bluuebunny/crossref_metadata_2025 huggingface dataset:
Detection of La Crosse (California encephalitis) virus antigen in mouse skin samples
Authors: Beaty B. J. , Hildreth S. W. , Blenden D. C. , Casals J.
Published: February 2025

La Crosse (lac) viral antigen was detected in the skin of inoculated mice. Antigen was detected principally in the dermis of 102 of 120 (85%) mice with clinical signs of illness. To demonstrate the specificity of the fluorescence, lac virus was isolated from selected samples and was identified by the complement-fixation test. Antigen was most often detected in skin rich in vascular and nerve tissue and was probably disseminated by hematogenous spread. Antigen was found in muscle, vascular, nervous, and other tissues of the dermis, depending on the age of the mice. Antigen was first detected in the skin of 80% of the mice (5 to 6 days of age) on postinoculation day (pid) 3. On pid 4,100% of these mice were positive, but on pid 5, only 40% were positive, indicating that clearance or neutralization of antigen had occurred in peripheral areas.

The skin biopsy technique may be applicable to diagnosis of arboviral infections in other vertebrates.
Comparison of a direct radioimmunoassay with virus isolation in cell culture for detection of pseudorabies virus in tissues of infected swine
Authors: Neill J. D. , Kelling C. L. , Rhodes M. B.
Published: February 2025

A direct radioimmunoassay (dria) was developed for detection of pseudorabies virus (prv) in tissues of pigs with clinical disease. Homogenates of tissues prepared from 289 swine were tested for prv with the dria and virus-isolation technique (vit). The virus was detected in 53 (18%) of the homogenates by both dria and vit. Fifteen (5%) others were positive for prv by vit, but negative by dria. There were no samples negative by vit and positive by dria. A total of 221 (77%) pigs with clinical prv infection were negative in both dria and vit. Although the vit is more sensitive than dria, the dria possesses certain advantages which include reduced requirement for aseptic procedures and cell cultures, rapidity, and increased objectivity. Moreover, high levels of confidence could be attributed to dria-positive results, since dria-positive/vit-negative results were not obtained.
Evaluation of an ultrasonic amplitude depth analysis technique for pregnancy diagnosis in the cow
Authors: Archibong A. E. , Diehl J. R.
Published: February 2025

Beef and dairy cows (n = 1,053) were tested for pregnancy on 7 farms by ultrasonic scanning. Accuracy was verified by comparison with rectal palpation. Rectal palpation was done 40 to 75 days after breeding and was considered 100% accurate for comparison purposes.

Although diagnostic accuracy of the ultrasonic scanning technique was less than 100%, a confidence interval no larger than 2.3% indicated a high degree of precision for pregnant cows. The confidence interval in the nonpregnant category ranged from 9.2% to 11.8%, which was small in relation to the variation in ultrasonic scanning accuracy. However, considering the large number of cows and the experimental bias that was purposely introduced, the lower accuracy of the ultrasonic method was not unexpected. Cystic ovaries, partially involuted uteri, metritis, and high milk production prevalent at one location accounted for much of the variation observed and lowered the overall accuracy for all cows tested.

The ultrasonic analyzer has potential in testing cows for pregnancy; however, technical improvements in machine configuration must be made and additional testing in controlled experiments and field trials must be conducted before an accurate analysis of this method can be made. At the present state of development, ultrasonic amplitude depth analysis cannot replace rectal palpation for diagnosis of pregnancy in cattle.
Plasma zinc and iron concentrations as measurements for evaluating the influence of endotoxin-neutralizing agents in Escherichia coli endotoxin-induced mastitis
Authors: Verheijden J. H. M. , van Miert A. S. J. P. A. M. , Schotman A. J. H. , van Duin C. T. M.
Published: February 2025

The influence of bacterial lipopolysaccharides on plasma Zn and Fe concentrations and the endotoxinneutralizing capacity of polymyxin B was studied in 3 dairy cows. Also, the feasibility of using plasma Zn and Fe concentrations as measurements for evaluating the influence of endotoxinneutralizing agents in Escherichia coli endotoxin-induced mastitis was studied. A positive relationship was ascertained between the dose of endotoxin given intramammarily (imm) and the effect on mean values of plasma Zn and Fe concentrations.

Seemingly, imm administration of polymyxin B-sulfate before the imm administration of E coli endotoxin partially blocked the effects of endotoxin, as shown by decreases in plasma Zn and Fe.
Purification and partial characterization of a macrophage cytotoxin from Pasteurella haemolytica
Authors: Himmel M. E. , Yates M. D. , Lauerman L. H. , Squire P. G.
Published: February 2025

A protein from Pasteurella haemolytiea that was highly immunogenic and toxic toward bovine alveolar macrophages was partially purified. When isolated from culture supernatants of P haemolytiea serotype 1 or serotype 6, the protein reacted on Ouchterlony immunodiffusion tests with antisera from 12 serotypes of P haemolytiea, but did not cross-react with antisera to serotypes of P multocida. This indicated that the protein may be specific for P haemolytica.

Bacteria were grown in dialysis culture in a brain-heart infusion and calf-serum growth medium. The protein was isolated from the medium by ultrafiltration and size-exclusion chromatography and has a molecular weight of approximately 150,000 daltons. The protein, which is highly immunogenic and has the characteristics of a virulence factor, is common to all serotypes of P haemolytiea, and may be an effective agent for immunization against P haemolytica in cattle.
Ostertagia ostertagi in calves: Clinical parasitism and resistance
Authors: Herlich H.
Published: February 2025

Calves in groups of 3 were orally inoculated with 105, 3 × 105, 5 × 105, 7 × 105, and 9 × 105 Ostertagia ostertagi infective larvae. Two calves inoculated with the highest dosage died in the 3rd week. All survivors and a group of noninoculated controls were challenge exposed with 150,000 O ostertagi L3 on day 47 (or 5 days after initial infections were chemically terminated). There was no evidence that any inoculation dosage had provided protection of the calves against the challenge inoculation.
Controlled test of the efficacy of a feed premix formulation of crufomate on the parasites of the gastrointestinal tract and lungs of dairy calves
Authors: Lyons E. T. , Tolliver S. C. , Drudge J. H.
Published: February 2025

Activity of a feed premix formulation (M-1839) of crufomate against helminths of the gastrointestinal tract and lungs of cattle was determined in a controlled test. Eight calves were treated and 7 were nontreated. The dosage rate of crufomate was 17 mg of active drug/kg of body weight daily for 3 consecutive days.

Removal activity was high against mature Cooperia oncophora (99%) and C punctata (96%) and immature Cooperia spp (87%). Removal of mature Ostertagia ostertagi was 68%. The removal of Strongyloides papillosus and Bunostomum phlebotomum was 72% and 67%, respectively, but only a few specimens were present in the nontreated calves. Efficacies against the other mature and immature species of nematodes ranged from 0% to 34%. Lungworms (Dictyocaulus viviparus) were not effectively removed.
Demonstration of rotavirus antigen in trypsin-digested paraffin tissue sections by immunofluorescence
Authors: Palmer Dieter G. , Pohlenz Joachim F. L. , Weilenmann Roseline P.
Published: February 2025

Trypsin-digested paraffin tissue sections were used to demonstrate rotavirus particles in small intestinal epithelial cells of diarrheic neonatal calves, using direct fluorescent-antibody assay. The results were compared with other techniques to demonstrate rotavirus particles in tissue sections by immunofluorescence. Enzyme treatment of deparaffinized tissue sections gave excellent results with distinct specific fluorescence and minimal background. Prior staining of the tissue section with Mayer’s hematoxylin made simultaneous observation of the same tissue section by light and ultraviolet microscopies possible.
Parafilaria bovicola (Tubangui 1934) in cattle: Epizootiology—Disease occurrence
Authors: Bech-Nielsen Steen , Sjogren Urban , Lundquist Hans
Published: February 2025

Parafilaria bovicola, a filariid nematode affecting cattle, was first identified in Sweden in 1978. The parasite (female, 5 to 6 cm long, 500 μm wide; male, half that size) is associated with lesions caused when the worm is moving subcutaneously and im, giving rise to condemnation losses of approximately 6 kg of meat in an affected animal at slaughter.

Several hypotheses were tested in a questionnaire survey among cattle owners in the enzootic area of the disease, attempting to investigate factors associated with its occurrence in Sweden: (i) Condemnation losses due to P bovicola were overrepresented among animals that came from herds held on pasture the previous year, as opposed to animals from farms with indoor cattle management only, indicating that infection of cattle occurs while they are on pasture, (ii) A statistically significant difference was found between affected and nonaffected herds with respect to age groups, with most cattle affected belonging to the 1- to 2-year age group. And (iii), frequency of Parafilaria-induced lesions showed a seasonal trend, increasing sharply in late December, remaining at about 30% of the slaughter population until July, at which time it dropped to insignificant levels. Seemingly delaying the time of slaughter of animals until the 2nd half of the year may ensure time for lesions to heal and lessen economic losses due to condemnations.
Comparison of the enzyme-linked immunosorbent assay with an early polykaryocytosis inhibition assay and the agar-gel immunodiffusion test for the detection of antibodies to bovine leukemia virus
Authors: Graves Don C. , McQuade Matt , Weibel Kevin
Published: February 2025

An indirect enzyme-linked immunosorbent assay (elisa) was developed, using as test antigen a bovine leukemia virus (blv) glycoprotein complex (94,000 daltons). The specificity of the elisa was determined by using specific bovine reference sera. There was a positive reaction using reference sera containing antibodies to blv, but a negative reaction to reference sera containing antibodies to other ubiquitous bovine agents, ie, bovine viral diarrhea virus (bvdv), foamy-like syncytia virus (bsv), and bovine maedi-like (R-29) virus. The sensitivity of the elisa for detection of antibodies to blv was compared with that of the early polykaryocytosis inhibition assay (epia), which is based on inhibition of blv-induced early syncytia formation in cell culture, and with the agar-gel immunodiffusion (agid) test, using the major glycoprotein (gp51) as antigen. The sera that were tested came from cattle in a high occurrence leukemia herd, cattle in a commercial dairy herd, and from blood samples, obtained from cattle from various parts of Oklahoma, submitted to a diagnostic laboratory for diagnosis of blv infection.

There was 96.2% agreement in the results of all sera tested using the 3 serotests. The greatest number of positive sera (153) were detected by the epia, followed by the elisa (148) and agid test (148). There was disagreement in the test results of only 16 sera. Of the 200 sera tested from the commercial dairy herd, 61 (30.5%) were positive by the elisa, 60 (30%) by the epia, and 57 (28.5%) by the agid test. In the 111 sera from the diagnostic laboratory, 45 (40.5%) were positive by the elisa, 45 (40.5%) by the epia, and 47 (42.3%) by the agid test. With the 102 sera from the high occurrence leukemia herd, 42 (41.2%) were positive by the elisa, 48 (47%) by the epia, and 44 (43.1%) by the agid test.

The indirect elisa is another serotest that can be used for the diagnosis of blv infection in cattle. It is specific, equally as sensitive as the agid test, rapid to perform requiring inexpensive equipment, and may be the preferred serotest for screening large numbers of animals for blv infection.
Trypsin-enhanced replication of neonatal calf diarrhea coronavirus in bovine embryonic lung cells
Authors: Toth Thomas E.
Published: February 2025

Bovine embryonic lung (bel) cells, grown in 8-chamber cell-culture slides, were inoculated with 2.5, 25, and 250 tcid50 of neonatal calf diarrhea coronavirus (ncdcv)/chamber. The ncdcv inocula were prepared in serum-free, trypsin-free regular medium (rm), and in serum-free medium containing 1 μg (TM1), 5 μg (TM5), and 10 μg (TM10) of trypsin/ml; the cells were maintained under identical media. Cytopathic effect (cpe), hemadsorption of rat rbc, formation of syncytia, appearance of immunofluorescing cells, and release of infectious virus was followed from postinoculation hours 4 to 100.

Maintaining the bel cells in medium containing trypsin up to 10 μg/ml did not affect them adversely. The bel cells appeared resistant to infection with ncdcv in rm by cpe, syncytia, immunofluorescing cells, or infectious virus-release parameters. In TM1, TM5, and TM10, all parameters were positive for ncdcv replication. They manifested and developed in positive correlation with increasing trypsin concentration from 1 μg to 10 μg/ml. Release of infectious virions preceded all other parameters of virus replication. Replication of ncdcv was demonstrated earlier by hemadsorption and immunofluorescing cells than by syncytia or cpe. The TM5 and TM10 increased the susceptibility of bel cells to ncdcv by more than a millionfold, as measured by the titer of released virus in these media (> 106 tcid50/ml) as compared with those in rm (infectious virus not demonstrated).
Influence of β-adrenergic antagonism on the response of bovine neonatal lungs to intravenous histamine
Authors: Kotlikoff M. I. , Slocombe R. F. , Robinson N. E.
Published: February 2025

The effects of iv histamine infusion and β-adrenergic blockade on pulmonary function were studied in neonatal Holstein calves. β-Adrenergic blockade with iv propranolol increased total pulmonary resistance, but was without effect on lung compliance, lung volumes, and gas exchange. β-Adrenergic blockade enhanced the histamine-induced increase in total pulmonary resistance and the decrease in dynamic and quasistatic compliance, lung volumes, and arterial oxygen tension. These data indicate that β-adrenergic receptors may be present in the large and small airways of cattle and they modulate the effects of bronchoconstrictor agents as in other species.
Quantitative ultrastructural anatomy of esophagus in different regions in the horse: Effects of alternate methods of tissue processing
Authors: Slocombe Ronald F. , Todhunter Rory J. , Stick John A.
Published: February 2025

A qualitative and quantitative study was made of 2 adult horses to determine the effect of specimen preparation and the influence of anatomically separate regions on the microscopic structure of the esophagus. The effects of 3 fixative solutions (formalin, Bouin’s fixative and Karnovsky’s fixative) and 4 histologic staining procedures (hematoxylin and eosin, Gomori’s trichrome, Laidlow’s reticulum, and orceinelastin) were compared. Density-dependent image analysis was used to compare the relative contributions of elastic and reticular fibers in esophageal connective tissue for each region. Cross-sectional dimensions of the tissue layers which comprise the esophageal wall were obtained by light microscopic measurement and were compared for each region. The mucosal surface structure was examined by scanning electron microscopy. Our results indicate that specimen preparation has significant effects on the structural integrity of esophageal tissues. Bouin’s fixative was inferior to the other fixatives in this regard. Furthermore, there are extensive regional differences in esophageal microstructure. Formalin-fixed tissues stained with either hematoxylin and eosin or Gomori’s trichrome appear the most suitable for routine quantitative morphologic studies of the equine esophagus.
Reduced, oxidized, and protein-bound glutathione concentrations in normal and cataractous lenses in the dog
Authors: Gelatt Kirk N. , Bruss Michael , DeCostanza Susan M. , Noonan Norine E. , Das Noveen D. , Wolf E. Daniel
Published: February 2025

Amounts of reduced, oxidized, and protein-bound glutathione (gsh) were measured in normal and cataractous lenses of pups and adult dogs. Lenses from pups included normal lenses from clinically normal pups, clear lenses from Beagle pups bred for glaucoma, and congenital cataractous lenses from Miniature Schnauzer pups. Lenses from adults included normal lenses from normal mixed-breed dogs, congenital cataractous lenses from Miniature Schnauzers, and complete mature cataractous lenses from clinical patients of different breeds.

Glutathione in the normal lenses from pups and adult dogs is predominantly reduced gsh; oxidized gsh is about 2.1% to 2.6% of the reduced gsh values. The reduced gsh values are lower in normal pups [7.08 μmoles/g (wet wt) of lens] than in adults [7.83 μmoles/g (wet wt) of lens]; reduced gsh values decrease further in cataract formation. The decrease in oxidized gsh values parallel those of reduced gsh, except in the advanced cataracts of clinical patients in which oxidized gsh [0.045 μmoles/g (wet wt) of lens] was 9% of the gsh values.

The gsh bound to soluble and insoluble lens proteins of congenital cataractous Miniature Schnauzer pups was significantly (P < 0.01 and P < 0.02, respectively) lower per gram of protein than that in pups with normal lenses. However, the soluble and insoluble protein-bound gsh of congenital cataractous lenses of adult Miniature Schnauzers and lenses in clinical patients with mature cataracts [based on μmole of gsh/g (wet wt) of lens] were not significantly different (P > 0.05) from that in adult dogs with normal lenses.
Reversal of the neuroleptanalgesic effect of droperidol-fentanyl in the dog by 4-aminopyridine and naloxone
Authors: Booth Nicholas H. , Hatch Roger C. , Crawford Lester M.
Published: February 2025

In dogs, the effects of 4-aminopyridine (4-ap) and naloxone hydrochloride, administered iv, were determined on the duration of neuroleptanalgesia (“sleep time”) induced by an im injection of droperidol-fentanyl. Duration of neuroleptanalgesia produced by droperidol-fentanyl was significantly (P < 0.01) decreased by the combined iv administration of 4-ap and naloxone.

A mixture of 4-ap (0.5 mg/kg of body weight) and naloxone hydrochloride (0.04 mg/kg), administered iv, markedly antagonized the cns effects of an im dose (1 ml/9 kg) of droperidol-fentanyl. All dogs immediately regained a normal standing posture and were able to walk voluntarily without evidence of ataxia or tranquilization.

The im doses of droperidol-fentanyl (5 ml/9 kg or 5× the recommended clinical dose) were partially antagonized by 4-ap plus naloxone. Although the dogs were aroused by 4-ap plus naloxone, contained absorption of the large dose (5×) of droperidol-fentanyl from the im site was apparently responsible for the partial relapse that occurred. The iv administration of yohimbine hydrochloride, an α2-adrenergic blocking agent, failed to reverse droperidol-fentanyl in these animals. Nevertheless, 4-ap plus naloxone prevented respiratory arrest that can follow the use of large im doses of droperidol-fentanyl.

The cardiopulmonary effects of 4-ap (0.5 mg/kg) iv were determined in 1 dog after pentobarbital sodium anesthesia. A transient decrease in arterial pressure was induced by 4-ap. Respiratory minute volume increased slightly. Electrocardiographic alterations were not observed. Electrocardiographic perturbations, including a ventricular arrhythmia of short duration, were observed after the iv administration of a 5-fold dose (2.5 mg/kg) of 4-ap.

Cardiopulmonary effects of 4-ap (0.5 mg/kg) and naloxone hydrochloride (0.04 mg/kg) in combination iv were determined in 1 dog after iv anesthetization with droperidol-fentanyl (0.086 ml/kg) and pentobarbital sodium (10 mg/kg of body weight). A transient decrease in arterial pressure occurred, followed by a slight increase in pressure. Immediately after administration of the antagonists, additional pentobarbital sodium was necessary to maintain anesthesia. Respiratory minute volume increased 3-fold after administration of 4-ap and naloxone.

Ventricular arrhythmia did not develop after administration of 4-ap plus naloxone. However, the amplitude of the R wave decreased, whereas the amplitudes of the T and P waves increased.

Seemingly, 4-ap plus naloxone iv may have value in dogs for reversal of neuroleptanalgesia induced by droperidol-fentanyl (im and/or iv) after restraint, therapeutic, diagnostic, orthopedic, dental, and surgical procedures. These antagonists also may be valuable antidotes for an inadvertent overdose of iv or im droperidol-fentanyl.
Cross-protection by a chemically altered vaccinal strain of Pasteurella multocida in mice and hamsters
Authors: Wong J. C. S. , Kucera C. J.
Published: February 2025

A chemically altered type A strain of Pasteurella multocida was used to vaccinate mice and hamsters. The vaccinated animals were challenge exposed with type A, B, and E isolates of P multocida. A degree of protection was afforded the vaccinated animals against homologous and heterologous challenge-exposure strains.
Hemodynamic and respiratory effects of segmental subarachnoid analgesia in adult Holstein cows
Authors: Skarda R. T. , Muir W. W.
Published: February 2025

Hemodynamic measurements, arterial and mixed venous blood gas tensions, and pH were determined in 13 adult, nonpregnant Holstein cows (511.3 ± 77.3 kg) after subarachnoid injection of a 5% procaine hydrochloride solution (av dosage level of 0.162 ± 0.026 mg/kg) at the thoracolumbar (T13-L1) intervertebral space.

Segmental analgesia occurred within 8 to 12 minutes after completing the procaine HCl injection and extended between spinal cord segments T7 and L3 on both sides of the spinal column. The average duration of analgesia, as determined by the cows’ responses to superficial and deep muscular pinpricks, was 35.8 ± 8.5 minutes (25 to 60 minutes, min-max). Subarachnoid injection of procaine HCl caused a significant (P < 0.05) increase in heart rate and significant (P < 0.05) decreases in pulse pressure and rectal temperature. Cardiac output, stroke volume, left ventricular stroke work, left ventricular minute work, total peripheral resistance, arterial blood pressure, arterial and mixed venous blood gas tensions, pH, oxygen transport, oxygen uptake, pcv, and total solids did not change significantly (P > 0.05) from base-line values. Similarly, no significant changes (P > 0.05) were observed in a group of 5 control cows after subarachnoid injection of sodium chloride solution (1.5 ml, 0.9%) at the T13-L1 intervertebral space.

Segmental subarachnoid analgesia caused minimal circulatory disturbance and was well tolerated by adult, conscious, unsedated cows.
Metabolism and pneumotoxicity of 3-methyloxindole, indole-3-carbinol, and 3-methylindole in goats
Authors: Potchoiba Michael J. , Carlson James R. , Breeze Roger G.
Published: February 2025

Mixed function oxidation of 3-methylindole (3-MI) causes acute bovine pulmonary edema and emphysema in ruminants. 3-Methyloxindole (3-MOI) and indole-3-carbinol (IC) are considered to be early metabolites in the oxindole and carboxylic acid pathways of 3-MI metabolism. 3-Methyloxindole and IC were administered to goats to determine whether the respective pathways are involved in 3-MI-induced pneumotoxicosis. Sixteen goats were blocked into 4 groups according to age and body weight, and a 5th group was designated as the control. Two groups of 4 goats were given 2-hour infusions of [3H]3-MOI or [3H]IC (0.04 g of 3-MOI or IC/kg of body weight containing 1.84 μCi of [3H]3-MOI or [3H]IC/kg of body weight). Two additional groups of 4 goats were given 2-hour double-isotope infusions of [14C]3-MI plus [3H]3-MOI or [14C]3-MI plus [3H]IC (0.02 g of 3-MI plus 0.02 g of 3-MOI or IC containing 0.57 μCi of [14C]3-MI with 1.84 μCi of [3H]3-MOI or [3H]IC/kg of body weight). The 4 control goats received an equivalent amount of the infusion dose.

Goats given 3-MOI or IC did not develop signs of toxicosis or pathologic changes typical of 3-MI-induced pulmonary injury. These results demonstrate that 3-MOI, IC, or metabolites of their respective pathways are not responsible for 3-MI-induced acute pulmonary edema in goats.

Anion-exchange chromatography of urinary samples obtained from goats infused with [14C]3-MI plus [3H]3-MOI yielded 9 14C-peaks that co-chromatographed with 9 3H peaks. Chromatography of urinary samples from goats given [3H]IC yielded 2 peak areas which could not be identified as major 3-MI metabolites. The chromatographic profiles for 3-MI did not contain any peaks not accounted for by 3-MOI or IC. This indicates that 3-MOI and IC are early metabolites of 3-MI metabolism and that other significant pathways do not exist. The toxicosis associated with 3-MI must result from a metabolic step before the formation of 3-MOI or IC or from a 3-MI metabolite of a minor pathway not detected in the study.
Effect of chloramphenicol on serum salicylate concentrations in cats and dogs
Authors: Akesson Carin E. , Linero Patricia E. M.
Published: February 2025

Cats and dogs were treated with chloramphenicol (165 mg/kg; iv) and 30 minutes later were given salicylate (100 mg/kg; iv) and others (controls) were given salicylate only. Serum salicylate concentrations were measured. Chloramphenicol, described as a microsomal enzyme inhibitor, while not affecting the salicylate concentrations in cats, produced a significant increase in dogs, indicating a low biotransformation rate of salicylate in the feline species.
Activated partial thromboplastin time and activated coagulation time in monitoring heparinized cats
Authors: Greene Craig E. , Meriwether Emily
Published: February 2025

Cats were given heparin (iv or subcutaneously) at various dosages to determine the optimal dosage, route, and schedule for therapeutic anticoagulation. The activated coagulation time and activated partial thromboplastin time tests were used to evaluate heparin concentration. A dosage of 100 U/kg given iv produced an anticoagulation that was too brief and more potent than was desirable. Subcutaneous dosages of 250 and 375 U/kg produced therapeutically acceptable anticoagulation for 8 hours, whereas dosages of 500 and 1,000 U/kg caused an anticoagulation that was longer and more potent than was desirable. The activated coagulation time correlated well with the activated partial thromboplastin time in determining the degree of heparinization with certain limitations.
Adrenal and hepatic calcium stearate crystal deposits in dogs fed a thiamine-deficient diet
Authors: Pritzker Kenneth P. H. , Renlund Richard C. , Read Deryck H. , Cheng Pei-Tak , Harrington Daniel D.
Published: February 2025

The nature and histologic environment of birefringent crystals found incidentally at necropsy in the liver and adrenal glands of dogs fed a thiamine-deficient diet were studied. The crystals were identified as calcium stearate by ultrastructural and x-ray microdiffraction techniques. Crystals were observed intracellularly within cytoplasmic vacuoles and extracellularly within sinusoids. Generally, crystals were also observed in pair-fed controls that were given a purified diet (equal in weight to that consumed by the thiamine-deficient animals) plus supplemental thiamine. Crystal deposits were found in trace amounts in a few of the ad libitum-fed controls. Although thiamine deficiency may be involved in promoting crystal deposition in the adrenal cortex, calcium stearate crystal formation within the adrenal glands and the liver appears unrelated to dietary thiamine deficiency per se, but is probably related to deficiency of an unidentified nutrient in the purified thiamine-deficient diet.
Nerves to the cecum, ileum, and proximal loop of the ascending colon in cattle
Authors: Maala C. P. , Sack W. O.
Published: February 2025

Based on the examination of 20 specimens from cattle, the cecum, ileum, and proximal loop of the ascending colon were innervated by the cranial mesenteric plexus via the nerves following the ileocolic, cecal, and ileal arteries. The ileocolic nerves were usually separate nerves and did not form a plexus around the artery, except in 2 specimens where they formed a dense plexus around the ileocolic artery. The ileocolic nerves innervated the proximal loop of the ascending colon via the nerves accompanying the colic branches of the ileocolic artery. The ileocolic nerves were continued caudally as the cecal nerves. The latter nerves remained separate from each other, except where they communicated to form localized plexuses around the cecal artery. They supplied branches to the cecum dorsally and to the ileum ventrally, and ended in a network near the cecal apex. The lateral and medial surfaces of the ileocecocolic junction were innervated by fine branches from the ileocolic, as well as the cecal nerves. In 2 specimens, the cecal nerves formed elongated plexuses surrounding the cecal artery. The ileum was innervated by branches supplied dorsally by the cecal nerves and ventrally by nerves accompanying the mesenteric ileal and the first ileal arteries.

Macroscopic ganglia along the course of the ileocolic, as well as the cecal nerves, were not observed. The 1st ileal artery (off the cranial mesenteric) and the 1st and 2nd arterial colic branches (off the ileocolic) and their accompanying nerves supplied the ileal and colic lymph nodes, respectively. The small inconstant cecal lymph node caudal to the ileocecocolic junction was innervated by delicate fibers coming from the nerves following the first 2 cecal arterial branches.
Studies of Fusobacterium necrophorum from bovine hepatic abscesses: Biotypes, quantitation, virulence, and antibiotic susceptibility
Authors: Berg J. N. , Scanlan C. M.
Published: February 2025

Isolates of Fusobacterium necrophorum were obtained from 124 bovine hepatic abscesses (in 119 cattle) and from the ruminal contents of 12 cattle. Three biotypes (A, AB, and B) were found. Type A isolates were most common in hepatic abscesses, and type B isolates were most common in ruminal contents.

Virulence studies in mice indicated that type A isolates were more pathogenic than types AB or B isolates. The difference in virulences between types A and B isolates was not related to the toxicity of the endotoxin. Results of serotesting (passive hemagglutination) showed that a wide heterogeneity existed between isolates. Minimal inhibitory concentrations of antibiotics for 12 of the isolates (7 type A, 1 type AB, and 4 type B) were as follows: ≤ 0.06 IU of penicillin G/ml; ≤ 0.5 μg of cephaloridine/ml; ≤ 2 μg of chloramphenicol/ml; ≤ 0.06 μg of clindamycin/ml; ≤ 8 μg of erythromycin/ml; ≤ 128 μg of gentamicin/ml; ≤ 0.25 μg of oxytetracycline/ml; and ≤ 4 μg of tylosin/ml.
Immune responses of swine to oral inoculation with embryonated eggs of Ascaris suum
Authors: Rhodes M. B. , Keralis M. B. , Staudinger L. A.
Published: February 2025

Responses of swine to oral inoculation with embryonated eggs of Ascaris suum were monitored, using lymphocyte blastogenesis assays, indirect radioimmunoassays, and peripheral eosinophil counts (ec). Transient cell-mediated immune responses of peripheral lymphocytes were detected by a lymphocyte blastogenesis assay as early as postinoculation day (pid) 2, but were rarely positive for consecutive samples taken at 2-day intervals. Humoral antibodies were first detected at pid 6 to 17 by indirect radioimmunoassays in the various experiments. Positive cutaneous delayed hypersensitivity reactions were observed when pigs were tested at 6 to 7 weeks after inoculation. Histopathologic examination verified infiltration of lymphocytes into the lesions. The ec increased as early as pid 4 to 7 and showed a secondary increase after the 2nd oral inoculation of eggs to as high as 11,400/mm3 (44% of the total wbc). Subsequently, ec decreased rapidly 14 days after the last inoculation of eggs.
Bacterial antibiotic resistance: Frequency of gentamicin-resistant strains of Escherichia coli in the fecal microflora of commercial turkeys
Authors: Dubel Jacqueline R. , Zink Don L. , Kelley Lee M. , Naqi Syed A. , Renshaw Harland W.
Published: February 2025

The relationship of subtherapeutic feeding and parenteral injection of antibiotics to the presence of antibiotic resistant strains of Escherichia coli in the fecal microflora of commercial turkeys has been investigated. Cloacal swabs collected from 137 commercial turkeys were examined for E coli resistant to gentamicin. Gentamicin-resistant E coli organisms were isolated and tested for resistance to ampicillin, chloramphenicol, kanamycin, streptomycin, and tetracycline. Strains of E coli resistant to gentamicin were identified in 118 of 137 (86.1%) specimens evaluated. There were 5 different antibiotic resistance patterns exhibited by the gentamicin-resistant strains of E coli. All strains showed a common antibiotic resistance pattern of gentamicin, kanamycin, and streptomycin. The results of the antibiotic susceptibility tests were compared to the known history of antibiotic usage in each flock. There was no significant correlation between the use of subtherapeutic concentrations of antibiotics and the frequency of gentamicin resistant E coli. However, the frequency of gentamicin-resistant E coli was closely related to the age of the bird, with birds < 12 weeks of age being most likely to harbor E coli resistant to gentamicin. This age-dependent frequency of gentamicin-resistant E coli was associated with the common practice of dipping eggs in gentamicin and injecting newly hatched poults with gentamicin, but not with the feeding of subtherapeutic concentrations of antibiotics.
Effect of diet on the oral D-xylose absorption test in the horse
Authors: Jacobs K. A. , Norman P. , Hodgson D. R. G. , Cymbaluk N.
Published: February 2025

The effect of altering the diet the week before administering an oral D-xylose absorption test was studied in 4 horses. The horses fed a high energy diet of oaten chaff, oats, and corn had a significantly (P < 0.05) lower D-xy-lose absorption than did horses fed a low-energy alfalfa chaff diet. Factors that influence the oral D-xylose absorption test are discussed.
Equine lymphocyte antigens in a Welsh pony family
Authors: Swift Ruth V. , Mottironi Vilma D.
Published: February 2025

Lymphocytes from an extended family of Welsh ponies were tested in a microcytotoxicity test against Thoroughbred and Arabian horse-derived antisera, which defined 4 and 6 equine lymphocyte antigen (ela) specificities, respectively. Mixed leukocyte culture (mlc) tests were also performed. Welsh pony lymphocytes reacted to the Thoroughbred antisera. Most of the ponies’ lymphocytes showed reactivity to 2 of the Thoroughbred ela specificities, the offspring inheriting 1 antigen from each parent. Antigenic determinants were only partially demonstrated with Arabian antisera, although results indicated serologic identities among the ponies, which may reflect the historical background of the Welsh pony. There was no mlc reactivity between cells from most pairs of ponies that were ela-identical, as typed with the Thoroughbred antisera, but cells from 2 ela-identical pairs did react in mlc, indicating that mlc and ela determinants may be on separate loci, as in other species.
Neurotoxicologic effects of the nonionic contrast agent iopamidol on the leptomeninges of the dog
Authors: Spencer Crispin. P. , Chrisman Cheryl L. , Mayhew Ian G. , Kaude Juri V.
Published: February 2025

The effect of iopamidol on the leptomeninges was tested and compared with that of metrizamide and normal saline solution in 18 dogs. Pathologic and clinical effects were evaluated at 24 hours and 14 days after cisternal injection of iopamidol, metrizamide, or normal saline solution. Pathologic changes were evaluated by microscopic examination of serial csf samples and of sections of brain and spinal cord with the leptomeninges intact. Clinical changes were subjectively evaluated. Electromyograms and eeg were performed on each dog after physical and neurologic examination.

There were no changes seen in neurologic status, electromyogram, or eeg in any of the dogs immediately after subarachnoid injection nor at 24 hours or 14 days later. Pathologic changes were limited to mild, moderate, or severe patchy hemorrhagic leptomeningitis seen at 24 hours after iopamidol or metrizamide was injected. The severity of changes were judged to be similar with both these agents. The csf analysis and histologic evaluation of brain and spinal cord sections revealed a neutrophilic response to iopamidol and a mononuclear response to metrizamide. These findings indicate that iopamidol has minimal neurotoxicologic effect on the leptomeninges and therefore has merit as a myelographic agent.
Effect of xylazine hydrochloride on canine splenic weight: An index of vascular capacity
Authors: Hubbell John A. E. , Muir W. W.
Published: February 2025

Splenic weight, an index of changes in vascular capacity, was used to assess the effects of xylazine hydrochloride in anesthetized dogs. Intravenous xylazine (0.01, 0.1, and 1 mg/kg) produced dose-dependent decreases in vascular capacity as assessed by decreases in splenic weight which were significant (P < 0.05) at the 1 mg/kg dose. Phenoxybenzamine, an α-adrenergic receptor blocking drug, prevented the splenic contractile response to xylazine. Propranolol, a β-adrenergic receptor blocking drug, did not alter the splenic contractile response to xylazine.

Intravenous xylazine (0.1 and 1 mg/kg) produced significant (P < 0.05) decreases in heart rate, splenic arterial flow, and systolic, mean, and diastolic blood pressures. Central venous pressure increased significantly (P < 0.05) in dogs given the 1 mg/kg dose.
Diagnosis of histoplasmosis and blastomycosis by an antiglobulin hemagglutination test
Authors: Khansari Nematollah , Segre Diego , Segre Mariangela
Published: February 2025

An antiglobulin hemagglutination test was developed for detection of antibody directed to Histoplasma capsulatum and Blastomyces dermatitidis. The substances responsible for spontaneous agglutination of erythrocytes were removed from histoplasmin and blastomycin by vacuum dialysis, and partial purification of the antigens by gel filtration chromatography on Sephadex G-150 allowed removal of additional nonantigenic material which competed with the antigens for binding on the erythrocyte surface. The test was sensitive enough to detect antibodies in sera which were negative by complement fixation, immunodiffusion, or both, but it failed to discriminate reliably between antibody directed to H capsulatum and antibody directed to B dermatitidis. Erythrocytes sensitized with partially purified blastomycin produced some false-positive reactions with normal canine sera; this was corrected by diluting the antigen before sensitization of the erythrocytes.
Antibody response of cows to Escherichia coli pilus antigen K99 after oral vaccination with live or dead bacteria
Authors: Moon H. W. , McDonald J. S.
Published: February 2025

Pregnant cows were given primary oral vaccinations with live or dead Escherichia coli of the K99 pilus antigen type. The live E coli vaccine was fed in broth for 3 days (5 cows) and the dead E coli vaccine was fed daily for 6 to 11 weeks (4 cows). Five control cows were fed broth without bacteria. All of the cows were subsequently given a parenteral (subcutaneous) booster vaccination with a bacterin that contained K99 antigen. Serum, colostrum, postcolostral milk, saliva, and tears from all cows were tested for K99 antibody at intervals during the experiment.

None of the cows had antibody before vaccination. Control cows and those given the dead E coli oral vaccine did not have detectable antibody after the primary vaccination. Two cows in the live E coli vaccine group had low titers of antibody in serum or colostrum after primary vaccination. However, none of them had antibody in postcolostral milk. After the parenteral booster vaccination, all cows in the live E coli vaccine group and some of those in the dead E coli oral vaccine and control groups had antibody in serum and milk. Antibody titers in the live E coli vaccine group tended to be higher than those in the 2 other groups. However, the differences were not significant (P = 0.07). There was antibody in saliva or tears from some cows in the live E coli vaccine and control groups, but only after the parenteral booster vaccination. Seemingly, oral vaccination was not an effective means of stimulating K99 antibody production in colostrum or milk of cows.
Vaginal and uterine microflora of adult dogs
Authors: Baba E. , Hata H. , Fukata T. , Arakawa A.
Published: February 2025

Aerobic and anaerobic microflora were identified and quantitated in 82 vaginal and 78 uterine samples obtained from mature bitches during different stages of the estrous cycle. The mean ± sd of total bacterial counts/100 mg of vaginal contents of the 82 bitches was log 5.0 ± 1.5, ranging from log 2.4 to log 8.8. The count at the estrous stage (log 7.8 ± 0.7) was significantly higher (P < 0.05) than that at the anestrus (log 4.4 ± 1.0), pregnancy (log 5.9 ± 1.3), and postpartum (log 5.1 ± 1.5) stages. The common organisms isolated from the vaginas were Bacteroidaceae, streptococci, Pasteurella spp, and mycoplasmas. Organisms were isolated from 48 (68%) of 78 uterine samples. The range of total counts/100 mg of uterine contents was from log 1.6 to log 8.3. Staphylococci and mycoplasmas were frequently isolated from the uterine contents. Although many uterine microfloras were similar to vaginal microfloras, some uterine culture had a single isolate identified. There were no pathologic findings in most of the uteri. Seemingly, vaginal bacteria frequently flow into the uterus, yet they rarely cause uterine infection.
Experimental transplacental transmission of canine herpesvirus in pregnant bitches during the second trimester of gestation
Authors: Hashimoto A. , Hirai K. , Suzuki Y. , Fujimoto Y.
Published: February 2025

The effects of canine herpesvirus (chv) on fetuses were studied after iv inoculation of pregnant bitches in the 2nd trimester of gestation. Cesarean sections were performed on 2 bitches that were inoculated with chv on the estimated 30th day of gestation. Bitch M-1 had 2 mummified fetuses and bitch M-2 had 4 mummified and 2 dead fetuses and 3 live-born pups. Infection by chv was confirmed histopathologically by the presence of focal areas of necrosis associated with intranuclear inclusion bodies in heart muscle sections of 1 dead fetus; chv was not recovered from other organs. Abortion occurred between the 2nd and 3rd week after inoculation of another pregnant bitch inoculated with chv on the estimated 30th day of gestation. Two bitches inoculated with chv on the estimated 40th day of gestation gave birth prematurely to 10 pups. The detection of characteristic herpesviral lesions in various organs and the reisolation of chv from the liver, spleen, kidneys, and lungs of premature pups indicated chv infection.

Transplacental infection of fetal pups by chv resulted in their death and subsequent mummification. It appears that abortion and premature birth also may occur in pregnant bitches infected during the 2nd trimester of gestation.
Natural killer cell activity in adult gnotobiotic dogs
Authors: Krakowka Steven
Published: February 2025

An in vitro assay for natural killer cell activity by canine peripheral blood leukocytes was developed, using chromium-51-labeled heterologous (Vero) and homologous (Madin-Darby canine kidney, canine melanoma, and canine thyroid adenocarcinoma) target cells. Transformed tumor cell lines proved highly susceptible to natural killer-mediated lysis. Leukocytes from adult gnotobiotic dogs possessed levels of activity comparable to that observed in conventional animals.
Effects of tendon transfer on the canine scapulohumeral joint
Authors: Vasseur P. B. , Pool R. R. , Klein K.
Published: February 2025

Surgical techniques for correcting medial or lateral instability of the scapulohumeral joint in conditioned research dogs were evaluated. Lateral instability was created by severing the lateral joint capsule and the tendon of insertion of the infraspinatus muscle. In 4 dogs, the tendon of origin of the biceps brachii muscle was then transferred to a position lateral to the greater tubercle in an effort to improve lateral stability. In 3 control dogs, lateral instability was induced, but attempt was not made to stabilize the joint.

Medial instability was created by severing the tendon of insertion of the subscapularis muscle and the medial joint capsule. In 3 dogs, the tendon of origin of the biceps brachii muscle was transferred to a position under the lesser tubercle. In 2 dogs, a portion of the tendon of insertion of the supraspinatus muscle was transferred to a medial location. In 3 control dogs, attempt was not made to stabilize the joint.

The control dogs (n = 6) demonstrated mild-to-moderate weight-bearing lameness for 7 to 14 days after surgical induction of joint instability and thereafter had normal limb usage. Dogs having had tendon transfer procedures recovered normal limb usage in 4 to 6 weeks and thereafter behaved normally.

At necropsy, all joints appeared stable, and the surgical repairs were intact. A variety of joint surface abnormalities consistent with degenerative joint disease was observed, but no consistent pattern was assignable to any given surgical manipulation.
Furazolidone-induced congestive cardiomyopathy in ducklings: Regression of cardiac lesions after cessation of furazolidone ingestion
Authors: Van Vleet John F. , Ferrans Victor J.
Published: February 2025

Newly hatched male White Pekin ducklings (n = 92) were allotted to 2 groups of 46 each and fed 750 mg of furazolidone (fz)/kg of feed either for 8 weeks (group 1) or for 4 weeks followed by 4 weeks of no fz intake (group 2). Regression of fz-induced toxicosis was observed in ducklings of group 2 after cessation of fz consumption, as evidenced by decreased mortality, progressive decrease in ascites, and increases in body weight gains. Necropsy of 8-week survivors revealed decreased frequency and severity of ascites in ducklings of group 2. The severity of fz-induced cardiac alterations also was diminished, with a decrease in left ventricular dilatation score and an increase in absolute heart weights in 8-week survivors in group 2. Further evidence of regression of fz-induced congestive cardiomyopathy after cessation of fz ingestion was gained from development of intermediate cardiac damage severity scores and frequency and severity of ascites at necropsy in ducklings (previously studied) examined after 4 weeks of fz feeding, compared with those found in group 1 (fz 8 weeks) or in group 2 (fz 4 weeks, no fz 4 weeks) of the present study. Furazolidone-induced cardiac disease in ducklings offers an attractive model for studies of the pathogenesis of congestive cardiomyopathy and cardiac failure.
Failure to transmit Sarcocystis species from ox, sheep, goats, moose, elk, and mule deer to raccoons
Authors: Dubey J. P. , Blagburn Byron L.
Published: February 2025

Meat infected with Sarcocystis cruzi of ox, S tenella of sheep, S hemionilatrantis of mule deer, S capracanis of goats, S wapiti of elk, and S alceslatrans of moose was fed to 6 Sarcocystis-free raccoons, 1 raccoon for each species of Sarcocystis. None of the raccoons shed Sarcocystis sporocysts in the feces.