bluuebunny/crossref_metadata_2025 huggingface dataset:
M-mode echocardiographic values in sheep
Authors: Moses Bradley L. , Ross James N.
Published: February 2025

M-mode echocardiograms were recorded from 21 adult sheep (20 ewes, 1 whether). Fifteen echocardiographic measurements were taken and compared with body weights or heart rates, using linear regression equations. Significant correlations (P < 0.05) were found when body weight was compared with left ventricular internal dimensions in systole (Yo = 0.187 Xo + 18.60, P < 0.05) and diastole (Yo = 0.346 Xo + 26.69, P < 0.02), septal thickness in systole (Yo = 0.0876 Xo + 7.64, P < 0.05) and diastole (Yo = 0.0673 Xo + 4.45, P < 0.05), aortic root dimension (Yo = 0.129 Xo + 23.40, P < 0.05), and left atrial dimension (Yo = 0.194 Xo + 15.95, P < 0.005). Heart rate was significantly correlated (P < 0.05) with body weight (Yo = −0.245 × 96.71, P < 0.05), ejection time (Yo = −0.0013 Xo + 0.376, P < 0.001), velocity of circumferential fiber shortening (Yo = 0.0061 Xo + 0.928, P < 0.05), mean velocity of mitral valve middiastolic closure (Yo = 0.184 Xo + 1.65, P < 0.02), and left atrial dimension (Yo = -0.109 + 40.55, P < 0.005). Fractional shortening of the left ventricle was (mean) 37.2 ± 5.7% and the left atrial to aortic root ratio was (mean) 0.92 ± 0.10.
Use of viable-cell ELISA for detection of monoclonal antibodies recognizing tumor-associated antigens on bovine lymphosarcoma cells
Authors: Aida Y. , Onuma M. , Kasai N. , Izawa H.
Published: February 2025

An elisa, using viable bovine lymphosarcoma cells, was developed to detect tumor-associated antigens (taa) expressed on lymphosarcoma cells from cows with enzootic bovine leukosis (ebl). Monoclonal antibodies (mab) against taa were used. Using viable-cell elisa, mab reacted with tumor cells from 9 cows with ebl, but not with peripheral blood lymphocytes from 10 clinically normal cows. Titers of mab against tumor cells from 1 cow with ebl were 2,048 (direct immunofluorescence assay), 8,192 (flow cytometry), 2,048 (fixed-cell elisa), and 16,384 (viable-cell elisa). Viable-cell elisa was the most sensitive method for detection of taa. Reactivities of 7 mab to tumor cells from cows with ebl were compared between viable-cell elisa and a complement-dependent antibody cytotoxicity test. Of 5 mab with no cytotoxic activity against tumor cells, 3 were reactive against tumor cells from the same cow, as determined by viable-cell elisa, with titers ranging from 128 to 2,048.
Serum ferritin, serum iron, and erythrocyte values in foals
Authors: Harvey John W. , Asquith Richard L. , Sussman Wendy A. , Kivipelto Jan
Published: February 2025

Twenty-one healthy Thoroughbred and Quarter Horse foals were studied from birth until 1 year of age. Foals had access to an iron-supplemented creep feed before weaning and were fed an iron-supplemented concentrate as part of their diet after weaning at 4 months of age. Initial blood samples were taken before foals were allowed to nurse. Serum iron concentration, total iron-binding capacity, and pcv decreased during the foal's first 24 hours of life. Serum iron concentration decreased rapidly from 446 ± 16 μg/dl (mean ± se) at birth to 105 ± 11 μg/dl at 3 days of age. Serum ferritin concentration increased from a mean of 85 ± 8 ng/ml at birth to 159 ± 11 ng/ml at 1 day of age. Thereafter, ferritin concentration decreased gradually to a minimum of 61 ± 6 ng/ml at 3 weeks of age, and then at 6 months increased to values similar to those from reference adult horses. The ferritin concentration in colostrum at birth was 354 ± 42 ng/ml, compared with 25 ± 2 ng/ml in milk 1 day later. The decrease and then increase in serum ferritin concentration occurred concomitantly with opposite changes in serum total iron-binding capacity. The mean pcv decreased gradually to a minimum at 3 months of age. This decrease was associated with an increasing number of microcytes, as determined with a cell-size distribution analyzer.
Failure of passive immunoglobulin transfer: A major determinant of mortality in newborn alpacas (Lama pacos)
Authors: Garmendia Antonio E. , Palmer Guy H. , DeMartini James C. , McGuire Travis C.
Published: February 2025

Failure of passive transfer (fpt) of immunoglobulin from colostrum was demonstrated as a major determinant of mortality in newborn alpacas (Lama pacos; crias). Serum IgG concentrations of dying crias were significantly (P < 0.0001) lower than were serum IgG concentrations of crias that lived. Of 82 crias, 10 (12%) died within 1 month of age, and 7 of these had 0 to 9 mg of IgG/ml of serum at 48 hours after birth; 5 of the 7 had evidence of infectious diseases. The serum IgG concentrations of the remaining dead crias were 12, 13, and 20 mg/ml. On the basis of serum IgG concentrations of crias that died in the first month, fpt was defined as a 48-hour serum IgG concentration < 9 mg/ml, which was > 2 SD below the 48-hour mean of clinically normal crias. Using this definition, the prevalence of fpt in the 82 crias studied was 9%.

Corroborative evidence of the relationship between fpt and mortality was obtained from a retrospective study of 21 dead crias. The postmortem serum IgG concentration of 5 crias that died 2 to 10 days after birth ranged from < 1 to 3 mg/ml; all were > 2 SD below the mean of age matched clinically normal crias. The range of serum IgG concentration was 2.2 to 21 mg/ml in 8 crias that died 11 to 20 days after birth; serum IgG concentration in 1 cria was > 2 SD below the normal mean, and 6 were > 1 SD below the normal mean. Eight crias that died 21 to 30 days after birth had serum IgG concentrations ranging from 7 to 37 mg/ml; 3 were > 1 SD below the normal mean. Histologic lesions compatible with infections were present in 19 of 21 dead crias.
Listeriosis in diacetoxyscirpenol-treated mice
Authors: Ziprin Richard L. , Corrier Donald E.
Published: February 2025

Mice were treated with the trichothecene mycotoxin diacetoxyscirpenol (das) and subsequently were inoculated intraperitoneally with Listeria monocytogenes. The effect of the mycotoxin on the course of the infection was monitored by observing the resultant mortality and the bacterial content of the spleens from inoculated mice. Mice given 3 mg of das/kg of body weight, po, at days -2 and -1 before inoculation had increased mortality and splenic Listeria counts. In these mice, thymus weights were reduced, and lymphocytes were depleted from the thymus cortex and from splenic lymphoid follicles and periarte-riolar lymphoid sheaths. A single dose of 4 mg of das/kg given on day 6 before challenge exposure did not affect mortality compared with that in nontreated controls. Mice treated with das and subsequently inoculated with Listeria had significantly (P = 0.006) increased neutrophil populations compared with Listeria-mfected control mice.
Growth-stimulating substances in porcine milk
Authors: Jaeger L. A. , Lamar C. H. , Bottoms G. D. , Cline T. R.
Published: February 2025

Colostral and milk samples were collected from 6 primiparous sows on postpartum days 0, 9, 18, and 27. Insulin content was measured and epidermal growth factor (egf) concentration was determined by use of radioimmunoassay and radioreceptor assay, respectively. Total milk protein concentration was measured colorimetrically. Concentrations of insulin, egf, and protein in the colostral samples were significantly (P < 0.01) higher than those found in the milk. Milk samples obtained from postpartum days 9, 18, and 27 did not differ significantly in insulin, egf, or total protein content.
Influence of Bordetella avium infection on association of Escherichia coli with turkey trachea
Authors: Van Alstine W. G. , Arp L. H.
Published: February 2025

Four-week-old Bordetella avium-infected and B avium-free turkeys were inoculated intratracheally with a suspension of fimbriated or nonfimbriated Escherichia coli. Numbers of E coli associated with tracheal sections were determined at postinoculation hour (pih) 1 or 6. Significantly (P < 0.05) greater numbers of E coli were isolated from the tracheas of B avium-infected turkeys compared with numbers in B avium-free turkeys. In B avium-free turkeys, tracheal associated E coli were 90% less at pih 6 compared with that at pih 1. However, in B avium-infected turkeys, numbers of E coli were not affected by postinoculation time. Seemingly, B avium-infected turkeys had reduced capacity to clear E coli from the trachea.
Induced pasteurellosis and pulmonary vascular adrenoceptor function in bull calves
Authors: Greenlees Kevin J. , Shewen Pat , Yager Julie , Eyre Peter
Published: February 2025

Effects of Pasteurella haemolytica inoculation on pulmonary vascular function were studied in 5 conscious standing Jersey bull calves. Instruments were implanted in each calf to measure pulmonary arterial, pulmonary arterial wedge, left atrial, and systemic arterial pressures and cardiac output. Each calf was challenge exposed with 5 sequential 3-minute infusions of isoproterenol (a β agonist) or phenylephrine (an α agonist) for maximal doses of 1.8 μg of isoproterenol or 2.3 μg of phenylephrine/kg of body weight/min. The calf was allowed 1 hour to recover, was anesthetized, and administered a 20-ml intratracheal infusion of live P haemolytica (106 colony-forming units/ml) followed by a 20-ml saline flush. The pulmonary hemodynamic response to isoproterenol and phenylephrine was examined again in each calf 4 days later.

Calves developed a pneumonic pasteurellosis involving 26 to 43% of the lungs. There was a significantly (P < 0.05) reduced resistance in the pulmonary arterial compartment after inoculation. Isoproterenol infusion decreased resistance in the pulmonary arterial, pulmonary venous, and systemic vascular compartments. The decrease in the pulmonary venous compartment in response to isoproterenol was significantly (P = 0.01) smaller after P haemolytica inoculation. After administration of 1.8 μg of isoproterenol/kg/min, resistance in the pulmonary venous compartment was 0.90 ± 0.22 (mean ± SD) before and 1.25 ± 0.39 after Pasteurella inoculation. Phenylephrine resulted in an increase in pulmonary arterial, pulmonary venous, and systemic vascular compartments. There was a mild (P = 0.08) decrease in the pulmonary arterial compartment response to phenylephrine. Seemingly, Pasteurella inoculation blunted β-receptor function in the pulmonary vascular bed, mainly in the veins, contributing to edema.
Management of twin conceptuses by manual embryonic reduction: Comparison of two techniques and three hormone treatments
Authors: Pascoe David R. , Pascoe Reginald R. , Hughes John P. , Stabenfeldt George H. , Kindahl Hans
Published: February 2025

One hundred mares carrying twin conceptuses between gestation days (gd) 12 and 30 were assigned to 4 groups. Group-1 mares (n = 20) were given a placebo (sterile saline solution, iv, and sesame oil, im). Group-2 mares (n = 32) were given a single dose of progesterone (625 mg, im) in sesame oil. Group-3 mares (n = 28) were given multiple progesterone treatments (625 mg, im) at 6-day intervals until gd 42. Group-4 mares (n = 20) were given a single treatment of flunixin meglumine (500 mg, iv) and progesterone (625 mg, im). Each group was further assigned to equal subgroups A and B according to the age of the embryos. In subgroup A, with embryos at gd 12 to 16, embryonic vesicle rupture was performed after the selected conceptus was moved to the tip of a uterine horn. In subgroup B, with embryos at gd 17 to 30, embryonic vesicle rupture was performed on the selected conceptus in situ. An additional 6 mares carrying single conceptuses (gd 12, 14, 16, 20, 25, and 30) were used as subjects for sham embryonic vesicle rupture.

Both rupture techniques usually caused the release of prostaglandin (pg)F2α for up to 90 minutes. Amounts of pgf2α were directly correlated with the pressure required to efffect embryonic vesicle rupture. Sham embryonic vesicle rupture attempts caused small pgf2α releases after each manipulation, which rapidly returned to basal values. All 6 mares were still pregnant at gd 42. Flunixin meglumine inhibited pgf2α release after embryonic vesicle rupture, regardless of the technique. Survival rates for the remaining conceptus were 100% for group 1A (10 of 10), 100% for group IB (10 of 10), 100% for group 2A (16 of 16), 94% for group 2B (15 of 16), 86% for group 3A (12 of 14), 93% for group 3B (13 of 14), 100% for group 4A (10 of 10), and 100% for group 4B (10 of 10). Thus, embryo removal can be accomplished in the mare without effect on the remaining embryo if the technique (embryonic vesicle per rectum) is done before gd 30. Administration of exogenous progesterone or flunixin meglumine was not essential for maintaining viability of the remaining conceptus.
Efficacy of ivermectin against the abomasal nematode Mecistocirrus digitatus in naturally infected zebu calves
Authors: Mendoza-de Gives Pedro , Fuentes Rodolfo Nájera , Herrera-Rodríguez David , Roncalli Raffaelle A.
Published: February 2025

Anthelmintic efficacy of ivermectin against Mecistocirrus digitatus was evaluated in 10 naturally infected zebu calves. Group 1 (n = 5) was not treated, and group 2 (n = 5) was treated sc with 200 μg of ivermectin/kg of body weight. Calves were euthanatized 14 or 15 days after treatment. There was 100% overall reduction of M digitatus in treated calves, which was significant (P = 0.0079) compared with reduction in controls. Cooperia punctata, Haemonchus similis, and Trichostrongylus axei were found in controls. Efficacy against these parasites in treated calves was 100%.
Efficacy of sulbactam-ampicillin in an induced Pasteurella haemolytica pneumonia model in calves
Authors: Farrington Daniel O. , Jackson James A. , Bentley O. Eugene , Barnes H. John
Published: February 2025

Therapeutic efficacy of sulbactam, a β-lactamase inhibitor, in combination with ampicillin was evaluated in an ampicillin-resistant Pasteurella haemolytica pneumonia model in cattle, using an iv agar emboli method of infection. Groups of cattle given vehicle (group 1, n = 19) or ampicillin (group 2, n = 8) had 74% and 50% mortality, respectively, whereas group 3 (n = 11) given sulbactam-ampicillin had no mortality. Morbidities were 100% in groups 1 and 2 and 27% in group 3. Retrospectively, mortalities and morbidities were significantly (P < 0.001) lower for group 3 given sulbactam-ampicillin when compared with those in groups 1 and 2 given vehicle or ampicillin, respectively. Evidence of embolic pneumonic pasteurellosis was observed histologically.
Effect of anticholinergic preanesthetic medicaments on the requirements of halothane for anesthesia in the cat
Authors: Webb A. I. , McMurphy Rose M.
Published: February 2025

To study the effects of anticholinergics on anesthetic requirements, minimal alveolar concentrations (mac) for halothane in the cat were measured before and after im administration of an anticholinergic (atropine sulfate [0.045 mg/kg], glycopyrrolate [0.011 mg/kg], or scopolamine hydrobromide [0.02 mg/kg]) or a physiologic saline control. The study was performed in 8 adult cats, using a randomized-block experimental design. There was no significant difference between the mean mac obtained before and after administration of any of the test drugs or vs the control values. The mean mac of halothane in cats was 0.985% atmosphere.
Spinal nerve root origins of the cutaneous nerves of the canine pelvic limb
Authors: Bailey Cleta Sue , Kitchell Ralph L. , Haghighi Siavash S. , Johnson Richard D.
Published: February 2025

The spinal nerve root origins of the cutaneous nerves innervating the canine pelvic limb were determined in 12 barbiturate-anesthetized, healthy dogs by stimulating the dorsal roots L1-S3 and recording the evoked-action potentials from each cutaneous nerve. The dogs were then euthanatized, identification of each dorsal root and cutaneous nerve was verified by dissection, and the type of lumbosacral plexus (prefixed, median fixed, or postfixed) was determined.

With one exception, the dorsal cutaneous branches and lateral cutaneous branches of L1-L3 originated only from their corresponding spinal nerve roots. The genitofemoral nerve received afferent fibers predominantely from L3-L4 nerve roots. The lateral cutaneous femoral nerve originated from L3-L5 nerve roots, and the saphenous nerve from L4-L6 nerve roots. The proximal caudal cutaneous sural nerve originated from L6-S1. The lateral cutaneous sural nerve originated from L5-S1; the deep and superficial fibular nerves arose primarily from L6-L7. The distal caudal cutaneous sural nerve originated predominantly from L7-S1, and the medial cutaneous tarsal nerve originated from L6-S1. The medial plantar nerve originated predominantly from L6-S1 roots, whereas the lateral plantar nerve originated from L6-S2 roots. The middle clunial nerve received afferent fibers primarily from Sl-S2; the caudal clunial nerve received fibers from S1-S3. The caudal cutaneous femoral nerve originated predom-inantly from L7-S2. The dorsal nerve of the penis originated predominantly from S1-S2, and the superficial perineal nerve originated from S1-S3.

One dog had a prefixed plexus, 8 dogs had median-fixed plexuses, and 1 dog had a postfixed plexus. The plexus type of 2 dogs could not be determined because of dissection damage. The nerve root origins of the cutaneous nerves were not consistently related to plexus type.
Pharmacokinetics of intravenously and intramuscularly administered ticarcillin and clavulanic acid in foals
Authors: Sweeney Raymond W. , Beech Jill , Simmons Robert D.
Published: February 2025

Serum concentrations of ticarcillin and clavulanic acid were measured in healthy foals (2 to 6 months old) given the drugs in combination by intravenous and intramuscular routes of administration.

Five foals were administered 50 mg of ticarcillin/kg of body weight and 1.67 mg of clavulanic acid/kg, iv. Five foals were administered 100 mg of ticarcillin/kg and 3.33 mg of clavulanic acid/kg, iv, and 4 of those 5 were given the same combined dose im.

The elimination half-life of ticarcillin for intravenous administration was 0.83 hour for the low dosage and 0.96 hour for the high dosage. After intramuscular administration, the half-life of elimination was 2.9 hours, with bioavailability of 54.6%.

For iv administered clavulanic acid, the elimination half-life was 0.65 hour for the low dosage and 0.74 hour for the high dosage. After intramuscular administration, the elimination half-life was 0.92 hour, and bioavailability was 68.1%.

A combined dosage, 50 mg of ticarcillin/kg and 1.67 mg of clavulanic acid/kg, given every 6 hours is recommended.
Pharmacokinetics of chlortetracycline in the turkey: Evaluation of biliary secretion
Authors: Dyer D. C.
Published: February 2025

The pharmacokinetics of chlortetracycline (ctc) in plasma and bile after intravenous administration in turkeys was ascertained. After a dose of ctc (0.9 mg/kg) was administered iv, 8.5% of the dose appeared in the bile in 4 hours. The peak bile/plasma concentration ratio for ctc was 254 at 2 hours. The bile/plasma concentration ratio was > 1 from 10 to 240 minutes after ctc administration.
Development and evaluation of an enzyme-linked immunosorbent assay for bovine antibody to Pasteurella haemolytica: Constructing an enzyme-linked immunosorbent assay titer
Authors: Sacks J. M. , Gillette K. G. , Frank G. H.
Published: February 2025

A 2-stage strategy was developed and evaluated for estimating serum antibody titer by use of elisa and a series of dilutions. In stage 1, the linear response region and least-square estimate of the assay line slope were established from 9-point dilution assays. Provided that the reading was within the linear response region, this information was used in the stage-2 estimation of titer from a single absorbance reading. Operationally, 2 fixed dilutions were selected, one suitably low and one suitably high, to provide at least one reading within the linear region. The procedure should save considerable time when a large number of assays are to be performed. Stage 1 required approximately twenty 9-point assays, but all subsequent assays required only 2 fixed dilutions.
Relationship between immunoglobulin concentrations in milk and phagocytosis by bovine neutrophils
Authors: Miller R. H. , Guidry A. J. , Paape M. J. , Dulin A. M. , Fulton L. A.
Published: February 2025

Using bovine neutrophils and radio-labelled Staphylococcus aureus, skim milk samples taken at 4 stages of lactation from the 4 mammary quarters of 48 cows were used in an in vitro phagocytosis assay. Immunoglobulin (Ig) isotype concentrations in the milk samples were estimated by use of an elisa procedure. To determine associations of Ig concentrations with phagocytosis, correlations, simple regressions, and partial regressions were calculated. Simple correlations were computed between each Ig isotype and phagocytosis percentage for each lactation number stage of lactation category. Ranges of these correlations for IgM, IgG1, IgG2, and IgA were 0.33 to 0.60; -0.16 to 0.43; 0.04 to 0.46; and -0.30 to 0.36, respectively. Correlations for concentrations of IgG2 and IgM with percentage of phagocytosis tended to be slightly higher for samples from older cows, in contrast to the correlations calculated for IgA and IgG1. Multiple regression of percentage of phagocytosis calculated simultaneously on concentrations of the 4 Ig isotypes in the sample indicated that IgM, followed by IgG2 and IgA, was most closely associated with phagocytosis. Partial regression calculated on concentration of IgG1 was not significant. Addition of bacteriologic status of the quarter and somatic cell concentration in the milk sample did not increase accuracy of predicting percentage of phagocytosis, compared with use of Ig concentrations alone. These results supported the attribution of unique modes of action to IgM and IgG2 in promoting phagocytosis by neutrophils.
Expression of metabolism-inhibition antibodies against Mycoplasma arthritidis in rats
Authors: Washburn Leigh Rice , Cole Barry C. , Ward John R.
Published: February 2025

Shared antigens between Mycoplasma arthritidis and rat tissues may be responsible for the lack of metabolism-inhibition (mi) and other neutralizing antibodies in rats with M arthritidis-induced arthritis. We were not able to confirm such shared antigens or to detect cross-reacting antigens between M arthritidis and rat lymphocytes, thymocytes, and muscle tissue. Antisera of rabbit origin to rat lymphocytes, thymocytes, and skeletal muscle reacted by elisa with M arthritidis only when the mycoplasmal antigens were prepared from organisms grown in medium containing horse serum. Such activity could be completely absorbed by horse serum. These antisera to rat tissues also failed to react by radioimmunoprecipitation with M arthritidis surface antigens. In addition, antibody activity against homologous antigens could not be absorbed by M arthritidis. Similarly, antisera of rabbit origin against M arthritidis failed to react by elisa specifically with rat lymphocytes, thymocytes, and skeletal muscle or to react by radioimmunoprecipitation with 125I-labeled rat lymphocyte antigens. These rat tissues could not specifically absorb antibodies against M arthritidis from antisera of rabbit origin. These findings suggest that the lack of mi antibodies in rats probably can not be explained by rat tissue antigens that cross-react with M arthritidis mi antigens. Finally, antisera of rat origin against M arthritidis and other rat tissue components failed to block rabbit mi activity against M arthritidis, thus arguing against steric hindrance as a means of preventing recognition of mi antigens.
Adherence of Haemophilus somnus to bovine embryos after in vitro exposure
Authors: Thomson M. S. , Stringfellow D. A. , Lauerman L. H.
Published: February 2025

Preimplantation bovine embryos were exposed in vitro to Haemophilus somnus to determine whether the bacteria would adhere to zona pellucida-intact embryos or would adhere to or infect zona pellucida-free embryos. The effect of H somnus on in vitro embryonic development also was investigated. After exposure to H somnus and before washing, some of the zona pellucida-intact embryos were held in antibiotic-containing medium. Haemophilus somnus was isolated from 10 of 42 zona pellucida-intact embryos and none of the zona pellucida-free embryos. Haemophilus somnus was not recovered from any of the 32 antibiotic-treated embryos. The coculture system was not compatible with normal embryonic development, and all embryos had begun to degenerate by the end of the 18-hour exposure period.
Chronic flunixin meglumine therapy in foals
Authors: Traub-Dargatz J. L. , Bertone J. J. , Gould D. H. , Wrigley R. H. , Weiser M. G. , Forney S. D.
Published: February 2025

Effects of a therapeutic dose of flunixin meglumine on gastric mucosa of horse foals were determined by endoscopy, double-contrast radiography, and gross and histologic examinations. Foals were administered 1.1 mg of flunixin meglumine/kg of body weight, po/day for 30 days in an encapsulated form that was divided into 2 doses/day (group 1; n = 3) or by im injection once a day (group 2; n = 7). Three control foals (group 3; n = 3) were administered capsules (n = 1) containing dextrose powder or im injections (n = 2) of vehicle solution without flunixin meglumine. All 3 group-1 foals given flunixin meglumine po developed oral ulcers. Group-2 foals given flunixin meglumine im did not develop oral ulcers. One control foal (group 3) developed 1 oral ulcer that healed during the study. Endoscopic examination revealed linear crease-like mucosal lesions in the glandular portion of the stomach in 2 group-2 foals. Radiographic evidence of gastric ulcers was observed in only 1 gastrogram of a group-1 foal.

Foals were euthanatized, and necropsy revealed erosions and/or ulcers of the glandular portion of the stomach. Oral ulcers were observed in all 3 group-1 foals. Erosions of the glandular portion of the stomach developed in all 10 foals given flunixin meglumine, but did not develop in group-3 foals. Ulceration of the glandular portion of the stomach was present in 1 group-2 foal.
Uterine motility during the estrous cycle: Studies in healthy bitches
Authors: Wheaton Lynn G. , Pijanowski Gerald J. , Weston Patricia G. , Burke Thomas J.
Published: February 2025

Natural and drug-induced uterine motilities (um) were recorded via uterine-implanted catheter-tip pressure transducers in 5 bitches during proestrus and estrus and in 6 bitches during early (30 days) and late (60 days) diestrus. The um was monitored in unanesthetized bitches for 2 days after the estrous-cycle stage had been determined by vaginal cytologic findings. Natural um, expressed as Alexandria units (pressure × frequency × duration of contractions), was greatest during estrus, moderate during proestrus, and appreciably decreased or lacking during early and late diestrus. During proestrus and estrus, prostaglandin F2α (5 μg/kg of body weight, iv) induced intrauterine pressures of 107 and 115 mm of Hg, respectively, and oxytocin (0.05 USP units/kg, iv) induced pressures of 106 and 116 mm of Hg, respectively. In contrast, the intrauterine pressure values induced by prostaglandin F2α given iv during early and late diestrus were 61 and 58 mm of Hg, respectively, and for oxytocin, were 61 and 51 mm of Hg, respectively. Prostaglandin F2α given im (50 μg/kg) also induced a greater intrauterine pressure during proestrus and estrus than during diestrus. We concluded that in the bitch, natural and drug-induced um are decreased during early and late diestrus.
Circulating immune complex concentrations in selected cases of skin disease in dogs
Authors: DeBoer Douglas J. , Ihrke Peter J. , Stannard Anthony A.
Published: February 2025

Serum samples from 25 clinically normal dogs and 137 base-line serum samples from dogs with skin disease were assayed blindly for presence of circulating immune complexes (cic). The method used was a solid-phase C1q-binding enzyme-linked immunosorbent assay. This assay detected only IgG-containing cic that were capable of binding C1q. Statistical analysis revealed that dogs with systemic lupus erythematosus, discoid lupus erythematosus, generalized demodicosis, and recurrent staphylococcal pyoderma had significantly higher mean cic concentrations than did normal dogs. Dogs with other skin diseases had mean cic concentrations indistinguishable from those of normal dogs. Presence of cic in dogs with these dermatopathies may have pathogenetic significance or may be the result of the disease process. Further studies are necessary to define the antigens contained in the immune complexes and the importance of cic in skin disease of dogs.
Anal sphincter pressure and the rectosphincteric reflex in the dog
Authors: Strombeck Donald R. , Harrold Doris
Published: February 2025

Anal sphincter pressure (asp) was measured in healthy conscious dogs, and the rectosphincteric reflex that causes inhibition of the internal sphincter was identified. Pressures were measured in 6 dogs by use of a perfused miniature 4-lumen catheter. To identify the rectosphincteric reflex, a balloon (fitted over the distal opening of the catheter) was insufflated with 25 ml of air.

Mean (± se) asp was 74.7 ± 4.2 mm of Hg. When the rectosphincteric reflex was stimulated by balloon distension, asp decreased to 35.9 ± 4.9 mm of Hg. The reduction in pressure persisted for 22 ± 1.5 s, and asp returned to predistension values, despite the maintenance of balloon distension. Atropine did not affect asp or its reduction during balloon distension.
Predictive value of tracer studies for 131I treatment in hyperthyroid cats
Authors: Broome Michael R. , Turrel Jane M. , Hays Marguerite T.
Published: February 2025

In 76 cats with hyperthyroidism, peak thyroidal radioiodine (131I) uptakes and effective half-lives were determined after administration of tracer and therapeutic activities of 131I. In 6 additional hyperthyroid cats, only peak thyroidal uptakes after administration of tracer and therapeutic activities of 131I were determined. Good correlation was found between peak thyroidal uptakes of tracer and therapeutic 131I; however, only fair correlation was observed between effective half-lives. In 79% of the cats, the effective half-life for therapeutic 131I was longer than that for tracer 131I. After administration of therapeutic activity of 131I, monoexponential and biphasic decay curves were observed in 51 and 16 cats, respectively.

Using therapeutic kinetic data, radiation doses to the thyroid gland were calculated retrospectively on the basis of 2 methods for determining the activity of 131I administered: (1) actual administration of tracer-compensated activity and (2) hypothetic administration of uniform activity (3 mCi). Because of the good predictive ability of tracer kinetic data for the therapeutic kinetic data, the tracer-compensated radiation doses came significantly (P = 0.008) closer to the therapeutic goal than did the uniform-activity doses. In addition, the use of tracer kinetic information reduced the extent of the tendency for consistently high uniform-activity doses.

A manual method for acquiring tracer kinetic data was developed and was an acceptable alternative to computerized techniques. Adoption of this method gives individuals and institutions with limited finances the opportunity to characterize the iodine kinetics in cats before proceeding with administration of therapeutic activities of 131I.
Effects of source and washing of erythrocytes on growth of bacterial pathogens from the bovine mammary gland
Authors: Shearer J. K. , Brown M. B. , Reed P. A.
Published: February 2025

Effects of source and washing of rbc on quantitative growth and hemolytic zone sizes of common bacterial pathogens of the bovine mammary gland were evaluated. Blood samples used to prepare the blood agar media were obtained from 10 adult dairy cows, 10 dairy calves, and 10 sheep. Hemolytic zone sizes produced by Staphylococcus aureus were significantly (P < 0.01) larger on blood agar prepared with washed rbc than on blood agar prepared with nonwashed rbc, regardless of rbc source. With the exception of Corynebacterium bovis, growth of all bacteria was equivalent or significantly higher on medium prepared with washed rbc, compared with that on medium prepared with nonwashed rbc, regardless of rbc source. Significantly higher numbers of C bovis (P < 0.01) and Streptococcus agalactiae (P < 0.01) were isolated on medium prepared with washed cow rbc. Significantly higher numbers of Str uberis (P < 0.01) and S aureus (P < 0.05) were isolated on medium prepared with washed sheep rbc and washed calf rbc, respectively. Growth of Escherichia coli was not affected by the rbc source. Seemingly, rbc used in the preparation of medium should be washed. The source of rbc, as well as inter-animal variation, also should be considered in the quality control of medium.
Serodiagnosis of Histophilus ovis-associated epididymitis in rams
Authors: Walker Richard L. , LeaMaster Brad R. , Biberstein Ernst L. , Stellflug John N.
Published: February 2025

An elisa for the detection of antibodies to Histophilus ovis was used to evaluate the association of epididymal lesions in rams with serologic response to His ovis. Comparison of elisa results for His ovis in groups of rams with epididymal lesions with elisa results of clinically normal rams (control group) revealed a significant difference (P < 0.01) between the control group and those rams from which His ovis was isolated. A significant difference (P < 0.01) was noticed between the control group and rams with lesions from which an organism other than His ovis or Brucella ovis was isolated. Additionally, a significant difference (P < 0.01) was noticed in elisa results between the control group and affected rams from which no organism was recovered and in which the epididymal lesion was not limited to the head of the epididymis. A difference was not detected in the His ovis elisa results between control rams and rams with lesions associated with a B ovis infection or rams from which no organism was recovered and in which the epididymal lesion was limited to the head of the epididymis.

The serologic findings in our study suggest that His ovis is more important in the development of epididymitis in rams than culture results alone would indicate.
Characterization of fibroblast colony-forming units in bone marrow from healthy cats
Authors: Wellman Maxey L. , Kociba Gary J.
Published: February 2025

The adherent cell layer of bone marrow from healthy cats was characterized in vitro, and the mean fibroblast colony-forming unit (cfu-f) was determined. The majority (82%) of the cells in the adherent cell layer were spindle-shaped fibroblastic cells. These cells were weakly positive for acid phosphatase activity and negative for α-naphthyl butyrate esterase and alkaline phosphatase activities. They did not phagocytose latex beads. The remaining cells (18%) in the adherent cell layer resembled macrophages. They were strongly positive for acid phosphatase and α-naphthyl butyrate esterase activities, and they phagocytosed latex beads.

The mean cfu-f per 106 mononuclear cells in bone marrow from healthy kittens and adult cats was 62 and 65, respectively. The cfu-f assay was linear over a range of 0.25 to 1.25 × 106 bone marrow mononuclear cells cultured. Variation in the feline cfu-f assay was similar to that reported for the human cfu-f assay. Bone marrow collections repeated at 1-month intervals (from the same bone) did not affect cfu-f concentration. A difference was not observed between cfu-f cultured from the feline humerus or femur.

Bone marrow adherent cells in cats resembled those described for other species. Results of the feline cfu-f assay were consistent and repeatable and were similar to those reported for other species.
Rhodococcus (Corynebacterium) equi: Bactericidal capacity of neutrophils from neonatal and adult horses
Authors: Martens Judy G. , Martens Ronald J. , Renshaw Harland W.
Published: February 2025

The capacity of hematogenous polymorphonuclear neutrophilic leukocytes (pmnl) to kill Rhodococcus equi was compared in horses of various ages. A radioisotope bactericidal assay was used to determine the capacity of pmnl to kill R equi. Assays were conducted on pmnl from horses in 3 groups: group I, 13 foals with a mean age of 3.3 days; group II, 10 group-I foals at a mean age of 35.7 days; and group III, adult dams of group-I foals. Bacteria were obtained from the lungs of a foal with R equi pneumonia and opsonized with fresh adult equine serum that contained R equi specific antibody.

The mean peak percentage of R equi killed by pmnl was 78.9 for group I, 90.1 for group II, and 87.9 for group III. There was no significant difference (P > 0.05) among groups; however, 15% of foals in group I (2 foals) had a mean peak percentage of 30.5 killed, which was significantly (P < 0.05) lower than the percentage for other foals in group I. The results of our investigation indicated that the capacity of pmnl to kill opsonized R equi is similar in neonatal, young, and adult horses. However, some neonatal foals have a substantially lower capacity to kill R equi, which may be an important factor in the pathogenesis of R equi infections.
Comparative albumin determinations in ducks, chickens, and turkeys by electrophoretic and dye-binding methods
Authors: Spano J. S. , Whitesides J. F. , Pedersoli W. M. , Krista L. M. , Ravis W. M.
Published: February 2025

Serum total protein, albumin, and globulin concentrations in male ducks, turkeys, and chickens were compared, using electrophoretic and dye-binding methods, as well as using a bovine and chicken albumin standard. When a chicken standard was used for determination of albumin and globulin concentrations by automated methods, results were more comparable with results of electrophoresis than were those when a bovine standard was used.
Light and electron microscopic changes in corneas of healthy and immunomodulated calves infected with Moraxella bovis
Authors: Kagonyera George M. , George Lisle W. , Munn Robert
Published: February 2025

Thirty-nine Holstein calves (50 to 100 kg and 2 to 3 months old) were randomly assigned to 4 groups. Calves in group I (n = 12) were inoculated with Moraxella bovis and were euthanatized 24 hours (6 calves) or 8 days after inoculation (6 calves). Group-II calves (n = 12) were treated with hydroxyurea for 6 days, and then 6 of these calves were inoculated with M bovis. The daily hydroxyurea treatments continued for 14 days, and then all calves in group II were euthanatized. Group-III calves (n = 9) were administered dexamethasone parenterally, beginning 24 hours before inoculation with M bovis, and then daily thereafter, until they were euthanatized at either 24 hours (n = 5) or 8 days (n = 4). Group-IV calves (n = 6) were inoculated with M bovis, and euthanatized 12 hours later. Tears were collected from all calves that had been inoculated more than 24 hours earlier. The concentration of myeloperoxidase and collagenase was determined for each sample. After the calves were euthanatized, the corneas were dissected free, fixed, and examined by use of scanning or transmission electron microscopy, or light microscopy.

Microscopic corneal erosions were detected 12 hours after inoculation. These lesions were not accompanied by inflammatory cell infiltration and were detected by use of scanning electron microscopy. Inflammatory cells were first observed in the corneal lesions in specimens collected 24 hours after inoculation. Bacteria that resembled M bovis morphologically were seen in several locations in these lesions. By 8 days, corneas of the group-I calves had the least number of intracorneal bacteria, compared with the corneas from other groups. The number of calves that developed corneal ulcers by 8 days was similar in all groups. The corneal ulcers of the hydroxyurea-treated calves were shallower, but appeared larger in surface area than those of the controls. By 8 days after inoculation, the corneal ulcers of the dexamethasone-treated calves had less corneal neovascularization and opacification than did the controls. Corneal perforations developed in 2 eyes of the dexamethasone-treated calves, but did not develop in any eyes of the controls. Microscopically, a larger number of M bovis were observed in corneas of dexamethasone-treated calves than in corneas of calves from other groups.

Collagenase was not detected in any tear samples. The concentration of myeloperoxidase in tear samples were significantly (P < 0.05) higher in the prehydroxyurea-treatment samples than in the posttreatment samples from corresponding calves.
Pathophysiologic mechanism of cardiac dysfunction in experimentally induced heartworm caval syndrome in dogs: An echocardiographic study
Authors: Atkins Clarke E. , Keene Bruce W. , McGuirk Sheila M.
Published: February 2025

In dogs with experimentally induced heartworm infection, the onset of caval syndrome (cs) was characterized by a murmur, loudest over the tricuspid valve, and a large worm mass in the right ventricular lumen detectable during diastole by use of M-mode echocardiography. Two-dimensional echocardiography indicated that the worm mass was located in the right atrium and venae cavae and was “flowing” into the right ventricle during rapid diastolic filling. Paradoxical septal motion and vigorous right ventricular cranial wall motion also were observed. Other echocardiographic changes included decreased size of the left atrium and ventricle, aortic root, and ratio of left-to-right ventricular diastolic luminal diameter, compared with values obtained 6 months after experimentally induced heartworm infection. Right ventricular end diastolic diameter increased considerably. Most echocardiographic indices of left ventricular function (fractional shortening, velocity of circumferential fiber shortening, ejection fraction, and preejection period) were not altered appreciably, but estimates of cardiac index and stroke volume were markedly decreased.

Electrocardiography revealed ventricular and supraventricular premature complexes in 7 of the 8 dogs studied, evidence of right ventricular enlargement in 6 of the 8 dogs studied, and increased mean heart rate, compared with that measured 6 months after inoculation of infective larvae, before the onset of cs.

Cardiac catheterization was performed in 3 dogs at the onset of cs. Severe pulmonary arterial and right ventricular hypertension and decreased cardiac index (compared with values obtained before inoculation) were observed. Evidence of right ventricular inflow obstruction was not detected. Mean aortic blood pressure decreased with the onset of cs, but right ventricular end diastolic pressure increased.

On the basis of these findings, a pathophysiologic mechanism for heart failure associated with heartworm cs was proposed. It involved the combination of newly acquired tricuspid valvular insufficiency and preexistent pulmonary hypertension leading to right-sided heart failure. Subsequent unloading of the left ventricle was likely responsible for diminished cardiac output in the face of apparently normal left ventricular function.
Effect of β-tricalcium phosphate in surgically subchondral bone defects in male horses
Authors: Rose P. L. , Auer J. A. , Hulse D. , Hightower D. , Schenk R. K.
Published: February 2025

β-Tricalcium phosphate (tcp) was evaluated as a synthetic bone grafting material in horses. Sixteen horses were randomly assigned to 4 groups of 4 horses. In each horse, an 11-mm by 10-mm circular defect with a smooth margin was created surgically in the weight-bearing surface of both third metacarpal bones (McIII) and the left third metatarsal bone. The defect in the left McIII was filled with tcp, the defect in the right McIII was filled with a mixture of 50% autogenous cancellous bone (acb) and 50% tcp, and the defect in the left third metatarsal bone was not filled to serve as a control.

Nuclear imaging and radiographic evaluation of surgical sites were performed at postsurgical week (psw) 4 and 13 in group-I horses and at psw 26, 39, and 52 in groups-II, -III, and -IV horses, respectively. Horses in groups I, II, III, and IV were euthanatized at psw 13, 26, 39, and 52, respectively, and specimens were harvested for histologic evaluation. Results were compared among treatment methods, as well as among time intervals.

The greatest activity at defect sites was seen in group-I horses at psw 4. Activity counts in limbs of group-I horses at psw 13 and counts in limbs of group-II horses at psw 26 were not significantly (P ≤ 0.05) different. Activity counts in groups-III and -IV horses at psw 39 and 52, respectively, were less than those in groups I and II. However, there was no significant difference in activity counts between limbs implanted with tcp or acb:tcp.

The radiographic appearance of defects in treated limbs and in control limbs was similar within each group. Defects increased in radiodensity and were poorly visualized, if at all, in group-IV horses at psw 52. Osseous changes compatible with degenerative joint disease were present in 10 of 32 (31%) tcp- and acb:tcp-implanted limbs.

Morphometric evaluation was performed to evaluate the percentage of bone and tcp in the deepest third of the initial defect. When results were compared among treatment methods, control defects contained a greater percentage of bone than did tcp- or acb:tcp-implanted defects in groups I, II, and IV, respectively, at psw 13, 26, and 52. At no time did the tcp- and acb:tcp-implanted defects have differences in the percentage of bone. However, evaluation of results among time intervals revealed significant differences (P ≤ 0.05) in all variables. In general, the percentage of bone increased and the percentage of tcp decreased in defects of each sequential group of horses.

Both tcp and acb:tcp were gradually resorbed and replaced by bone. Therefore, tcp was effective as a synthetic bone-grafting material in the horse. However, no advantage was gained by the use of tcp, because controls healed as well as did defects implanted with tcp or acb:tcp. β-Tricalcium phosphate use cannot be advocated in bone defects occurring adjacent to the joint surface of the horse.
Inheritance of diabetes mellitus in Keeshond dogs
Authors: Kramer John W. , Klaassen James K. , Baskin Denis G. , Prieur David J. , Rantanen Norman W. , Robinette Jack D. , Graber Wanda R. , Rashti Linda
Published: February 2025

The genetic aspects of inherited, insulin-dependent diabetes mellitus of Keeshond dogs were studied retrospectively and in a prospective mating program. The symbol dm was used to designate the gene that causes hypoplasia of the islets of Langerhans. The retrospective study disclosed 4 diabetic dogs; prospective outcross, backcross, and inbred matings disclosed 49 diabetic dogs.

Outcrossing demonstrated that the diabetic phenotype was displayed readily against a genetic background of a breed other than the Keeshond. In dogs with the dm/dm genotype, onset of diabetes was most frequent before the dog was 6 months old, but did occur in some older dogs. The dm genotype was best described as autosomal recessive.
Cardiovascular effects of hydralazine HCl administration in horses
Authors: Bertone Joseph J.
Published: February 2025

Six standing awake adult horses were instrumented for measurement of mean arterial, central venous, and pulmonary arterial blood pressures (mm of Hg), thermodilution cardiac output (ml/kg/min), and pulmonary arterial blood temperature (C). Total peripheral resistance was calculated from these values. Base-line data were accumulated, and a single dose of hydralazine HCl (0.5 mg/kg) was administered iv. Horses were monitored for 420 minutes after hydralazine administration. Mean arterial and central venous blood pressures did not change from the base-line values. Cardiac output and heart rate were increased above base-line values for 260 minutes. Total peripheral resistance was decreased for 240 minutes. Pulmonary arterial blood temperature was decreased for 60 minutes after drug administration. Mean pulmonary arterial pressure relative to the base-line mean was intermittently decreased during the study. Intravenously administered hydralazine HCl appears to be an effective vasodilator, with moderate duration of action in horses.