bluuebunny/crossref_metadata_2025 huggingface dataset:
Morphogenesis of canary poxvirus and its entrance into inclusion bodies
Authors: Sadasiv Eileen C. , Chang Pei W. , Gulka Gary
Published: February 2025

A virus isolated from a natural outbreak of canarypox was replicated on the chorioallantoic membranes of chicken embryos, and its ultrastructure and development were observed. Electron microscopy of thin sections of pocks produced on the chorioallantoic membranes revealed a variety of developmental forms which appear similar to those demonstrated in studies of vaccinia, ie, viroplasm or viral factories; immature, undifferentiated virions partially enclosed by membranes; completely enclosed nondifferentiated spherical or oval virions; immature virions with discrete nucleoids; and the more compact brick-shaped mature virions. Two types of A-type inclusions were noted: those with virions around the periphery, and those filled with virus particles. The appearance of mature viruses within the inclusion bodies and different stages of viruses outside the inclusion indicate that in a course of development, maturing poxvirus may enter the inclusion bodies as they acquire surface tubules on their envelopes. Mature virions also were seen budding out of the cell membrane, apparently enveloped in a portion of the membrane.

Studies showing the entrance of poxvirus into inclusion bodies have not been reported. In this report, electron micrographs are shown of viruses entering inclusion bodies.
Experimental bovine respiratory syncytial virus infection in conventional calves: Ultrastructural respiratory lesions
Authors: Castleman W. L. , Chandler S. K. , Slauson D. O.
Published: February 2025

The morphogenesis and repair of airway and alveolar injury induced by bovine respiratory syncytial virus (brsv) was studied ultrastructurally in conventional calves to characterize pulmonary cell types susceptible to viral infection and cytopathologic changes associated with infection. Viral nucleocapsids and budding virions were present in tracheal and bronchial ciliated and nonciliated epithelial cells and mucous cells 3, 5, and 7 days after inoculation and in bronchiolar ciliated and nonciliated epithelial cells 5 days after inoculation. Mild interstitial pneumonia was observed 5 days after inoculation and was characterized by swelling of type 1 and type 2 alveolar epithelial cells, interstitial edema, and infiltration by lymphocytes and macrophages. Viral assembly and release in tracheal and bronchial epithelial cells was associated with loss of cilia from ciliated cells, formation of syncytial epithelial cells, swelling of mitochondria and endoplasmic reticulum, and cell necrosis. Neutrophils, lymphocytes, and macrophages were present in close association with the viral-infected and damaged epithelial cells. There was intercurrent hyperplasia of basal epithelial cells that, in association with other epithelial lesions, resulted in the loss of normal ciliated epithelium in these airways 5 and 7 days after inoculation. Regeneration of airway epithelium was largely completed by 10 days after inoculation, except in 1 of 4 calves that had failure of epithelial repair and that developed secondary bacterial pneumonia. Pulmonary ultrastructure in brsv-inoculated calves 30 days after inoculation was indistinguishable from that in controls. The results demonstrated that brsv can induce reversible alterations in airway epithelium, which may cause depression of mucociliary clearance and thereby enhance susceptibility to bacterial infection.
Toxicity of Riddell's groundsel (Senecio riddellii) to cattle
Authors: Johnson A. Earl , Molyneux Russell J. , Stuart L. D.
Published: February 2025

The toxicity of Riddell's groundsel (Senecio riddellii) fed to calves in gelatin capsules, by gavage, or mixed in their hay ration was determined. Dosages were varied according to the pyrrolizidine alkaloid (pa) content of the plant, and the calves’ responses were measured by clinical signs, serum enzyme changes, survival time, and histopathologic changes.

Calves fed S riddellii to provide 10 mg of pa/kg of body weight/day in capsules or by gavage for 20 consecutive days did not develop clinical signs of seneciosis and did not have meaningful serum enzyme changes. However, feedings of the plant that provided 15 to 20 mg of pa/kg/day or more (gavaged or fed in capsules for the same time period) resulted in high mortality.

The Senecio plant mixed in calves’ hay ration was eaten slowly and reluctantly and was tolerated at dosages > 20 mg/kg/day, emphasizing that the toxicity was dependent on the rate at which the dosage was consumed and that mortality was not necessarily dependent on the cumulative dosage.

Because of its high pa content, S riddellii presents a great hazard to cattle managed under conditions where they can consume quantities of the plant in short periods of time.
Dose-response evaluation of a genetically engineered foot-and-mouth disease virus polypeptide immunogen in cattle
Authors: McKercher Peter D. , Moore Douglas M. , Morgan Donald O. , Robertson Betty H. , Callis Jerry J. , Kleid Dennis G. , Shire Steven J. , Yansura Daniel G. , Dowbenko Donald , Small Barbara
Published: February 2025

Four groups of 9 cattle each were vaccinated with 10, 50, 250, or 1,250 μg of foot-and-mouth disease (fmd) virus A12 VP1 fusion protein that was produced in Escherichia coli and emulsified in an oil adjuvant. The groups given the 10 and 50 μg of antigen were revaccinated at 15 weeks and were challenge exposed at 30 weeks; 5 of 9 and 7 of 9 cattle, respectively, were protected from fmd virus infection. The remaining 2 groups, vaccinated with 250 or 1,250 μg of antigen, were revaccinated at 32 weeks and were challenge exposed at 45 weeks; 8 of 9 and 9 of 9 cattle, respectively, were protected. The results indicated that the biosynthetic polypeptide fmd vaccine was effective using vaccination intervals frequently followed with conventional whole-virus vaccines.
Flunixin meglumine attenuation of endotoxin-induced damage to the cardiopulmonary vascular endothelium of the pony
Authors: Turek John J. , Templeton Charles B. , Bottoms Gerald D. , Fessler John F.
Published: February 2025

Endotoxic shock was induced in 5 ponies by intraperitoneal injections of 20, 40, 60, 80, and 80 μg of Escherichia coli endotoxin (lps)/kg of body weight at 0, 6, 12, 18, and 24 hours, respectively. At 24 hours, the ponies also were given 20 μg of lps/kg via catheter in the left ventricle of the heart. A 2nd group of 4 ponies was given 1.1 mg of flunixin meglumine (fm)/kg, iv, at 6, 12, 18, and 24 hours just before the corresponding lps injection. Two hours after the 24-hour lps injection, the ponies in both groups were anesthetized, the lungs were perfused with fixative, and portions of the pulmonary arteries and veins and right and left ventricles were prepared for scanning and transmission electron microscopy. In ponies that were given only lps, some areas of pulmonary vascular endothelium appeared normal when compared with untreated controls, but other areas had disoriented endothelial cells or had varying amounts of sloughing, which ranged from focal areas of a few cells to large areas of denuded endothelium. Ponies treated with fm before lps had less severe and less extensive endothelial cell damage. In both groups, leukocytes were attached to areas of the vessel wall; endothelial cell damage was greater in these regions. Administration of fm before lps administration attenuated the lps-induced endothelial cell damage.
Capacitively coupled electrical stimulation of bone healing in the horse: In vivo study with a Salter type IV osteotomy model with stainless steel surface electrodes
Authors: Collier M. A. , Kallfelz F. A. , Rendano V. T. , Krook L. P. , Schryver H. F.
Published: February 2025

The use of capacitively coupled low-voltage signals for stimulation of osteogenesis has been reported in a variety of animal models. Electrically induced osteogenesis was investigated with a capacitively coupled electric field on a radius (distal-lateral orientation) osteotomy model, in conjunction with internal fixation and postoperative loading. Twelve adult horses of either sex were allotted to 2 groups of 6; 1 group was given electrical stimulation and the other served as controls. A low-voltage high-frequency capacitively coupled electrical signal was locally and continuously applied to the electrically stimulated group for 60 days through external, bare stainless steel surface electrodes which were placed on the skin in circuit with a small, portable power source. Harness compatibility and stimulator and battery durability were excellent. However, stainless steel electrodes required a rigid maintenance schedule to maintain consistent current levels. Synovial fluid evaluation demonstrated intra-articular inflammation (decreased viscosity, hyaluronic acid, and increased protein concentration) 1 week postoperatively that generally improved during subsequent weeks and no distinction between groups was observed at 60 days. Radiographically, there was no difference in the appearance of the healing process of control and that of stimulated horses during the 60 days. Angiography showed bridging blood vessels in both groups. Uptake of a bone seeking radiopharmaceutical peaked at 3 weeks in both groups and was 1.92 ± 0.6 cps/pixel/mCi and 1.26 ± 0.40 csp/pixel/mCi for control and stimulated horses, respectively. At any given observation period, uptake in the lesion area was greater in the control group. Ultimate strengths of trabecular bone in 60-day control radii and stimulated radii were 12.64 ± 3.013 and 9.60 ± 3.95 MN/m2, and the flexural moduli of elasticity were 698.0 ± 423 and 402.0 ± 523 MN/m2, respectively. Porosity index was similar for all specimens. Gross, histologic, and microradiographic evaluations indicated that controls healed more efficiently than stimulated horses. A capacitively coupled applied voltage of 2.2 V RMS (mean) producing a current of 17.32 mA (mean) did not stimulate sufficient bone production in a metaphyseal osteotomy model to affect the mechanical properties of the bone or accelerate the healing process.
Enzymatic and acidic sensitivity profiles of selected virulent and attenuated transmissible gastroenteritis viruses of swine
Authors: Chen Ker-Sang
Published: February 2025

This study identifies the in vitro differences (markers) between virulent and attenuated transmissible gastroenteritis (tge) viruses.

Exposure of virulent Miller strain and attenuated Purdue strain tge viruses to a spectrum of acidities indicated that the Miller strain was more stable at pH 2. Acidities at or above pH 3 did not reduce viral infectivity of either strain. When virulent and attenuated viruses were exposed to gastric fluids of either fed or fasted swine, there was a similar degree of sensitivity. Carboxypeptidase B, α-amylase, and alkaline phosphatase present in porcine small intestinal fluids did not cause a significant difference in sensitivity between virulent and attenuated virus isolates.

The digestive enzymes: trypsin, α-chymotrypsin, pancreatin, peptidase, and carboxypeptidase A did not (or only slightly) inactivate virulent Miller strain tge virus, but greatly reduced infectivity of attenuated viruses (Purdue strain and tge vaccine virus isolates). The attenuated strains were significantly more sensitive to small intestinal fluids from both fasted and fed adult swine. Differential sensitivities between virulent and attenuated tge viruses to digestive fluids from stomach and small intestine further substantiate the notion of differential susceptibility to small intestinal proteases as a correlate of viral virulence.
Laboratory evaluation of aqueous humor in the healthy dog, cat, horse, and cow
Authors: Hazel Stewart J. , Thrall Mary Anna Hull , Severin Glenn A. , Lauerman Lloyd H. , Lavach J. D.
Published: February 2025

Using routinely available clinical laboratory methods, aqueous humor samples were evaluated from 12 healthy dogs, 15 healthy cats, 7 healthy horses, and 6 healthy cows. Aqueous humor was almost acellular; cells that were present had degenerated beyond recognition. Protein concentration was low; only albumin was detectable on electrophoresis. Creatine phosphokinase and lactate dehydrogenase isoenzymes were not detected. Artifacts induced by sampling were insignificant compared with alterations in aqueous humor composition that occur with ocular diseases.
Effects of aspirin and propranolol alone and in combination on hemostatic determinants in the healthy cat
Authors: Allen D. G. , Johnstone I. B. , Crane S.
Published: February 2025

The effects of aspirin (75 mg orally/average-size cat) and propranolol (5 mg orally every 8 hours/average-size cat) alone and in combination on hemostatic determinants in healthy cats were studied. In cats, aspirin alone did not cause a significant effect in platelet numbers, plasma fibrinogen, activated partial thromboblastin time, prothrombin time, thrombin time, or platelet aggregation response to adenosine diphosphate. Aspirin did, however, significantly reduce the degree of aggregation induced by acid soluble collagen.

Propranolol alone or in combination with aspirin did not cause a significant effect on platelet numbers, plasma fibrinogen, activated partial thromboblastin time, prothrombin time, thrombin time, or platelet aggregation in response to acid soluble collagen, adenosine diphosphate, or adrenaline.

It was concluded that aspirin alone at the recommended dosage of one-quarter of a 5-grain tablet (1.25 grains or 75 mg) every other day will significantly affect platelet function and may be of value in the prevention of thromboembolic disease in the cat.
Prevalence of some internal parasites recovered at necropsy of Thoroughbreds born in 1982 in Kentucky
Authors: Lyons E. T. , Tolliver S. C. , Drudge J. H. , Swerczek T. W. , Crowe M. W.
Published: February 2025

A total of 89 Thoroughbreds, 14 to 333 days old (born in 1982), were examined at necropsy for certain internal parasites during a 1-year-period, Mar 1, 1982, to Feb 28, 1983. The eyes of 73 of the horses and the cranial mesenteric arteries of 71 were examined.

Specific interest was on prevalence of parasites according to month of the year and age of the horses at necropsy. Parasites recovered (first month – last month infected horse found) were as follows: Thelazia lacrymalis (eyes) immature and mature (June – February); Habronema/Draschia (lungs) immature (May – September); Habronema muscae (stomach) immature (July – February) and mature (September – February); Draschia megastoma (stomach) immature (August – December), mature (August – February), and lesions (September – February); Gasterophilus intestinalis (stomach) 2nd instars (July – February) and 3rd instars (August – February); Gasterophilus nasalis (stomach) 2nd instars (August – November) and 3rd instars (August – February); Parascaris equorum (lungs) immature (March – November), P equorum (small intestine) immature (March – February), and mature (July – February); Strongyloides westeri (small intestine) mature (March – September); Anoplocephala perfoliata (cecum) immature and mature (August – February); Strongylus vulgaris (cranial mesenteric artery) immature and mature (May – February).

Other parasites recovered, but only from 1 or 2 horses each (months found in infected horses) were: Thelazia skrjabini (eyes) (October), Dictyocaulus arnfieldi (lungs) (January); Trichostrongylus axei (stomach) (October); Anoplocephala magna (small intestine) (October, November); S vulgaris (cecum) (November); Strongylus edentatus (cecum) (January); Setaria spp (abdominal cavity) (January).

Influence of probable chemotherapy of the horses on prevalence of the parasites is discussed.
Comparison of rectal mucosal cultures and fecal cultures in detecting Salmonella infection in horses and cattle
Authors: Palmer J. E. , Whitlock R. H. , Benson C. E. , Becht J. L. , Morris D. D. , Acland H. M.
Published: February 2025

Bacteriologic cultures of 65 rectal mucosal samples and 335 fecal samples from 53 horses and 5 cattle shedding Salmonella were performed. Salmonella spp were isolated from 34 (52%) rectal mucosal samples, 21 (32%) concurrent fecal samples, and 150 (45%) total fecal samples. The use of rectal mucosal samples when compared with concurrently obtained fecal samples significantly (P < 0.025) improved the ability to isolate Salmonella spp. Concurrent bacteriologic culture of rectal mucosal samples and fecal samples resulted in 39 (60%) isolations. Compared with a series of fecal samples, Salmonella was isolated significantly more often when rectal mucosa and feces were cultured concurrently. Salmonella was isolated from rectal mucosal samples when it was not isolated from feces.
Brachygnathia in a herd of Angus cattle
Authors: Heidari Manijeh , Vogt D. W. , Nelson S. L.
Published: February 2025

Seven cases of brachygnathia in a single calf crop (28 calves) were observed in an Angus herd. Two of the affected calves, 1 female and 1 male, were necropsied and anatomically described. Breeding histories and results of pedigree analysis involving the 7 affected calves indicated the cause of the defect to be genetic with the mode of inheritance that of a single autosomal recessive gene.
Prednisolone succinate and prednisolone acetate in cattle: Pharmacokinetics and action on the adrenal gland
Authors: Toutain P. L. , Koritz G. D. , Alvinerie M. , de Pomyers H. , Ruckebusch Y.
Published: February 2025

The pharmacokinetics of prednisolone were studied in a group of 6 cows given prednisolone 21-sodium succinate iv and im (600 μg/kg of body weight expressed as prednisolone alcohol) and prednisolone acetate im (600 μg/kg of body weight expressed as prednisolone alcohol). After iv administration of prednisolone 21-sodium succinate, the half-life of elimination was 3.6 ± 1.177 hours. After im administration of prednisolone 21-sodium succinate, absorption was rapid and complete. After im administration of prednisolone acetate, absorption was very slow with an absorption half-life of 48 hours, but was still complete. Basal plasma hydrocortisone was about 7.5 ng/ml. After iv and im administration of prednisolone 21-sodium succinate, plasma hydrocortisone returned to normal values within 48 hours. In contrast, after im administration of prednisolone acetate, a long adrenal suppression lasting from 4 to 6 weeks was observed.
Phenolsulfonphthalein test in healthy sheep and in sheep with reductions in functional renal mass
Authors: Filippich Lucio J. , English Peter B. , Ainscow Janet
Published: February 2025

The phenolsulfonphthalein (psp) plasma clearance and urinary excretion tests were applied to sheep before and after 50% and 75% reductions in functional renal mass. The PSP determinants found most useful as indicators of renal mass reduction were the 15-minute urinary excretion percentage and the 60-minute (psp60) plasma concentration. Although both of these determinants could be used to detect renal mass reduction, the 15-minute psp excretion percentage was the more sensitive. The (psp60) value was influenced by factors other than reduced nephron numbers; the contraction of the psp volume of distribution that occurred after renal mass reduction was one important influencing factor. Overall, the psp tests more accurately reflected the volume of blood delivered to the kidney than the proximal tubular secretory capacity.
Serum amylase and isoamylases and their origins in healthy dogs and dogs with experimentally induced acute pancreatitis
Authors: Murtaugh R. J. , Jacobs R. M.
Published: February 2025

Agarose-gel electrophoresis was used to study isoamylases in tissues and sera of healthy dogs and the sera of dogs with experimentally induced acute pancreatitis. Three or 4 isoamylases were found in the serum of healthy dogs; they were numbered 1 to 4 with respect to their degree of anodal migration. Peak 4 isoamylase, the slowest migrating (most cathodal), was the major isoamylase fraction in sera and tissues of healthy dogs. Peak 3 was identified as a pancreas-specific isoamylase.

Absolute total serum amylase and total isoamylase concentrations increased significantly in dogs with pancreatitis compared with values for control dogs (sham-operated). The relative increase in peak 3 isoamylase was greater than that seen with total amylase or the other isoamylases. The decrease in total serum amylase and isoamylase concentrations paralleled each other; however, peak 3 remained proportionally high longer than did total amylase and the other isoamylase fractions.

These findings indicate that measurement of peak 3 isoamylase concentrations may be of diagnostic value in dogs with suspected pancreatitis with normoamylasemia and in dogs with extrapancreatic hyperamylasemia.
Comparative efficacy of injection routes and doses of ivermectin against Psoroptes in rabbits
Authors: Wright Fred C. , Riner Jayme C.
Published: February 2025

Rabbits infested with Psoroptes ovis (Hering) or with P cuniculi (Delafond) were injected im or subcutaneously with ivermectin or with vehicle. A single injection of ivermectin (200 μg/kg) either im or subcutaneously was inadequate to eliminate all mites in the ears of the rabbits. However, a single injection of ivermectin at 400 μg/kg, regardless of the route of injection, eliminated all P cuniculi mites, but eliminated P ovis mites in only 50% of the rabbits. Ivermectin was more effective against P cuniculi than against P ovis at both doses tested, regardless of the route of injection.
Factors associated with the spread of clinical vesicular stomatitis in California dairy cattle
Authors: Hansen Donald E. , Thurmond Mark C. , Thorburn Margaret
Published: February 2025

In 1983, vesicular stomatitis entered the state of California through infected cattle purchased in Idaho and sold to 5 California dairies. This study examined management, environmental, and host factors which were thought to be associated with disease spread. The use of coarse roughage and hard-pelleted concentrates, the presence of uneaten feed potentially contaminated with virus-laden saliva, increased interpen movement of cows, poor ground surface conditions, poor milking hygiene, and poor teat sanitation were management factors observed to be associated with clinical signs. The amount of milk production, age, or days in milk of individual cows seemed to have an important role in the spread of clinical disease. Recommendations are given for control and prevention of clinical signs and, therefore, the severity of disease during epizootics of vesicular stomatitis in California dairies.
Effects of atropine on xylazine-pentobarbital anesthesia in dogs: Preliminary study
Authors: Hsu Walter H.
Published: February 2025

The influence of atropine on anesthesia induced by xylazine-pentobarbital administration was studied in 5 dogs. The combination of xylazine (2.2 mg/kg of body weight, im) and pentobarbital (14.0 mg/kg, iv) caused anesthesia with the duration of absence of the pedal reflex, duration of anesthesia, and the time from return of consciousness to ambulation to be 107.4, 123.4, and 59.2 minutes, respectively. Bradycardia and short-term respiratory depression were observed. An im injection of atropine sulfate (0.045 mg/kg) did not significantly change the durations of absence of the pedal reflex and of anesthesia, the time from return of consciousness to ambulation, or the pattern of respiration in the anesthetized dogs. The PaO2 increased gradually in both groups; however, atropine caused a marked tachycardia and increased the PaCO2. Fifteen minutes after pentobarbital injection, administration of atropine sulfate caused a slight but significant (P < 0.01) decrease in arterial pH. Although atropine sulfate antagonized xylazine bradycardia, the data indicated that it may have caused increased respiratory depression in dogs anesthetized with xylazine and pentobarbital.
Use of nonprotein nitrogen in pigs; Effects of dietary urea on the intestinal microflora
Authors: Benno Y. , Endo K. , Suzuki K. , Mitsuoka T. , Namioka S.
Published: February 2025

The fecal flora of 2 pigs given an optimal protein diet (digestive crude protein, 13.3%) with 2% urea, 2 pigs given a low protein diet (digestive crude protein, 5.7%) with 2% urea, and 2 pigs given a low protein diet only were bacteriologically investigated before feeding of each diet and on feeding days 21 and 38. The addition of urea to a low protein diet was significantly decreased Lactobacillus (P < 0.001), Bacteroidaceae (P < 0.01), Peptococcaceae (P < 0.05), and Megasphaera (P < 0.01) in the feces. In addition, there was a marked suppression of anaerobic curved rods (mainly Selenomonas) to undetectable amounts in the feces. A significant reduction (P < 0.01) of Bifidobacterium and a marked suppression of Megasphaera to undetectable amounts were observed in the feces of pigs given low protein diets without urea.

Microbial groups in the ileum and colon of pigs on feeding day 38 were also analyzed. Effects of dietary urea on the intestinal flora included: (i) anaerobic curved rods and spiral rods were restricted mainly to the colon, (ii) smaller numbers of yeasts were present in the intestine, and (iii) Bacteroidaceae, Peptococcaceae, and Eubacterium in the colon were not changed. Many anaerobic isolates, including curved rods and spiral rods, in the colon of pigs may have an important role in urea use.
Use of epidemiologic markers to identify the source of Escherichia coli infections in poultry
Authors: Barbour E. K. , Nabbut N. H. , Al-Nakhli H. M.
Published: February 2025

During an epidemiologic study of poultry colisepticemia on 2 Saudi Arabian poultry broiler farms, Escherichia coli was isolated from 101 (40.4%) of the 250 specimens examined. The antigenic structure and the drug resistance pattern of 65.4% of the E coli isolates from different sources were used as epidemiologic markers to trace the source of the infection. The predominant E coli serotypes involved in infections of 2 poultry broiler progeny farms were 033:H4 (51.8%) and 078:H- (19.6%) that had the following respective drug resistance patterns: furazolidone-streptomycin-sulfathiazole and streptomycin-sulfathiazole-tetracycline. Escherichia coli strains with typical epidemiologic markers were isolated from various sources on a broiler breeding farm, but not from well waters of the infected progeny farm. Three other E coli serotypes (045:H10[14.3%], 0119:H27[1.8%], and 0145:H25[1.8%]) were involved in poultry infection, but to a lesser extent. These 3 serotypes were multiply resistant against 5 to 6 of the antimicrobials evaluated.
Immunogenicity of Moraxella bovis hemolysin
Authors: Ostle A. G. , Rosenbusch R. F.
Published: February 2025

Anti-Moraxella bovis hemolysin activity was observed in 35 cattle exposed to field infections of infectious bovine keratoconjunctivitis (ibk). All cattle in infected herds seroconverted with respect to antihemolysin whether or not clinical ibk was noted. Cattle previously exposed to ibk possessed higher antihemolysin titers than did younger, nonexposed cattle. Antihemolysin activity was noted in bovine sera up to 7 years after exposure to ibk. Sera from experimentally infected calves were found to possess antihemolytic activity against all 33 strains of M bovis tested. Antihemolytic activity could be demonstrated in random-bred mice inoculated with whole doxycycline-treated M bovis, frozen or lyophilized whole M bovis, and membrane fractions treated with sodium lauryl sarcosinate, Triton × 100, and Triton × 100 + EDTA, but not with formalin-treated whole M bovis.
Serologic evaluation of cattle inoculated with Toxoplasma gondii: Comparison of Sabin-Feldman dye test and other agglutination tests
Authors: Dubey J. P. , Desmonts George , McDonald Connie , Walls K. W.
Published: February 2025

Six cows and 6 calves were each inoculated with 100 or 100,000 Toxoplasma gondii oocysts. Serum samples were analyzed, using the Sabin-Feldman dye test (dt), indirect hemagglutination test, latex agglutination test, and the modified direct agglutination test (mat). Antibody titers in cows were lower than in calves. In the cows, dt titers increased briefly during the first month after inoculation, after which the titers were negative; however, T gondii was isolated from the tissues of 4 cows. Indirect hemagglutination and latex agglutination titers were generally < 1:256. The mat titers increased to 1:1,024 during the first month after inoculation. In 5 of the 6 cows, the mat titers persisted. The 6th cow had a preinoculation mat titer of 1:2,000 for 3 to 6 months. Therefore, the dt was not useful in serologic surveys for T gondii in cattle; the mat was the most sensitive test and may be useful in the diagnosis of T gondii infection in cattle.
Prospective study of progeny of inapparent equine carriers of equine infectious anemia virus
Authors: Issel C. J. , Adams W. V. , Foil L. D.
Published: February 2025

Progeny of a band of horses, positive by the agar-gel immunodiffusion (agid) test for equine infectious anemia (eia) antibody, were observed through their weaning over a 4-year period. Sentinels (agid test-negative) were allowed to mingle with eia-infected mares and their foals in pasture situations in an area with high populations of potential vectors. Of 27 adult sentinels, 8 (30%) seroconverted in annual rates ranging from 0% to 75%. In contrast, only 2 of 31 (6%) foals weaned became infected. Difference in infection rates between adult sentinels and foals was significant (χ2, P < 0.05). Possible explanations for differences included protective value of colostral immunity and differences in attractiveness to blood feeding vectors. Detectable colostral immunity to eia virus in the agid test persisted for 25 to 195 days, with a mean of 124 days.
DNA hybridization procedure to detect pseudorabies virus DNA in swine tissue
Authors: McFarlane Robin G. , Thawley David G.
Published: February 2025

A DNA hybridization technique was developed to detect the presence of pseudorabies virus (prv) DNA. 32P Nick translated probes of high specific activity were prepared from transformed Escherichia coli plasmids into which Bacillus amyloliquefaciens H (Bam H1) restriction fragments of prv DNA had been inserted. Swine cellular DNA and tissue culture prv DNA were digested with Bam H1, separated by agarosegel electrophoresis, transferred onto nitrocellulose paper, hybridized to the radioactive probes, and washed under high stringency conditions; autoradiographs were then prepared. Under the optimal hybridization conditions described, the detection limit of these probes was 10-11g of prv DNA. In reconstruction experiments, 3 of the selected probes cross hybridized with digested swine cellular DNA, and 4 probes did not. The addition of polyuridylic acid and polyguanylic acid to the hybridization reactions did not alter the amount of hybridization. The results indicated that this procedure may be useful for studying the latency of pseudorabies viral infection.
Comparison of three suture techniques for anastomosis of the small intestine in the horse
Authors: Dean Paul W. , Robertson James T.
Published: February 2025

Seven horses were used to compare the Gambee, the crushing, and a 2-layer inverting suture pattern composed of a simple continuous layer in the mucosa oversewn with a continuous Lembert pattern in the seromuscular layer. Horses were evaluated at 30 days for adhesion formation, lumen diameter, and quality of healing at the anastomotic sites.

One horse was euthanatized 9 days after surgery after 24 hours of ileus and colic; necropsy revealed septic peritonitis and widespread adhesions. One horse had no adhesions. The remaining horses had adhesions associated with 50% of the Gambee and 50% of the crushing anastomoses. There were no adhesions related to the 2- layer inverting techniques in these 6 horses.

There was no significant difference in percentage reduction of lumen diameters between the 3 techniques, and there was no evidence of chronic obstruction resulting from any of the anastomotic techniques. Histologically, the inflammatory response and fibrosis were minimal in the single layer patterns, but there was increased fibrosis and suture tract inflammation in the 2-layer inverting technique.
Echocardiography reference values in healthy cats sedated with ketamine hydrochloride
Authors: Fox Philip R. , Bond Betsy R. , Peterson Mark E.
Published: February 2025

An M-mode echocardiography examination was performed in a consistent manner in 30 clinically healthy cats under light ketamine hydrochloride sedation. There was a significant linear relationship between increasing body size and increasing cardiac dimensions for several echocardiographic values. Positive correlation existed between body weight and body surface area with aortic root, left ventricular caudal wall thickness (lvcw), interventricular septal thickness (ivs), ivs/lvcw, and mean velocity of circumferential fiber shortening (Vcf); there was a negative correlation between body weight and body surface area with left ventricular ejection time (lvet). Body surface area also correlated positively with percentage of ventricular minor axis dimensional change (%ΔD). Positive correlations were recorded between left ventricular end-diastolic dimension (lvedd) and left ventricular end-systolic dimension (lvesd), lvesd and lvet, lvcw and rvs, lvet (calculated by lvcw motion) and lvet (calculated by aortic valve motion), %ΔD and Vcf, heart rate and Vcf, and Vcf (calculated using aortic valve motion to compute lvet) and Vcf (using lvcw motion to compute lvet). There were negative correlations between lvedd and %ΔD, lvedd and Vcf, lvesd and Vcf, lvet and Vcf, lvet and heart rate, lvet and %ΔD. Significant differences were recorded between means of echocardiographic reference values generated in this and other studies, except for lvesd.
Effect of diuresis on urinary excretion and creatinine clearance in the horse
Authors: Gronwall Ronald
Published: February 2025

Endogenous creatinine clearance and renal excretion of phenylbutazone, osmotically active material, and compounds contributing to the urinary refractive index were studied in 12 Thoroughbred mares after no treatment, after water administration, or after furosemide administration. Urine was quantitatively collected, using urinary bladder catheters. On average, urine flow of the mares was 9 μl/min/kg without treatment and increased to about 50 μl/min/kg after water administration and to about 70 μl/min/kg after furosemide administration. Water administration increased creatinine clearance values and excretion of phenylbutazone. Furosemide administration increased urinary excretion of osmotically active compounds and compounds contributing to urinary refractive index and decreased excretion of phenylbutazone.
Change in M-mode echocardiographic values in cats given ketamine
Authors: Jacobs Gilbert , Knight David H.
Published: February 2025

Determination was made of changes in heart rate and certain M-mode echocardiographic values in healthy cats given ketamine (3 to 5 mg/kg, im). Heart rate and septal and left ventricular posterior wall thickness in diastole increased, and left ventricular internal diameter in diastole and shortening fraction decreased (P < 0.02) after ketamine was given. With the adjustment for heart rate by analysis of covariance, left ventricular internal diameter in diastole, shortening fraction, and velocity of circumferential fiber shortening were significantly decreased (P < 0.05) from base-line values.
Influence of nifedipine on xylazine-induced acute pressor response in halothane-anesthetized dogs
Authors: Tranquilli W. J. , Thurmon J. C. , Paul A. J. , Benson G. J.
Published: February 2025

Effects and interaction of nifedipine (Ca channel blocker) and xylazine (mixed α agonist) during halothane anesthesia were examined in 6 dogs. After achievement of steady-state halothane (1.35%) anesthesia, blood pressure (bp) and heart rate (hr) were recorded in these dogs during 3-minute saline or nifedipine (20 μg/kg) infusion periods. Seven minutes after the end of saline or nifedipine infusion, xylazine (1.1 mg/kg of body weight) was infused over a 2-minute period. After saline pretreatment, xylazine administration increased diastolic bp (33.67 ± 3.91 mm of Hg) and decreased hr. Nifedipine infusion induced a transient reduction in bp, accompanied by a more persistent increase in hr. Compared with saline pretreatment, nifedipine pretreatment significantly decreased the acute increase in diastolic bp (33.67 ± 3.91 vs 14.00 ± 2.94 mm of Hg) which occurred during xylazine injection. After saline and nifedipine infusions, xylazine administration decreased hr 30 ± 15.02 and 36.5 ± 10.36 beats/min, respectively. A pronounced sinus arrhythmia and/or 2nd-degree atrioventricular block developed in all dogs during xylazine injection after saline infusion. Arrhythmias were not observed in the dogs after nifedipine infusion.

Nifedipine's Ca blocking action depressed xylazine-induced acute vasoconstriction and concomitant increase in diastolic bp. Because α2−, but not α1-adrenoceptor-mediated vasoconstriction is Ca-dependent, these results indicate that a portion of the acute pressor response induced by iv xylazine in halothane-anesthetized dogs may be α2− mediated. Seemingly, nifedipine-induced hypotension and damping of xylazine-induced increases in bp attenuated xylazine's actions on cardiac rate and rhythm.
Lymph drainage of the conjunctiva: Topographic anatomic study in calves
Authors: Freeman L. E. , Troutt H. F.
Published: February 2025

The topographic pattern of lymph drainage from the conjuctiva was ascertained in 1- to 2-week-old calves. Multiple, small lymph vessels within and on the surface of the orbicularis oculi muscle converged to form fewer vessels which followed the course of the superficial temporal artery and vein or crossed the zygomatic arch in a more rostral position to reach the primary site of lymph collection, the parotid lymph node. Marker dye, injected into the subconjunctiva, was collected in the midrostral and rostroventral parts of the node. Drainage from the parotid node passed via multiple lymph vessels into the lateral retropharyngeal node, where marker dye concentrated in the rostrodorsal aspect of the node. Single or multiple lymph vessels carried drainage from the lateral retropharyngeal node indirectly by way of the cranial deep cervical lymph node or directly into the tracheal lymph trunk.
Ovarian lesions induced in heifers by intravenous inoculation with modified-live infectious bovine rhinotracheitis virus on the day after breeding
Authors: Van Der Maaten M. J. , Miller J. M. , Whetstone C. A.
Published: February 2025

Four commercially available vaccine strains of modified-live infectious bovine rhinotracheitis virus were passaged once in embryonic bovine kidney cells. Heifers were inoculated iv on the day after breeding with 5.0 ml of nondiluted cell culture fluid of each of the 4 strains. Virus was reisolated from nasal swabs and blood collected during the week after inoculation. The heifers were killed 9 to 14 days after inoculation. Mild-to-marked inflammatory and necrotic lesions were seen in the corpora lutea and ovaries of the heifers. The lesions were similar to, and almost as severe as, those resulting from the inoculation of virulent strains of infectious bovine rhinotracheitis virus. Adrenal lesions were also found in all heifers examined. Virus was reisolated from the ovaries of only 4 of the 8 heifers. However, virus was confirmed in the ovaries of all 8 heifers, using immunofluorescent or ultrastructural studies. Heifers with severe luteal damage had abnormally low plasma progesterone concentrations.
Duration of maternally derived antibodies against equine influenza in newborn foals
Authors: Liu Irwin Κ. M. , Pascoe David R. , Chang Lucille W. S. , Zee Yuang Chung
Published: February 2025

Serum antibody concentrations against influenza A-equi-1 virus and A-equi-2 virus were measured in a group of 18 foals from birth to 4 months of age. More than 50% of the foals were seronegative to A-equi-1 virus infection by 4 weeks of age, with titers of ≤ 1:16. For A-equi-2 virus, more than 50% of the foals were seronegative by 2 weeks of age, with titers of ≤ 1:8. Passively derived antibodies against influenza A-equi-1 virus and A-equi-2 virus in foals obtained from recently vaccinated mares and from mares not vaccinated within 6 months before foaling were low in titer. The duration of passively derived antibodies was also short-lived.
Healing of surgically created defects in the equine superficial digital flexor tendon: Collagen-type transformation and tissue morphologic reorganization
Authors: Watkins J. P. , Auer J. A. , Gay S. , Morgan S. J.
Published: February 2025

Full-thickness defects were surgically created in the superficial digital flexor tendons of the front limbs of 20 horses. Tissues formed within the defect were evaluated histologically, and the collagen composition of the tissue was determined by immunofluorescence. Transformation occurred from loose fibrillar areas of types I and III collagen and pericellular types IV and V collagen to dense bundles of type I collagen fibers. Loose fibrillar areas of types I and III collagen were present after 24 weeks. Histologically, in horses killed after 2 weeks, the tissue within the defect was a randomly oriented mass of fibrovascular tissue. In horses killed after 24 weeks the tissue within the defect resembled normal tendon tissue.
Estimation of quantitative proteinuria in the dog, using the urine protein-to-creatinine ratio from a random, voided sample
Authors: Grauer Gregory F. , Thomas Chester B. , Eicker Steven W.
Published: February 2025

The correlation between 24-hour urine protein excretion and the protein-to-creatinine ratio (u-p/c) from random, voided urine specimens was assessed in 16 healthy Beagles (9 to 11 months old) and in 14 dogs with suspected renal proteinuria. Initially, a voided urine specimen was obtained from each dog, and the u-p/c was determined. An attempt was not made to standardize the time of collection of the voided urine. Subsequently, each dog was placed in a metabolism cage, and 24-hour urine specimens were collected for quantitative protein analysis. The Coomassie blue technique was used to measure urine protein. The correlation between the u-p/c and the 24-hour urine protein excretion (mg/kg/ 24 hr), evaluated by linear-regression analysis, was found to be significant (r = 0.975, P < 0.01). These results substantiate previous findings and indicate that random, voided urine specimens may be used to compute the ratio and to accurately reflect 24-hour urinary protein loss in the dog.
Extracutaneous histologic changes accompanying zinc deficiency in pups
Authors: Sanecki R. K. , Corbin J. E. , Forbes R. M.
Published: February 2025

The extracutaneous tissues in pups fed a Zn-deficient diet were examined. Four pups were fed a Zn-deficient diet and 3 littermates were fed a Zn-adequate diet. After 5 weeks, the pups were euthanatized. Lesions found only in pups fed a Zn-deficient diet were located in the buccal mucosa, lymph nodes, spleen, and thymus. In the buccal mucosa, lesions consisted of irregular epithelial hyperplasia and disruption of epithelial cell layers. There was a marked absence of lymphocytes in the thymus and in T-cell areas of the lymph nodes and spleen.
Indirect auscultatory systolic and diastolic pressures in the anesthetized dog
Authors: Wessale Jerry L. , Smith Lee Ann , Reid Miles , Janas Wolfgang , Carter Alice B. , Geddes Leslie A.
Published: February 2025

The auscultatory method was used to obtain indirect systolic and diastolic pressures in 13 dogs anesthetized with either halothane or sodium pentobarbital (30 mg/kg of body weight). Korotkoff sounds were obtained, using a 1-cm (diameter) piezoelectric element cemented to the inner surface of a pediatric cuff (width 5.5 cm) which was placed on a shaved thoracic limb (membrum thoracicum). The signal from the piezoelement was amplified by a differential amplifier (30 to 200 Hz) and a commercially available audio amplifier. Indirect pressure (I) was compared with direct pressure (D) in the brachial, femoral, or carotid artery. The linear regression lines and correlation coefficients (r) for the data were as follows: systolic, I = 0.94 (D) + 1.1, r = 0.98; diastolic, I = 0.99 (D) + 3.2, r = 0.99. The quality of the Korotkoff sounds and the accuracy of the determinations were best in the halothane-anesthetized dogs. These results indicate that indirect auscultatory systolic and diastolic pressures are in excellent agreement with the directly measured pressures.
In vitro phagocytosis and killing of Corynebacterium equi by alveolar macrophages of foals
Authors: Zink M. C. , Yager J. A. , Prescott J. F. , Wilkie B. N.
Published: February 2025

Bronchoalveolar lavage was performed 5 times, sequentially, on 3 healthy foals while each foal was 6 to 63 days of age. Phagocytosis and bactericidal assays were performed on recovered alveolar macrophages. Corynebacterium equi and alveolar macrophages at a ratio of 10:1 were incubated for 1 hour in medium containing 1% heat-inactivated rabbit anti-C equi serum. After incubation, > 90% of the alveolar macrophages contained at least 1 ingested bacterium and each alveolar macrophage contained 9.4 ± 1.0 bacteria (mean ± se). After alveolar macrophages and C equi were incubated for 1 hour in medium containing heat-inactivated pooled normal horse serum, approximately 24% of the alveolar macrophages contained at least 1 bacterium and each alveolar macrophage contained 0.8 ± 0.7 bacteria. From 6 to 61 days of age, each foal had significantly (P < 0.05) decreased phagocytic activity by alveolar macrophages, but a significant change in killing of C equi by alveolar macrophages was not found in the foals from 21 to 61 days of age. After incubating alveolar macrophages and C equi for 4 hours in vitro, approximately 75% of ingested C equi remained viable.
Experimentally induced ostertagiosis in rabbits inoculated with Ostertagia ostertagi of bovine origin
Authors: Snider Theron G. , Williams James C. , Romaire Terry L. , Besch Ε. D.
Published: February 2025

Weanling specific-pathogen-free rabbits were orally inoculated with 50,000 Ostertagia ostertagi 3rd-stage infective larvae cultured from bovine feces and were killed 42 days after inoculation. Two preliminary trials were done, using conventionally reared weanling rabbits inoculated with 2,500, 5,000, and 50,000 Ο ostertagi 3rd-stage larvae and dexamathasone in 1 of the trials; the rabbits were killed 14 and 28 days after inoculation. Fecal egg counts were monitored, and worm burdens were determined. The pH of the gastric contents was measured at necropsy. Recoveries of the parasite from the gastric mucosa comprised early 4th-stage larvae and larvae that had developed beyond the early 4th stage. The maximum worm burden established at 42 days after inoculation was 1,668 immature nematodes or 3.34% of the inoculum. Gross and microscopic gastric lesions were present. Gross nodular mucosal elevations, which tended to be confluent in the cardiac region, were observed. Microscopic changes were principally mucosal hyperplasia, focal lymphocyte accumulation with moderate glandular dilation, and slight variable eosinophil and plasma cell accumulation. The pathologic changes had characteristics similar to those in cattle infected with Ο ostertagi and other conditions characterized by gastric mucosal hyperplasia.