bluuebunny/crossref_metadata_2025 huggingface dataset:
Treatment of clinically normal and cystinuric dogs with 2-mercaptopropionylglycine
Authors: Hoppe Astrid , Denneberg Torsten , Kågedal Bertil
Published: February 2025

In a pharmacokinetic and tolerance study, 2 healthy Beagles were given 13.2 to 39.5 mg of 2-mercaptopropionylglycine (2-mpg)/kg of body weight orally once daily in increasing doses for 3 weeks. A third dog was given 10 mg of 2-mpg/kg of body weight, iv. The drug was well tolerated.

After these initial studies, 15 cystinuric dogs were treated with 2-mpg orally once daily for 5 to 45 months and with sodium bicarbonate for urine alkalinization and fluid diuresis. Pharmacokinetic studies were done in 7 dogs on the third day of oral treatment with 2-mpg. After oral administration of 15.6 to 31.3 of 2-mpg/kg of body weight, maximal serum/plasma concentrations were from 28.6 to 76.3/μmol/L after 1 to 3 hours in 6 cystinuric dogs. The mean urinaiy excretion was 22% (range, 0.3 to 58.9%) of the dose.

Ten of 15 cystinuric dogs had no re-formation of uroliths. Of 4 dogs with uroliths at the beginning of treatment, 3 had total urolith dissolution on continuous treatment. During treatment, further growth of the uroliths was inhibited in one dog, and in another dog with re-formed uroliths, they dissolved. We concluded that 2-mpg is well tolerated and promising for treatment of cystinuric dogs, but the pharmacokinetic studies should be expanded to include different dosage regimens, and results of long-term treatment should be evaluated.

Our recommendations for treatment of dogs with cystine uroliths include surgical intervention if the dog has urethral obstruction or has dysuria. If the dog's urethra is not obstructed, a combination of urine alkalinization, fluid diuresis, and oral treatment with 2-mpg at a daily dosage of 30 to 40 mg/kg of body weight will cause urolith dissolution in most instances. Also, these measures are effective in preventing urolith reformation.
Plasma luteinizing hormone and progesterone concentrations in goats with estrous cycles of normal or short duration after prostaglandin F2α administration during diestrus or pregnancy
Authors: Bretzlaff K. N. , Weston P. G. , Hixon J. E. , Ott R. S.
Published: February 2025

Plasma luteinizing hormone (lh) and progesterone concentrations were compared in does experiencing short-duration estrous cycles and in does with estrous cycles of normal duration. The short-duration estrous cycles were observed immediately after induction of abortion in pregnant does by use of prostaglandin (pg) F2α. Intramuscular administration of 5 mg of pgf2α was accomplished in 8 does that were 52 to 63 days into gestation and in 9 cycling does at 7 to 10 days after estrus. In both groups, the mean plasma concentration of progesterone decreased from a luteal phase concentration immediately before to < 1 ng/ml by 24 hours after pgf2α administration. Of the 8 does that aborted, 6 experienced short-duration estrous cycles, and 4 of these 6 had an lh surge during the time of blood sample collection. The mean time from pgf2α administration to the lh surge was significantly (P < 0.05) longer in does with short-duration estrous cycles (71 hours) than that in does with estrous cycles of normal duration (58 hours). The mean area under the lh concentration curve was significantly (P < 0.005) less for does with short-duration estrous cycles. Short-duration estrous cycles were associated with delayed preovulatory lh surges of reduced magnitude.
Scintigraphic imaging of technetium 99m-labeled neutrophils in the dog
Authors: Moon M. L. , Hinkle G. N. , Krakowka G. S.
Published: February 2025

Autologous canine neutrophils were labeled with technetium 99m and reinjected in 7 dogs with experimentally induced focal abscesses to determine the ability of scintigraphy to localize a focus of sepsis (abscess). Good localization of labeled cells in an abscess was achieved; however, a large portion of the technetium 99m eluted from the neutrophils.
Efficacy of ivermectin in the oral paste formulation against naturally acquired adult and larval stages of Parascaris equorum in pony foals
Authors: French D. D. , Klei T. R. , Taylor H. W. , Chapman M. R. , Wright F. R.
Published: February 2025

The efficacy of ivermectin in oral paste formulation at a dosage of 200 μg/kg of body weight was tested against naturally acquired larval and adult stages of Parascaris equorum, in a controlled study. Twenty infected pony foals 18 to 27 weeks of age were randomly allocated to 2 groups of 10 each and were placed in dry lots. Foals in 1 group were given ivermectin on day 0. Necropsies and parasite recoveries from small intestines and lung tissues were performed on 5 foals in each group at 2 weeks after treatment (wat) and on the remaining foals at 5 wat. Ivermectin was 100% effective against adult P equorum. At 2 wat, ivermectin was 100% effective against lung larval stages and 91% effective against intestinal larvae of P equorum. Efficacy of ivermectin against all intestinal stages was 93%. Intestinal and lung larval populations were similar in ivermectin-treated and nontreated foals at 5 wat, indicating that the foals had become reinfected from the contaminated drylots, with larvae repopulating in the tissues 2 to 5 wat. Apparent increases in severity of lymphoproliferative and inflammatory tissue reactions were observed histologically in lung and liver tissues of treated foals. Clear differences in clinical conditions between foals in treated and nontreated groups were not observed. However, weight gains in foals were greatest after treatment.
Efficacy of oxfendazole against inhibited larvae of Ostertagia ostertagi acquired by calves in the spring
Authors: Miller James E. , Hembry F. Glen , Kearney Michael T.
Published: February 2025

During the spring of 1985, 40 calves grazed pastures known to have high numbers of spring inhibition-prone, infective Ostertagia ostertagi larvae. Calves were removed from pasture and placed in outdoor pens with concrete floors from 10 days prior to treatment until necropsy 14 days after treatment. Ten calves were allocated to each of 4 treatment groups, and oxfendazole was administered to each group by intraruminal injection at dosages of 0, 2.25, 4.5, and 6.75 mg/kg of body weight. Efficacies ≥ 94.6% were achieved at dosages of 4.5 and 6.75 mg/kg against adult Ostertagia spp, Trichostrongylus spp, Haemonchus placei, Cooperia punctata, Bunostomum phlebotomum, Oesophagostomum radiatum, and Dictyocaulus viviparus. Efficacy against inhibited larvae of O ostertagi was variable, with the highest efficacy (90.2%) attained at a dosage of 6.75 mg/kg.
Hereditary nonspherocytic hemolytic anemia in Beagles
Authors: Maggio-Price Lillian , Emerson Carol L. , Hinds Thomas R. , Vincenzi Frank F. , Hammond William R.
Published: February 2025

Three Beagles with chronic anemia and reticulocytosis were studied. The dogs originated from a large breeding colony and appeared clinically normal with the exception of splenomegaly. The pcv ranged from 30 to 39% (normal, 46 to 56%), with reticulocyte indices of 2.3 to 9.9. Red blood cells were morphologically normal, and examination of marrow aspirates revealed erythroid hyperplasia. Shortened chromium-51 rbc life-spans (7.2 to 15.4 days in anemic dogs; 22.2 to 25.2 days in control dogs) documented a hemolytic anemia. Acquired causes of hemolytic anemia were ruled out. Red blood cells had normal glycolytic enzyme activities, no evidence of unstable or abnormal hemoglobin, and had altered osmotic fragility curves. The breeding of 2 anemic dogs resulted in offspring with anemia and reticulocytosis. Polyacrylamide gel electrophoresis revealed no abnormalities in rbc membrane cytoskeletal proteins in all anemic adult dogs and in 3 offspring.
Evaluation of heat-sensitive, neutrophil-toxic, and hemolytic activity of Haemophilus (Actinobacillus) pleuropneumoniae
Authors: Rosendal S. , Devenish J. , MacInnes J. I. , Lumsden J. H. , Watson S. , Xun H.
Published: February 2025

Cytotoxic and hemolytic activity of Haemophilus (Actinobacillus) pleuropneumoniae serotype 1 strain CM5 was investigated because of the potential role as a virulence determinant. Viable bacteria were toxic for porcine and bovine neutrophils, whereas bacteria killed by heat treatment at 60 C for 1 hour were not. Similarly, bacteria-free culture supernatant was cytotoxic and hemolytic in assays that used porcine neutrophils and erythrocytes, whereas supernatant treated at 60 C for 1 hour had no activity. Erythrocytes from various species were susceptible to the hemolytic activity of bacteria-free culture supernatant, with ovine and bovine erythrocytes being most sensitive. The neutrophil-toxic and hemolytic activity of bacteria-free culture supernatant was inhibited by cholesterol and oxygen and abolished after trypsin digestion. The neutrophil-toxic and hemolytic activity was preserved during storage at or < 4 C, but was lost rapidly at 56 C or 80 C.

Neutralizing antibodies were demonstrated in serum of pigs and rabbits immunized with 10-fold concentrated culture supernatant of strain CM5 and in field pigs that had recovered from natural infection with H pleuropneumoniae serotype 1.

Bacteria-free culture supernatants of 18 strains, including H pleuropneumoniae serotypes 1 through 10, Actinobacillus suis, and Haemophilus taxon minor group, were tested for heat-sensitive, neutrophil-toxic, and hemolytic activity. Fifteen strains were neutrophil toxic, but only 10 of these were hemolytic. Haemophilus pleuropneumoniae, serotype 1, strain VLS557; serotype 5, strain K17; and Haemophilus taxon minor group strain 33PN were neither cytotoxic nor hemolytic.
Pharmacokinetics of thiamylal in cats
Authors: Wertz E. M. , Benson G. J. , Thurmon J. C. , Tranquilli W. J. , Davis L. E. , Koritz G. D.
Published: February 2025

Pharmacokinetics of thiamylal were determined after 13.2 mg of thiamylal/kg of body weight was administered iv to 6 healthy cats. Blood samples were obtained for 12 hours. Disposition of thiamylal best conformed to 2 multicompartmental models, a 2-compartment (n = 1) and a 3-compartment (n = 5) open pharmacokinetic model. The pharmacokinetic values were calculated for the overall best-fitted model, a mixed 2- and 3-compartmental model. The first or rapid distribution half-life was 1.91 minutes and a second, or slower, distribution half-life was 26.51 minutes. The elimination half-life was 14.34 hours. The apparent volume of distribution was 3.61 ± 1.8463 L/kg, whereas the apparent volume of the central compartment was 0.46 ± 0.2034 L/kg, and the total clearance was 0.135 ± 0.0616 L/kg/h.
Survival of rough and smooth strains of Brucella abortus in bovine mammary gland macrophages
Authors: Harmon Barry G. , Adams L. Garry , Frey Miles
Published: February 2025

Chronic bovine brucellosis is characterized by persistent infection of the mammary gland. The interaction of live Brucella abortus with bovine mammary gland macrophages was studied in vitro. Opsonization of smooth B abortus strain 2308 and rough strain 45/20 was required for phagocytosis by mammary gland macrophages. When opsonized with specific antiserum, strains 2308 and 45/20 stimulated a considerable oxidative burst when phagocytized by mammary gland macrophages. Intracellular survival rates for strain 2308 were significantly higher than those for strain 45/20. After being phagocytized, B abortus localized in phagosomes and phagolysosomes of mammary gland macrophages.
Muscle hemodynamics in hereditary myopathy of Labrador Retrievers
Authors: Amann John F. , Laughlin M. Harold , Korthuis Ronald J.
Published: February 2025

Morphologic lesions seen in six 8-month-old Labrador Retrievers with hereditary myopathy were predominantly small- and large-group atrophy of muscle cells of all fiber types. The dogs were intolerant of exercise and fatigued rapidly. An isolated gracilis muscle preparation was used to study the hemodynamic features of the microvasculature. Isogravimetric capillary pressure as well as arterial and venous pressures in the isolated gracilis muscle preparation obtained during maximal vasodilatation were within the range reported for healthy, mixed-breed dogs, as were precapillary, postcapillary, and total vascular resistances. Capillary filtration and osmotic reflection coefficients were not different from those reported in other studies on healthy dogs. All measurements and calculations were repeated during reperfusion, subsequent to a 4-hour period of global ischemia. Postischemic vascular responses were similar to the pattern previously reported in healthy dogs. These studies did not support the hypothesis of a vascular defect as a cause of hereditary myopathy in Labrador Retrievers.
Method to create and maintain the patency of the bovine mammary papilla
Authors: Nassef Mahmoud T. , Coy C. H. , Watson Gary L.
Published: February 2025

The patency of mammary papillae was reestablished after surgically induced injury. Perforated prosthetic tubes with affixed Dacron tubing or Teflon strips were implanted in 18 abraded papillae of lactating dairy cows and were secured with sutures. Wound healing was assessed by palpation and visual inspection. All wounds, with one exception, healed by first intention. Machine milking, reinstituted on day 5 after surgery, caused no apparent discomfort. Grossly and histopathologically, all implants stimulated a variable degree of mucosal metaplasia and hyperplasia. Only implants with Teflon strips became anchored by fibrotic invasion. Mastitis, tube migration, and milk fistulas were complications of the procedure.
Arachidonic acid metabolites produced by bovine alveolar macrophages
Authors: O'Sullivan M. G. , Dobrowsky R. T. , Fleisher L. N. , Olson N. C. , Brown T. T.
Published: February 2025

Bovine alveolar macrophages, obtained by bronchoalveolar lavage, were labeled with tritiated arachidonic acid. The cells were stimulated with calcium ionophore A23187, and the radiolabeled arachidonic acid metabolites that were released were identified by reverse-phase high-performance liquid chromatography. Leukotriene B4 and 5-hydroxyeicosatetraenoic acid were consistently observed. The lipoxygenase inhibitor, nordihydroguaiaretic acid, blocked production of these metabolites. The cyclooxygenase products, prostaglandin F2α and thromboxane B2, were observed infrequently in comparison with leukotriene B4 and 5-hydroxyeicosatetraenoic acid.
Survey of serum IgA, IgG, and IgM concentrations in a large Beagle population in which IgA deficiency had been identified
Authors: Glickman Lawrence T. , Shofer Frances S. , Payton Alice J. , Laster Larry L. , Felsburg Peter J.
Published: February 2025

Concentrations of serum IgA, IgG, and IgM were determined for 829 adult Beagles from a commercial kennel in which several IgA-deficient dogs had been identified previously (index kennel). These values were compared with measurements of 100 adult dogs from another Beagle kennel (control kennel). After adjustment for differences in the ages and gender of the dogs, dogs from the index kennel had significantly (P < 0.0001) lower IgA concentrations (mean, 46 mg/dl) than dogs from the control kennel (mean, 68 mg/dl). Regardless of kennel, males had significantly (P < 0.01) higher IgA concentrations than did females. Dogs in the control kennel had significantly (P < 0.04) higher IgG concentrations (mean, 2,649 mg/dl) than did dogs in the index kennel (mean, 2,478 mg/dl), and female dogs in the control kennel had significantly (P < 0.05) higher IgM concentrations (mean, 189 mg/dl) than dogs of either sex in the index kennel (mean, 162 mg/dl) or male dogs in the control kennel (mean, 163 mg/dl). For both sexes, concentrations of IgA, IgG, and IgM increased with age.
Multiple regression analysis, using body size and cardiac cycle length, in predicting echocardiography variables in dogs
Authors: Jacobs Gilbert , Mahjoob Kooros
Published: February 2025

A significant (P < 0.0001) positive correlation was demonstrated between left ventricular internal chamber dimension in diastole or systole and body weight, body surface area, cycle length, and the square root of cycle length. On the basis of adjusted coefficients of determination, multiple regression analysis, using body weight or body surface area and cycle length or the square root of cycle length, was superior to separate simple regression with these variables in accounting for variations in left ventricular internal chamber dimensions.

Shortening fraction had a significant (P < 0.0001) negative correlation and left ventricular free wall measurements had a significant (P < 0.0001) positive correlation to body weight and body surface area. For these echocardiographic variables, correlation to the square root of cycle length was insignificant (P > 0.05), and a multiple regression model was not helpful in developing confidence intervals. Septal wall measurements were not correlated with body weight, body surface area, cycle length, or the square root of cycle length.
Anosmia associated with canine distemper
Authors: Myers L. J. , Hanrahan L. A. , Swango L. J. , Nusbaum K. E.
Published: February 2025

The sense of smell in dogs infected with canine distemper virus (cdv) was examined by use of eeg olfactometry, behavioral olfactometry, and electro-olfactography. Infection with cdv was confirmed by a direct immunofluorescence technique in 8 active cases and was suggested by clinical history compatible with canine distemper 10 to 26 weeks earlier in 6 cases. Pathologic alterations of the olfactory mucosa in 3 clinically affected dogs was examined by light microscopy.

Infection with cdv was found to be associated with anosmia and lack of recorded responses on electro-olfactogram in 8 of 8 dogs with clinical signs of acute distemper from naturally acquired infections. Anosmia was found in 5 of 6 dogs that had recovered from acute distemper 10 to 26 weeks earlier. The sixth dog had hyposmia, with abnormalities on the electro-olfactogram. Histologic examination was not performed on the 6 dogs that had recovered. Histologic lesions observed at necropsy in 3 dogs that had had clinical signs of acute distemper were those of subacute purulent rhinitis and atrophy of the olfactory epithelium.

Altered olfactory function could be explained by mucopurulent exudate blocking odors from olfactory receptors in the acutely affected dogs, but alteration of olfactory function in the dogs that had recovered without clinical evidence of rhinitis could not be explained.
Kinetics and kinematics of the equine hind limb: In vivo tendon strain and joint kinematics
Authors: Riemersma Dirk J. , van den Bogert Anton J. , Schamhardt Henk C. , Hartman Wrister
Published: February 2025

Strains of the suspensory ligament and deep digital flexor, superficial digital flexor, and long digital extensor tendons in the equine (pony) hind limb were recorded in vivo, using implanted strain gauges consisting of silicone rubber tubes filled with mercury. The relationship between strain gauge signals and tendon strains was obtained from tension-strain tests performed on isolated tendons after death of the ponies. During normal walking, maximal tendon strain (elongation over initial length, relative to the length of the structures at first ground contact) was 3.1% in the suspensory ligament and 3.4%, 2.3%, and 0.3% in the deep digital flexor, the superficial digital flexor, and the long digital extensor tendons, respectively.

Changes (that occurred during walking) in the distance from origin to insertion of these musculotendinous structures were computed from limb geometric configuration and limb conformation. Maximal increase in origin to insertion length was 3.1% in the suspensory ligament and 2%, 1.6%, and 1.5% in the deep digital flexor, superficial digital flexor, and long digital extensor musculotendinous structures, respectively. The differences in strain, comparing the entire musculotendinous structure and its tendon, were explained by muscular contraction or relaxation.
Neuromuscular pedicle graft for restoration of arytenoid abductor function in dogs with experimentally induced laryngeal hemiplegia
Authors: Greenfield C. L. , Walshaw R. , Kumar K. , Lowrie C. T. , Derksen F. J.
Published: February 2025

Left laryngeal hemiplegia was induced by resection of the left recurrent laryngeal nerve in 12 dogs. A neuromuscular pedicle graft formed from the first cervical nerve and sternothyroideus muscle was transplanted after 1 week to the denervated cricoarytenoideus dorsalis muscle in 8 dogs. The remaining 4 dogs served as controls. Left arytenoid abduction was blindly evaluated by laryngoscopy with video photography at time 0, at 1 week, and at 19 weeks in all dogs. At 19 weeks, biopsy specimens of the left cricoarytenoideus dorsalis muscle and the neuromuscular pedicle were taken from 4 of the treatment dogs, and biopsy specimens of the left cricoarytenoideus dorsalis muscle were taken from the 4 control dogs. All biopsy specimens were blindly evaluated by histologic and histochemical examination. At 36 to 44 weeks, the remaining 4 treatment dogs, from which biopsy specimens had not been taken, were reevaluated by use of laryngoscopy with video photography.

Complications and difficulties encountered during surgery included hemorrhage in the area of the cricoarytenoideus dorsalis muscle, location of a branch of the first cervical nerve that was long enough to prevent tension at the graft site, orientation of the muscle pedicle in the cricoarytenoideus dorsalis muscle without the use of an operating microscope, and preservation of the terminal portion of the first cervical nerve while forming the neuromuscular pedicle.

Results of the arytenoid movement evaluations revealed improvement in arytenoid abductor function in the treatment group, compared with that in the control group at 19 weeks. Arytenoid abduction in the treatment group at this time, however, was still significantly decreased (P < 0.05), compared with presurgical movement evaluations. Arytenoid abductor function continued to improve until it was statistically indistinguishable (P ≥ 0.05) from presurgical abduction at 36 to 44 weeks. Results of examination of biopsy specimens (neurogenic atrophy, evidence of reinnervation, or histologically normal muscle) were compatible with arytenoid movement evaluations in most of the treatment and control dogs.
Hypotension and cutaneous reactions associated with intravenous administration of etoposide in the dog
Authors: Ogilvie Gregory K. , Cockburn Cathy A. , Tranquilli W. J. , Reschke Robert W. , Weigel Ronald M.
Published: February 2025

A study was undertaken to determine the pressor and toxic effects of etoposide, an antineoplastic agent, when administered iv in 0.9% sodium chloride solution (0.4 mg of etoposide/ml) over a 30-minute period to dogs at a dosage of 40 mg/m2 of body surface. On day 1, 6 adult German Shorthaired Pointers were anesthetized with halothane, and blood pressures were measured via a femoral artery catheter before, during, and after the etoposide was administered. Systolic, diastolic, and mean blood pressures of each dog increased significantly (P < 0.01) within 30 minutes after initiation of etoposide infusion. On day 3, when the dogs were not anesthetized, etoposide was again administered to each dog, using the same dosage. Each dog developed a moderate to severe cutaneous reaction characterized by moderate to severe pruritus, urticaria, and swelling of the head and extremities that began during the second infusion of etoposide. These same cutaneous reactions were seen on day 30, when etoposide was administered to 3 of the previously treated dogs and 2 previously untreated Beagles. We concluded that the administration of the commercial preparation of etoposide is likely to cause a significant reduction in blood pressure of anesthetized dogs, and that the drug is likely to induce a moderate to severe cutaneous reaction when administered to unanesthetized dogs.
Light microscopic study of granulocytes of Pygoscelid penguins (Pygoscelis adeliae) of Antarctica
Authors: Zinsmeister Virginia A. Paris
Published: February 2025

Morphologic features of heterophils, eosinophils, and basophils of wild adult Pygoscelid penguins (Pygoscelis adeliae; 1 male, 4 females) of Antarctica were studied. Granulocytes were described on the basis of analysis of stained blood films and of 0.5-μm sections of centrifuged resin-embedded blood. Morphometric analysis of granulocytes included average cell diameter, cell shape, and nuclear configuration as well as the number, size, and shape of intracytoplasmic granules.

Large round heterophils were the most prevalent granulocyte and possessed numerous rod- and spindle-shaped granules and a polymorphous nucleus. The second most prevalent granulocyte was the eosinophil. These eosinophils contained a bilobed nucleus and an average of 29.52 homogeneous granules/cell. The smallest and least encountered granulocyte was the basophil. Basophils possessed a single eccentric nucleus surrounded by round metachromatic granules (12.20 granules/cell) of varying size.
Specific serodiagnosis of canine leishmaniasis by indirect immunofluorescence, indirect hemagglutination, and counterimmunoelectrophoresis
Authors: Mancianti Francesca , Meciani Nicola
Published: February 2025

The increased prevalence of leishmaniasis in dogs in Mediterranean countries has necessitated use of a reliable specific method of immunodiagnosis. Research was carried out on 88 dogs, among which were 26 with severe clinical leishmaniasis (group A), 15 with mild signs of disease (group B), and 11 without signs of disease (group C); in addition, 15 were healthy (group D) and 21 were affected with various other diseases (group E). Dogs of groups D and E were used as controls. Infection was confirmed by cultural isolation of the parasite.

Serotests that were used included the indirect immune fluorescent (ifat) and indirect hemagglutination (ihat) tests and counterimmunoelectrophoresis (ciep); using these tests, specific antibodies against Leishmania infantum were detected in all 88 dogs. Sensitivity of the ifat was 100% in dogs of groups A, B, and C; for the ihat, it was 65.38%, 60%, and 54.5%, respectively, and for ciep, it was 96.1%, 80%, and 72.7%, respectively. For dogs of groups D and E, specificity of the ifat and ihat was 100%, and for ciep, it was 100% for group-D dogs and 90.5 for group-E dogs. Indirect immunofluorescence appeared to be the most specific and sensitive of the 3 tests.
A method to detect rabbit neutrophil phagocytosis of Pasteurella multocida
Authors: Rush H. G. , Moore K. E.
Published: February 2025

A method was developed to detect neutrophil phagocytosis of bacteria by determining whether neutrophil-associated bacteria were intra- or extracellular. Neutrophils were treated with 8-(N,N-diethylamino)-ocytl-3,4,5-trimethoxybenzoate hydrochloride to inhibit degranulation and, consequently, killing of bacteria. Treated neutrophils and opsonized Pasteurella multocida were combined. Following phagocytosis, the suspensions were centrifuged and the pellets were washed to remove non-cell-associated bacteria. The pellets were resuspended and heparin was added to prevent further phagocytosis. Samples were removed, and the number of viable bacteria was determined by a dilution and plate count technique. Streptomycin, an antibiotic that is poorly taken up by neutrophils, was added to kill extracellular bacteria, and the suspensions were incubated for 20 minutes at 37 C, and samples were removed again and bacterial numbers were determined. Percentage killing of bacteria by streptomycin was calculated. Phagocytosed bacteria were protected from the bactericidal action of streptomycin.
Kinetics of large-scale production of bovine leukocyte interferon, using three viral inducers
Authors: Jacobsen Karen L. , Rockwood Gail A. , Abolhassani Mohsen , Evans Donald L. , Chitwood Sharon W. , Charamella Leigh
Published: February 2025

Kinetics of large-scale production of naturally derived bovine leukocyte interferon (ifn) was investigated using Sendai virus, Newcastle disease virus, and infectious bovine rhinotracheitis virus inducers. Cultures were tested for ifn production every 6 hours for 66 hours. The effect of varying the priming dose of Sendai virus from 0 to 50% of total virus dose and the effect of varying the priming time from 0 to 4 hours before induction also were investigated. Other factors explored were effects of varying the fetal bovine serum concentration (from 0 to 8%) and individual cow donors on bovine ifn titers. Highest bovine leukocyte ifn titers (15,314 U/ml) were obtained using Sendai virus (priming dose, 60 hemagglutinating units/ml; inducing dose, 240 hemagglutinating units/ml) and incubating for 12 hours. Up to 24 L (over 360 million U) of naturally derived leukocyte ifn were produced at one time.
Granular mucosal lymphocytes in porcine small intestine
Authors: Chu Redman M. , Wang S. H. , Du Y. H.
Published: February 2025

A subpopulation of purified, interepithelial lymphocytes from porcine small intestinal mucosa contained cytoplasmic granules. Toluidine blue staining revealed metachromatic granules in 13.64% (606/4,450) cells. The cells had scant organelles, a single large nucleus with obvious invagination of the nuclear membrane, and prominent chromatin. Each cell contained 1 to 10 cytoplasmic membrane-bound granules, 0.6 to 1.5 μm in diameter. These findings indicated that the granular mucosal lymphocytes are related morphologically to mucosal mast cells. The presence of serotonin in the granules, confirmed by the serotonin releasing test, provided functional evidence that granular mucosal lymphocytes are related to mucosal mast cells.
In vitro effect of T-2 mycotoxin on the immune response of mice
Authors: Holt Peter S. , DeLoach John R.
Published: February 2025

The in vitro biologic effects of T-2 mycotoxin on the immune response of mice was undertaken. Twenty nanograms of toxin abrogated the immune response to the T-dependent antigen sheep rbc, whereas a partial response was observed when 2 ng was used. Analysis of cell culture viabilities indicated that cell death occurred with toxin doses that coincided with the diminished immune responses. A similar decreased response was observed against the T-independent antigen, TNP-lipopolysaccharide, indicating toxic effects on both B and T lymphocyte populations. Delay of toxin administration as much as 116 hours of the 120-hour incubation period still resulted in a substantially diminished immune response, indicating the toxin acts on both the afferent and efferent immune systems. Equal effects were observed for mice of the b, d, and k haplotype, indicating no apparent strain variability in sensitivity to T-2 mycotoxin effects. These results indicated that T-2 mycotoxin can modulate the immune response, and that this modulation is attributable to direct toxic effects on the cells of the immune system.
Susceptibility of dogs to infection with Ehrlichia risticii, causative agent of equine monocytic ehrlichiosis (Potomac horse fever)
Authors: Ristic Miodrag , Dawson Jacqueline , Holland Cynthia J. , Jenny Allen
Published: February 2025

Adult dogs 1 to 5 were inoculated iv and/or sc with 3, 5, or 6 ml of a suspension containing 1.2 × 104 Ehrlichia risticii-infected cells (derived from primary canine monocyte cell cultures)/ml. Dogs 6 to 8 were inoculated iv and/or sc with 3 or 6 ml of 1.2 × 105 organism-free cultured canine monocytes/ml. Ehrlichia risticii was isolated in cultures from inoculated dogs 3, 4, and 5 on postinoculation days (pid) 10 to 16, but not from dogs 6 to 8. Dogs inoculated with E risticii seroconverted between pid 6 and 12. Clinical signs of illness were not observed in these 5 E risticii-inoculated dogs.

A pony, inoculated with E risticii isolated from inoculated dog 5, developed clinical signs of equine monocytic ehrlichiosis, including fever, anorexia, depression, and diarrhea, and E risticii was isolated from the pony's blood. This E risticii isolate was then inoculated into susceptible dog 9, and E risticii was repeatedly isolated from dog 9 during pid 6 to 17. Dogs were susceptible to infection with E risticii and may serve as a reservoir of the organism in the field.
Vertical transmission of channel catfish virus
Authors: Wise Janet A. , Harrell Sandra F. , Busch Robert L. , Boyle John A.
Published: February 2025

Channel catfish broodfish were examined nondestructively for the presence of channel catfish virus (ccv), using a nucleic acid-probing technique. A dot blot assay was tested and shown to be accurate and rapid in the diagnosis of ccv. Two ccv-positive fish were successfully mated, and fertilized eggs were collected. Offspring that hatched were tested and were shown to have ccv. This result indicated vertical transmission of ccv, a herpesvirus.
Immunochemical relationship of three antigens purified from Pasteurella multocida strain P-1059
Authors: Tsuji M. , Matsumoto M.
Published: February 2025

Three antigens were prepared from a type-3 avian strain of Pasteurella multocida, and their chemical and immunologic characteristics were studied. An antigen, designated 2.5S, was extracted with 2.5% NaCl solution and purified by chromatography. Lipopolysaccharide (lps) was extracted with phenol-water, and a third antigen, designated fs, was extracted in 0.3% formalin solution containing 0.85% NaCl and purified by differential centrifugation. The 2.5S and the fs antigens consisted of 40% protein and 15% carbohydrate, whereas lps did not contain a substantial amount of protein. A major protein component with a molecular weight of 44,000 was detected in the 2.5S antigen, as well as in the fs antigen. Of the 3 antigens, lps had the highest activity in mouse lethality and Limulus lysate tests. Antigenic cross-reactions among the 3 antigens were demonstrated by immunodiffusion tests. The 2.5S antigen was indistinguishable from the fs antigen, as both antigens contained the lps component of approximately 45%. Treatments with various reagents indicated that the 2.5S and fs antigens contained at least 2 antigenic determinants. The first was a heat-stable protein sensitive to protease or phenol-water, and the second was a periodate-sensitive carbohydrate, which was a major antigenic determinant on the lps antigen.
Evaluation of relationship among three purified antigens from Pasteurella multocida strain P-1059 and of their protective capacities in turkeys
Authors: Tsuji M. , Matsumoto M.
Published: February 2025

Three antigens were prepared from Pasteurella multocida strain P-1059, and their immunogenicity and antigenic relationships were investigated. The 3 antigens were a soluble antigen purified from a 2.5% NaCl extract (2.5S), a similar antigen purified from an extract in 0.3% formalin solution containing 0.85% NaCl (fs), and lipopolysaccharide (lps). The antigens were treated with various chemicals and enzymes to study their antigenic and immunogenic determinants. Antigenic analyses with elisa inhibition tests indicated that 2.5S and fs were similar lps-protein complex antigens. The 2.5S and fs antigens induced protective immunity in turkeys with high antibody titers against lps antigen. Although lps was a component of 2.5S and fs, lps itself was poorly immunogenic in turkeys. The antigenicity of protein compounds in 2.5S was deteriorated by protease treatment, which, however, did not significantly diminish the protective immunogenicity. Treatment of 2.5S with sodium periodate, altering its carbohydrate moieties, decreased its immunogenicity. The immunogenicity of 2.5S also was abolished by phenol-water treatment, owing to dissociation of the lps-protein complex. These findings suggest that a certain form of lps-protein complex is essential for the induction of immunity against the P multocida infection in turkeys.
Influence of sarcoptic mange and cold and ambient temperature on blastogenic responses of lymphocytes and serum cortisol concentrations of pigs
Authors: Wooten-Saadi E. , Blecha F. , Stevenson J. S. , Broce A. B.
Published: February 2025

Blood samples from sarcoptic mite-infested pigs were evaluated for effects of mite infestation and cold and ambient temperatures on lymphocyte blastogenic responses and for effects of mite infestation on serum cortisol concentrations. In experiment 1, sarcoptic mite-infested and noninfested pigs were housed in cold (5 to 15 C fluctuating) and thermoneural (25 C) environmental chambers for 5 weeks. Differences were not observed (P > 0.10) in blastogenic responses to phytohemagglutin or pokeweed mitogen between lymphocytes from infested and noninfested pigs on postinfestation days (PID) 7, 21, 28, and 35 in either environmental chamber.

When lymphocytes from noninfested pigs were cultured with sera from infested pigs, alterations of blastogenic responses were not detected. Cortisol values were higher (P < 0.05) in sera from sarcoptic mite-infested pigs, compared with those from noninfested pigs, at 4 pm on pid 14 and at 4 am and 10 am on pid 15. Cortisol values were higher (P < 0.05) in sera obtained at 10 am on pid 14 and at 10 am on pid 15 from pigs housed in cold chambers, compared with those from pigs housed in thermoneutral chambers. Interactive effects between sarcoptic mite infestation and cold ambient temperatures were not observed. At 4 am on pid 15 (experiment 2), cortisol values were higher (P < 0.05) in sera of infested pigs, compared with those in noninfested pigs. Seemingly, sarcoptic mange in pigs did not alter mitogen-induced lymphocyte blastogenic responses, but did increase serum cortisol concentrations, indicating that sarcoptic mange may be a stressor in pigs.
Clinical signs and bone changes associated with phosphorus deficiency in beef cattle
Authors: Shupe J. L. , Butcher J. E. , Call J. W. , Olson A. E. , Blake J. T.
Published: February 2025

For 10 years, 42 female Herefords (as they progressed from weanling calves to aged cows) were fed diets individually, with phosphorus (P) content being the only variable. During growth and the first 3 gestations, clinically evident differences were not associated with 2 dietary treatments (approx 12 and 38 g of P/day). During the next 2 gestations (2 years), half the cows from each original treatment group were fed < 6 g of P (n = 21 cows, 11 from the group fed 12 g of P/day and 10 from the group fed 38 g of P/day) daily. The other half were fed diets supplying approximately 8 g of P (n = 11 cows fed 12 g of P/day) and 35 g of P (n = 10 cows fed 38 g of P/day) daily. During the last 3 years of the experiment, all remaining cows were fed diets containing 12 g (n = 19 cows originally fed 12 g) or 19 g (n = 17 cows originally fed 38 g) of P/day.

Cows fed diets containing < 6 g of P/day developed an insidious and subtle complex syndrome characterized by weight loss, rough hair coat, abnormal stance, and lameness. Spontaneous fractures occurred in the vertebrae, pelvis, and ribs. In severely affected cows, fractures did not heal properly. Some bones were demineralized markedly, and the cortical surfaces were porous, chalky white, soft, and fragile. Osteoid tissue was not properly mineralized. Radiography revealed diminished bone density (osteoporosis), cortical thinning, and resorption of trabecular Time-related availability of dietary P initiated excessive turnover of bone, with resultant structural changes and impaired function. Bone structure and general health of the P-deficient cows improved rapidly when they were fed a diet containing > 12 g of P/day.
Single- and multiple-dose pharmacokinetics of intravenously administered vancomycin in dogs
Authors: Zaghlol H. A. , Brown S. Anthony
Published: February 2025

Vancomycin was administered iv to healthy adult female dogs at a dosage of 15 mg/kg of body weight every 12 hours for 10 days. Pharmacokinetic values were determined after the first and last doses. The disposition of vancomycin was not altered by multiple dosing, and little accumulation attributable to multiple dosing was observed. Serum vancomycin concentration after the first and last dose were described, using a 2-compartment open model with first-order elimination. The distribution and elimination half-lives after the single dose were 15.4 ± 2.7 minutes and 137 ± 21.8 minutes (geometric mean ± pseudo-sd), respectively; whereas the distribution and elimination half-lives after the last dose were 11.3 ± 2.61 minutes and 104 ± 11.2 minutes, respectively. The mean (± sd) area-derived volume of distribution was 396 ± 156 ml/kg and 382 ± 160 ml/kg after the first and last dose, respectively. Serum vancomycin clearance was 2.13 ± 0.35 ml/min/kg and 2.49 ± 0.79 ml/min/kg after the first and last dose, respectively, and 25 to 49% of the total dose of vancomycin was recovered in the urine in the first 24 hours after the single dose administered iv. Mean serum vancomycin concentration reached 101.8 ± 30.6 μg/ml and 99.7 ± 28.0 μg/ml at 5 minutes after a single dose and the last of the multiple doses, respectively, and decreased to 0.94 ± 0.58 μg/ml and 1.51 ± 1.44 μg/ml, respectively, at 12 hours after administration. The side effects that accompany vancomycin treatment in human beings were not observed in the dogs; all remained healthy through the end of the experiment. Decreases in serum total protein and albumin concentrations and erythrocyte count were mild. A dosage of 15 mg of vancomycin/kg given every 6 hours to clinically normal dogs would be required to maintain serum vancomycin concentration in the range considered therapeutic in human beings (7 to 80 μg/ml).
Effects of a bovine herpesvirus-1 isolate on reproductive function in heifers: Classification as a type-2 (infectious pustular vulvovaginitis) virus by restriction endonuclease analysis of viral DNA
Authors: Miller J. M. , Van Der Maaten M. J. , Whetstone C. A.
Published: February 2025

A bovine herpesvirus-1 (bhv-1) isolate (fi) from an aborted fetus was used to infect 9 heifers at various stages of gestation. Two heifers were inoculated iv on postbreeding day (pbd) 1, 7, or 14, and 3 heifers were inoculated in the sixth month of pregnancy.

Plasma progesterone assays were used to monitor corpus luteum function in heifers inoculated during early pregnancy. Low progesterone values and infertility were seen in the 2 heifers inoculated on pbd 1. Luteal function remained normal in heifers inoculated on pbd 7 or 14. These 4 heifers inoculated on pbd 7 or 14 carried their fetuses to term, and their calves were free of bhv-1 infection at birth.

Three heifers inoculated during the sixth month of pregnancy also carried their fetuses to term. Two calves were born alive, and bhv-1 was not isolated from nasal swab samples of either calf; the third calf was stillborn. Virus was not isolated from the stillborn calf's tissues, but bhv-1 was isolated from the placenta. Lesions were not detected in several tissues examined by light microscopy, and bhv-1 antigen was not detected by immunohistochemical examination of paraffin sections.

Restriction endonuclease analysis of viral dna was used to compare the fi virus to other bhv-1 isolates (Colorado-1, Iowa, and K22). On the basis of restriction endonuclease analysis, the fi isolate should be classified as a type-2 (infectious pustular vulvovaginitis) virus, specifically subtype a.
Attachment of Mycoplasma bovoculi to bovine conjunctival epithelium and lung fibroblasts
Authors: Salih Barik A. , Rosenbusch Ricardo F.
Published: February 2025

A specialized tip structure in some mycoplasmas facilitates their attachment to host cells. Mycoplasma bovoculi strains FS8-7 and M165/69 did not have specialized membrane structure and did not exhibit capsule when stained with ruthenium red and examined by use of transmission electron microscopy. The organisms attached in vitro to bovine lung fibroblasts, with no apparent specialized structure. Attachment to conjunctival epithelium in vivo was observed (after death) in a calf infected with M bovoculi. Close association between M bovoculi and the host cells was noticed. Mycoplasmal cells pretreated with hyperimmune rabbit serum and labeled with protein A-gold complex had gold particles randomly distributed around the membrane. Gold-labeled monoclonal antibodies, M25.5 and M7.3, which were directed against 2 surface antigens of M bovoculi, also were distributed randomly on the mycoplasmal surface as seen in results of double-labeling experiments.
In vitro Sendai viral replication in pulmonary macrophages from mice treated with 4-ipomeanol
Authors: Durham Stephen K. , Dubovi Edward A. , Castleman William L.
Published: February 2025

The ability of pulmonary macrophages from female mice given 4-ipomeanol (4-ip) to support viral replication in vitro was examined. On posttreatment days 5, 7, and 9, greater numbers of macrophages were recovered in lavage fluid from lungs of mice given 4-ip, compared with those from controls. Pulmonary macrophages recovered in lavage fluid from control mice and from mice given 4-ip supported Sendai virus replication in vitro, and nearly all Sendai virus produced in pulmonary macrophages from both groups was in an infectious form. On posttreatment days 5 and 7, slightly greater absolute numbers of virions were produced in pulmonary macrophages recovered from mice given 4-ip.
Serum and synovial fluid steady-state concentrations of trimethoprim and sulfadiazine in horses with experimentally induced infectious arthritis
Authors: Bertone Alicia L. , Jones Robert L. , McIlwraith C. Wayne
Published: February 2025

The tarsocrural joints of 11 horses were inoculated with 1.2 to 2.16 × 106 viable Staphylococcus aureus organisms susceptible to a trimethoprim-sulfadiazine (tmp-sdz) combination with minimal inhibitory concentration (mic) of 0.25 μg of tmp/ml and 4.75 μg of sdz/ml. Antimicrobial treatment consisted of oral administration of a tmp-sdz combination—30 mg/kg of body weight given once daily (group-1 horses) or 60 mg/kg given as 30 mg/kg every 12 hours (group-2 horses). Paired serum and synovial fluid samples were obtained before intra-articular inoculation with the S aureus, after inoculation with S aureus but before antimicrobial treatment, and after inoculation at various hourly intervals after oral administration of the tmp-sdz combination. The tmp-sdz combination was administered daily in the 2 dosages for 21 days. Samples were collected after day 3 of repetitive drug administration so that drug steady-state concentration would have been achieved. Serum and synovial fluid samples were analyzed for tmp and sdz concentrations.

Administration of the tmp-sdz combination at a dosage of 30 mg/kg once daily was not effective in maintaining tmp or sdz concentrations above the mic of tmp-sdz for the S aureus (0.25 and 4.75 μg/ml for tmp and sdz, respectively) in the infected synovial fluid or in maintaining adequate tmp concentration in the serum. The alternative use of the tmp-sdz combination at a dosage of 60 mg/kg given as 30 mg/kg every 12 hours was effective in maintaining serum and synovial fluid concentrations of tmp and sdz that were greater than the mic for the infective organism. Sulfadiazine concentration was significantly (P ≤ 0.05) lower in the infected synovial fluid sample than that in the corresponding serum sample.

We concluded that administration of 60 mg of tmp-sdz/ kg given as 30 mg/kg every 12 hours is more effective than 30 mg/kg given once daily for the treatment of equine infectious arthritis caused by organisms for which the mic of tmp-sdz is ≤ 0.25-4.75 μg/ml.