bluuebunny/crossref_metadata_2025 huggingface dataset:
Postadulticide changes in Dirofilaria immitis-infected Beagles
Authors: Rawlings C. A. , Losonsky J. M. , Schaub R. G. , Greene C. E. , Keith J. C. , McCall J. W.
Published: February 2025

Clinical, hematologic, arteriographic, radiographic, and morphologic responses to dying heartworms were characterized in 7 heartworm-infected Beagles after adulticide treatment. The Beagles had been infected 27 or 31 months previously with 99 or 100 infective Dirofilaria immitis (di) larvae. These dogs had di-induced pulmonary hypertension and pulmonary arteriographic and radiographic lesions.

Three weeks after adulticide, arteriography revealed intraluminal obstruction of blood flow to the caudal lung lobes. The obstruction to flow in tertiary arteries was worse and the dilatation in main pulmonary arteries was less severe at 3 weeks as compared with that in vessels before administration of the adulticide. Radiographically, focal areas of increased parenchymal densities developed about these caudal lobar arteries in all dogs after adulticide treatment. These lesions had decreased in severity by day 36 in all 6 survivors. A mild inflammatory response and occasional stress response were present in the leukograms after adulticide. Alanine transferase and alkaline phosphatase activity increased slightly. Results of coagulation studies, except platelet counts, were normal in all dogs.

At necropsy, none of the worms was alive, and all fragments of dead worms were in smaller branches (< 10 mm diameter), particularly in the right caudal lobe. Endothelial permeability was less in the large arteries as compared with that in dogs infected with live heartworms, but was more in the smaller arteries (< 10 mm diameter). These small arteries contained the dead heartworms and were within the area of increased parenchymal density, as seen radiographically. Scanning electron microscopy revealed changes on the surface of the large arteries that are typical for resolution of the villi of myointimal proliferation. Smaller arteries (< 10 mm diameter) had severe villus proliferation, especially in areas surrounding the dead fragments.
Staphylococcal protein A labeled with horseradish peroxidase for the immunohistologic diagnosis of canine autoimmune diseases
Authors: Seiler Robert J.
Published: February 2025

Protein A, (pa) from Staphylococcus aureus conjugated to horseradish peroxidase (po) was used for the immunohistologic diagnosis of various canine autoimmune diseases. The use of pa for this and other immunologic procedures is dependent on the highly specific “pseudoimmune” affinity of pa for the Fc region of immunoglobulins (Ig). In the dog, this specificity is directed mainly toward IgG and to a lesser extent toward IgM. Horseradish peroxidase serves as a convenient marker of specifically localized pa.

Conjugates (po-pa) were prepared by the “improved periodate” method and purified by gel filtration. Typical preparations had an average molecular weight of approximately 120,000 daltons and analysis of the molar ratios of pa and po indicated that conjugates were mostly formed from dimers of pa coupled to single molecules of po. The conjugates were used in direct tests on the skin or kidney of dogs with pemphigus or glomerulonephritis, as well as in indirect tests of sera with antinuclear, pemphigus, bullous pemphigoid, and antithyroid (antithyroglobulin and antimicrosomal) antibodies. In all cases, the appropriate controls were negative and the staining pattern mirrored that seen with the conventional immunofluorescence.

The po-pa staining, as with immunoperoxidase methods, was permanent and may be examined by light microscopy, and the sections may be counterstained. A major advantage of po-pa conjugates was that they could be prepared from standard, easily available laboratory reagents, which should facilitate the standardization of methods in different laboratories. Also, the same conjugates could be applicable to immunohistologic diagnosis in several different animal species. Hence, it was concluded that the po-pa method is a reliable, simple, and useful immunohistologic procedure that should find more widespread use in the future.
Counterimmunoelectrophoresis (immunoelectroosmosis) and serum electrophoretic pattern in serologic diagnosis of canine blastomycosis
Authors: Barta Ota , Hubbert Nancy L. , Pier Allan C. , Pourciau Susan S.
Published: February 2025

Counterimmunoelectrophoresis (ciep) with blastomyces and histoplasma antigens was used in a serologic study of 181 dogs clinically suspected of having blastomycosis and of 8 dogs with confirmed blastomycosis or histoplasmosis. Thirteen of the 181 dogs, positive by ciep, were euthanatized, and the diagnosis was confirmed by cultivation and/or microscopic detection of Blastomyces dermatitidis. Additional ciep-positive dogs were confirmed by staining of aspirates collected in vivo. Radiographic support for the diagnosis was reported in 4 other dogs in which histoplasmosis was excluded by a negative ciep with histoplasma antigen.

The precipitating antibody may disappear during the course of the disease, as it did in 1 dog treated with amphotericin B, but not cured. This dog reverted from ciep-positive to ciep-negative within 17 months of treatment (with a weak reaction after 10 months of treatment). The ciep-detectable antibody was present only in 1 dog without a confirmation by histopathologic findings or cultivation among 24 well-documented cases and 181 total tested sera.

The ciep was more sensitive and specific than was the gel-diffusion precipitin test, eliminated the problems of anticomplementarity that often affected the results of complement-fixation tests with canine sera, and served well in detecting dogs with blastomycosis. Electrophoretic pattern of sera from ciep-positive dogs with blastomycosis showed a decrease in albumin and an increase in in α2- and often in β- and γ-globulins, with a substantial decrease of the albumin/globulin ratio.
Attempted immunization of cats against feline infectious peritonitis, using avirulent live virus or sublethal amounts of virulent virus
Authors: Pedersen Niels C. , Black John W.
Published: February 2025

Kittens vaccinated with an avirulent biotype of the Black strain of feline infectious peritonitis virus (fipv; given oronasally) developed both indirect fluorescent and virus-neutralizing antibodies, but were not protected against oronasal challenge exposure with virulent virus. In fact, kittens vaccinated with avirulent virus were more readily infected than were nonvaccinated cats. A proportion of kittens could be immunized to fipv by giving sublethal amounts of virulent virus. This technique, however, was too inconsistent and hazardous to have clinical relevance.

The results of these studies indicated that humoral immunity was not protective in fipv infection. There was no correlation between fluorescent and virus-neutralizing antibodies and either disease or immunity. Immune serum from fipv-resistant cats failed to passively protect susceptible animals against virulent virus given intraperitoneally or oronasally, and as expected, actually sensitized them to infection. It was concluded that cell-mediated immunity was probably responsible for protection.
Effect of bacterial dose on pneumonia induced by aerosol exposure of calves to bovine herpesvirus-1 and Pasteurella haemolytica
Authors: Yates W. D G. , Jericho K. W. F. , Doige C. E.
Published: February 2025

Sixteen crossbred Hereford range calves were used to study the effects of Pasteurella haemolytica aerosols of various concentrations administered 4 days after they were exposed to a uniform aerosol of bovine herpesvirus-1 (bhv-1).

All calves were given bhv-1 on day 0. On day 4, groups of 4 calves each were exposed to aerosols of P haemolytica generated from suspensions with the following concentrations: high (108/ml)—group 1, moderate (105/ml)—group 2, low (102/ml)—group 3, or none (control)—group 4.

All calves developed clinical signs of respiratory infectious bovine rhinotracheitis. Those in group 4 (controls) and group 3 (low bacterial concentration exposure) were near complete recovery by day 8. At necropsy, most calves in all groups had diphtheritic inflammation of the mucosal surfaces of the upper and lower respiratory tracts and lobular atelectasis of the lung parenchyma. Three of the group 2 calves (exposed to the moderate concentration of P haemolytica) and all group 1 calves became severely ill with fibrinous pneumonia; 3 in the latter group died by day 8.

For the conditions of this experiment, the 50% lethal dose was 1×107.1 bacteria/ml of suspension from which the aerosol was generated and 1 × 105.1 P haemolytica inhaled/calf. The 50% effective dose for fibrinous pneumonia was 1 × 104.1 P haemolytica/ml of suspension and 1 × 102.1 bacteria inhaled/calf. The term “inhaled” was used to mean the number of organisms estimated to be taken into the respiratory tract at the level of the nostrils.

The results indicated that there is a positive relationship between degree of exposure to P haemolytica and severity of pneumonia in this disease model.
Relationship between ingestion of the locoweed Oxytropis sericea and congestive right-sided heart failure in cattle
Authors: James L. F. , Hartley W. F. , Van Kampen K. R. , Nielsen Darwin
Published: February 2025

In field observations of young cattle grazing on certain high-altitude ranges infested with the locoweed Oxytropis sericea, a high frequency of clinical congestive right ventricular failure was identified. At necropsy of affected calves, there were right ventricular hypertrophy and dilation, subcutaneous edema, hydrothorax, diarrhea, and chronic passive congestion of liver. Microscopically, there was neurovisceral foamy cytoplasmic vacuolation, characteristic of locoism.

An experiment was set up to test the relationship of O sericea to congestive right-ventricular failure. Preliminary investigation supports the field observation.
Equine esophageal pressure profile
Authors: Stick John A. , Derksen Frederik J. , McNitt Denise L. , Chou C. C.
Published: February 2025

Esophageal motility was studied in 5 healthy adult horses, using a 4 side-hole catheter assembly continuously perfused with distilled water. Resting pressure and maximal pressures generated during swallowing were measured over the whole length of the esophagus (mean ± Sx = 132.7 ± 2.31 cm). Four functionally distinct regions of the esophagus were demonstrated: cranial esophageal sphincter, caudal esophageal sphincter, and “fast” and “slow” regions in the body of the esophagus.

The resting pressure of the cranial and caudal esophageal sphincters were 171.1 ± 20.45 (x ± Sx) and 10.5 ± 0.61 (x ± Sx) mm of Hg, respectively. The maximal pressure of the “fast” and the “slow” esophageal regions and caudal esophageal sphincter were 63.1 ± 3.75 (x ± Sx), 71.9 ± 3.65 (x ± Sx), and 63.1 ± 2.60 (x ± Sx) mm of Hg, respectively. The length of each region and duration of pressure events were quantitated, establishing an equine esophageal pressure profile.
Cortisol (hydrocortisone) disappearance rate and pathophysiologic changes after bilateral adrenalectomy in equids
Authors: Slone D. E. , Ganjam V. K. , Purohit R. C. , Ravis W. R.
Published: February 2025

Six ponies and 1 horse were bilaterally adrenalectomized (badx). The survival time of 2 of the 7 animals after badx was 24 and 72 hours without supplemental corticosteroids. The cause of death was not related to the surgical technique. The biological half-life of cortisol (hydrocortisone) was estimated to be 2.1 ± 0.6 hours. The disappearance of cortisol in the horse was found to be biphasic, composed of redistribution and elimination phases. Pathophysiologic changes (ie, increased serum sodium and chloride, increased pcv, and decreased serum potassium) similar to those seen in other species after badx were found. Clearance of electrolytes was calculated, using the creatinine clearance method. These values were inversely correlated with the changes seen in serum electrolytes.
Alveolar lavage in dogs
Authors: Brown Nancy O. , Noone Kathy E. , Kurzman Ilene D.
Published: February 2025

Alveolar lavage was performed in 10 healthy dogs. After tracheal intubation was done, a sterile fiberoptic bronchoscope was wedged in a distant bronchus and the lungs were lavaged with sterile saline solution. An average of 140 ml of saline solution was flushed into the lungs of each dog, and an average of 79% of the solution was recovered. Examination of the recovered fluid revealed average total cell counts of 6.4 × 106 cells/dog. Average differential cell counts were as follows: macrophages, 50.5%; lymphocytes, 46.0%; and neutrophils, 3.5%. Results of bacterial culture of the recovered fluid were negative in 8 dogs and positive in 2; Bordetella bronchiseptica was isolated in 1 dog and Klebsiella pneumoniae was isolated in the other.
Occurrence of secondary systemic amyloid in the pancreatic islets of a cat
Authors: Yano Barry L. , Hayden David W. , Johnson Kenneth H.
Published: February 2025

Secondary systemic amyloidosis was histochemically documented in the pancreatic islets of a 13-year-old, male, nondiabetic domestic cat. Amyloid was deposited around blood vessels in the islets, but was not restricted to this site. The potassium permanganate/Congo red staining reaction was used to confirm the secondary systemic nature of the amyloid in the pancreatic islets and other tissues of this cat.
Modulation of early cellular events in wound healing in mice
Authors: Kenyon Alan J. , Michaels Edwin B.
Published: February 2025

Wound healing experiments were conducted in random-bred Swiss mice to determine the effect on antimicrobial surfactants and macrophage stimulators on wound measurements, histologic repair, and wound breaking strengths. In selection of mice, Sendai virus antibody-positive mice healed more slowly than did mice with no detectable titer to Sendai virus. Studies were conducted with Sendai virus-free mice that had C31G (an antimicrobial surfactant), alkyl amine oxide, zymosan, glucan, or phosphate-buffered isotonic saline solution instilled into full-thickness incised wounds. The early events in the repair process indicated a greater degree of inflammatory response comprised mainly of polymorphonuclear leukocytes with subsequent large numbers of monocytes in C31G and alkyl amine oxide-treated wounds. Although zymosan did not induce as large a number of monocytes, the degree of fibroplasia was as great as in wounds in which numbers were higher. The effect of zymosan could be blocked by the addition of N-α-p-tosyl-l-lysine chloromethyl ketone to wounds. Wound breaking strength 3 days after surgery was greatest for glucan-treated mice (134 ± 37 g) whereas that in C31G-treated mice (77 ± 31 g) was less than that of the controls (92 ± 37 g). By day 7, there was no significant difference in breaking strength between control and glucan-treated wounds; however, C31G-treated wounds remained substantially weaker than control wounds.
Serum amylase and lipase activities in dogs with chronic primary renal failure
Authors: Polzin David J. , Osborne Carl A. , Stevens Jerry B. , Hayden David W.
Published: February 2025

Serum amylase and lipase activities and their relationship to renal function and lesions of the pancreas were studied in 18 dogs with surgically induced chronic renal failure and 41 dogs with spontaneously occurring primary renal failure. In addition, the influence of a canine maintenance diet and 2 modified protein diets on serum amylase and lipase activities was examined in the dogs with experimental renal failure. After surgical induction of renal failure, a 2.5-fold increase in mean serum amylase activity and a 3-fold increase in mean serum lipase activity were observed.

In dogs with spontaneously occurring primary renal failure, mean serum amylase activity was increased 2.5 times normal, and mean serum lipase activity was increased 4 times normal. A relationship was not found among increments in serum amylase and lipase activities and inulin clearance rate, serum creatinine concentration, or urea nitrogen concentration in dogs with experimental or spontaneous chronic renal failure. A relationship between serum amylase activity and serum lipase activity in dogs with experimental or spontaneous chronic renal failure was not detected. Diet did not appear to influence serum amylase or lipase activities.

Except for reduction of pancreatic zymogen granulation, definitive microscopic pancreatic lesions were not observed.

Of the dogs with spontaneously occurring renal failure, 37% had increased serum amylase and lipase activities, 22% had increased serum amylase activity and normal serum lipase activity, 12% had increased serum lipase activity and normal serum amylase activity, and 29% had normal serum amylase and lipase activities.

It appears that hyperamylasemia and hyperlipasemia are not reliable indices of concurrent acute pancreatitis in dogs with chronic primary renal failure.
Characterization of antigens from mycoplasmas of animal origin
Authors: Boothby J. T. , Jasper D. E. , Rollins M. H.
Published: February 2025

Alcholeplasma laidlawii, Mycoplasma gallisepticum, M mycoides subsp mycoides, M agalactiae, M bovirhinis, mycoplasmal strain ST-6, and culture medium were compared with M bovis by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, enzyme-linked immunosorbent assay (elisa), and gel electrophoresis-derived elisa. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis indicated there were areas of homology and areas of heterology among the species tested. Sera from rabbits hyperimmunized with the mycoplasma organisms and noninoculated culture medium demonstrated elisa reactivity with M bovis antigens immobilized on polystyrene. Absorption of the serum from a rabbit hyperimmunized with M bovis reduced 65.9% of its reactivity with culture medium, 29.7% to 32.7% of its reactivity with the heterologous species, and 21.1% of its reactivity with the homologous species. Gel electrophoresis-derived elisa performed on immobilized M bovis antigens separated by molecular weight, using sera from rabbits hyperimmunized with the mycoplasmal species under study and noninoculated culture medium revealed antigenic components which are shared among species or with the culture medium and several components which may be unique to M bovis.
Effect of the estrogenic mycotoxin zearalenone on reproductive potential in the boar
Authors: Ruhr Lawrence P. , Osweiler Gary D. , Foley C. W.
Published: February 2025

SUMMARY AND CONCLUSIONS

Thirteen mature Yorkshire boars were fed graded levels of the estrogenic mycotoxin zearalenone for 8 weeks, the equivalent of 0,2,20, and 200 mg of zearalenone/kg of complete ration (0, 2, 20, and 200 ppm). Weekly semen collections and evaluations were initiated 2 weeks before treatment began and were continued for 2 weeks after treatment ceased. Testicular size and libido were evaluated. Semen evaluation included the following: presperm, sperm rich, and postsperm fraction volumes; gel volume and percentage of total volume; duration of ejaculation; and total spermatozoa per ejaculate and sperm concentration. Sperm motility, oxygen consumption by washed spermatozoa, and the percentage of primary morphologic abnormalities were evaluated. Plasma testosterone and estradiol-17β concentrations were determined.

Using analysis of variance, treatment-related effects in which any treatment differed significantly from the control were not demonstrated. Seemingly, zearalenone at amounts greater than normally encountered in field exposures [200 mg/kg of feed (200 ppm)] for 8 weeks did not affect adversely the reproductive potential of mature boars.
Invasion of avian encephalomyelitis virus from the gastrointestinal tract to the central nervous system in young chickens
Authors: Miyamae T.
Published: February 2025

Invasion sites of avian encephalomyelitis virus in the internal organs of orally infected chicks were determined by the immunofluorescent method. The invasion began when the epithelium tunica mucosae of the duodenum (together with the proventriculus, jejunum, or cecum in certain birds killed at postinoculation day 1) became test-positive. Viremia persisted for more than 5 days in the early stage of infection, then the pancreas was rapidly infected, followed by the liver, kidney, and spleen. Subsequently, the virus spread to the cns. Rapid infection of the duodenum and pancreas was clearly observable.
Acetone-treated agglutinin against Yersinia pseudotuberculosis in free-living rats
Authors: Kaneko Ken-ichi , Hashimoto Nobuo
Published: February 2025

Retrospective investigation was done on Yersinia pseudotuberculosis infection in barn rat populations living in an Yersinia endemic area and in zoo rat populations living in a nonendemic area. The OH agglutinins against Y pseudotuberculosis were normally distributed within both populations. Most of the OH agglutinin titers and many O agglutinin titers were reduced by treatment of sera with acetone. Sera with O and OH agglutinin titers were assigned to 2 groups, one with a titer < 1:8 and the other with a titer of ≥ 1:8.

Rats harboring the organism did not possess O or OH agglutinin titers > 1:8 in acetone-treated sera. In most nontreated sera, OH agglutinin titers were higher than were the O agglutinin titers. However, in most acetone-treated sera, O agglutinin titers were equivalent to OH agglutinin titers. Differences by region and age were observed in acetone-treated O agglutinin titers of ≥ 1:8 against Y pseudotuberculosis. Therefore, it is recommended that to detect antibody against Y pseudotuberculosis in rats, sera should be treated with acetone before the test and O antigen should be used.
Thermographic evaluation of horses with podotrochlosis
Authors: Turner T. A. , Fessler J. F. , Lamp M. , Pearce J. A. , Geddes L. A.
Published: February 2025

The distal forelimbs of 10 clinically normal horses with hair clipped on 1 limb were thermographically scanned before and after exercise. The thermal patterns, temperature distribution, and temperature changes after exercise were determined and compared with those of 8 horses with podotrochlosis. Clipping the hair did not cause changes in the thermal patterns, but the clipped limbs were warmer than the unclipped limbs. The temperature of the limbs of horses with podotrochlosis did not increase as much after exercise as did the limbs of normal horses. The failure of skin temperature increase correlated with the radiographic evidence of enlarged vascular foramina in the navicular bone. Because the failure to increase skin temperature after exercise is the result of low blood flow, the enlarged vascular foramen can be related to a state of low blood flow.
Antigenicity of bovine parvovirus in fetal infections
Authors: Hayder H A. , Storz J. , Young S.
Published: February 2025

The humoral immune response of bovine fetuses to bovine parvovirus (bpv) infection during the 2nd and 3rd trimesters was studied by the single radial immunodiffusion, hemagglutination-inhibition (hi), indirect immunofluorescence (ifa), microneutralization (mn), plaque-neutralization, and double immunodiffusion (did) tests. Serum samples collected from 23 bpv-inoculated and several control fetuses were tested. The immunoglobulin (Ig) M concentration reached 355 mg/100 ml at 10 days after fetal inoculations were done and then decreased. The IgG concentration increased 10 days after inoculation and was maximal 142 days later. A correlation between Ig concentrations and antibodies reacting in the hi, ifa, mn, DID, and plaque-neutralization tests existed in all samples. Neutralizing and hi antibodies were detected 10 days after fetal inoculations. The highest mn titer of 4,096 was detected in a fetus 10 days after the inoculation done during the 3rd trimester. Six serum samples were positive in the ifa test. These samples, collected 10 to 60 days after fetuses were inoculated, had IgG concentrations of 615 mg/100 ml or higher, and had titers of 16 to 64.

Treatment of bpv with carbonate-bicarbonate buffer (pH 10.5) disrupted the virus and liberated antigens reacting in the did test. Electron microscopic examination of the negatively stained antigen preparation revealed loss of structural integrity of the viral particles. This suspension of disrupted bpv was reactive with some of the fetal serum samples in the did test, inducing 1 or 2 precipitin lines.
Neutrophil movement in selected canine skin diseases
Authors: Latimer Kenneth S. , Prasse Keith W. , Mahaffey Edward A. , Dawe Donald L. , Lorenz Michael D. , Duncan J. Robert
Published: February 2025

Neutrophilic movement was studied in dogs with atopy, 3 bacterial pyoderma syndromes, flea allergy dermatitis, and generalized demodicosis. Random neutrophil movement was decreased in generalized demodicosis, and this deficit correlated with the extent of body surface skin lesions. Neutrophilic chemotactic movement was decreased in 2 bacterial pyoderma syndromes: bacterial pyoderma, and staphyloccal pyoderma. Although serum samples from diseased dogs showed no significant differences in chemoattractive qualities from normal pooled canine serum, control canine neutrophils incubated in demodectic dog serum showed decreased chemotactic responsiveness. It was postulated that demodectic dog serum had an inhibitor or deactivator of neutrophil chemotaxis.
Electrophysiologic studies of the cutaneous nerves of the head of the dog
Authors: Whalen L. R. , Kitchell R. L.
Published: February 2025

The cutaneous nerves of the head of the dog were investigated in 16 barbiturate-anesthetized dogs. The electrophysiologic demonstration of afferent impulses in a given cutaneous nerve to the movement of hairs within an area of skin was used to delineate the nerve's cutaneous area (ca) of innervation. In this manner, the ca for the cutaneous branches of the trigeminal nerve, the facial nerve, and the 2nd, 3rd, and 4th cervical nerves were determined. The ca of adjacent cutaneous nerves were found to overlap extensively. The portion of a nerve's ca which was solely innervated by it was termed the autonomous zone. Most of the ca of the head was innervated by branches of the trigeminal nerve. The internal auricular branches of the facial nerve innervated the majority of the concave surface of the pinna. The branches of the 2nd cervical nerve supplied a large ca which extended from the caudal intermandibular space to the dorsal midline and apex of the pinna. The ca of the branches of the 3rd and 4th cervical nerves occupied much of the cervical area cranial to the scapula and caudal to the hyoid apparatus. A ca was not found for the 1st cervical nerve.
Pathogenesis of Trypanosoma brucei infection in deer mice (Peromyscus maniculatus): Light and electron microscopic studies on erythrocyte pathologic changes and phagocytosis
Authors: Anosa Victor O. , Kaneko J. J.
Published: February 2025

Light microscopic and scanning and transmission electron microscopic studies demonstrated that Trypanosoma brucei EATRO 110 produced several alterations in rbc structure including microspherocytes, schistocytosis, vacuolation, doughnut-cell formation, and keratocytosis. Mature rbc and reticulocytes were constantly observed to adhere firmly to trypanosomes in heart blood and in blood vessels of the testes, heart, liver, and kidney, as well as in the sinuses and pulp cords of the spleen. Adhesion of rbc to trypanosomes was also observed by light microscopy in thin blood films. Except for a few platelets that adhered to trypanosomes, other blood cells were not involved. Minute pores were sometimes observed on the rbc membrane at the point of adhesion to the trypanosome, but effects were not seen on the parasite. Erythrophagocytosis was marked in the spleen and to a lesser extent in the liver; mature rbc, as well as reticulocytes, were engulfed. Erythrophagocytosis was presumed to arise from the mechanical injury to rbc, the damage caused by the adhesion phenomenon and the hyperactivity of the enormously enlarged spleen.
Estrogen-induced bone marrow depression in ferrets
Authors: Bernard Susan L. , Leathers Charles W. , Brobst Duane F. , Gorham John R.
Published: February 2025

The administration of estrogen-induced severe bone marrow depression in 9 of 12 ferrets, independent of sex (male, female) or ovariohysterectomy. Resultant pancytopenia was manifested by subcutaneous petechiae, melena, hematomyelia, pale mucous membranes, pale bone marrow, centrilobular hepatic degeneration, hydrometra, and pyometra. These findings are compatible with the naturally occurring estrus-associated anemia seen in female ferrets.1
Antibiotic activity against intraleukocytic Staphylococcus aureus in vitro and in experimental mastitis in mice
Authors: Craven V. , Anderson J. C.
Published: February 2025

The activities of a range of antibiotics on Staphylococcus aureus organisms that survive within bovine neutrophils in vitro were studied in mice. Cloxacillin, floxacillin, and cephradine failed to kill intracellular staphylococci but increased the organisms' sensitivity to killing by lysostaphin after neutrophil disruption. Fusidate and clindamycin caused an apparent small reduction in viable intraleukocytic S aureus, whereas novobiocin did not demonstrate intracellular activity. Substantial intracellular bactericidal effects were shown in vitro by rifampin and rifamycin SV, even at concentrations in slight excess of the minimum inhibitory concentration. In a mouse model of chronic mastitis, intramammary therapy with rifampin was more effective in reducing viable S aureus in infected glands than was therapy with rifamycin SV.
Evaluation of the fluorescent antibody test for diagnosis of paratuberculosis
Authors: Abbas Babiker , Riemann Hans , Behymer Darrell E.
Published: February 2025

Results of indirect fluorescent-antibody microscopy did not differ significantly from complement-fixation test results in diagnosing paratuberculosis (Johne's disease) in cattle. Neither test had acceptable sensitivity or specificity for detecting subclinical cases.
Distribution of oxytetracycline in genital tract tissues of postpartum cows given the drug by intravenous and intrauterine routes
Authors: Bretzlaff K. N. , Ott R. S. , Koritz G. D. , Bevill R. F. , Gustafsson B. K. , Davis L. E.
Published: February 2025

Oxytetracycline (otc) was administered by constant iv infusion to 3 healthy postpartum cows at rates predicted to approach a steady-state plasma concentration of 5 μg/ml. After 8 hours of constant iv infusion, genital tissues were surgically removed. The mean plasma-to-tissue ratios of concentrations of otc were 0.95, 1.33, 1.88, and 1.04 (2 cows only) for caruncles, endometrium, uterine wall, and ovaries, respectively. Differences between the ratios of any 2 of the uterine tissues were statistically significant (P < 0.05).

Intrauterine (iu) infusions of 5.5 mg of otc/kg were administered to 3 healthy postpartum cows and 3 postpartum cows with metritis. The mean values of the fraction of the drug absorbed from the uteri of cows given iu infusions of otc were 0.50 and 0.23 for healthy postpartum cows and postpartum cows with metritis, respectively. Concentrations of otc were high in the caruncles and endometrium of all cows at 24 hours after iu infusions of the drug. Concentrations in the plasma, uterine wall, and ovaries were low, with mean concentrations of otc in these tissues in postpartum cows with metritis being lower than those in the same tissues of healthy postpartum cows.

Computer-simulated genital tissue concentrations of otc after twice daily iv doses of 11 mg/kg indicated that this dosage regimen would provide postpartum uterine tissue concentrations > 5 μg/g throughout the dosage interval in all tissues, except the uterine wall.
Aspirin and prednisolone modification of postadulticide pulmonary arterial disease in heartworm-infected dogs: Arteriographic study
Authors: Rawlings C. A. , Keith J. C. , Losonsky J. M. , Lewis R. E. , McCall J. W.
Published: February 2025

Prednisolone and aspirin were used after thiacetarsamide treatment of 3 groups of 6 dogs infected with 9 heartworms each. Pulmonary blood flow and anatomic features were evaluated by arteriography before transplantation of the heartworms and 4 weeks after adulticide treatment. None of the 18 dogs had clinical signs of disease during the study. Arteriography showed that most dogs had intraluminal-filling defects. Altered flow was most common in the 2 caudal lobar and accessory lobar arteries with only 14 of these 54 arteries appearing to be normal. Thirty-two arteries had decreased flow with total obstruction or intraluminal filling defects, and 6 had decreased flow without obvious filling defects. Total obstruction was produced by a combination of obliterative tunica intimal proliferation and thromboemboli containing dead heartworms. The filling defects were live or dead heartworms, linear projections of tunica intimal proliferation, or thromboemboli. Dogs treated with aspirin (10 mg/kg of body weight daily starting on the first thiacetarsamide treatment day and continuing for 4 weeks) appeared to have better perfusion than did the control or prednisolone-treated dogs. Caudal lobar and accessory lobar flow was markedly decreased in the prednisolone-treated dogs (1.0 mg/kg daily starting on the first thiace-tarsamide day and continuing for 4 weeks), and 6 of 7 dogs had total obstruction of the right caudal lobar artery. After thiacetarsamide treatment, the main pulmonary artery and lobar arteries were wider than before heartworm transplantation. Increases in size of these arteries were not present in the aspirin-treated dogs and only the main and left pulmonary arteries were increased in the control dogs. Aspirin appeared to improve and prednisolone appeared to worsen the pulmonary artery perfusion 4 weeks after thiacetarsamide treatment.
Parasites in Kentucky Thoroughbreds at necropsy: Emphasis on stomach worms and tapeworms
Authors: Lyons E. T. , Tolliver S. C. , Drudge J. H. , Swerczek T. W. , Crowe M. W.
Published: February 2025

A total of 363 Thoroughbreds (62 males, 292 females, and 9 geldings), 1 to 26 years of age, were examined at necropsy for internal parasites for about a 12-month period from February 1981 through February 1982. Emphasis was on examining the stomach for nematodes and the small intestine and cecum for tapeworms. Parasites recovered from the stomach and infection rates were: Habronema spp—immature (24%), H muscae—adult (38%), Draschia megastoma—immature (13%), D megastoma—adult (62%), and Trichostrongylus axei—adult (4%); lesions caused by D megastoma were found upon gross observation in 58% of the stomachs. The tapeworm, Anoplocephala perfoliata, was recovered from 54% of the horses; A magna was not found. There was no obvious difference in infection rates of the stomach worms and tapeworms according to age or sex of the horses. Seasonal differences were apparent only for immature Habronema spp and immature D megastoma for which infection rates began increasing in June, peaking in October, and declining thereafter. Presence of 4 additional species of parasites was recorded, but only a cursory examination was made for them. These were the large strongyles, Strongylus vulgaris, S edentatus, and S equinus, from the cecum and a filariid, Setaria spp (probably S equina), from the abdominal cavity, for which recovery rates from the horses were 8%, 8%, 1%, and 7%, respectively.
Isolation and partial characterization of a calicivirus from calves
Authors: Smith Alvin W. , Mattson Donald E. , Skilling Douglas E. , Schmitz John A.
Published: February 2025

A calicivirus was isolated from 3 dairy calves in a herd with persistent calf respiratory tract problems. This virus, named Tillamook calicivirus, was not neutralized by 18 different calicivirus-typing serums available. The agent caused only minimal lesions in 2 experimentally exposed calves, but did establish a persistent infection with virus shedding for 45 days, after which time the experiment was terminated. Experimentally exposed swine developed clinical vesicular lesions. The possible origins, disease potential, and relationships to the exotic animal disease agent, vesicular exanthema of swine are discussed for this first calicivirus isolate of bovine origin.
Enzyme-linked immunosorbent assay for the detection of antibodies to Leptospira interrogans serovars hardjo and pomona in cattle
Authors: Thiermann A. B. , Garrett L. A.
Published: February 2025

An enzyme-linked immunosorbent assay (elisa), which used the phenol phase of a hot phenol-water extraction as antigen, and the microscopic agglutination test were compared for the detection of antibodies to Leptospira interrogans serovars hardjo and pomona in cattle. Among serum samples from vaccinated cattle, the elisa (using antiglobulin) was positive to 64% with hardjo antigen and to 78% with pomona antigen, whereas the microscopic agglutination test was positive to only 18% with hardjo and 23% with pomona. There were no elisa reactions observed among known negative-control samples. The elisa, using antiglobulin conjugate, was overall a more sensitive technique for the detection of leptospiral antibodies in cattle.
Development of a semiautomated microassay for bovine immunoglobulin E: Definition and standardization
Authors: Gershwin Laurel J. , Dygert Bradley S.
Published: February 2025

Although the serum immunoglobulin (Ig) E concentration is a critical and valuable measurement in parasitic infections and allergic diseases, little has been reported on it in cattle. We have developed an enzyme-linked immunosorbent assay to measure serum concentrations of bovine IgE. This assay was developed and standardized, using the statistical guidelines of the Bureau of Biological Standardization of National Institutes of Health. A reference serum used to standardize results was assigned a value of 100 IgE U/ml. Absorbance values for test samples were converted into IgE units by comparison with a standard curve, generated by dilutions of this reference serum. Serum samples from 160 adult cows and calves had a geometric mean of 17.8 IgE U/ml. The IgE values were higher in calves from parasite-infested pastures than in parasite-free calves and adult cows. This assay is the first procedure appropriate for multiautomated analysis of IgE in cattle.
Comparative efficacy of an experimental S45/20 bacterin and a reduced dose of strain 19 vaccine against bovine brucellosis
Authors: Woodard L. F. , Jasman R. L.
Published: February 2025

Yearling beef heifers were vaccinated with 2 doses of an experimental Brucella abortus S45/20 bacterin or a reduced dose of strain 19 (S19) vaccine, or were used as nonvaccinated controls. None of the vaccinated heifers was positive by the acidified plate, Rivanol, complement-fixation, or card tests 5 months after inoculation. Sixteen of 21 heifers given S45/20 bacterin with trehalose dimycolate adjuvant had delayed hypersensitivity when skin was tested 7 months after initial vaccination, whereas none of the S19 vaccinates or controls was reactive.

After natural breeding, pregnant heifers were challenge exposed at 3.5 to 5 months of gestation with 2.5 × 107 viable B abortus S2308 organisms in the conjunctival sac. Abortions occurred as follows: 16/19 (84.2%) of heifers given S45/20 bacterin, 6/12 (50.0%) of heifers vaccinated with S19, and 17/18 (94.4%) of the nonvaccinated controls. Of the 10 heifers that calved normally, only 3 (1 in each group) were seropositive. A correlation was not seen between skin hypersensitivity and acquired resistance. Possible reasons for the poor protection with a reduced dose of S19 vaccine and the failure of S45/20 bacterin to enhance cellular resistance are discussed.
Furazolidone-induced congestive cardiomyopathy in ducklings: Myocardial ultrastructural alterations
Authors: Van Vleet John F. , Ferrans Victor J.
Published: February 2025

Newly hatched male White Pekin ducklings were fed furazolidone (fz) at dosage of 750 mg/kg of feed for 4 weeks. Selected ducklings with advanced lesions of fz-induced congestive cardiomyopathy were used for ultrastructural study of the myocardial alterations. Semithin sections of plastic-embedded blocks of myocardium from these dilated hearts revealed diffuse myocytolysis, characterized by pale sarcoplasm and lack of cross-striations in affected myocytes. Evidence of myocardial necrosis, inflammation, or fibrosis was not observed. Ultrastructural study revealed that the principal alteration in cardiac muscle cells was diffuse myofibrillar lysis. The sarcoplasm of affected myocytes had scattered masses of free thick and thin myofilaments, clumps of Z-band material, and accumulations of cytoskeletal filaments. Numerous polyribosomes were present in the areas of lysis of contractile material, as were other normal-appearing organelles. Myofibrillar lysis may have resulted from fz-induced decreased synthesis, increased degradation, or disaggregation of contractile proteins. Ducklings with fz-induced congestive cardiomyopathy offer an attractive model for studies of the biochemical and ultrastructural alterations of myofibrillar lysis and drug-induced cardiac failure.
Comparative pharmacokinetics of antibiotics in newborn calves: Chloramphenicol, lincomycin, and tylosin
Authors: Burrows G. E. , Barto P. B. , Martin B. , Tripp M. L.
Published: February 2025

The pharmacokinetics of 3 antibiotics—chloramphenicol, lincomycin, and tylosin—were determined in newborn calves. The kinetic determinations, using 2-compartment open models, were made at increasing ages from 1 day to 42 days and compared with those made from 9-month-old calves. Although all 3 antibiotics require a degree of hepatic metabolism, there were marked differences in the development of elimination processes for the individual drugs. Elimination of tylosin, which was slow in the calves at birth, increased rapidly and was equal to that in older calves by the end of 1 week. Lincomycin elimination was not markedly reduced in calves at birth. Chloramphenicol elimination was slow in calves at birth and only by 4 to 6 weeks attained the rate found in older calves. Dosage adjustments would not be required for the antibiotics tylosin or lincomycin when given to newborn calves, but may be necessary for chloramphenicol given to calves before they are 4 to 6 weeks old.
Controlled tests with fenbendazole in equids: Special interest on activity of multiple doses against natural infections of migrating stages of strongyles
Authors: Lyons E. T. , Drudge J. H. , Tolliver S. C.
Published: February 2025

Three controlled tests (experiments A, B, and C) were conducted in equids for evaluation of activity of fenbendazole paste formulation, administered intraorally, against naturally acquired infections of internal parasites, particularly Strongylus vulgaris in the cranial mesenteric artery (experiments A and B), Strongylus edentatus in the ventral abdominal wall (all 3 experiments), and small strongyles in the mucosa of the cecum, ventral colon, and dorsal colon (all 3 experiments). Dose rates for fenbendazole were 7.5 mg/kg of body weight (experiment A) or 10 mg/kg (experiments B and C) given once daily for 5 consecutive days. The type and number of equids in the tests were as follows: experiment A—4 Quarter Horse yearlings, 2 treated and 2 nontreated; experiment B—8 horses mostly of mixed breeding, about 5 to 8 months old, 4 treated and 4 nontreated; and experiment C—3 Shetland-type pony yearlings, 2 treated and 1 nontreated. Time of necropsy relative to last day (5th day) of treatment was: experiment A—27 or 28 days for treated and 16 or 19 days for nontreated horses; experiment B—35, 36, or 37 days for treated and nontreated horses (at least 1 of each killed each day); and experiment C—34 days for treated and nontreated ponies.

Activities against parenteral stages of S vulgaris were moderately good at the 7.5 mg/kg dosage and excellent at the 10 mg/kg dose rate. For S edentatus, activity was excellent at the 2 dose rates. Removal of small strongyles from the mucosa was generally poor in experiment A and B, but excellent in experiment C.

Adult S vulgaris (present in experiments A and B) and adult S edentatus (present in experiments A and C) were efficaciously removed from the large intestine. A few specimens of S vulgaris, present in some treated animals, may have emerged from nodules in the mucosa between the time of treatment and necropsy, indicating lack or incomplete killing of stages of S vulgaris in nodules in the intestinal wall.

In experiment B, anthelmintic activity was evaluated also against certain parasites other than strongyles; removal activities against Draschia megastoma (mature), Parascaris equorum (immature and mature), and Oxyuris equi (mature) were excellent. For 2 other mature parasites (Thelazia lacrymalis and Habronema muscae), which were present in numbers possibly too low for proper drug evaluation, activity by fenbendazole was also excellent.

Toxicosis was not evident in any of the treated equids.
Histoquantitative effects of orchiectomy with and without testosterone enanthate treatment on the bovine epididymis
Authors: Goyal H. O.
Published: February 2025

The histoquantitative effects of orchiectomy with and without testosterone enanthate treatment on the bovine epididymis as relates to epithelial height, luminal diameter, and thickness of smooth muscle wall were determined. With androgen deprivation (induced by orchiectomy), epithelial heights in epididymal regions I, II, III, IV, V, and VI were reduced to 25%, 47%, 46%, 39%, 39%, and 79% of the controls respectively. In the orchiectomized bulls treated with testosterone, the epithelial height in region I increased to only 29% of the controls and the heights reached 58% to 67% of the controls in regions II to V and as much as 111% in region VI. These data indicate that circulating testosterone does not have an important role in maintaining the epithelial height in region I, whereas it seems to be solely responsible for its maintenance in region VI. The epithelial heights in regions, II, III, IV, and V are probably dependent on both circulating and luminal androgens.

Similar to the epithelial height, the luminal diameter in all regions was markedly reduced by orchiectomy; however, testosterone treatment failed to restore the diameter to the control levels.

In contrast to the epithelial height and luminal diameter, the thickness of the smooth muscle wall in all regions was significantly increased following orchiectomy. Although it decreased in the orchiectomized bulls treated with testosterone, it was still thicker than that of controls. The relative significance of luminal and circulating androgens in maintaining the structure and function of the epididymal epithelium is discussed.
Halothane potency in pigs (Sus scrofa)
Authors: Tranquilli W. J. , Thurmon J. C. , Benson G. J. , Steffey E. P
Published: February 2025

The minimum alveolar anesthetic concentration for halothane in oxygen which just prevented gross purposeful movement to a tail clamp stimulus averaged 0.91 ± 0.03 (sem) volumes % in 12 pigs (Sus scrofa). This value compares favorably with halothane minimum alveolar values reported for other nonhuman mammalian species.
Toxicity investigation of fenbendazole, an anthelmintic of swine
Authors: Hayes R. H. , Oehme F. W. , Leipold H.
Published: February 2025

The toxicity of fenbendazole, an anthelmintic for use in swine, was tested by feeding 8 growing pigs 2,000 mg of fenbendazole/kg of body weight daily for 14 days. A transient leukopenia developed on day 6, but values returned to base line on day 18, 4 days after discontinuation of dosing. Sorbitol dehydrogenase values were significantly (P < 0.05) increased from day 4 and returned to base line on day 20. Marked gross or histopathologic lesions were not found.
Safety of fenbendazole in swine
Authors: Hayes R. H. , Oehme F. W. , Leipold H.
Published: February 2025

The safety of fenbendazole, an anthelmintic for use in swine, was tested by feeding 0, 25, 75, or 125 mg of fenbendazole/kg of body weight for 5 days. A dose-related transient leukopenia developed on day 7, but values returned to base line on day 15. In the groups fed 75 or 125 mg, sorbitol dehydrogenase activity increased on day 3 but returned to base line on day 10. Significant gross or histopathologic lesions were not found.