep inoculated orally with 100 metacercariae of Fascioloides magna were monitored for 4 months after inoculation. There were no differences in weight gains between these and a number of noninoculated control sheep throughout the experiment. Complete blood cell counts showed an increase only in the absolute number of eosinophils. Serum preparations (2 times a week) from 7 inoculated and 7 noninoculated sheep did not identify any significant changes in alkaline phosphatase, aspartate aminotransferase, alanine aminotransferase, and γ-glutamyl transferase activities. There were no changes in total bilirubin, BUN, creatinine, inorganic phosphorus, calcium, albumin, chloride, potassium, and sodium values. Four months after they were inoculated, all sheep were necropsied, and flukes were recovered. Gross lesions attributed to fluke migration were found in the liver and portal lymph nodes, diaphragm, lungs, kidneys, and spleen. Microscopically, liver lesions in inoculated sheep occurred in the portal areas, veins, and Glisson's capsule and were characterized by both active and chronic forms of inflammation. Abundant infiltrates of eosinophils and plasma cells often marked the portal areas. Endophlebitis, with or without thrombosis, was the predominate vascular lesion. The flukes recovered varied greatly in size (6.5 to 48.0-mm long) and demonstrated some sexual development, but none was sexually mature.
Plasma-glucose concentrations in dogs and cats before and after surgery: Comparison of healthy animals and animals with sepsis
Authors: Hardie Elizabeth M. , Rawlings Clarence A. , George Jeanne W.
Published: February 2025

Various surgical procedures were performed in healthy dogs and cats and in dogs and cats with sepsis. Plasma-glucose concentrations after surgery were usually increased over presurgical values. After surgery, cats had significantly higher plasma-glucose concentrations (P < 0.05) than did dogs. Postsurgical concentrations for healthy dogs were between 100 to 200 mg/dl, whereas the concentrations for dogs with sepsis ranged from 66 to 356 mg/dl. Of 8 dogs with sepsis that developed postsurgical plasma-glucose concentrations of > 150 mg/dl, 4 (50%) died, whereas of 7 dogs with sepsis that developed postsurgical concentrations of < 150 mg/dl, only 1 (14%) died; however, the difference between these 2 mortality percentages was not significant (P = 0.08).
Mechanical properties of three orthopedic wire configurations
Authors: Bloss Charles E. , Caldarise Salvatore G. , Torzilli Peter A. , Arnoczky Steven P.
Published: February 2025

An 18-gauge stainless steel wire was applied to a transverse fracture model to determine the antirotational effectivenesses of cruciate, horizontal mattress, and simple interrupted interfragmentary wire configurations. The number of twists used to tighten the configuration and the distance from the fracture were compared in the cruciate and horizontal mattress patterns. In a 2nd experiment, the compressive forces generated at the fracture by cruciate and horizontal mattress configurations tightened with 1 and 2 twists were determined.

The cruciate configuration was better than the horizontal mattress and simple interrupted configurations in preventing rotation (P < 0.001). Increasing the distance from the fracture line to the wire holes decreased antirotational effectiveness. Tightening the cruciate and horizontal mattress configurations with 2 twists produced significantly greater compressions across the fracture line than did tightening with 1 twist (P < 0.0001).
Persistence of encysted Toxoplasma gondii in tissues of equids fed oocysts
Authors: Dubey J. P.
Published: February 2025

Thirteen 6-month- to 13-year-old equids were each inoculated orally with 10,000 infective Toxoplasma gondii oocysts. The equids remained clinically normal. Equids were euthanatized on postinoculation days 33, 45, 90, 104, 120, 140, 162, 183, 197, 204, 211, 294, and 476. Their tissues were bioassayed for viable oocysts by feeding muscles to Toxoplasma-free cats and by inoculation of pepsin digests of 13 organs into mice. Using mouse inoculation, T gondii was recovered from tissues of the 9 equids euthanatized on each of postinoculation days 33, 45, 120, 140, 183, 197, 211, 294, and 476. Toxoplasma gondii was isolated from the tongue and intestines of 4 equids, from the heart of 3 equids, from thigh muscles, brain, and heart of 2 equids, and from the eye, lungs, and spinal cord of 1 equid. Muscles from 9 of 13 equids were infectious to cats, as evidenced by feline shedding of oocysts. Results indicate that T gondii can persist in edible tissues of living equids up to 476 days and that non-cooked horsemeat should not be fed to cats or eaten by human beings.
Distribution of staphylococcal species on clinically healthy cats
Authors: Cox Hollis Utah , Hoskins Johnny D. , Newman Susan S. , Turnwald Grant H. , Foil Carol S. , Roy Alma F. , Kearney Michael T.
Published: February 2025

Among 827 isolates derived from 113 clinically healthy cats, 12 species of staphylococci were identified. Staphylococci were isolated from each cat and from 54.9% of the anatomic sites evaluated. A mode of 6 (range = 2 to 11) of the 11 anatomic sites evaluated per cat yielded staphylococci. A mode of 8 (range = 2 to 12) isolates were found per cat. Staphylococcus simulans was the most isolated (43.9% of total) coagulase-negative species. Moreover, S simulans was the most isolated species from each of the 11 sites evaluated and, except for the mouth and haircoat, comprised > 50% of the isolates from each site. Staphylococcus intermedius was the most isolated (13.5% of the total) coagulase-positive species. Three other species (S epidermidis, S xylosus, and S aureus) comprised 32.2% of the isolates, and 7 species (S haemolyticus, S hominis, S hyicus, S capitis, S warneri, and S saprophyticus) comprised 10.4% of the isolates.

Six species (S intermedius [96 of 112 isolates], S haemolyticus [20 of 22], S sciuri [17 of 18], S warneri [10 of 13], S hyicus [10 of 10], and S capitis [7 of 8] were isolated primarily from household cats. Only 1 species, S xylosus (75 of 87), was isolated primarily from cattery cats. Haircoat specimens (n = 452) yielded 508 isolates (61.4% of the total) distributed among all 12 staphylococcal species and included > 50% of the isolates of all species other than S simulans and S sciuri.

A more heterogenous population of staphylococci was isolated from household cats than was isolated from cattery cats.
Gastric emptying of liquids in the dog: Serial test meal and modified emptying-time techniques
Authors: Leib Michael S. , Wingfield Wayne E. , Twedt David C. , Williams Anne R.
Published: February 2025

A serial test meal technique was used in the dog to evaluate the gastric emptying of a liquid test meal. On separate days, a phenol red test meal was placed in the stomach and completely aspirated at different times. A composite representation of the gastric emptying pattern was obtained for each dog, and a set of normative data was generated. Three emptying determinants (emptying time, half-life, and starting index) were calculated. The basic pattern of canine gastric emptying was linear and declined exponentially or as a function of the square root of the gastric volume.

A modified emptying-time technique (mett) correlated well with the serial test meal and a set of normative values was determined. The mett was performed by aspirating test meal from the stomach 30 minutes after instillation. The mett was a simple and inexpensive technique that could be performed in 1 short testing period. With the mett, the half-life of gastric emptying was calculated, using the log of the percentage of retention of test meal; gastric emptying time was calculated, using the square root of the percentage of retention of test meal. Acetylpromazine was shown not to alter gastric emptying of a liquid test meal.
Antileukotoxin antibody produced in the bovine lung after aerosol exposure to viable Pasteurella haemolytica
Authors: Moore R. N. , Walker R. D. , Shaw G. A. , Hopkins F. M. , Shull B. P.
Published: February 2025

Experiments were performed to determine the in vivo immunogenicity of Pasteurella haemolytica leukotoxin. Calves were exposed twice to aerosol mists of viable P haemolytica, using a treatment regimen previously shown to induce a resistant state. Pulmonary lavage fluids and serum samples from these calves were assayed for leukotoxin-neutralizing antibodies. Before aerosol exposure, neutralizing antibody titers were routinely found in serum samples, but were not detectable in pulmonary lavage concentrates before exposure. After aerosol exposure, titers of toxin-neutralizing immunoglobulin (Ig)A and IgG antibodies were found in pulmonary lavage concentrates and were accompanied by increased serum toxin neutralization titers.
Association of blood cholesterol with occurrence of fat necrosis in cows and tall fescue summer toxicosis in steers
Authors: Stuedemann J. A. , Rumsey T. S. , Bond J. , Wilkinson S. R. , Bush L. P. , Williams D. J. , Caudle A. B.
Published: February 2025

Factors associated with fat necrosis in cows and tall-fescue summer toxicosis in steers were studied. In the cow study, fescue pastures were fertilized, using 3 rates of N: high N (703 to 483 kg and 0 kg of N/ha/year from broiler litter in 1972 to 1974 and 1975, respectively), moderate N, and low N (224 and 74 kg of N/ha/yr from NH4NO3, 1972 to 1975, respectively). Bermuda grass pastures were fertilized at 2 rates of N: moderate N and low N (280 and 20 kg of N/ha/year from NH4NO3, 1972 to 1975, respectively). Fat necrosis developed only in cows grazing tall fescue, with an occurrence of 60%, 8%, and 3% for high-N, moderate-N, and low-N pastures, respectively. Cows grazing the high-N fescue, and to some extent those grazing the moderate-N fescue, had clinical signs of summer fescue toxicosis. Plasma cholesterol concentrations were lowest in cattle grazing the high-N fescue, averaging 114 mg/dl, followed by 134 and 127 mg/dl in cattle grazing the moderate-N and low-N fescue, respectively.
Effects of Escherichia coli heat-stable enterotoxin, atropine, clonidine, and morphine on chloride efflux from isolated enterocytes
Authors: Ahrens Franklin A. , Panichkriangkrai Warn
Published: February 2025

The effects of Escherichia coli heat-stable enterotoxin (st) on chloride efflux rate were investigated in 3 fractions of enterocytes isolated in a villus-to-crypt gradient from porcine jejunum. There was no difference in chloride efflux rates between mature and immature cells from controls. Heat-stable enterotoxin significantly increased chloride efflux in all fractions. Morphine inhibited st-augmented secretion in mature enterocytes. Atropine or Clonidine had no effect. Calcium efflux rates and glucose or glutamic acid metabolism were not altered by st. The results indicate that st may stimulate chloride secretion in both villus and crypt cells and that opiates inhibit intestinal secretion by a direct action on villus epithelial cells.
Effect of pretreatment with selenium-vitamin E on monensin toxicosis in cattle
Authors: Van Vleet John F. , Amstutz Harold E. , Rebar Alan H.
Published: February 2025

Ten female beef calves weighing approximately 180 kg each were allotted to 2 groups of 5 each before they were given (orally) monensin (50 mg/kg of body weight). In group A, the calves were given (im) a commercial selenium-vitamin E (Se-E) preparation (0.25 mg of Se and 17 IU of α-tocopherol/kg of body weight) at 72 and 24 hours before monensin was given. The calves in group B were injected at the 2 times with isotonic saline solution. Clinical signs of monensin toxicosis, including lethargy and recumbency, appeared on day 2 in the calves given the Se-E pretreatment, compared with the onset on day 1 in the saline solution-pretreated calves. All calves in the 2 groups died, but mean survival time was longer in group A (4.4 vs 2.2 days). Lesions of monensin toxicosis were myocardial necrosis, skeletal myonecrosis, pulmonary congestion, and rumenitis. The frequency and severity of the lesions were similar for both groups of calves. The results of the present study indicate that Se-E pretreatment modifies the development of monensin toxicosis in cattle.
In vitro and in vivo evaluation of lysozyme extracts of virulent Mycobacterium bovis in guinea pigs and calves
Authors: Hall Michael R. , Thoen Charles O.
Published: February 2025

Extracts of Mycobacterium bovis ATCC 19210 were prepared from cells following treatment with acetone 3 times, ethyl alcohol-ether 3 times (1:1, v/v), and chloroform 3 times. Cells were dried and suspended in 0.05M Tris-HCl (pH 7.5) containing lysozyme (1 mg/50 mg of dried cells). One aliquot of the lysozyme extract was filter-sterilized and 1 aliquot of the lysozyme extract was autoclaved. Delayed-type hypersensitivity responses elicited in sensitized guinea pigs, using the filter-sterilized lysozyme extract, were significantly greater than responses elicited using the autoclaved lysozyme extract (P < 0.01). The filter-sterilized lysozyme extract and a purified protein derivative (ppd) of M bovis, at equal protein concentrations, elicited comparable delayed-type hypersensitivity responses in sensitized guinea pigs.

Significant differences were not detected between the mean enzyme-linked immunosorbent assay (elisa) values on sera collected from calves before exposure to M bovis, using each of the lysozyme extracts or the M bovis ppd (P > 0.05). Significant differences were detected when elisa values obtained using each of the antigens on postexposure serum were compared with elisa values on serum collected from calves before exposure to M bovis (P < 0.01). Differences were not detected in mean elisa values on sera from cattle collected 12 months after exposure to M bovis, using each of the lysozyme extracts or M bovis ppd (P > 0.05); howeve\r, 8 of 8 calves were identified as positive on elisa, using the filter-sterilized lysozyme extract, 7 of 8 calves were positive, using M bovis ppd, and 7 of 8 calves were positive, using the autoclaved lysozyme extract.
Urinary γ-glutamyl transpeptidase activity in dogs with gentamicin-induced nephrotoxicity
Authors: Greco Deborah S. , Turnwald Grant H. , Adams Ragan , Gossett Kent A. , Kearney Michael , Casey Harold
Published: February 2025

Serum creatinine concentrations, 24-hour endogenous creatinine clearance, and 24-hour urinary γ-glutamyl transpeptidase (uggt) activity were measured daily in 6 dogs given nephrotoxic dosages of gentamicin (10 mg/kg of body weight) every 8 hours for 10 days. Mean uggt activity was significantly increased by day 5 (P < 0.05) and preceded significant increases in serum creatinine values (> 2.0 mg/dl) observed on day 9. Endogenous creatinine clearance remained within normal limits (2.98 ± 0.96 ml/min/kg) until day 8. Urinalyses performed 8 days after initiation of gentamicin treatment indicated renal tubular damage (granular casts) in 1 of the 6 dogs, and glucosuria in 3 of the 6 dogs. Measurement of uggt activity was a more sensitive and reliable method of assessing acute renal tubular damage induced by gentamicin than were serum creatinine concentrations or 24-hour endogenous creatinine clearance.
Passive protection of segmented swine colonic loops against swine dysentery
Authors: Joens L. A. , DeYoung D. W. , Glock R. D. , Mapother M. E. , Cramer J. D. , Wilcox H. E.
Published: February 2025

Swine-ligated loops were used to demonstrate passive protection against swine dysentery. Loops inoculated with immune sera containing complement and with homologous Treponema hyodysenteriae were normal at necropsy. Loops inoculated with heat-inactivated immune sera and heterologous T hyodysenteriae were not protected. Loops inoculated with heat-inactivated immune sera and homologous T hyodysenteriae were partially protected. Positive control loops inoculated with isolate B204 (88%) or B234 (44%) T hyodysenteriae and normal sera developed lesions typical of swine dysentery, whereas negative control loops inoculated with nonexposed sera only were normal.
Modified indirect fluorescent antibody test for the serodiagnosis of Anaplasma marginale infections in cattle
Authors: Montenegro-James Sonia , James Mark A. , Ristic Miodrag
Published: February 2025

A modified indirect fluorescence antibody technique was used for the serodiagnosis of Anaplasma marginale infections in cattle. Nonspecific antibodies adherent to infected erythrocytes were removed, using acidic glycine buffer. Evans blue was used as a counterstain.
Microangiography and correlated histology: A research technique for examining renal microcirculation
Authors: Ludders J. W. , Wilson J. W. , Ribble G. A.
Published: February 2025

A technique for radiographic delineation of the micro-vasculature of the canine kidney is described.

The renal vasculature was perfused (at a physiologic pressure) with a finely divided barium sulfate. Microangiograms of sagittal renal slices were produced, using a special radiography machine that allows low kilovolt peak, low milliamperage, and exposure times up to 5 minutes. A special high resolution film (800 lines/mm) was used. With this technique, it was possible to delineate interlobar, arcuate, and interlobular arteries, afferent arterioles, glomerular capillaries, and peritubular vessels. The kidney slices prepared for microangiography were undamaged and available for histochemical processing. Thus, the microvascularity was correlated with the histologic appearance of the renal tissues.
Epidemiologie aspects of bovine anaplasmosis in semiarid range conditions of south central Idaho
Authors: Maas J. , Lincoln S. D. , Coan M. E. , Kuttler K. L. , Zaugg J. L. , Stiller D.
Published: February 2025

The prevalance of Anaplasma marginale-infected cows, as determined by use of the modified rapid card agglutination (mrca) test, was measured during a 4-year period (1980-1983). The prevalence of A marginale-infected cows, defined as positive reactors on the mrca test, remained constant (31%-37%). The apparent incidence of A marginale transmission to susceptible cows was approximately 7% from 1980 to 1981, 8% from 1981 to 1982, and no transmission from 1982 to 1983. The occasional mrca-positive cow became negative on the mrca test, and 1 cow was determined to be free of A marginale infection by subinoculation of 100 ml of the cow's blood into a susceptible, splenectomized calf. Dermacentor andersoni, a known vector of A marginale, was often found on the cattle and in their environment. However, A marginale was not transmitted to susceptible, splenectomized calves, using collected ticks. Of 56 calves born to mrca-positive cows, 82% were mrca-positive within the first 3 months of life. These calves converted to mrca-negative status and were determined to be free of A marginale infection by subinoculation of their blood into susceptible, splenectomized calves, indicating the passive transfer of colostral antibodies.
Eosinophilie myositis and muscular sarcocystosis in the carcasses of slaughtered cattle and lambs
Authors: Jensen Rue , Alexander A. F. , Dahlgren R. R. , Jolley W. R. , Marquardt W. C. , Flack D. E. , Bennett B. W. , Cox M. F. , Harris C. W. , Hoffmann G. A. , Troutman R. S. , Hoff R. L. , Jones R. L. , Collins J. K. , Hamar D. W. , Cravans R. L.
Published: February 2025

Fifty-three bovine and 7 ovine carcasses condemned for having eosinophilic myositis were evaluated. Four (7.3%) of the bovine carcasses had a few, large local lesions in skeletal muscles (category A), and 49 (92.7%) of the bovine carcasses and 7 (100%) of the ovine carcasses had multiple, small, disseminated lesions in tongue, esophagus, heart, diaphragm, or skeletal muscles (category B). Tissue from carcasses of category B were evaluated for bacteria, viruses, selenium, and pathologic changes. Pathogenic bacteria and viruses were not isolated and selenium concentrations were normal. In category B, all carcasses had granulomas; of the 49 bovine carcasses and 7 ovine carcasses, 38 (77.6%) and 7 (100%), respectively, had one or more granulomas with opened dead sarcocysts. The data indicated that opened sarcocysts killed the host myocyte and adjacent myocytes and stroma, thereby initiating granuloma formation.
Heterotransplantation of equine carcinoma cells in athymic (nude) mice
Authors: Pardini Lani L. , Aaronson Laura M. , Hering Pamela L. , Pardini Ronald S.
Published: February 2025

Nondifferentiated equine carcinoma cells from a primary lesion were implanted subcutaneously in athymic (nude) mice. The cells were implanted at 2 sites each in 3 mice. At 1 of the 6 inoculation sites, a tumor developed, which invaded surrounding tissues, as shown by histopathologic examination. Karyotype analysis verified that the tumor was of equine origin. Cells from this tumor were serially heterotransplanted 20 times without change in growth rate. Once established in nude mice, this equine carcinoma cell line was stored cryogenically and then was successfully reimplanted into nude mice. All of the implants developed into tumors, over 20 generations. Preliminary screening of antineoplastic drugs indicated that this tumor line is sensitive to cyclophosphamide. Because of its ease of handling and high reimplantation efficiency, this tumor line should prove useful in equine cancer research.
3-Acetyl-4″-isovaleryl tylosin for prevention of swine dysentery
Authors: Jacks Thomas M. , Judith Frederick R. , Feighner Scott D. , Likoff Robert O.
Published: February 2025

The 21 field isolates of Treponema hyodysenteriae which were tested were sensitive to 3-acetyl-4″-isovaleryl tylosin (aiv); the minimal inhibitory concentration was 0.25 to 16 μg/ml.

3-Acetyl-4″-isovaleryl tylosin administered prophylactically to pigs at concentrations of 5 to 100 mg/kg of feed and tylosin at 110 mg/kg of feed for 28 or 31 days prevented swine dysentery induced by tylosin-sensitive T hyodysenteriae strain SQ2; 15 nonmedicated, inoculated control pigs had bloody diarrhea, and 9 pigs died.

In 2 additional trials, aiv administered prophylactically for 28 days at 55 or 110 mg/kg of feed prevented swine dysentery induced by tylosin-insensitive T hyodysenteriae strain B204. All of the inoculated principal pigs medicated with aiv at 55 or 110 mg/kg of feed or carbadox at 55 mg/kg of feed and the noninoculated sentinel pigs for each group had solid feces throughout the 56-day trial. In the nonmedicated, inoculated control groups, bloody diarrhea began at 4 to 5 days after inoculation was done, and 9 of 10 principal pigs and 6 of 9 sentinel pigs had dysentery; 2 pigs died. In the groups medicated with aiv at 27.5 or 5.5 mg/kg of feed, all 5 principal pigs and 3 or 4 sentinel pigs in each group had dysentery; 3 or 4 pigs in each group died. In the group medicated with tylosin at 110 mg/kg of feed, 7 of 10 principal pigs and all 9 sentinel pigs had dysentery; 1 pig died. Treponema hyodysenteriae was not isolated from the inoculated groups medicated with aiv at 55 or 110 mg/kg of feed or with carbadox at 55 mg/kg of feed, but was repeatedly isolated from all other inoculated groups.
Identification of bovine carriers of Moraxella bovis by comparative cultural examinations of ocular and nasal secretions
Authors: Pugh G. W. , McDonald T. J.
Published: February 2025

The carrier state of Moraxella bovis was investigated, using bacteriologic examinations of ocular and nasal secretions from cattle under experimental and natural conditions of exposure and management. Moraxella bovis was isolated throughout the year from the ocular and nasal secretions of cattle naturally affected with infectious bovine keratoconjunctivitis. There was also 1 case of nasal transmission of M bovis without isolation of M bovis from ocular secretions and 1 case of M bovis isolation from the vagina of a calf contracted by contact with a calf affected with infectious bovine keratoconjunctivitis. The frequency of isolations and duration of infections, as determined by examination of ocular and nasal secretions, indicated that these secretions were comparable in the identification of M bovis carriers. The increased cultural isolations of M bovis from nasal secretions after shipment relative to the number of isolations before shipment indicated that shipment may serve as a stress factor causing an increase in the number of carriers.
Antibiotic susceptibilities of swine Salmonella isolants from 1979 to 1983
Authors: Mills Kenneth W. , Kelly Barbara L.
Published: February 2025

Two hundred seventy-seven Salmonella (27 serotypes) were isolated from Kansas swine over a 5-year period (1979 to 1983). Salmonella cholerae-suis was the predominant isolant from all tissues and made up 94.4% of the Salmonella isolants from the lungs. The percentage of Salmonella isolants susceptible to various antimicrobial agents was determined. The percentage of Salmonella susceptible to carbadox decreased from 1980 to 1983.
Cardiopulmonary effects of continuous intravenous infusion of guaifenesin, ketamine, and xylazine in ponies
Authors: Greene S. A. , Thurmon J. C. , Tranquilli W. J. , Benson G. J.
Published: February 2025

Eight ponies were anesthetized with a solution containing 50 mg of guaifenesin, 1 mg of ketamine, and 0.5 mg of xylazine·ml−1 of 5% dextrose in water. Anesthesia was induced by iv injection (1.1 ml · kg−1), followed by continuous iv infusion at 2.75 ml · kg−1 · hr−1. Heart rate, rate-pressure product, mean pulmonary artery pressure, and standard bicarbonate were not significantly changed throughout the study. Systolic, diastolic, and mean arterial pressures and left ventricular stroke work index were significantly decreased at 5 and 15 minutes after a bolus of the anesthetic solution was injected. Systolic blood pressure returned to within the base-line range at 30 minutes, but diastolic and mean arterial pressures were significantly decreased throughout the study. Cardiac index and arterial pH were decreased at 5 minutes only. Systemic vascular resistance was significantly decreased 60 minutes after bolus injection was given. Hypoventilation, as indicated by increased PaCO2, occurred 5 minutes after bolus injection was given.
Effects of dose and duration of therapy on gentamicin tissue residues in sheep
Authors: Brown Scott Anthony , Coppoc Gordon L. , Riviere J. Edmond
Published: February 2025

The effects of different doses and dosage regimens on gentamicin pharmacokinetics and tissue residues were determined. Five groups of 12 sheep each were given gentamicin im: group I, 2 mg of gentamicin sulfate/kg once; group II, 6 mg/kg once; group III, 18 mg/kg once; group IV, 6 mg/kg every 24 hours for 3 doses; and group V, 2 mg/kg every 8 hours for 9 doses. Serum concentrations were determined serially until sheep were killed and necropsied. Three sheep from each group were killed at 1, 4, 8, and 12 days after the last dose was administered. Renal cortex, renal medulla, liver, spleen, lung, skeletal muscle, and skeletal muscle at the injection site were assayed for gentamicin. An exponential equation was fitted to the serum concentrations, and various pharmacokinetic variables were determined. Serum clearance tended to increase as the single dose increased (P = 0.0588). Steadystate volume of distribution increased as the single dose was increased (P < 0.05). Renal cortex contained the highest concentration of gentamicin which decreased in a biexponential manner. Concentrations in all tissues, except the injection site, were dependent upon the amount of the total dose, not the size of the injected dose (P < 0.05). Concentrations at the injection site were up to 29 μg/g of tissue at 1 day after the last dose was given and were dependent upon the amount of total dose from multiple injections, not on the amount of each injected dose (P < 0.05). These results indicated that tissue residues increased as the total dose of gentamicin was increased or as the duration of gentamicin therapy was increased. Furthermore, the injection site contained substantial amounts of gentamicin at 1 day after the last dose was given.
Effect of the injection site on the pharmacokinetics of procaine penicillin G in horses
Authors: Firth E. C. , Nouws J. F. M. , Driessens F. , Schmaetz P. , Peperkamp K. , Klein W. R.
Published: February 2025

The plasma penicillin concentrations were determined in 5 horses given an iv injection of sodium penicillin G; plasma penicillin concentrations were also determined in a crossover experiment, where animals were given procaine penicillin G subcutaneously at 1 site and im at 4 sites. The mean penicillin plasma peak concentration and bioavailability were highest after the drug was injected in the neck and biceps musculature. Injections in the gluteal muscle and in the subcutaneous sites resulted in similar, but lower, more persistent penicillin plasma concentrations and a lower bioavailability than were obtained with injection in the neck and biceps musculature. The pharmacokinetic data obtained after penicillin was administered via the pectoral muscle route exhibited an intermediate position. Therapeutic implications of the routes of administration with respect to hemolytic streptococcal infections are discussed.
Attempted transmission of Ehrlichia risticii by field-captured Dermacentor variabilis (Acari: Ixodidae)
Authors: Schmidtmann E. T. , Robl M. G. , Carroll J. F.
Published: February 2025

The capability of field-collected American dog ticks, Dermacentor variabilis, to infect horses with Ehrlichia risticii, causative agent of Potomac horse fever (phf), was examined by allowing adult ticks collected from horse farms with a history of phf to feed on susceptible horses. More than 500 male and female ticks attached and fed on 3 test horses; however, no clinical or serologic evidence of phf was observed in treated or control horses. All horses were challenge exposed with E risticii-infective blood by inoculation at 60 to 65 days after ticks fed, and all developed clinical phf with subsequent seroconversion. The data, therefore, indicated that adult D variabilis, a common parasite of horses on Maryland premises where phf is enzootic, may not serve as a vector of E risticii.
Eructation of gas through the gastroesophageal sphincter before and after truncal vagotomy in dogs
Authors: Strombeck Donald R. , Harrold Doris , Ferrier William
Published: February 2025

The function of the gastroesophageal sphincter (ges) to eructate gas before and after vagotomy was investigated in conscious, fed dogs. Gastric and ges pressures were measured in 5 dogs, using a perfused 4-lumen catheter with a Dent sleeve. To induce eructation, nitrogen gas was insufflated (440 ml/min) into the stomach through 1 channel of the catheter. After base-line studies were completed on each dog, bilateral truncal vagotomy was performed 5 cm cranial to the diaphragm. Mean (± se) ges pressure was 51.5 ± 1 mm of Hg before vagotomy and 28 ± 1.7 mm of Hg after vagotomy (P < 0.001). Mean gastric contraction rates were the same, 4.91 ± 0.11/min and 4.78 ± 0.06/min in dogs before and after vagotomy, respectively.

During insufflation, gastric pressures increased to 11.8 ± 0.7 mm of Hg before eructation in dogs before vagotomy and to 18.4 ± 0.8 mm of Hg in dogs after vagotomy (P < 0.001). Eructation occurred at intervals of 1.79 ± 0.09 minutes before vagotomy and 5.71 ± 0.41 minutes after vagotomy (P < 0.001). Atropine resulted in an interval of 1.98 ± 0.18 minutes before vagotomy. Eructation was not seen in 2 dogs after vagotomy and was sometimes not seen in the 3 others. Gastroesophageal sphincter pressure in dogs before vagotomy began to decrease 4.5 ± 0.2 s before the ges-pressure gradient disappeared, and ges pressure remained there for 5.3 ± 0.3 s before the gradient began to return. Vagotomy resulted in the appearance of phasic contractions (at a rate the same as gastric contractions) of the ges and the terminal few centimeters of esophagus during insufflation. Seemingly, vagal denervation of the ges may result in its motor activity being influenced by the gastric pacemaker.
Ultrastructural changes in inherited cardiac calcinosis of DBA/2 mice
Authors: Van Vleet John F. , Ferrans Victor J.
Published: February 2025

Cardiac dystrophic calcinosis, an inherited condition in DBA/2 mice, produced extensive calcific lesions in the right ventricular myoepicardium of affected mice. The morphogenesis of the cardiac alterations was evaluated by microscopic and ultrastructural studies. The initial event was necrosis and mineralization of subepicardial myocytes. Mineral deposits were seen as dense granular and spicular deposits in (i) mitochondria only, (ii) mitochondria and adjacent sarcoplasm, or (iii) the entire sarcoplasm in necrotic myocytes. In mature myoepicardial calcific lesions, the remnants of necrotic myocytes were seen as scattered dense masses of mineralized debris with surrounding fibroplasia and occasional macrophages and giant cells. Male weanling DBA/2 mice (n = 135) were fed either a commercial diet adequate in selenium-vitamin E (Se-E) content, or a basal semipurified Se-E-deficient diet with or without silver acetate for 15, 20 or 25 weeks. Cardiac calcinosis severity seemed to increase in mice which developed concurrent Se-E deficiency. Cardiac calcinosis in the DBA/2 mouse is a useful model of cardiac calcification.
Investigation into the use of narcotic antagonists in the treatment of a stereotypic behavior pattern (crib-biting) in the horse
Authors: Dodman Nicholas H. , Shuster Louis , Court Michael H. , Dixon Ross
Published: February 2025

Crib-biting in horses is a repetitive behavior pattern which may involve the activation of both narcotic receptors and dopamine receptors in the cns. Crib-biting frequency, determined in 7 nontreated horses under controlled conditions, was usually linear for many hours and ranged from 0.3 to 14.9 bites/min. Intravenous or im injections of narcotic antagonists decreased these rates to almost zero by about 20 minutes after the injection was given. The duration of the response to a single injection ranged from 20 minutes for naloxone to 4 hours or more for nalmefene and diprenorphine. Effective doses were 0.02 to 0.04 mg of naloxone/kg, 0.04 mg of naltrexone/kg, 0.08 mg of nalmefene/kg, and 0.02 to 0.03 mg of diprenorphine/kg. Crib-biting could be prevented completely for up to a week by continuous infusion of 5 to 10 mg of nalmefene/hr. Crib-biting resumed when the infusion was discontinued, and plasma nalmefene concentrations decreased to below 5 ng/ml. Doses of nalmefene as large as 0.4 mg/kg, iv, produced only minor side effects. These side effects included some passage of semifluid fecal material, intermittent penile relaxation, and mild sedation. Treated horses responded normally to external stimuli, retained their appetites, and performed appropriately when ridden. Sedation wore off during the course of prolonged infusions. Narcotic antagonists may provide a novel and effective treatment of stereotypic behavior disorders.
Distribution and implications of β-endorphin and ACTH-immunoreactive cells in the intermediate lobe of the hypophysis in healthy equids
Authors: Amann John F. , Smith Robin M. , Ganjam V. K. , Paull Willis K. , McClure Robert C. , Green Eleanor M. , Garner Harold E.
Published: February 2025

The distribution of cells that stain positive for β-endorphin and ACTH immunoreactivity was studied in the pars intermedia (pi) of the hypophysis in 3 healthy horses and 2 healthy ponies. Serial sections treated with commercial antibodies generated against β-endorphin or ACTH(l-39) were processed for immunocytochemical studies, using the avidin biotin immunoperoxidase-complex method. Distribution patterns of cells reacting with antibodies were similar in cells from all equids. Cells immunostained for ACTH were numerous and widely distributed in the pi. Cells immunopositive for ACTH probably contain corticotrophin-like intermediate lobe peptide that cross-reacts with antisera to ACTH. Cells immunopositive for β-endorphin were fewer in number and had a more limited distribution in the pi. Most β-endorphin-positive cells were located along the border of the pi adjacent to the lobus nervosus and had abundant eosinophilic cytoplasm when stained with hematoxylin and eosin. Cells with prominent eosinophilic cytoplasm were not common in other areas of the pi. When serial sections were examined, cells that stained positive for β-endorphin immunoreactivity also appeared positive for ACTH.
Chemoprophylaxis of cryptosporidiosis in chickens, using halofuginone, salinomycin, lasalocid, or monensin
Authors: Lindsay David S. , Blagburn Byron L. , Sundermann Christine A. , Ernest James A.
Published: February 2025

Chemoprophylaxis of Cryptosporidium baileyi infections was attempted by feeding 4 groups of chicks diets containing 3 mg of halofuginone/kg of feed, 60 mg of salinomycin/kg, 75 mg of lasalocid/kg, or 110 mg of monensin/kg. Rations were fed 5 days before oral or intratracheal inoculation with oocysts and were continued for 20 days. None of the drugs prevented C baileyi infections. Clinical signs of respiratory tract disease and gross lesions of air-sacculitis were observed in intratracheally inoculated birds in all treatment groups and nonmedicated controls. Orally inoculated birds did not develop clinical signs of infection. Pathogenic bacteria were not isolated from the respiratory tract systems of any chicks. Halofuginone delayed the establishment of infections of the bursa of Fabricius and cloaca, but not of the trachea.
Effects of loperamide hydrochloride on experimental diarrhea and gastrointestinal myoelectrical activity in calves
Authors: Fioramonti Jean , Buéno Lionel
Published: February 2025

The antidiarrheal action of loperamide hydrochloride was tested against diarrhea experimentally induced in calves by intraduodenal infusion of castor oil or hypertonic solution of mannitol. The motility of 4 levels of the digestive tract (abomasum, jejunum, and proximal and spiral loops of the colon) was concomitantly recorded, using an electromyographic technique. Loperamide hydrochloride given per os at 0.4 mg/kg or intraduodenally or subcutaneously at 0.1 mg/kg 1 hour before mannitol or castor oil was given delayed diarrhea. Loperamide hydrochloride given alone orally at a dosage of 0.4 mg/kg did not modify the motility pattern of the digestive tract. Intraduodenally administered loperamide hydrochloride (0.1 mg/kg) increased the frequency of the cyclic activity of the jejunum, whereas subcutaneously administered loperamide hydrochloride at the same dose selectively inhibited the motility of the jejunum. Intraduodenal infusion of mannitol was followed by a disruption of the cyclic activity of the jejunum, and this effect was not antagonized by loperamide hydrochloride, whatever the route of administration. Castor oil infusion was not accompanied with changes in gastrointestinal motility. These results indicate that loperamide hydrochloride is active against an experimentally induced diarrhea in calves and that this action is not mediated through an effect on the digestive motility, at least monitored by this electromyographic technique.