bluuebunny/crossref_metadata_2025 huggingface dataset:
Ultrastructure of equine endothelial cells exposed to endotoxin and flunixin meglumine and equine neutrophils
Authors: Turek John J. , Lamar Carlton H. , Fessler John F. , Bottoms Gerald D.
Published: February 2025

An in vitro system of cultured equine endothelial cells was evaluated as a model for endotoxin (et) exposure in the horse. Primary cell lines from pulmonary vessels and aortas were cultured from tissues of 6 horses. Effects of et alone with and without serum and in combination with the cyclo-oxygenase inhibitor flunixin meglumine and isolated equine neutrophils were evaluated by transmission electron microscopy. Cells plus serum were incubated with 10, 25, 50, or 100 μg of et/ml of incubation medium for 1, 3, 8, or 24 hours. Cells without serum were cultured for 1 and 3 hours. Flunixin meglumine was used at a concentration of 20 μg/ml. Cells also were incubated in the presence of 1,000, 5,000, or 20,000 neutrophils/ml plus et and in the presence of a combination of et and flunixin meglumine for 1 or 3 hours.

Endotoxin alone did not cause cell damage, and the only evidence of an effect was an increased number of secondary lysosomes at incubation hour 8. At incubation hour 24, cells appeared normal. Endotoxin plus neutrophils caused cells to become round and detach from the growth substrate. Cell pathologic changes included swollen and distorted mitochondria and cytoplasmic vacuolization. Response to the et plus neutrophil combination was variable and ranged from 5% to 50% of the cells being affected. The variability appeared to have some correlation with cell age, as well as individual preparation of neutrophils.
Autumn acquisition of nematodes by calves given a morantel sustained-release bolus the preceding spring
Authors: Yazwinski T. A. , Newby T. J. , Greenway T. E.
Published: February 2025

Reinfection with nematodes late in the grazing season was assessed in calves treated the preceding spring with a morantel sustained-release bolus (msrb). During an initial 155-day grazing period, msrb-treated calves (n = 15) grazed a pasture used the preceding year for identically treated calves (msrb pasture). Control calves (n = 15) were not given anthelmintic treatment in the spring and grazed heavily contaminated herbage for the initial 155-day period (control pasture). At the end of the initial grazing period, 3 calves from each group were killed for parasite recovery and counting, with control calves found to harbor 9.2 times more nematodes, compared with the msrb-treated calves. Nematode counts from tracers killed periodically during the initial grazing period were of similar proportions, reflecting the much greater nematode exposure experienced by the control calves, compared with the msrb-treated calves.

At the end of the initial grazing period, 10 calves (5/ group) were placed on a common, contaminated pasture after all were treated twice with fenbendazole (10 mg/kg of body weight, 7 days apart) while on concrete. The second grazing period was for 29 days, followed by a 3-day confinement on concrete. Then, the calves were killed and necropsied. During the 29-day grazing period, the msrb-treated calves maintained their weight advantage over the control calves, and significant differences in nematode egg counts were not found between the 2 groups of calves. At necropsy, the msrb-treated calves harbored 27.9% fewer nematodes than did the controls, indicating that prior therapeutic and prophylactic anthelmintic activities of the msrb did not predispose the animals to enhanced acquisition of nematodes after msrb protection.
Imidocarb and parvaquone in the treatment of piroplasmosis (Babesia equi) in equids
Authors: Kuttler K. L. , Zaugg J. L. , Gipson C. A.
Published: February 2025

The therapeutic efficacies of imidocarb and parvaquone were tested against Babesia equi of European origin in carrier horses and for induced acute infections in splenectomized ponies.

Imidocarb, at a dosage of 4 mg/kg of body weight, given im at 72-hour intervals 4 times, was ineffective in eliminating B equi-carrier infection in 9 mature geldings. A single im administration of 4 mg/kg was not therapeutic in acutely infected splenectomized ponies. When given at 3 different dosages and treatment schedules, parvaquone was ineffective in clearing carrier infection. Parvaquone given im once at a dosage of 20 mg/kg was effective for acute B equi infections in splenectomized ponies; parasitemia began to decrease within 24 hours after treatment. Infections were not eliminated however, and within 4 weeks, secondary parasitemia and anemia developed. Of 4 ponies, 3 died of acute piroplasmosis.
Comparison of various anesthetic regimens in the domestic fowl
Authors: Christensen Jan , Fosse Richard T. , Halvorsen Ole Johan , Morild Inge
Published: February 2025

Three anesthetic agents (equithesin, metomidate, and ketamine) combined with diazepam were tested in the domestic fowl. Laparotomy and thoractomy were possible with the equithesin/diazepam combination, but only laparotomy was possible with the metomidate/diazepam combination. The combination of ketamine/diazepam did not result in the depth of anesthesia required for surgical procedures. Repeated blood pressure and heart rate measurements were recorded by use of a modified noninvasive Doppler technique.

Equithesin/diazepam was our combination of choice for long-duration surgical anesthesia. The depth of anesthesia could be modulated by increasing the dose of diazepam. Metomidate/diazepam was useful when short-term anesthesia was required. In contrast to equithesin/diazepam, the metomidate/diazepam combination provided unstable anesthesia of varying depth and duration. Adverse reactions with metomidate indicated caution when using this drug in chickens; the drug also caused marked bradycardia. Ketamine/diazepam combination cannot be recommended as an anesthetic agent for use in chickens. The combination may be useful for minor surgical procedures or treatment, but not for experimental procedures that involve major surgery. Diazepam alone had a slight tranquilizing effect.
Photosensitization of cattle in southeast Texas: Identification of phototoxic activity associated with Cooperia pedunculata
Authors: Rowe Loyd D. , Norman James O. , Corrier Donald E. , Casteel Stan W. , Rector Barron S. , Bailey E. Muri , Schuster Joseph L. , Reagor John C.
Published: February 2025

A microbiological assay (Candida albicans) was used to screen plants in southeast Texas where bovine photosensitization (ps) of unknown cause was a recurring problem. Phototoxic activity was identified associated with dead leaf tips of Cooperia pedunculata, a native, perennial forb of the Amaryllis family (Amaryllidaceae) from central, southeast, and south Texas and parts of Mexico. A syndrome compatible with naturally occurring ps in cattle was induced in laboratory mice after oral administration of dead leaf material from Cpedunculata. Availablility and phototoxic activity of dead leaf material of C pedunculata corresponded with occurrence of ps in cattle. Seemingly, C pedunculata was involved in recurring ps.
M-mode echocardiographs of endurance horses in the recovery phase of long-distance competition
Authors: Bertone Joseph J. , Paull Kimberly S. , Wingfield Wayne E. , Boon June A.
Published: February 2025

M-mode echocardiographic structures, and cardiac function indices, pcv, and total plasma protein values were determined for 34 endurance equine athletes before (base line) and after (after race) a 161-km endurance competition and were compared. The pcv (base-line mean, 37%; after-race mean, 46%) and total plasma protein value (base-line mean, 6.9 g/dl; after-race mean, 7.5 g/dl) increased. Compared with base-line echocardiography, after-race echocardiography indicated an increase in heart rate, as determined from the simultaneous ecg recorded on the echocardiograph (base-line mean, 41 beats/min; after-race mean, 54 beats/min), and an increase in interventricular septal diastolic thickness (base-line mean, 28 mm; after-race mean, 33 mm). The septal thickening fraction (base-line mean, 59%; after-race mean, 38%), the left atrioventricular valve E to F slope (base-line mean, 224 mm/s; after-race mean, 175 mm/s), the left ventricular diastolic dimension (base-line mean, 99 mm; after-race mean, 86 mm), the fractional shortening of the left ventricle (base-line mean, 41%; after-race mean, 37%), the aortic root dimension (base-line mean, 63 mm; after-race mean, 58 mm), the caudal aortic wall excursion (base-line mean, 19 mm; after-race mean, 11 mm) and the left atrial diastolic dimension (base-line mean, 46 mm; after-race mean, 39 mm), decreased significantly (P < 0.05). In base-line echocardiographs, late diastolic left atrioventricular valve motion was evident in 9 horses. The aberrant left atrioventricular valve motion was not evident in after-race echocardiographs. Seemingly, central vascular volume decreased in these horses during the recovery phase of severe strenuous endurance competition.
Biochemical and genetic characterization of Corynebacterium pseudotuberculosis
Authors: Songer J. Glenn , Beckenbach Karen , Marshall Marilyn M. , Olson George B. , Kelley Lee
Published: February 2025

Isolates (n = 94) of Corynebacterium pseudotuberculosis were obtained from sheep, goats, horses, and cattle from various parts of the world. The isolates were characterized biochemically and by restriction endonuclease analysis of dna. We found near homogeneity in the ability of isolates to ferment carbohydrates and to produce urease. All isolates produced phospholipase D and catalase. The ability of isolates from horses to reduce nitrate, the inability of isolates from sheep and goats to do so, and the correlation of this characteristic with results of restriction endonuclease analyses confirmed the existence of 2 biovars of C pseudotuberculosis. We propose that these biovars be referred to as biovar equi for isolates that reduce nitrate and biovar ovis for isolates that fail to do so.
Quantitative buffy coat analysis for hematologic measurements of canine, feline, and equine blood samples and for detection of microfilaremia in dogs
Authors: Brown Scott A. , Barsanti Jeanne A.
Published: February 2025

A quantitative buffy coat (qbc) analysis was evaluated for 175 canine, 125 feline, and 125 equine blood samples. The method used centrifuged whole blood and yielded rapid results expressed as respective band lengths for rbc, granulocytes, nongranulocytes, and platelets. Simple regression analysis of band lengths and reference laboratory methods yielded correlation coefficients (r) ranging from 0.72 to 0.99. The pcv, granulocyte count, and total wbc count, as determined by the 2 methods, correlated well (r ≥ 0.93 in all cases). Platelet and nongranulocyte counts were less well correlated. The qbc system provided a means of performing rapid hematologic screening. The principal problem encountered was poor separation of the rbc-granulocyte interface in 17% of canine samples, which interfered with measurement of band lengths. Evaluation of the qbc tube for detection of Dirofilaria immitis microfilaremia revealed 100% sensitivity to counts as low as 160 microfilariae/ml of whole blood.
Effect of reduced growth rate on the prevalence and severity of osteochondrosis in gilts
Authors: Carlson C. S. , Hilley H. D. , Meuten D. J. , Hagan J. M. , Moser R. L.
Published: February 2025

Ninety-six recently weaned gilts were assigned to 3 groups. Group-1 gilts were fed a corn-soybean meal diet ad libitum and were killed when they weighed 110 kg. Gilts in groups 2 and 3 were fed 70% of the feed consumed by group-1 gilts. Group-2 gilts were killed when they weighed 110 kg, and group-3 gilts were killed at the same age as group-1 gilts.

At slaughter, the right pelvic and thoracic limbs from all gilts were removed, and the distal end of each femur and humerus was sectioned serially at 5-mm intervals. Articular-epiphyseal cartilage complexes from these sites were examined grossly, radiographically, and histologically. Effects of treatment (ad libitum vs limited energy intake) and average daily gain on the prevalence and severity of lesions were analyzed statistically, using χ2 analysis, a categoric-modeling technique, analysis of variance, and correlation coefficients.

Of humeri and femora, 49 and 70%, respectively, had lesions of osteochondrosis, and 86% of the gilts had a lesion at one or both sites. Group-2 gilts (killed at 110 kg, but approx 70 days older than group-1 gilts) had significantly lower prevalence (P = 0.009) and severity (P = 0.002) of osteochondrosis of the distal end of the femur than did gilts in groups 1 and 3. When each group was evaluated individually, gilts that had a higher average daily gain had an increased prevalence and severity of lesions.
Function of phagocytes obtained from lacteal secretions of lactating and nonlactating cows
Authors: Fox Lawrence K. , McDonald John S. , Hillers Joe K. , Corbeil Lynette B.
Published: February 2025

Phagocytes, macrophages and neutrophils, were obtained from lacteal secretions of lactating (n = 13) and nonlactating cows (n = 14). Secretions from nonlactating cows were collected at 7 and 14 days after cessation of lactation. Phagocytes were incubated in vitro with Staphylococcus aureus or Escherichia coli, and function was assessed by fluorescent microscopy of cell suspensions stained with acridine orange and crystal violet. A greater percentage of macrophages from nonlactating cow secretions collected on day 14 phagocytized bacteria than did those collected on day 7. A greater percentage of macrophages from nonlactating cow secretions collected on days 7 and 14 phagocytized bacteria than did neutrophils obtained from the same secretions. A similar percentage of phagocytes from nonlactating cow secretions phagocytized bacteria, compared with phagocytes from lactating cow secretions. Results indicated that the intramammary macrophage may be most important in defense of the mammary gland during the early nonlactating period, because it was more phagocytic than the neutrophil and was more active at 14 days than at 7 days into the nonlactating period.
Covalently protein-bound bilirubin conjugates in cholestatic disease of dogs
Authors: Rothuizen Jan , Ingh Ted van den
Published: February 2025

We investigated the occurrence of covalently protein-bound bilirubins in the plasma of dogs with hyperbilirubinemia attributable to hepatobiliary diseases or Coombs test-positive hemolysis. The bilirubins in plasma were measured with the conventional Van den Bergh reaction, by treatment with diazotized p-iodoaniline, and by high-performance liquid chromatography of bilirubin and its methylesters after alkaline methanolysis.

All but one dog had covalently protein-bound bilirubin conjugates. The concentration and the fraction of total bilirubins varied in all diseases investigated, but they tended to be low in primary hemolysis. The “biliprotein” complex accounted for 2 to 94% of total plasma bilirubins. Because biliprotein usually is not cleared by the liver, but has a half-life comparable with that of albumin, it prevents the evaluation of the actual state of the underlying disease. Measurement of the total bilirubin concentration exclusively with the Van den Bergh reaction, therefore, is clinically useless. Other methods should be introduced for routine bilirubin assays, permitting the measurement of noncovalently bound pigment as a meaningful estimate of the course of the disease.
Effect of an interfering substance on determination of potassium by ion-specific potentiometry in animal urine
Authors: Brooks Charles L. , Garry Franklyn , Swartout Margaret S.
Published: February 2025

Analytical characteristics of photometry and ion-specific potentiometry for urine from sheep, horses, cows, dogs, and cats were determined, using solutions of sodium and potassium chloride. The performance of both methods were acceptable, but the ion-specific potentiometer (in the mode for urine analysis) was superior in terms of linearity of response and correlation between actual vs measured concentrations. Coefficients of variation of either method for repeated analyses of various concentrations of sodium and potassium were always < 2.5%.

The measurement of sodium concentration in urine samples correlated well between both methods for samples from sheep, horses, cows, dogs, and cats. In contrast, measurement of potassium concentrations in urine samples from sheep, horses, cows, and cats was underestimated consistently by ion-specific potentiometry. The magnitude of the apparent error was variable between species and was often increased with greater urine potassium concentrations. These phenomena were not seen in urine samples from dogs. Sequential dilution of urine samples from sheep before analysis reduced the magnitude of the error observed by ion-specific potentiometry. Seemingly, an equilibrium process existed in which potassium was bound by an anionic or zwitterionic chemical and was sequestered from interaction with the ion-specific electrode. Ultrafiltration experiments indicated the putative potassium chelator was a low molecular weight compound.
Effect of stocking rate, grazing system, and fenbendazole treatment on subclinical parasitism in dairy heifers
Authors: Kunkel J. R. , Murphy William M.
Published: February 2025

Average daily weight and fecal parasitic egg count were compared among sixty 7- to 15-month-old Holstein heifers randomly assigned to 8 groups. The following variables were examined: grazing system (continuous vs rotational), stocking rate (3.5 vs 5 heifers/ha), and treatment [control vs dosing with a 10% suspension of fenbendazole (5 mg/kg of body weight) given orally 21 and 49 days after heifers were placed on pasture]. Two heifers from each group were euthanatized 4 weeks after the completion of the 148-day trial to determine the number of parasitic larvae and adults in the abomasum and intestine.

Heifers treated with fenbendazole had significantly (P < 0.001) fewer fecal ova and fewer inhibited abomasal larvae (P < 0.05) than did controls. Mean total weight gain and mean daily rate of gain of fenbendazole-dosed heifers were significantly (P < 0.01) increased by 17.3 kg or 0.12 kg/day, respectively, compared with those of nontreated heifers. Seemingly, stocking rate and grazing systems had no marked effect on subclinical parasitism in heifers.
Anatomic and radiologic observations of the clavicle of adult dogs
Authors: McCarthy P. H. , Wood A. K. W.
Published: February 2025

In an anatomic and radiologic study of the clavicle of 50 adult dogs of 10 breeds, the clavicle had ossified in 96% of the dogs. The clavicles studied had various shapes, and each clavicle was attached to the caudomedial part of the clavicular intersection of the brachiocephalic muscle, to the mastoid part of the cleidocephalic muscle, and to 4 radiating bands of connective tissue fasciculi. One band was attached to the caudal border of the scapula and fascia deep to the latissimus dorsi muscle, 1 was attached to the manubrium of the sternum, and 1 each was attached to the epimysia of the superficial pectoral and sternocephalic muscles. We concluded that, during movements of the thoracic limb, the clavicle and the 4 fasciculated connective tissue bands associated with it stabilize the position of the brachiocephalic muscle with relation to the crest of the greater tubercle of the humerus. Also, the fasciculated band attached to the caudal border of the scapula provides protection for nerves from the brachial plexus and axillary blood vessels that supply the thoracic limb.
Preliminary studies of the development of Anaplasma marginale in salivary glands of adult, feeding Dermacentor andersoni ticks
Authors: Kocan Katherine M. , Wickwire Kathie B. , Ewing S. A. , Hair Jakie A. , Barron Selwyn J.
Published: February 2025

On each day of feeding on susceptible calves, salivary glands obtained from groups of adult ticks that transmitted Anaplasma marginale were examined for A marginale colonies by use of light microscopy and transmission electron microscopy. On day 8 of feeding, salivary glands were examined, using fluorescein-labeled antibody and methyl green-pyronine stain. Use of fluorescein-labeled antibody consistently revealed small numbers of fluorescent foci in salivary gland acinar cells obtained from ticks that had fed for 8 days. Colonies of A marginale were seen by transmission electron microscopy only in salivary gland acini of male ticks; these colonies could not be identified, using light microscopy, in companion 1-μm plastic sections stained with Mallory stain. Methyl green-pyronine stain, used commonly to detect theilerial parasites in tick salivary glands, did not differentiate A marginale from cytoplasmic inclusions normally found in salivary gland acinar cells.
Plasma fibronectin concentration associated with various types of canine neoplasia
Authors: Feldman Bernard F. , Brummerstedt Erik , Larsen Liselotte Stein , Larsen Steen
Published: February 2025

Fibronectin, a large glycoprotein found in soluble form in plasma and in insoluble form in connective tissue matrices, has been implicated in cell-to-cell and cell-to-substratum interactions, inflammation and tissue repair, phagocytosis, hemostasis, and oncogenic cell transformation. Because fibronectin concentration is diminished or lacking on cell surfaces of many transformed cell lines and because decreased concentration of plasma fibronectin is associated with suboptimal mononuclear phagocyte system function and host defense, plasma fibronectin concentration was evaluated in 119 dogs with various forms of neoplasia. Included were 43 dogs with neoplasia of the skin and soft tissue, 18 with gastrointestinal tract neoplasia, 29 with mammary gland neoplasia, and 29 with various other types of neoplasia. Of the dogs studied, 44 (37%) had evidence of metastatic disease. This group had fibronectin concentration that differed significantly (P < 0.01) from the plasma fibronectin concentration reference interval. Within this group, 9 dogs (20% of this group) had plasma fibronectin values within the reference interval, 33 (75%) had significantly (P < 0.01) lower values than the reference interval, and 2 (5%) had significantly (P < 0.01) higher values than the reference interval. These data suggested that fibronectin concentration determination, when results are abnormal, may be of diagnostic and prognostic interest.
Effect of equine ehrlichial colitis on the hemostatic system in ponies
Authors: Morris Debra Deem , Messick Joann , Whitlock Robert H. , Palmer Jon , Ward Michael V. , Feldman Bernard F.
Published: February 2025

Hemostatic function was determined in 10 ponies at various times after inoculation with Ehrlichia risticii to determine whether equine ehrlichial colitis (eec) caused changes in the hemostatic system and to determine the prognostic value of hemostatic function tests during eec. Mean platelet count; plasma fibrinogen, fibronectin, factor VIII:coagulant, α2-antiplasmin, and plasminogen values; and serum concentrations of fibrin/fibrinogen degradation products changed significantly (P < 0.05) from base line (day 0, before inoculation) during 18 days after inoculation with E risticii. Four ponies that died or were euthanatized because of severe clinical signs of eec had significantly (P < 0.05) greater mean plasma fibrinogen concentrations plasma factor VIII:coagulant values, and activated partial thromboplastin times immediately before death than did the 6 surviving ponies. Factor V concentrations were significantly (P < 0.05) lower on postinoculation days 10 and 20 in nonsurvivors. Seemingly, changes in hemostasis took place during eec. Ponies that did not survive eec had greater laboratory evidence of coagulopathy.
Postweaning diarrhea in swine: Experimental model of enterotoxigenic Escherichia coli infection
Authors: Sarmiento Juan I. , Casey Thomas A. , Moon Harley W.
Published: February 2025

A reproducible model of postweaning colibacillosis was obtained by controlling management and environmental variables to simulate conditions often seen at weaning. Suckling pigs were exposed briefly to starter diet at 1 week of age, weaned at 3 weeks of age, held at an ambient temperature of 20 ± 2 C, and again given the starter diet. One day after weaning, each pig was given 1010 colony-forming units of enterotoxigenic Escherichia coli strain M1823B (0157:K88ac:H43-LT+ STb+) in broth containing 1.2% sodium bicarbonate via stomach tube. In vitro adhesion by strain M1823B to isolated intestinal branch borders was used to test pigs for susceptibility to K88. In this model, 3 syndromes were induced in susceptible pigs: (1) peracute fatal diarrhea; (2) moderate diarrhea, weight loss, and fecal shedding of the inoculum strain; and (3) no diarrhea, weight loss, and fecal shedding of the inoculum strain. Rotavirus particles were not found in fecal specimens of pigs with diarrhea. The K88-susceptible, noninoculated control pigs remained clinically normal. It was concluded that susceptibility to adhesion by K88+ enterotoxigenic Escherichia coli was a requirement for the production of disease in this model; inoculation with rotavirus was not necessary.
Verification of ineffectual activity of ivermectin against adult Onchocerca spp in the ligamentum nuchae of horses
Authors: Lyons E. T. , Drudge J. H. , Tolliver S. C.
Published: February 2025

Ivermectin paste formulation (200 μg/kg) was administered orally to 27 horses (13 Thoroughbreds and 14 of mixed breeding) to evaluate activity against adult Onchocerca spp in the ligamentum nuchae. Ages, known or estimated, of the horses ranged from 1 to 22 years. Single or multiple doses (1 to 5) of the drug were given to each horse. When multiple doses were administered, the intervals between treatments ranged from 7 to 92 days. At 27 to 171 days after initial treatment (single dose or first of multiple doses), the horses were killed. Some of the horses treated more than once were killed as soon as 7 days after the last treatment.

At necropsy, Onchocerca spp were found in the ligamentum nuchae of 24 (89%) of the 27 horses. All of the specimens were pieces of worms, apparently adult, which appeared to be alive. The only noninfected horses were 2 to 3 years old. In 18 (75%) of the 24 infected horses, microfilariae, most being obviously viable, were found in the worm specimens or ligamentum nuchae.
Prevalence and specificity of antibodies to bovine respiratory syncytial virus in sera from feedlot and range cattle
Authors: Collins James K. , Teegarden Robert M. , MacVean Duncan W. , Smith George H. , Frank Glenn R. , Salman
Published: February 2025

The specificity of serum antibodies for the polypeptides of bovine respiratory syncytial virus (brsv) was examined, using sera obtained from feedlot and range cattle. Test results in sera from feedlot cattle indicated a 60% rate of seroconversion and 95% seropositivity to brsv, associated with lack of clinical signs indicative of respiratory tract disease. Exposure to other common respiratory tract viruses also was high (≥ 92% to bovine herpesvirus type 1, bovine viral diarrhea virus, and parainfluenza virus type 3). Test results in sera from range cattle indicated brsv seropositive rates of 28% in calves, 49% in yearling cattle, and 70% in mature cows; clinical signs of respiratory tract disease were not observed in these cattle. Antibodies to brsv in sera from cattle in both environments reacted predominantly with polypeptides of molecular weight 80,000 through 85,000, 40,000, and 28,000. Reactivity to a glycoprotein of molecular weight between 43,000 and 44,000 and to several glycopolypeptides of smaller molecular weight increased in serum specimens obtained from feedlot cattle between time of entry into the feedlot and slaughter.
Inhibition of feline infectious peritonitis virus replication by recombinant human leukocyte (α) interferon and feline fibroblastic (β) interferon
Authors: Weiss Richard C. , Toivio-Kinnucan Maria
Published: February 2025

Replication of feline infectious peritonitis virus (fipv) in feline cell cultures was inhibited after incubation of cells with either human recombinant leukocyte (α) interferon (ifn) or feline fibroblastic (β) ifn for 18 to 24 hours before viral challenge exposure. Compared with virus control cultures, fipv yields were reduced by ranges of 0.1 to 2.7 log10 or 2 to 5.2 log10 tcid50 in cultures treated with human α- or feline β-ifn, respectively; yield reductions were ifn dose dependent. Sensitivity to the antiviral activities of ifn varied with cell type; feline embryo cells had greater fipv yield reductions than did similarly treated feline kidney or feline lung cells. Comparison of the virus growth curves in ifn-treated and virus control cultures indicated marked reduction in intracellular and extracellular fipv in ifn-treated cultures. Compared with virus control cultures, intracellular and extracellular infectivity in ifn-treated cultures was delayed in onset by 12 and 30 hours, respectively, and fipv titers subsequently were reduced by 3 to 3.5 and 5 log10 tcid50, respectively. Frequently, immunofluorescent and electron microscopy of ifn-treated cells or cell culture fluids did not reveal virus; however, even in cultures without viral cytopathic changes, small amounts of virus occasionally persisted in cells.
Kinetics and kinematics of the equine hind limb: In vivo tendon loads and force plate measurements in ponies
Authors: Riemersma Dirk J. , Schamhardt Henk C. , Hartman Wrister , Lammertink Jos L. M. A.
Published: February 2025

Loads on the suspensory ligament, deep digital flexor tendon, superficial digital flexor tendon, and long digital extensor tendon of the equine hind limb were determined in ponies by use of implanted strain gauges consisting of silicone rubber tubes filled with mercury. Recordings were made simultaneously with force plate measurements and high-speed film recordings while the ponies were walking. The relationship between strain gauge signals and tendon loads was obtained from tension-strain tests performed after death of the ponies. The suspensory ligament and the 2 digital flexor tendons were loaded during the stance phase, and the extensor tendon was loaded mainly during the swing phase. The loading pattern of the suspensory ligament, with peak loads of 4.6 N/kg of body weight, correlated well with the vertical component of the ground reaction force. Maximal loading of the deep digital flexor tendon was observed during the second half of the stance phase, with peak values of 6.7 N/kg. The superficial digital flexor tendon was loaded maximally at the beginning of the stance phase, with a peak load of 4.1 N/kg, and the long digital extensor tendon was loaded maximally during the swing phase, with a peak load of 0.3 N/kg.

Recordings made from this procedure for calibration of the strain gauge signals to tendon load and tendon strain, in combination with the force plate measurements, enabled verification of the results by torque analysis of the lower portion of the hind limb, using the vector of the ground reaction force, limb conformation, and limb geometric configuration. Torque analysis of the lower extremity indicated that the determined tendon loads were in agreement with the recorded ground reaction forces.
Studies on the pathogenesis and interspecies transmission of respiratory syncytial virus isolated from sheep
Authors: Bryson David G. , Evermann James F. , Liggitt H. Denny , Foreyt William J. , Breeze Roger G.
Published: February 2025

Inoculation of lambs with an ovine isolate of respiratory syncytial virus (rsv) by a combined intranasal and intratracheal route resulted in mild respiratory tract illness, with respiratory tract lesions. Lung lesions were characterized by bronchitis and bronchiolitis, hyperplasia of bronchial and bronchiolar epithelium, peribronchiolar and perivascular accumulations of lymphocytes, alveolar septal thickening, and collapse. Respiratory syncytial virus was recovered from the respiratory tract of inoculated lambs, and rsv antigen was demonstrated by immuno-peroxidase staining of bronchiolar and alveolar epithelial cells in pneumonic lesions of lambs euthanatized on post-inoculation days 5 and 6. Other primary respiratory tract pathogens were not isolated. Clinical signs of respiratory tract illness or respiratory tract lesions did not develop in the in-contact control lamb.

Inoculation of the ovine rsv isolate into calves and deer fawns resulted in infection in both species, and at necropsy, pneumonic lesions were present. A mild to moderate respiratory tract illness developed in the calves, but clinical disease was not seen in the fawns. Lung lesions in fawns were similar to those seen in lambs; lesions in calves were characterized by collapse, scattered areas of parenchymal necrosis, and bronchiolitis. Respiratory syncytial virus was reisolated from the lower respiratory tract of inoculated calves and fawns, and immunoperoxidase-positive epithelial cells were seen in pneumonic lesions. Other primary respiratory pathogens were not detected. Respiratory syncytial virus infection was not demonstrable in control animals that were in contact with inoculated animals.

We concluded that an ovine rsv isolate, when inoculated in a severe challenge regime, caused mild primary pneumonia in lambs and lesions similar to those described in epizootics of naturally occurring ovine respiratory tract disease. Also, the ovine rsv caused lower respiratory tract lesions in infected calves and deer.
Effect of respiratory infections caused by bovine herpesvirus-1 or parainfluenza-3 virus on bovine alveolar macrophage functions
Authors: Brown Talmage T. , Ananaba Godwin
Published: February 2025

Calves, 90 to 130 days old, were inoculated with bovine herpesvirus-1 (bhv-1) or parainfluenza-3 (pi-3) virus. Pulmonary lavage specimens obtained from calves before virus inoculation contained 98% alveolar macrophages (am) and 1% neutrophils. Six days after inoculation, the mean percentage of neutrophils in lavage specimens had significantly increased to 7.9 ± 6.0% in bhv-1-inoculated calves and to 18.3 ± 9.9% in pi-3 virus-inoculated calves, reflecting viral-induced pulmonary inflammation that was confirmed histologically. Approximately 75% of am obtained before virus inoculation had Fc surface receptors, and 60% had C3b receptors. Six days after inoculation, the percentage of am with Fc and C3b receptors was significantly reduced to 69.7 ± 8.6% and 27.1 ± 19.8%, respectively, in bhv-1-inoculated calves and to 67.8 ± 15.4% and 38.8 ± 23.2%, respectively, in pi-3 virus-inoculated calves. Alveolar macrophages obtained after virus inoculation were significantly impaired in their ability to phagocytize opsonized Staphylococcus epidermidis, but were able to kill ingested bacteria. Alveolar macrophage dysfunctions caused by bhv-1 or pi-3 respiratory infection did not differ appreciably.
Identification of viral antigens that induce antibody responses on exposure to coronaviruses
Authors: Ingersoll Jerald D. , Wylie Dwane E.
Published: February 2025

Various techniques were used to look for protective, non-cross-reactive antibodies in the sera of cats exposed to virulent feline infectious peritonitis virus (fipv). Antibodies reactive with feline enteric coronavirus (fecv) from fipv-exposed cats were adsorbed by several passages over an fecv-Sepharose column. In an elisa against fecv and fipv, the activity against both viruses was removed at the same rate; thus, no fipv-specific antibodies could be identified. By gel electrophoresis-derived elisa, the responses of cats surviving fipv exposure were compared with those of cats succumbing to fipv exposure to determine whether survival could be correlated with an antibody response against a particular virus protein. Results indicated that both groups responded in the same way to the matrix envelope protein and nucleocapsid proteins. Even though the response to peplomer in each group was weak, the survivor group responded better to this protein. Furthermore, the response of this group to the peplomer protein had the highest correlation with virus neutralization titer.
Comparison of serologic assays for measurement of antibody response to coronavirus in cats
Authors: Ingersoll Jerald D. , Wylie Dwane E.
Published: February 2025

Serologic virus neutralization tests, indirect immunofluorescence tests, and elisa, using tissue culture-adapted feline infectious peritonitis virus (fipv) or feline enteric coronavirus (fecv) were compared for their ability to distinguish specific virus exposure in cats. Sera of specific-pathogen-free cats inoculated with virulent or modified fipv or fecv were used to compare the sensitivity and specificity of the homologous assays to a heterologous assay that measures antibody reactivity with transmissible gastroenteritis virus of swine. The geometric means of the serologic titers in fipv and fecv assays were higher for fipv- or fecv-infected specific-pathogen-free cats than the geometric means of the transmissible gastroenteritis virus assays for most groups. None of the assays was specific enough to discern the virus to which a cat had been exposed. However, the fipv virus neutralization test appeared to be more sensitive for detection of an early response to fipv infection than did the fipv immunofluorescence test or fipv-elisa.
Adherence of streptococcal isolates from cattle and horses to their respective host epithelial cells
Authors: Valentin-Weigand Peter , Chhatwal Gursharan S. , Blobel Hans
Published: February 2025

Adherence of Streptococcus dysgalactiae isolates from cattle and S equi isolates from horses to their respective host epithelial cells was compared with the adherence of S pyogenes to human epithelial cells. The adherence was quantitatively determined by use of fluorescein-labeled streptococci. All 3 streptococcal species adhered selectively to their respective host cells. The mechanism of adherence was evaluated by binding studies with adhesive plasma protein, fibronectin. Although all 3 streptococcal species bound fibronectin, S dysgalactiae and S equi interacted preferentially with a 210-kilodalton (kD) C-terminal fragment of fibronectin, whereas S pyogenes bound only a 29-kD N-terminal fragment. A synthetic peptide Gly-Arg-Gly-Asp-Ser, representing the host cell attachment site of fibronectin, partially inhibited the binding of fibronectin and of its 210 kD fragment to S dysgalactiae, but not to S equi. The binding of fibronectin and its 29-kD fragment to S pyogenes was not inhibited by Gly-Arg-Gly-Asp-Ser. These differences in binding activities corresponded to the ability of fibronectin to mediate the adherence of the streptococci to the epithelial cells: fibronectin strongly inhibited the adherence of S pyogenes and S equi to the epithelial cells, but only weakly inhibited that of S dysgalactiae.
Atherosclerosis in coronary, aortic, and sciatic arteries from wild male turkeys (Meleagris gallopavo silvestris)
Authors: Krista L. M. , McQuire J. A.
Published: February 2025

Heart, aorta, and sciatic arteries were collected from 157 wild male turkeys (Meleagris gallopavo silvestris) by hunters in 9 states during the spring 1983 and 1984 hunting seasons. In descending order of extent and severity, intimal vascular changes were observed in the left sciatic artery, aorta at the celiac region, cranial abdominal portion of the aorta, sciatic bifurcation, caudal abdominal portion of the aorta, coronary arteries, and thoracic portion of the aorta. Only the aorta from the celiac region and right sciatic artery had significant differences (P < 0.05) among turkeys from various locations. Turkeys from Indiana had significantly (P < 0.05) larger plaque scores in the celiac region than did those from Alabama, Missouri, and South Carolina. Turkeys from Indiana also had significantly (P < 0.05) greater plaque scores in the right sciatic artery than did turkeys from Arkansas. When all tissues were considered, tissues from turkeys from Michigan had the highest plaque scores and those from Iowa had the lowest. Plaque scores for turkeys from Michigan were significantly (P < 0.05) higher overall (including all blood vessels) than were plaque scores for turkeys from Alabama, Arkansas, Iowa, and South Carolina.

Few significant (P < 0.05) correlations were detected among plaque scores in turkeys from within states of origin (geographic location). Also, only a few significant (P < 0.05) correlations were determined between age or body weight and atherosclerosis for blood vessels from turkeys within various states.
Capillary permeability to endogenous macromolecules in the equine digit
Authors: Allen Douglas , Korthuis Ronald J. , Clark E. Susan
Published: February 2025

Microvascular permeability characteristics were evaluated in digits of 7 adult horses. After capillaries were isolated and an extracorporeal perfusion circuit for the digit was established, a lymphatic vessel draining the distal portion of the phalangeal region was cannulated at the level of the coronary band. Venous pressure was increased in a stepwise manner, and lymph flow, lymph protein concentration (Cl), and plasma protein concentration (Cp) were determined after measured variables were allowed to reach steady state. Lymph-to-plasma protein concentration ratios (Cl/Cp) and lymph and plasma oncotic pressures were determined from samples collected during steady state. The osmotic reflection coefficient was determined after Cl/Cp became constant, regardless of increasing lymph flow, and was expressed as 1 — Cl/Cp. The osmotic reflection coefficient for the digit was 0.67. Seemingly, the microvasculature bed of the digit was relatively permeable and could maintain only 67% of the endogenous macromolecules within the vasculature.
Stimulated esophageal groove closure in adult goats
Authors: Mikhail Michel , Brugère Henri , Le Bars Henri , Colvin Harry W.
Published: February 2025

In healthy adult goats, closure of the esophageal groove was induced by thirst, iv administered vasopressin, and intracarotid administration of hypertonic NaCl solutions. The efficiency of stimulation was tested directly by visual inspection of the course taken by orally administered solutions through a ruminal or abomasal fistula, palpation of the lips of the esophageal groove through a ruminal fistula, and indirectly by following the glucose dynamics in the blood after oral administration of glucose solution.

Esophageal groove closure was observed during drinking after a 48-hour period of water deprivation. Intracarotid administration of 1.5 ml of a saturated solution or 10.5 ml of a 1.5% solution of NaCl also stimulated groove closure; however, groove closure stimulated by administration of vasopressin is the most satisfactory procedure for passing compounds of therapeutic importance directly from the cardiac orifice to the abomasum.
Bacterial population and histologic changes in dogs with perianal fistula
Authors: Killingsworth C. R. , Walshaw Richard , Dunstan R. W. , Rosser E. J.
Published: February 2025

Ages of 44 dogs with perianal fistula, ranged from 6 months to 13 years (mean, 5.2 years). German Shepherd Dogs and Irish Setters were statistically (P < 0.01) over-represented compared with those breeds in a canine hospital population (n = 22,047) for the same period. There was a 2:1 male-to-female ratio, with 38 (86.4%) of dogs sexually intact and 6 (13.6%) of dogs neutered. Eleven types of bacterial organisms were recovered from deep perianal tissues of which Escherichia coli, Staphylococcus aureus, (β-hemolytic streptococci, and Proteus mirabilus were most common. Organisms were not recovered from 7 dogs. Of 93 isolates, 88.3% were susceptible to gentamicin, 80.5% to cephalothin, 79.2% to chloramphenicol, and 74% to trimethoprim-sulfamethoxazole.

Fifty-one biopsy specimens from 44 dogs were classified as having early, intermediate-, and late-stage lesions based on the amount of fibrosis, severity of the inflammatory response, and, if present, depth of sinus tracts. In most biopsy specimens, all 3 stages were represented in the same histologic section. In 45 specimens, most inflamed lesions were in the dermis of the zona cutanea. Hidradenitis was present in 22 biopsy specimens and was associated with the formation of epithelial-lined sinus tracts.
Topically applied cyclosporin for modulation of induced immunogenic uveitis in rabbits
Authors: Kaswan Renee L. , Kaplan Henry J. , Martin Charles L.
Published: February 2025

The experimental model of immunogenic uveitis induced by intraocular injection of human serum albumin in rabbits was inhibited by the topical application of cyclosporin A. The acute nonspecific inflammatory response that immediately follows intravitreous injection was not affected. However, the severe panuveitis that develops during the second week was markedly reduced. The safety and efficacy of topically applied cyclosporin A in this model of uveitis suggests that topical administration of this antigen-nonspecific immunosuppressor may be an effective route of therapy for certain immune-mediated forms of uveitis.
Histopathologic effects of dimethyl sulfoxide on equine endometrium
Authors: Frazer Grant S. , Rossol Thomas J. , Threlfall W. R. , Weisbrode S. E.
Published: February 2025

Endometrial fibrosis is a major cause of infertility in broodmares. Because of the proven anti-inflammatory effects of dimethyl sulfoxide (dmso) and its influence on collagen, the effect of dmso on the endometrium was investigated in mares. Solutions of dmso (25%, 50%, or 75%) were infused into the uterus of clinically normal mares. Examination of serially obtained biopsy specimens revealed epithelial ulceration and stromal inflammation that were proportional to the dmso concentration infused, but vasodilatation was not observed. In all mares, the endometrium had returned to normal by day 21 after dmso infusion.
Characterization and purification of the F17 adhesin on the surface of bovine enteropathogenic and septicemic Escherichia coli
Authors: Lintermans Paul F. , Pohl Pierre , Bertels Anne , Charlier Gerard , Vandekerckhove Joel , Van Damme Jozef , Schoup Johan , Schlicker Christine , Korhonen Timo , De Greve Henri , Van Montagu Marc
Published: February 2025

The F17 antigen from bovine enterotoxigenic Escherichia coli strain (E coli 25KH09), which adhered to calf intestinal villi, was isolated. An enterotoxin-negative derivative (25KH09st) was used for further studies. Using an immunogold-labeling technique, the F17 antigen was characterized as a fimbrial protein. Pure fimbriae with a subunit molecular weight of 20,000 were obtained by homogenization and use of a sucrose gradient. The adhesion of E coli 25KH09st was mediated by the F17 fimbriae, as both F17 antibodies and F17 protein blocked the adhesion of the strain 25KH09st. The F17 fimbriae were serologically distinct from K88, K99, F41, and 987P fimbriae and did not agglutinate bovine, ovine, guinea pig, human, or chicken erythrocytes. Peptide fingerprint analysis revealed F17 and F(Y) adhesins to be homologous, if not identical.
Failure to demonstrate transmission of enzootic bovine leukemia virus infection from cows to sheep by use of common injection needles
Authors: Weber A. F. , Meiske J. C. , Haggard D. L. , Sorensen D. K. , Domagala A. M. , Flaum A. M.
Published: February 2025

Four bovine leukemia virus (blv)-seropositive and 2 blv-seronegative cows were used as donors in a study to provide evidence whether im injection with common needles is a means of spreading bovine leukemia. Sheep were used as recipients. Of the 4 blv-seropositive cows, 2 had high virus expression (ve; 43% and 28% of their lymphocyte thin sections had associated blv-particles), whereas the other 2 cows did not have observed ve. After each of the 4 cows was given an injection of a 5-antigen Leptospira bacterin, a blv-seronegative sheep was immediately given an injection of the same bacterin with the same needle. None of these sheep seroconverted, nor did either of 2 sheep given only the bacterin (with a previously unused needle). Sheep inoculated iv with 0.2 ml of whole blood from both of the cows with high ve and from 1 of the 2 blv-seropositive cows that did not have observed ve did seroconvert. In contrast, the sheep inoculated with 0.2 ml of blood from the remaining blv-seropositive (0% ve) cow and from the 2 blv-seronegative cows remained seronegative. These results were interpreted to indicate that the quantity of infective lymphocytes passed during injection with common needles is too small to induce infection.