bluuebunny/crossref_metadata_2025 huggingface dataset:
Rabbit pasteurellosis: Induced disease and vaccination
Authors: Al-Lebban Z. S. , Corbeil L. B. , Coles E. H.
Published: February 2025

Pasteurellosis was induced in rabbits by conjunctival inoculation with 2 strains of Pasteurella multocida. The ld50 of strain P1062 (a bovine isolate) was 105.1 colony-forming units and that of strain P1059 (a turkey isolate) was 105.5 colony-forming units. Pasteurella-free rabbits were vaccinated iv or mucosally with boiled cells of P multocida or a cross-reactive uridine diphosphogalactose epimerase-deficient mutant of Escherichia coli J5.

In rabbits challenge exposed with P multocida strain 1062 or 1059, homologous P multocida strain gave the best protection against fatal bacteremia. Partial protection was provided by J5; mucosal routes of vaccination (aerosol or conjuctival) gave better protection than did the iv route. Serum antibody titers were lower in rabbits vaccinated by mucosal routes than in those vaccinated iv.

Cross-reactive IgG and IgM titers to P multocida were demonstrated when rabbits were vaccinated with J5. On the basis of bacteriologic examination of nasal secretions, rabbits that died were considered culture positive sooner than were those that survived. On the basis of bacteriologic examination of blood, rabbits that died were considered culture positive, and those that survived were considered culture negative. Seemingly, heat-stable antigens were protective, the cross-reactive E coli J5 mutant (with only core lipopolysaccharide) provided partial protection against pasteurellosis, and the mucosal route was somewhat useful for cross-protective immunization.
Serum bile acid analysis in dogs with experimentally induced cholestatic jaundice
Authors: Rutgers H. Carolien , Stradley Roger P. , Johnson Susan E.
Published: February 2025

Serum bile acid (sba) concentration was determined weekly for 4 weeks in dogs with experimentally induced hyperbilirubinemic liver disease. Obstructive jaundice was created in 6 dogs by surgical ligation of the common bile duct, and hepatocellular jaundice was created in 6 sham-operated dogs by administration of dimethylnitrosamine; 6 other sham-operated dogs served as controls.

Serum bile acid concentration increased rapidly after bile duct ligation (from 0.6 ± 0.1 to 69.2 ± 15.3 μmol/L at 3 days), peaked at 14 days (247.8 ± 54.1 μmol/L), and then gradually decreased (179.9 ± 27.1 μmol/L at 28 days). Serum bile acid concentration in dimethylnitrosamine-treated dogs increased more gradually to 38.9 ± 10.7 μmol/L at 28 days, at which time the serum bilirubin concentration was comparable with that of bile duct-ligated dogs. Mean total sba values in bile duct-ligated dogs were significantly (P < 0.01) higher than those in control and dimethylnitrosamine-treated dogs at days 3 through 28, with no overlap of individual values. Serum bile acid concentration at day 28 correlated positively (P < 0.01) with cholestasis and bile duct proliferation observed in liver biopsy specimens, but did not correlate with necrosis or inflammation. Serum bile acid concentration also correlated positively (P < 0.01) with serum bilirubin and cholesterol concentrations and with serum alkaline phosphatase and alanine transaminase activities.

Results of the study reported here indicated a relationship between sba concentration and cholestasis in dogs; extrahepatic bile duct obstruction resulted in the highest sba values. These findings indicate that total sba analysis may be a useful adjunct to routine liver function tests to differentiate between acute obstructive and hepatocellular jaundice in dogs.
Kidney biopsy: A nonlethal method for diagnosing Yersinia ruckeri infection (enteric redmouth disease) in rainbow trout (Salmo gairdneri)
Authors: Noga Edward J. , Levine Jay F. , Townsend Kimberly , Bullis Robert A. , Carlson Charles P. , Corbett Wayne T.
Published: February 2025

The sensitivity and specificity of kidney biopsy were 93 and 88%, respectively, for detecting Yersinia ruckeri infection in rainbow trout (Salmo gairdneri). There was no statistically significant difference between results obtained by kidney biopsy and those obtained by necropsy, the standard method for isolation of this agent from the kidney. One hundred percent of conscious fish that were tested survived the procedure.
Intramedullary pressure in canine long bones
Authors: Bauer Michael S. , Walker T. L.
Published: February 2025

Intramedullary pressure was measured bilaterally in 36 dogs: in the diaphysis and distal metaphysis of the femur, in the proximal metaphysis of the tibia and humerus, and in the diaphysis of the radius. Pressure measurements were repeated in 5 dogs, 14 days after the initial recordings.

Mean (± sd) pressures in the femoral diaphysis and distal metaphysis were 27.6 (± 15.4) mm of Hg and 17.6 (± 10.5) mm of Hg, respectively. Mean (± sd) pressures in the tibial diaphysis and proximal metaphysis were 26.4 (± 13.0) mm of Hg and 17.9 (± 11.8) mm of Hg, respectively. Mean (± sd) pressures in the humeral diaphysis and proximal metaphysis were 26.2 (± 15.8) mm of Hg and 13.4 (± 7.7) mm of Hg, respectively. The mean (± SD) pressure in the radial diaphysis was 15.4 (± 18.9) mm of Hg. Metaphyseal pressure was significantly (P < 0.05) lower than diaphyseal pressure. Repeated pressure measurements in 5 dogs did not vary significantly from initial values, suggesting that the wide range of pressure was real not artifactual.
Nontransmission of bluetongue virus by embryos from bluetongue virus-infected sheep
Authors: Hare W. C. D. , Luedke A. J. , Thomas F. C. , Bowen R. A. , Singh Elizabeth L. , Eaglesome M. D. , Randall G. C. B. , Bielanski A.
Published: February 2025

Donor sheep were infected either by bites of bluetongue virus (btv)-infected (serotype 11, “Texas Station strain”) Culicoides variipennis or by inoculation with 100,000 median chicken embryo intravascular lethal doses of btv (serotype 11) from a suspension made from infected C variipennis. Fourteen embryos from 4 btv-infected ewes bred by rams not infected with btv were transferred to 8 btv-seronegative recipient ewes, and 35 embryos and 4 unfertilized eggs from 14 btv-infected ewes bred by btv- infected rams were transferred to 19 btv-seronegative recipient ewes. Eleven pregnancies and 12 lambs resulted. None of the recipients or lambs seroconverted, and btv was not isolated from the pregnant recipient ewes or their lambs at slaughter 30 days after parturition.
Fixation procedures for retention of cellular morphologic features and for preservation of immunoreactivity of canine paramyxovirus antigens
Authors: Baumgärtner Wolfgang , Krakowka Steven
Published: February 2025

The effectiveness of 1% saponin at 55 C (sap), glutar-aldehyde-borohydride-saponin (gbs), and modified gbs (mgbs) as fixatives for preserving cellular morphologic features, as well as antigenicity of intracellular and membrane-bound viral proteins of canine parainfluenza virus (cpiv) and canine distemper virus (cdv) was studied. Use of the same fixatives for light and electron microscopic immunocytochemical examination also was investigated.

By light microscopy, cdv inclusions were readily detected after sap and mgbs fixation, but not after gbs fixation; cpiv inclusions were detected after gbs and mgbs fixation, but not after sap fixation. Ultrastructurally, sap-treated cells had moderate to severe cytoplasmic artifacts, although cdv-associated cytoplasmic and membrane viral antigens were readily labeled. The cpiv-infected cells contained only a few positively labeled membrane-associated antigens and cytoplasmic nucleocapsids (nc). Although gbs-treated cells had excellent ultrastructural preservation, immunolabeling was unsatisfactory; cpiv-nc were labeled incompletely, and cdv-nc were unlabeled. After fixation with mgbs, immunolabeling of NC and membrane-associated viral proteins for both viruses was achieved, and the architecture of infected cells was preserved.
Hemodynamic and respiratory responses in halothane-anesthetized horses exposed to positive end-expiratory pressure alone and with dobutamine
Authors: Swanson Clifford R. , Muir William W.
Published: February 2025

The influence of positive end-expiratory pressure (peep) on the alveolar-arterial O2 tension difference [P(a-a)o2, physiologic right-to-left shunt fraction, physiologic dead space-to-tidal volume ratio, and hemodynamic variables was studied in halothane-anesthetized horses maintained in dorsal recumbericy during controlled ventilation. Dobutamine was used to minimize the adverse cardiovascular consequences of peep. Six adult horses wore anesthetized, using xylazine (2.2 mg/kg of body weight, im), guaifenesin (50 mg/kg, iv). thiamylal Na (4.4 mg/kg, iv), and halothane (1.5 to 2% inspired) in 100% O2. Mechanical ventilation was controlled to maintain arterial eucapnia tor at least 45 minutes during base-line measurements. Hemodynamic and respiratory variables were determined every 15 minutes during equilibration. Each horse was subjected to 4 randomized treatments: 5cm of H2O peep, 10cm of H20 peep, 5cm of H2O peep plus dobutamine (1 μg/kg/min), and 10cm of H2O peep plus dobutamine (1 μg/kg/min). Each treatment lasted 15 minutes and immediately followed its predecessor. Although the magnitude of peep was randomized with and without dobutamine, peep without dobutamine always preceded peep with dobutamine.

Differences in hemodynamic or respiratory variables among base-line measurements, 5cm of H2O peep, or 10 cm of H2O peep were not significant (P > 0.05). Cardiac output, systemic and pulmonary arterial pressures, PaCO2 and end-tidal PCO2 were significantly (P < 0.05) increased, and arterial pH was decreased (P < 0.05) by 5cm of H2O plus dobutamine or by 10cm of H2O peep plus dobutamine, compared with values at base line and with 5cm or 10cm of H2O peep. Physiologic shunt fraction and physiologic dead space-to-tidal volume ratio were not significantly altered by 5cm of H2O peep plus dobutamine or by 10cm of H2O peep plus dobutamine, compared with base line ur with ocm or 10cm of H2O peep alone. The P(A-a)O2, was significantly (P < 0.05) decreased by 10cm of H2O peep plus dobutamine, compared with base line.
Moment analysis of multibreath nitrogen washout in healthy female goats and calves
Authors: Kiorpes Anthony L. , Clayton Murray K.
Published: February 2025

Moment analysis of multibreath nitrogen washout curves was performed for healthy female goats and calves. Curves were plotted, using dimensionless coordinates that minimized effects of alveolar ventilation changes. Results were expressed as the ratio of the first to the zeroth moments, μ1/μ2. Variability using this method was compared with that of a graphic analysis technique from which an uncorrected slope of a portion of the washout curve (b½) and a slope index corrected for lung and tidal volume (the nitrogen dilution constant) can be derived. Mean moment ratios on the basis of pooled data for 4 goats and 3 calves were 2.04 ± 0.29 and 2.38 ± 0.17, respectively. These values represent the weighted average number of times the resting lung volume was diluted with 100% O2; the lower the value, the relatively more uniform the distribution of intrapulmonary gas. The coefficient of variation within and between subjects was smallest using moment analysis and was greatest for the B½. Variability expressed as sd was similar between the moment ratio and nitrogen dilution constant and was greatest for the B½.
Pharmacokinetics of tobramycin in cats
Authors: Jernigan Antoinette D. , Hatch Roger C. , Wilson Robert C.
Published: February 2025

Tobramycin was administered to cats and its serum concentration vs time data were analyzed by use of a noncompartmental model. In the first experiment, 5 mg of tobramycin/kg of body weight was administered iv, im, and then sc to 6 cats, 3 weeks apart. After iv administration, the mean ± sd total body clearance of tobramycin was 2.21 ± 0.59 ml/min/kg, and the apparent volume of distribution at steady state was 0.19 ± 0.03 L/ kg. The mean residence time was 90.5 ± 16.2 minutes, with a harmonic mean serum half-life of 68.9 ± 9.7 minutes. Blood urea nitrogen and serum creatinine concentrations were increased 3 weeks after the iv injection and also 3 weeks after the im injection, which suggested possible renal damage. Moreover, large area under the curve values developed after im and sc administrations, resulting in bioavailabilities of 159.5% and 189.9%, respectively, with no change in elimination rate. These results suggested a change in distribution, possibly caused by saturation of renal binding sites by residual tobramycin from the previous injection of 5 mg/kg.

In experiment 2, 6 other cats were given 3 mg of tobramycin/kg by the same routes as before, but using a crossover design. Bioavailability after im and sc administrations was 102.5% and 99.2%, respectively, indicating complete absorption of tobramycin. The bun concentration increased in 3 cats, and serum creatinine concentration increased in 1 of these 3 cats. After iv administration of 3 mg of tobramycin/kg, the total body clearance was 1.69 ± 0.36 ml/min/kg, the apparent volume of distribution at steady state was 0.18 ± 0.003 L/kg, mean residence time was 107.6 ± 20.7 minutes, and half-life was 110.6 ± 32.3 minutes.

The results were an indication that nephrotoxicosis develops when cats are given smaller doses of tobramycin than those reported previously. In addition, tobramycin pharmacokinetics may be dose dependent. On the basis of the pharmacokinetic values from this study, however, the average steady-state serum tobramycin concentration after administration of 2 mg of tobramycin/kg, q 8 h, was calculated to be 3 to 4 μg/ml, with a peak serum concentration of 11 μg/ml and a trough concentration of 0.15 μg/ml. These concentrations are antibacterial for many tobramycin-sensitive bacteria and may be subtoxic in clinically normal cats.
Pathologic changes and tissue gentamicin concentrations after intravenous gentamicin administration in clinically normal and endotoxemic cats
Authors: Jernigan Antoinette D. , Hatch Roger C. , Wilson Robert C. , Brown John , Crowell Wayne A.
Published: February 2025

Hematologic and serum biochemical values tissue, gentamicin concentrations, and renal pathologic changees were determined in clinically normal and endotoxemic cats given 3 mg of gentamicin/kg of body weight, iv. Endotoxemia was induced by iv administration of 0.5 μg of Escherichia coli endotoxin/kg of body weight. In experiment 1, 6 cats were given endotoxin. After rectal temperature increased at least 1° C, cats were given gentamicin. Blood samples were collected before and at 1 and 3 hours after administration of gentamicin. With the exception of severe leukopenia, other hematologic changes or changes in serum biochemical values were not observed.

In experiment 2, 24 cats were allotted to 4 groups and were given gentamicin, endotoxin, gentamicin plus endotoxin, or neither substance. Three hours later, cats were euthanatized, and tissue and body fluid specimens were obtained and were assayed for gentamicin concentration. Kidney specimens were examined microscopically. Endotoxemic cats had more gentamicin in the renal medulla than did control cats, but none of the cats had detectable renal lesions. The possible nephrotoxic synergism between gentamicin and severe endotoxemia and the lack of major differences in gentamicin concentration in extrarenal tissues indicated that the dosage of gentamicin in endotoxemic cats does not have to exceed the dosage recommended for clinically normal cats. A single dose of gentamicin administered iv did not cause renal damage in mildly endotoxemic cats, but nephrotoxicity ascribed to multiple doses of gentamicin in more severely endotoxemic cats needs to be evaluated.
Effect of gentamicin sulfate and sodium bicarbonate on the synovium of clinically normal equine antebrachiocarpal joints
Authors: Lloyd K. C. Kent , Stover Susan M. , Pascoe John R. , Pool Roy R , Kurpershoek Cornelis
Published: February 2025

The effect of gentamicin sulfate, unbuffered and buffered with sodium bicarbonate, on synovial fluid and membrane of clinically normal equine joints was evaluated. Thirty-six adult horses with clinically normal antebrachiocarpal joints were allotted to 6 treatment groups of 6 horses each. One antebrachiocarpal joint in each horse was chosen for treatment. Group-1 horses were given gentamicin (3 ml; 50 mg/ml); group-2 horses were given sodium bicarbonate (3 ml; 1 mEq/ml); group-3 horses were given gentamicin (3 ml; 50 mg/ml) and sodium bicarbonate (3 ml; 1 mEq/ml); group-4 horses were not treated; and horses of groups 5 and 6 were given polyionic physiologic solution (3 and 6 ml, respectively). Synovial fluid specimens were obtained from 5 horses of each group for cytologic analysis at postinjection hours (pih) 0, 24, 72, and 192 and for pH determination at pih 0, 0.25, 0.5, 1, 4, 8, 24, 72, and 192. The sixth horse of each group was euthanatized at pih 24, and the synovial membrane of the treated and contralateral (nontreated) antebrachiocarpal joints was examined macroscopically and microscopically.

After intra-articular gentamicin administration, the mean synovial fluid pH was lowest (5.98) at pih 0.25, but by PIH 8, it was not significantly different from the control value (group-5 horses). When sodium bicarbonate was combined with gentamicin before intra-articular administration, the mean synovial fluid pH was lowest (7.07) at pih 0.25, but by pih 1, it was not significantly different from the control value (group-6 horses). The mean synovial fluid wbc count was significantly (P < 0.05) greater 24 hours after buffered gentamicin treatment (14,120 cells/μl) than after treatment with gentamicin alone (4,440 cells/μl), and predominantly large mononuclear cells were observed. Resolution of the cellular inflammatory response was observed by pih 72 after administration of buffered gentamicin or gentamicin alone. In all groups, significant difference in synovial fluid neutrophil or rbc count from control value (groups 5 and 6) was not observed.

In horses of all age groups, appreciable difference in the macroscopic appearance of the light pink to salmoncolored mucosa of the synovial membrane was not detected between the treated and nontreated antebrachiocarpal joints. Synovitis was detected in the joint capsules treated with buffered gentamicin, unbuffered gentamicin, and sodium bicarbonate. In each instance, the palmarolateral pouch of the antebrachiocarpal joint was more inflamed than was the dorsal portion of the joint capsule, probably because the palmarolateral pouch was the site for placement of the catheter and intra-articular drug administration. The quality of the inflammation was more compatible with trauma or irritation than with sepsis.
Comparative study of assays for stimulated fluid pinocytosis in canine and human neutrophils
Authors: Langweiler Marc , Davis Bruce H.
Published: February 2025

We compared a flow cytometric assay of fluid pinocytosis in stimulated neutrophils with previously used methods, including spectrophotofluorometric assay of fluoresceinated dextran (fd) uptake and β scintillation spectroscopic assay of radiolabeled sucrose uptake. Neutrophils from human and canine blood were stimulated with formyl-methionyl-leucyl-phenylalanine and phorbol myristate acetate, respectively. Flow cytometry was used to quantitate uptake of fd and lucifer yellow, spectrophotometry was used to quantitate uptake of fd, and spectroscopy was used to quantitate uptake of 14C-labeled sucrose. The flow cytometric assay, using either fd or lucifer yellow, was found to be superior on the basis of maximal incremental increase observed, minimal variability within replicate experiments, and maximal sensitivity to detect early stimulation of fluid pinocytosis in neutrophils.
Partial purification and characterization of bovine fibroblast interferon
Authors: Allen G. K. , Grothaus G. D. , Rosenquist B. D.
Published: February 2025

Bovine fibroblast interferon (BoF-ifn), produced in primary bovine embryonic kidney cell cultures after priming and infection with bluetongue virus, was purified by controlled pore glass (cpg) chromatography to a specific activity of 106 U/mg of protein, with 40% recovery of the original activity. The crude ifn was concentrated more than sevenfold during purification. This proved to be a relatively simple, practical method of obtaining sufficient quantities of partially purified natural BoF-ifn for further studies.

The cpg-purified BoF-ifn was further concentrated by sequential ultrafiltration and was analyzed by sodium dodecyl sulfate/polyacrylamide-gel electrophoresis (sds-page). Interferon, recovered from denaturing conditions either by dialysis against phosphate-buffered saline solution or by dilution in cell culture medium containing 10% fetal bovine serum, migrated as a single stainable protein with molecular weight of 21,000 on analytic sds-page gels. Recovered ifn activity from preparative sds-page totalled 8.7% of that applied.

Attempts to further purify cpg-purified BoF-ifn by zinc chelate affinity chromatography were unsuccessful.
Ecologic study of the risk factors for environmental mastitis in cows
Authors: Schukken Ynte Hein , Erb Hollis N. , Sears Philip M. , Smith R. David
Published: February 2025

An index was developed to measure the proportion of intramammary infections caused by environmental microorganisms on dairy farms. This environmental index can be interpreted as the probability that an intramammary infection was caused by an environmental pathogen, rather than by a contagious pathogen.

Using the environmental index as the outcome variable, risk factors for environmental mastitis were studied on 10 dairy farms in New York. Turning the cows outside was associated with lower environmental index, and having cows drink from a stream increased the environmental index. Selective (rather than uniform) nonlactating cow intramammary treatment was related to a lower environmental index (apparently because the farms practicing selective nonlactating cow treatment suffered from epizootics of contagious mastitis).
Morphologic alterations observed during experimental ischemia of the equine large colon
Authors: Snyder Jack R. , Olander Harvey J. , Pascoe John R. , Holland Melissa , Kurpershoek Cornelis J.
Published: February 2025

Morphologic changes that develop sequentially in the large colon during experimentally induced ischemia were documented in 14 halothane-anesthetized horses. Colonic ischemia was induced by 4 types of vascular occlusion, 24 cm proximal and distal to the pelvic flexure. The effect of transmural (colonic wall) vascular compression combined with either venous occlusion (3 horses, group A) or venous and arterial occlusion (3 horses, group B) of the colonic vessels was studied for 1, 2, and 6 hours of occlusion. Also observed was the effect of reperfusion for 0.5 hour after release of the clamps for the 1- and 2-hour occlusions and for 1 hour after release of the clamps for the 6-hour occlusion. Effects of occluding only the colonic veins (4 horses, group C), or the colonic veins and arteries (4 horses, group D) were studied for 0.5, 1, 1.5, and 2 hours of occlusion and during reperfusion for 0.5 hour.

Full-thickness intestinal biopsy specimens were obtained from the antimesenteric border of the pelvic flexure at 0, 0.25, 0.5, 0.75, 1, 1.5, and 2 hours during occlusion and at 0.5 hour after release of vascular occlusion. Biopsy specimens were obtained at hourly intervals from the 2 horses in which 6-hour occlusion was performed and at 1 hour after release of vascular occlusion. Macroscopic changes (serosal color, mucosal color, serum leakage) in the colon were recorded. Histologic criteria were determined on the basis of degree of hemorrhage and edema (score severity ranged from 0 to 4), the interstitium-to-crypt ratio (normal I:C was ≤ 1), and the percentage of luminal and crypt epithelial alterations. In group-A horses, the serosal and mucosal color changed rapidly; after 4 hours of ischemia, they were purple and black, respectively. The epithelial alterations progressed until by 4 hours of ischemia, 95 to 100% of the luminal and crypt surfaces were affected. The I:C increased to 5:1 by 5 hours of ischemia.

In group-B horses, the serosal color initially turned blue gray and then progressed to purple by 5 hours of ischemia, while the mucosal color changed from dark red to black by 4 hours. The histologic changes were similar to those of group-A horses; however, the I:C did not increase ≥ 3:1, and the crypt epithelial alterations did not exceed 95%. Similar, but less severe, changes were seen in horses of groups C and D. These results suggested that 3 to 4 hours of severe ischemia induced by transmural compression, combined with either type of vascular occlusion, probably will cause irreversible destruction of the normal colonic mucosa.
Early mucosal healing and chronic changes in pony jejunum after various types of strangulation obstruction
Authors: Freeman David E. , Cimprich Ronnie E. , Richardson Dean W. , Gentile Dennis G. , Orsini James A. , Tulleners Eric P. , Fetrow John P.
Published: February 2025

Strangulation obstruction was induced in anesthetized ponies for periods of 2 and 3 hours by clamping 45-cm segments of jejunum and their veins only (venous strangulation obstruction, vso) and arteries and veins (arterial and venous strangulation obstruction, avso). These types of strangulation obstruction were studied in 4 segments in each of 4 ponies allowed to survive 12 hours (group 1) and in a single segment in each of 10 ponies allowed to survive 42 days (group 2) after the strangulation period ended.

On visual inspection, segments subjected to vso had hemorrhage and edema in the bowel wall and mesentery and were dark purple after all time intervals. They improved slowly after clamps were removed, but remained hemorrhagic and edematous. Segments subjected to avso were purple and had mild edema and scattered petechiae in the bowel wall and mesentery. They improved rapidly and closely resembled normal bowel after 5 minutes of reperfusion.

On light and scanning electron microscopy, the mucosa of intestine subjected to vso and avso had necrotic, denuded villi 1 hour after the strangulation periods ended. Twelve hours after removal of occlusion devices in group-1 ponies, 4 (25%) segments were unchanged, 4 (25%) had deteriorated, and 8 (50%) had stunted villus remnants partly or completely lined with regenerating epithelium. Separation and detachment of villus tip mucosal cells were seen in 3 of 4 control segments, 1 and 12 hours after the strangulation periods ended. At necropsy, all ponies in group 2 had normal test segments, except for 1 that had stricture at a previous clamp site. In 2 ponies that had segments subjected to 3 hours of vso, the mesentery was short and thick between the points where vascular clamps had been applied.

These findings suggest that brief periods of strangulation obstruction can induce severe gross changes in the intestinal wall, but that necrosis can be limited to the villus tip cells in the strangulated segment and, to a lesser degree, in nonstrangulated segments of jejunum. Mucosal repair was characterized by reepithelialization of stunted villi at 12 hours after the ischemic injury and these villi acquired normal length and architecture some time later. The rare long-term effects of ischemia were largely confined to the mesentery and were attributed to the effects of hemorrhage and edema.
Experimental definition of latissimus dorsi, gracilis, and rectus abdominus musculocutaneous flaps in the dog
Authors: Gregory C. R. , Gourley I. M. , Koblik P. D. , Patz J. D.
Published: February 2025

Dissection and injection studies in canine cadavers and in anesthetized dogs were conducted to determine the feasibility of using the latissimus dorsi, gracilis, and rectus abdominus muscles as musculocutaneous free flaps. Lengths of vascular pedicles for the latissimus dorsi (2 ± 0.8 cm), gracilis (1.8 ± 0.8 cm), and rectus abdominus (1.9 ± 0.9-cm cranial deep epigastric, 1.7 ± 0.5-cm caudal deep epigastric), as well as arterial diameters (1.28 ± 0.31-mm thoracodorsal for the latissimus dorsi, 1.10 ± 0.33-mm muscular branch for the gracilis, 1.25 ± 0.25-mm cranial deep epigastric and 1.26 ± 0.32-mm caudal deep epigastric for the rectus abdominus) were considered satisfactory for microvascular transfer.

Fluorometry demonstrated overlying cutaneous perfusion in all flaps based on their muscle vascular pedicles, with the exception of the rectus abdominus flap based on the caudal deep epigastric artery. In this instance, up to 20% of the cutaneous element had questionable or no perfusion.
Histologic features of the healing of bone graft donor sites in dogs
Authors: Johnson Kenneth A.
Published: February 2025

Healing of cancellous bone graft donor sites in the proximal tibial metaphysis of 12 healthy adult dogs was studied histologically. Cancellous bone was curetted from the metaphysis of the proximal end of the tibia, via a 1-cm diameter circular opening in the medial cortex. A hematoma and fibrovascular tissue filled the bone defect at 2 weeks. At 4 and 8 weeks, endosteal callus, composed initially of cartilage and woven bone and later of lamellar bone, filled the marrow cavity. At 12 weeks, the normal structural arrangement of lamellar bone and hematopoietic marrow was reestablished in the marrow cavity. The medial cortex defect was filled only with lamellar trabecular bone. It was concluded that, in adult dogs, a second cancellous bone graft could be collected from the proximal portion of the tibial metaphysis 12 weeks or more after an initial collection.
Response of pony peritoneum to four peritoneal lavage solutions
Authors: Schneider Robert K. , Meyer Dennis J. , Embertson Rolf M. , Gentile Dennis G. , Buergelt Claus D.
Published: February 2025

Peritoneal lavage was performed on ponies to determine the effect on peritoneal surfaces. Lavage solution (20 L) was introduced into each pony's peritoneal cavity through catheters placed in the paralumbar fossa, and the solution was removed by drainage from the ventral portion of the abdomen. Six ponies each were lavaged wth sterile saline (0.9% NaCl) solution, sterile saline solution containing 5 × 106 U of potassium penicillin and 3 g of neomycin or povidone-iodine diluted to 3% by volume with sterile saline solution, and 3 ponies were lavaged with povidone-iodine diluted to 10% with sterile saline solution. Peritoneal lavage catheters were inserted in 3 control ponies, but lavage fluids were not administered. Peritoneal fluid specimens were collected at 6, 24, 48, and 96 hours after lavage. Nucleated cell counts, rbc counts, total protein determinations, and cytologic analysis were performed. The ponies were euthanatized at 96 hours, and representative sections of the peritoneum were examined. Lavage with saline solution and saline solution with antibiotics induced a mild, transient inflammatory response in the peritoneal fluid, with minimal or no changes observed at necropsy. Solutions containing povidone-iodine induced chemical peritonitis, which was severe in ponies lavaged with 10% povidone-iodine solution. Peritoneal lavage with povidone-iodine solutions as dilute as 3% cannot be accomplished without causing inflammation of peritoneal surfaces.
Distribution of chloramphenicol in the genital tract of postpartum cows
Authors: Bretzlaff K. N. , Ott R. S. , Koritz G. D. , Lock T. F. , Neff-Davis C. A , Gustafsson B. K. , Davis L. E.
Published: February 2025

Chloramphenicol was administered by constant iv infusion to 7 healthy postpartum cows at rates predicted to approach a steady-state plasma concentration of 5 μg/ml. After 8 hours of constant iv infusion, uterine tissues were removed surgically and were assayed for chloramphenicol concentrations. Mean plasma-to-tissue ratios of chloramphenicol concentrations were 3.05, 3.63 (6 cows only), and 3.22 for caruncles, endometrium, and uterine wall, respectively. Plasma-to-tissue ratios of the 3 tissues were not significantly different (P > 0.10).

Intrauterine (iu) injections of chloramphenicol (20 mg/kg of body weight) were administered to 3 healthy postpartum cows. The mean value of the fraction of the drug absorbed from the uteri of these cows was 0.40. Mean concentrations of chloramphenicol were 43.8 μg/g in caruncles, 34.6 μg/g in endometrium, 2.8 μg/g in uterine wall, and 2.9 μg/ml in plasma 8 hours after iu injections.

Chloramphenicol has now been banned for use in food-producing animals in the United States because of its potential for causing toxicosis in human beings. It is illegal to use chloramphenicol in food-producing animals in the United States and in some other countries as well. This includes use by the iu route of administration because chloramphenicol and most drugs are absorbed from the uterus into the bloodstream and are distributed to milk and tissues.
Quality control criteria for quantitative enzyme-linked immunosorbent assay of porcine immunoglobulins A and M
Authors: Kelley Keith W. , Kleiss Alice J. , Brief Susan
Published: February 2025

Using radioimmunoassay methods, quality control criteria were applied to monoclonal antibodies produced to measure porcine immunoglobulins by quantitative elisa. Porcine IgM and IgA were purified to homogeneity and were used to produce murine hybridomas that secreted antibodies against IgM, IgA, and immunoglobulin light chains. A competitive elisa was developed to measure IgM, and a sandwich elisa was used to quantify IgA in serum and colostrum. Both elisa were tested for specificity, accuracy, sensitivity, and precision. Monoclonal antibodies were specific for porcine IgM or IgA in serum and colostrum, and competitive and sandwich elisa fulfilled all validation criteria.
Multielement assay of perinatal lamb livers by inductively coupled argon plasma emission spectroscopy
Authors: van Selm Gijs , Rook Joseph S. , Slanker Michael , Bartlett Paul C. , Braselton W. Emmett
Published: February 2025

During the 1986 lambing season, 33 Michigan sheep producers submitted all lambs that had died before weaning to the Michigan State University Diagnostic Laboratory for necropsy. Inductively coupled argon plasma emission spectroscopy was used to measure 22 elements in the liver of 888 of the lambs submitted. Mean concentrations of each element were established and compared with literature values of established deficient, normal, and toxic concentrations.

Mean values in milligrams per kilogram of wet weight were as follows: Al, 3.843; As, < 1; Ba, 0.176; Ca, 128.2; Cr, 0.778; Cu, 56.82; Fe, 491.6; Hg, < 2; K, 2,150; Mg, 138.4; Mn, 2.776; Mo, 0.489; Na, 1,384; P, 2,583; Pb, 1,453; Sb, < 1; Tl, < 5; Zn, 68.31. In only 11 lambs did the liver contain As, B, Cd, Co, Hg, Sb, Se, or Tl in detectable concentrations.
Relationship of days in gestation at exposure and development of brucellosis in strain 19-vaccinated heifers
Authors: Crawford Richard P. , Adams L. Garry , Williams John D.
Published: February 2025

Heifers injected with 108 (n = 40), 109 (n = 39), or 1010 (n = 39) colony-forming units of Brucella abortus strain 19 were conjunctivally exposed to 107 colony-forming units of strain 2308 during gestation. At parturition, milk from each quarter of the udder, a piece of placenta, and 2 swab specimens of the uterus from the dam plus a swab specimen of the rectum from each calf were cultured for Brucella. If the calf was dead or died, additional specimens of lung, stomach contents, and a mediastinal lymph node also were cultured. Days in gestation was determined for each heifer, using data from rectal palpation after breeding and crown-rump length and weight of calf at parturition, with the median value used for data analysis. In each vaccine dosage group, the proportion (%) of heifers developing brucellosis increased as days in gestation at exposure increased. Strain 2308 was isolated from 3 (11%) of 26, 16 (25%) of 64, and 18 (64%) of 28 heifers that were grouped as < 121, 121 to 150, and > 150 days in gestation at time of exposure, respectively. Thirty-two (86%) of the 37 infected heifers were < 260 days in gestation at parturition, and calves were premature. Heifers with premature calves were more likely to be infected, and tissues were more likely to yield multiple isolations of strain 2308, regardless of days in gestation at exposure or of days after exposure to parturition. Days after exposure to premature parturition of infected heifers ranged from 35 to 110.
Viral and viral protein specificity of antibodies induced in cows persistently infected with noncytopathic bovine viral diarrhea virus after vaccination with cytopathic bovine viral diarrhea virus
Authors: Bolin Steven R.
Published: February 2025

Neutralizing and nonneutralizing antibodies to bovine viral diarrhea (bvd) virus were detected in 3 cows persistently infected with noncytopathic bvd virus after vaccination with modified-live cytopathic bvd virus. Neutralizing antibodies detected in serum samples from each persistently infected cow at 3 weeks after vaccination were highly specific for certain isolates of cytopathic bvd virus and reacted only with a viral protein with a molecular weight of 53,000. Neutralizing antibodies to 1 of 3 isolates of noncytopathic bvd virus were detected in a serum sample obtained at 12 weeks after vaccination from 1 of 3 persistently infected cows. Nonneutralizing antibodies were detected in all cows at 7 to 12 weeks after vaccination. The nonneutralizing antibodies were less specific for isolates of bvd virus and reacted with viral proteins with molecular weights of 115,000, 80,000, 53,000, and 47,000.
Isolation and characterization of epizootic hemorrhagic disease virus from sheep and cattle in Colorado
Authors: Thompson Lee H. , Mecham James O. , Holbrook Frederick R.
Published: February 2025

Epizootic hemorrhagic disease virus was isolated from cattle and sheep in northeastern Colorado during July and August 1984. The isolates were identified as serotype 2 by plaque-inhibition serotyping, genome electropherotyping, and protein analysis.
Pharmacokinetics, metabolism, and renal clearance of sulfadiazine, sulfamerazine, and sulfamethazine and of their N4-acetyl and hydroxy metabolites in calves and cows
Authors: Nouws J. F. M. , Mevius D. , Vree T. B. , Baakman M. , Degen M.
Published: February 2025

The effect of molecular structure on the drug disposition and protein binding in plasma and milk, the urinary recovery, and the renal clearance of sulfadiazine, sulfamerazine, and sulfamethazine and of their N4-acetyl and hydroxy derivatives were studied in calves and cows. Sulfadiazine was highly acetylated and was slightly hydroxylated. Sulfamerazine and sulfamethazine were hydroxylated predominantly at the methyl group of the pyrimidine side chain; hydroxylation of the pyrimidine ring itself was more extensive for sulfamethazine than for sulfamerazine. At dosages between 100 and 200 mg/kg of body weight, sulfamethazine had a capacity-limited elimination pattern, which was not observed for sulfadiazine or sulfamerazine. The concentrations of the parent sulfonamide and its metabolites in plasma and milk were parallel, the latter being lower. Metabolite concentrations in milk were at least 8 times lower than those of the parent drug. Metabolism speeds drug elimination, producing compounds with renal clearance values higher than those of the parent drug. The effect on the metabolism and renal clearance of methyl substitution in the pyrimidine side chain is discussed.
Immune response of pregnant heifers and cows to bovine rotavirus inoculation and passive protection to rotavirus infection in newborn calves fed colostral antibodies or colostral lymphocytes
Authors: Archambault Denis , Morin Guylaine , Elazhary Youssef , Roy Raymond S. , Joncas Jean H.
Published: February 2025

The efficacy of an adjuvanted bovine rotavirus vaccine in pregnant cattle (15 heifers and 2 cows) was studied. Each of 4 animals was inoculated im at 8, 5, and 2 weeks before parturition with a water-in-oil emulsion containing live purified bovine rotavirus, mineral oil, and a mannide oleate compound. Four other animals were treated identically, except that muramyl dipeptide was added to the virus preparation. Five additional animals were inoculated orally at the same time intervals with adjuvant-free viral suspension, and 4 other pregnant animals inoculated only with buffer served as uninoculated controls. Kinetic studies of the specific immune responses were determined by quantification of the rotavirus-neutralizing antibodies and by a rotavirus lymphocyte stimulation test in vitro. Results showed that only the emulsions induced marked enhancement of rotavirus antibody titers in the serum, colostrum, and milk of inoculated cows. Colostral and milk lymphocytes isolated from these cows had a positive in vitro proliferative response to rotavirus stimulation, which lasted at least 21 days after parturition. The values of the stimulation index obtained with the colostral/milk lymphocytes were higher than those of the blood lymphocytes, reflecting increased lymphocyte activity in the colostrum/milk. However, addition of muramyl dipeptide to the emulsion preparation did not exert any potentiating effect on the immune response to rotavirus.

Calves fed for the first 5 days after birth with a rotavirus-immune cell-free colostrum supplement were protected from a rotavirus challenge exposure on the third day after birth. Virus was not detectable in their feces. In contrast, calves inoculated orally with 107 day-1 colostral mononuclear cells, obtained from cows inoculated with either emulsion, and challenge exposed 24 hours later shed rotavirus particles in their feces. However, these calves excreted virus for a shorter time, compared with controls. It was concluded that the use of mineral oil and a mannide oleate compound may be useful to enhance the humoral and cellular immune responses against bovine rotavirus in cows.
Nasal lesions in rats exposed to hydrogen sulfide for four hours
Authors: Lopez Alfonso , Prior Michael , Yong Shirley , Lillie Leonard , Lefebvre Marlene
Published: February 2025

Fischer-344 rats were exposed for 4 hours to 0, 14, 280, or 560 mg of hydrogen sulfide·m-3 and killed 1, 18, or 44 hours later. We evaluated the nasal epithelial cells and determined the anatomic distribution of lesions. Inhalation of 560 mg of hydrogen sulfide·m-3 induced necrosis and exfoliation of respiratory and olfactory mucosal cells, but not squamous epithelial cells. The anatomic distribution of lesions was midway along the nasal passages involving nasal and maxillary conchae, but not ethmoidal conchae. Injured respiratory mucosa repaired rapidly, whereas olfactory mucosa continued to exfoliate at 44 hours after exposure.
Transsphenoidal hypophysectomy in the clinically normal dog
Authors: Lantz Gary C. , Ihle Sherri L. , Nelson Richard W. , Carlton William W. , Feldman Edward C. , Lothrop Clint D. , Bottoms Gerald D.
Published: February 2025

Pituitary function and short-term clinical effects after transsphenoidal hypophysectomy were investigated in clinically normal dogs. In study I, 8 dogs were given polyionic fluids iv during the first 12 hours after surgery. In study II, 4 dogs were given polyionic fluids iv and glucocorticoid supplementation for 7 days. Pituitary function was assessed by evaluating basal acth concentrations and results of a growth hormone stimulation test before and 1 and 12 weeks after hypophysectomy, an acth stimulation test, a thyrotropin-releasing hormone-stimulation test, and a modified water deprivation/vasopressin response test before and 1, 4, 8, and 12 weeks after hypophysectomy. Gross and histologic evaluations of the surgery site, thyroid and adrenal glands, and skin were done at 12 weeks after surgery.

Four dogs from study I died within 27 hours after hypophysectomy. Postmortem examinations of these dogs revealed liver and lung congestion compatible with circulatory collapse. None of the dogs in study II died. For the surviving dogs in both studies, diabetes insipidus developed immediately after hypophysectomy and resolved within 2 weeks. Hypernatremia also developed immediately after hypophysectomy and resolved by 1 week. Production of acth was evident at 1 and 12 weeks after hypophysectomy in all dogs, and results of acth stimulation tests after surgery were not notably different from results obtained before surgery. Results of thyrotropin-releasing hormone stimulation and growth hormone-stimulation tests supported the diagnosis of hypothyroidism and hyposomatotropism attributable to hypophysectomy. Histologic examination revealed thyroid atrophy, epidermal and dermal atrophy, and normal adrenal glands in all dogs and remnants of the hypophysis in 2 dogs from study I. Continued acth production suggested that complete hypophysectomy was not accomplished in any dog.
Comparison of G-banded chromosomes from clinically normal lambs and lambs affected with ovine hereditary chondrodysplasia (spider syndrome)
Authors: Vanek Jerome A. , Bleier William J. , Whited Dean A. , Alstad A. D.
Published: February 2025

Lymphocytes from 5 clinically normal lambs and 5 lambs affected with ovine hereditary chondrodysplasia (spider syndrome) were cultured, G-banded, and karyotyped. Fifty metaphase karyotypes and one heterogram were evaluated for chromosome number and morphologic features. All lambs had normal diploid (2n) chromosome numbers of 54,XX or 54,XY, and there were no apparent differences in the morphologic features of the chromosomes.
Enzyme-linked immunosorbent assay for canine serum ferritin, using monoclonal anti-canine ferritin immunoglobulin G
Authors: Weeks Bradley R. , Smith Joseph E. , Phillips Robert M.
Published: February 2025

Immunoassay of serum ferritin is currently used to evaluate the clinical iron status of human beings, horses, cattle, and swine. Because ferritins are immunologically species specific, a separate assay must be developed for each species. We have developed an elisa for serum ferritin in dogs, using a monoclonal anti-canine ferritin antibody. Ferritin standards were linear (r = 0.997) from 0 to 80 ng/ml. Recovery of ferritin from canine serum was 94%. Dilutions of pooled canine serum were linear from 0 to 50% (r = 0.994). Within-assay coefficient of variability was 5.5%, whereas assay-to-assay coefficient of variability ranged from 12.5 to 21%. This assay should provide a nonsurgical means of accurately estimating dogs’ iron stores.
Effect of papain digestion on the specificity of fluorescein-labeled immunoglobulins
Authors: Mengeling William L. , Paul Prem S.
Published: February 2025

During initial studies, we found that many fluorescein isothiocyanate-labeled anti-immunoglobulin conjugates were unstable and tended to aggregate and precipitate when used for indirect immunofluorescence microscopy. In some instances, the precipitate was extensive enough to interfere with interpretation of the test results. Attempts to resolve this problem resulted in a procedure by which such conjugates were digested with papain to Fab and Fc fragments before use. Aggregation and precipitation were prevented, while desired antibody activity was retained. Digestion with papain also reduced the diffuse background fluorescence (commonly referred to as nonspecific fluorescence or staining) that is often associated with conjugates before they are sorbed with tissue powders or chromatographed to remove highly labeled immunoglobulin molecules.
Metabolism of naturally occurring [13C]glucose given orally to horses
Authors: Klein Hans-J. , Schulze Eckhard , Deegen Eckehard , Giese Werner
Published: February 2025

In 5 horses, 13CO2/12CO2 ratios in expired air were determined using isotope mass spectroscopy to investigate metabolism of naturally occurring [13C]glucose. Oral glucose tolerance tests (ogtt) were performed using maize or beet glucose. Maize has a higher 13C concentration than that of most plants.

The 13CO2/12CO2 ratios after ogtt was performed using maize glucose were compared with 13CO2/12CO2 ratios in expired air after ogtt was performed using beet glucose. The ratio also was determined during the period horses were not fed.

Using ogtt, all horses were glucose tolerant. The ogtt performed using beet glucose led to minimal changes in 13CO2/12CO2 ratios. The 13CO2/12CO2 ratios decreased significantly (P < 0.01) when horses were not fed. After oral dosing with maize glucose, 13CO2/12CO2 ratios reached maximal increases 5 hours after dosing and reached baseline values 15 hours after dosing.