bluuebunny/crossref_metadata_2025 huggingface dataset:
Hemagglutination by psittacine beak and feather disease virus and use of hemagglutination inhibition for detection of antibodies against the virus
Authors: Ritchie Branson W. , Niagro Frank D. , Latimer Kenneth S. , Steffens W. L. , Pesti Denise , Lukert Phil D.
Published: January 2024

Conditions for psittacine beak and feather disease (pbfd) virus hemagglutination and hemagglutination-inhibition (hi) test reactions are defined. The pbfd virus was found to hemagglutinate cockatoo and some guinea pig erythrocytes. The hi test was used to assay serum antibody titer in birds with active pbfd virus infections and in others that had been exposed to diseased birds. On the basis of hi antibody titers in psittacine birds that had been exposed to pbfd virus, but remained clinically normal, we suggest that some birds exposed to the virus are able to mount an effective immune response. Birds with active pbfd virus infections had lower antibody values than did birds that had been exposed to the virus, but remained clinically normal. On the basis of these findings, the ability to develop a suitable hi antibody response may be crucial in determining the disease status of susceptible birds exposed to the pbfd virus. If hi antibodies are found to have neutralizing activity, then the fact that a high hi titer was induced in birds inoculated with purified pbfd virus might suggest that an immunization program would be effective in preventing pbfd virus infections.
Evaluation of multiple reticulorumen selenium pellets as a health risk in growing Hereford steers
Authors: Wilson D. J. , Norman B. B. , Hird D. W. , Wilson C. B. , Oliver M. N.
Published: January 2024

Five groups of Hereford steers were monitored for 293 days. One group of 3 was not given selenium supplementation; the other 4 groups of 3 steers each were given 2, 4, 6, or 8 reticulorumen selenium pellets. Health, body weight, and blood selenium concentration were monitored during the study. At the finish, steers were slaughtered, and various tissues from the carcasses were analyzed for selenium content. Initial blood selenium concentration did not differ significantly among groups. However, significant (α = 0.01) difference among means was detected during the early period of rapid increase in blood selenium concentration in steers of supplemented groups. Means of maximal blood selenium concentration also differed among groups; however, even the highest value, 0.253 μg/g, was lower than the 3 μg/ml reported in chronic clinical cases of toxicosis in the literature. Carcass analysis indicated significant (α = 0.05) differences in selenium concentrations among treatment groups for almost all tissues tested. Only kidney samples (7.9 μg/g) from steers of the 8-pellet treatment group exceeded published normal values (7.6 μg/g). Health variables for most dates were not significantly different among groups, and selenium toxicosis was not evident in any steer. Analysis did not indicate risk to human beings consuming tissues from these steers.
Correlation of morphologic features of the iridocorneal angle to intraocular pressure in Samoyeds
Authors: Ehesten Björn , Narfström Kristina
Published: January 2024

The iridocorneal angle of the left eye was investigated in 203 Samoyeds. Comparison was made of judgements of the width of the anterior opening of the ciliary cleft when performing gonioscopy with an objective method of estimation based on measurements on goniophotographs. Results indicated high degree of correlation. Various degrees of narrowness of the iridocorneal angle width were revealed and clinical glaucoma with total-angle closure was found in 6 of 203 dogs. The intraocular pressure was significantly (P < 0.01) higher in eyes with closed iridocorneal angles than in eyes with any other width of the angle. Appearance of the structures of the iridocorneal angle, particularly the pigment bands, indicated extensive individual variation. In approximately 25% of the eyes, dysplasia of the pectinate ligaments of variable degree existed, indicating that this anomaly is common in the Samoyed breed. Significant difference was not evident in intraocular pressure in eyes with different degrees of dysplasia of the pectinate ligaments.
Evaluation of two applanation tonometers in cats
Authors: Miller Paul E. , Pickett J. Phillip , Majors Lynda J. , Kurzman Ilene D.
Published: January 2024

Comparisons of the MacKay-Marg and Tono-Pen applanation tonometers in open and closed in vitro systems were made for the eyes of cats. Both instruments significantly underestimated intraocular pressure (iop) vs direct manometry (P < 0.001), but in readily predictable manner, with high coefficients of determination (r2 = 0.99). For tonometer 1 (MacKay-Marg), calculated actual iOP = 1.36 × (MacKay-Marg measurement) − 1.67 mm of Hg; and for tonometer 2 (Tono-Pen), calculated actual iop = 1.37 × (Tono-Pen measurement) + 0.8 mm of Hg, using measurements from 11 enucleated eyes. In vivo comparisons were initially made in 81 clinically normal eyes (n = 41 cats) by applying the Tono-Pen first followed by the MacKay-Marg. Compared with the MacKay-Marg, the Tono-Pen significantly (P < 0.001) underestimated iOP in these cats. When the order of tonometer applanation was subsequently reversed in 73 clinically normal eyes (n = 37 cats) the Tono-Pen again significantly (P < 0.001) underestimated iOP, compared with the MacKay-Marg. Alterations in tonometer order did not result in significant differences in measured iOP for the MacKay-Marg when compared with itself, but Tono-Pen measurements were significantly (P < 0.05) less when its use followed, rather than preceded, that of the MacKay-Marg. Mean (± sd) iop in clinically normal cats when each tonometer was used first was 22.6 ± 4.0 mm of Hg (range, 14 to 32 mm of Hg) for the MacKay-Marg and 19.7 ± 5.6 mm of Hg (9 to 31 mm of Hg) for the Tono-Pen. The mean (± sd) absolute value of the differences between MacKay-Marg measurements and those obtained by use of the Tono-Pen was 3.2 ± 3.1 (range, 0 to 13 mm of Hg difference).
Effects of treatment with aspirin or aspirin/dipyridamole combination in heartworm-negative, heartworm-infected, and embolized heartworm-infected dogs
Authors: Boudreaux Mary K. , Dillon Allen R. , Ravis William R. , Sartin Eva A. , Spano Joseph S.
Published: January 2024

To determine the drug dose required to inhibit platelet reactivity by at least 50%, 2 drug regimens were evaluated in heartworm-negative, heartworm-infected, and heartworm-infected dogs embolized with dead heart-worms. Aspirin, or a combination of aspirin and dipyridamole, were administered to 2 groups of Beagles (n = 5 each) for 5 to 9 days; a third group of 5 Beagles served as nontreated controls. For heartworm-negative dogs, mean (± sd) aspirin dosage that inhibited collagen-induced platelet reactivity by at least 50% was 6 (± 2) mg/kg of body weight given once daily. The aspirin/dipyridamole combination dosage was 1 mg of each drug/kg given every 12 hours. All dogs (n = 15) were implanted with 7 adult heartworms each and remedicated (or not treated) beginning at 21 days after heartworm implantation. In heartworm-infected dogs, mean aspirin dosage required to inhibit collagen-induced platelet reactivity ≥ 50% was 10 ( ± 6) mg/kg. Mean dosage of aspirin/dipyridamole combination was 1.6 ± (0.5) mg of each drug/kg given every 12 hours.

When platelet reactivity in response to collagen was determined to be inhibited by at least 50% in all medicated dogs, each dog (n = 15) was embolized with 7 dead adult heartworms to mimic heartworm adulticidal treatment. Platelet reactivity was monitored for 21 days after treatment, and drug dose was adjusted to maintain platelet inhibition by at least 50%. In embolized dogs, mean aspirin dosage was 17 (± 14) mg/kg given once daily. Mean dosage of the aspirin/dipyridamole combination was 2.8 (± 1.3) mg of each drug/kg given every 12 hours.

All dogs (n = 15) were euthanatized 21 days after heartworm embolization. Each lung lobe was evaluated for severity of lesions and presence of organized or fibrinous thrombi. Lesion severity in the aspirin- and aspirin/dipyridamole-treated dogs was not significantly different from that in control dogs.
Heterogeneity in phagocytic and nitroblue tetrazolium reductive properties of neutrophils from cows
Authors: Kabbur Mahendra B. , Jain Nemi C. , Zinkl Joseph G. , Farver Thomas B.
Published: January 2024

Phagocytic and nitroblue tetrazolium (nbt) reductive activities of blood neutrophils from 19 Holstein heifers were measured by light microscopic and spectrophotometric methods, respectively. These functional properties of neutrophils correlated well (r = 0.64) and varied significantly (P < 0.05) among animals studied. Variations in phagocytosis and nbt reductive activities attributable to the source of sera were determined in experiments in which cells from the same cows and zymogen particles opsonized with heat-inactivated autologous or homologous sera were used. Variations attributable to the source of cells were determined in experiments in which cells from different cows and particles opsonized with pooled sera from all the cows were used. Most of the variation in phagocytic properties and nbt reductive activities was attributable to the source of cells (ie, each cow). The source of sera contributed slightly to the variation in nbt reductive activities, but not to the phagocytic properties. These results support the concept of functional heterogeneity of neutrophils among cows.
Pathologic features of dogs inoculated with North American Trypanosoma cruzi isolates
Authors: Barr Stephen C. , Schmidt Stephen P. , Brown Corrie C. , Klei Thomas R.
Published: January 2024

Twenty-three clinically normal Beagles were inoculated with North American Trypanosoma cruzi isolates from an opossum (Tc-O), an armadillo (Tc-A), or a dog (Tc-D). The dogs were grouped according to the clinical outcome of inoculation. Group 1 consisted of 7 dogs inoculated with Tc-O or Tc-A that died or were euthanatized during acute stages of disease. Group 2 consisted of 5 dogs inoculated with Tc-O or Tc-A, that also developed acute disease, but survived to develop chronic disease. Group 3 consisted of 7 dogs inoculated with Tc-D neither developed acute nor chronic disease. Group 4 consisted of 4 dogs and served as noninoculated controls.

In group 1, the gross lesions were diffusely pale myocardiums with right ventricular enlargement, hepatomegaly, and a moderate amount of modified transudate in the abdominal cavity. Severe diffuse granulomatous myocarditis with large numbers of pseudocysts and minimal fibrosis characterized the tissues from all cardiac chambers and septum. The lesions were most severe in the right atrium and ventricle. Mild multifocal myositis and pseudocysts were observed in skeletal muscles and smooth muscles of the urinary bladder and small intestine. Multifocal encephalitis and pseudocysts were in the cerebral cortex, cerebellum, and brain stem.

In group 2, the gross lesions were biventricular enlargement and thinning of the ventricular free walls. The right ventricle contained the most severe microscopic changes. There were mild multifocal interstitial lymphohistiocytic cellular infiltrates, perivasculitis, and marked fibrosis in all areas of the myocardium. Mild myositis and multifocal encephalitis were seen in the skeletal muscles and brains. Pseudocysts were not observed in any tissues.

In group 3, there was mild biventricular dilatation, minimal inflammation with fibrosis in cardiac tissues, and a multifocal myositis in most skeletal muscles. Multifocal encephalitis was seen in the brain stem. Pseudocysts were not observed in any tissues. Lesions were not found in group 4.

Our results indicated heterogeneity between North American T cruzi isolates in lesion development in dogs, and there appeared to be a temporal relationship between acute and chronic trypanosomiasis in Tc-O- and Tc-A-inoculated dogs and the 3 phases of Chagas disease in human beings.
Evaluation of an enzyme-linked immunosorbent assay for detection of antibodies to vesicular stomatitis virus in cattle in an enzootic region of Mexico
Authors: De Anda Jorge Hernández , Salman M. D. , Webb Patricia A. , Keefe Thomas J. , Arévalo Alejandro Arregín , Mason John
Published: January 2024

An elisa was compared with the plaque-reduction serum neutralization (prsn) test, for detection of vesicular stomatitis virus (vsv) antibodies in cattle in a vesicular stomatitis enzootic region of Mexico. A total of 325 bovine serum samples were screened for vsv antibodies. The prsn test was performed, using Vero cells. The elisa contained gradient-purified vsv Indiana (Lab strain) and vsv New Jersey (Hazelhurst) as the antigens. Regression analysis and weighted kappa statistic were used to estimate measures of agreement between the 2 assays for detection of vsv antibodies. The elisa method proved useful for sero-diagnosis of vesicular stomatitis The elisa and prsn test results were highly correlated for detection of vsv antibodies.
Efficacy of an in-feed preparation of ivermectin against endoparasites and scabies mites in swine
Authors: Primm Nicholas D. , Hall William F. , DiPietro Joseph A. , Bane David P.
Published: January 2024

In 2 trials, the efficacy of an in-feed preparation of ivermectin was evaluated in 40 pigs naturally infected with endoparasites and Sarcoptes scabiei var suis. Treated pigs (n = 10 in each trial) were fed a ration containing 2 ppm ivermectin for 7 days, followed by consumption of a nonmedicated ration for the remainder of the trial. Control pigs (n = 10 in each trial) were fed a complete, nonmedicated ration for the duration of the trial. Pigs in trial A were monitored for 14 days after treatment; those in trial B were monitored for 35 days after treatment.

In trial A, treatment efficacy of ivermectin was 100% against Ascaris suum, Physocephalus sexalatus, Oesophagostomum dentatum, O brevicaudum, Metastrongylus spp; 99.8% against Ascarops strongylina; 90.9% against Trichuris suis; and 13.1% against Macracanthorhynchus hirudinaceus. At the terminus of the trial, statistically significant (P < 0.05) differences were observed between numbers of treated and control pigs infected with A suum, Ascarops strongylina, and Oesophagostomum spp. On posttreatment day 14, S scabiei were not found in any scrapings taken from treated pigs, but were found in scrapings from 3 of 10 control pigs. The number of infested pigs in the treatment group was not statistically different from the number of infested pigs in the control group.

In trial B, treatment efficacy was 100% for A suum and Metastrongylus spp; 96.9% for Ascarops strongylina; and 76.9% for M hirudinaceus. At the terminus of the trial, statistically significant (P < 0.05) differences were evident between numbers of treated and control pigs infected with A suum, Ascarops strongylina, and Metastrongylus spp.

On posttreatment days 7, 21, and 35, S scabiei were not found in scrapings taken from treated pigs. On posttreatment days 7, 21, and 35, S scabiei were found in scrapings from 8, 6, and 1 pig, respectively, whereas live mites were not found on scrapings taken from treated pigs on these days. Statistically significant (P < 0.05) differences were evident between the numbers of infested pigs in the treated and control groups on days 7 and 21.

Ivermectin fed to swine ad libitum in a complete ration at 2 ppm was shown to be highly effective as an anthelmintic and acaricide.
In vivo muscle 31P nuclear magnetic resonance spectroscopy during treatment of halothane-sensitive and halothane-nonsensitive pigs
Authors: Geers Rony , Decanniere Caroline , Villé Hilde , Van Hecke Paul , Goedseels Vic , Vanstapel Flor , Bosschaerts Ludo , De Ley Jef , Zhang Weiguo , Janssens Steven
Published: January 2024

In vivo muscle 31P nuclear magnetic resonance spectroscopy was performed on 10 female pigs originating from a homozygous halothane-sensitive line and on 10 female pigs from a homozygous halothane-nonsensitive line.

The mean concentration of phosphocreatine in the biceps femoris muscle of the anesthetized pigs decreased to 86% of the initial value after 11 minutes of halothane exposure (3%, oxygen flow 3 L/min). After the next 5.6 minutes, phosphocreatine concentration reached a minimal value of 52%, followed by a mean recovery to 76% of the initial value during the ensuing 11 minutes. Response was not observed in anesthetized homozygous halothane-nonsensitive pigs. Thus, a decrease to 86% of the initial value of phosphocreatine was 100% predictive for homozygous halothane-sensitive pigs with body weight ranging from 10 to 18 kg.
Evaluation of granulocytic ehrlichiosis in dogs of Missouri, including serologic status to Ehrlichia canis, Ehrlichia equi, and Borrelia burgdorferi
Authors: Stockham S. L. , Schmidt D. A. , Curtis K. S. , Schauf B. G. , Tyler J. W. , Simpson S. T.
Published: January 2024

Canine granulocytic ehrlichiosis was diagnosed in 37 dogs by finding ehrlichial morulae in 0.1 to 26.2% of their blood neutrophils and eosinophils. All 37 dogs had clinical signs of arthritis or muscular stiffness. Titer to Ehrlichia canis was determined in sera from 31 of the 37 dogs; 25 dogs had titer ranging from 1:20 to 1:5,120. In the other 6 dogs, titer to E canis was <1:10. The most common hematologic abnormality in these dogs, other than rickettsiemia, was thrombocytopenia.

Granulocytes infected with ehrlichial organisms were not found in another 10 dogs that had clinical signs of arthritis or muscular stiffness. Of these 10 dogs, 3 had titer to E canis ranging from 1:40 to 1:320. Titer in the other 7 dogs was < 1:10.

Ehrlichial morulae were not found in the granulocytes of 18 healthy dogs. Of these 18 dogs, 9 had titer to E canis ranging from 1:20 to 1:5,120. Titer in the other 9 dogs was <1:10

Titer to Borrelia burgdorferi was determined in dogs with granulocytic ehrlichiosis, arthritic dogs without detected rickettsiemia, and in healthy dogs. Low titer determined by 2 laboratories was considered to be nonspecific reaction in all 3 groups of dogs and, thus, did not indicate that the arthritic disorders were attributable to canine borreliosis.
Changes in vitreous humor associated with postmortem interval in rabbits
Authors: Henke Scott E. , Demarais Stephen
Published: January 2024

Concentrations of serum and vitreous humor constituents at time of death, and concentrations of vitreous humor constituents at time of death and at 7 postmortem intervals were compared in 70 domestic, female New Zealand White rabbits (Oryctolagus cuniculus). Urea nitrogen concentration was significantly (P = 0.0094) different, but was linearly correlated in serum and vitreous humor at time of death and at the 4- and 8-hour postmortem intervals. Concentrations of γ-glutamyltransferase were not significantly different in serum and vitreous humor at time of death, nor were concentrations significantly different in vitreous humor at time of death and at the 4-hour postmortem interval. The vitreous humor concentrations of glucose, triglycerides, sodium, potassium, cholesterol, total protein, albumin, lactate dehydrogenase, creatine kinase, aspartate transaminase, bilirubin, cortisol, and IgG were neither similar to nor predictive of serum constituents. Vitreous humor can be used as a source for estimates of serum urea nitrogen and γ-glutamyltransferase up to 8 and 4 hours after death, respectively.
Potential attachment area of the first mandibular molar in dogs
Authors: Smith Mark M. , Massoudi Lisa M.
Published: January 2024

Tooth root and root trunk surface area measurements were taken from 20 first mandibular molar (M1) teeth obtained randomly from canine cadaver specimens. The mean root surface area for all teeth was 497.1 ± 116.2 mm2. The cumulative surface areas of the mesial (mr) and distal (dr) roots were 251.4 ± 70.2 mm2 and 211.7 ± 51.9 mm2, respectively. The root trunk surface area was 34.0 ± 21.4 mm2. Surface area measurements for individual roots and the root trunk were significantly different. Cumulative individual root surface area (mr + dr) was 93.2% of total root surface area. The mr surface area contributed most to total root surface area (50.6%) and cumulative individual root surface area (54.3%). The mean distance from the beginning of the root trunk to the furcation was 2.1 mm. On the basis of the linear variation of the percentage of root surface area of the M1, 44.6% of the total root surface area was 3 to 7 mm apical to the most coronal aspect of the cementoenamel junction. The mr was heart-shaped, compared with the more cylindrical shape of the dr.
Analysis of genetic variation of epizootic hemorrhagic disease virus and bluetongue virus field isolates by coelectrophoresis of their double-stranded RNA
Authors: Hammami Salah , Osburn Bennie I.
Published: January 2024

Thirty-two bovine field isolates of bluetongue virus (btv), 6 field isolates of epizootic hemorrhagic disease virus (ehdv) from deer, 4 btv prototype serotypes (10, 11, 13, and 17), and 2 ehdv prototype serotypes (1 and 2) were coelectrophoresed, using polyacrylamide gels. Field isolates were obtained from various regions of the United States. Analysis of polyacrylamide gels and scattered plots generated for comparison of migration patterns for different isolates within each serotype of btv revealed wide variation among the individual segments. The btv serotypes 10 and 11 had more variation, compared with btv serotypes 13 and 17, especially for migration of genome segment 5. A definitive correlation was not seen between the double-stranded rna migration profiles on polyacrylamide gel electrophoresis, geographic origin, herd of origin, or year of collection. One btv field isolate contained more than 1 electropherotype, with 2 bands at the segment-7 position, and it was further characterized as btv serotype 11. Segments 2 and 5 of ehdv isolates were more variable in their migration than were the other gene segments. Generally, migration profiles for ehdv double-stranded rna were more variable, compared with those of btv isolates. Although a correlation was found between migration profiles and serotype of 2 isolates of ehdv, a study of additional ehdv isolates is required before the diversity of electrophoretic patterns of EHDV can be determined.
Sequential development of antigens and toxins of Pasteurella haemolytica serotype 1 grown in cell culture medium
Authors: Confer Anthony W. , Durham Janet A.
Published: January 2024

Pasteurella haemolytica was grown in nonsupplemented cell culture medium, or in medium supplemented with bovine serum albumin (bsa) for 24 hours. The production of leukotoxin (lkt) and endotoxin was sequentially evaluated, as were bacterial antigens associated with bacterial cell lysates and culture supernates. Supplementation of medium with bsa had no effect on bacterial growth curves; however, lkt activity was detected earlier and was greater in culture supernates from bsa-Supplemented media than from nonsupplemented medium. Leukotoxin antigen (105 kDa) was detected in culture supernates, using a monoclonal antibody, immunoblot analysis, and densitometry. The relative concentrations of lkt antigen were proportional to lkt activity. Endotoxin activity was initially lowest in the culture supernates from nonsupplemented medium, but increased during the incubation period, whereas endotoxin activity in bsa-supplemented culture supernates decreased with time in culture. In culture supernates from nonsupplemented medium, the number of antigenic bands identified by immunoblot analysis with hyperimmune anti-P haemolytica and densitometry was greater than in culture supernates from supplemented media. In bacterial lysates, a 95-kDa antigen was the major antigen detected, using the anti-lkt monoclonal antibody. The concentration of that antigen varied among lysates from nonsupplemented medium and bsa-supplemented media. Using hyperimmune anti-P haemolytica serum, minor differences were seen in the relative quantities of lysate-associated antigens dependent on time in culture and medium used. Among the major antigens seen, differences were most apparent for 150-, 100-, and 87-kDa antigens, whereas differences were not obvious for 42-40-, and 30-kDa antigens. In conclusion, at various times in culture, moderate differences were evident in P haemolytica antigens or toxins in bacterial lysates or culture supernates, and the presence of bsa in the medium altered antigenic profiles and toxin concentrations.
Long-term study of aerobic bacteria of the genital tract in breeding bitches
Authors: Bjurström Lena , Linde-Forsberg Catharina
Published: January 2024

The aerobic bacterial flora of the genital tract was characterized in 59 bitches in an 18-month study. The bitches represented 4 breeds and were from 3 kennels. Collection of vaginal swab specimens for bacterial culturing was performed every month, except during estrus when specimens were collected every week (n = 826). The capsule of the swab containing transport media was broken before specimen collection to moisten the tip, which helped to reduce the number of negative cultures. All bitches whelped at least once during the study and, thus, had known reproductive functions. Pregnancy rates, Utter sizes, and pup mortality were within normal limits. Pasteurella multocida, β-hemolytic streptococci group G, and Escherichia coli were the most common bacteria isolated. Although these species generally were isolated from mixed cultures, pure cultures were obtained from 18% of the specimens. There was a tendency for the various breeds to differ in their vaginal bacterial flora. The flora also varied during the reproductive cycle. Pasteurella multocida was isolated significantly more often during proestrus, estrus, metestrus, and pregnancy, than during anestrus and the postpartum period, and β-hemolytic streptococci were isolated significantly more often during proestrus than during estrus, pregnancy, or the postpartum period. Staphylococcus intermedius was almost exclusively found after parturition. Culture results were negative for only 5.2% of specimens cultured. On the basis of our findings, bacterial culturing of vaginal swab specimens from bitches without signs of genital disease is of little value.
Synchronization of estrus in dairy goats given norgestomet and estradiol valerate at various stages of the estrous cycle
Authors: Bretzlaff K. N. , Nuti L. C. , Elmore R. G. , Meyers S. A. , Rugila J. N. , Brinsko S. P. , Blanchard T. L. , Weston P. G.
Published: January 2024

Dairy goats were given subcutaneous implants with 3 mg of norgestomet (nor) and im injections of 0.625 mg of estradiol valerate and 0.375 mg of norgestomet on day 0 of the estrous cycle (estrus; nor 0, n = 18), on postestrus day 4 (nor 4, n = 18), or on postestrus day 11 (nor 11, n = 15). Ear implants were removed after 9 days. Mean (± se) hours from removal of ear implants to onset of estrus and proportion of goats responding were 36 ± 3.8 and 83%, 33 ± 4.0 and 61%, and 36 ± 2.7 and 93% for groups nor 0, nor 4, and nor 11, respectively. There were no significant differences between treatment groups in time to onset of estrus. The percentage of goats in group nor 11 that had signs of estrus was significantly greater than the percentage of goats in group nor 4. Of the goats in groups nor 0, nor 4, and nor 11 that had signs of estrus, 53, 55, and 86%, respectively, had onset of behavioral estrus between 24 and 48 hours after implant removal. All goats that had signs of estrus had onset of behavioral estrus between 12 and 72 hours after implant removal. Mean (± se) hours from removal of ear implants to time of peak concentrations of luteinizing hormone (lh) were 49 ± 4.1, 49 ± 3.8, and 49 ± 4.0 for groups nor 0, nor 4, nor 11, respectively (not different). The percentage of goats in group nor 11 that had lh peaks was significantly greater than the percentage of goats in group nor 4. Of the goats that had estrus, there was no difference between groups in the percentage, which also had an lh peak. On the basis of progesterone profiles from does in group nor 0, functional corpora lutea had formed in 3 of 18 does while the ear implants were in place. In group nor 4, concentrations of progesterone were < 1.0 ng/ml in 6 of 18 does at the time of implant placement, suggesting that these does had not formed functional corpora lutea by postestrus day 4. Eight of 18 does in group nor 4 had concentrations of progesterone > 1.0 ng/ml at 48 hours after implant removal, suggesting that the estradiol valerate in the injection had not prevented the formation of functional corpora lutea after the previous estrus in these animals. All does in group nor 11 had concentrations of progesterone > 1 ng/ml on the day of implant placement. Progesterone concentrations had decreased to < 1 ng/ml in all but 1 doe in group nor 11 by the day of implant removal, suggesting that the corpora lutea from the previous estrous cycle had undergone luteolysis prior to the time of implant removal in most of these animals. This method of synchronization of estrus was effective in dairy goats, although goats that were in the early luteal phase at the time of treatment did not respond consistently.
Seroprevalence of ovine progressive pneumonia virus in sheep in the United States as assessed by analyses of voluntarily submitted samples
Authors: Cutlip Randall C. , Lehmkuhl Howard D. , Sacks Jerome M. , Weaver Amy L.
Published: January 2024

Ovine progressive pneumonia (opp) is a lentivirus-induced disease of sheep in the United States that is similar, if not identical, to maedi/visna in many other countries. Prevalence estimates of seropositivity to this virus in sheep in the United States have been confined to limited groups or flocks of sheep and have varied from 1 to 90%. In this study of detection of antibodies against opp virus, we found a lower general prevalence of antibodies to opp virus in sheep than was previously reported. Of 16,827 sheep from 29 states in the United States, 26% were seropositive and 48% of 164 flocks that were tested had 1 or more seropositive sheep. Seropositivity to opp virus for sheep within special categories was determined, although nonrandom samples that were available may have biased the results. Within regions of the United States, prevalence was highest in the Rocky Mountain region at 49% and lowest in the northern Atlantic region at 9%. Seropositive sheep were not evenly distributed among flocks, but were clustered in a few flocks of sheep. A high number of flocks had no or few seropositive sheep. Prevalence increased with age from 4% at < 1 year to a plateau of 34% at 4 years. Seropositivity was variable among breeds and was not associated with sex, wool class, or place of origin of ancestors.
Antibody response of calves to immunoaffinity-purified bovine respiratory syncytial virus VP70 after vaccination and challenge exposure
Authors: Nelson Lynn D. , Kelling Clayton L. , Anderson Gary A.
Published: January 2024

Immunoaffinity-purified bovine respiratory syncytial virus (brsv) fusion (F) protein elicited anti-brsv-specific antibody responses in brsv-seronegative calves. After primary vaccination, all calves seroconverted to brsv as determined by the virus neutralization (vn) test and developed anti-F protein antibodies detectable by protein immunoblot analyses. Subsequent vaccinations induced > twofold increase in vn titer in 3 of 9 (33%) calves, and 1 calf became vn-negative, but still had nonneutralizing antibody detectable by protein immunoblot analysis. This calf remained seronegative after challenge exposure.

Two groups of calves were vaccinated im with immunoaffinity-purified brsv F protein. Each dose was 2 ml containing 20 μg of purified F protein. Freund's adjuvants were used for all vaccinations, with Freund's complete adjuvant used for the primary vaccination and Freund's incomplete adjuvant for subsequent vaccinations. The vaccine was administered to both groups at weeks 0 and 3; the first group received a third vaccination at week 21. Group-1 and -2 vaccinated calves and non-vaccinated contact controls were intranasally aerosol challenge-exposed with low cell culture-passage brsv on weeks 22 and 9, respectively.

Eight of 9 vaccinated calves did not develop a humoral anamnestic response following challenge exposure, as demonstrated by vn test and protein immunoblot analyses. Calf 14 from group 1 which had a 1:2 vn antibody titer prior to vaccination, was the only calf that developed an anamnestic response. This suggests that vaccine-induced antibodies interfered with the immune response or that the challenge virus (and the virus that calf 14 was infected with before challenge exposure) contained different F protein epitopes, compared with the purified F protein immunogen.
Effects of lung site and fluid volume on results of bronchoalveolar lavage fluid analysis in horses
Authors: Sweeney Corinne Raphel , Rossier Yves , Ziemer Ellen L. , Lindborg Susan
Published: January 2024

Bronchoalveolar lavage (bal) fluid was analyzed in healthy horses, using different lavage fluid volumes and lung sites. The only significant difference in the cellular composition of bal fluid between the right and left lungs was the mast cell numbers, which were significantly higher in the left lung. Total cell count ranged from 34 to 330 cells/μl for the right lung and 43 to 330 cells/μl for the left lung. Percentage of neutrophils ranged from 1 to 7% in the right lung and 1 to 5% in the left lung. The small-volume (50 ml) lavage had a greater percentage of neutrophils and a lesser percentage of mast cells in the large-volume (350 ml) lavage. Statistical difference in the composition of bal fluid recovered was not detected between the 3 sequential 100-ml lavages and a single 300-ml lavage, except that macrophages were significantly higher in the 3 sequential 100-ml lavages. Values for bal fluid analysis in healthy horses have varied considerably and this variation is from a failure to adhere to any standard technique for volume of fluid infused.
Concurrent experimentally induced infection with Eimeria bovis and coronavirus in unweaned dairy calves
Authors: Hoblet Kent H. , Shulaw William P. , Saif Linda J. , Weisbrode Steven E. , Lance Susan E. , Howard Richard R. , Angrick Elisabeth J. , Redman Donald R.
Published: January 2024

Over a period of 3 summers, 21 colostrum-fed Holstein bull calves, 1 to 3 days old, were assigned to 7 replicates, each consisting of 3 calves. Within each replicate of 3 calves, 2 were selected at random, to be given 100,000 to 146,000 sporulated coccidia oocysts (principally Eimeria bovis) orally 60 hours after arrival at the college research farm. On the thirteenth day after coccidia inoculation, 1 of the 2 calves that had been given coccidia and the third calf that had not been inoculated, were given coronavirus by intranasal and oral routes. Calves were observed daily, and consistency of feces was scored visually. Nasal swab specimens for indirect immunofluorescent antibody testing for coronavirus and fecal samples for oocyst determination were obtained approximately every third day. Of 7 calves that were given only coronavirus, 3 developed diarrhea of short duration. Of 7 calves that were given only coccidia oocysts, 6 developed diarrhea. All 7 calves inoculated initially with coccidia and subsequently with coronavirus developed diarrhea. For 5 of 7 replicates, calves that were given coccidia and coronavirus developed diarrhea first. When overall severity, measured by fecal score and by blood in the feces, was compared, calves inoculated with coccidia followed by coronavirus were more severely affected (P < 0.05) than were calves that were given only coronavirus. Calves that were given only coccidia oocysts appeared more severely affected than calves that were given only coronavirus, but differences were not significant. Calves that were given either coccidia alone, or coccidia followed by coronavirus, had more severe lesions of mucosal degeneration/epithelial necrosis and inflammation (P < 0.05) than did calves that were given only coronavirus. Lesions, however, were generally most severe in calves that were given coccidia and coronavirus. In 4 calves, fibrinopurulent typhlitis and/or colitis were observed; 3 of these observations were made in calves that were given coccidia followed by coronavirus. These observations indicate that, although coronavirus infection in young calves is common and may be mild in calves given adequate colostrum, when combined with coccidia (principally E bovis) infection, resultant clinical signs of disease and lesions may be more severe than those associated with infection attributable to either coronavirus or coccidia alone.
Histochemical and immunohistochemical study of the mucosal lymphoid system in swine
Authors: Ramos José A. , Ramis Antonio J. , Marco Alberto , Domingo Mariano , Rabanal Rosa , Ferrer Luis
Published: January 2024

Enzyme histochemical and immunohistochemical techniques were used to examine palatine tonsils and aggregated lymphoid follicles (Peyer's patches) of the ileum in 6- to 9-day-old and in 6-month-old pigs. Histochemical techniques were used to detect α-naphthyl-acetate esterase (anae), α-naphthyl-butyrate esterase (anbe), β-glucuronidase, adenosine triphosphatase (ATPase), and acid phosphatase (AcP). Nonspecific esterases (anae, anbe) were detected in macrophages, T-cell area lymphocytes, eosinophils, fibroblastic reticular cells (frc), follicular dendritic cells (fdc), and interdigitating cells (idc). β-Glucuronidase reactivity was strong in macrophages, eosinophils, fdc, and idc, and weaker in frc. Adenosine triphosphatase reactivity was detected in B-cell area lymphocytes, fdc, frc, and idc. Cell types with acid phosphatase reactivity were macrophages, fdc, frc, and idc. Nonepithelial cells of tonsils and aggregated lymphoid follicles of the ileum had similar enzymatic reactions. In Peyer's patches, however, epithelial cells were positive for all enzymes studied; in tonsils, only nonspecific esterases were detected. Immunoperoxidase techniques were used to detect S-100 protein and cytoplasmic immunoglobulins (IgG, IgM, and IgA). The S-100 protein was detected in lymphocytes, fdc, and frc of tonsils and Peyer's patches; in tonsillar epithelial and endothelial cells; and in idc of Peyer's patches. Cytoplasmic immunoglobulins were detected in lymphoblastoid and plasmacytoid cells of follicles and diffuse lymphoid tissue in both organs and in ileal epithelial cells. Compared with those of 6-month-old pigs, cells of 6- to 9-day-old pigs stained less intensely by all enzyme histochemical techniques, and fewer cells were reactive for immunoglobulins.
Osmotic stress in red blood cells from Beagles with hemolytic anemia
Authors: Pekow Cynthia A. , Hinds Thomas R. , Maggio-Price Lillian , Hammond William P. , Vincenzi Frank F.
Published: January 2024

Red blood cell populations separated by density centrifugation were compared in a dynamic assay of osmotic stress. Red blood cells from Beagles genotypically normal and nonanemic (nonaffected), Beagles with inherited hemolytic anemia (anemic), and Beagles presumed to be carriers of the anemia trait (trait carriers) were examined for rate and extent of swelling after exposure to the ionophore A23187 in a medium containing calcium and potassium chloride. Comparisons were made between rbc populations separated on the basis of density. Significant differences were observed in the rates of cell swelling in rbc populations separated by density between nonaffected and anemic Beagles. The response of rbc from Beagles presumed to carry the anemia trait was similar to that of rbc from nonaffected dogs. One phenotypic expression of this inherited abnormality of rbc in Beagles was an accelerated rate of rbc swelling under osmotic stress, and this swelling response diminished with increasing rbc density.
Function of neutrophils and chemoattractant properties of fetal placental tissue during the last month of pregnancy in cows
Authors: Hoedemaker Martina , Lund Lisa A. , Wagner William C.
Published: January 2024

Neutrophils were isolated from the blood of pregnant cows on days 255, 265, and 275 of pregnancy, and on the day of parturition (n = 5/group), and in addition, simultaneously from 4 ovariectomized healthy cows (control animals). Neutrophils were subjected to neutrophil function assays (chemotaxis against zymosan-activated serum, random migration, ingestion of 125I-iododeoxyuridine [IdUR]-labeled Staphylococcus aureus, iodination of proteins, cytochrome C reduction, antibody-independent and antibody-dependent cell-mediated cytotoxicity). Results were expressed as percentage of control animals. Fetal placental tissue (cotyledon), uterine wall tissue, and skeletal muscle were obtained from the principal animals on the aforementioned days via laparotomy, and tissue suspensions were prepared. Chemotaxis of neutrophils was tested against tissue supernatants. Compared with day 255, there was an increase in ingestion of 125I-IdUR-S aureus at parturition, whereas iodination of proteins and cytochrome C reduction were reduced on the day of calving. The other neutrophil functions tested did not change over time of gestation. Fetal placental and uterine wall tissue attracted neutrophils with uterine wall tissue having a tendency to be more potent than cotyledonary tissue. Skeletal muscle tissue did not attract neutrophils. There was no change in chemotaxis response of neutrophils evoked by intrauterine and uterine tissues over time of gestation. It was concluded that at parturition, neutrophil function is impaired with respect to their bactericidal effects, which may render the animal more susceptible to bacterial infections, and that the chemoattractant properties of fetal placental and uterine wall tissues are tissue-specific, at least when compared with skeletal muscle. The presence of neutrophils in the placenta and other parts of the uterus may be necessary for placental separation and prevention from postpartum intrauterine bacterial infections, respectively.
Computer-based collection and analysis of myoelectric activity of the intestine in horses
Authors: Lester G. D. , Bolton J. R. , Thurgate S. M.
Published: January 2024

Extracellular myoelectric activity from the terminal ileum cecum, and colonic pelvic flexure was assessed in 4 adult horses. The collection and analysis of myoelectric data involved the development and use of a computer-based system. After collection, the myoelectric signal was digitally filtered to enhance the activity of interest. The smoothed signal was then processed by use of computer programs designed to identify and count spike-burst activity and estimate burst duration. The intense phases of myoelectric complexes also were identified. The propagation of myoelectric spike-burst activity was assessed over 3 electrode sites to identify the propagative patterns of intestinal motility. There was high correlation between the results of computer-based analysis and those of visual analysis. We concluded that the computer provides a fast, accurate, and reliable means of assessing myoelectric activity.
Fate and effect of autogenous osteochondral fragments implanted in the middle carpal joint of horses
Authors: Huber Michael J. , Schmotzer Wayne B. , Riebold Thomas W. , Watrous Barbara J. , Synder Stanley P. , Scott Edward A. , von Matthiessen Pamela C.
Published: January 2024

Four autogenous osteochondral fragments removed from the lateral trochlear ridge of the talus were arthroscopically placed as loose bodies in a randomly selected middle carpal joint in each of 10 horses. The contralateral middle carpal joint, subjected to a sham procedure, served as control. Postoperative treatment was consistent with that for clinical arthroscopic patients. Lameness evaluation, radiographic examination, carpal circumference measurement, and synovial fluid analysis were performed before and at scheduled intervals after surgery. After a 2-month confinement, horses were subjected to an increasing level of exercise. Horses were euthanatized at intervals through 6 months. Gross and microscopic evaluations were performed on remaining fragments, articular cartilage, and synovial membrane of each middle carpal joint.

Increased joint circumference, effusion, lameness, and degenerative joint disease distinguished implanted from control joints over the 6-month period. Implanted joints were characterized by grooved, excoriated cartilage surfaces, and synovium that was thick, erythematous, and irregular. At 4 weeks, implants were found to have adhered to synovium at their subchondral bone surface. The bone within fragments was undergoing necrosis, while cartilage was preserved. At 8 weeks, fragments were radiographically inapparent, grossly evident as pale plaques on the synovial surface, and composed of dense fibrous connective tissue.

Synovial membrane specimens from implanted joints had inflammatory change characterized by mononuclear cell infiltration 2 months after implantation. Physical damage was apparent within articular cartilage of implanted joints at 2 months, and was significant (P < 0.05) at 6 months after surgery. Chondrocyte degenerative change was significant (P < 0.05) at 6 months after surgery. Focal reduction in safranin-O uptake was observed in cartilage layers adjacent to physical defects.

Osteochondral loose bodies of the size implanted in the middle carpal joint of horses in this study were resorbed by the synovium within 2 months. Synovitis and significant articular cartilage damage were associated with the implanted fragments. Regardless of origin, free osteochondral fragments within the middle carpal joint should be removed, and methods to prevent residual postoperative debris should be implemented to reduce potential for articular pathologic change.
Long-term cannulation of the ovarian vein in mares
Authors: Linford Robert L. , McCue Patrick M. , Montavon Stephane , Lasley Bill L.
Published: January 2024

A cannulation technique was developed to collect blood samples from the ovarian vein of mares over an extended period. Ovarian venous cannulae placed in 4 mares remained patent for a mean (± sem) duration of 36.8 (± 6.2) days. During mid-diestrus, concentrations of progesterone in the ovarian vein ipsilateral to the corpus luteum (1,663.8 ± 238.8 ng/ml) were significantly (P < 0.001) higher than concentrations measured in paired samples from the jugular vein (6.1 ± 0.3 ng/ml). Concentration of estradiol in the ovarian vein ranged from a mean of 1,053.2 ± 303.1 pg/ml during diestrus to 3,353.8 ± 1,052.8 pg/ml during estrus, whereas values for 74% of samples collected concurrently from the jugular vein were near or below the sensitivity of the assay (10 pg/ml).

Results of the study indicate that patent long-term ovarian vein cannulation can be achieved in mares. The cannulation technique provides access to important fundamental information on equine reproductive endocrinology, which to our knowledge, has not been available.
Use of end-tidal CO2 tension to predict arterial CO2 values in isoflurane-anesthetized equine neonates
Authors: Geiser Dennis R. , Rohrbach B. W.
Published: January 2024

End-tidal carbon dioxide tension (PetCO2) and arterial carbon dioxide tension (PaCO2) were determined and compared in isoflurane-anesthetized spontaneously breathing equine neonates. End-tidal carbon dioxide and PaCO2 values increased with respect to time. Difference between values of PetCO2 and PaCO2 increased over time. End-tidal carbon dioxide tension was useful to predict changes in and was more closely correlated with PaCO2 early in the anesthetic period (T ≤ 60 minutes). The dead space volume to tidal volume (Vd/Vt) ratio increased with respect to time, indicating increase in physiologic dead space in isoflurane-anesthetized foals. The data indicate that the increased difference between widening of the PetCO2 and PaCO2 values over time may have been attributable to hypoventilation and decreased pulmonary capillary perfusion of alveoli.