bluuebunny/crossref_metadata_2025 huggingface dataset:
Radiographic assessment of epiglottic length and pharyngeal and laryngeal diameters in the Thoroughbred
Authors: Linford Robert L. , O'Brien Timothy R. , Wheat John D. , Meagher Dennis M.
Published: February 2025

SUMMARY AND CONCLUSIONS

A lateral radiograph of the pharyngeal region provides a technique for identifying pharyngeal disorders, including entrapment of the epiglottic cartilage and dorsal displacement of the soft palate. Epiglottic cartilage length, predicted from radiographs by measurement from the body of the thyroid cartilage to the tip of the epiglottis (thyroepiglottic length), was well correlated to actual length at postmortem examination (r2 = 0.98). Thyroepiglottic length, corrected for magnification, was 8.76 ± 0.44 cm in 24 healthy Thoroughbreds. Nine Thoroughbreds with entrapment of the epiglottic cartilage and 6 with dorsal displacement of the soft palate had significantly short thyroepiglottic lengths—6.59 ± 0.33 cm and 6.43 ± 0.40 cm, respectively. The nasopharyngeal diameter of the Thoroughbreds with dorsal displacement of the soft palate was significantly less than the nasopharyngeal diameter of healthy Thoroughbreds. There was no significant difference between healthy and abnormal Thoroughbreds for pharyngoepiglottic, laryngeal, or tracheal measurements as determined from the lateral radiographs.

The head should be placed in a normal resting position to obtain the pharyngeal radiograph. Maximum dorsiflexion of the head significantly increased the pharyngoepiglottic distance, whereas maximum ventriflexion significantly decreased this distance. The nasopharyngeal diameter during dorsiflexion was significantly greater than during ventriflexion.

This investigation documented that a lateral pharyngeal radiograph provides important diagnostic information for evaluating suspected pharyngeal disorders in Thoroughbreds with airway obstruction of the cranial part of the respiratory tract.
Influence of selenium on aflatoxin B1 or crotalaria toxicity in turkey poults
Authors: Burguera John A. , Edds George T. , Osuna Orlando
Published: February 2025

This research compared the toxic effects of aflatoxin B1 and monocrotaline, the active principle of Crotalaria spectabilis, and the additive effect between aflatoxin B1 and monocrotaline in turkey poults. It was of interest whether selenium fed at dosage levels of 0.1, 5, or 10 μg/g of feed would protect against the toxic effect of aflatoxin and/or monocrotaline, and whether the toxicants would result in detectable residues in poult tissues. A total of 180 healthy 1-day-old male turkey poults was assigned at random to 12 treatment groups (15 birds/group).

Body and liver weight losses, and low serum concentrations in total protein (TP), albumin (A), α-globulin (αG), and β-globulin (βG), as well as high values in γ-globulin (γG), were produced in the groups fed crotalaria. Pathologic changes were induced by monocrotaline with no protection afforded by the added selenium. Low values in TP, A, αG, and βG and in body and liver weights were observed in groups given the combination of aflatoxin plus crotalaria. Gross lesions were associated with an additive toxic effect and a lack of protective effect of selenium against this combination.

However, higher values in TP, A, αG, and βG, and liver weights in groups fed aflatoxin B1 plus selenium indicated that selenium had a protective effect against aflatoxin toxicity.

Residues of aflatoxin B1 and aflatoxin M1 were found in the kidneys of poults fed aflatoxin B1; also, dehydro-retronecine (the metabolite of monocrotaline) was detected in livers of poults fed Crotalaria spectabilis seeds.
Absorption and distribution patterns of aflatoxicol and aflatoxins B1 and M1 in blood and milk of cows given aflatoxin B1
Authors: Trucksess Mary W. , Richard John L. , Stoloff Leonard , McDonald John S. , Brumley William C.
Published: February 2025

Two 600-kg lactating cows were each given a single oral dose (0.5 mg/kg of body weight) of aflatoxin B1 (B1). Samples were obtained at postdosing hours 0, 1, 2, 3, 4, 6, 8, 10, and 12 and thereafter every 12 hours for 10 days. Aflatoxicol (Ro), B1, and aflatoxin M1 (M1) were found in the milk, plasma, and rbc of both cows at postdosing hour 1. Maximum concentrations of the toxins were observed at 12 and 60 hours. The ratio of the concentrations for Ro, B1 and M1 was approximately 1:10:100. Both cows had clinical signs of distress at 24 hours; 1 cow died at 60 hours and the other cow recovered within 4 days.

In the samples of liver, kidney, urine, bile, and rumen contents of the cow that died, the B1 concentrations were 5.1, 3.3, 4.1, 1.6, and 320 ng/g, respectively, and the M1 concentrations were 4.3,20, 37,16, and 8.6 ng/g. The Ro concentrations in the kidney were approximately equal to that of B1; however, liver, urine, bile, and rumen contents concentrations were 0.88, 0.10, 0.36, and 4.9 ng/g, respectively.
Effects of T-2 mycotoxin on bovine serum proteins
Authors: Mann D. D. , Buening G. M. , Hook B. , Osweiler G. D.
Published: February 2025

Mycotoxin T-2 (0.5 mg/kg of body weight) was administered orally to mixed-breed beef calves. Serum protein fractions, immunoglobulin (Ig) G, IgM, and several complement protein concentrations were studied in control and toxin-treated calves. Total protein, albumin, and globulin concentrations all decreased in toxin-treated calves as compared with that in controls. Similarly, the concentrations of α-, β1-, and β2-globulin fractions were reduced in the toxin-treated calves more than those in controls.

The IgG and IgM values were lower in toxin-treated calves than those in the controls. Complement proteins Bbov (of the alternate pathway) and the 3rd component of complement were lower in the toxin-treated calves. The fragment of Bbov activation, Bγ2, was increased after toxin treatment, indicating that activation of the alternate complement pathway was responsible for at least some of the reduction of the 3rd component of complement.
Serologic survey for leptospirosis in Arizona beef cattle in 1981
Authors: Songer J. G. , Chilelli C. J. , Marshall M. M. , Noon T. H. , Meyer R.
Published: February 2025

Sera from 1,215 beef cattle in Arizona were evaluated by leptospiral microscopic agglutination test in 1981. Over 25% had agglutinins to ≥ 1 of 5 serovars of Leptospira interrogans used as antigens (canicola, grippotyphosa, hardjo, icterohaemorrhagiae, and pomona) at a titer of ≥ 1:100, and 8.2% had titers of ≥ 1:400 to ≥ 1 serovars. The most common serovar to which reactions were detected was hardjo; agglutinins were detected at titers of ≥ 1:100 in 14.3% and of ≥ 1:400 in 5.5%. Cross reactions were rare at serum dilutions ≥ 1:100 (2%) and extremely rare at ≥ 1:400 (0.7%). Because vaccination with leptospiral bacterins is seldom practiced in Arizona beef cattle, a titer of ≥ 1:100 may be useful in estimating incidence and prevalence of the disease and as an aid to diagnosis of leptospirosis.
Simultaneous cystometry and uroflowmetry (micturition study) for evaluation of the caudal part of the urinary tract in dogs: Studies of the technique
Authors: Moreau Philippe M. , Lees George E. , Gross David R.
Published: February 2025

A procedure similar to one used for urodynamic evaluation of persons was adapted for simultaneous cystometry and uroflowmetry in dogs. Percutaneous transabdominal urinary bladder catheterizations were used for bladder infusion and cystometry, so that urine flow during voiding would not be altered by urethra instrumentation.

The technique was evaluated twice in each of 12 healthy dogs (6 males and 6 females). Studies of individual dogs were performed 1 week apart. Comparisons were made between xylazine and oxymorphone for sedation to accomplish the procedure. Although the 2 drugs provided adequate sedation, oxymorphone was unsatisfactory because it interfered with micturition, whereas xylazine generally did not. Adverse consequences of the procedure occurred infrequently and were minor. According to results of urinalyses, hematuria or pyuria, or both, appeared during the week after the procedure was done in a few dogs, and staphylococcal bacteriuria was induced in 4 dogs. Fluid leakage from urinary bladders was not demonstrated by abdominal paracentesis immediately after each procedure or by contrast radiography performed the day after the 2nd study for each animal.

Micturition studies were concluded to be reasonably safe to do, especially when performed by experienced individuals. The studies were judged to have considerable potential value as a means to evaluate lower urinary tract function in dogs.
Comparative biological features of a rat liver abscess model induced with three Fusobacterium necrophorum strains
Authors: Scanlan C. M. , Berg J. N. , Lairmore M. D.
Published: February 2025

Several biological features were compared in a rat liver abscess model, using intraportal inoculations with 3 bovine strains of Fusobacterium necrophorum which varied in virulence. Serum alanine aminotransferase activities were increased significantly (P < 0.05) in rats inoculated with F necrophorum 2101 by postinoculation hours 6, 12, and 24. Thereafter, alanine aminotransferase values returned to base line for the remainder of the experiment. Also, rats inoculated with F necrophorum 2101 had a significantly greater (P < 0.05) weight loss than did the control rats during the first 5 postinoculation days and developed leukocytosis characterized by a neutrophilia with a left shift. The duration of the bacteremia was related directly to the virulence of the F necrophorum strain. Fusobacterium necrophorum 2101, a biotype A which was the most virulent, induced the most persistent bacteremia; F necrophorum 2035, a biotype B which was the least virulent, produced the shortest bacteremia; and F necrophorum 2030, a biotype AB which was of intermediate virulence, led to bacteremia of intermediate duration. Plasma endotoxin was demonstrated intermittently during the first 24 hours, but did not correlate with the bacteremia.
Mechanism of diphacinone rodenticide toxicosis in the dog and its therapeutic implications
Authors: Mount Michael E. , Feldman Bernard F.
Published: February 2025

Vitamin K1 (5 mg/kg of body weight/day divided for several 5-day regimens) was effective in preventing bleeding diathesis in diphacinone-poisoned dogs. Diphacinone, a vitamin K-inhibiting rodenticide, was given 2.5 mg of diphacinone/kg of body weight orally in divided doses 2 times daily for 3 days. One dog was given 5.0 mg of warfarin/kg in 2 divided doses for 3 days.

Hemograms and biochemical profiles were performed every other day. A pancreatic exocrine function test was performed before and after administration of diphacinone and warfarin. All dogs were monitored, using routine coagulation screening tests and assays of coagulation factors II, VII, IX, and X.

When laboratory results or clinical illness indicated hemorrhage, diphacinone-treated dogs were given 5.0 or 2.5 mg of vitamin K1/kg in divided doses 3 times a day for 5 days. The warfarin-treated dog was given 2.5 mg of vitamin K1/kg of body weight in divided doses 3 times a day for 5 days. Of the diphacinone-treated dogs, 1 dog (given 2.5 mg of vitamin K1/kg) required 3 vitamin K regimens and 2 dogs (given 5.0 mg of vitamin K1/kg) required only 2 vitamin K regimens. The warfarin-treated dog required only 1 vitamin K1 regimen. Bleeding was observed in the diphacinone-treated dogs up to 2 weeks after treatment.

The vitamin K-enzyme complex was inhibited in diphacinone-treated dogs for approximately 30 days, as indicated by routine coagulation screening tests and coagulation factor inhibition. Hepatic dysfunction was not observed. There was a significant reduction (P < 0.001) in pancreatic exocrine function although the final values were within the values established for 24 clinically normal dogs. Amount and duration of vitamin K1 therapy were important aspects of therapy for diphacinone-induced toxicosis in dogs. Therapy effective for warfarin toxicosis was ineffective against diphacinone toxicosis due to inadequate vitamin K dosage and duration of therapy.
Plasma amino acid, glucagon, and insulin concentrations in dogs with nitrosamine-induced hepatic disease
Authors: Strombeck Donald R. , Harrold Doris , Rogers Quinton , Wheeldon Eric , Stern Judith , Schaeffer Monica
Published: February 2025

Plasma amino acids, glucagon, and insulin concentrations were determined once a week in dogs that developed acute hepatic necrosis and chronic hepatic insufficiency after treatment with dimethylnitrosamine. During the acute phase, plasma concentrations of most amino acids increased, with the changes usually correlating with increased glucagon values. Insulin correlated with changes in 10 of 21 amino acids, but the latter were not the most abundant nor the branched-chain amino acids. During the chronic phase, plasma phenylalanine, tyrosine, and methionine concentrations remained increased throughout the study. Plasma values of these amino acids did not correlate with plasma concentrations of either glucagon or insulin. The values of the most abundant amino acids were less than base-line levels during the chronic phase, and 9 of 10 of these correlated positively with glucagon concentrations, but not insulin. Only proline correlated positively with insulin. Isoleucine and valine showed a negative correlation with insulin. The low concentrations of the nonaromatic amino acids increased during the time from the early to late chronic phase, during which time plasma glucagon increased and insulin remained unchanged. This study shows that a significant positive correlation existed between glucagon and the most abundant plasma amino acids during the chronic phase of hepatic insufficiency, at which time most plasma amino acid concentrations were returning toward base line. Increased glucagon values did not correlate with any evidence for deterioration of hepatic function.
Course of feline leukemia virus infection and its detection by enzyme-linked immunosorbent assay and monoclonal antibodies
Authors: Lutz Hans , Pedersen Niels C. , Theilen Gordon H.
Published: February 2025

Monoclonal antibodies specific for 3 distinct epitopes of the species-specific determinants of feline leukemia virus (FeLV) p27 were used in an enzyme-linked immunosorbent assay (elisa) for measurement of serum p27 in cats infected with FeLV. Group-specific antigen (gsa) of FeLV in peripheral blood leukocytes was also determined by an immunofluorescence assay. Antibodies to FeLV and the feline oncornavirus-associated cell membrane antigen (focma) were also measured.

Thirty-six cats were surveyed and assigned to 4 categories. Five developed persistent viremia (category 1), characterized by continuous expression of p27, gsa, and low antibody titers to FeLV and focma. Eleven cats with transient viremia (category 2) and 13 cats that were never detectably viremic (category 3), as judged by absence of gsa and p27, developed increased antibody titers to FeLV and focma. Seven cats were never viremic, as judged by the gsa in the peripheral blood leukocytes, but still had detectable serum p27 (category 4). Most category 4 cats developed high antibody titers against focma and/or FeLV.

Of 307 field cats examined, 7% of the healthy cats and 10% of the sick cats could be assigned to category 4. However, this difference was not significant (P ≥ 0.05). Of 26 cats with neoplasms 2 (1 of 12 with lymphosarcoma) could be classified as category 4. Because virus could be isolated from 2 category 4 cats, they were considered immune carriers.
Granules of blood eosinophils are stained directly by antiimmunoglobulin fluorescein isothiocyanate conjugates
Authors: Floyd Kim , Suter Peter F. , Lutz Hans
Published: February 2025

Direct staining of the granules of blood eosinophils by anti-immunoglobulin fluorescein isothiocyanate (fitc) conjugates was observed when feline blood smears were tested for presence of feline leukemia virus (FeLV) antigen by immunofluorescent antibody. When blood smears of other species including swine, horses, cattle, dogs, sheep, birds, and human beings were examined, direct staining of eosinophils by fitc conjugates was also detected. This fitc staining was restricted to eosinophils and was not observed in neutrophils, lymphocytes, and platelets. Direct fitc staining of eosinophils does not represent a problem in immunofluorescent test for the detection of FeLV infection in cats, as long as the eosinophils, which can easily be recognized as such, are excluded from the spectrum of interpreted cells.
Comparison of Mycoplasma hyopneumoniae strains by serologic methods
Authors: Ro L. H. , Ross R. F.
Published: February 2025

Six field strains of Mycoplasma hyopneumoniae isolated from pneumonic lungs of pigs, reference strains 11 and J of M hyopneumoniae, Ms 42 strain of Mycoplasma flocculare, and BTS 7 strain of Mycoplasma hyorhinis were compared serologically, using hyperimmune antisera produced in rabbits. All strains of M hyopneumoniae were closely related as determined with the disk growth-inhibition test; however, differences in zone sizes indicated that some antigenic heterogeneity existed. Cross-reactions were not detected between M hyopneumoniae, M flocculare, and M hyorhinis with the growth-inhibition test. The metabolic-inhibition test was more useful for detection of intraspecies antigenic difference than was the growth-inhibition test, since antigenic diversity was clearly detected among M hyopneumoniae strains. Slight cross-reactions were observed between M hyopneumoniae and M flocculare. Using 2-dimensional immunoelectrophoresis, antigenic differences were observed among M hyopneumoniae strains, although many common components also were detected in electropherograms. Mycoplasma flocculare possessed a close antigenic relationship to M hyopneumoniae, as determined by two-dimensional immunoelectrophoresis, whereas both organisms were less related to M hyorhinis. Evidence obtained in this study indicated that strains of mycoplasmas tentatively identified as M hyopneumoniae were similar antigenically, but evidence was obtained also of some diversity in antigenic structure among these strains.
Suppressed lymphocyte blastogenic responses and enhanced in vitro growth of infectious bovine rhinotracheitis virus in stressed feeder calves
Authors: Blecha Frank , Minocha Harish C.
Published: February 2025

Hereford steers were stressed on a large-animal treadmill operating at speeds of 1.8 to 2.2 m/s. Blood samples were collected from indwelling jugular catheters before, during, and after exercise. Peripheral blood lymphocytes from stressed calves at 5 and 30 minutes after exercise had less (P < 0.01) mitogen-induced blastogenic responses when compared to pre- or 60-minute postexercise values. Serum from stressed calves incorporated into lymphocyte cultures from nonstressed steers resulted in less (P < 0.01) lymphocyte blastogenic responses. Infectious bovine rhinotracheitis viral growth in bovine kidney cell cultures was enhanced 4-fold when cultured with serum from stressed calves. These data indicate that acute physical exertion may cause physiologic alterations in calves that modulate cellular immunity and viral replication.
Effect of ethionine on hematologic and serum biochemical values in fasted calves
Authors: Boermans Herman J. , Black William D.
Published: February 2025

dl-Ethionine (0.87 g/kg of body weight) was administered iv to 6 fasted (12 hour) Holstein bull calves (4.5 months old). Fasting, which was continued for an additional 48 hours, caused a body weight loss (10.82% to 11.96%), a mild increase in pcv, and an increase in the serum free fatty acids (1.204 mmole/L, fasted; 0.949 mmole/L, fasted ethionine-treated calves). Ethionine caused a decrease in the total plasma proteins from 6.5 g/dl to 5.5 g/dl and total serum lipids from 493.9 mg/dl to 307.8 mg/dl. The decrease in the serum esterified fats included all the lipid fractions (triglycerides, cholesterol, and phospholipids). The The calves’ wbc and serum enzymes aspartate aminotransferase and l-alanine aminotransferase remained within normal range.
Cytoplasmic estrogen receptors in bovine uterus and uterine tube (oviduct)
Authors: Crisman R. O. , McDonald L. E. , Campion D. R. , Rampacek G. B.
Published: February 2025

The effects of progesterone (P) or estradiol benzoate (EB) on unfilled uterine and uterine tubal (oviductal) cytoplasmic estrogen receptors (ER) were studied in nulliparous heifers. Progesterone (4.4 mg/kg of body weight) in oil EB (350 µg) in oil, or oil vehicle only (C) were injected im 24 hours after the end of estrus. The heifers were euthanatized 36 hours later. There was a difference (P < 0.005) in the concentration of ER among treatment groups, but no difference (P > 0.05) between the ER concentrations in the uterus and uterine tube within each treatment group. The affinity constant (KA) of the uterine tubal ER was similar among the treatment groups (P > 0.15), and there was no difference (P > 0.05) in the KA between the uterus and uterine tubal ER within the P and C treatment groups. The KA of the uterine ER of the EB-treated heifers was greater (P < 0.001) than that in either P- or C-treated heifers.
Continuous caudal epidural and subarachnoid anesthesia in mares: A comparative study
Authors: Skarda R. T. , Muir W. W.
Published: February 2025

A new technique for producing continuous caudal epidural analgesia (cea) and caudal subarachnoid analgesia (csa) in adult horses (mares) without causing loss of pelvic limb function is described. A modified 17-gauge Huber-point directional needle was used to place a catheter with stylet into either the epidural or subarachnoid space at the lumbosacral intervertebral junction. The catheter was positioned at either the midsacral (S2-3) subarachnoid space or caudal portion of the sacral (S-3 to S-5) epidural space in 7 mares. The position of the catheter was confirmed radiographically. A 2% solution of mepivacaine HCl was used at an average dose of 0.061 ± 0.013 mg/kg (1.3 ± 0.3 ml) to produce csa and 0.196 ± 0.034 mg/kg (4.1 ± 0.7 ml) to produce cea. Onset of analgesia to superficial and deep muscular pinprick stimulation was faster with csa than it was with cea (8.2 ± 2.4 minutes vs 21.4 ± 3.8 minutes). Maximal caudal analgesia extended from spinal cord segments S-1 to coccyx during csa and cea. Periods of analgesia were shorter with csa than with cea (70.0 ± 21.8 minutes vs 102.1 ± 13.2 minutes). Perineal (S-4 to S-5) dermatome subcutaneous temperature was increased after epidural and subarachnoid injections of mepivacaine HCl solution. Heart rate, respiratory rate, systolic, diastolic, and mean arterial blood pressures, pulse pressure, rectal temperature, arterial blood gas tensions (PaCO2, PaO2), pHa, hematocrit, and total solid concentrations did not change significantly (P > 0.05) from base-line values after injection. The benefits and potential complications of csa and cea in horses are discussed.
Model of chronic pancreatitis in the dog
Authors: Strombeck Donald R. , Wheeldon Eric , Harrold Doris
Published: February 2025

A model of chronic pancreatitis was developed and characterized in the dog. Pancreatitis was produced by infusion of oleic acid through a cannula in the accessory pancreatic duct. Biochemical changes included early and marked increases in serum amylase and lipase activities which returned to base line within 3 weeks, at which time the dogs were clinically normal. In dogs euthanatized within 2 weeks, pathologic changes included massive necrosis and hemorrhage, cystic spaces filled with fluid, and abscesses. Histologic features revealed acute exudative pancreatitis with pancreatic atrophy and fibrosis. In dogs killed between weeks 3 to 12, changes included: marked atrophy with remaining acini surrounded by remnants consisting of collapsed stroma, blood vessels, and pancreatic ducts; marked coarse fibrosis with scattered inflammatory cells and occasional acinar tissue; and large irregular pseudocysts.
Site of 3-methylindole and indole absorption in steers after ruminal administration of l-tryptophan
Authors: Hammond Andrew C. , Glenn Barbara P. , Huntington Gerald B. , Breeze Roger G.
Published: February 2025

To determine the site of 3-methylindole (3MI) and indole absorption in cattle after ruminal administration of l-tryptophan (trp), 4 Holstein steers were given 0.4 g of trp/kg of body weight directly into the rumen through ruminal cannulas. Chromium EDTA and ruthenium phenanthroline were added to feedings of orchard grass hay twice a day for measurement of fluid and particulate flow to the duodenum, respectively. Passage of 3MI and indole (products of ruminal fermentation of trp) to the duodenum was determined by the products of digesta flow rate and concentration in duodenal contents. Ruminal fluid, duodenal contents, and jugular blood were sampled at postdosing hours (pdh) 0, 6, 12, 18, 24, 36, and 72 for analysis of 3MI, indole, and digesta flow markers.

Ruminal, duodenal, and jugular plasma concentrations of 3MI and indole peaked at pdh 12 to 24 at 152.4 and 25.9; 15.5 and 1.0; and 8.7 and 2.2 mg/L, respectively. Most 3MI and indole reaching the duodenum were associated with the particulate phase of the digesta. On a molar basis, total passage of 3MI to the duodenum during 72 hours amounted to 1.0% of the trp dose for 3MI and 0.1% of the trp dose for indole. Absorption of 3MI and indole in these steers was almost entirely proximal to the duodenum.
Measurement of plasma antithrombin III activity in healthy horses
Authors: Stephens Kay A. , Morcom Ellen , Hood David M.
Published: February 2025

A fluorometric assay was used to determine plasma antithrombin III (AT III) activities in 15 healthy adult horses. Nearly all plasma samples had an initial value of greater than 100% thrombin inhibited, so a 1:1 dilution of the prepared samples was performed. Following dilution, the mean value of the animals was 59.17 ± 7.4% thrombin inhibited. Mares had significantly greater AT III activity than did geldings (P < 0.01). The results of this study indicate the horse has more AT III activity than did other domestic species in which AT III activity has been reported.
Equine colonic motility: Interactions among wall motion, propulsion, and fluid flow
Authors: Sellers Alvin F. , Lowe John E. , Rendano Victor T.
Published: February 2025

Transmission of intestinal content with respect to wall position and intraluminal pressure was studied using implanted catheters in portions of the haustrated left ventral colon and nonhaustrated pelvic flexure and left dorsal colon in 3 conscious, standing, and feeding ponies. Wall position and content movement was studied in 1 noncatheterized conscious pony that was standing and eating. When coordinated wall movements involving ≥ 30 cm of adjacent colon were seen, point-to-point content movement accompanied intraluminal pressure peaks occurring in the same direction. Near the pelvic flexure, intraluminal pressure peak maximums coincided with reduced colonic diameters and reduced intercatheter distances. Qualitative observation of 3 related aspects of intestinal motility: wall motion, propulsion, and fluid movement can be studied in the conscious feeding pony.
Characteristics of the herpesvirus of malignant catarrhal fever isolated from captive wildebeest calves
Authors: Castro A. E. , Ramsay E. C. , Dotson J. F. , Schramke M. L. , Kocan A. A. , Whitenack D. L.
Published: February 2025

A herpesvirus was isolated from buffy coat cells from a newborn wildebeest (Connochaetes gnou) and from tissues of a 12-day-old wildebeest during the 1982 calving season of a captive, inbred herd maintained in a zoologic collection. Both wildebeests were clinically healthy, and there was no herd record that malignant catarrhal fever (mcf) existed. Each viral isolate produced cytopathologic changes in bovine kidney cell cultures (intranuclear inclusions and massive syncytia). The viral-infected cell cultures contained antigens of mcf virus detected by immunofluorescence. The morphology of each viral isolate as determined by electron microscopy was that of a herpesvirus. Suspensions of 4 to 5 ml of disrupted cell culture material which contained virus from each wildebeest were inoculated (iv) into white-tailed deer (Odocoileus virginianus). Each deer became clinically ill within 28 days. Both deer had mucoid catarrh and a febrile response (40.5 to 41 C). Each also seroconverted to mcf virus. The histopathologic change in the tissues from the 2 inoculated deer was vasculitis. At 16 to 17 days after the deer were inoculated, a syncytial-forming virus was isolated from each deer from buffy coat cells fused with polyethylene glycol (1000) to bovine fetal kidney cells. The virus was identified as mcf virus by immunofluorescence and production of antibody to mcf virus. The presence of virus in the inbred wildebeest herd established this species as a reservoir or latent carrier of African mcf virus at the zoologic park.
Effect on outcome of intramammary challenge exposure with Staphylococcus aureus of somatic cell concentration and presence of an intramammary device
Authors: Schultze W. Donald , Paape Max J.
Published: February 2025

Results of experimental Staphylococcus aureus intramammary challenge of all quarters of 6 cows, each fitted with an intramammary device (imd) in 2 quarters, and of 10 quarters of 3 cows not fitted with an imd were reported. Infection was established in all 34 quarters, regardless of presence or absence of an imd. Neither the course nor severity of early S aureus intramammary infection were influenced by the presence of an imd or by differences in milk somatic cell (msc) concentration in the gland at the time of bacterial challenge infusion, up to a msc concentration of nearly 1 million/ml. Cumulative success of experimental infection in this and a previous study from our laboratory was nearly 100% in glands in which the msc concentration was < 1 million/ml and about 17% when the msc concentration exceeded 1 million/ml.
Radiographic and gross anatomy of the nasolacrimal duct of the horse
Authors: Latimer C. A. , Wyman M. , Diesem C. D. , Burt J. K.
Published: February 2025

The anatomy of the nasolacrimal duct of the horse was studied grossly and radiographically, using barium contrast dacryocystorhinography and methyl methacrylate casts. Radiographic contrast studies were performed on 4 specimens and gross dissections were performed on 6 specimens. Dacryocystorhinography accurately delineated the course of the nasolacrimal duct, as was subsequently demonstrated by gross dissection. A 60% barium sulfate suspension produced good radiographic contrast, allowing critical assessment of the anatomic features of the nasolacrimal duct.
Porcine regional brain and myocardial blood flows during halothane-O2 and halothane-nitrous oxide anesthesia: Comparisons with equipotent isoflurane anesthesia
Authors: Manohar Murli , Parks Christine
Published: February 2025

Regional distribution of brain and myocardial blood flow were examined in 9 instrumented isocapnic normothermic swine, using 15-μm diameter radionuclide-labeled microspheres injected into the left atrium. Minimal alveolar concentration (mac) of halothane required to prevent gross purposeful movement in response to a noxious stimulus in 50% of the pigs was found to be 0.70%. Measurements were made on each animal during nonanesthetized state (control), 1.0 and 1.5 mac halothane anesthesia, and the equivalent of 1.0 and 1.5 mac halothane anesthesia, using 50% N2O. The order of anesthetized steps was randomized for each pig. Recovery periods of 60 minutes were interposed between the anesthetic treatments. During halothane + 50% N2O anesthesia, heart rate, cardiac output, mean aortic pressure, and rate-pressure product were higher than comparable levels of halothane-O2 anesthesia. Halothane caused dose-dependent vasodilatation in all regions of the brain. Cerebral, cerebellar, and brain-stem blood flows at 1.5 mac halothane were 135%, 135%, and 115% of respective control values. Substitution of 50% N2O to maintain same mac dose markedly exaggerated the increment in porcine cerebral and brainstem blood flows, especially at 1.0 mac when perfusions in these regions were 204% and 128% of respective control values. At 1.5 mac anesthesia produced by halothane + 50% N2O, the cerebral, cerebellar, and brain stem perfusions were 153%, 146%, and 129% of control values.

Transmural myocardial blood flow decreased from control value with both levels of halothane anesthesia, but with equivalent mac anesthesia produced by halothane + 50% N2O, myocardial perfusion remained near awake values. Subendocardial:subepicardial perfusion ratio remained unchanged from control value throughout the study, indicating that O2 delivery in the inner layers probably kept pace with O2 demand. It is concluded that substitution of 50% N2O for halothane to maintain equipotent anesthesia resulted in a marked increase in regional brain blood flow while myocardial perfusion was maintained near awake values.
Pulmonary and hematologic changes in swine with Mycoplasma hyopneumoniae pneumonia
Authors: Intraraksa Yanyong , Engen Richard L. , Switzer William P.
Published: February 2025

Studies were made of the physiologic changes in the lung of young growing pigs intratracheally inoculated at 5.5 to 6 weeks of age with Mycoplasma hyopneumoniae. Hematologic changes also were studied. Studies were performed at the 4th, 5th, and 6th weeks after inoculations were done.

The inoculated pigs had a marked decrease in body weight gain. There were no significant changes in the heart rate, respiratory rate, and rectal temperature, even though at necropsy the apical, cardiac, and diaphragmatic lobes of the lungs of inoculated pigs had scattered, but well-demarcated, pneumonic lesions. The lungs were edematous and increased in weight, compared with those of control (noninoculated) pigs.

There were several changes in respiratory functions in the inoculated animals, including significant increases in esophageal pressure negativity, expiratory flow rate, tidal and minute volumes, and work of breathing and significantly less oxygen consumption. Inspiratory flow rate and airway resistance were markedly increased. The elasticity of infected lungs was reduced, as shown by notable decreases of dynamic lung compliance.

According to blood gas analyses, acid-base balance had changed in the inoculated pigs. Arterial blood pH, arterial partial pressures of O2 and CO2, and arterial concentration of HCO3− decreased. To some degree respiratory acidosis indicated by a significant decrease of base excess was evident in the blood of inoculated pigs. As a result, inoculated animals required hyperventilation (compensatory respiratory alkalosis) to maintain the pH of arterial blood near a physiologically normal value.

The pigs with mycoplasmal pneumonia showed no drastic hematologic changes. There were no apparent changes observed in rbc number, pcv, or hemoglobin concentration; the total number of wbc increased, however. The differential count revealed large increases in the number of neutrophils, small increases in number of monocytes, eosinophils, and basophils, and slight decreases in numbers of lymphocytes.
Rabbit small intestinal β-galactosidases
Authors: Toofanian F.
Published: February 2025

The β-galactosidase activities of the rabbit small intestinal mucosa were studied over the pH range of 2.6 to 8.4, using different substrates, and in the presence or absence of the enzyme inhibitor p-chloromercuribenzoic acid. The results indicated the presence of 4 β-galactosidases: (i) a neutral β-galactosidase (lactase) with optimum pH of 5.8, (ii) an acid β-galactosidase I with optimum pH of 3.4, (iii) an acid β-galactosidase II with optimum pH of 4.6, and (iv) a hetero β-galactosidase with pH optimum of 7.6. Seemingly, 3 of these β-galactosidases were comparable with those in other mammals, and the 4th has not been reported in other species.
Toxicity of seeds of three Aesculus spp to chicks and hamsters
Authors: Williams M. C. , Olsen J. D.
Published: February 2025

Seeds of horse chestnut (Aesculus hippocastanum), Ohio buckeye (A glabra), and yellow buckeye (A octandra) were tested for toxicity to 2-week-old Leghorn chicks and adult female Syrian hamsters. The ld50 of the water soluble portion of alcoholic extracts of horse-chestnut seeds (for hamsters and chicks) and of dried, powdered seeds (chicks only) was determined.

The ld50 for a single dose of extract from horse-chestnut seeds was 10.6 mg/g of body weight for chicks and 10.7 mg/g of body weight for hamsters. The ld50 for chicks given 2 consecutive daily doses of horse-chestnut seed was 6.5 mg/g. Toxic signs included depression, muscular incoordination, paralysis, coma, and death. Extracts of seeds of Ohio buckeye were nontoxic to chicks and hamsters when fed at 80 mg/g. One of 5 hamsters died after dosing for 5 days with 80 mg/g of extract of seeds of yellow buckeye/g.
Dose response of topical carbamylcholine chloride (carbachol) in normotensive and early glaucomatous Beagles
Authors: Gelatt Kirk N. , Gum Glenwood G. , Wolf E. Daniel , White Marilyn M.
Published: February 2025

Single-dose loading with a placebo (0.5% methylcellulose) and 0.75%, 1.5%, 2.25%, or 3% carbamylcholine chloride (carbachol) was evaluated in normotensive and glaucomatous Beagles to determine dose response. The 4 carbachol concentrations significantly (P < 0.05) lowered intraocular pressure and reduced pupil size in the normotensive and early glaucomatous Beagles at most time intervals as compared with baseline values, nontreated fellow eyes, and placebo-treated eyes. There were no significant (P < 0.24) effects on intraocular pressure or pupil size by unilateral carbachol instillations as compared with base-line values or placebo-treated eyes.
Role of prostaglandins in pathogenesis of bovine mastitis induced by Escherichia coli endotoxin
Authors: Giri S. N. , Chen Z. , Carroll E. J. , Mueller R. , Schiedt M. J. , Panico L.
Published: February 2025

Four doses (5 to 100 μg, 1 dose/quarter) of Escherichia coli endotoxin were introduced into lactating mammary glands of 2 cows. There was no effect on milk prostaglandin (pg) E2 concentration, except that the concentration was increased from 200 pg/ml of milk to 1,060 pg/ml at post-treatment hour (pth) 8 in cow 1 and from 75 to 420 pg/ml at pth 4 in cow 2 after the highest dose 100 μg. Endotoxin caused a dose-dependent increase in milk pgf2α concentrations in both cows.

After the highest dose, pgf2α was maximally increased from 200 to 3,500 pg/ml at pth 4 in cow 1 and from 250 to 2,000 pg/ml in cow 2 at pth 8. The instillation of 50 μg of endotoxin in all 8 quarters of 2 more lactating cows caused no significant (P > 0.05) changes in milk pge2 and thromboxane B2 concentrations, whereas milk pgf2α was significantly increased from the base-line value of 642 to 2,683, 1,189, and 2,281 pg/ml at pth 4, 8, and 12, respectively. The 6-keto-pgf1α was also significantly increased from the base-line value of 305 to 871, 631, and 600 pg/ml at the corresponding times, respectively. A marked increase in vascular permeability, as judged by high concentrations of serum albumin in the whey, was observed as early as pth 4 and peaked at pth 12 followed by a gradual decline, although it remained significantly increased over the control for 48 hours after treatment.

Somatic cell counts in milk gradually increased and peaked at pth 12 followed by a precipitous decrease at pth 24. However, cell counts remained significantly increased over the control for 60 hours. Seemingly, metabolites of arachidonic acid might be involved in endotoxin-induced mastitis.
Natural and experimental bovine intramammary infection with Prototheca zopfii
Authors: McDonald J. S. , Richard J. L. , Cheville N. F.
Published: February 2025

A naturally occurring case of chronic mastitis caused by Prototheca zopfii was detected in a dairy cow. The cow was observed for 12 weeks, and milk samples were cultured each week. Milk production was decreased, and high numbers (> 103/ml) of the organism were detected in the milk.

Six glands of 2 cows were inoculated with small numbers of P zopfii. All 3 cows were euthanatized, and at postmortem, a progressive pyogranulomatous inflammation was observed in all infected mammary glands. The organism was recovered from tissue and secretions from all inoculated glands and from lymph nodes draining these glands but not from other tissues.
Histologic examination of selected areas of canine pulmonary arteries
Authors: Keith James C. , Rawlings Clarence A. , Schaub Robert G.
Published: February 2025

Selected areas of pulmonary arteries from 18 healthy mixed-breed dogs were examined using histologic staining techniques. Smooth muscle cell, collagen, and elastin content of the tunica intima and tunica media were assessed. Fifteen dogs had abnormalities of tunica intima or tunica media in at least one arterial section examined. Of all arterial sections examined, 40% had histologic changes of the tunica intima or tunica media, and 42% of these vascular lesions were in the main pulmonary artery. The most commonly occurring pathologic change was loss of smooth muscle cells and elastin of the tunica media and replacement by collagen. This lesion is similar to cystic medionecrosis of the aorta. Seemingly, a high frequency of spontaneous vascular lesions exist in pulmonary arteries of young dogs.
Postnatal development of renal tubular amino acid reabsorption in canine pups
Authors: Bovee Kenneth C. , Jezyk Peter F. , Segal Stanton C.
Published: February 2025

The renal clearance of amino acids in canine pups 5 days and 3, 8, and 12 weeks of age was studied. The 5-day-old pups had incomplete reabsorption of most amino acids. At 3 weeks, fractional reabsorption of 16 of 21 amino acids was complete; between 3 and 8 weeks, an adult pattern of reabsorption was present. Seemingly, a rapid development of amino acid transport precedes anatomic development or functional maturation of other transport systems.
Serum concentration of penicillin in the horse after repeated intramuscular injections of procaine penicillin G alone or in combination with benzathine penicillin and/or phenylbutazone
Authors: Sullins Kenneth E. , Messer Nat T. , Nelson Larry
Published: February 2025

Twenty-one adult horses were randomly assigned into 7 groups of 3 and were treated for 5 days with procaine penicillin G, benzathine penicillin, or phenylbutazone in various combinations and dosage schedules. Serum concentration of penicillin was measured serially over a 7-day period. The highest mean peak serum concentration was 2.06 μg/ml. Comparable peak values were seen 2 to 4 hours after administration of 22,000 IU of procaine penicillin G/kg of body weight given once or twice daily. A minimum serum concentration of 0.25 μg/ml was selected as adequate for efficacy against organisms that can be considered sensitive to penicillin. Once daily administration of procaine penicillin G and, although peak concentrations were lower, some regimens of procaine and benzathine penicillin G did maintain this concentration. Concurrent phenylbutazone administration did not affect serum concentration of penicillin appreciably.
Efficacy of ivermectin against Dirofilaria immitis microfilariae in naturally infected dogs
Authors: Suderman M. T. , Craig T. M.
Published: February 2025

Ivermectin, given in a single subcutaneous dose of 200 μg/kg, was evaluated for its efficacy against Dirofilaria immitis microfilariae in a trial with naturally infected dogs. Sodium thiacetarsamide (2.2 mg/kg) was administered twice daily for 2 days to 2 groups of 10 dogs. Two weeks later, 1 group was treated with ivermectin, and the other group was given the vehicle. Microfilariae were not detected (by blood sample concentration techniques) in 90% of the dogs 21 days after they were treated with ivermectin. Microfilariae were not detected in samples of any dog at days 28 and 35. However, 1 dog (not the one positive at day 21) had a detectable microfilaria at day 42. One dog with pretreatment ascites, exercise-induced cough, and high microfilaremial count was anorectic and depressed 2 days after treatment with ivermectin; the clinical signs were resolved 4 days later.
Efficacy of clorsulon for treatment of mature naturally acquired and 8-week-old experimentally induced Fasciola hepatica infections in cattle
Authors: Malone J. B. , Ramsey R. T. , Loyacano A. F.
Published: February 2025

In a dose-titration study against experimentally induced 8-week-old Fasciola hepatica infection (study A), 20 calves were allotted to 5 groups, each of 4 calves, and treated with different doses of an injectable formulation of clorsulon or its vehicle: group 1—controls, no drug; group 2—2 mg of clorsulon/kg; group 3—4 mg of drug/kg; group 4—8 mg/kg; and group 5—16 mg/kg. Mean numbers of flukes recovered from 4 calves in each treatment group were as follows: group 1—112.2, group 2—42, group 3—4.8, group 4—3.0, and group 5—0.2. Percentages of fluke reductions for groups 2, 3, 4, and 5 (clorsulon-treated) calves were 62.6%, 95.7%, 97.3%, and 99.8%, respectively.

Against naturally acquired mature (> 14-week-old) F hepatica infections (study B), a total of 161 flukes were recovered from 7 vehicle-treated control calves (group 6; mean fluke recovery = 23) and no flukes were recovered from 9 calves (group 7) given orally a formulation containing 7 mg of clorsulon/kg of body weight. Eggs were not found in the feces of clorsulon-treated calves at 20 to 21 days after treatment as compared with a mean of 7.4 eggs per gram (epg) in group 6 (control) calves. Mean bile egg recoveries were 13,532 (456 to 66,861) from group 6 calves as compared to recovery of a total of 162 (0 to 160) eggs from 3 of the 9 treated calves.

In a field study (study C) on a herd of 153 cattle naturally infected with F hepatica, 4 of every 5 animals were given an oral formulation of clorsulon (7 mg/kg) and 1 of every 5 animals served as vehicle-medicated controls. For each replicate of 5 animals, 3 were screened for F hepatica infection (2 clorsulon-treated, 1 control) by fecal examination for presence of F hepatica eggs. Mean fecal epg counts on the day of treatment were 6.3 (96.6% prevalence) for 59 clorsulon-treated cattle (group 9) examined and 4.0 (92.9% prevalence) for 28 control cattle (group8). Posttreatment fecal epg counts 26 to 27 days later revealed no F hepatica eggs in 55 clorsulon-treated cattle and 6.9 epg (93.3% prevalence) in 30 control cattle. Follow-up epg counts on 25 fecal samples from treated cattle between January and July 1, 1983 revealed sustained negative epg counts until April 1983. Low numbers of eggs typical of Paramphistomum spp were found in treated and control cattle in both pretreatment and posttreatment fecal samples.
Animal studies of potential chronic lung disease of workers in swine confinement buildings
Authors: Donham Kelley J. , Leininger Joel R.
Published: February 2025

The pathologic changes in laboratory animals housed in a swine confinement building were studied to predict potential chronic health effects on persons working in these buildings. Rabbits and guinea pigs were maintained for 12 months either in a confined nursery-grower unit (test animals) or in conventional laboratory animal housing (controls). Necropsies and histopathologic examinations were performed on animals that died prematurely or were killed at termination of the study. Blood serum from the animals was examined for antibodies to extracts from swine confinement house dust. The confinement atmosphere was monitored for environmental pollutants.

Concentrations of gases and dust in the air of the confinement building were comparable to those found in a typical swine confinement building.

Pulmonic lesions seen in the test rabbits and guinea pigs included diffuse interstitial histiocytic pneumonia. Tracheal and nasal turbinate lesions included epithelial hyperplasia and metaplasia, with submucosal infiltration of plasma cells and heterophils.

Blood from the test animals contained serum precipitins to dust extract from confinement houses. The presence of precipitins combined with the microscopic appearance of the lungs indicated that an immunologic process, such as hypersensitivity pneumonitis, may be used to explain the basis of the observed lung lesions. The tracheal and turbinate lesions are best explained as a reaction to a chronic low-grade irritation.