bluuebunny/crossref_metadata_2025 huggingface dataset:
Radioimmunoassay for Anaplasma marginale antibodies in cattle
Authors: Schuntner C. A. , Leatch G.
Published: February 2025

A radioimmunoassay is described for use in the detection of Anaplasma marginale antibodies in cattle sera. Optimal sensitivity and specificity were obtained by using 2 antigens, an A marginale antigen and a rbc antigen (obtained before infection was established) from the same calf. In addition, sera were preabsorbed with rbc from healthy cattle and with sonicated Babesia bovis. Of 86 sera obtained from cattle with A marginale infection (as determined by blood smear examination or by results of subinoculation of blood from such infected cattle into splenectomized calves), 85 had positive results by use of this test. Of 100 sera obtained from cattle raised in an anaplasmosis-free area, 98 yielded negative results, and sera obtained from 35 cattle (97 sera) infected with B bigemina and from 18 cattle infected with Theileria orientalis yielded negative results. By use of this test, 99 of 100 sera obtained from cattle with B bovis infection were negative for A marginale. Anaplasma marginale antibodies were detected in 18 cattle that had been pastured in a Boophilus microplus-free area for 2 years after natural infection. After 3 years, 16 of these cattle were still seropositive for A marginale. Sixteen cattle pastured in a Bo microplus-infested area had detectable antibody against A marginale 27 months after initial infection with A marginale. Sensitivity and specificity of the test were assessed as 98.8% for each.
Epidermal cell renewal in the horse
Authors: Baker Benjaman B. , Stannard Anthony A. , Maibach Howard I.
Published: February 2025

Epidermal cell labeling index and cell renewal time were estimated in 8 adult horses, using autoradiography after [3H]thymidine was given intradermally. The mean labeling index was 1.45 ± 0.47%, and the mean cell renewal time of the viable epidermis was approximately 17 days.
Neurophysiologic maps of the cutaneous innervation of the external genitalia of the ewe
Authors: Kirk E. J. , Kitchell R. L.
Published: February 2025

The area of skin supplied by the afferent fibers in a peripheral nerve is called the cutaneous area (ca) of that nerve. The ca responsive to movement of wool or hair in the genital regions were mapped in 17 ewes, with the identifications of the peripheral nerves and of the spinal nerves contributing to the pudendal plexus being checked at necropsy.

Differences were found in the origins and extent of ca of the cutaneous branches from the sacral plexus. The ca of the caudal rectal nerves and of a nerve that passed caudally between the caudal vertebrae and the ventral sacrococcygeus muscle lay lateral to the anus and in the adjacent skin of the tail. The ca of the proximal cutaneous branch and of the distal cutaneous branch from the pudendal nerve (or plexus) overlapped craniocaudally (by approx one-half) the ca of the distal cutaneous branch extending ventrally and ending just caudal to the ipsilateral mammary gland. The deep perineal nerve innervated the skin immediately lateral to the anus and vulva.

The dorsal nerve of the clitoris innervated hairs on the ipsilateral half of the vulva. Other fibers in the pudendal nerve were presumed to pass into the mammary branch of the nerve. They innervated the skin ventral to the vulva, the ipsilateral mammary gland, and (in some ewes) areas of the skin cranial to the mammary gland.

The ca of the genitofemoral nerve included the ipsilateral teat and the inguinal fossa. The ventral cutaneous branches of the caudal thoracic spinal nerves and of the first 2 or 3 lumbar spinal nerves reached the ventral midline caudal to the umbilicus and overlapped with cranial extensions of the pudendal ca.
Establishment of equine T-lymphocyte cultures dependent on recombinant human interleukin-2
Authors: Stott Marcia L. , Osburn Bennie I.
Published: February 2025

Long-term equine lymphocyte cultures were initiated and maintained in continuous culture with medium containing recombinant human interleukin-2. Cultures were successfully maintained with lectin activation signals and recombinant human interleukin-2 or with recombinant human interleukin-2 alone. All cell cultures that were characterized had a T-lymphocyte phenotype and had lectin-dependent or -independent cytotoxicity directed to various cell types. Those findings demonstrate that longterm equine T-lymphocytes cultures can be initiated and maintained easily.
Pathogenesis of porcine enteric calicivirus-like virus in four-day-old gnotobiotic pigs
Authors: Flynn William T. , Saif Linda J. , Moorhead Philip D.
Published: February 2025

Eighteen 4-day-old gnotobiotic pigs were orally inoculated with porcine enteric calicivirus-like virus (C strain). Seven additional gnotobiotic pigs served as noninoculated controls. Mild diarrhea developed in all inoculated pigs by postinoculation day (pid) 3 and persisted for 3 to 7 days. Severe diarrhea developed in 2 inoculated pigs between pid 4 and 5. Twelve inoculated and 7 control pigs were euthanatized over a 7-day period. Small intestinal mucosal smears were stained with a fluorescein-conjugated anti-porcine enteric calicivirus-like virus serum. Immunofluorescence was observed in villous epithelial cells (primarily in the duodenum or jejunum) of all inoculated pigs, except for 1 pig euthanatized at pid 7. Villus length was determined in histologic sections of the small intestinal specimens from control and inoculated pigs. Statistically significant (P < 0.01) villus atrophy was found in the duodenum and/or jejunum of inoculated pigs at pid 3 to 7. These observations were confirmed by scanning electron microscopy, which revealed shortening, blunting, fusion, or absence of villi in the duodenum and jejunum of inoculated pigs at pid 3 to 7. Lesions were not seen in control pigs. Calicivirus-like particles were detected by immune electron microscopy in the large intestinal contents and feces of inoculated pigs from pid 1 to 7.
Purification and characterization of the 1q subcomponent of canine complement and its use in the 125I-C1q binding assay for detection of immune complexes
Authors: Wu Ching-Ching , Bey Russell F. , Loken Keith I.
Published: February 2025

The complement subcomponent, C1q, was isolated from serum obtained from clinically normal dogs, using a rapid 2-step process involving affinity chromatography. Yield of C1q ranged from 8 to 10 mg/L of serum. Hemolytically active C1q had 3 protein bands after sodium dodecyl sulfate polyacrylamide gel electrophoresis under reducing conditions and formed a single line of identity with rabbit anti-canine C1q. The amino acid composition of canine C1q was similar to that of human C1q and contained a high percentage of glycine. Isolated canine C1q was iodinated, and the fluid-phase binding assay was used to detect circulating immune complexes in dogs with systemic lupus erythematosus and rheumatoid arthritis.
Efficacy of acaricides against chorioptic mange of goats
Authors: Wright Fred C. , Guillot Frank S. , George John E.
Published: February 2025

Angora goats heavily infested with Chorioptes bovis were dipped one time in either 0.05% amitraz, 0.27% coumaphos, 0.05% fenvalerate, or 0.03% lindane. Control of the mites by the single dips was evaluated for 21 days. Amitraz caused 98% mortality of the mites initially. Both coumaphos and lindane caused > 85% mortality at 3 days, but mite numbers increased rapidly thereafter. Only fenvalerate killed all of the mites.
Minimum anesthetic dose and cardiopulmonary dose response for halothane in chickens
Authors: Ludders John W. , Mitchell Gordon S. , Schaefer Susan L.
Published: February 2025

The minimum anesthetic dose (mad) and the cardiopulmonary dose-response for halothane were determined in male chickens. The mad for halothane was 0.85 ± 0.09% (mean ± sd), with a range of 0.75% to 0.98%. There was a significant (P < 0.002) positive correlation between increasing concentrations of halothane and Paco2, and significant negative correlations of halothane concentration with respiratory rate (P < 0.04), arterial blood pH (P < 0.008), and mean arterial blood pressure P < 0.008). A significant correlation was not found between halothane concentration and heart rate or arterial blood bicarbonate concentration. It was concluded that the mad for halothane in chickens is similar to values for minimum alveolar concentrations of halothane in mammalian species, and that there is substantial dose-dependent depression of cardiopulmonary function in chickens.
Cytopathic effects of Moraxella bovis on cultured bovine neutrophils and corneal epithelial cells
Authors: Kagonyera George M. , George Lisle W. , Munn Robert
Published: February 2025

The effects of Moraxella bovis on the morphologic features of purified bovine neutrophils and bovine corneal epithelial cells were examined, using transmission and scanning electron microscopy and light microscopy. Within 2 minutes after incubation of bovine neutrophils with living M bovis, electron microscopic cellular changes included vacuolation, swelling, and loss of microplicae. Most of the neutrophils were lysed by 10 minutes of incubation. Human neutrophils phagocytosed the M bovis and remained intact, even after 30 minutes of incubation with the bacteria. Living M bovis killed bovine corneal epithelial cells in vitro. Sterile filtrates prepared from 6-hour shaker cultures of M bovis also killed bovine corneal epithelial cells, but the cytotoxic activity was less than that produced by the living bacteria. Cellular changes were first observed in specimens collected 1 hour after corneal cell monolayers were inoculated with sterile culture filtrates. The changes in these cells included pit-like lesions on the cellular surface, cellular separation, and vacuolation.
Relationship among transmissible gastroenteritis virus antibody titers in serum, colostrum, and milk from vaccinated sows, and protection in their suckling pigs
Authors: Moxley Rodney A. , Olson LeRoy D. , Solorzano Robert F.
Published: February 2025

We studied the antibody responses to transmissible gastroenteritis (TGE) in serum, colostrum, and milk from sows vaccinated with 2 attenuated (1 IM and 1 oral-IM) and 1 nonattenuated live vaccines and the relationship of these responses with the survivability of the sow's suckling pigs after challenge exposure with virulent TGE virus. Contrary to previous studies, the anti - TGE virusneutralizing geometric mean titers (GMT) in the milk of sows vaccinated with attenuated vaccines at 3 and 5 days of lactation were similar to that found in the colostrum. Colostral and serum antibody titers were highest in sows given 2 injections of the IM attenuated vaccine. Half of the sows given the oral - IM attenuated vaccine did not seroconvert after 2 oral doses. Only sows vaccinated with the nonattenuated live vaccine had milk GMT that remained high for 21 days after farrowing. The linear relationship between colostral GMT and percentage of survivability of suckling pigs challenge exposed at 3 days of age was significant (P < 0.05), although the relationship between serum GMT and percentage of survivability and the relationship between milk GMT and percentage of survivability were not significant (P> 0.10). The linear relationship between colostral (P < 0.10) or pre-challenge exposure milk (P < 0.05) GMT and percentage of survivability of suckling pigs challenge exposed at 5 days of age was significant. We have no adequate explanation for the relatively low colostral GMT, the relatively high milk GMT at 3 and 5 days of lactation in vaccinated sows, or the lack of significant linear relationship between milk GMT and survivability of pigs challenge exposed at 3 days of age.
Porcine malignant hyperthermia susceptibility: Halothaneinduced increase in cytoplasmic free calcium in lymphocytes
Authors: O'Brien Peter J. , Kalow Barbara I. , Brown Brian D. , Lumsden John H. , Jacobs Robert M.
Published: February 2025

We tested the hypothesis that lymphocytes from swine with susceptibility to malignant hyperthermia (MH) had increased sensitivity to the membrane-perturbing effects of halothane that increase cytoplasmic calcium. Cytoplasmic concentration of ionized calcium in lymphocytes isolated from blood was determined in the presence and absence of halothane for 10 Pietrain × Poland China swine that were susceptible to MH and 20 Yorkshire swine that were resistant to MH. Calcium was determined by dualemission spectrofluorometry and by measuring the ratio of free to calcium-bound form of the fluorescent calcium dye Indo-1. Mean values for calcium concentrations in lymphocytes from MH-susceptible (MHS) swine were 80% less than control values (40.5 ± 38.8 and 185.3 ± 91.6 nmol/L; P < 0.01). Untreated lymphocytes from MHS swine accumulated calcium at half the rate observed for controls. Exposure to 1 mmol/L halothane resulted in a 3-fold increase of free calcium concentration to 127.9 ± 81.3 nmol/L in the lymphocytes of MHS swine, but had no significant effect on lymphocytes from control swine (225.0 ± 91.4; P < 0.01). Exposure to 2 mmol/L halothane resulted in a 6 - fold increase of free calcium concentration to 255.9 ± 91.4 nmol/L in lymphocytes from MHS swine and a 63% increase in lymphocytes from controls (303.8 ± 116). The rate of halothane-induced increase in cytosolic calcium was 13 times greater in lymphocytes from MHS swine, compared with controls. These data indicated that the molecular defect that results in halothane-hypersensitivity and is characteristic of muscle of MHS swine also occurs in lymphocytes from MHS swine.
Effect of xylazine in heifers under thermoneutral or heat stress conditions
Authors: Fayed A. H. , Abdalla E. B. , Anderson R. R. , Spencer K. , Johnson H. D.
Published: February 2025

A study was performed to assess the effect of xylazine HCl (0.1 mg/kg of body weight, IV) in heifers maintained at thermoneutrality (18 C, 42% humidity) or under heat stress (33 C, 63% humidity) conditions. Xylazine caused 50 and 70% decreases in serum insulin concentrations in the thermoneutral and heat-stressed heifers, respectively. Xylazine-induced hypoinsulinemia was associated with hyperglycemia. In the thermoneutral group, serum glucose concentrations increased from a basal concentration of 75 mg/dl to 150 mg/dl after 15 minutes. In the heat stress group, the serum glucose concentration increased from 65 mg/dl to 105 mg/dl. Hyperglycemia peaked at 2 hours and remained high for 6 hours after xylazine administration. Heat-stressed heifers took a longer time (107 minutes) to stand than did heifers under thermoneutral conditions (41 minutes). The time to regain sensation to pain was significantly prolonged in heat-stressed heifers. Xylazine had no effect on body temperature and respiration rate in heifers under the thermoneutral condition, whereas it markedly induced hyperthermia and suppressed respiration rate in the heat-stressed heifers. Furthermore, the pulse rate was slightly decreased in thermoneutral heifers and was markedly decreased in the heat-stressed heifers.
Onchocerca gutturosa and Onchocerca lienalis in cattle: Variation in length of microfilariae by site of recovery
Authors: Harty T. M. , Ferenc S. A. , Copeman D. B. , Courtney C. H.
Published: February 2025

Dermal microfilariae recovered from specimens obtained from umbilical and cervical sites of cattle infected with adult Onchocerca gutturosa alone or with adults of O gutturosa and O lienalis were measured and compared with uterine microfilariae obtained directly from gravid female worms of each species.

Uterine microfilariae of O gutturosa were longer than dermal microfilariae obtained from cattle harboring only adults of O gutturosa. Dermal microfilariae were recovered from umbilical and cervical sites in these cattle. Those found at the cervical site had lengths equal to or greater than lengths of microfilariae recovered from the umbilical site. There was a significant (P < 0.0001) shift in length across populations of microfilariae of O gutturosa from various sites in its bovine host, with a progressive decrease in length between microfilariae recovered from the worm's uterus, microfilariae from the cervical dermis, and microfilariae from the umbilical dermis, respectively. A similar direct comparison was not possible for microfilariae of O lienalis, because none of the cattle was infected with only adult worms of this species. In an indirect comparison, microfilariae of O lienalis were identified at the umbilicus, but their presence in the cervical region could not be determined unequivocally because of confounding of microfilariae length by concurrent infection with O gutturosa. Uterine microfilariae from O lienalis were longer than uterine microfilariae of O gutturosa, although a degree of overlap in the range of measurements existed between species.
Serum relaxin and progesterone concentrations in pregnant, pseudopregnant, and ovariectomized, progestin-treated pregnant bitches: Detection of relaxin as a marker of pregnancy
Authors: Steinetz Bernard G. , Goldsmith Laura T. , Harvey H. Jay , Lust George
Published: February 2025

Serum concentrations of relaxin and progesterone were measured by specific radioimmunoassays in pregnant, pseudopregnant, or ovariectomized (between gestation weeks 4 and 5) pregnant Labrador Retriever bitches. Daily administration of 17α -ethyl - 19 - nortestosterone was performed to maintain gestation in the ovariectomized pregnant bitches. This synthetic gestagen was selected because it did not interfere with the assay for endogenously secreted progesterone concentration in serum.

Serum progesterone concentration was high in ovarianintact pregnant or pseudopregnant bitches, but the mean progesterone concentration in pseudopregnant bitches (evaluated at 4 weeks after mating) was only 56% of the concentration in pregnant bitches. After ovariectomy, serum progesterone concentration decreased to undetectable values. Unlike progesterone, serum relaxin concentration increased during the latter half of pregnancy in the ovarian-intact and in the ovariectomized pregnant bitches, but relaxin was not detectable at any time in the pseudopregnant bitches.

The amount of relaxin pregnant measured in the ovariectomized pregnant bitches was less (P < 0.05) than that in overianintact bitches, suggesting that the ovaries may have contributed to the total circulating relaxin concentration in the latter. Placental production of relaxin might have accounted for the serum relaxin concentration after ovariectomy; thus, the ovary and placenta each may secrete relaxin during gestation in bitches.

Regardless of its source, measurement of serum relaxin concentration may offer a useful way of distinction between pregnancy and pseudopregnancy in dogs.
Increased peroxidation of erythrocytes of stress-susceptible pigs: An improved diagnostic test for porcine stress syndrome
Authors: Duthie Garry G. , Arthur John R. , Bremner Patricia , Kikuchi Yuji , Nicol Fergus
Published: February 2025

When incubated with solutions of hydrogen peroxide, erythrocytes of stress-susceptible pigs produced more by-products of lipid peroxidation (as measured as thiobarbituric acid-reactive substances [tbars]) than did erythrocytes from stress-resistant pigs. Using this technique, discrimination between the 2 pig types was absolute at hydrogen peroxide concentrations of 0.9 and 1.5%. This was in contrast to other methods of identifying stress-susceptible pigs, such as osmotically induced erythrocyte lysis and the determination of plasma pyruvate kinase and creatine kinase activities, for which considerable overlap of data was observed between pig types. The increased tbars production by erythrocytes was further evidence for the existence of an antioxidant abnormality in stress-susceptible pigs. However, because there were no discernible differences in the major blood antioxidant-related values between stress-susceptible and stress-resistant pigs, the nature of the defect remains unclear. The production of tbars by erythrocytes when incubated with hydrogen peroxide provides an improved method for identifying stress-susceptible pigs.
Echocardiographic assessment of cardiac chamber size and functional performance in swine
Authors: Gwathmey Judith K. , Nakao Shoichiro , Come Patricia C. , Abelmann Walter H.
Published: February 2025

Ninety nonanesthetized 7- to 16-week-old pigs were studied, using 2-dimensional echocardiography that permits orientation of a targeted M-mode beam perpendicular to structures being studied and allows serial studies of the same cardiac regions. Normative data were obtained and included body weight and measurements of left atrial diameter, mitral valve excursion, aortic root diameter, left ventricular end-diastolic and end-systolic diameters, and left ventricular fractional shortening. A positive correlation was found between body weight and measurements of left atrial diameter, mitral valve excursion, aortic root diameter, left ventricular end-diastolic and end-syatolic diameters, and fractional shortening. A correlation was found between body weight and age. Best-fit analysis resulted in all measurements fitting either a first- or second-degree polynomial.
Detection of turkey enteric coronavirus by enzyme-linked immunosorbent assay and differentiation from other coronaviruses
Authors: Dea Serge , Tijssen Peter
Published: February 2025

A double-antibody ELISA for the detection of coronaviruses in intestinal contents from turkey poults with diarrhea was developed. Antibodies were raised in rabbits and guinea pigs against a Minnesota isolate of turkey enteric coronavirus (TCV) propagated in embryonating turkey eggs and were purified by density-gradient centrifugation. The specificity of antisera was confirmed by hemagglutination-inhibition and immunoelectron microscopy. Absorption of anti-TCV hyperimmune sera with egg extracts or egg ovalbumin and the use of different dilution and blocking buffers influenced the sensitivity and specificity of the ELISA. Reciprocal cross-reactivity was detected among turkey, chicken, bovine, and murine coronaviruses. Antisera to the transmissible gastroenteritis virus of swine, the rabbit enteric coronavirus, or the human coronavirus strain 299E failed to react with TCV. The TCV cross-reacted only moderately with the avian infectious bronchitis virus and the hemagglutinating en-cephalomyelitis virus of swine. Investigations with samples from 47 commercial turkey flocks in Quebec with episodes of transmissible enteritis revealed that the ELISA was more sensitive than was electron microscopy for detection of TCV.
Influence of dietary source of phosphorus on fecal and urinary excretion of phosphorus and other minerals by male cats
Authors: Finco Delmar R. , Barsanti Jeanne A. , Brown Scott A.
Published: February 2025

Twelve male cats were fed 2 diets that differed in the source of P. In diet 1 (14% P), 62.7% of P originated from poultry, meat, and fish meal, and the remainder from other organic ingredients of food. In diet 6 (1.6% P), 63.5% of P was derived from neutral monobasic/dibasic salts, and the remainder from other organic ingredients of the food.

The P intake was nearly the same with both diets, but there was a significant (P < 0.05) difference between diets in the percentage of ingested P that was excreted in the urine (14.7 ± 5.3% for diet 1; 34.9 ± 8.4% for diet 2), and in 6-day urinary P excretion (774 ± 290 mg for diet 1; 2,004 ± 556 mg for diet 2). The P concentrations in urine samples obtained by cystocentesis after cats ate were significantly (P < 0.05) higher when cats were fed diet 2 than when those same cats were fed diet 1. Plasma P concentrations increased after ingestion of diet 2, but were unchanged after ingestion of diet 1. Seemingly, urinary excretion of P was markedly influenced by dietary composition. Diets with the same P content have potential for different biologic effects because of differences m availability of P.
Effects of Pasteurella haemolytica leukotoxin on cultured bovine lymphoma cells
Authors: Clinkenbeard Kenneth D. , Mosier Derek A. , Timko Andrea L. , Confer Anthony W.
Published: February 2025

Leukotoxin activity from culture supernatants of Pasteurella, haemolytion serotype 1 in logarithmic growth phase caused rapid « 5 min) release of intracellular K+, uptake of extracellular Ca2+, and swelling of cultured bovine lymphoma cells (BL3 cells). Release of 51CrO42- and lactate dehydrogenase (LDH) from BL3 cells began after 15 minutes of incubation with leukotoxin at 37 C and was completed between 60 and 120 minutes of incubation. In addition, leukotoxin exposure of BL3 cells resulted in cell aggregation and adherence to glass surfaces. Scanning electron microscopy indicated that after 10 minutes of leukotoxin exposure, BL3 cells increased in size, and large membrane defects developed between 20 and 60 minutes of exposure. The rate of release of LDH from leukotoxin- exposed BL3 cells was proportional to the amount of leukotoxin added. At high cell concentrations, the activity of LDH released at completion was directly proportional to the amount of leukotoxin added. Leukotoxin-induced release of LDH required a divalent cation, whereas K+ release and cell swelling did not. The addition of Ca2+, Mn2+, and Ba2+ resulted in increased leukotoxin-induced release of LDH. Divalent cation concentrations of 0.5 to 2.5 mM resulted in 50% of maximal stimulation. Ethylene glycol-bis(ß-aminoethyl ether) N,N,N’,N’-tetraacetic acid blocked increased release of LDH caused by Ca2+ addition, but had no effect on K+ release or cell swelling. Leukotoxin action on BL 3 cells (K+ release, cell swelling, Ca2+ uptake, and release of LDH) was prevented by incubation at 4 C.
Cardiopulmonary changes in conscious dogs with induced progressive pneumothorax
Authors: Bennett R. Avery , Orton E. Christopher , Tucker Alan , Heiller Cynthia L.
Published: February 2025

Cardiopulmonary function was measured in 6 conscious dogs with progressive degrees of induced pneumothorax. Minute volume, respiratory rate, central venous pressure, systemic arterial pressure, pulmonary arterial pressure, pulmonaiy arterial occlusion pressure, heart rate, cardiac output, and arterial and mixed venous blood gases were determined before pneumothorax and at progressive volumes of pneumothorax equivalent to 50, 100, and 150% of the calculated lung volume. Tidal volume, pulmonary vascular resistance, alveolar to arterial O2 tension difference, physiologic dead space fraction, and pulmonary venous admixture also were calculated.

Linear increases in respiratory rate, central venous pressure, alveolar to arterial O2 tension difference, and pulmonary venous admixture differed significantly (P < 0.05). Linear decreases in tidal volume, pHv̄, pHa, Pv̄O2, and PaO2 were also significantly different. Quadratic increases were significantly different for pulmonary arterial pressure and pulmonary vascular resistance. Trends were not significantly different for other values.
Influence of major histocompatibility genes on serum hemolytic complement activity in miniature swine
Authors: Mallard B. A. , Wilkie B. N. , Kennedy B. W.
Published: February 2025

Total serum hemolytic complement (CH50) activity was determined for 3 semi-inbred strains of miniature swine (SLAa, SLAc, and SLAd) and 1 recombinant strain SLAg (ABCcDd), each homozygous for a distinct major histocompatibility complex haplotype. Initial determination was made at 8 weeks of age, prior to standardized immunization, the second at age 12 weeks, after immunization. Analysis of variance was by least-squares method, using a linear model on data from 33 litters by 14 sires and 16 dams. Analysis of variance indicated that the combined effects of haplotype, sire, dam, litter, and gender accounted for 47.63% of the total variation in preimmunization CH50 values. Dam (P ≤ 0.06) and litter (P ≤ 0.03) significantly influenced preimmunization complement activity. Although swine leukocyte antigen (sla) haplotype was not significant in the model, least-squares mean comparisons between haplotypes suggested that ac, dg, and gg pigs tended to have comparatively low preimmunization CH50 values. The model did not account for significant variability in postimmunization CH50 values, but least-squares means indicated that dd, dg, and gg haplotypes tended to have lower values than did other haplotypes tested. Mean CH50 units for 8- and 12-week-old pigs were 41.32 ± 20.49 and 59.50 ± 54.35, respectively. There was a significant difference (P < 0.001) in CH50 activity between 8- and 12-week-old pigs associated with immunization, because CH50 of nonimmunized controls did not differ at 8 and 12 weeks.
Cerebrospinal fluid analysis of rabid and vaccinia-rabies glycoprotein recombinant, orally vaccinated raccoons (Procyon lotor)
Authors: Hanlon Cathleen A. , Ziemer Ellen L. , Hamir Amir N. , Rupprecht Charles E.
Published: February 2025

Cerebrospinal fluid obtained from clinically normal free-ranging raccoons was analyzed and compared with csf obtained from raccoons vaccinated orally with vacciniarabies glycoprotein (v-rg) recombinant virus vaccine and subsequently challenged peripherally with street rabies virus, and csf from naive, rabies virus challenge-exposed control raccoons. Significant differences were not found in csf of free-ranging or v-rg recombinant virus vaccine recipient raccoons, and there was no evidence of cns invasion by v-rg virus. The csf of naive, rabies challenge-exposed control raccoons contained high numbers of lymphocytes and monocytes, compatible with rabies virus encephalitis. Although v-rg orally vaccinated challenge-exposed raccoons were protected from lethal rabies virus infection, a mild lymphocytic pleocytosis was evident at 90 days after challenge exposure.
Effects of ischemia and dimethyl sulfoxide on equine jejunal vascular resistance, oxygen consumption, intraluminal pressure, and potassium loss
Authors: Arden Warwick A. , Stick John A. , Parks Andrew H. , Chou Ching-Chung , Slocombe Ronald F.
Published: February 2025

Physiologic effects of 1 hour of ischemia and 1 hour of reperfusion on equine jejunum and protective effects of systemic administration of dimethyl sulfoxide (dmso, 1 g/kg of body weight) were investigated in 18 ponies, using neurally intact segments of jejunum perfused at constant flow with heparinized blood. Ponies were allotted to 4 groups: group 1, saline solution administered (control, n = 3); group 2, dmso administered (dmso, n = 3); group 3, ischemia induced and saline solution administered (ischemia, n = 6); and group 4, ischemia induced and dmso administered (ischemia-dmso, n = 6). Intestinal vascular resistance (r, mm of Hg/ml/min/100 g), oxygen consumption (Vo2, ml/min/100 g), frequency and amplitude of rhythmic changes in intraluminal pressure, intestinal compliance (c, ml/mm of Hg), and arteriovenous potassium concentration difference (Δav[K+], mEq/L) were determined and compared with stable preischemic values within groups. There were no significant changes in any variable in ponies of groups 1 or 2. In ponies of group 3, significant (P ≤ 0.05) changes included: an initial increase in r during reperfusion, followed by a decrease to values below preischemic values by 15 minutes of reperfusion; decreased Vo2 during the entire reperfusion period; increased amplitude of rhythmic contractions during initial reperfusion; decreased frequency of rhythmic contractions during ischemia; and increased Δav[k+] during initial reperfusion. Changes in ponies of group 4 were identical to changes in ponies of group 3, with the exception that dmso administration prevented the decrease in r during reperfusion. Although the action of dmso in modulating postischemic vascular reactivity may warrant further investigation, its failure to maintain tissue Vo2 or prevent tissue potassium loss suggested that dmso was not effective in preventing equine jejunal injury resulting from complete arterial occlusion followed by reperfusion.
Effect of clindamycin on Factor-VII activity in healthy cats
Authors: Jacobs Gilbert , Lappin Michael , Marks Amanda , Greene Craig E.
Published: February 2025

Four healthy cats were given clindamycin orally in daily doses of 25 or 50 mg/kg of body weight for 6 weeks. Significant change in Factor-VII activity was not found, compared with pretreatment values. In 2 cats tested, toxin produced by Clostridium difficile was not detected in fecal samples obtained before treatment and at 6 weeks after treatment, suggesting that intestinal overgrowth by C difficile did not develop. Results of the study seemed to indicate that orally administered clindamycin does not measurably reduce synthesis of vitamin K-dependent clotting factors in healthy cats.
Pharmacokinetics of sulfadiazine/trimethoprim in neonatal male calves: Effect of age and penetration into cerebrospinal fluid
Authors: Shoaf Susan E. , Schwark Wayne S. , Guard Charles L.
Published: February 2025

Sulfadiazine (sdz)/trimethoprim (tmp; 30 mg of sdz/tmp/kg of body weight) was given iv to the same 6 male calves at 1, 7, and 42 days of age and to 2 additional calves at 7 days of age. Serum concentrations of sdz and tmp were best represented by a 2-compartment open model, but in 42-day-old calves, csf concentrations of both drugs were best represented by a 1-compartment open model with first-order input. Between 1 and 42 days of age, the elimination half-life () of sdz decreased from 5.7 to 3.6 hours, and total body clearance (CLtot) increased from 1.43 to 1.88 ml/min/kg; the area under the curve (AUC0→∞) decreased from 291.5 to 225.4 mg/L·h. The distribution coefficient (Vd(area)/kg of body weight) decreased with age, changing from 0.72 to 0.59 L/kg, between 1 and 42 days of age.

Therapeutic concentrations of sdz in serum (> 2 μg/ml) were maintained for 24 hours in 1-day-old calves and for about 15 hours in 7- and 42-day-old calves. The elimination rate of tmp increased about 9-fold; was 8.4, 2.1, and 0.9 hours, respectively, at 1, 7, and 42 days of age. Other values also reflected an increase in tmp elimination rate with age: CLtot increased from 2.8 to 12 to 28.9 ml/min/kg, k13 increased from 0.336 to 0.654 to 1.664/h and AUC0→∞ decreased from 32.8 to 7.9 to 3.1 mg/L·h, respectively. Therapeutic concentrations (> 0.1 μg/ml) were maintained for 15 hours, 8 hours, and about 6 hours in 1-, 7-, and 42-day-old calves, respectively. Penetration of sdz and tmp into the csf in 42-day-old calves was substantial; ratios of AUCCSF/AUCserum were 0.60 and 0.69, respectively.

Therapeutic concentrations of drugs in csf were maintained if serum concentrations were above therapeutic concentrations; elimination rates of both drugs from the csf equaled those of serum. Sulfadiazine was excreted mainly unchanged; the percentage of dose excreted unchanged in 24 hours increased from 22.1 to 47.8 to 50.8% in 1-, 7-, and 42-day-old calves, respectively, paralleling the increase in CLtot. Trimethoprim was extensively biotransformed; the percentage of dose excreted unchanged in the urine in 24 hours decreased from 12.8 to 8.7 to 3.5%. Sulfadiazine and tmp were concentrated in the urine, and therapeutic concentrations of both drugs in urine were maintained for > 24 hours in calves of all ages.
Hematologic changes induced by intravenous administration of diacetoxyscirpenol in pigs, dogs, and calves
Authors: Coppock R. W. , Hoffmann W. E. , Gelberg H. B. , Bass D. , Buck W.B.
Published: February 2025

Diacetoxysscippenol (das) was given iv to pigs (0, 0.5, and 1.0 mg/kg of body weight), cattle (0 and 0.5 mg/kg), and dogs (0 and 0.5 mg/kg). Blood was collected and hemograms were done at 0.5-hour intervals for 8 hours. The animals were euthanatized at 8 hours after treatment, and bone marrow samples were taken and examined by light microscopy. Moderate to severe necrosis of bone marrow hematopoietic elements was found in animals given das. The sequential increase in the type and number of abnormal cells in the blood suggested a successive destruction of the hematopoietic elements. A marked left shift in the neutrophil population was found in animals given das. Metarubricytes and large platelets were found in the blood of animals given das. Lymphocytes were replaced with immature cells. Pathologic changes were most severe in the pigs given a dosage of 1.0 mg of das/kg. The order of species sensitivity to das was pigs > dogs >> cattle.
Pharmacokinetic properties of theophylline given intravenously and orally to ruminating calves
Authors: Langsten Vernon C. , Koritz Gary D. , Davis Lloyd E. , Neff-Davis Carol
Published: February 2025

The disposition of theophylline in healthy ruminating calves was best described by a first-order 2-compartment open pharmacokinetic model. The drug had a mean elimination half-life of 6.4 hours and a mean distribution half-life of 22 minutes. Total body clearance averaged 91 ml/kg/h. The mean values for the pharmacokinetic volume of the central compartment, pharmacokinetic volume of distribution during the terminal phase, and volume of distribution at steady state were 0.502, 0.870, and 0.815 L/kg, respectively.

Theophylline was readily absorbed after oral administration to the ruminating calf, with a mean fraction of 0.93 absorbed. The plasma concentrations after oral dosing peaked in approximately 5 to 6 hours, with a mean absorption half-life of 3.7 hours. A flip-flop model (rate constant of input is much smaller than the rate constant of output) of drug absorption was not found because the elimination process roughly paralleled that of the study concerning IV administration.

In a multiple-dose trial that used a dosage regimen based on single-dose pharmacokinetic values, clinically normal calves responded as predicted. However, diseased calves had higher than expected plasma concentrations after being given multiple oral doses of theophylline at 28 mg/kg once daily. Overt signs of toxicosis were not seen, but this aspect of the drug was not formally investigated.

Theophylline can be used as an ancillary therapeutic agent to treat bovine respiratory disease, but not without risk. The suggested oral dose of theophylline at 28 mg/kg of body weight once daily should be tailored to each case. Twice daily oral dosing at 20 mg/kg should reduce the plasma peak:trough ratio and provide plasma concentrations more consistently within the human therapeutic range of 10 to 20 μg/ml. Even then, therapeutic drug monitoring should be done.
Recombinant DNA probe for serotype-specific identification of bluetongue virus 17
Authors: de Mattos Cecilia C. , de Mattos Carlos A. , Osburn Bennie I. , Dangier Charles A. , Chuang Ronald Y. , Doi Roy H.
Published: February 2025

The double-stranded rna genome from 117 field isolates of bluetongue virus (btv) serotypes 10, 11, 13, and 17 was blotted onto nitrocellulose paper and hybridized with a radioactively labeled cloned copy of dna genome segment 2 of btv-17. Viral rna from btv prototype strains 2, 10, 11, 13, and 17 were used as controls. The probe hybridized only with the viral rna from prototype btv-17 virus and field isolates of btv-17. There was no cross hybridization with field isolates of btv serotypes 10, 11, and 13. A complementary dna probe developed from genes coding for btv serotype specificity was effectively used in a slot-blot hybridization system for efficiently characterizing the viral serotype.
Determination of brodifacoum and bromadiolone residues in rodent and canine liver
Authors: Ray Allen C. , Murphy Michael J. , DuVall Michael D. , Reagor John C.
Published: February 2025

A method to determine residue concentrations of anticoagulant rodenticides, brodifacoum (bf) and bromadiolone (bd) in liver was developed, using gas chromatography/mass spectrometry. Nine dogs were given 1.1 mg of bf/kg of body weight, po, in polyethylene glycol 400, one time. Rats were fed bf or bd (via commercial baits) in amounts from 0.28 to 11.25 mg/kg over 1- to 4-day periods. Fresh liver samples were collected at necropsy from all rats and 3 dogs, ground with Na2S04, and extracted with CHCl3:MeOH (9:1). After evaporation and silica cartridge purification were performed, residues were oxidized with a 0.16M chromic acid solution, and an oxidation product (4-bromobenzoic acid) was partitioned into CHCl3. The methylated derivative (port derivatization with trimethylanilinium hydroxide) was assayed, using gas chromatography/mass spectrometry. Bromadiolone was detected in livers from rats given > 6 mg of bd/kg of body weight, but not in livers of rats given 1.25 mg of bd/kg. In contrast, bf was detected (with one exception) in livers from dogs (given 1.1 mg of bf/kg) and from rats given high (11.25 mg of bf/kg) and low (0.28 mg of bf/ kg) doses. This protocol, which does not differentiate between bf and bd because of the formation of a common product after chromic acid oxidation, was used to diagnose anticoagulant toxicosis in 3 dogs, 1 human being and 1 llama naturally poisoned.
Type-I hypersensitivity as a component of eosinophilic myositis (muscular sarcocystosis) in cattle
Authors: Granstrom D. E. , Ridley R. K. , Baoan Yao , Gershwin L. J. , Nesbitt P. M. , Wempe L. A.
Published: February 2025

Eight bovine hearts with lesions of eosinophilic myositis (em) and 2 bovine hearts without em lesions were collected at slaughter. Blood samples from these 10 hearts, and the heart of a newborn calf also were collected. Histologically, Sarcocystis cruzi was identified in the 8 hearts with em lesions and the 2 hearts without em lesions, but not in the heart of the newborn calf.

Serum was harvested from the 10 blood samples and was used in homologous, modified, passive cutaneous anaphylaxis tests. Antigen was prepared from S cruzi bradyzoites isolated from the 2 hearts without em lesions. Serum samples from the 8 cattle with em lesions reacted positively to S cruzi antigen. When heat-inactivated IgE in serum (56 C for 4 hours) was used, all passive cutaneous anaphylaxis responses were considered negative. Using elisa, serum IgE concentrations from the 10 cattle with and without em lesions were 2.2 to 9 U/mL

As determined by radial immunodiffusion, IgM concentrations were 80 to 215 mg/dl. Immunoglobulin G concentrations were 420 to 2,050 mg/dl, but most were ≤ 1,700 mg/dl. Immunoglobulin A concentrations were 0 to 62 mg/dl; 1 steer with em lesions had 0 mg/dl.

Double-gel immunodiffusion confirmed the presence of Sarcocystis-specific precipitating antibodies. Sera from the 10 cattle with and without em lesions formed at least 1 precipitin band.
Variations in serum sorbitol dehydrogenase, aspartate transaminase, and isoenzyme 5 of lactate dehydrogenase activities in horses given carbon tetrachloride
Authors: Bernard William V. , Divers Thomas J.
Published: February 2025

Seven horses were given 0.5 mg of carbon tetrachloride/kg of body weight via a nasogastric tube. Subsequent hepatocellular damage was monitored by serum enzyme determinations of sorbitol dehydrogenase, isoenzyme 5 of lactate dehydrogenase, and aspartate transaminase activities. Creatinine kinase activity was evaluated as an indicator of muscle cell damage. Sorbitol dehydrogenase, isoenzyme 5 of lactate dehydrogenase, and aspartate transaminase activities were significanlty (P < 0.05) increased by 24 hours after carbon tetrachloride administration. Isoenzyme 5 of lactate dehydrogenase and sorbitol dehydrogenase activities returned to baseline several days before aspartate transaminase activity returned to baseline. Creatine kinase activity remained unchanged.
Analysis of muscle elements, water, and total lipids from healthy dogs and Labrador Retrievers with hereditary muscular dystrophy
Authors: Mehta Jagjivan R. , Braund Kyle G. , McKerrell Rosemary E. , Toivio-Kinnucan Maria
Published: February 2025

Skeletal muscles from healthy dogs and Labrador Retrievers with hereditary muscular dystrophy were examined morphologically and histochemically and were analyzed biochemically for Na+, K+, Ca2+, Mg2+, Zn2+, Cu2+, CI−, total muscle water, and total neutral lipid content. Flame atomic absorption spectrophotometer was used for elemental quantitation of hydrochloric acid tissue extracts. Muscle samples from dystrophic dogs contained substantially increased concentrations of Na+, Ca2+, Zn2+, Cu2+, and Cl−, and a considerable reduction in the content of K+ and Mg2+ compared with samples from healthy dogs. Total muscle water and total fat content was higher in muscles from dystrophic dogs. Most muscle samples from dystrophic dogs had a type-2 fiber deficiency and an increase in number of fibers with internalized nuclei.
DNA Homology of Brucella abortus strains 19 and 2308
Authors: Muzny Donna M. , Ficht Thomas A. , Templeton Joe W. , Adams Leslie G.
Published: February 2025

The restriction endonuclease digestion dna patterns from Brucella abortus strains 19 and 2308 were examined with 11 restriction enzymes (AvaI, BamHI, BglII, BstEII, DdeI, EcoRI, HindIII, KpnI, PstI, XbaI, and SalI). The dna electrophoretic banding patterns between the 2 strains were highly similar, using this restriction enzyme analysis. Differences were not discernable between B abortus strains 19 and 2308 in any of the restriction banding patterns examined. Methylation at ccgg or gatc sites was not detectable on the basis of digestion with isoschizomers (HpaII and MspI, and DpnI, Sau3AI and MboI).

Homology between B abortus strains 19 and 2308 was assessed, using solution-hybridization techniques followed by S1 nuclease assays. Results of these reassociation experiments indicated 98.6 to 99.3% homology between B abortus strains 19 and 2308 with 13.5 to 18.6% homology between B abortus (strains 19 and 2308) and the E coli HB101 control. We concluded that any dna differences between the 2 B abortus strains are small and will require analysis at the dna sequence level.
Characterization of outer membrane protein-enriched extracts from Pasteurella multocida isolated from turkeys
Authors: Choi K. H. , Maheswaran S. K. , Felice L. J.
Published: February 2025

Outer membrane protein (omp)-enriched extracts of avian strains of Pasteurella multocida were examined by use of sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Culture medium did not have a significant effect on the omp profiles of strains of P multocida examined; however, in vivo propagation had an appreciable effect on the omp profile composition of the reference strain P-1059. Such bacteria, expressed several additional omp in the 27-kD, 48-kD, 56-kD, 60-kD, 80-kD, and 94-kD molecular mass regions. These omp were not detected in the electrophorogram of strain P-1059 grown in vitro. The omp profiles of reference strains of the 16 serotypes of P multocida did not identify any serotype-specific protein markers. Field strains of serotype A:3 had variation in omp profiles and did not express omp that all were identical to that expressed by the reference strain P-1059. The live attenuated CU and M9 bacterial vaccine strains expressed strain-specific omp markers of 48-kD and 45-kD molecular masses, respectively. These strain-specific omp markers may be used to differentiate these strains from virulent field strains that are of the same serotype and isolated from turkeys that have succumbed to pasteurel-losis as a result of vaccine-related reactions or breakdown in immunity.