bluuebunny/crossref_metadata_2025 huggingface dataset:
Complications of retrograde contrast urethrography in dogs and cats
Authors: Johnston Gary R. , Stevens Jerry B. , Jessen Carl R. , Osborne Carl A.
Published: February 2025

Urinary bladder lesions varying histologically from a focal hemorrhagic cystitis to a diffuse transmural fibrinonecrotic cystitis were encountered in 11 of 14 dogs and cats euthanatized 1 day after retrograde urethrography. Focal-to-diffuse hemorrhagic urethritis was histologically encountered in 14 of 14 dogs and cats euthanatized 1 day after retrograde urethrography. Lesions in the urinary bladder and urethra were not reversible within 14 days and were evident histologically in 10 of 15 urinary bladders and 11 of 15 urethras of dogs and cats euthanatized 14 days after retrograde urethrography.

During urethrography, iatrogenic mural leakage of contrast media into the bladder wall or bladder wall rupture was encountered radiographically in 6 of 15 dogs and 3 of 14 cats. However, macroscopic evidence of bladder rupture was encountered in only 1 male dog at necropsy.

Immediately after retrograde urethrography, macroscopic hematuria occurred in 12 of 15 dogs and 9 of 14 cats. Microscopic hematuria was not encountered in dogs or cats euthanatized 14 days after urethrography. Pyuria was encountered less frequently and was present in only 2 cats euthanatized 14 days after urethrography.

One day after urethrography, urinary tract infection characterized by urine cultures with > 105 microbes/ml was encountered in 4 of 29 dogs and cats. All animals with urinary tract infection were female dogs or cats. At day 14, only 1 female cat had a positive urine culture.

Seemingly, the technique of retrograde urethrography was the cause of the encountered lesions.
Toxicity of gentamicin in red-tailed hawks
Authors: Bird J. E. , Walser M. M. , Duke G. E.
Published: February 2025

Gentamicin sulfate at dosage levels of 10 and 20 mg/kg of body weight was administered twice daily iv to redtailed hawks. Clinical signs, water consumption, and changes in blood chemical values were monitored, Tissues were examined grossly and ultrastructurally, using light and electron microscopy. Clinical signs of weakness and apnea were attributed to gentamicin-induced neuromuscular blockade in the 20-mg/kg group. Serum values of aspartate transaminase, alanine transaminase, cholesterol, inorganic phosphorus, total protein, dbumin, and uric acid increased in some birds. There was a decrease in periodic acid-Schiff staining of proximal tubular brush borders. Increased numbers of cytoplasmic lysosomes, many of which contained myelin figures, in renal epithelial cells were seen at the ultrastructural level. All birds given 20 mg/kg died. Both dosage levels were considered toxic in red-tailed hawks.
Pathophysiologic features of swine dysentery: Cyclic nucleotide-independent production of diarrhea
Authors: Schmall L. M. , Argenzio R. A. , Whipp S. C.
Published: February 2025

Net electrolyte and water transport and unidirectional Na+ fluxes were examined in ligated colonic loops of clinically normal pigs and in pigs with swine dysentery (etiologic agent Treponema hyodysenteriae) in the presence or absence of theophylline. In normal pigs, theophylline abolished net Na+ absorption via a reduction in the lumen-to-blood flux, decreased Cl- absorption, and increased HCO3-accumulation in the lumen. In infected pigs, all net ion transport was abolished, with the addition of theophylline producing little effect. The absence of net Na+ absorption in infected pigs was also the result of a decreased lumen-to-blood flux. Seemingly, colonic malabsorption may be the primary transport alteration in swine dysentery.

Concentrations of cyclic adenosine monophosphate (cAMP) and cyclic guanosine monophosphate (cGMP) were measured in samples of colonic mucosa from normal and infected pigs after in vitro exposure to a Ringer's solution containing 0 or 20 mM theophylline. Basal values of cAMP or cGMP did not increase in infected colonic mucosa. There was a diminished capacity of the infected mucosa to respond to theophylline. Alterations in ion transport in conjunction with measurements of cAMP and cGMP indicated that the pathogenic mechanism(s) in swine dysentery were not similar to those of Salmonella, Shigella, Vibrio cholerae, or Escherichia coli diarrhea.
Platelet-fibrin embolism in a rhesus macaque: Angiographic and pathologic studies comparing fluorescein and indocyanine green
Authors: McDonnell Peter J. , Flower Robert W. , Green W. Richard
Published: February 2025

A male rhesus macaque was found to have what appeared to be numerous platelet-fibrin emboli in retinal vessels in the perimacular area. Indocyanine green (icg) dye fluorescence and fluorescein angiograms of the fundus demonstrated leakage of fluorescein, but not icg, from the involved arterioles. Histopathologic changes in the eyes included occlusion of retinal and choroidal vessels with platelet-fibrin emboli, inner retinal ischemia, ischemic injury to the parafoveal capillary bed distally to occlusion of precapillary arterioles, and retinal exudate limited to the regions of capillary damage.

Differential leakage of fluorescein may be explained by the difference in binding affinities of the 2 dyes to blood protein: 20% to 40% of the circulating fluorescein is unbound, and 98% of icg is bound to serum albumin. Simultaneously or serially performed angiograms with fluorescent probes of different sizes might be used to obtain a qualitative measure of vascular integrity in persons with embolism, diabetic retinopathy, sickle cell retinopathy, vasculitis, and other disorders known to produce focal retinal and choroidal vascular occlusion.
Comparison of the effects of disodium ethylenediaminetetraacetate, theophylline, and deoxycholic acid on colonic ion transport and permeability
Authors: Argenzio Robert A. , Whipp Shannon C.
Published: February 2025

The effects of ethylenediaminetetraacetate (edta), theophylline, and deoxycholic acid (dca) on colonic ion transport and permeability were examined in an isolated loop system of the pig colon. The 3 agents abolished net water absorption, but only edta and dca induced an increase in mucosal permeability. Theophylline resulted in active bicarbonate secretion and increased the transmural electrical potential difference, whereas dca resulted in a dose-dependent inhibition of the theophylline-stimulated potential difference and antagonized or abolished the effect of theophylline on ion transport. A similar inhibition of the sodium transport potential across the mucosa resulted with dca. The effects of dca on the potential difference were immediate and reversible and paralleled the changes in colonic permeability. These results are consistent with the hypothesis that the mechanism of bile acid-induced diarrhea is through an increase in mucosal permeability and/or mucosal damage. Evidence of an active secretory process was not demonstrable with this preparation.
Isovolumetric indices and humoral cardioactive substance bioassay during clinical and experimentally induced gastric dilatation-volvulus in dogs
Authors: Orton E. Christopher , Muir William W.
Published: February 2025

Plasma collected from 6 experimentally induced and 29 clinical cases of gastric dilatation-volvulus was assayed for cardioactive substances utilizing isolated canine papillary muscles. The results were correlated with in vivo isovolumetric indices of myocardial contractility observed during experimental gastric dilatation-volvulus in the dog.

Cardioactive substances were not detected during experimental gastric dilatation-volvulus. Two experimental dogs showed a cardiostimulatory response and 4 experimental dogs showed a cardiodepressant response following gastric decompression. Cardioactive substance bioassays correlated well with isovolumetric indices in experimental dogs. The variable response in cardioactive substance bioassay observed in experimental dogs was consistent with clinical gastric dilatation-volvulus bioassays which produced a widely variable response ranging from strongly cardiostimulatory to strongly cardiodepressant.
Virus-induced interferon production in canine lymphoid cell cultures
Authors: Tsai Shaw C. , Appel Max J.
Published: February 2025

Virus-induced interferon (ifn) production in canine lymphoid cells was studied, using Newcastle disease virus as principal inducer. It was found that spleen cells at a concentration of 5 × 106 cells/ml with Newcastle disease virus at a multiplicity of infection of 1, incubated at 37 C in 5% CO2 for 24 hours, produced highest titers of ifn. Among the lymphoid cells from different tissues, ifn production was in the order of spleen = bone marrow > thymus > mesenteric lymph node ≥ peripheral blood lymphocytes. Macrophages did not produce ifn, and virus-induced ifn production in spleen cells did not depend on the presence of phagocytic mononuclear cells. These optimal conditions and macrophage independence are different from those of mitogen-induced ifn production in canine lymphoid cells.
Influence of mycoplasma preinfection on the expression of Moraxella bovis pathogenicity
Authors: Rosenbusch R. F.
Published: February 2025

Two mycoplasmas have been recovered commonly from the eyes of cattle with mycoplasmal conjunctivitis and from those with infectious bovine keratoconjunctivitis. Six calves inoculated with Mycoplasma bovoculi and another 6 calves inoculated with Ureaplasma sp were subsequently challenge exposed with a strain of Moraxella bovis to determine the latter's pathogenicity. Four control calves not previously inoculated with mycoplasmas were challenge exposed with 106 piliated Moraxella bovis organisms per eye. Pathogenicity of the Moraxella bovis challenge inoculum was evaluated by length of the conjunctival colonization period and appearance of keratitis. The M bovoculi-inoculated calves had extended colonization (more than 21 days) and keratitis which appeared at 6 to 15 days after challenge exposure, both in calves sampled every 2 days and in those not sampled until keratitis developed. Calves inoculated with Ureaplasma sp did not develop keratitis and only 2 of them had extended colonization. Control calves (given Moraxella bovis organisms only) did not develop keratitis and only 1 calf had extended colonization. When the same Moraxella bovis challenge inoculum was given to 2 gnotobiotic calves, extended colonization occurred without keratitis. Similar results were seen in 2 yearling calves given 2 doses of ultraviolet irradiation previous to challenge exposure. Marked association with surface epithelial cells was seen with M bovoculi, whereas low association with surface epithelial cells was seen with Ureaplasma sp in an indirect fluorescent antibody test on conjunctival and corneal epithelial cells obtained from 2 calves infected with M bovoculi and 2 calves infected with Ureaplasma sp.
Comparison of serum biochemical and hepatic functional alterations in dogs treated with corticosteroids and hepatic duct ligation
Authors: DeNovo Robert C. , Prasse K. W.
Published: February 2025

Differentiation of increased serum alkaline phosphatase (alp) activity associated with nonhyperbiiirubinemic cholestasis in dogs from that which occurs after corticosteroid induction was attempted, using various hepatic diagnostic enzymes and hepatic function tests. Nonhyperbilrubbinemic cholestasis was created in 5 dogs by ligation of the right hepatic duct; 5 sham-operated dogs served as controls. Corticosteroid induction of alp was created in 5 dogs by 11 daily doses of 3 mg of dexamethasone phosphate/kg, given iv; 5 sham-treated dogs served as controls. The period of evaluation was 12 days. Enzymes measured daily were alp, γ-glutamyltransferase (γGT), leucine aminopeptidase (lap), alanine aminotransferase (alt), and arginase (arg). Sulfobromophthalein (bsp) dye excretion, ammonia tolerance tests, test for serum bile acid concentrations, and electrophoresis for serum alp isoenzyme activity were done on days 1, 6, and 12.

Serum alp, alt, and γGT activities increased significantly (P < 0.05) in all dogs subjected to hepatic duct ligation and those treated with dexamethasone. The onsets of increased activity, rates of increase, maximal activity, and rates of decline varied among the enzymes and according to treatment. Neither hepatic duct ligation nor dexamethasone treatment caused significant changes in lap and arg activities. Dexamethasone-treated dogs had significantly higher (P < 0.05) bsp retention on days 6 and 12. Ammonia tolerance test results were in usual limits in all dogs, Serum bile acid concentrations increased after both hepatic duct ligation and dexamethasone treatment; however, the increases were significantly different (P < 0.05) from control values in dogs with hepatic duct ligation on days 6 and 12. Electrophoresis revealed an indistinct steroid-induced alp isoenzyme band in 1 dexamethasone-treated dog on day 12.
Rhesus macaque red blood cells frozen with 40% glycerol and stored at −80 C
Authors: Valeri C. R. , Valeri D. A. , Gray A. , Leavy P. D. , Contreras T. J. , Lindberg J. R.
Published: February 2025

Red blood cells of rhesus macaques cryopreserved with 40% (w/v) glycerol and stored at − 80 C had freeze-thaw-wash recovery values of 87%, 24-hour posttransfusion survival values of 85%, and life-span values of 13 days. Liquid and freezing methods of preserving rbc were studied in the macaques.
Intracapsular and intraosseous vascular supply to the mature dog's coxofemoral joint
Authors: Kaderly Robert E. , Anderson Bettina G. , Anderson Wesley D.
Published: February 2025

The intracapsular and intraosseous arterial supply to the mature dog's coxofemoral joint was investigated using a vascular injection, tissue-clearing technique in 6 mixed-breed dogs.

Ascending arteries of the femoral neck, arising from an extracapsular vascular ring at the base of the femoral neck, penetrated the articular capsule and traveled subsynovially over the surface of the femoral neck. These intracapsular arteries formed an incomplete intracapsular vascular ring at the junction of the femoral head and neck.

Bony components of the acetabulum, ie, ilium, ischium, and acetabular bones, received intraosseous vascular supply from the nutrient artery of the ilium and minute vessels entering nutrient foramina around the rim of the acetabulum. The femoral head received branches (epiphyseal arteries) from the ascending arteries of the femoral neck at the intracapsular vascular ring.

Epiphyseal arteries formed anastomosing vascular arches of decreasing caliber up to the subchondral bone of the femoral head. The proximal femoral metaphysis, particularly the femoral neck, received vascular supply from 4 sources: (i) branches from the epiphyseal arteries on the surface of the physeal scar which descended, penetrating the physeal scar, (ii) distally directed branches from the intracapsular vascular ring, (iii) ascending nutrient vessels from the trochanteric fossa, and (iv) terminal branches of the ascending nutrient artery of the femur.
Canine gestation length: Variation related to time of mating and fertile life of sperm
Authors: Concannon Patrick , Whaley Steven , Lein Donald , Wissler Richard
Published: February 2025

Variation in canine gestation length was studied in a Beagle colony (n = 290) in which apparent gestation length, estimated as the interval from the day of first mating to the day of parturition, ranged from 57 to 72 days, and averaged 65.3 ± 0.2 days. The interval from the day of the peak in luteinizing hormone (lh) to parturition was less variable and ranged from 64 to 66 days and averaged 65.1 ± 0.1 days (n = 54). Apparent gestation lengths ≤ 61 days all resulted from mating ≥ 3 days after the lh peak; those ≥ 68 days all followed initial or single matings occurring ≥ 2 days before the lh peak. Fertile single matings 3 days before the lh peak provided evidence that the potential postcoital fertile longevity of canine sperm is at least 6 days and thus contributed, along with variability in the onset of estrus, to the observed variation in apparent gestation length in the dog.

The limited range in the interval from the day of the preovulatory lh peak to the day of parturition (64, 65, or 66 days) demonstrates a considerable regularity in the sequential events of gestation in the dog.
Isolation of Mycobacterium kansasii from lymph nodes of cattle in the United States
Authors: Jarnagin Jerald L. , Himes Elmer M. , Richards William D. , Luchsinger Donald W. , Harrington Rube
Published: February 2025

The isolation of 6 strains of Mycobacterium kansasii from bovine lymph nodes is reported. Occasional isolations of this organism from cattle lymph node lesions provides further evidence of its pathogenicity in domestic animals. The isolates were similar as determined by biochemical and serologic examinations. Histopathologic changes induced by this organism relative to those by M bovis and factors regarding source of infection are discussed.
Segmental epidural and subarachnoid analgesia in conscious horses: A comparative study
Authors: Skarda R. T. , Muir W. W.
Published: February 2025

Six adult horses were used to eompare the effects of segmental epidural analgesia (sea) and segmental subarachnoid analgesia (ssa). A 17-gauge Huber point directional needle was used to place a catheter with stylet into the epidural space or the subarachnoid space at the lumbosacral intervertebral junction and to catheterize the thoracolumbar epidural or subarachnoid space. The position of the catheter was confirmed radiographically. A 2% solution of mepivacaine hydrochloride was used at average doses of 80 mg (4 ml) to produce sea and 30 mg (1.5 ml) to produce ssa.

Onset of analgesia in response to superficial and deep muscular pinprick stimulations was significantly (P < 0.05) faster in horses with ssa than with sea (8.0 ±1.9 minutes vs 15.8 ± 3.8 minutes). Maximal thoracolumbar analgesia extended from spinal cord segments T14 to L3 on both sides of the spinal column during ssa and from T12 to L2 on one or both sides during sea. Duration of analgesia lasted significantly (P < 0.05) longer in horses with sea than in those with ssa (80.8 ± 16.9 minutes vs 44.8 ± 14.5 minutes). There was a significant (P < 0.05) increase in subcutaneous temperature at the right and left 18th thoracic (T18) dermatomes and decreases of respiratory rate and rectal temperatures in horses with sea. Respiratory rate and rectal temperature were not significantly (P > 0.05) decreased in horses with ssa. Epidural and subarachnoid injections of mepivacaine hydrochloride solution did not significantly (P > 0.05) affect heart rate, systolic, diastolic, and mean arterial blood pressures, pulse pressure, arterial blood gas tensions (Paco2, Pao2), arterial pH, hematocrit, and total solid concentrations. The benefits and potential complications of sea and ssa in horses are discussed.
Phagocytosis and intracellular killing of the contagious equine metritis organism by equine neutrophils in genital secretions
Authors: Bertram T. A. , Coignoul F. L. , Jensen A. E.
Published: February 2025

Equine neutrophils were combined with contagious equine metritis organism (cemo) or Escherichia coli in vitro in the presence of seminal plasma, uterine flushings, or Hanks's balanced salt solution (hbss). Phagocytosis and intracellular killing were estimated by bacterial culture and light and electron microscopy. With lysed neutrophils, the numbers of colony-forming units of cemo and E coli increased in seminal plasma and uterine flushings. Numbers of cemo decreased in hbss. The numbers of cemo increased more in the presence of seminal plasma than the other media. When neutrophils were in the various media, 29% to 32% of the cemo were phagocytized by 120 minutes. At all sampling times and in all media types, more E coli than cemo were observed to be associated with neutrophils. By 210 minutes' incubation in uterine flushings, seminal plasma, and hbss, 60% to 75% of the intracellular cemo were killed. Of the intracellular E coli in the various media, 85% to 90% were killed by 210 minutes. Seemingly, cemo is an extracellular pathogenic bacteria and immunoglobulins in seminal plasma and uterine flushings from horses not previously infected with cemo do not enhance cemo phagocytosis or intracellular killing.
Total protein and immunoglobulins G1, G2, and M in serum of calves persistently infected with bovine viral diarrhea virus
Authors: Coria M. F. , McClurkin A. W. , Bolin S. R.
Published: February 2025

Total serum protein and immunoglobulins (Ig) G1, G2, and M concentrations were investigated in 11 calves persistently infected with bovine viral diarrhea virus. These calves were allowed to suckle from their dams until weaned. A gradual increase in total protein was observed from birth to 12 months of age. There was a wide variation in Ig concentrations in pre- and postcolostrum sera. The IgG1 increased from the time of delivery of the calves to the 5th month, decreased by the 10th month, and then stabilized through the 12th month. The IgG2 increased from birth to 10 months and remained stable through 12 months. The IgM increased from birth to the 11th month, and then decreased sharply by the 12th month.
Serum concentration of bile acids in guinea pigs as an indicator of liver damage caused by aflatoxins
Authors: Baetz A. L. , McLoughlin M. E.
Published: February 2025

Serum concentrations of glycocholic acid (ga) and glycodeoxycholic acid (gda) and serum activity of aspartate aminotransferase (ast) were determined after guinea pigs had been fed 0, 0.005, 0.010, 0.015, 0.020, or 0.030 mg of aflatoxin B1 equivalents daily for 21 days. Mean serum concentrations for the 20 control guinea pigs were ga, 3.70 µmole/L; gda, 0.12 µmole/L; and ast, 59.7 IU. Concentrations of ga and gda in treated guinea pigs were significantly higher than those in controls (P < 0.05) at doses of aflatoxin ≥ 0.010 mg/day. The highest serum concentrations of bile acids were in guinea pigs given the higher doses of aflatoxin. Activities of ast in treated guinea pigs were significantly higher than those in controls for only 2 dosage levels (0.010 and 0.030 mg/day). Bile acids in the serum of guinea pigs was a more sensitive indicator of liver damage caused by aflatoxin than was ast.
Systemic and local intestinal antibody response in dogs given both infective and inactivated canine parvovirus
Authors: Nara Peter L. , Winters Karen , Rice Jacqueline B. , Olsen Richard G. , Krakowka Steven
Published: February 2025

Systemic and local immune responses were evaluated in dogs given infective canine parvovirus (cpv) and 2 administrations of inactivated cpv 6 months later. Before the inactivated cpv was given, a jejunal cannulation was performed on the animals. During infective cpv administration, concentrations of class-specific copro- and sero-immunoglobulin (Ig)G, IgA, and IgM were determined by enzyme-linked immunosorbent assay. High concentrations of both copro- and sero-IgM, as well as a moderate increase in the concentrations of sero-IgG and copro-IgA, were detected within 3 days after experimental challenge. Hemagglutination inhibition titers correlated with both serum anti-cpv IgG and IgM early and serum anti-cpv IgG in the later states of infection. After 2 oral administrations of inactivated cpv, class-specific jejuno-, copro-, and sero-IgG, IgM, and IgA anti-cpv antibodies also were determined by enzyme-linked immunosorbent assay. High concentrations of jejuno-IgM and moderate levels of jejuno-IgG and IgA were found. Copro-IgM was not detected in the feces; however copro-IgG and IgA were. Also, no correlations were found to exist when sero-IgM and IgG were compared with jejuno- and coproantibody concentrations throughout the experimental period. Thus, it appears that the immune responses to cpv include both a secretory component of the intestinal mucosa and a systemic component of peripheral lymphoid tissues. Application of the modified Witzel's enterostomy to this study of local intestinal immunity proved beneficial. The technique was well tolerated by experimental animals and allowed for simple, multiple sample collections of intestinal contents for virus and antibody determinations with apparently minimal alterations in the luminal environment.
Evaluation of anastomoses of small intestine in dogs: Crushing versus noncrushing suturing techniques
Authors: Bone David L. , Duckett Kermit E. , Patton Clark S. , Krahwinkel D. J.
Published: February 2025

Fifteen dogs were used to compare simple interrupted crushing and noncrushing single-layer small intestinal anastomoses. Groups of 5 dogs each were used to evaluate both techniques at 3 postsurgical times—days 4, 21, and 42.

There were no significant differences between the 2 techniques at the evaluations. Grossly, there were marked adhesion formations at the 3 evaluation times. Luminal diameters at the anastomotic site indicated there may have been only slightly more stenosis with the noncrushing technique.

Bursting pressure studies determined that the anastomotic strengths of the 2 techniques were not measurably different statistically. However, their bursting strengths had greatly increased from day 4 to day 21. There were also significant increases in bursting strengths of jejunal segments caudal to the anastomotic sites from day 4 to day 42.

Subjective histopathologic evaluations of anastomotic sites revealed that the types and amounts of inflammation, collagen content, continuity of layers, and severity of peritonitis were not different within each time.

It was concluded that both techniques for small intestinal anastomoses in the dog have equal value.
Lamb model in the study of immunity to enteropathogenic Escherichia coli infections
Authors: Gregory D. W. , Cardella M. A. , Myers L. L.
Published: February 2025

Three groups of ewes were vaccinated with formalin inactivated, whole cell, aluminum hydroxide adjuvanted bacterins prepared from capsulated enteropathogenic Escherichia coli (eec). Lambs born to and suckling these ewes, compared with lambs of nonvaccinated control ewes, were highly resistant to homologous eec challenge exposure. Lambs of ewes vaccinated with products prepared from K99 antigen-positive, noncapsulated E coli were highly resistant to heterologous eec challenge exposure.

In both cases, lambs of vaccinated ewes had significantly (P < 0.005) less morbidity and mortality, fewer challenge inoculum-type E coli per rectal swab evaluation, and had superior weight gains over a 4-day period. Immunoglobulin assay of 122 lamb sera (collected 12 hours after birth) failed to reveal any correlation between serum immunoglobulin values and morbidity or mortality. When tested by plate agglutination technique, using whole cell antigens, or by reverse radial immunodiffusion, using purified capsular antigens, colostral whey samples of vaccinated ewes did not have increased capsular antibody titers. The K99 serum antibody values of K99 antigen-vaccinated ewes were markedly higher than were those of ewes vaccinated with other bacterins or of control ewes.
Effect of antimicrobial agents and corticosteroids on bovine polymorphonuclear leukocyte chemotaxis
Authors: Jayappa Kuchappa G. , Loken Keith I.
Published: February 2025

The effect of certain antimicrobial agents and corticosteroids on bovine polymorphonuclear leukocyte chemotaxis was investigated. Peripheral blood was fractioned by density-gradient centrifugation, using Ficoll-Hypaque. The chemotactic assay was performed in modified Boyden chambers, using Micropore filters, and the chemotactic response was measured by the leading-front technique. Tetracyclines, streptomycin, and penicillin had no effect on chemotaxis at concentrations normally achieved in blood during systemic treatment. However, higher concentrations that were achievable with local therapy, such as intramammary injection or topical application, inhibited the chemotactic response. This inhibition was eliminated by serum. Dexamethasone stimulated polymorphonuclear leukocyte chemotaxis with the effect being manifested after the cells were incubated with the drug for 3 hours. Hydrocortisone caused slight inhibition of chemotaxis, whereas prednisone and prednisolone had no effect.
Net absorption of 3-methylindole and indole in cattle after oral administration of l-tryptophan
Authors: Hammond Andrew C. , Huntington Gerald B. , Breeze Roger G.
Published: February 2025

The time course and quantity of 3-methylindole (3MI) and indole absorbed after oral administration of l-tryptophan (trp) was determined in 2 steers. The relationship between the appearance of 3MI and indole in the rumen and blood plasma to absorption of 3MI and indole was also studied.

Two Hereford x Angus steers with portal vein, mesenteric vein, and femoral (steer 1) or iliac (steer 2) artery catheters were used. Absorption rates from the portal drained viscera (net absorption) of 3MI and indole were determined by the product of portal and arterial concentration difference and blood flow. Blood flow was determined by primed continuous infusion of p-aminohippuric acid into a mesenteric vein. Three absorption measurements 30 minutes apart were taken at midpoint times of 0, 12, 24, 36, and 48 hours after oral administration of 0.4 g of trp/kg of body weight. Steer 1 was dosed twice resulting in a total of 45 absorption measurements.

Net absorption of 3MI and indole peaked at an average of 1.05 and 0.81 g/hr, respectively. By 48 hours, 29.2% and 15.3% of the trp dose were accounted for by 3MI and indole absorption, respectively. Closed system in vitro incubations of trp with ruminal fluid from the same 2 steers resulted in a trp to 3MI conversion of 23.2% and a trp to indole conversion of 10.7%. Net absorption of 3MI and indole closely followed and was correlated with concentration of 3MI and indole in ruminal fluid and blood plasma. 3-Methylindole and indole are rapidly and quantitatively absorbed in cattle after production from trp in the rumen.
Enzyme-linked immunosorbent assay for detection of bovine Immunoglobulin G1 antibody to a protoplasmic antigen of Mycobacterium paratuberculosis
Authors: Yokomizo Y. , Merkal R. S. , Lyle P. A. S.
Published: February 2025

An enzyme-linked immunosorbent assay (elisa) was developed for the detection of antibodies to Mycobacterium paratuberculosis in the sera of cattle. This assay was designed to minimize the nonspecific elisa reactions caused by immunoglobulin (Ig)M by measuring only IgG1 antibodies against a protoplasmic antigen from the organism. The elisa detected IgG1 antibodies in the sera of 58% of cattle with positive fecal cultures for M paratuberculosis compared with detection of 45% of culture-positive animals with an immunodiffusion test. In addition to its sensitivity, the elisa apparently is highly specific because only 4% of the sera from fecal culture-negative animals gave a false-positive result.
Effect of salicylates on intestinal secretion in calves given (intestinal loops) Escherichia coli heat-stable enterotoxin
Authors: Wise C. M. , Knight A. P. , Lucas M. J. , Morris C. J. , Ellis R. P. , Phillips R. W.
Published: February 2025

The inhibitory effect of salicylates on intestinal secretion in 1- to 5-day-old calves given Escherichia coli heat-stable enterotoxin (st)-induced intestinal fluid response was investigated. Purified st was diluted in isotonic saline solution to obtain 1:10, 1:25, 1:50, 1:75, and 1:100 dilutions. Each dilution (1 ml) was inoculated into ligated loops in the distal part of the jejunum of each calf. Acetylsalicylic acid (aspirin) given orally (100 mg/kg) at 4 hours before st was inoculated did not substantially alter the intestinal fluid response to st. Sodium salicylate (iv) infusion, begun simultaneously when, or at 1 hour after, st was inoculated, significantly (P < 0.05) decreased fluid accumulation in those loops inoculated with st dilutions of 1:25 or greater. The sodium and potassium concentrations of the accumulated fluid did not differ significantly between or within treatment groups. These results indicate that sodium salicylate infusion may be beneficial in treating enterotoxic colibacillosis in calves. Aspirin given orally at the dose used in the present study, would not have any beneficial effect.
Removal of the cecum, including the ileocecocolic junction, and its effects on digestibility in cattle
Authors: Maala C. P. , Smith D. F. , Hintz H. F. , Sack W. O.
Published: February 2025

The cecum and ileocecocolic junction in each of five 7-month-old Holstein steers were removed. Two steers of the same breed and age were sham-operated. All steers survived and were subjected to a digestibility experiment for 16 weeks. Digestibility of dry matter, neutral-detergent fiber, acid-detergent fiber, and cellulose decreased (P < 0.05) during postsurgical weeks (psw) 1 to 4, but not during psw 16. However, digestibility of protein and hemicellulose was not significantly (P < 0.07) influenced by the operation. Digestibility of the previously described components was not significantly different from that in 2 sham-operated steers.

The mean daily weight gain of the cecectomized steers decreased during psw 1 to 4; however, it started to increase at psw 8 so that at psw 16 it approached preoperative values. The mean daily weight gain of the sham-operated steers also decreased during psw 1 to 4, but was higher than the preoperative values at psw 14. The difference in mean daily weight gains between the cecectomized and sham-operated steers was insignificant.

The consistency of the feces of the cecectomized steers was loose to watery for a period of about 4 weeks after surgery. At psw 16, the feces were firm, but not of normal consistency. Feces of the sham-operated steers were loose after surgery, but returned to normal consistency after approximately 7 days.

Adhesions developed at the surgical site and involved the ileum, the proximal loop of the ascending colon, and the adjacent mesentery and greater omentum. The ileum was large and thick-walled and was expanded at its junction with the colon. The cecal artery and vein were intact. Except for a slightly contracted ileocecal fold, postsurgical lesions were not observed at the surgical site of the sham-operated steers.
Bovine leptospirosis: Bacteriologic versus serologic diagnosis of cows at slaughter
Authors: Thiermann A. B.
Published: February 2025

Blood for serologic examination and kidneys for bacteriologic cultural examination were collected from 204 cows slaughtered in an Iowa packing plant during August to October 1981. By the microscopic agglutination test on the 200 serum samples which were collected, 29 (14.5%) were positive—22 samples (10.8%) had agglutinin titers to hardjo, 4 (2%) to pomona, and 5 (2.5%) to other serovars. With the enzyme-linked immunosorbent assay, 79 samples (39.5%) were positive—53 (26.5%) to hardjo and 36 (18%) to pomona. Leptospiras were isolated from 13 (6.4%) of the kidneys (n = 204) examined. Characterization indicated that 7 isolates were hardjo; 3, grippotyphosa; and 2, pomona (1 isolate was lost during first subculture). Three of the hardjo isolates and 1 of the grippotyphosa isolates were obtained from cows that were seronegative by the microscopic agglutination test.
Enzyme-linked immunosorbent assay for serum antibody to bovine respiratory syncytial virus: Comparison with complement-fixation and neutralization tests
Authors: Gillette K. G.
Published: February 2025

An indirect enzyme-linked immunosorbent assay (elisa) for the detection of serum antibody to bovine respiratory syncytial virus (brsv) was developed and compared with complement-fixation (cf) and viral neutralization (vn) tests. Tissue culture-grown viral antigens were used in the tests. Serum samples from various sources were compared, including serum samples from 10 calves which were infected experimentally with brsv by aerosol exposure. The elisa compared favorably with the vn test for detecting serologic responses and for detecting passively acquired antibody in young calves. Approximately 98% (109/111) of field serum samples which were positive by the vn test were also positive by elisa. The elisa and the cf test both failed to detect early appearing (1 to 4 weeks after exposure) antibody in 2 experimental calves with subclinical infection with brsv. The cf test appeared to be less specific in that it gave positive reactions with some sera which were negative by both the elisa and the vn test. The cf test did not detect antibody in 50% of serum samples obtained at the farm from young feeder calves which were positive by both elisa and the vn test.

The elisa appears to be a sensitive and specific serologic procedure for detecting serum antibody to brsv and has the advantage of giving test results within several hours, whereas the vn test requires 5 to 6 days for completion.
Demonstration of colonies of Anaplasma marginale in the midgut of Rhipicephalus simus
Authors: Potgieter Fred T. , Kocan Katherine M. , McNew R. W. , Ewing S. A.
Published: February 2025

Rhipicephalus simus nymphs were allowed to feed on a cow experimentally infected with the BW-strain of Anaplasma marginale from Republic of South Africa, and they were studied as adults. Colonies were demonstrated by light microscopy in midgut epithelial cells of adult ticks that were unfed (as adults), incubated, or prefed for 72 hours on a cow. The colonies occurred in 5 different morphologic types (1 to 5) that were similar to those described previously for a Virginia isolate of A marginale in Dermacentor andersoni. The colony density (number of colonies/0.001 mm2 midgut tissue examined) ranged from 0 to 2.0 and was highest in unfed ticks that were not incubated (mean 0.566).

Colonies observed by light microscopy were sectioned for study with the electron microscope. The colonies contained both electron-dense forms and reticulated forms. The organisms in type 2 and 3 colonies appeared to be attached to one another, and those in type 4 and 5 colonies occurred separately. Small particles were seen within the limiting membrane of some organisms. A few colonies contained a dense matrix and were surrounded by many small electron-dense particles.
Sequential response of milk leukocytes, albumin, immunoglobulins, monovalent ions, citrate, and lactose in cows given infusions of Escherichia coli endotoxin into the mammary gland
Authors: Guidry A. J. , Ost M. , Mather I. H. , Shainline W. E. , Weinland B. T.
Published: February 2025

Changes in concentrations of both the cellular and the humoral components of milk are known to occur during mastitis. This study was conducted to determine temporal changes in the concentrations of leukocytes, albumin, immunoglobulins (Ig), monovalent ions, lactose, and citrate in milk during the initial phases of simulated mastitis. Ten cows whose udders were pathogen free and had milk leukocyte counts of < 0.5 × 106/ml were used. Two dosages of Escherichia coli endotoxin were administered to simulate various degrees of mastitis. Two quarters in each cow were infused with the endotoxin and the other 2 served as controls. Quarter milk samples were collected frequently before and after infusion.

Within 2 hours after infusion of a 100-µg dose of endotoxin, clinical mastitis was observed in most of the infused quarters. Leukocytes, albumin, IgG1, and conductivity showed significant increases. Values before infusion and at postinfusion (pi) hour 2 were as follows: leukocytes, 0.33 and 3.65 × 106/ml, respectively; albumin, 0.38 and 4.49 mg/ml; IgG1, 0.34 and 0.79 mg/ml; and conductivity, 6.0 and 6.9 mmho. Average of the peak values and their average relative time of appearance after infusion were as follows: leukocytes, 28.82 × 106/ml at 16 hours; albumin, 9.37 mg/ml at 4 hours; IgG1, 1.35 mg/ml at 4 hours; and conductivity, 95.5 mmho at 10 hours. The IgG1 values tended to remain high in the presence of rapidly declining albumin concentrations, indicating the possibility of an active, rather than a passive, transfer of IgG1 from the circulation.

The response to the 10-µg dose of endotoxin ranged from subclinical to clinically mild mastitis with lesser cellular and humoral responses.
Seminal shedding of bluetongue virus in experimentally infected mature bulls
Authors: Bowen R. A. , Howard T. H. , Entwistle K. W. , Pickett B. W.
Published: February 2025

Sixteen bulls ranging in age from 2 to 11 years were experimentally inoculated with bluetongue virus to investigate the frequency and duration of seminal shedding of the virus. All bulls developed typical viremia, lasting 21 to 58 days, and they seroconverted 2 to 3 weeks after inoculation. Virus isolation was attempted from a total of 232 ejaculates, 163 (70%) of which were collected during the period of viremia.

Bluetongue virus was not isolated from any of the ejaculates collected from 11 of the 16 bulls. Virus was isolated from 9 of 52 ejaculates collected from the other 5 bulls during the period of viremia. In no instance was virus isolated from semen without concurrent isolation from blood.
Immunosuppression in goats inoculated with parainfluenza type 3 virus
Authors: Kennedy-Stoskopf Suzanne , Narayan Opendra , Hirsch Robert L.
Published: February 2025

The humoral and cellular immune responses of goats experimentally infected with an ovine isolate of parainfluenza type 3 virus (pi-3) were examined. Virus neutralization and enzyme-linked immunosorbent assays were used to determine antibody in the serum and csf. Lymphocyte stimulation, measured by [3H]thymidine incorporation into peripheral blood leukocytes, was used to determine cellular responses to phytomitogens and virus. There were significant suppression of peripheral blood leukocyte responses to T-cell mitogens early in the course of infection and delayed onset of virus-specific cell-mediated immunity. Delay in antibody formation did not occur. The suppression of mitogen response has been reported with other paramyxovirus infections. The importance of the suppressed cellular immune response for potentiating other infective agents is discussed.
Metabolism and renal handling of sodium arsenate in dogs
Authors: Tsukamoto Hidekazu , Parker H. R. , Peoples S. A.
Published: February 2025

Renal handling of sodium arsenate was studied in 5 dogs. Using a low dose (0.73 mg/kg of body weight) of sodium arsenate given iv, variable arsenite concentrations were detected in plasma and urine. Using a medium dose (7.33 mg/kg), the renal tubule cells were determined to be the probable sites of reabsorption of arsenate, reduction of arsenate to arsenite, and secretion or diffusion of the latter into urine. However, using a high dose (14.66 mg/kg), despite a similar pattern of reduction of arsenate to arsenite, marked reabsorption of arsenite into plasma took place instead of secretion or diffusion into urine. Because of reabsorption, the amount of arsenite in plasma (18.4 ± 3.5% of the total As) was about 3 times higher than that measured during the medium dose experiment (6.0 ± 1.0%).

During the clearance experiments which lasted 110 minutes, only 40% to 45% of the arsenate infused was excreted in urine, and a minimal amount of dimethylarsinic acid (dmaa) was detected. In contrast, by the next day, dmaa was the major metabolite excreted in urine, This excretion of As as dmaa was partly due to delayed excretion of 55% to 60% As that was stored in the body and was subsequently metabolized.
Rapid identification of dominant Brucella antigens, using a microagglutination test
Authors: Hennager Steven G. , Harris S. K. , Ewalt Darla R. , Jarnagin Jerald L.
Published: February 2025

A microagglutination test was used to identify Brucella dominant antigens from 400 Brucella and non-Brucella cultures. There was 100% agreement between microagglutination and tube agglutination tests in identifying dominant antigen.
Hyperglycemia and hypoinsulinemia during xylazine-ketamine anesthesia in Thoroughbred horses
Authors: Tranquilli W. J. , Thurmon J. C. , Neff-Davis C. A. , Davis L. E. , Benson G. J. , Hoffman W. , Lock T. F.
Published: February 2025

Plasma glucose and serum insulin concentrations in Thoroughbreds administered xylazine hydrochloride (1.1 mg/kg; iv) and ketamine hydrochloride (2.2 mg/kg; iv) at dosages sufficient to induce short periods of recumbency and anesthesia were measured. Samples of blood were collected from 6 adult horses before, during, and after the anesthetic period. Plasma glucose (mg/dl) was significantly increased above control (−30 minute concentration) from 15 to 150 minutes after xylazine administration with the peak value occurring at 30 minutes. Serum insulin (μU/ml) was significantly decreased from control from 5 to 90 minutes after xylazine administration, with the nadir occurring at 15 minutes. The alterations in plasma glucose and serum insulin concentrations in xylazine-ketamine-anesthetized horses were similar to the changes in xylazine-sedated horses.
Michel's medium as a preservative for immunofluorescent staining of cutaneous biopsy specimens in dogs and cats
Authors: Caciolo Paul L. , Hurvitz Arthur I. , Nesbitt Gene H.
Published: February 2025

Paired 3-mm skin biopsy specimens from 24 dogs and 11 cats with suspected autoimmune dermatopathies were stained with fluorescein-conjugated antisera. In each case, 1 specimen was immediately embedded in optimum cutting temperature compound, quick frozen to −30 C, processed, stained, and examined. The other sample was placed in Michel's transport medium, held for 7 days, and then processed, stained, and examined. The location, quality, and intensity of immunofluorescent staining (when positive) were then compared in the 2 specimens. There were no differences in the staining patterns between the specimens processed immediately and those held in Michel's medium, thus demonstrating the validity of preserving canine and feline skin biopsy specimens in Michel's medium for immunofluorescent examination.
Concentrations of testosterone in canine serum during late anestrus, proestrus, estrus, and early diestrus
Authors: Olson P. N. , Bowen R. A. , Behrendt M. D. , Olson J. D. , Nett T. M.
Published: February 2025

Serum testosterone concentrations in samples collected daily from 6 bitches for at least 60 days before the onset of diestrus were determined by radioimmunoassay. Mean serum concentrations (± SEM) of testosterone ranged from 31 ± 11 to 141 ± 63 pg/ml during late anestrus. Mean testosterone concentrations during proestrus ranged from 106 ± 29 to 239 ± 113 pg/ml, with the highest concentration (526 ± 225 pg/ml) occurring the day of the preovulatory surge of luteinizing hormone.

Although the ovaries may be sites of production during late anestrus, proestrus, estrus, and early diestrus, further investigation is necessary to determine whether testosterone has an important physiologic or endocrinologic function in the bitch (ie, sexual behavior, vaginal hypertrophy, and luteinizing hormone surge).