bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of sodium heparin and antithrombin III concentration on activated partial thromboplastin time in the dog
Authors: Hellebrekers L. J. , Slappendel R. J. , van den Brom W. E.
Published: February 2025

Regulation of blood coagulation was studied in 12 dogs, using subcutaneous administration of sodium heparin. Dosage of heparin needed to achieve the desired 1.5- to 2.5-fold increase in the activated partial thromboplastin time (aptt) was 250 to 500 IU/kg of body weight. Increased aptt lasted < 6 hours. Repeated heparin administration, using the lowest dosage (250 IU/kg) every 6 hours, induced an unacceptable prolongation of clotting times during the first 2 days of treatment. Prolonged administration at a dosage of 200 IU/kg every 6 hours adequately maintained the desired hypocoagulative state initially; after 2 days, however, the prolonged aptt steadily decreased.

The decreasing effect was proportionate to a decrease in plasma antithrombin III (AT III). To sustain a correctly balanced hypocoagulative state from prolonged subcutaneous administration of heparin, aptt values should be determined regularly to monitor therapy. In addition, transfusion of AT III-rich donor plasma may be necessary when low plasma AT III reduces the effects of heparin.
Effects of various antidotal treatments on acetaminophen toxicosis and biotransformation in cats
Authors: Savides Michael C. , Oehme Frederick W. , Leipold Horst W.
Published: February 2025

Oral N-acetylcysteine (nac), iv nac, and iv sodium sulfate were evaluated as treatments for cats dosed orally with toxic sublethal doses of acetaminophen (apap). Six cats were given single oral doses of 120 mg of apap/kg of body weight and the respective antidote at 4.5, 8.5, and 12.5 hours after apap dosing in 3 separate trials. The cats were given each antidotal treatment in random order with at least 3 weeks separating the individual apap-treated trials. Clinical signs, plasma apap half-lives, clinical chemical values, and apap urinary excretion and metabolites were studied. Results were compared (P < 0.05) with each other and with those of a control group of 6 cats given identical apap doses, but given no antidotal treatment. At the dosage levels used, oral nac, iv nac, and iv sodium sulfate were equally effective antidotes, as measured by decreased methemoglobinemia, increased whole blood reduced glutathione, decreased apap half-lives, and increased urinary excretion of the apap-sulfate conjugate. All the antidotal treatments produced results significantly different from those in the control cats.
Pathologie changes in pigs with prednisolone-induced recrudescence of herpesvirus infection
Authors: Narita Minoru , Shimizu Mitsugu , Kawamura Hitoshi , Haritani Makoto , Moriwaki Masashi
Published: February 2025

In pigs inoculated with Aujeszky's disease virus (adv), recrudescence of herpesvirus infection was induced by daily administration of 1,000 mg of prednisolone for 5 days at 2 (group A) or 5 (group B) months after the primary infection. At necropsy in group A pigs, adv was recovered from nasal secretions 3 to 9 days after prednisolone treatment initiation and from the brain cortex 10 days after treatment initiation; adv was not recovered from group B pigs. In pigs of both groups killed 10 days after treatment initiation, 2 types of characteristic lesions were found. One type was a nonsuppurative encephalitis that consisted of neuronal necrosis, neuronophagia, and formation of eosinophilic intranuclear inclusion bodies. The 2nd type had basophilic intranuclear inclusion bodies in the enlarged endothelial cells of the kidneys, liver, lungs, adrenal glands, and lymph node sinusoids. Cells containing intranuclear inclusion bodies had immature and mature herpesvirus particles. Therefore, the brain lesions containing the eosinophilic inclusion bodies were considered to be due to adv. Basophilic inclusion bodies in the endothelial cells were due to porcine cytomegalovirus. These observations indicated that prednisolone treatment resulted in recrudescence of adv and porcine cytomegalovirus infections.
Effects of flunixin meglumine on blood pressure and fluid compartment volume changes in ponies given endotoxin
Authors: Dunkle N. J. , Bottoms G. D. , Fessler J. F. , Knox K. , Roesel O. F.
Published: February 2025

A study was conducted to determine whether body fluids undergo a net shift from one compartment to another during endotoxin-induced shock in the pony, and whether flunixin meglumine alters these endotoxin-induced changes in the volumes of body fluid compartments. Total blood, rbc, and plasma volumes were determined, using 51Cr-labeled rbc and pcv that were corrected for trapped plasma. Total body water was measured by distribution of 3HOH. Arterial blood pressure was measured directly, using a blood pressure transducer. Treatment (flunixin meglumine, 1.1 mg/kg of body weight) was given to 6 of the 12 ponies 1 minute before an iv injection of Escherichia coli endotoxin (100 μg/kg of body weight, ld100). The pcv and rbc volume increased in both groups; however, the hemoconcentration was less in flunixin meglumine-treated ponies. In nontreated ponies, total blood volume and plasma volume decreased significantly during the first hour after endotoxin administration. In treated ponies, total blood volume did not vary significantly, and plasma volume decreased only slightly. In both groups, the increase in pcv was apparently due to splenic contraction, which increased the number of circulating rbc. Hemoconcentration was further increased in nontreated ponies by the loss of plasma into the interstitial space. Flunixin meglumine reduced plasma loss, minimized hemoconcentration, and maintained normal blood volume. Total body water remained constant in treated and nontreated ponies.
Pathophysiologic study of 3-methylindole-induced pulmonary toxicosis in immature cattle
Authors: Lekeux P. , Hajer R. , van den Ingh T. S. G. A. M. , Breukink H. J.
Published: February 2025

In 5 Friesian calves given 3-methylindole (3-mi) (100 mg/kg once a week for 8 weeks, except calf 4, given a 50 mg/kg dose on weeks 3 to 8), pulmonary function (pf) values and arterial blood gas tensions (Pao2 and Paco2) were measured 24 hours after dosing was done and were correlated with clinical, biochemical, and pathologic changes.

Three of the calves (No. 1, 2, and 3) showed acute respiratory distress syndrome 24 hours after the first 3-mi treatment, with a large increase in respiratory frequency, minute viscous work, and Paco2 and a large decrease in tidal volume, dynamic lung compliance, and Pao2. They died 36, 38, and 84 hours after dosing.

Pulmonary function changes were compatible with the severe pulmonary edema and alveolar damage observed at necropsy. The 2 other calves, after they were given the 1st dose, showed only subacute respiratory distress syndrome with less severe changes in pf values recorded at 24 hours. Furthermore, they became progressively more tolerant to the 2nd, 3rd, and 4th weekly treatments, and showed base-line pf values after the 5th weekly treatment. Pathologic changes were not observed in lung biopsy material from these 2 animals at 2 and at 12 weeks after the 8th (or last) 3-mi treatment.
Cytoplasmic estrogen and progesterone receptors in canine endometrium during the estrous cycle
Authors: Johnston Shirley D. , Kiang David T. , Seguin Bradley E. , Hegstad Rebecca L.
Published: February 2025

Estradiol and progesterone receptors (er, pr) were characterized and measured in cytosols from canine endometrium, using saturation and sucrose-gradient centrifugation radioassays. Both receptors were demonstrated to be steroid- and tissue-specific saturable proteins, which bound the respective steroids with high affinity (dissociation constant [Kd]~10−9M). Serum estradiol, progesterone, and endometrial cytosol receptor concentrations and receptor-binding affinity were measured for 25 bitches from which samples were obtained at 5 stages of the estrous cycle (5 bitches each): anestrus (A), the 3rd day of proestrus (P3), the 3rd day of estrus (E3), the 12th day after onset of estrus (E12), and the 28th day after onset of estrus (E28). Mean (± sem) serum estradiol concentrations were 17.0 ± 2.2 (A), 55.4 ± 5.0 (P3), 89.4 ± 24.9 (E3), 41.0 ± 5.9 (E12), and 50.6 ± 3.9 (E28) pg/ml. Mean (± sem) serum progesterone concentrations were 0.4 ± 0.1 (A), 1.5 ± 0.2 (P3), 17.3 ± 7.5 (E3), 41.6 ± 9.5 (E12), and 25.8 ± 3.2 (E28) ng/ml. Concentrations of er increased significantly from 1.06 pmol/g of uterus during stage A to a peak concentration of 6.18 pmol/g of uterus at E12, followed by a gradual decrease to 0.69 pmol/g of uterus by E28. The pr concentrations increased from 3.01 pmol/g of uterus in stage A to 17.32 pmol/g of uterus at P3; pr concentrations, thereafter, decreased gradually to 1.85 pmol/g of uterus by E28. Dissociation constants were significantly higher at E12 for the er (Kd = 2.6645 × 10−9M) and at P3 for the pr (Kd = 5.8282 × 10−9M) than at the other stages examined, indicating a decrease in receptor affinity during the periods of high receptor concentrations. These data indicate that follicular estrogen induces er and pr formation in the dog as it does in other species. Second, decreases in serum estradiol concentrations and increases in serum progesterone concentrations are associated with decreases in receptor concentration.
Echocardiographic and clinical effects of milrinone in dogs with myocardial failure
Authors: Kittleson Mark D. , Pipers Frank S. , Knauer Kenneth W. , Keister D. Mark , Knowlen Grant G. , Miner William S.
Published: February 2025

Milrinone is a recently synthesized bypyridine compound with positive inotropic and arteriolar dilating properties in persons and experimental animals. To examine the efficacy and safety of milrinone to treat myocardial failure in dogs, dogs with myocardial failure were selected from the patient populations of 3 veterinary hospitals. Progressively increased dosages of milrinone, from 0.05 to 1.0 mg/kg of body weight, were administered over 14 days, and cardiac responses, as determined by M-mode echocardiography, and clinical responses were recorded. An effective dosage of milrinone was identified for each dog and administered for 4 weeks to evaluate the stability of the cardiac response. A randomized blinded study of drug vs nondrug capsule or nondrug elixer (designated placebo) was performed at the end of 4 weeks to eliminate possible effects of investigator bias or spontaneous regression of the disease. The duration of drug effect was determined by evaluating echocardiographic measurements of left ventricular function for 12 hours after drug administration.

Echocardiographic evaluation of left ventricular function improved in dogs given milrinone. The effective dosage was between 0.5 and 1.0 mg/kg. Tolerance to milrinone did not develop during the 4-week study. In dogs given placebo during the randomized blinded study, echocardiographic values decreased significantly. Dogs that were given milrinone remained echocardiographically stable. During the study, 6 dogs improved clinically, 5 remained the same, 1 had a decrease in exercise tolerance, 1 died of severe heart failure, and 1 died of hypoadrenocorticism. Ventricular tachydysrhythmia was exacerbated in 2 dogs, but was not treated. The drug effect lasted 12 hours, but was only 45% of maximum at 12 hours.

This study indicates that milrinone may be, in the future, an effective and safe drug for treating myocardial failure in the dog.
Vascularization of cancellous chip bone grafts
Authors: Wilson James W. , Rhinelander Frederic W. , Stewart Charles L.
Published: February 2025

Fresh autogenous, frozen allogeneic, and commercially prepared xenogeneic cancellous chip bone grafts were placed into plug holes in the tibia and into surgically simulated nonunion defects in the ulna of dogs. The microvascular and correlated histologic reactions were studied at given times up to 12 weeks after the graft implantation. Marked and characteristic differences were noted among the 3 graft materials. Fresh autogenous chips were extensively vascularized by 1 week, and subsequent microscopic healing was rapid. Allogeneic chips were incorporated into all defects, but vascularization and histologic healing rates were slower than those with the fresh autogenous graft material. The xenogeneic graft was poorly incorporated. A foreign body reaction was seen histologically, and corresponding vascularization of the graft was slow and incomplete.
Impaired function of bovine alveolar macrophages infected with parainfluenza-3 virus
Authors: Liggitt D. , Huston L. , Silflow R. , Evermann J. , Trigo E.
Published: February 2025

Bovine alveolar macrophages (bam) were harvested from nonsedated cattle, adhered to glass or plastic surfaces, and infected with parainfluenza-3 (pi-3) virus at a multiplicity of infection of 10. Control and pi-3 virus-infected bam were compared at 24-hour intervals up to 168 hours for their ability to phagocytize antibody-coated sheep erythrocytes (eac) and latex particles, to kill Staphylococcus epidermidis, and to alter intracellular acid phosphatase concentrations. The effect of antiviral serum on phagocytic functions of virus-infected cells was also evaluated. Compared with noninfected controls, alveolar macrophages infected with pi-3 virus were 15.3% less adherent to the glass or plastic surfaces at postinoculation hour (pih) 72 and were 64.0% less adherent at pih 168. Significant differences (P < 0.05) between the numbers of control and infected bam phagocytizing eac were observed at pih 24 through 72, with final values differing by approximately 50%. Similar changes were observed in the phagocytic efficiencies of individual cells. The pi-3 virus-infected bam that were exposed to antiserum or to immunoglobulins against pi-3 virus had approximately a 2-fold greater inhibition in eac phagocytosis than did infected bam exposed to serum without pi-3 activity. Significant differences in latex particle phagocytosis were not observed between infected and control bam. Compared with control bam, the pi-3 virus-infected bam contained significantly lower concentrations of acid phosphatase from pih 48 through 96; at pih 96, acid phosphatase concentrations were 4-fold less in infected than in control bam. Significant differences (P < 0.05) in bacterial killing between infected and control bam were not recognized until pih 168. Results of this study indicate that pi-3 virus can impair selected bam functions associated with defense of the lung,
Synergistic influence of Ostertagia ostertagi and Trichostrongylus axei on Ostertagia ostertagi larval inhibition and abomasal lesions in cattle
Authors: Snider Theron G. , Williams James C. , Karns Phillip A. , Trammell Herbert E. , Romaire Terry L.
Published: February 2025

Parasite-free 4-month-old calves were inoculated with Ostertagia ostertagi and/or Trichostrongylus axei followed 6 weeks later by increasing doses of O ostertagi for 8 weeks. Clinical signs of parasitism, fecal egg counts, and plasma pepsinogen concentrations were monitored, and gross lesions and parasite burdens were determined postmortem.

Clinical signs of parasitism were not observed and weight gains were not affected in experimentally infected calves. In calves infected with O ostertagi, mean plasma pepsinogen concentrations were greater than for control calves and were diagnostically significant 4 weeks after inoculation and during the last 4 weeks of serial inoculations with O ostertagi. In calves that were given O ostertagi and T axei, abomasal pH was significantly increased, and abomasal lesions were more pronounced than in control calves or in calves inoculated with only O ostertagi or T axei. Abomasal lymph nodes were enlarged in all parasitized calves; other lymph nodes in the calves inoculated with both O ostertagi and T axei were usually smaller than in calves inoculated with only O ostertagi or T axei. Numbers of O osfertagi-inhibited larvae were small in all inoculated calves, but the percentage inhibition was significantly greater in calves inoculated with both O ostertagi and T axei. The percentage inhibition was 3.53% for the O ostertagi-inoculated calves and 7.07% for calves inoculated with both O ostertagi and T axei. These percentages indicated a synergistic effect of concurrent abomasal parasitism, whereas a synergistic effect on T axei worm burden was not observed. The low percentage of larval inhibition indicated that factors other than host resistance are involved in naturally occurring pretype II ostertagiosis.
A porcine-murine hybridoma that secretes porcine monoclonal antibody of defined specificity
Authors: Raybould T. J. G. , Willson P. J. , McDougall L. J. , Watts T. C.
Published: February 2025

Spleen cells from a pig hyperimmunized with Escherichia coli were fused with nonproducer mouse plasmacytoma cells. Stable hybridoma lines secreting porcine immunoglobulins were obtained. One line secreted monoclonal porcine immunoglobulin G, which reacted specifically with E coli in an enzyme-linked immunosorbent assay and precipitated a polypeptide of molecular weight of 50,000. This is the first report of a stable porcine-murine hybridoma producing porcine antibody of defined specificity.
Correlative biomechanical and histologic study of the cranial cruciate ligament in dogs
Authors: Vasseur P. B. , Pool R. R. , Arnoczky S. P. , Lau R. E.
Published: February 2025

The mechanical properties of the cranial cruciate ligament were determined, using unilateral bone-ligament-bone preparations from 65 dogs of various ages and body sizes. Tensile loading of the cranial cruciate ligament from 1 of each pair of stifle joints demonstrated a decrease in material properties (modulus, maximum stress, strain energy) with aging. The decreases in maximum stress and strain energy with age were significantly less (P < 0.05 and P < 0.05, respectively) in the cranial cruciate ligament from dogs weighing < 15 kg, compared with those weighing 15 kg or more. The cranial cruciate ligament and remaining femorotibial ligaments were collected from the opposite stifle joints and examined microscopically. By 5 years of age, the cranial cruciate ligaments of dogs weighing > 15 kg consistently had microscopic evidence of degenerative disease (loss of ligamentocytes, metaplasia of surviving ligamentocytes to chondrocytes, and failure to maintain collagen fibers and primary collagen bundles) which progressed in severity with age. The caudal cruciate ligaments were similarly affected, although the degenerative changes were rarely as severe as in the cranial cruciate ligament. The collateral ligaments underwent minimal degeneration. Sex differences had no bearing on degeneration. The cranial cruciate ligaments in dogs weighing < 15 kg generally had less severe alterations than those in heavier dogs, and the onset of the degenerative process was delayed by several years. Cranial cruciate ligaments removed from dogs after ligament failure not only had degenerative disease, but also had undergone unsuccessful attempts at repair. In contrast, fibrous repair was rarely present in intact ligaments of asymptomatic dogs with degenerative disease of the cranial cruciate ligament.
Effects of graded pleural effusion on QRS in the dog
Authors: Rush J. E. , Hamlin R. L.
Published: February 2025

Six anesthetized healthy dogs were placed in right lateral recumbency. Electrocardiographic leads I, aVF, V10, rV3, V3, and V5 were obtained during a control period and after introduction of pleural effusions ranging between 0.66 and 55 ml of isotonic saline solution/kg of body weight. Peak-to-peak amplitudes of QRS were measured, and the effusion required to decrease this amplitude by more than 1 sd from the mean of healthy dogs was determined for each lead tested.

Sensitivity of detecting pleural effusion was greatest in lead I in which an effusion of 2.75 ml/kg could be detected. The QRS amplitudes in leads V10 and aVF were decreased to a significant level only at large effusions. Leads V3 and V5 were “blind,” even to the greatest pleural effusions.

Radiographs taken with the graded pleural effusion documented that the heart “floated” away from rV3 and toward V3 and V5, thus explaining the sensitivity of rV3 and insensitivities of V3 and V5. It seems that pleural effusion can be detected by using these leads in dogs in right lateral recumbency, that detection is best if serial recordings are taken, and that relatively high sensitivities are achieved using lead I.
Effects of calcium supplementation and sunlight exposure on growing Beagle dogs
Authors: Stephens L. C. , Norrdin R. W. , Benjamin S. A.
Published: February 2025

Nine 7-week-old Beagle dogs were given 2.3 g of dietary calcium supplementation once a day and were exposed to sunlight to permit endogenous vitamin D formation. After 70 days, the serum calcium and phosphorus concentrations, thyroid morphometry, and bone density and composition were compared with those values in a similar group of 10 dogs not given calcium supplementation and maintained in restricted, artificial light. Lower serum calcium and phosphorus concentrations in the supplement-fed dogs may be attributed to hypercalcitonism, which was assumed to be present because of increased proportions of C cells and decreased proportions of thyroid follicles. They also had significantly more trabecular bone of a lower specific gravity containing more water and less combustible matter.

The findings indicate that the high dietary calcium intake and sunlight exposure induced C-cell hyperplasia during a relatively short period of 70 days. It is possible that Beagles maintained through maturity on a diet high in calcium concentration and in outdoor runs may develop chronic C-cell hyperplasia. The possible contribution of high calcium intake and chronic C-cell hyperplasia to reduced thyroid function and skeletal changes is not yet clear.
Determination of serum bile acids in fasting dogs with hepatobiliary disease
Authors: Johnson Susan E. , Rogers William A. , Bonagura John D. , Caldwell James H.
Published: February 2025

The diagnostic value of determining total conjugated serum bile acid (sba) concentrations was evaluated in fasting dogs with spontaneous liver disease. Conjugated primary sba values were determined by radioimmunoassay in 12 healthy dogs, 64 dogs with hepatobiliary disease, and 9 dogs with intestinal disorders unassociated with clinical or biochemical evidence of liver disease. Reference values for sba concentrations ranged from 0 to 5 µmol/L and were not significantly different from those determined in dogs with intestinal disease (P < 0.05). Mean sba concentrations determined in dogs with portosystemic shunts, glucocorticoid-induced hepatopathy, hepatic neoplasia, hepatitis, cholestasis, and cirrhosis were significantly greater than reference values (P < 0.05). The mean sba concentration in dogs with glucocorticoid-induced hepatopathy was significantly (P < 0.05) lower than that in all other clinical groups of dogs with liver disease, except in dogs with cholestasis, Although these 2 groups were statistically indistinguishable, dogs with glucocorticoid-induced hepatopathy generally had lower sba values (2 to 37 µmol/L) than did the group with cholestasis (2 to 562 µmol/L), The sba concentrations in fasting dogs were weakly correlated with histologic evidence of hepatic damage, as determined by a total biopsy score (r = 0.28, Ρ < 0.02). Because total sba concentrations were increased in 89% of all dogs with hepatobiliary disease, the determination of sba appears to be a sensitive test of hepatic dysfunction.
Japanese encephalitis virus immunoglobulin M antibodies in porcine sera
Authors: Burke D. S. , Tingpalapong Markapol , Elwell M. R. , Paul P. S. , Van Deusen R. A.
Published: February 2025

A solid-phase enzyme-linked immunosorbent assay (elisa) was developed for detection of porcine immunoglobulin (Ig)M antibodies to Japanese encephalitis virus (jev). Antibodies in sera were captured onto the solid phase of Microtiter plates sensitized with mouse monoclonal antibodies to porcine µ heavy chain. Virus antigen binding to the lawn of IgM was quantitated by subsequent binding of peroxidase-labeled human hyperimmune anti-jev IgG, which in the final step, catalyzed a substrate color change.

In sucrose density-gradient fractionated sera from recently infected pigs, the peak of elisa jev IgM activity corresponded to the peak of 18-S, 2-mercaptoethanol-sensitive hemagglutination-inhibiting (hai) antibody activity. Within 2 to 3 days, jev-infected sentinel pigs developed high jev IgM activity; this activity decreased within 2 weeks.

Among specimens collected from 99 random swine at abattoirs in Thailand during a period of low jev transmission, none of 25 jev hai-negative sera had jev IgM activity, 7 of 74 jev hai-positive sera did have jev IgM activity, and the remaining 67 sera had readily detectable jev hai antibodies, but lacked jev IgM. The jev IgM solid-phase elisa was useful for rapidly diagnosing active or recent jev infections in swine.
Comparison of suture materials and suture patterns for inverting intestinal anastomosis of the jejunum in the horse
Authors: Dean Paul W. , Robertson James T. , Jacobs Robert M.
Published: February 2025

In 7 horses, 4 anastomoses were done in the small intestine in each, using the combinations of synthetic absorbable monofilament and multifilament suture materials with continuous- and interrupted-suture patterns in the serosubmucosal layer of a 2-layer inverting-suture technique. Horses were evaluated 30 days after the operation for adhesion formation, lumen diameter, evidence of chronic obstruction, and suture tract inflammation at the anastomosis.

Postoperative obstruction occurred in 5 of the 7 horses, and 6 horses survived. One horse was euthanatized oh postoperative day 6 after 48 hours of ileus and obstruction; necropsy revealed a partial intussusception involving the anastomosis done with continuous multifilament suture material. Two other horses that became obstructed between postoperative days 3 and 5 had protracted ileus and gastric reflux up to 48 hours' duration, but survived. Horses that had obstruction after the 6th postoperative day recovered within 4 hours of onset.

The continuous inverting-suture pattern in the serosubmucosal layer resulted in significantly (P < 0.05) fewer adhesions than did the interrupted pattern, and suture material had no effect on adhesion formation. There was no significant difference in the percentage of reduction of lumen diameter between the variations of the 2-layer technique, and there was no evidence of chronic obstruction related to any of the anastomoses. Suture tract inflammation was moderate in the anastomoses, using continuous-multifilament suture, with neutrophils being the predominant cell type. The anastomoses with continuous-monofilament suture had mild inflammation with focal accumulations of neutrophils. Minimal inflammation was associated with both types of suture in the interrupted pattern.
Comparison of the herpesviruses of cattle by DNA restriction endonuclease analysis and serologic analysis
Authors: Osorio F. A. , Reed D. E. , Van der Maaten M. J. , Metz C. A.
Published: February 2025

Reference strains and field isolates of herpesviruses recovered from cattle in the United States were compared by restriction endonuclease (re) analysis and the indirect fluorescent antibody test. As a result of these comparisons, 5 major biotypes of bovine herpesvirus (bhv) were defined. These types were (i) infectious bovine rhinotracheitis virus (bhv-1), (ii) bovine herpes mammillitis virus (bhv-2), (iii) malignant catarrhal fever (mcf) virus (herpesvirus alcelaphinae), (iv) the group of slow-growth isolates represented by the prototype strain Movar 33/63 (bovine cytomegalovirus candidate), and (v) the syncytia-forming Pennsylvania 47 strain. Bovine herpesvirus-1 and bhv-2 did not cross-react serologically with any other type of bhv tested. A low, but consistent level of serologic cross-reactivity was detected among mcf virus, the Movar group, and Pennsylvania 47. Several nonsyncytial, slow-growth strains, which were recovered from dissimilar clinical syndromes and were serologically related to Movar 33/63, exhibited similar DNA re cleavage patterns, confirming their identity as members of a single type. There was no isolate from American domestic cattle similar to the African mcf virus, which has been sporadically isolated from exotic ruminants in the United States. The African mcf virus isolated during a mcf epizootic in a United States zoo exhibited some DNA re cleavage differences in comparison with the mcf virus world prototype strain WC 11, indicating that strain diversity exists within this biotype.
Normal and collapsed trachea in the dog: Scanning electron microscopy study
Authors: Dallman Mark J. , McClure Robert C. , Brown Esther M.
Published: February 2025

Scanning electron microscopy was used to examine canine tracheal cartilage and to determine the relationship between the fibrous and amorphous matrix in this tissue. Collapsed tracheal (ct) cartilage was hypocellular, compared with normal tracheal cartilage. The amorphous matrix of ct cartilage had a porous, fissured texture and did not have the homogeneous appearance of normal tracheal cartilage. Capillaries were seen to pass through ct cartilage. Randomly distributed connective tissue fibers, evident in ct cartilage matrix, were frequently attached to irregular shapes and sizes of amorphous matrix.
Effect of disulfiram in experimentally induced vitamin Ε deficiency myopathy in lambs
Authors: Steiss Janet E.
Published: February 2025

Vitamin Ε deficiency myopathy (white muscle disease) was induced in 14 suckling lambs (2 experiments; 7 lambs/experiment) by addition of cod liver oil to the diet. Disulfiram, an antioxidant, was administered orally once each day to 8 of the 14 lambs at 2 different doses. Serum creatine kinase (ck) activity was measured weekly for 5 weeks. Increased ck activity was evident in some lambs beginning at week 3. By week 4, serum ck was abnormally increased in 5 of the 6 nontreated lambs (ie, disulfiram not given) and in 4 of the 8 treated lambs. The combined disulfiram groups had significantly lower serum ck values during the study (P < 0.05). Serum α-tocopherol, measured on samples from week 5 for lambs of experiment 1, was significantly higher in treated lambs (P < 0.01). Microscopic examination of the vastus lateralis muscle indicated that the most severe lesions, consistent with nutritional myopathy, were seen in nontreated lambs. Therefore, disulfiram may have an antioxidant effect in lambs with vitamin Ε deficiency.
Enteropathogenicity of purified Clostridium perfringens enterotoxin in the pig
Authors: Popoff M. R. , Jestin A.
Published: February 2025

In an assay procedure, purified Clostridium perfringens enterotoxin induced the accumulation of fluid in the ileal loop of the axenic pig. The smallest amount of enterotoxin causing a positive response was 25 µg (1:32 titer by counterimmunoelectrophoresis [ciep]), and 100 µg (1:128 ciep titer) caused a marked response. Possibly, diarrhea in pigs with 1:32 ciep titer or more of enterotoxin in the feces may be associated with enterotoxigenic C perfringens.
Passive transfer failure in horses: Incidence and causative factors on a breeding farm
Authors: Morris Debra Deem , Meirs David A. , Merryman Geralyn Schad
Published: February 2025

A prospective study was performed to determine the incidence and associated maternal and managemental factors of failure of passive transfer (fpt) in foals on a breeding farm. The zinc sulfate turbidity test (zstt) and latex agglutination test (lat) were compared for accuracy in estimating serum immunoglobulin (Ig)G of foals, as determined by single radial immunodiffusion (srid). Complete past and present foaling histories of 136 Standardbred mares were obtained. All foalings were witnessed by farm attendents, and colostral samples were collected from mares within 2 hours after parturition. Foals that did not rise and nurse were supplemented with colostrum from the dam, using a bottle or nasogastric tube. Serum samples were prepared from foals and mares between 24 and 36 hours after parturition, and from some mares 45 to 90 days before parturition. Serum IgG concentrations of mares and foals and colostral whey were determined, using srid. Serum IgG also was estimated in foals, using zstt and a commercially available lat. Four of the 136 foals (2.9%) had fpt (serum IgG ≤ 400 mg/dl), Serum IgG concentrations in foals significantly correlated with colostral IgG (P < 0.001). A significantly larger proportion of foals with fpt were bottle-fed their colostrum (P < 0.01). Month of parturition, mare age, parity, number of barren seasons, incidence of assisted births or retained placenta, or prepartum serum IgG concentrations did not significantly affect colostral IgG concentrations or serum IgG concentrations in foals. As serum IgG concentrations in foals decreased and as colostral IgG concentrations decreased, the proportion of mares that prelactated significantly (P < 0.01) increased, A significant positive correlation was found between postpartum serum IgG and colostral IgG in mares that did not prelactate (P < 0.05). Immunization of mares for salmonellosis during gestation was positively correlated with higher colostral IgG concentrations (P < 0.05). A significant agreement was found between zstt, lat, and srid for estimation of serum IgG concentrations in foals (P < 0.001). For determination of serum IgG concentrations in foals, zstt results highly correlated with srid results; however, lat results were significantly more accurate for estimation of serum IgG concentrations ≤ 400 mg/dl (P < 0.001) than were zstt results.
Studies on the pathogenesis of Salmonella heidelberg infection in weanling pigs
Authors: Reed Willie M. , Olander Harvey J. , Thacker H. Leon
Published: February 2025

Experiments were conducted to define the pathogenic potential of Salmonella heidelberg in weanling pigs.

Oral inoculation with S heidelberg resulted in severe catarrhal enterocolitis with accumulation of large amounts of fluid in the small intestine and colon. Salmonella heidelberg was demonstrated, with fluorescence microscopy and bacteriologic cultural techniques, to colonize the ileum, to invade ileal mucosal enterocytes, and to reach mesenteric lymph nodes and extraintestinal tissues by 8 hours.

In 5 pigs, intestinal loops were surgically prepared and inoculated with S heidelberg (to determine its invasiveness), Microscopically, there were atrophy of villi, erosion of enterocytes, and neutrophilic infiltration in the lamina propria, Ultrastructurally, intracellular bacteria were demonstrated in villous and cryptal enterocytes, as well as in macrophages of the lamina propria. Bacteria were morphologically intact, occurred free and membrane-bound, and caused no detectable cytotoxic effect to the cell.
X-ray powder diffraction and microscopic analysis of crystalluria in dogs with ethylene glycol poisoning
Authors: Foit Franklin F. , Cowell Rick L. , Brobst Duane F. , Moore Michael P. , Tarr Bryan D.
Published: February 2025

SUMMARY AND CONCLUSIONS

Most of the urinary crystals in 2 dogs intoxicated with ethylene glycol had prismatic (rod-like, hippurate-like), and to a less extent, hemp seed or spindle shapes. Using X-ray powder diffraction and optical analysis, these crystals were identified as calcium oxalate monohydrate. A few crystals of calcium oxalate dihydrate (envelope shape) were also observed in the urine sediment. Their presence was confirmed by the appearance of weak X-ray peaks having interplanar spacings ranging from 0.617 to 0.620 nm, which are thought to correspond to the 200 X-ray reflection of calcium oxalate dihydrate.

Thus, the 6-sided hippurate-like crystals in the urine of ethylene glycol-poisoned dogs are actually calcium oxalate monohydrate.
Thresholds of the dog for detection of inhaled eugenol and benzaldehyde determined by electroencephalographic and behavioral olfactometry
Authors: Myers Lawrence J. , Pugh Ross
Published: February 2025

Electroencephalographic olfactometry and behavioral olfactometry were developed to evaluate objectively the olfactory function of 12 dogs. These techniques were used to determined normative thresholds for benzaldehyde, a mixed olfactory and trigeminal stimulant, and eugenol, a suspected pure olfactory stimulant, in 12 dogs. Both techniques were effective in obtaining a mean threshold for clinically normal dogs. Electroencephalographic olfactometry was demonstrated to be more sensitive than was behavioral olfactometry. The techniques measured olfactory function by failure to evoke responses in dogs after ablation of olfactory mucosa. The contribution of trigeminal stimulation to the thresholds was not determined.
Characterization of Mycobacterium paratuberculosis antigenic proteins
Authors: Bech-Nielsen Steen , Burianek Linda L. , Spangler Elisabeth , Heider Lawrence E. , Hoffsis Glen F. , Dorn C. Richard
Published: February 2025

The characterization of a purified antigen from Mycobacterium paratuberculosis, recently made commercially available for use in serodiagnosis by enzyme-linked immunosorbent assay (elisa), of paratuberculosis in cattle was described. This assay had 89% specificity and 83% sensitivity for M paratuberculosis infection. The protein/polypeptide composition of the purified antigen was compared with that of a crude protoplasmic extract of strain 18 M paratuberculosis used in the agar-gel immunodiffusion test and elisa and with that of sonicated strain 19698 M paratuberculosis organisms grown on Dorset-Henley synthetic liquid medium. The sonicated M paratuberculosis contained 27 major proteins/polypeptides; the crude protoplasmic extract, 18; and the purified antigen contained 14 proteins/polypeptides, using sodium dodecyl-sulfate polyacrylamide-gel electrophoresis analysis.

The serologic reactivity of these proteins/polypeptides were defined, using the enzyme-linked immunoelectrotransfer blot technique. The sonicated M paratuberculosis contained 20 serologically reactive proteins/polypeptides (34,000 to 84,000 daltons); the crude protoplasmic extract contained 3 (37,000 to 45,000 daltons); and the purified extract contained a diffuse polypeptide band (34,000 to 38,000 daltons). Identification by enzyme-linked immunoelectrotransfer blot technique of M paratuberculosis antigens reactive in the elisa will allow us to further study these antigens in the elisa to improve sensitivity and specificity of the diagnostic test.
Cerebral, renal, adrenal, intestinal, and pancreatic circulation in conscious ponies and during 1.0, 1.5, and 2,0 minimal alveolar concentrations of halothane-02 anesthesia
Authors: Manohar Murli , Goetz Thomas E.
Published: February 2025

Blood flow to the brain, kidneys, adrenal glands, pancreas, and small intestine was studied in 8 healthy ponies while awake (control) and during 1.0, 1.5, and 2.0 minimal alveolar concentrations (mac) of anesthesia produced, using halothane vaporized in oxygen. During the anesthesia steps, intermittent positive-pressure ventilation was used to ensure isocapnia. Organ blood flow was determined with 15-μm (diameter) radionuclide-labeled microspheres, after allowing 30 minutes of equilibration at each of the 3 preestablished end-tidal halothane concentrations. The sequence of 1.0, 1.5, and 2.0 mac levels of anesthesia (0.90, 1.35, and 1.80% end-tidal halothane) was randomized for every animal.

In the awake ponies, cerebral blood flow in the cortical (106 ± 15 ml/min/100 g) and deep gray (103 ± 12 ml/min/100 g) matter was approximately 5-fold of that in the white matter (22 ± 3 ml/min/100 g). In the brain stem, there was a decreasing gradient of blood flow from the cranial (thalamohypothalamus; 65 ± 8 ml/min/100 g) to caudal regions (medulla: 34 ± 5 ml/min/100 g).

Vasodilatation occurred in all regions of the brain with halothane-02 anesthesia; the decrease in vascular resistance reached its nadir at 1.5 mac. In the medulla and pons, blood flow increased above control values, with each of the 3 concentrations of halothane, but in the midbrain and thalamohypothalamus, it remained similar to the control value. In the cerebral white matter and cerebellum, blood flow increased with 1.0 and 1.5 mac of halothane anesthesia, whereas mean aortic pressure decreased to 91% and 74% of the control value. Blood flow in the cerebral cortex was not different from the control value, even at 2.0 mac of halothane, despite a 49% reduction in perfusion pressure.

Renal blood flow decreased from its control value (483 ± 79 ml/min/100 g) with each concentration of halothane; at 2.0 mac, renal vascular resistance increased markedly. Marked dilatation occurred in the adrenal gland vasculature during halothane anesthesia, and at 1.0 and 1.5 mac, adrenal blood flow was significantly increased. The pancreatic and small intestinal vasculature exhibited intense vasoconstriction during each level of halothane-O2 anesthesia.

It is concluded that in ponies anesthetized with halothane-O2, vasodilation occurred in the cerebrum, cerebellum, brain stem, and adrenal glands, whereas intense vasoconstriction occurred in the pancreatic and small intestinal vasculature. Renal blood flow decreased in halothane-anesthetized ponies.
Theophylline and dyphylline pharmacokinetics in the horse
Authors: Ayres James W. , Pearson Erwin G. , Riebold Thomas W. , Chang Shyi-Feu
Published: February 2025

The pharmacokinetics of theophylline and dyphylline were determined after iv administration in horses. In a preliminary experiment, the usual human dosage (milligram per kilogram) of each drug was given to 1 horse. Results were used to calculate dosages for a cross-over study, using 6 horses for each drug.

Theophylline plasma concentrations decreased triex-ponentially in 5 of 6 healthy horses after iv infusion of 10 mg of aminophylline/kg of body weight for 16 to 32 minutes. In the 6 horses, total body elimination rate constants were variable, and the half-life of theophylline was 9.7 to 19.3 hours. Clearance was 42.3 to 69.2 ml/hr/kg. The initial distribution phase was rapid (t½ approx 3.5 to 4 minutes); a 2nd distribution phase was slower (t½ approx 1.5 to 2 hours). Plasma concentrations of theophylline were in the assumed effective range (10 to 20 (μg/ml) from 15 minutes until 40 minutes after time zero. The mean apparent volume of distribution was 1.02 L/kg.

After bolus iv injection of dyphylline (20 mg/kg), pharmacokinetics were best described by a 2-compartment open model in 2 horses and by a 3-compartment open model in 4 horses, In the 6 horses, elimination half-life of dyphylline was 1.9 to 2.9 hours, and clearance was 200 to 320 ml/hr/kg. Plasma concentrations (approx 50 μg/ml) were observed at 10 minutes after injection without adverse effects. Concentrations > 10 μg/ml were observed from time zero to about 1.5 hours after injection.

Theophylline induced significant increases in heart rate, but dyphylline did not affect heart rate significantly. Systolic, diastolic, and mean arterial blood pressures were decreased by theophylline and by dyphylline, with theophylline generally inducing greater decreases than did dyphylline. Neither drug had a significant effect on arterial oxygen tension, carbon dioxide tension, or bicarbonate in the horses evaluated.
Use of oxibendazole for control of cambendazole-resistant small strongyles in a band of ponies: A six-year study
Authors: Drudge J. H. , Lyons E. T. , Tolliver S. C. , Swerczek T. W.
Published: February 2025

Oxibendazole (obz; 10 mg/kg of body weight) was administered to ponies at 8-week intervals to control strongylosis in a breeding band of Shetland-type ponies (n = 29 to 50) from October 1978 through September 1984. A similar use of cambendazole (cbz; 20 mg/kg of body weight) in this band of ponies during the preceding 4-year period resulted in the survival of a cbz-resistant population (S) of small strongyles. Effectiveness of obz treatments was monitored by pre- and posttreatment counts of the number of strongyle eggs per gram of feces (epg) and of the number of strongyle larvae per gram of feces (lpg). For the First 4 years of the 6-year period, epg and lpg counts were determined for 3 to 5 of the obz treatments; during the last 2 years, counts were determined for each treatment. For the 1st year, the mean reduction in epg was 96%. During the 2nd and 3rd years, mean reductions in epg were 80% and 81%, respectively. For the 4th and 5th years, mean reductions in epg were 69% and 43%, respectively. For the 6th year, the mean reduction in epg was 37%. Statistical analyses of the epg data, using the linear plateau method, indicated a significant increase in residual (surviving) strongyle infections after the periodic obz treatments, with a mean annual increase in survival of 10.3% for the 6 years. Changes in lpg were variable, but an overall loss of effectiveness of the obz treatments was evident. Only infective larvae of small strongyles were observed in the cultures; larvae of 2 species of large strongyles, Strongylus vulgaris and Strongylus edentatus, were conspicuously absent. Dynamics of the process of resistance selection by obz was gradual and in a stair-step fashion. A mean appreciable activity of 40% was retained for the 5th and 6th years; in the previous 4-year period in which cbz was used, strongyle activity of cbz rapidly decreased during the 2nd year and was nearly inactive during the 3rd and 4th years. This ineffectiveness of cbz persisted after a hiatus of nearly 3 years of obz use, when cbz was evaluated once again in the present, study.

Foaling rates in the brood mares were 32% to 58% during the 5 seasons evaluated. Four abnormal foals were born, 1 each in 1980, 1982, 1983, and 1984. These deformities were categorized as genetic in origin, in contrast with the teratologic-type deformities previously associated with the use of cbz in this band.
Experimental infection of pregnant and lactating goats with Leptospira interrogans serovars hardjo and szwajizak
Authors: Tripathy D. N. , Hanson L. E. , Bedoya M. , Mansfield M. E.
Published: February 2025

Pathogenesis of 2 Leptospira serovars, hardjo and szwajizak, was studied in pregnant and lactating goats. Although clinical signs of leptospiral infection were minimal, cultural isolations were made from the mammary gland of 2 goats and the kidney of 1 goat inoculated with serovar hardjo (C846). The isolations were made only on solid bovine albumin polysorbate-80 medium supplemented either with rabbit serum or sodium pyruvate.

Cultural isolations of serovar szwajizak were made from kidney, liver, brain, urine, and mammary gland samples of 1 goat and the liver and kidney samples of its kids. These isolations were made in only the solid bovine albumin polysorbate-80 medium which had been supplemented with normal goat serum.
Pharmacokinetics of gentamicin in channel catfish (Ictalurus punctatus)
Authors: Setser Mark D.
Published: February 2025

The pharmacokinetics of gentamicin were determined in male and female Ictalurus punctatus weighing between 0.3 kg and 1.7 kg. Plasma gentamicin concentrations were measured by radioimmunoassay technique.

In the 1st experiment, an intracardiac bolus dosage of gentamicin (1 mg/kg) was given to 10 channel catfish. Samples of blood were obtained (by cardiac puncture) immediately before gentamicin was given and at various times over a 24-hour period. The gentamicin half-life was 770 minutes (β = 0.0009 ± 0.0003 minute−1). The maintenance therapeutic IV dosage of gentamicin was calculated to be 1.6 mg/kg given at 33.2-hour intervals.

In the 2nd experiment, an im dosage of the drug (1 mg/kg) was given to 9 channel catfish, and samples of blood were obtained at various times over a 24-hour period. The gentamicin half-life was 770 minutes (β = 0.0009 ± 0.0002 minutes−1). The maintenance therapeutic IM dosage of gentamicin was calculated to be 3.5 mg/kg given at 33.2-hour intervals. The IM bioavailability of gentamicin in channel catfish was estimated to be 60%. Other pharmacokinetic values were also determined.

It was concluded that the therapeutic regimen of choice for gentamicin in channel catfish was 3.5 mg/kg given im with 33-hour intervals between doses.