bluuebunny/crossref_metadata_2025 huggingface dataset:
Experimental infectious bovine keratoconjunctivitis: Efficacy of a vaccine prepared from nonhemolytic strains of Moraxella bovis
Authors: Pugh G. W. , McDonald T. J. , Kopecky K. E.
Published: February 2025

Calves vaccinated with a bacterin prepared from 4 nonhemolytic strains of Moraxella bovis were challenge exposed with a virulent hemolytic strain of M bovis. Ten calves were given 2 vaccinal inoculations 21 days apart. Twenty-one days after the last vaccinal inoculation, the eyes of the 10 vaccinated and the eyes of the 12 non-vaccinated calves were exposed to a hemolytic heterologous strain of M bovis.

The percentage of eyes with infectious bovine keratoconjunctivitis was lower, the lesions were less severe, and the duration of infection was shorter in vaccinated calves than in nonvaccinated calves. Seemingly, the resistance induced by nonhemolytic strains of M bovis was at least comparable with the induced by hemolytic virulent strains of that organism. The nature of the immune response in vaccinated calves is discussed.
Quantitation of hyaluronic acid in equine synovia
Authors: Rowley G. , Antonas K. N. , Hilbert B. J.
Published: February 2025

An assay for the determination of hyaluronic acid concentration in equine synovia (synovial fluid) was investigated. The method involved the degradation of hyaluronic acid, using a highly specific microbial enzyme. The unsaturated tetra- and hexasaccharide products were oxidized with periodate and caused to react with thiobarbituric acid to form a chromophore which absorbed in the visible range of the spectrum. The method was precise within acceptable limits for synovia and compared favorably with the widely used carbazole method of Bitter and Muir (Anal Biochem 4:330-334, 1962). The between-assay coefficient of variation was 1.7% and the method was found to be linear to 100 μg of hyaluronic acid. The mean value for hyaluronic acid concentration in synovia of healthy horses was 127 mg/100 ml.
Effect of time of sample collection, milk composition, and stage of lactation on the growth-promoting properties of milk for Streptococcus agalactiae
Authors: Brown R. W. , McDonald T. J.
Published: February 2025

Milk samples were taken from noninfected mammary quarters before the am milking and at intervals after milking. The pH values of the post-am milk samples were higher than the am foremilk samples for approximately 3 to 6 hours after milking. When these samples were pasteurized, inoculated with a culture of Streptococcus agalactiae, and incubated at 37 C for 24 hours, there was a greater pH change (ΔpH) in the post-am milks. The higher pH and ΔpH values of 3-hour samples coincided with higher concentrations of bicarbonate and chloride, lower concentrations of citrate and phosphate, and lower titratable acidities.

Milk samples were taken before the am milking and 3 to 4 hours later from 2 noninfected quarters of each of 2 cows at weekly intervals for 9 months. The growth of S agalactiae in the milk samples showed that the ΔpH and bacterial counts (i) increased as the lactation progressed and milk yield decreased, (ii) were higher in the 3- to 4-hour samples than in the am samples, and (iii) were higher in the whole milk than in the skim milk of the 3- to 4-hour samples; this difference was attributed to the cream layer and in most instances could be duplicated by layering liquid petrolatum on the surface of skim milk. Also, the bacterial counts in the 3- to 4-hour skim milks were higher than those of the corresponding am skim milks in 78% of the paired samples, which indicated that another factor, in addition to the cream layer, might be involved in promoting better in vitro growth of S agalactiae in the 3- to 4-hour milk.
Immunocytochemical labeling of Anaplasma marginale Theiler in Dermacentor andersoni Stiles with peroxidase-antiperoxidase technique
Authors: Staats Jacque J. , Kocan Katherine M. , Hair Jakie A. , Ewing S. A.
Published: February 2025

Colonies of Anaplasma marginale in midgut epithelial cells of adult ticks that had been infected as nymphs were specifically labeled, using the unlabeled antibody peroxidase-antiperoxidase method of immunocytochemistry. Visual comparison of infected and control tissue sections with the electron microscope demonstrated deposition of ringlike peroxidase-antiperoxidase complexes over organisms within the colonies. The intensity of labeling differed among organisms within a single colony, possibly as a result of varying antigenicity. The labeling observed on organisms in the colonies was similar to that seen on anaplasmal initial bodies in inclusions of infected bovine erythrocytes examined concurrently.
Migration of polymorphonuclear leukocytes into the bovine mammary gland during experimentally induced Staphylococcus aureus mastitis
Authors: Hannon R. J. , Heald C. W.
Published: February 2025

The process of neutrophilic polymorphonuclear leukocyte (pmn) migration in the bovine mammary gland during experimental Staphylococcus aureus challenge was studied, using light and electron microscopies. The pmn were observed in various stages of margination in capillary lumens and migration into perivascular spaces. In infected tissue showing little evidence of epithelial damage, numerous pmn were accumulated in the perivascular space and aligned against the epithelial basal lamina, but not in the alveolar lumen. Other areas of infected tissue showed progressive tissue degeneration (autophagic vacuoles, vesiculation of endoplasmic reticulum, and cellular debris in the luminal milk) with the appearance of numerous pmn in lumens. The pmn were observed between the basal end of adjacent epithelial cells having intact tight junctions, but were never seen traversing the junctional complex. Some pmn lying between intact epithelial cells appeared to have ingested fat globules before entering the lumen. Although the mechanism by which pmn crossed tight junctions was not explained, alveoli with a portion of the epithelium sloughed off were frequently seen. The pmn appeared to be entering alveoli in large numbers at these damaged sites. There was also marked pmn infiltration in tissue from teat and gland cisterns of S aureus-infected quarters.
Thromboxane, prostaglandin I2(epoprostenol), and the hemodynamic changes in equine endotoxin shock
Authors: Bottoms G. D. , Templeton C. B. , Fessler J. F. , Johnson M. A. , Roesel O. F. , Ewert K. M. , Adams S. B.
Published: February 2025

This study had 2 objectives: (i) to correlate plasma thromboxane and prostaglandin I2 (epoprostenol) concentrations with hemodynamic changes occurring in equine endotoxin shock, and (ii) to determine the effects of flunixin meglumine on plasma concentrations of these prostaglandins relative to hemodynamic changes. Shock was induced in 2 groups, each of 4 anesthetized ponies, and in a 3rd group of 2 ponies. Group A ponies were given endotoxin only (and were not treated), and group B ponies were given endotoxin and then treated with flunixin meglumine. Group C ponies were treated with flunixin meglumine 5 minutes before they were given endotoxin. Arterial, pulmonary arterial, and central venous pressures were measured and blood samples were collected at 0, 0.1, 0.25, 0.5,1, 2, 3, and 4 hours after ponies were given the endotoxin.

The plasma thromboxane and prostaglandin I2 concentrations were increased in equine endotoxic shock. Increased thromboxane concentration was associated with the high pulmonary arterial and central venous pressures and low arterial blood pressure in the minutes immediately after the ponies were given endotoxin. The increased prostaglandin I2 concentration was associated with systemic hypotension at 1 to 2 hours after endotoxin. Treatment of ponies with flunixin meglumine after endotoxin was given (group B) prevented the prostaglandin I2 rise and the associated hypotension. Treatment with flunixin meglumine before endotoxin was given prevented the increase of the plasma thromboxane and prostaglandin I2 values, along with the associated hemodynamic changes.
Variable-interval responding in the horse: A sensitive method of quantitating effects of centrally acting drugs
Authors: Shults Theodore , Combie Joan , Dougherty John , Tobin Thomas
Published: February 2025

An operant conditioning apparatus for studies in equine pharmacology was constructed. Horses interacted with this apparatus by breaking a light beam and were rewarded with 30 ml of oats. Horses readily learned to use this apparatus and were trained to respond on a variable-interval-60 schedule. With this schedule, there was no direct relationship between the rate of light beam breaking and the reward. Horses thus developed their own individual response rates (ie, light-beam breaking rates), and these rates remained stable at between 5 and 35 responses/min for each horse over a period of months.

The effects of 2 drugs on this paradigm were tested. Reserpine (5 mg/horse, iv) depressed the response rate in all horses tested. This depression was maximal between 3 and 5 days after treatment and lasted for up to 10 days. After small doses of cocaine (0.01 mg/kg of body weight iv), the response rate of 1 horse was stimulated, whereas 1 mg of cocaine/kg was required for maximal stimulation of response rate in another horse. Larger doses of cocaine inhibited response. Variable-interval response was a sensitive method of measuring drug effects in the horse and allowed accurate quantitation of drug effects that were not detectable by clinical observation.
Comparative efficacy of five supplementation procedures to control selenium-vitamin E deficiency in swine
Authors: Van Vleet John F.
Published: February 2025

Thirty-five weanling pigs were fed a basal torula yeast diet (bd) severely deficient in selenium and vitamin E (Se-E) for up to 8 weeks to determine the efficacy of 5 Se-E supplementation procedures. Complete protection against deaths from Se-E deficiency and development of lesions of Se-E deficiency in survivors was afforded by feeding supplements of Se (0.2 mg/kg of feed, as selenite) and/or vitamin E (33 IU/kg of feed, as α-tocopheryl acetate). An initial im injection of Se-E (0.25 mg of Se/kg of body weight and 17 IU of α-tocopheryl acetate/kg of body weight) prevented deaths from Se-E deficiency, but lesions of Se-E deficiency were present in survivors. The initial im injection of vitamin E (17 IU of α-tocopherol/kg of body weight) did not prevent deaths or lesions of Se-E deficiency, but slightly increased survival time beyond that for pigs fed bd only.

Addition of Ag (3,000 mg/kg of BD) accentuated Se-E deficiency with markedly decreased survival time, but supplements of Cu (500 mg/kg of bd) did not.

Lesions of Se-E deficiency in the 35 pigs fed bd, with or without supplements, were acute or chronic hepatosis dietetica (macroscopically and microscopically in 18 pigs), myocardial necrosis (macroscopically in 3 pigs and microscopically in 20 pigs), and necrosis in skeletal muscle (macroscopically in 1 pig and microscopically in 10 pigs). Esophagogastric ulceration occurred in 34 of 35 pigs fed bd with or without supplements.

Determination of serial serum and terminal hepatic Se content indicated rapid and marked changes directly related to Se intake, except in pigs fed bd + Ag which showed markedly increased terminal hepatic Se content. Erythrocytic glutathione peroxidase (gsh-Px) activity also varied directly with Se intake, but was altered less than were serum and hepatic Se content. Concentration of plasma and hepatic α-tocopherol varied directly with intake of vitamin E. Serum aspartate aminotransferase activity was markedly increased only in pigs that had severe lesions of Se-E deficiency and were within several days of death.

Deaths and lesions of Se-E deficiency did not develop in pigs until (i) serum Se content was < 0.025 μg/ml, (ii) hepatic Se content was < 0.10 mg/kg of tissue (except in pigs fed Ag), (iii) plasma α-tocopherol content was < 0.40 μg/ml, and (iv) hepatic α-tocopherol content was < 0.75 μg/g of tissue. Erythrocytic glutathione peroxidase activity decreased too slowly to predict the onset of deaths and lesions of Se-E deficiency in the pigs of the present rapid depletion study.
Extraosseous vascular supply to the mature dog’s coxofemoral joint
Authors: Kaderly Robert E. , Anderson Wesley D. , Anderson Bettina G.
Published: February 2025

Blood vessels supplying the coxofemoral joint were identified and described in 8 healthy, mature dogs. An accurate representation of the blood vessels was obtained by intraarterial methyl methacrylate injection and sodium hydroxide corrosion of soft tissues until only the pelvis, femurs, and casts of the blood vessels remained. The sources of vascular supply to the dog’s coxofemoral joint, from most to least contributory, were the lateral circumflex femoral artery, the medial circumflex femoral artery, the caudal gluteal artery, the cranial gluteal artery, and the iliolumbar artery.

In addition, important vascular relationships were demonstrated. Many blood vessels were associated with the periosteal surfaces of the coxofemoral joint in areas of muscular and articular capsular attachment; fewer vessels were present in areas of loose periosteal attachment. Also, extra-articular anastomoses were identified. The most significant anastomosis was an extracapsular vascular ring located at the femoral attachment of the articular capsule. The extracapsular vascular ring was formed by branches of the lateral and medial circumflex femoral and caudal gluteal arteries.
Acute toxicosis of budgerigars (Melopsittacus undulatus) caused by pyrolysis products from heated polytetrafluoroethylene: Clinical study
Authors: Wells R. E. , Slocombe R. F. , Trapp A. L.
Published: February 2025

Polytetrafluoroethylene (ptfe), a synthetic polymer widely used as a nonstick surface in cookware, releases toxic pyrolysis products when exposed to excessive heat. Thirty-two budgerigars (Melopsittacus undulatus) were exposed to pyrolysis products of either heated ptfe cookware or plain aluminum cookware in a specially designed exposure chamber for given periods. Clinical signs were recorded and necropsies were done on all birds at the termination of each exposure period. The ptfe products caused acute respiratory distress and rapid death in many of the exposed birds. At necropsy, lesions were seen only in the respiratory tract—extensive pulmonary hemorrhage and congestion.
Pneumatically powered vertebral displacement device for dogs
Authors: Fialho Sergio A. G. , Lumb William V. , Scott Robert J.
Published: February 2025

A pneumatically powered trauma device was developed to produce vertebral displacement and spinal cord injury in dogs. After surgical exposure of the spine, displacement was done without laminectomy or cutting of the intervertebral disc.

Trauma resulted in luxation between L1 and L2 or fractures of L1 and L2. Force required to cause displacement was recorded via a load sensing system and ranged between 1,848 and 2,666 newtons. In a few dogs, there was partial return of the displaced segment upon pressure release from the device at posttrauma hour 4. The device was an effective means of producing spinal injuries in dogs, and provides a method for studying spinal column and spinal cord injuries.
Canine bladder epithelial cells in culture: Susceptibility to canine distemper and measles viruses
Authors: Bui Hong Dang , Tobler Leslie H. , Van Pelt Lloyd F. , Howard Edwin B. , Imagawa David T.
Published: February 2025

A canine bladder epithelial cell strain was established in culture for the study of canine distemper virus. Epithelial cells were scraped off the bladder with a scalpel and were cultured in enriched Eagle’s medium. Cells were enzymatically dispersed and passed over 46 population doublings which covered a period of more than 3 years. The cells were heteroploid when karyotyped at passage level 5 and 42. This cell strain permitted direct isolation of canine distemper virus and also showed susceptibility to laboratory strains of measles virus. Seemingly, establishment of cell strains from canine bladder epithelium can be accomplished without difficulty.
Noninvasive measurement of systemic arterial pressure in dogs by automatic sphygmomanometry
Authors: Hamlin R. L. , Kittleson M. D. , Rice D. , Knowlen G. , Seyffert R.
Published: February 2025

Mean, systolic, and diastolic systemic arterial blood pressures were recorded by indirect automatically inflating and deflating sphygmomanometry, using an oscillometric principle in 9 anesthetized dogs whose blood pressures were varied by infusions of sodium nitroprusside and phenylephrine. Blood pressures fluctuated between a diastolic pressure of 40 mm of Hg and a systolic pressure of 210 mm of Hg. A total of 147 blood pressures, measured by indirect sphygmomanometry, were compared with those obtained from a cardiac catheter within the artery of the contralateral limb. The device also indicated heart rate. Correlation coefficients between actual pressures from the cardiac catheter and those registered by the oscillometric device were > 0.9 for all pressures, and correlation coefficient for heart rate was 0.827. The lower correlation for heart rate was a consequence of (i) the slow sinus arrhythmia produced in response to phenylephrine and (ii) the device recognizing catacrotic waves as primary pulsations. In the anesthetized dog, this device is reliable, simple to use, and may be of value for monitoring dogs during surgery. Preliminary subjective evaluation indicated that the device is useful for measuring systemic arterial pressures in unanesthetized dogs as well, as long as motion of the limb around which the cuff is placed is minimal.
Enterotoxin production and resistance to antimicrobial agents in porcine and bovine Escherichia coli strains
Authors: de Lopez Aura G. , Kadis Solomon , Shotts Emmett B.
Published: February 2025

A select group of porcine and bovine Escherichia coli strains capable of causing diarrheal disease in neonatal pigs and calves, respectively, were tested for enterotoxin production and resistance to 23 different antimicrobial agents. Thirty-four of the 39 porcine strains tested were enterotoxigenic; that is, they synthesized heat-stable (st), together with heat-labile (lt), enterotoxin; st toxin alone, or lt toxin alone. Fourteen of the 15 bovine strains tested produced st toxin only, whereas 1 strain elaborated lt toxin only. All of the strains were multiple-drug resistant. Among the porcine strains, 2 were resistant to 6 of the antimicrobial agents, and 1 was resistant to 18 of the drugs. All of these strains were resistant to cloxacillin, lincomycin, and penicillin G. None of them was resistant to chloramphenicol, colistin, gentamicin, polymyxin B, or nalidixic acid. One of the bovine strains was resistant to 7 of the drugs, and 1 strain was resistant to 17 of these antimicrobial agents. All of the bovine strains exhibited resistance to cloxacillin, lincomycin, novobiocin, pencillin G, sulfathiazole, sulfamethizole, and triple sulfa (sulfadiazine, sulfamerazine, and sulfamethazine). None of these strains showed resistance to gentamicin, nalidixic acid, nitrofurazone, or nitrofurantoin.
Host defense systems in cattle exposed to polybrominated biphenyl
Authors: Kateley John R. , Insalaco Robin , Codere Susan , Willett L. B. , Schanbacher F. L.
Published: February 2025

In vivo and in vitro immunologic studies were undertaken in 114 Holstein cattle, 60 of which had detectable polybrominated biphenyls (pbb) in adipose tissue. The tissue pbb concentrations were between 0.02 and at least 1,000 mg/kg. An immunologic test profile was used to evaluate the influence of pbb on bovine immune competence. The profile included serum immunoglobulin determinations, autoantibody studies, lymphocyte subpopulation determinations, lymphoblastogenesis assays, delayed hypersensitivity skin testing, and neutrophil function studies.

The results of the evaluation indicated that the host defenses are intact, both in quantity and function, in cattle with pbb body burdens ranging from 0.02 to 24.0 mg/kg for at least 2 years. Cattle fed 25 g of pbb daily during the acute toxicity study exhibited usual immune competence until they accumulated 500 g of pbb (tissue concentrations exceeding 1,000 mg/kg). Cattle that were fed more than 500 g of pbb became moribund and exhibited changes in neutrophil function tests and serum antibody titers.
Effect of levamisole in immune responses to bovine herpesvirus-1
Authors: Babiuk L. A. , Misra V.
Published: February 2025

The effect of levamisole on bovine immune responses to infectious bovine rhinotracheitis virus was assessed under laboratory and commercial feedlot situations. In all instances, levamisole appeared to have a beneficial effect on antibody responses of the cattle after vaccination. In the smaller scale pilot trials, levamisole appeared to be more efficacious when given 7 days after vaccination, presumably when a large amount of viral antigen was present as a result of viral replication. In the larger feedlot trial, however, response to administration of levamisole at the time of vaccination appeared to be slightly better than if given 7 days later. In all instances that animals had an antibody response before they were challenge-exposed with virulent virus, rectal temperature responses remained below 40 C, indicating that a threshold level of immunity may be acquired after the vaccination and that elevation of this threshold level does not necessarily alter the clinical disease. However, the amount of virus replication and shedding after challenge exposure seemed to be correlated with the level of immunity. These results are discussed in relationship to the role of immunity levels to spread of virus within a feedlot.
Bovine anaplasmosis: Clinical, hematologic, and serologic manifestations in cows given a long-acting oxytetracycline formulation in the prepatent period
Authors: Lincoln S. D. , Eckblad W. P. , Magonigle R. A.
Published: February 2025

The prophylactic efficacy of a long-acting oxytetracycline formulation was determined in 36 susceptible cows experimentally inoculated with Anaplasma marginale. Each of 10 cows in 3 treatment groups (T2, T3, T4) were given im injections of 20 mg of oxytetracycline/kg of body weight once, twice, or three times during the prepatent period. The T2 group was treated once at 1 week after experimental inoculation, the T3 group was treated 2 times (at 1 and 2 weeks) after exposure, and the T4 group was treated 3 times (at 1, 2, and 3 weeks) after exposure. Six cows comprising group T1 served as nonmedicated controls.

Treatment of cattle in the prepatent period with the long-acting oxytetracycline formulation produced significantly fewer clinical anaplasmosis cases. This reduction in frequency was proportional to the number of weekly treatments given. In cattle which developed clinical disease, only 1 im injection of 20 mg of oxytetracycline/kg was necessary to induce recovery. The prepatent period in the treated cattle was extended approximately 30 days beyond the prepatent period of the control cattle after their final treatment. Humoral rapid card agglutinating and complement fixing antibodies regularly were present in the cows 10 days after they were inoculated; however, neither the presence of antibody nor that of the antibiotic was sufficient to prevent establishment of the carrier state in the principals.
Rocky Mountain spotted fever in areas of high and low prevalence: Survey for canine antibodies to spotted fever rickettsiae
Authors: Kelly D. J. , Osterman J. V. , Stephenson E. H.
Published: February 2025

Antibodies to Rickettsia rickettsii were detected by indirect immunofluorescence in sera from 149 of 467 dogs (32%) examined from 4 military installations located in Kentucky, North Carolina, Pennsylvania, and Virginia. The prevalence at individual installations ranged from 4.3% at Fort Knox, Ky, to 63.4% at Fort Bragg, NC. Most of the seropositive dogs were in the working and sporting groups of dogs. The difference in antibody prevalence between sexes was not significant. Serologic responses were related to R rickettsii infection, although antibodies to R montana also were detected in a few of the sera. Comparison of serodiagnostic methods indicated that the indirect fluorescent antibody test was more sensitive than was the indirect hemagglutination test for obtaining survey data on the prevalence of Rocky Mountain spotted fever in an area.
Coagulation, fibrinolysis, and kinin generation in adult cats
Authors: O'Rourke Laurie , Feldman Bernard F. , Ito Ralph K.
Published: February 2025

Screening coagulation tests, coagulation factors, and components of fibrinolysis and kinin generation were examined in 21 healthy adult cats. Observed ranges for screening tests were: prothrombin time, 7.3 to 11.4 s; activated partial thromboplastin time, 10.6 to 14.9 s; and thrombin time, 10.7 to 18.9 s. Functional coagulation factors II, V, VII, VIII, IX, X, XI, and XII were assayed and expressed as percentage of normal. Although individual factors varied, the observed range for factors assayed was 37% to 208% of normal. Fibrinogen ranged from 50 to 165 mg/dl. Plasminogen and antithrombin III ranged from 50% to 200% and 89% to 111% of normal, respectively. Plasma kallikrein ranged from 0.3 to 3.9 μkat/L. Fibrin(ogen) degradation products and fibrin monomers were examined with variable and inconsistent results.
Ultrastructure of the pineal gland of the mink (Mustela vison)
Authors: Rouvet D. M.
Published: February 2025

The pineal gland of the mink (Mustela vison) was examined, using light and electron microscopy. Its cellular structure was compared with that of the pineal gland in other mammalian species, including that of a close taxonomic relative, the ferret.

The pineal gland of the mink was composed of pinealocytes and neuroglial cells, as well as numerous neuron cell processes and nerve endings, which provide extensive neural input to the pineal gland. A high degree of vascularity, extent of neural innervation, pinealocyte organelles, and presence of extensive pinealocyte processes with secretory granules indicate an active secretory function. This secretory function is postulated to be associated with the onset of the yearly reproductive cycle in the mink.
Naturally occurring porcine proliferative enteritis: Pathologic and bacteriologic findings
Authors: Lomax Larry G. , Glock Robert D.
Published: February 2025

The lesions of porcine proliferative enteritis were studied by light and electron microscopic techniques in feeder pigs, fattening hogs, bred gilts, sows, and boars.

The characteristic microscopic feature common to all age groups was proliferation of immature crypt epithelial cells, primarily in the ileum and the distal part of the jejunum. Similar changes were also observed in the midjejunum, cecum, and colon of a few swine.

The earliest detectable microscopic lesion was focal proliferation of crypt epithelial cells with accompanying inflammation of the lamina propria and leukocytic exudate within affected crypt lumina. Lesions progressed to diffuse crypt cell proliferation, elongation of crypts, and loss of villi.

Immature epithelial cells contained variable numbers of intracytoplasmic, nonmembrane-bound, curved organisms resembling Campylobacter sp bacteria. Similar organisms were within phagolysosomes of macrophages in the lamina propria and within the cytoplasm of crypt epithelial cells undergoing mitosis.

Campylobacter sputorum subsp mucosalis was isolated from the ileal mucosa in 30 of 58 swine.
Piretanide (HOE 118) in dogs
Authors: Lumb W. V. , Seegmiller J. , Scott R. J.
Published: February 2025

Piretanide, a “loop” diuretic, was administered orally and iv at 3 dose levels to healthy Beagles. The effects were measured over an 8-hour period. A marked diuresis occurred with both methods of administration at all dose levels. It was characterized by increased excretion of Na+, Cl-, and, to a lesser extent, K+. Urine osmolality and specific gravity decreased significantly, while urine Na+ and K+ concentrations decreased concurrently. Changes from base lines were not detected in hematologic values, except for serum K+ which reached below base line with larger doses.

Piretanide is a potent diuretic and treated patients should be monitored for hypokalemia.
Effect of aspirin on collateral blood flow after experimental thrombosis of the feline aorta
Authors: Schaub Robert G. , Gates Kathy A. , Roberts Royce E.
Published: February 2025

In 11 cats, the caudal aorta was occluded with a thrombus to inhibit opening of collateral vessels to the hindlimbs. Five cats were not treated, and 6 cats were given aspirin (650 mg, orally) 1 hour before aortic occlusion. Before the aortas were occluded, platelet counts were measured in the 11 cats, and platelet aggregation by adenosine diphosphate was assessed in 4 cats scheduled for aspirin treatment. Cats were maintained for 3 hours after surgery, and the tests were repeated. In addition, serum salicylate concentrations were determined for all aspirin-treated cats. Collateral circulation was assessed as the time necessary for contrast media to appear in the iliac arteries caudal to the thrombus during aortography.

Platelet counts were significantly (P ≤ 0.05) reduced in nontreated cats, but not in the aspirin-treated cats. Serum salicylate concentrations indicated that aspirin had reached therapeutic blood concentrations. Inhibition of adenosine diphosphate-induced platelet aggregation was observed in all postthrombosis aspirin-treated cats. Contrast media did not appear in the iliac arteries of nontreated cats until 7.5 ± 0.5 s after injection. In all aspirin-treated cats, contrast media appeared in the iliac arteries within 2.3 ± 0.3 s after injection. Platelet thromboxane A2 may be the factor promoting collateral inhibition after aortic thrombosis in cats.
Controlled tests of pastes of dichlorvos and thiabendazole against induced Strongyloides westeri infections in pony foals in 1973-1974
Authors: Drudge J. H. , Lyons E. T. , Tolliver S. C.
Published: February 2025

In 1973-1974, 4 controlled tests were performed in pony foals (n = 17) raised parasite-free and experimentally infected with Strongyloides westeri. Administration of infective larvae by stomach tube in 1 test resulted in low-grade infections and tended to invalidate the test. Intraoral and percutaneous (intra-aural) administration of larvae resulted in suitable test infections for 1 and 2 tests, respectively. A paste formulation of dichlorvos at 36.3 mg/kg of body weight resulted in variable (71% to 100%) removal from 4 ponies. Treatment of 4 ponies with pastes of thiabendazole at the dosage rate of 44 mg/kg was consistently effective (> 99% to 100%) for eliminating intestinal infections of S westeri.
Activity of ivermectin against canine intestinal helminths
Authors: Anderson Dennis L. , Roberson Edward L.
Published: February 2025

The anthelmintic activity of ivermectin was tested in 98 dogs against adult ascarids (Toxocara canis, Toxiscaris leonina), hookworms (Ancylostoma caninum, A braziliense), and whipworms (Trichuris vulpis), and against experimentally induced infections (4th-stage larvae) of T canis and 4 caninum. Dosage levels tested were single subcutaneous injections of 50, 100, 200, or 400 μg/kg of body weight with appropriate vehicle-treated controls. A minimum of 4 (usually 5) dogs were tested with each parasite and dosage level. The lowest dosage level, 50 μg/kg, and all higher dosage levels expelled > 99% of the adult forms of both species of hookworms and intesinal larval forms of A caninum, as determined by worm counts at netropsy. A dosage level of 100 μg/kg was required to expel > 99% of whipworms and 200 μg/kg was necessary o expel adult (91%) and larval (97%) stages of T canis. Ivermectin was only marginally effective (34.2%, 46.2%, 69.2% and 53.8%) against Toxascaris leonina at 50, 100, 200, and 400 μg/kg, respectively, and had no effect against occasional infections with the tapeworms, Dipylidium caninum (14 logs) and Taenia spp (3 dogs).
Blood volume of nonsplenectomized and splenectomized cats before and after acute hemorrhage
Authors: Breznock E. M. , Strack D.
Published: February 2025

Blood volume (bv) was determined in awake, nonsplenectomized (nspx) and splenectomized (spx) cats before and after hemorrhage (6 ml/kg). Each nspx cat had a determined bv at least 10 ml/kg greater than the same cat after splenectomy. The mean bv of spx cats was 43.4 ± 8.94. ml kg (4.3% of body weight). The calculated rbc masses of nspx and spx cats were 17.0 ± 4.07 and 12.2 ± 1.12 ml/kg, respectively. Each nspx cat had apparent rbc masses of 5 ml/kg greater than that of the same cat after splenectomy was done. At 1 hour after a hemorrhage, the bv and rbc masses determined in spx cats were 46.7 ± 12.1 and 9.7 ± 1.90 ml/kg, respectively. Extravascular-to-intravascular fluid flux (calculated from rbc masses and plasma protein dilution) was approximately 0.80% of body weight. The indirect method with 51Cr-labeled rbc for bv determination was accurate and precise in awake, spx cats; in awake, nspx cats, the 51Cr-labeled rbc dilution method was precise, but not accurate. The spleen in the cat resulted in marked overestimations of bv and rbc masses.
Isolation of an in vitro-produced soluble Anaplasma-albumin complex
Authors: James Mark A. , Montenegro-James Sonia , Ristic Miodrag
Published: February 2025

A soluble Anaplaszna-albumin complex was isolated from supernatants of A marginale cultures by affinity chromatography. Holstein calves inoculated with this fraction introduced anti-A marginale antibodies detected in the indirect fluorescent antibody test at titers similar to those found in cattle immunized with unfractionated culture supernatant. Titers of both groups peaked slightly above 1:2,000 on postinoculation day 46.
Bovine peripheral blood polymorphonuclear neutrophil chemotactic response to Pasteurella haemolytica or zymosan-activated serum
Authors: Bruecker K. A. , Schwartz L. W.
Published: February 2025

The chemotactic influence of Pasteurella haemolytica and of products of its growth was evaluated in vitro, using bovine peripheral blood polymorphonuclear neutrophils (pmn) in an underagarose migration assay system. Pasteurella haemolytica was cultured, quantitated, killed, and lysed by freeze-thawing. The pmn directional migration toward P haemolytica lysate was not significantly (P > 0.9) different from spontaneous random pmn migration. Also, there was no chemotactic effect of viable 6-hour cultures of P haemolytica when tested in the in vitro underagarose system. Directional migration (1.70 ± 0.53 nun) of pmn to zymosan-activated pooled bovine serum was observed and determined to be significantly (P < 0.001) greater than was spontaneous random pmn migration (0.84 ± 1.21 mm).
Electrocardiographic changes in induced hyperkalemia in ponies
Authors: Glazier D. B. , Littledike E. T. , Evans R. D.
Published: February 2025

In 11 crossbred ponies, hyperkalemia was induced by acute intracardiac infusion of a 0.4M solution of potassium chloride. The ecg changes noticed can be assigned to 4 stages: (1) a widening and a lowering of amplitude followed by inversion and final disappearance of the P wave; (2) an increase in the amplitude of the T wave; (3) an increase in the QRS interval, with some irregularity in the ventricular rate; and (4) periods of cardiac arrest that became terminal or were followed by ventricular fibrillation.

At plasma potassium values of > 7.5 mM/L, the T-wave amplitude and duration of QRS increased. In most ponies, a 50% increase in the QRS duration was present when K+ values were 9 to 10 mM/L. The P waves are absent at plasma K+ values of 9.4 to 12.6 mM/L. Sinusoidal-shaped QRS-T complexes and periods of cardiac arrest occurred before the development of the terminal dysrhythmia. At plasma K+ values of 11.3 to 17.3 mM/L, cardiac standstill or ventricular fibrillation occurred.

The Q-0 Tc and Q-Tc intervals were not altered by hyperkalemia.
Case study of a diabetic dog with chronic membranous glomerulopathy treated with continuous intraperitoneal insulin infusion
Authors: Janle-Swain Elsa , Thornhill Jerry A. , Carter James M. , Hinsman Edward , Jackson Horace D. , Ash Stephen R.
Published: February 2025

The purpose of this study was to determine the use of continuous, intraperitoneal insulin infusion over an extended period (in maintaining metabolic control) and to evaluate the benefits of this treatment in reversing the kidney pathology of a chronic diabetic dog with membranous glomerulopathy.

Hyperglycemia was eliminated, but reevaluations of the insulin infusion pattern were necessary. An initial kidney biopsy revealed fusion of the foot processes, thickening of the basement membrane, and subendothelial deposition. After 5 months of infusion, there was less fusion of the foot processes and a decrease in the subendothelial deposition. Urinary protein loss decreased from 17.3 g/day to 625 mg/day after 2 months of infusion. The dog gained weight, muscle wasting was reversed, and his stamina returned while on continuous insulin infusion.

The reduction of a life-threatening urinary protein loss to a tolerable level and the improvement in the microscopic kidney lesions observed indicate that this treatment with insulin infusion may be beneficial in the management of long-term diabetic dogs, affected with advanced kidney lesions secondary to diabetes.
Immunologic changes in acute canine blastomycosis
Authors: Legendre Alfred M. , Becker Penny U.
Published: February 2025

Immunologic evaluations were done on a total of 21 dogs presented with acute blastomycosis. There were significant increases in serum α2-, β-, and γ-globulins with decreases in albumin concentration. Serum immunoglobulin G was significantly increased, while immunoglobulin M was decreased.

Lymphocyte reactivity was evaluated in 6 dogs with acute blastomycosis. There were significant reductions in lymphocyte reactivity in autologous sera to pokeweed, concanavalin, and phytohemagglutinin stimulation. In addition to decreased reactivity of lymphocytes in dogs with normal lymphocyte counts, 40% of dogs with acute blastomycosis were lymphopenic. Abnormalities in cellmediated immunity may have a role in the pathogenesis of canine blastomycosis.
Caprine arthritis-encephalitis: Clinicopathologic study
Authors: Woodard J. Carroll , Gaskin J. M. , Poulos P. W. , MacKay R. J. , Burridge M. J.
Published: February 2025

Chronic arthritis caused by caprine arthritis-encephalitis virus was observed after the introduction of new animals into a goat herd. There were high frequency of carpal hygroma and clinical signs of stiffness. The disease was progressive and produced a debilitating lameness among 30% of the affected animals. Laboratory findings were limited to alterations in synovial fluid which showed increased numbers of lymphocytes. Pathologic changes were observed in the joints, bursae, and adjacent tissues. Vascular injury and capillary leakage resulted in exudation into synovial cavities. Fibrin coated the synovial lining and formed (amorphous) long thread-like or broad-based villi. The articular cartilage was eroded. Cartilage erosion and penetration of the articular cartilage by pannus were associated with the presence of subchondral pseudocysts. The morphologic changes in bone and synovial tissues were like those described in human rheumatoid arthritis, except that rheumatoid nodules were not observed.
Experimentally induced parainfluenza type 3 virus infection in young lambs: Pathologic response
Authors: Cutlip R. C. , Lehmkuhl H. D.
Published: February 2025

Pulmonary changes in five 1-week-old, colostrum-deprived lambs transtracheally inoculated with parainfluenza type 3 virus were studied by immunofluorescent, microscopic, and ultrastructural techniques. The lambs were killed at postinoculation days (pid) 3, 5, and 7. Immunofluorescence specific for parainfluenza type 3 virus was first seen in small airways and alveolar epithelium and later in the lumens of airways and alveoli and, to a lesser extent, in the interstitium of the lungs. Grossly, there were multifocal areas of consolidation in all lobes of the lungs. These areas were characterized microscopically by bronchiolitis and interstitial pneumonitis. The bronchiolitis involved the terminal airways and consisted of necrosis and sloughing of epithelial cells followed by hyperplasia of the epithelium. The interstitial lesion comprised extensive infiltration of alveolar septa and alveoli with macrophages and the necrosis of alveolar epithelium. This was followed by hyperplasia of the epithelium. Degenerated bronchiolar and alveolar epithelium contained numerous intracytoplasmic inclusions early in the infection, but such inclusions were not seen in the lambs killed at pid 7. The degenerated changes were also seen with the electron microscope, as were numerous inclusions of viral nucleoprotein and a few viral buds at pid 3 and 5. Viral inclusions and buds were seen in ciliated and nonciliated bronchial epithelial cells and type I and type II alveolar epithelial cells.
Effect of thyroid hormone supplementation on chronic doxorubicin (adriamycin)-induced cardiotoxicity and serum concentrations of T3 and T4 in dogs
Authors: Van Vleet John F. , Ferrans Victor J. , Badylak Stephen F.
Published: February 2025

Chronic doxorubicin (adriamycin; adr) intoxication was produced in Beagle dogs by weekly iv injections (1 mg/kg of body weight) for 20 weeks (cumulative dose 400 mg of adr/m2). Group A (5 dogs) were given adr only; group B (5 dogs), adr and daily supplements of 0.5 mg of L-thyroxine (T4) (twice the recommended maintenance dose); and group C (5 dogs), adr and 2.0 mg of T4 daily (8 times the recommended maintenance dose). The control group D (5 dogs) was given 0.5 mg of T4 daily. The adr-induced cutaneous lesions (alopecia and melanosis), body weight loss, hematologic alterations, and myocardial microscopic and ultrastructural alterations (sarcoplasmic vacuolation and myocytolysis) were present with equal severity in the 3 adr-treated groups, with or without T4 supplements. Six of the 15 adr-treated dogs died during the study: 3 dogs had pneumonia, 1 dog had no established cause of death, and 2 dogs (from group C) had lesions of congestive cardiac failure. All adr-treated dogs given a cumulative dose of 340 mg of adr/m2 or more had characteristic myocardial histopathologic alterations, but 2 dogs that died after they were given only 140 or 260 mg of adr/m2 had no microscopic evidence of myocardial damage.

Low serum triiodothyronine (T3) concentrations were present in adr-treated dogs after 28, 56, 84, 112, and 140 days and were attributed to faulty extrathyroidal conversion of T4 to T3. Serum T4 concentrations were high in dogs given 2 mg of T4/day (group C) after 28, 56, 84, and 112 days, but were low terminally as those dogs became debilitated from chronic adr toxicosis. Unusual clinical signs or cardiac alterations of hyperthyroidism did not develop in the dogs given T4 supplements (groups B, C, and D). Our findings indicate that supplements of T4 do not alter the development of the cardiac and extracardiac lesions of chronic adr toxicosis in dogs and indicate that the adr-induced lesions probably are not mediated via hypothyroidism.
Developmental stages of Dirofilaria immitis in the dog
Authors: Kotani Takao , Powers Kendall G.
Published: February 2025

Thirty-six Beagles were inoculated with 3rd-stage infective Dirofilaria immitis larvae to determine when 3rd and 4th molts occurred, how long each stage of development persisted in muscle and skin, and the patterns of larval migration from the infection site to the heart. From 22% to 84% of these larvae were recovered when the dogs were euthanatized and necropsied (mean recovery 45%). Larvae were recovered only from the skin and muscle during the first 58 days. The 5th-stage immature adults were first recovered from the heart in dogs killed on postinoculation day (pid) 70. Migration to the heart was essentially completed in dogs killed on pid 120, although 1 immature adult was recovered from subcutaneous tissues of each dog killed on pid 140 and 142. Starting and completion days of molting periods were recorded along with body lengths of male and female worms from the 3rd, 4th, and 5th stages. Microfilariae were first recovered from the peripheral blood in dogs killed on pid 190. Optimal time for drug evaluation against a particular stage of larval development is as follows: 3rd-stage larvae, pid 0 to 2; 4th-stage larvae, pid 15 to 50; and 5th-stage or immature adults, pid 65 to 120.
Reference serum pepsinogen concentrations in dairy cattle
Authors: Harvey-White J. D. , Smith J. P. , Parbuoni E. , Allen E. H.
Published: February 2025

Serum samples from 27 yearling heifers and 50 lactating cows were analyzed for pepsinogen concentration. Concentrations were 44 ± 12 (sd) ng of pepsinogen/ml (2,200 mU of tyrosine/ml) of serum for the yearling heifers and 20 ± 8 ng/ml (1,400 mU of tyrosime/ml) for the lactating cows. These initial data indicate that a yearling calf, grazing on pasture, with a serum pepsinogen concentration > 68 ng/ml (2,900) mU of tyrosine/ml) should be examined for ostertagiasis.
Effect of monensin on bovine ruminal 3-methylindole production after abrupt change to lush pasture
Authors: Carlson James R. , Hammond Andrew C. , Breeze Roger G. , Potchoiba Michael J. , Heinemann Wilton W.
Published: February 2025

The effect of monensin on ruminal 3-methylindole (3MI) production was investigated in cattle abruptly introduced to lush pasture. A field plot was fertilized, seeded, and irrigated to produce a lush pature. Thirty Hereford cows, fed poor quality hay for 3 weeks before the experiment, were assigned to 2 groups and were given access to lush pature on day 0. Cows in the monensin-treated group were given a daily capsule orally containing 200 mg of monensin, and cows in the nontreated group were given a placebo at daily intervals from day −1 to 7. Ruminal fluid and plasma were collected daily for analysis, and in vitro incubations with tryptophan were conducted on days −1, 1, 4, and 7. Ruminal pH and buffering capacity decreased on days 2 to 4 and then gradually increased, but there were no differences between treatment groups. Ruminal ammonia concentrations were lower (P < 0.05) on days 2 and 5 and ruminal indole was higher (P < 0,05) on days 1 and 2 in the monensin-treated group. Ruminal propionate concentrations were higher (P < 0.01) and acetate and butyrate lower (P < 0.01) on all days in the cows given monensin.

Ruminal 3MI concentrations increased after consumption of lush forage from an initial value of 1.4 ± 0.3 μg/ml, to 8.7 ± 0.5 and 4.9 ± 0.6 μg/ml on day 4, and decreased to 4.9 ± 0.3 and 3.0 ± 0.4 μg/ml on day 7 in nontreated and monensin-treated groups, respectively. Ruminal 3MI concentrations after pasture change were lower (P < 0.05) in the monensin-treated group on all days, except at day 10, which was 3 days after the last monensin dose. The reduction in ruminal 3MI concentration in the monensin group was greater from days 1 to 3 than from days 4 to 7. In vitro conversion of tryptophan to 3MI was lower (P < 0.01) in monensin-treated cows on days 1 and 4, but not on day 7. Seemingly, an increase in ruminal 3MI concentrations occurred in cows after abrupt change from poor quality hay to lush forage, and 3MI concentrations in monensin-treated cows were reduced. The greatest effect of monensin on reduction of 3MI production was observed within the first few days after administration.
Experimental bluetongue infections in gnotobiotic lambs and kids
Authors: Livingston C. W. , McConnell S. , Cummings G. , Gauer B. B.
Published: February 2025

Ten gnotobiotic lambs and 4 gnotobiotic kids inoculated with virulent bluetongue virus (btv) including btv international types 10, 11, 13, and 17 did not show clinical signs of bluetongue. Seroconversion was observed in all gnotobiotes and conventional control sheep inoculated with the appropriate challenge btv. Viremia was detected in 1 btv-infected gnotobiote. Conventional control sheep inoculated with a given btv international serotype showed a marked febrile response with hyperemia of the nasal and buccal mucosa.