bluuebunny/crossref_metadata_2025 huggingface dataset:
Haemophilus somnus: Investigations of its potential role in bovine mastitis
Authors: Hazlett Murray J. , Little Peter B. , Barnum Donald A. , Maxie M. Grant , Leslie Kenneth E. , Miller Richard B.
Published: February 2025

Mammary glands of 6 lactating Holstein cows were inoculated with Haemophilus somnus strain 43826. Three cows developed chronic mastitis and shed bacteria for up to 1 year. Three cows developed acute gangrenous mastitis, with evidence of bacteremia and endotoxemia. Cows with gangrenous mastitis had lower somatic cell counts early after inoculation in affected quarter secretions compared with those in cows that developed chronic mastitis. Cows with gangrenous mastitis developed hypocalcemia, hypoalbuminemia, azotemia, hyperbilirubinemia, mildly increased serum aspartate aminotransferase and creatine kinase activity, and a marked neutropenia with a degenerative left shift. Histopathologic examination of gangrenous quarters revealed edema, necrosis, and vascular thrombosis with few inflammatory cells. A limited survey failed to recover H somnus from dairy cows with clinical mastitis or from mammary secretions from 41 beef cattle at an abattoir.
Switch hair as an indicator of magnesium and copper status of beef cows
Authors: Fisher D. D. , Wilson L. L. , Leach R. M. , Scholz R. W.
Published: February 2025

Samples of switch hair, blood, and urine were obtained periodically over 5.5 months from 11 Angus and 13 Angus-Charolais cows grazing either all-grass or grass-legume swards. Liver samples were obtained at the end of the study. Hair growth rate and mineral concentrations in switch hair (magnesium [Mg], copper [Cu]), blood serum (Mg, Cu), urine (Mg), and liver (Cu) were determined. Significant (P < 0.05) hair-growth rate differences were observed among sampling periods (daily X = 0.58 ± 0.01 mm), Angus black-pigmented switch hair contained more (P < 0.001) Mg than did the light-pigmented Angus-Charolais hair. The effect of season was observed on hair Mg and Cu and on serum Mg (P < 0.01). Serum and hair Mg concentration correlated in both breed groups after removal of individual cow treatment effects (Angus: r = 0.58, P < 0.001, n = 64; Angus-Charolais: r = 0.46, P < 0.001, n = 76). Likewise, urine Mg and hair Mg concentrations correlated (Angus: r = 0.35, P < 0.05, n - 53; Angus-Charolais; r = 0.26, P < 0.05, n = 63). Sward type had a pronounced effect on serum and urine Mg concentrations and a slight effect on hair Mg concentrations (P < 0.10) only during midsummer, Cattle with switch hair Mg values < 25 to 30 mg (light pigmentation) and 100 to 125 mg (black pigmentation)/kg of dry matter (dm) may be hypomagnesemic. Copper concentrations in the end segment of hair plucked in early spring correlated (r = 0.46, P < 0.05, n = 23) with Cu concentrations in serum obtained in the spring. The corresponding correlation of autumnal hair and serum Cu concentration was 0.54 (P < 0.01; n = 23). Copper concentrations in autumnal hair also correlated with liver Cu concentrations (r = 0.50, P < 0.05, n = 19). Overall mean serum Cu concentrations and individual Cu concentrations (autumnal serum) correlated with liver Cu concentrations (r = 0.48, P < 0.05, n = 20 and r = 0.45, P < 0.05, n = 20, respectively). Six cows with a mean liver Cu concentration of 28.5 ± 5.7 mg/kg of dm, indicating marginal deficiency, had serum and hair Cu concentrations of 0.66 ± 0.04 mg/L and 8.7 ± 0.4 mg/kg of dm, respectively. The end segment of hair (obtained on the previous sampling date) and the corresponding intermediate segment correlated 0.51 for Mg (P < 0.001, n = 89,) and 0.36 for Cu (P < 0.001, n = 79). Over 127 days (using paired-hair segments obtained on different dates), Mg concentrations increased near-linearly with time as a result of environmental contamination. Copper concentration did not increase noticeably until the 127th day.
Effectiveness of a slow-release, morantel tartrate anthelmintic bolus for controlling parasitic gastroenteritis in replacement dairy heifers
Authors: Gibbs H. C. , Kitsos A.
Published: February 2025

Two experiments were done to evaluate the effectiveness of a slow-release, morantel tartrate, anthelmintic bolus for controlling parasitic gastroenteritis in replacement dairy heifers. In experiment 1, good control of nematode contamination of pasture was indicated by lower worm burdens in tracer calves that grazed with 15 heifers treated orally with a single bolus and by significantly decreased numbers of nematode eggs in the feces of the 15 treated heifers, as compared with numbers of eggs in the feces of 15 nontreated control calves. Significant differences in weight gain were not seen between treated and nontreated heifers, probably due to low amounts of larval exposure, the small number of heifers evaluated, and parasitic resistance in the heifers, which may have developed as a result of prestudy exposure to contaminated pasture.

In experiment 2, done 1 year after the 1st experiment, using the same pastures that were used in experiment 1, young heifers were used. Many of the heifers were parasite naive at the beginning of the experiment (ie, nematode eggs were not found before the experiment). Treatment with the bolus was effective in controlling parasitic gastroenteritis in the heifers and in controlling nematode contamination of pasture. Compared with nontreated heifers, treated heifers had significantly higher cumulative weight gains, a significant decrease in plasma pepsinogen concentrations, and a significant decrease in worm egg excretion. The number of worms acquired by tracer calves that were grazed with treated heifers was significantly less than for tracer calves that were grazed with nontreated heifers.
Serotype-specific resistance to nasal colonization by Pasteurella haemolytica in cattle
Authors: Frank Glynn H.
Published: February 2025

Vaccination of calves with a Pasteurella haemolytica serotype 1 antigen preparation elicited a serotype-specific inhibition of nasal colonization by P haemolytica under field conditions. Inhibition was evidenced by a low frequency of nasal colonizations and by relatively few P haemolytica serotype 1 organisms isolated from vaccinated calves. The study comprised 3 field trials, each on a separate year, and included 480 calves.
Effect of antibiotics and vehicles on bovine mammary polymorphonuclear leukocyte morphologic features, viability, and phagocytic activity in vitro
Authors: Nickerson Stephen C. , Paape Max J. , Dulin Ann M.
Published: February 2025

Effects of antibiotics and antibiotic vehicles on polymorphonuclear leukocytes (pmnl) isolated from bovine mammary glands were studied in vitro. Amikacin, dicloxacillin, erythromycin, gentamicin, lincomycin, nitrofurantoin, novobiocin-penicillin, polymyxin B, rifampin, tetracycline, or tiamulin was added to culture medium at 1 mg/ml and chloramphenicol was added at 4 mg/ml. Drug concentrations were equivalent to those detected in milk immediately after injection into the mammary gland. Vehicles included mineral oil and peanut oil, each at a dilution of 1:100 in culture medium. The pmnl morphologic features, viability, and phagocytic activity were evaluated.

In comparison with the phosphate-buffered saline solution (pbss) control, significant (P < 0.05) alterations in normal cell morphologic features were observed in pmnl cultured with tetracycline, nitrofurantoin, erythromycin, polymyxin B, rifampin, novobiocin-penicillin, chloramphenicol, tiamulin, or peanut oil. Viabilities of pmnl cultured with chloramphenicol, novobiocin-penicillin, or tiamulin were significantly (P < 0.05) reduced when compared with those of pbss controls. Addition of Staphylococcus aureus to culture medium enhanced morphologic alterations and reduced viabilities of pmnl. Phagocytosis of S aureus by pmnl was significantly (P < 0.05) depressed in medium containing novobiocin-penicillin, amikacin, rifampin, chloramphenicol, tiamulin, or peanut oil in comparison with that of pmnl incubated in pbss.
Kidney graft survival in transfused and nontransfused sibling Beagle dogs
Authors: Finco Delmar R. , Rawlings Clarence A. , Barsanti Jeanne A. , Crowell Wayne A.
Published: February 2025

In 6 pairs of sibling Beagle dogs, 1 kidney was exchanged between pairs, and contralateral nephrectomy was done. Previously, one dog of each pair was given blood transfusions from the donor of its allograft. All dogs were given azathioprine and prednisone postoperatively for immunosuppression. Four of 6 dogs given pretransplantation transfusions were healthy 1 year after surgical manipulation was done, and 2 died for reasons other than graft rejection. Of the 6 dogs that were not given pre-transplantation transfusions, 3 were healthy after 1 year, but 2 were euthanatized because of graft rejection, and the last was euthanatized because of both graft rejection and intussusception.

Other complications in these dogs were leukopenia (7 dogs), interdigital abscesses (2 dogs), urinary infection (3 dogs), and renal vein thrombosis (1 dog).

Considering the lack of alternative methods for effective therapy for chronic renal failure in dogs, results of this study seem encouraging for selective use of renal transplantation, clinically. This study supports previous reports which indicated that pretransplantation transfusion enhanced graft survival in dogs.
Application of the log-linear and logistic regression models in the prediction of systemic lupus erythematosus in the dog
Authors: Kass Philip H. , Farver Thomas B. , Strombeck Donald R. , Ardans Alex A.
Published: February 2025

This study sought to mathematically define canine systemic lupus erythematosus (sle) by unifying diagnostic criteria proposed by others. Thirty-one cases of canine sle were selected for modeling when 4 different published schemes agreed on the diagnosis, and 122 controls were selected when a patient's status met no scheme's criteria. The log-linear method showed an association between sle and polyarthritis, hematologic abnormalities, renal damage, dermatologic disorders, and antinuclear antibody test response (positive). Logistic regression was then used to derive a predictive algorithm that could identify cases and controls with which all published criteria would be in accordance. The final equation correctly classified 93.5% of the affected dogs and 98.4% of the controls. It was concluded that the log-linear and logistic regression models are useful for the diagnosis of clinically similar, but distinguishable, disease states.
Intradermal testing of swine to monitor changes in delayed hypersensitivity response
Authors: Mann D. , Hargis J. W.
Published: February 2025

Pigs were tested (intradermal injection) on the abdomen with either phytohemagglutinin (pha) or pha and tuberculin. The response to pha was consistent; double-skin thickness averaged 247% of the preinjection thickness during daily testing. Pigs that were primed with Freund's complete adjuvant had a mean double-skin thickness of 208% for tuberculin and 236% for pha, indicating that the mitogen induced an antigen-like response. Unexpectedly, injections of dexamethasone (0.1 mg/kg of body weight on 2 days) increased the reactivity to both tuberculin and pha, indicating that the lymphocyte and macrophage response to dexamethasone in swine may be slightly different than the response reported in other species.
Detection of geographic isolates of Anaplasma marginale, using polyclonal bovine antisera and microfluorometry
Authors: Goff W. L. , Winward L. D.
Published: February 2025

Geographically separate United States isolates of Anaplasma marginale were differentiated, using polyclonal bovine antiserum and microfluorometry. Both isolate-common and restricted antigen-specific antibodies were apparent in sera of splenectomized calves after resolution of infection, as judged by the capability of the antisera to recognize heterologous isolate antigens to a lesser extent than homologous antigens. Furthermore, absorption of the antisera with homologous antigens removed homologous and heterologous reactions, whereas heterologous absorptions resulted in the capability to discriminate the tailed or appendage-associated isolates (Virginia and Washington) from the tail-less isolate (Florida).
In vivo effect of ascorbic acid on neutrophil function in healthy and dexamethasone-treated cattle
Authors: Roth James A. , Kaeberle Merlin L.
Published: February 2025

Ascorbic acid (20 mg/kg of body weight) administered subcutaneously to otherwise nontreated cattle resulted in enhancement of neutrophil oxidative metabolism and capability of neutrophils to mediate antibody-dependent cell-mediated cytotoxicity (adcc). Random migration, bacterial ingestion, and iodination by neutrophils was unaffected. Three dosage levels of ascorbic acid (10 mg/kg, 20 mg/kg, and 40 mg/kg) were examined for their effects on neutrophil function in cattle treated with dexamethasone (0.04 mg/kg). Dexamethasone administration caused an enhancement of neutrophil random migration and a suppression of neutrophil oxidative metabolism, iodination, and adcc. None of the dosage levels of ascorbic acid had an effect on the alterations in the wbc count induced by dexamethasone. The ascorbic acid did tend to reverse the effects of dexamethasone on neutrophil random migration, oxidative metabolism, and adcc in a dose-dependent manner, with the lowest dose having no discernible effect. Ascorbic acid administration also tended to enhance Staphylococcus aureus ingestion by bovine neutrophils. These results indicate that ascorbic acid should be further investigated for its potential to reduce the susceptibility of stressed or glucocorticoid-treated cattle to infective processes.
Transient enhancement of the serum antibody response to Brucella abortus strain 19 in cattle treated with levamisole
Authors: Confer A. W. , Hall S. M. , Espe B. H.
Published: February 2025

Two experiments were done on 57 steers. These cattle were allotted to 8 groups (4 groups/experiment) and vaccinated with 1 to 3 × 109 colony-forming units of Brucella abortus strain 19. Cattle in 3 of the 4 groups/experiment were given 6 mg of levamisole/kg, subcutaneously, either at the time of vaccination (day 0), 7 days later, or at both times. Serum antibody titers to B abortus were measured sequentially for 28 days in experiment 1 and for 56 days in experiment 2, using the card test, Rivanol test, complement-fixation test, fluorometric immunoassay, and an enzyme-linked immunosorbent assay. In general, the highest mean antibody titers, as determined by all serologic tests, occurred in steers treated with levamisole at 7 days after vaccination or in those treated at the time of vaccination and 7 days later. By the card test on day 56, there was a significantly (P < 0.05) greater number of seropositive cattle among those given levamisole 7 days after vaccination than among those given strain 19 alone. Simultaneous administration of strain 19 and levamisole did not alter antibody responses to B abortus.
Response of cattle persistently infected with noncytopathic bovine viral diarrhea virus to vaccination for bovine viral diarrhea and to subsequent challenge exposure with cytopathic bovine viral diarrhea virus
Authors: Bolin S. R. , McClurkin A. W. , Cutlip R. C. , Coria M. F.
Published: February 2025

Nine steers persistently infected with noncytopathic bovine viral diarrhea (bvd) virus were allotted into 3 groups (3 cattle/group). Cattle in group A were vaccinated with a modified-live bvd virus vaccine of porcine cell origin, cattle in group B with a modified-live bvd virus vaccine of bovine cell origin, and cattle in group C with a killed bvd virus vaccine of bovine cell origin. Detrimental effects due to vaccination were not seen. Six weeks after vaccination, the steers were challenge exposed with a cytopathic bvd virus. All steers developed mucosal disease after challenge exposure, produced antibodies that neutralized various isolates of bvd virus, and remained persistently infected until death. Steers given killed virus vaccine had a minimal neutralizing-antibody response and developed mucosal disease as quickly as reported for challenge-exposed, nonvaccinated, persistently infected cattle. Steers given modified-live virus vaccines had higher neutralizing-antibody response and longer intervals from challenge exposure to development of mucosal disease. The specificity of the neutralizing-antibody response differed between groups of vaccinated cattle.
Flunixin meglumine given in small doses: Pharmacokinetics and prostaglandin inhibition in healthy horses
Authors: Semrad S. D. , Hardee G. E. , Hardee M. M. , Moore J. N.
Published: February 2025

The pharmacokinetics and inhibition of prostaglandin synthesis in conscious horses given various dosages of flunixin meglumine were studied. Plasma concentrations of flunixin were measured by high-performance liquid chromatography, and serum thromboxane B2 and 6-keto prostaglandin F1α were quantitated by radioimmunoassay. Within the dosage range studied, linear pharmacokinetics were achieved. After iv administration of flunixin (1.1 mg/kg, 0.25 mg/kg, 0.1 mg/kg), significant suppression of serum thromboxane generation persisted for 12, 4, and 3 hours, respectively. Repeated administrations of flunixin (0.25 mg/kg) once every 8 hours maintained significant suppression of thromboxane generation for the duration of treatment. After treatment with flunixin was stopped, serum thromboxane generation exceeded base line (pretreatment values). Among the groups, significant alteration of 6-keto prostaglandin F1α production was not observed.
Comparison of neutrophil elastases and of neutrophil protease inhibitors in the horse and man
Authors: von Fellenberg R. , Kohler L. , Grùnig G. , Pellegrini A.
Published: February 2025

Neutral neutrophil protease, elastase activities, and cytosol protease inhibitors of these enzymes of horses and man were compared. Human neutrophils had 5 times the elastase activity of equine neutrophils, and neutral protease activity was approximately 50% greater in human neutrophils than that in equine neutrophils.

Cytosol inhibitors for elastase and neutral proteases were not found in human neutrophils, whereas large amounts were found in equine neutrophils. Using fibrinogen-agarose electrophoresis, 4 cytosol inhibitors of different enzyme specificities were detected. These cytosol inhibitors were differentiated on the basis of different electrophoretic migration and on the basis of differences in enzyme specificity.
Effect of intra-articular Gentamicin sulfate on normal equine synovial membrane
Authors: Stover Susan M. , Pool Roy R.
Published: February 2025

Gentamicin sulfate (3 ml; 50 mg/ml) was administered intra-articularly into 30 normal equine radiocarpal joints after arthrocentesis. Arthrocentesis alone was performed on 10 normal radiocarpal joints. Synovial fluid evaluations and gross and microscopic examinations were performed on synovial fluid and synovial membrane of designated joints at selected daily intervals over a period of 10 days. Synovial fluid from gentamicin-injected joints had greater turbidity, higher RBC and WBC counts, and higher refractive indices than did joints not injected with gentamicin. The largest increases developed on days 1 or 2 after gentamicin injection, with mean total WBC, large mononuclear cell, small mononuclear cell, and polymorphonuclear cell counts of 23,860, 11,853, 857, and 11,150 cells/μl, respectively. Arthrocentesis alone resulted in smaller increases in these counts. Microscopic changes seen in the synovial membrane of gentamicin-injected joints included edema, leukocytic infiltration, and loss of synovial lining cells. These inflammatory changes resolved within 7 days after gentamicin injection.
Goat papillomatosis
Authors: Theilen G. , Wheeldon E. B. , East N. , Madewell B. , Lancaster W. D. , Munn R.
Published: February 2025

The present study indicates that the development of caprine mammary gland warts seems to depend on several factors—namely, nonpigmented skin, adult age, excessive exposure to sunlight, and contact with a yet undefined infective agent. Three types of goat papillomas are described: (1) mammary, (2) cutaneous, other than mammary, and (3) genital. Warts on animals lacking pigmented skin are more frequent in adult animals that live in areas where there is abundant sunlight. Mammary gland papillomas are the most numerous and occur in different stages; ie, (1) goats with mammary gland papillomas that regress, never to recur, (2) goats with papillomas that regress in the winter and reoccur in summer, (3) goats with persistent papillomas of which some are from the group that had previous winter time regression, and (4) goats that have progression of persistent papilloma to carcinoma. Saanen, Saanen crossbreeds, and goats of other breeds that lack pigmented skin and live in sunbelt areas are at high risk for papillomatosis. An infective agent was not defined even after electron microscopic, immunocytochemical, and DNA-DNA hybridization studies, Yet, there is high probability that an infective agent is involved, because mammary gland papillomas usually occur in the susceptible herd 4 to 6 months after an affected goat is introduced.
Experimentally induced pneumonic pasteurellosis: Dose-response relationships and protection against natural reinfection in calves
Authors: Hilwig Ronald W. , Songer J. Glenn , Reggiardo Carlos
Published: February 2025

Calves were inoculated intranasally with 2 × 106.2 tissue culture infective doses of infectious bovine rhinotracheitis virus, followed in 7 days by intratracheal inoculations with 1 of 4 challenge doses of pathogenic Pasteurella haemolytica. Severity and duration of the ensuing clinical signs of respiratory tract disease were correlated with the challenge dose of bacteria. Calves given 1 × 106 colony-forming units (cfu) of bacteria did not develop reliable clinical evidence of disease, whereas those given 1 × 108 cfu or 1 × 1010 cfu of bacteria developed clinical signs of pneumonic pasteurellosis within 12 to 24 hours of bacterial challenge. Severity of clinical signs was equal at the 108 and 1010 doses of bacteria, but duration of clinical signs was greater in calves given the 1010 dose. Calves given 1 × 1012 cfu of bacteria developed relatively severe respiratory tract disease in excess of what was necessary for positive clinical detection.

Positive correlations were found between the bacterial challenge dose and the height and duration of increased rectal temperature, amount and duration of increases in ocular and nasal discharges, and the subjective evaluation of depressed attitude and appetite. Correlations were not found between challenge dose and respiratory rate or character, or between challenge dose and complete blood cell count.

Convalescent calves were resistant to naturally occurring pneumonic pasteurellosis, which caused severe disease in nontreated calves. Adverse effects of P haemolytica were not observed after the first 4 to 15 days after bacterial administration; however, the bacteria were isolated from nasal secretions of convalescent calves 89 to 116 days after bacterial inoculation. Serum antibody titers increased within 15 days of bacterial inoculation, but did not correlate with the challenge dose of bacteria or with the presence or absence of clinical signs of respiratory tract disease.
Isolate of Anaplasma marginale not transmitted by ticks
Authors: Smith Ronald D. , Levy Michael G. , Kuhlenschmidt Mark S. , Adams John H. , Rzechula Dana L. , Hardt Thomas A. , Kocan Katherine M.
Published: February 2025

The tick-borne transmissibility of 2 isolates of Anaplasma marginale was compared. Dermacentor variabilis were exposed to A marginale as nymphs by feeding on 1 of 4 splenectomized calves during periods of ascending parasitemia (maximum 49% to 81% parasitized erythrocytes) induced by injection of a stabilate. Tick-borne transmission was attempted, using 26 to 224 adult ticks within 30 to 220 days after molting. Adult D variabilis did not transmit an Illinois isolate of A marginale in 7 tick-borne transmission experiments (P = 0.0047), including 2 experiments in which calves were inoculated IV with homogenates of adult ticks. In contrast, a Virginia isolate of A marginale was readily transmitted by the same tick colony. Thus, previously reported morphologic and immunologic differences among A marginale isolates may extend to tick-borne transmissibility. The Virginia and Illinois A marginale isolates had an inclusion appendage that was not a marker for tick transmissibility.
Effect of decoquinate on the control of coccidiosis in young ruminating calves
Authors: Fitzgerald P. R. , Mansfield M. E.
Published: February 2025

Twenty-five 6-week-old Holstein male calves were each inoculated with 500,000 sporulated oocysts of Eimeria bovis. Two nontreated (control) and 3 treated calves (1.5 mg of decoquinate/kg of body weight in feed) were necropsied 7 days after inoculation. Similar groups of calves were necropsied at 12, 18, 22, and 28 days after inoculation. Treated calves were started on medicated feed 2 days before inoculation or at 7, 12, or 15 days after inoculation or were on continuous medication from the day of inoculation. Control calves were not given medication.

Early schizonts were in the small intestines of control calves at 7 days after inoculation, but none was in the treated calves that were started on medicated feed 2 days before inoculation. Schizonts were present in the small intestine of both treated and control calves at 12 days after inoculation. At 18 days after inoculation, control calves had schizonts in the small intestine and gamonts and oocysts in the cecum and large intestines, but treated calves only had schizonts in the small intestine. At 22 days, control calves had schizonts in the small intestine and gamonts and oocysts in the large intestine; treated calves had schizonts in the small intestine. At 28 days, controls still had schizonts in the small intestine and gamonts and oocysts in the cecum and large intestine; the treated calves that had been on continuous medication did not have schizonts, gamonts, or oocysts in the tissues.

Decoquinate apparently kills sporozoites or arrests development and release of merozoites from the schizonts when fed at 1.5 mg/kg of body weight in the feed.
Depressed neutrophil chemotactic stimuli in supernatants of ionophore-treated polymorphonuclear leukocytes from selenium-deficient goats
Authors: Aziz E. S. , Klesius P. H.
Published: February 2025

The effect of dietary selenium (Se) deficiency on the generation of neutrophil chemotactic factors from goat polymorphonuclear leukocytes (pmn) was studied. Polymorphonuclear leukocytes were isolated from 2 groups of crossbred goats. One group (n = 3) was fed a diet deficient in Se; the other (n = 3) was fed a diet adequate in Se. The pmn from each goat were stimulated with calcium ionophore A23187 and supernatants were collected. Each supernatant was immediately assayed for its ability to elicit neutrophil chemotaxis (nct) and neutrophil chemokinesis by the Boyden chamber technique and neutrophil chemiluminescence (ncl) by the luminol-dependent chemiluminescence assay. Measurements from each group were compared, using the Student's t test. There was no significant difference (P > 0.01) in neutrophil chemokinesis elicited by supernatants derived from stimulated pmn from the 2 groups. However, supernatants derived from pmn of goats fed the Se-deficient diet had a significantly decreased capacity (P < 0.01) to stimulate nct and ncl. In vitro incubation of pmn with Se before ionophore treatment produced supernatants with increased ncl stimulation (P < 0.05), but none with increased nct stimulation (P > 0.05). However, both activities were restored after goats fed the Se-deficient diet (P < 0.01) were given Se subcutaneously. Seemingly, dietary Se deficiency is associated with depressed pmn generation of factors that stimulate nct and ncl. In contrast to ncl factors, synthesis of factors stimulating nct probably was not associated directly with pmn glutathione peroxidase concentration.
Aflatoxin B1 toxicosis in dairy calves pretreated with selenium-vitamin Ε
Authors: Brucato Michael , Sundlof Stephen F. , Bell John U. , Edds George T.
Published: February 2025

Effects of a single im injection of selenium-vitamin Ε (Se-E; 5 mg of Se + 68 IU of α-tocopherol/60 kg of body weight) as a pretreatment 14 days before an oral dose of aflatoxin B1, (1.0 mg/kg) were studied in 24 dairy calves. Treatment groups were designated as follows: group 1 = no Se-E or aflatoxin B1 (control); group 2 = Se-E supplementation only; group 3 = aflatoxin B1 dose only; and group 4 = Se-E supplementation before aflatoxin B, dose. Clinical signs of toxicosis in aflatoxin B1-treated calves included anorexia, ataxia, rough haircoats, increased respiration rates, dyspnea, dehydration, and nasal discharge. Packed-cell volume, rbc, wbc, and hemoglobin were increased in aflatoxin-treated calves. Significant increases in serum aspartate aminotransferase (P < 0.05) and γ-glutamyl-transferase (P < 0.001) activities and prothrombin times (P < 0.001) were observed in aflatoxin-treated calves, indicating that there was hepatic involvement. Although aflatoxin exposure caused a significant decrease in body weight (P < 0.01) and feed intake (P < 0.001) in treatment groups 3 and 4, Se was demonstrated to interact significantly (P < 0.001) with aflatoxin B1 for feed intake, causing an improved feed intake in treatment group 4 calves.
Cervicothoracic (stellate) ganglion block in conscious horses
Authors: Skarda R. T. , Muir W. W. , Swanson C. R. , Hubbell J. A. E.
Published: February 2025

Seven adult horses were used to compare the cardiovascular and respiratory effects of unilateral (right side) and bilateral cervicothoracic ganglion (ctg) blockade. An 18-gauge, 25-cm needle was placed midventrally between articulations of the 1st and 2nd ribs from a cranial and paratracheal site. One gram of lidocaine HCl in aqueous solution (100 ml) was used to infiltrate the ctg. Cervicothoracic sympathetic blockade was characterized by Horner's syndrome, increased skin temperature and profuse sweating over the face, neck, and thoracic limb. Comparison of base-line data with data obtained during unilateral and bilateral ctg blockades indicated a significant (P < 0.05) decrease in respiratory rate, significant (P < 0.05) increases in arterial oxygen, and carbon dioxide tensions, and a significant increase in subcutaneous temperature at the neck and shoulder. Systolic, diastolic, and mean aortic blood pressures, pulse pressure, rectal temperature, arterial pH, bicarbonate, pvc, and total solid concentration did not change significantly from base-line values. Arterial O2 tension was significantly (P < 0.05) less in horses with bilateral ctg blockade than in horses with unilateral ctg blockade. In 4 horses without cervicothoracic sympathetic blockade that were given lidocaine (1 g in 100 ml) in the right cervicothoracic region, cardiovascular and respiratory values did not change significantly from base-line values. The nonsedated healthy horse tolerated unilateral ctg blockade well. Bilateral and unilateral injections of 100 ml of 1% lidocaine into the ctg at intervals of < 2 hours induced bilateral recurrent nerve paralysis and airway obstruction.
Thoracic limb digital extensor denervation in young horses
Authors: Firth Elwyn C.
Published: February 2025

Low radial neurectomy in the left thoracic limb was performed in 4 mixed-breed weanling horses, with subsequent paralysis of the lateral and common digital extensor muscles. Weight bearing of the denervated and control limbs was discouraged by the use of special shoeing. Clinical signs of flexural deformity were not induced in the horses.
Controlled wound repair in guinea pigs, using antimicrobials that alter fibroplasia
Authors: Kenyon Alan J. , Hamilton Susan G. , Douglas Diane M.
Published: February 2025

The repair processes of incised wounds depend, in part, on fibroplasia induced by soluble mediators from monocytic macrophages. Two topical antimicrobials were evaluated, each of which effectively controlled wound sepsis and yet each had widely different effects on fibroplasia and wound strength. Paired-incision dermal wounds on the flanks of guinea pigs were treated with a substance containing reactive chlorine (Alcide) or with a compound that is a mixture of two surfactants. One side of each guinea pig was treated with one of the antimicrobials (treated wounds); the opposite side was treated with isotonic saline solution (control wounds). At 7, 10, and 16 days after surgery, tensiometric measurements of C31G (a surfactant)-treated wounds were 99%, 139%, and 195% of control wound values, respectively. Alcide-treated wounds were 76%, 58%, and 88% of control wounds, respectively. Wounds treated with Chlorhexidine had reduced strength at 7 days (73%) and at 10 days (78%), but by 14 days, they were similar to control wounds (94%). The main difference between the wounds was the amount of collagen formation. Alcide-treated wounds incorporated < 50% of the amount of 14C-proline than did the wounds treated with C31G. However, Alcide-treated wounds epithelialized as rapidly as did control wounds, and had minimal scar formation. Microscopic evaluations indicated greatly reduced inflammatory infiltrates in Alcide-treated wounds, indicating that reduced wound strength may be associated with lack of fibroblast-stimulating activity by monocytes.
Frequency and antimicrobial susceptibility of Staphylococcus species isolated from canine pyodermas
Authors: Medleau Linda , Long Richard E. , Brown John , Miller William H.
Published: February 2025

Specimens obtained from pyogenic skin lesions of 210 dogs were culturally examined for staphylococci. A total of 215 isolates of staphylococci were biotyped, using the biochemical tests contained in a commercial staphylococcal identification system. Of 201 coagulase-positive isolates, 197 were identified as Staphylococcus intermedius, 3 as S aureus, and 1 as S hyicus. Of 14 coagulase-negative isolates, 5 were identified as S epidermidis, 5 as S xylosus, 3 as S simulons, and 1 as S hominis.

Antimicrobial susceptibility tests were done on all staphylococcal isolates, using the standard disk-diffusion method. Staphylococcus intermedius isolates were susceptible to cephalothin, methicillin, and gentamicin. Resistance to ampicillin, penicillin G, and tetracycline was frequent. Antibiotic resistance was not associated with the depth of skin infection. Resistance to ampicillin, penicillin, tetracycline, and trimethoprim-sulfamethoxazole was not associated with previous antibiotic use. Increased resistance to chloramphenicol, clindamycin, and erythromycin was associated with previous antibiotic therapy. Antimicrobial susceptibilities of the other Staphylococcus species isolated are reported, but the small numbers of these species precluded making meaningful comparison with S intermedius.
Mineral and amino acid composition of beef cattle hooves
Authors: Hidiroglou M. , Williams C. J.
Published: February 2025

Twenty-three Hereford × Shorthorn cattle were used to evaluate the effects of seasonal and dietary changes on the mineral composition (Ca, Mg, Cu, Zn, and S) of hooves. A seasonal pattern was found in the Ca, Mg, and Zn composition of hooves in the 12 cattle evaluated in 1982 and in the 11 cattle evaluated in 1983, with the concentrations of 3 minerals decreasing in winter when dietary change did not occur. Copper concentrations significantly decreased during the 1st year (1982) and had a tendency to decrease during the 2nd year. During the 1983 pasturing season, when effects of seasonal vs dietary change could not be distinguishable, hoof concentrations of Ca and Mg decreased, whereas the inverse trend was observed for Cu and Zn. Seasonal patterns for hoof concentrations of S were not found. Results of mineral analysis of hooves indicated strong correlations between calcium and the other minerals (except S), and between Zn and Cu. Amino acid analyses of hooves of the 11 cattle in 1983 indicated differences in their composition related to dietary changes (winter feeding vs pasture) or to management.
Canine Dirofilaria immitis infection in a hyperenzootic area: Examination by parasitologic findings at necropsy and by two serodiagnostic methods
Authors: Grieve Robert B. , Glickman Lawrence T. , Bater Alan K. , Mika-Grieve Marcia , Thomas Chester B. , Patronek Gary J.
Published: February 2025

A total of 174 dogs from an area hyperenzootic for Dirofilaria immitis were grouped into 4 age categories and necropsied; information was obtained on adult D immitis infections and on the presence of microfilariae. Serum samples from these dogs were examined by an enzyme-linked immunosorbent assay (elisa) for antibody to adult D immitis and by an indirect fluorescent antibody test (ifat) for antibody to microfilarial surface antigens.

In dogs ≥ 5 months of age, necropsy demonstrated no evidence of infection; however, positive serologic results indicated that some of these dogs had prepatent infections. The percentage of dogs with elisa titers (positive) increased with age, as did the percentage of dogs with adult D immitis infections. The ifat results were positive in some dogs in each age category.

Sera from all 29 dogs with occult infections were positive by elisa. Sera from 6 of 20 dogs with occult dual-sex heartworm infections and 1 of 9 dogs with occult single-sex heartworm infections were positive by ifat. For diagnosing occult dirofilariasis, the elisa had a positive predictive value which increased with age of the dog to a maximum of 65.0% in dogs ≥ 12 months of age; elisa had a negative predictive value of 100% in all age groups. In contrast, positive and negative predictive values for the ifat decreased with age of the dog to 60% and 37.5%, respectively, in dogs ≥ 12 months of age.
Continuous-flow centrifugation hemapheresis in the horse
Authors: Gordon B. J. , Latimer K. S. , Murray C. M. , Moore J. N.
Published: February 2025

In a continuous-flow centrifugation apheresis technique adapted for blood-component separation and collection in horses, hydroxyethyl starch was not required for erythrocyte sedimentation.

The efficacy and separation characteristics of whole blood from 10 horses were evaluated at various gravitational forces (700 to 1,500 rpm), using a constant withdrawal rate (100 ml/min). Maximum leukocyte collection occurred at 700 rpm (P < 0.01), and optimal neutrophil collection occurred at 700 to 750 rpm (P < 0.01). Although neutrophil counts decreased and lymphocyte counts remained constant at higher rpm settings, an optimal rpm range could not be determined for lymphocyte collection. Peak platelet collection occurred at 1,500 rpm.

The response of whole blood from 5 horses was evaluated at lower (500 to 700 rpm) and higher (1,400 to 2,200 rpm) centrifuge speeds. A constant whole blood withdrawal rate of 100 ml/min and a leukocyte collection rate of 3 ml/min were maintained. The optimal rpm settings were determined and compared with values obtained from the 10 horses. Significant differences (P < 0.01) did not exist between maximum numbers of leukocytes collected at low and high speeds. There was a significant (P < 0.01) decrease in neutrophils and a concomitant increase in the numbers of lymphocytes recovered at the higher rpm. Platelet yields increased as rpm was increased to 2,000.
Scanning electron microscopy of bovine corneas irradiated with sun lamps and challenge exposed with Moraxella bovis
Authors: Vogelweid C. M. , Miller R. B. , Berg J. N. , Kinden D. A.
Published: February 2025

Effects of uv radiation and irradiation followed by challenge exposure with Moraxella bovis on the corneal epithelium were studied in 6 calves by scanning electron microscopy. After UV irradiation, the number of dark cells comprising the surface epithelium increased. Many epithelial cells were in various states of degeneration and were characterized initially by large round nuclei, whereas sloughing and peeling were characteristic of the last degenerative stage. All M bovis-infected irradiated eyes had large numbers of degenerating cells, deep epithelial defects, fibrin strands, surface inflammatory cells, and debris. A few M bovis organisms were randomly attached to the cornea before visible ulceration. There were many inflammatory cells between the ulcerated corneal epithelium and adjacent nonulcerated epithelium. Epithelial cells at the margin of the ulcer appeared swollen. Light, dark, and intermediate epithelial cell types could not be distinguished peripheral to the ulcer.
Malignant lymphoma in a Sinclair miniature pig
Authors: Skavlen Patricia A. , Stills Harold F. , Caldwell Charles W. , Middleton Charles C.
Published: February 2025

Malignant lymphoma was diagnosed in a 3-year-old, male Sinclair(S-1) miniature pig with acute anorexia, depression, fever, and markedly enlarged inguinal lymph nodes. Results of an initial hemogram indicated a leukocyte count of 121,489 cells/mm3. Most of the leukocytes were mononuclear cells of various sizes, nuclear chromatin pattern, number of nucleoli, amount of cytoplasm, and amount of staining. Cytochemical staining and flow cytometric evaluation of the leukocytes indicated a large number of hypodiploid lymphoblasts in the peripheral blood. Gross necropsy findings included enlargement of all lymph nodes, a pale liver, and multifocal pale areas scattered throughout the kidneys. Microscopic examination indicated massive infiltration of abnormal lymphoid cells into most major organs and complete loss of normal morphologic features of all lymph nodes.
Myocardial ultrastructural alterations in ducklings with isoproterenol-induced cardiotoxicosis
Authors: Okerberg Carlin V. , Van Vleet John F.
Published: February 2025

Fifty-two, 8-week-old, male White Pekin ducklings (Anas platyrhynchos domesticus) were allotted into control (n = 7) and isoproterenol-injected groups (n = 45). One control duck and 5 to 7 isoproterenol-injected (200 mg/kg of body weight) ducklings were euthanatized at postinjection hours (pih) 1, 12, and 24 and at postinjection days (pid) 2, 4, 7, and 14. The left ventricular myocardium was examined, using electron microscopy. The earliest ultrastructural alteration in damaged myocytes was myofibrillar lysis at pih 12. At pih 24, affected myocytes had necrosis with mineralization of mitochondria. By pid 2, macrophages had invaded into areas of myocardial necrosis, mineralization was prominent in myocyte mitochondria, and dedifferentiated myocytes with reduced numbers of myofibrils, increased numbers of polysomes, large nuclei, and prominent nucleoli were first observed. The primary myocardial finding at pid 4, 7, and 14 was 2 populations of sublethally damaged myocytes. One population of injured myocytes had numerous polysomes in the sarcoplasm and large nuclei with prominent nucleoli, indicating attempts at repair of myofibrillar damage. The 2nd population of myocytes with myofibrillar lysis did not have morphologic evidence of myofibrillar repair. Therefore, the sequential ultrastructural alterations of damage and repair induced by isoproterenol in the duckling myocardium provided a model for comparative studies of cardiotoxicity.
Guinea pig erythrocyte rosette formation as a nonspecific cell surface receptor assay in the cat
Authors: Wellman Maxey L. , Kociba Gary J. , Rojko Jennifer L.
Published: February 2025

The specificity of guinea pig erythrocyte (gpe) rosettes for feline peripheral blood lymphocytes was studied. Of the gpe rosette-positive cells from peripheral blood, 54% were monocytes, 29% were granulocytes, and only 17% were lymphocytes. Results were similar for rosettes incubated at 4 C and those incubated at 37 C.

Mononuclear cells separated with polyvinylpyrrolidone-coated silica formed fewer monocyte rosettes (49%) and more granulocyte rosettes (34%) than did cells separated with sodium diatrizoate-Ficoll (60% monocyte rosettes and 18% granulocyte rosettes), whereas the percentage of lymphocyte rosettes was similar for both media. Mononuclear cells suspended in Eagle's minimum essential medium had a higher percentage of monocyte rosettes (75%) and a lower percentage of granulocyte rosettes (12%) than did cells suspended in RPMI 1640 medium (59% monocyte rosettes and 27% granulocyte rosettes). The percentage of lymphocyte rosettes was similar in the 2 media. Two sequential 45-minute plastic adherent cell depletions decreased monocyte rosettes to 51% and increased lymphocyte rosettes to 23% compared with 63% monocyte rosettes and 12% lymphocyte rosettes before adherent cell depletion. The granulocyte rosettes were unchanged by plastic adherent cell depletion.

The percentage of rosette-positive cells (9%) was not significantly affected by incubation at 4 C or 37 C, cell separation with polyvinylpyrrolidone-coated silica or lymphocyte separation medium, or suspension in Eagle's minimum essential medium or RPMI 1640 medium. Plastic adherent cell depletion decreased the percentage of rosette-positive cells.

Feline thymocytes were 38% to 80% gpe rosette-positive and a feline leukemia virus-infected lymphoblastic cell line (F422) was 88% gpe rosette-positive. Although a high percentage of thymocytes and cultured feline leukemia virus-infected lympho-blasts may be gpe-receptor positive, gpe receptors were not specific for peripheral blood T cells in the cat.
Effects of sodium dichloroacetate in awake, healthy, Yucatan miniature swine
Authors: Weingand Kurt W. , Fettman Martin J. , Phillips Robert W. , Hand Michael S.
Published: February 2025

Four healthy, fully conscious, 50- to 80-kg Yucatan miniature swine were fitted with carotid artery and jugular, portal, and hepatic vein catheters and hepatic artery and portal vein flow cuffs to determine transhepatic kinetics and insulin secretion. Three days later, after a 3-hour control period, the pigs were given iv sodium dichloroacetate (30 mg/kg of body weight as a bolus and 30 mg/kg/hr, as an infusion) for 6 hours.

Arterial lactate concentrations decreased during the dichloroacetate infusion, but pyruvate concentrations were unaltered. The whole body rate of appearance and disappearance of glucose decreased, but plasma glucose concentrations did not change markedly. Limb skin surface temperatures increased, indicating a peripheral vasodilatory effect. Dichloroacetate had little effect on mean arterial pressure and hepatosplanchnic blood flow. Dichloroacetate may be effective as a hypolactatemic agent for lactic acidosis in pigs.
Effectiveness of oxfendazole against early and later 4th-stage Strongylus vulgaris in ponies
Authors: Slocombe J. O. D. , McCraw B. M. , Pennock P. , Ducharme N. G. , Baird J. D.
Published: February 2025

Twenty pony foals (reared worm free), 6.5 to 10 weeks of age, were inoculated with Strongylus vulgaris and allocated to 5 groups, each with 4 foals. One week after inoculation, 1 group of 4 foals was given oxfendazole (ofz) at a dosage rate of 10 mg/kg of body weight, another group was given 2 such treatments 48 hours apart, and a 3rd group was given a placebo. All treatments were administered by stomach tube. Three weeks later, foals were euthanatized and necropsied in a test for efficacy against early 4th-stage larvae. Oxfendazole was 80% and 94.9% effective against early 4th-stage S vulgaris with 1 and 2 doses, respectively. A 4th group of 4 foals was given 2 treatments of ofz, 48 hours apart, about 8 weeks after inoculation, and a 5th group was given a placebo. These foals were euthanatized and necropsied 5 weeks after treatment in a test for efficacy against later 4th-stage larvae. Two doses of ofz were 96.6% effective against later 4th-stage larvae.