bluuebunny/crossref_metadata_2025 huggingface dataset:
Enzymuria as an index of renal damage in sheep with induced aminoglycoside nephrotoxicosis
Authors: Garry Franklyn , Chew Dennis J. , Hoffsis Glen F.
Published: January 2024

Acute nephrotoxicosis was induced in ewes by daily sc administration of gentamicin. Activity of 3 urine enzymes, γ-glutamyltransferase (ggt), β-N-acetylglucosaminidase (ags), and β-glucuronidase (grs), were measured during the development of aminoglycoside nephrotoxicosis. Measurements from timed, volume-measured urine samples were performed on days 0, 7, and 8. Measurements from urine samples obtained without volume measurement (spot samples) were performed daily. Urine ggt and ags activities were high 3 days prior to detection of high serum creatinine concentration and 1.5 days before the appearance of casts in the urine sediment; values consistently remained in the abnormal range until termination of the study. High urine grs activity was inconsistent and transient; serum ggt activity did not change during the course of the study. Urine ggt and ags activities expressed as total excretion per unit time and body weight, enzyme activity per unit volume, and as ratio of urine enzyme activity to urine creatinine concentration were strongly correlated. Urine ggt and ags, but not grs activities, are suitable indicators of renal tubular cell damage in sheep with aminoglycoside nephrotoxicosis. Urine ggt and ags activities indicate cellular changes occurring several days prior to the first indications of renal functional change.
Effect of Pasteurella haemolytica-derived endotoxin on pulmonary structure and function in calves
Authors: Slocombe Ron F. , Mulks Martha , Killingsworth Cheryl R. , Derksen Frederik J. , Robinson N. Edward
Published: January 2024

The role of endotoxin in the pathogenesis of acute pneumonic pasteurellosis is uncertain. Recently, we reported that Escherichia coli -derived endotoxin given by airway inoculation fails to induce lung injury in calves. Because Pasteurella haemolytica-derived endotoxin may differ substantially from E coli in its pathogenicity, we repeated these studies with Pasteurella endotoxin. Intratracheal inoculation of P haemolytica endotoxin caused hypoxemia and increased the alveolar-arterial oxygen differences without causing hypercarbia or changes in lung mechanical properties and volumes. In contrast, iv inoculation of endotoxin caused systemic hypotension, leukopenia, gas exchange impairment, increased total pulmonary resistance, and decreased dynamic compliance. Both routes of inoculation increased serum endotoxin concentrations and were associated with areas of pulmonary hemorrhage, edema, and acute inflammation. We concluded that P haemolytica-derived endotoxin is pathogenic by iv and airway routes of inoculation, and therefore differs from E coli endotoxin in its ability to induce lung lesions in calves.
Use of multiallelic human DNA probes to detect polymorphisms in the porcine genome
Authors: Troyer Deryl L. , Smith Joseph E. , Leipold Horst W.
Published: January 2024

Two human variable-number tandem repeat probes, pYNH24 and pYNA23, were examined for their possible ability to detect polymorphisms in the porcine genome. Useful DNA polymorphisms were detected in the porcine species, using both probes. In addition, results of Southern blot analysis of these markers in family studies indicated that the genome fragments obey mendelian laws of inheritance.
Effect of meal feeding on plasma volume and urinary electrolyte clearance in ponies
Authors: Clarke L. L. , Argenzio R. A. , Roberts M. C.
Published: January 2024

The effect of meal size and frequency on plasma volume, plasma aldosterone concentration and urinary Na and K clearances was determined in ponies. A daily maintenance ration of hay-grain pellets was provided either as a multiple feeding regimen, ie, 12 equal portions fed at 2-hour intervals, or as single large feedings, ie, half the ration fed every 12 hours at 0800 and 2000 hours. Only the effect of the single morning feeding was studied, using the latter regimen. Serial measurements of plasma volume were made by use of an indicator-dilution technique and indocyanine green (0.15 mg/kg of body weight, iv) that allowed repeated determinations at 2-hour intervals. Ingestion of the single large meal caused a 15% decrease in plasma volume by the end of a 1-hour feeding period. Feeding hypovolemia was confirmed by a coincident increase in plasma protein concentration (12%) and, in separate experiments, by analysis of postfeeding changes in the elimination of Evans blue dye. Plasma aldosterone concentration was significantly (P < 0.05) increased from 2 to 5 hours after feeding. Urinary Na clearance decreased in response to feeding and remained lower than the prefeeding value until 9 hours after feeding. Urinary K clearance increased from prefeeding and reached a peak value between 5 and 7 hours after feeding. Creatinine clearance was unaffected. In contrast, the aforementioned variables were unchanged during the multiple regimen. Results indicate that ingestion of a large concentrate meal by ponies causes periprandial hypovolemia, activation of the renin-angiotensin-aldosterone system, and a subsequent antinaturesis-kaluresis that lasts for several hours.
Potency of rapidly acting barbiturates in dogs, using inhibition of the laryngeal reflex as the end point
Authors: Turner Donald M. , Ilkiw Jan E.
Published: January 2024

Thiopental, thiamylal, and methohexital were administered to 30 dogs to determine equipotent doses necessary to inhibit laryngeal reflexes. The doses studied were 7.1, 10.0, 14.1, 20.0, and 28.3 mg of thiopental/kg of body weight; 5.7, 8.0, 11.3, 16.0, and 22.6 mg of thiamylal/kg; and 3.5, 5.0, 7.1, 10.0, and 14.1 mg of methohexital/kg. At 1, 2.5, 5, and 10 minutes after injection, the presence or absence of the laryngoscopic reflex, pedal reflex, and jaw tone were recorded. The times for return of each reflex, as well as the ability to walk 10 steps without assistance, were also recorded. Using the method of least squares, a probit analysis was performed on the quantal responses at 1 minute. The effective dose in 50% of the population for the laryngoscopic reflex was chosen as the end point for intubation, and the computed doses necessary to achieve this end point were 19.4 mg of thiopental/kg, 18.4 mg of thiamylal/kg, and 9.7 mg of methohexital/kg. When potencies of the drugs were compared with that of thiopental (1), thiamylal was found to be equipotent (1.06) and methohexital twice as potent (2.0). At the accepted clinical dose, recovery times for thiopental (71.1 ± 7.2 minutes) and thiamylal (75.3 ± 7.7 minutes) were similar, and twice that for methohexital (33.9 ± 4.6 minutes).
Sequential mesenteric arteriography in pony foals during repeated inoculations of Strongylus vulgaris and treatments with ivermectin
Authors: Holmes R. A. , Klei T. R. , McClure J. R. , Turk M. A. M. , Watters J. W. , Chapman M. R.
Published: January 2024

Semiselective mesenteric arteriography was performed at regular intervals (inoculation weeks [iw] 0, 11, 18, and 24) in 9 of 10 pony foals raised to be free of parasites. Fifty infective larvae (L3) of Strongylus vulgaris were administered weekly for 4 weeks, then every 2 weeks through the 20th week. Three ponies were given ivermectin (oral paste, 0.2 mg/kg of body weight) treatment at iw 8, 16, and 24. Four ponies were inoculated, but did not receive ivermectin, and a third group of 2 ponies acted as uninoculated controls. Control ponies did not have gross or arteriographic lesions, whereas the inoculated untreated ponies had gross and progressive arteriographic lesions typical of verminous arteritis. Arteriographic lesions in the ivermectin-treated inoculated ponies were not as severe those in the untreated inoculated group, and there was either a partial resolution or a lack of progression of arteriographic lesions in all treated ponies. One untreated inoculated pony did not have progressive arterial lesions as did the 3 others in the group, and may develop resistance to the parasite.
Influence of Rhodococcus equi on the respiratory burst of resident alveolar macrophages from adult horses
Authors: Brumbaugh Gordon W. , Davis Lloyd E. , Thurmon John C. , Savage Dwayne C.
Published: January 2024

Opsonized Rhodococcus equi activated the respiratory burst of resident alveolar macrophages (am) from adult horses in a logarithmic-linear, mass-related manner. The effect of R equi was not significantly different from that of equal masses of opsonized zymosan A. Therefore, R equi does not appear to attenuate the respiratory burst of equine am. The stimulatory effect of R equi was not reflected by increased production of superoxide anion (O2-), but increased activity of the hexose monophosphate shunt was observed. These results suggest a similarity between the respiratory burst of am from horses and that of am from rabbits. We concluded that resident am from adult horses do not produce O2- concurrently with an increase in activity of the hexose monophosphate shunt when stimulated with either opsonized zymosan A or opsonized R equi. This suggests that O2- is not an important component of the antibacterial defenses of equine am. Whether equine am are incapable of producing O2- or require different stimuli to produce it was not determined.
Survey of trichinosis in breeding and cull swine, using an enzyme-linked immunosorbent assay
Authors: Cowen Peter , Li Shugen , McGinn Thomas
Published: January 2024

Serum samples obtained from 40,927 swine at various locations in North Carolina between Aug 1, 1987 and July 31, 1988, were tested for antibodies to Trichinella spiralis, using an elisa based on a larval T spiralis excretory-secretory antigen. In the elisa, samples were considered to have positive results if the optical density (OD) reading was equal to or 5 times greater than the mean OD value of 4 negative-control sera from trichina-free swine. Of the 40,927 serum samples tested, 154 (0.38%) were positive by elisa; the rate for breeding swine was 0.35% (105/30,162), and the rate for cull swine was 0.45% (49/10,765). Of the 49 seropositive samples from cull swine, 11 were from out of the state, 22 had no identification, and 16 were known to originate from North Carolina. Seropositivity had a bimodally seasonal distribution, with peaks in March and September. There was no difference between the mean age of seropositive and seronegative swine, but males were at greater risk for seropositivity than were females. Pigs from lots with < 100 sera tested were at increased risk for seropositivity, as were pigs from the central coastal region of North Carolina.
Evaluation of two applanation tonometers in horses
Authors: Miller Paul E. , Pickett J. Phillip , Majors Lynda J.
Published: January 2024

Comparisons were made of measurements obtained in horses, using 2 applanation tonometers in vivo and in vitro. In vitro comparisons indicated that although neither instrument accurately recorded intraocular pressure (iop), compared with manometric measurements, results of both instruments indicated linear digression from manometric iop values that could readily be corrected, thereby accurately estimating iop in horses. For tonometer 1 (MacKay-Marg), calculated actual lop = 1.48 − 0.9 mm of Hg; and for tonometer 2 (Tono-Pen), calculated actual iop = 1.38 + 2.3 mm of Hg. The coefficients of determination (r2) values were markedly high (0.99 for both equations). In vivo comparisons in clinically normal horses did not reveal significant differences in measured 10P between the 2 instruments, and iop was not altered from baseline after auriculopalpebral nerve block. Mean (± sd) iop in clinically normal horses was 23.5 ± 6.10 mm of Hg and 23.3 ± 6.89 mm of Hg, for tonometers 1 and 2, respectively.
Methods for detection of immune-mediated neutropenia in horses, using antineutrophil serum of rabbit origin
Authors: Jain Nemi C. , Vegad J. L. , Kono C. S.
Published: January 2024

Equine neutrophil antibody was raised in rabbits inoculated with equine neutrophils isolated to purity > 99.0%, using Percoll density-gradient sedimentation. Neutrophil antibody was detected by use of agar gel diffusion, leukoagglutination, indirect immunofluorescence, staphylococcal protein A and streptococcal protein G binding, and phagocytic inhibition techniques.

Precipitin lines and leukoagglutination were seen in antiserum dilutions of 1:4 and 1:64, respectively. The specific nature of leukoagglutination was characterized by the formation of rosette-like clumps of neutrophils. Specific bright membranous fluorescence was seen in neutrophils treated with the antiserum and exposed to fluorescein-conjugated goat anti-rabbit immunoglobulin, and staphylococcal protein A and streptococcal protein G. Whereas the indirect immunofluorescence and protein G-binding tests were equally sensitive and resulted in titer of 1:256, the protein A-binding test was less sensitive and resulted in titer of only 1:32. Nonspecific binding of protein A and protein G was noticed as uniform or patchy cellular fluorescence in a small number of neutrophils. Treatment of neutrophils with antiserum up to dilution of 1:8 resulted in a significant (P < 0.05) suppression of phagocytosis of opsonized zymosan particles.

Thus, protein G-binding and indirect immunofluorescence tests are highly sensitive to detect neutrophil antibody and may be used to diagnose immune-mediated neutropenias in horses and, possibly, in other animal species.
In vivo effects of chloramphenicol, tetracycline, and gentamicin on bovine neutrophil function and morphologic features
Authors: Paape M. J. , Nickerson S. C. , Ziv G.
Published: January 2024

Antibiotics that have been shown in vitro to have a detrimental effect on bovine polymorphonuclear leukocytes (pmnl) were injected into the mammary gland. Chloramphenicol, tetracycline, gentamicin, or phosphate-buffered saline solution (pbss) were administered to uninfected mammary quarters of four cows at recommended doses. Each cow received each of the 4 treatments. Total milk somatic cell count and N-acetyl-β-d-glucosaminidase activity in milk in response to drug, changes in ultrastructure of pmnl, and effects on in vitro percentage phagocytosis, reduction of nitroblue tetrazolium, and chemiluminescence were studied.

Chloramphenicol and tetracycline caused a significant (P < 0.01) increase in somatic cell count, compared with baseline values. During the first 12 hours, no effect on NAGase activity was observed. All 3 antibiotics caused a significant (P < 0.05) alteration of pmnl morphologic features. More abnormal pmnl (63%) were found in tetracycline-injected quarters. Gentamicin-injected quarters contained 33% abnormal pmnl, compared with only 5% for pbss-injected quarters. A significant (P < 0.01) decrease in percentage phagocytosis was observed for tetracycline and gentamicin. Tetracycline inhibited all chemiluminescence activity, whereas no effect was observed for the other 2 drugs. Nitroblue tetrazolium reduction was nonsignificant (P ≥ 0.05) decreased for the 3 drugs, compared with that for pbss controls. On the basis of our findings, we concluded that some antibiotics may be inhibitory to phagocyte function and, thereby, impair host defense mechanisms against invading microbes.
Epidemiologic study of bluetongue viruses in Central America and the Caribbean: 1986-1988
Authors: Homan E. Jane , Mo Claudette L. , Thompson Lee H. , Barreto Celio H. , Oviedo Marco-Tulio , Gibbs E. Paul J. , Greiner Ellis C. , _ _
Published: January 2024

Results of a prospective serologic and virologic study of ruminant livestock in Central America and the Caribbean islands revealed bluetongue virus (btv) to be enzootic in the 9 countries participating in the study. Bluetongue virus serotypes 1, 3, 6, and 12 were isolated from sentinel animals. To the authors’ knowledge, these are the first isolations of btv from the region studied and the first isolations of these serotypes in the Western Hemisphere. Clinical disease attributable to btv infection was not observed in sentinel animals. The incidence pattern, with respect to age and geographic location, was determined. The need to evaluate the epizootiologic features of arthropod-borne viruses (arboviruses) on a regional ecologic basis is stressed.
Identification of Bordetella avium antigens recognized after experimental inoculation in turkeys
Authors: Hellwig Dianne H. , Arp Lawrence H.
Published: January 2024

Sera and tracheal washings (tw) were used to identify antigens of Bordetella avium recognized during experimentally induced bordetellosis in young turkeys. Pooled sera and tw were examined for antibody by a microtitration agglutination test and by western immunoblotting. In addition, comparable samples collected from 1-day-old turkeys and uninoculated control turkeys also were examined. At least 8 outer membrane proteins of B avium were recognized in immunoblots of sera and tw from infected turkeys. Reactivity of tw in immunoblots was qualitatively similar but less intense, compared with reactivity of corresponding sera collected on postinoculation (pi) weeks 2, 3, and 4. Molecular weights of the major outer membrane proteins of B avium recognized by sera and tw at pi week 4 were 100,000, 97,000, 36,000, 31,000, 21,000, 18,000, 14,000, and < 14,000. A protein with a molecular weight of 55,000 reacted nonspecifically in all samples tested. Antibody, detectable by microtitration agglutination, was in sera of 1-day-old turkeys and in sera and tw of B avium-infected turkeys during pi weeks 2 to 4.
Characterization of release of tumor necrosis factor, interleukin-1, and superoxide anion from equine white blood cells in response to endotoxin
Authors: Seethanathan P. , Bottoms G. D. , Schafer K.
Published: January 2024

Direct effects of endotoxin (lipopolysaccharide [lps]) on equine wbc are known to stimulate the release of a variety of mediators including thromboxane, prostacyclin, and leukotrienes. In this study, 0.1 μg of lps/ml stimulated an early increase in tumor necrosis factor, succeeded by an increase in interleukin-1, but concentrations of lps up to 5.0 μg/ml caused no significant increase in superoxide anion release. The concentration of lps (0.1 μg/ml) used in this experiment was in the range of concentrations measured in plasma of some horses with gastrointestinal problems.

These results indicate that mediators released in response to low concentrations of lps may be responsible for many of the lps-induced pathophysiologic effects. This is indicated because concentrations of lps detected in plasma of some horses with severe gastrointestinal problems are approximately 0.1 μg/ml, a concentration that will stimulate cells to produce tumor necrosis factor, but will not stimulate any other measurable cytotoxic effect.
Effects of clustered drill holes on the breaking strength of the equine third metacarpal bone
Authors: Specht T. E. , Miller G. J. , Colahan Patrick T.
Published: January 2024

The breaking strength (stress at failure) of equine third metacarpal bones, with and without clustered drill holes, was determined in vitro. Paired ossa metacarpalia II-IV of 39 horses (n = 39) between 2 and 7 years old were tested in palmarodorsal 3-point bending. Four treatments were compared. Clustered 2.7- or 3.5-mm drill holes, in a 4- or 7-hole pattern, were made in the dorsal cortex of the distal diaphysis of the left third metacarpal bone. Undrilled right third metacarpi were used as controls. Bones with clustered drill holes failed by an oblique fracture through 1 or more drill holes, whereas undrilled bones failed with a middiaphyseal transverse fracture. Clustered drill holes acted as a stress concentrator and significantly (P < 0.05) decreased the stress required for failure. However, differences in breaking strength between treatment groups were not significant (P > 0.05).
Maternal-neonatal immunoregulation: Suppression of de novo synthesis of IgG and IgA, but not IgM, in neonatal pigs by bovine colostrum, is lost upon storage
Authors: Klobasa F. , Butler J. E. , Habe F.
Published: January 2024

Fifty-four neonatal pigs were allotted to 4 groups and reared in an electrically controlled automatic feeding device (autosow). Each group was reared on a different pool of bovine colostrum: fresh, stored 1 month, stored 6 months, and stored 8 years. Bovine and porcine immunoglobulins in the sera of these pigs, and in a group of conventionally reared pigs, were measured periodically during the first 42 days after birth. The maximal concentration of absorbed bovine immunoglobulin was reached between 12 and 18 hours and equaled or exceeded the amount of porcine immunoglobulin absorbed by the conventionally reared pigs. Large differences in the concentrations of the bovine immunoglobulin isotypes among the various pools of colostrum were positively correlated with concentration of these isotypes in the sera of the neonatal pigs fed these pools. Relative to their concentrations in colostrum, approximately 41% of the IgGl, 55% of the IgG2, 29% of the IgM, and 67% of the IgA was absorbed. The IgA was absorbed the best and IgM was least absorbed. Significant trends or differences in absorption were not observed among groups. Neonatal pigs given fresh colostrum, which had a higher fat content, had significantly more weight gain (P < 0.05). This occurred, despite the fact that the fresh colostrum had the lowest concentration of bovine immunoglobulin. Serum half-lives for bovine IgG1 and IgG2 were significantly less than for porcine IgG (P < 0.05), whereas the half-lives for bovine and porcine IgM and IgA were similar.

De novo-synthesized immunoglobulins were detectable in serum after 6 days; IgM concentrations reached a maximum at 15 days in neonatal pigs given stored, but not fresh, colostrum. The IgG and IgA concentrations steadily increased in all groups and were highest on day 42, when the study was terminated. Neonatal pigs ingesting fresh colostrum had significantly lower concentrations of de novo-synthesized IgG and IgA than pigs fed stored colostrum (P < 0.05). Concentrations in these pigs were also lower than those in conventionally reared pigs. This occurred, despite the lower immunoglobulin concentration in fresh colostrum, and correspondingly, the lower amount of bovine immunoglobulin in pigs that received this colostrum and absorbed it into their serum. In most instances, the amounts of immunoglobulin of any isotype absorbed from stored colostrum and the amount of de novo-synthesized immunoglobulin present 6 weeks later, were inversely correlated. Data indicated that a storage-labile, nonimmunoglobulin factor, in bovine colostrum is able to suppress de novo IgG and IgA synthesis by neonatal pigs.
Effects of chloride conductance inhibitors on fluid secretion into ligated ileal and jejunal loops in pigs
Authors: Forsyth G. W. , Gabriel S. E.
Published: January 2024

Compounds that prevent chloride transport in membrane vesicles have been tested for in vivo activity against the effects of intestinal secretory agents. Chloride channel blockers including diphenylamine-2-carboxylate, 4-acetamido-4′-isothiocyanostilbene-2,2′-disulfonate, 5-nitro-2-(2-phenylethylamino)benzoic acid, and α-phenylcinnamic acid were tested for effects on jejunal or ileal secretion in weanling pigs. Secretion was studied in ligated intestinal loops in a control state, during exposure to secretory concentrations of theophylline, and after prior treatment with cholera toxin. Increases in net fluid flux induced by either theophylline or cholera toxin were not prevented by adding chloride channel blockers into the intestinal lumen. Channel blocker concentrations that reduced chloride transport by > 50% in pig jejunal brush border vesicles did not cause significant changes in unidirectional blood to lumen chloride flux measured in situ. Several routes of administration of the specific chloride channel blocker α-phenylcinnamate failed to reduce fluid secretion induced by theophylline. Chloride channel blocker effectiveness appears to be significantly different between in vitro and in vivo experimental models.

In contrast to the chloride channel blockers, loperamide significantly reduced net fluid and chloride flux in ileal loops secreting fluid in response to theophylline. Antagonism of the production or actions of second messenger by loperamide was more effective than the chloride channel blockers in reducing conductive chloride transport associated with intestinal secretion.
Clinicopathologic and pathologic findings of herpesvirus-induced urinary tract infection in conventionally reared cats
Authors: Kruger John M. , Osborne Carl A. , Goyal Sagar M. , Pomeroy Kem A. , O’Brien Timothy D.
Published: January 2024

Clinicopathologic manifestations of induced infection of the feline lower urinary tract with bovid herpesvirus-4 (bhv-4, strain FCAHV) were characterized in 6 conventionally reared adult cats (2 sexually intact males, 2 castrated males, and 2 females). Two additional control cats were exposed with noninfected cell culture control inoculum. Clinical and radiographic signs of lower urinary tract disease were not observed in exposed or control cats. Microscopic hematuria was detected in urine samples collected by cystocentesis from 4 of 6 exposed cats and 1 of 2 control cats. Results of culture of urine for bacteria, maycoplasmas, ureaplasmas, and viruses were consistently negative. Low titer of serum bhv-4 (strain FCAHV)- neutralizing antibodies was detected in 4 of 6 exposed cats, but not in controls.

Gross abnormalities of the urinary tract were not observed in any cat. Light microscopic examination of serial sections of the lower urinary tract revealed mild focal lymphoid cystitis in 2 of 6 exposed cats, one of which also had increased amounts of connective tissue and proliferation of blood vessels in the urinary bladder lamina propria. Ninety days after initial exposure, bhv-4 (strain FCAHV) was reisolated from explanted urinary bladder tissues of 5 of 6 exposed cats. Virus was not isolated from tissues of control cats.

It was concluded that bhv-4 (strain FCAHV) establishes persistent urinary tract infection in conventionally reared adult male and female cats. However, persistent bhv-4 infection in cats may remain clinically inapparent.
Maturational development of drug-metabolizing enzymes in sheep
Authors: Kawalek J. C. , El Said K. R.
Published: January 2024

A qualitative and quantitative assessment was made of the development of hepatic drug-metabolizing enzymes (dme) in sheep as part of a study of the ability of the food-producing species to metabolize drugs. The following dme and components were measured in this study: cytochromes P-450 and b5 and nadph and nadh-dependent reductases associated with each of these cytochromes; cytochrome P-450-mediated reactions, including aniline and coumarin hydroxylases, aminopyrine N-demethylase, and 7-ethoxycoumarin 0-deethylase; a uridine diphosphoglucuronic acid glucuronyl transferase with 4-methylumbel-liferone as substrate; and glutathione-S-transferase with dinitrochlorobenzene and dichloronitrobenzene as substrates.

Amounts or activities of most of these components and enzymes increased up to and beyond the time of weaning. Amount of cytochrome b5 and uridine diphosphoglucuronic acid transferase activity were not affected by age, whereas nadph cytochrome c (P-450) reductase activity actually decreased after weaning. In some instances (eg, coumarin hydroxylase, cytochrome P-450, and dinitrochlorobenzene-glutathione-S-transferase), differences from preweaning dme values were observed only after sheep were ≥ 6 months old. All other dme activities were definitely increased, compared with the values in lambs before weaning (0 to 12 weeks old).

Approximately a third of the sheep studied had some type of clinical disease that might have affected the dme activities. Diseases were classified as sore mouth, pneumonia, foot rot, parasitism, and systemic bacterial infections. Except in a few instances, these diseases had minimal effect on dme activities measured in vitro. Variations in dme activities among healthy individual sheep were far more pronounced than differences in dme activities that might be attributed to 1 or more of the aforementioned disease states.
Evaluation of drug-induced prostatic involution in dogs by transabdominal B-mode ultrasonography
Authors: Cartee R. E. , Rumph P. F. , Kenter D. C. , Cooney J. C. , Frank D. , Haught J. , Leong P. , Humphries M. , Amaratunga P. , Zampaglioni N.
Published: January 2024

The relative antiandrogen-induced prostate involution activity of the newly synthesized hydroxyflutamide prodrug was compared with that of flutamide in 25 Beagles. Secondary antiandrogen activity of both drugs on the testes and mammary tissue was investigated. Daily oral administration of both compounds at 2 dosages (ie, 2.5 and 5.0 mg/kg of body weight) during a 7-week period was monitored by transabdominal ultrasonography of the prostate twice a week. Cross-sectional area estimates of the prostate gland calculated from oblique dorsoventral, and transverse sonographic measurements were diminished significantly in some of the treated dogs as early as day 14 of drug administration. All treated dogs had significant differences in reduction by day 47. Involution was related directly to dose (P < 0.05), but no difference was observed between test compounds. Differences in secondary antiandrogen activity were not remarkable. Flutamide was not found to have any activity advantage in vivo over hydroxyflutamide. It was concluded that ultrasonography can be a highly effective means of monitoring prostate size, and of monitoring drug-induced involution over time.
Influence of carbonated drinking water on tibia strength of domestic cockerels reared in hot environments
Authors: Kreider E. M. , Nelson S. M. , Harrison P. C.
Published: January 2024

To determine the effects of heat stress and drinking water treatments on physical characteristics of skeletal tissue, tibias of cockerels ranging in age from 4 to 11 weeks were tested for breaking strength. Birds were subjected to either a thermoneutral environment (21 ± 2 C) or a hot environment (37 ± 2 C) and supplied with either tap or carbonated drinking water. Breaking strength of tibias was reduced in the hot environment; however, consumption of carbonated drinking water in the hot environment resulted in bone strength comparable with that associated with thermoneutral environment (both types of water). Also, bones from birds of the carbonated water- 37 C treatment group had less phase breaks and tended to separate with a single break. Results indicate that hot environment and carbonated drinking water not only affect the previously reported morphologic and chemical characteristics of developing bone, but also their physical attributes.
Cardiovascular changes after bone marrow transplantation in dogs with mucopolysaccharidosis I
Authors: Gompf Rebecca E. , Shull Robert M. , Breider Michael A. , Scott Joseph A. , Constantopoulos George C.
Published: January 2024

Five dogs with mucopolysaccharidosis I, 3 of which had been treated with bone marrow transplantation (bmt), were evaluated for 20 months with electrocardiography, thoracic radiography, and M-mode and 2-dimensional echocardiography. Treated and untreated (control) dogs had widened P waves on ecg. Thoracic radiographs remained normal for all dogs throughout the study. Thickening of the mitral valve was observed on echocardiograms of dogs in both groups, but the untreated dogs appeared to have thicker valves. Concentrations of glycosaminoglycans in the mitral valves and myocardium were higher in control dogs than in treated dogs. Markedly large aortic root diameters were observed on echocardiograms in both untreated dogs, but aortic root diameters remained normal in treated dogs. Echocardiography, but not electrocardiography, was useful in monitoring heart enlargement in each dog. Dogs treated with bmt generally had less-severe cardiac changes and slower disease progression than control dogs.
Comparison of the width of the intervertebral disk space and radiographic changes before and after intervertebral disk fenestration in dogs
Authors: Dallman Mark J. , Moon Martha L. , Giovannitti-Jensen Ann
Published: January 2024

Intervertebral disk space widths were measured on lateral radiographs of 73 anesthetized dogs. Weight was found to have a significant (P < 0.01) effect on disk space width. Using weight-adjusted disk space width measurements for all subsequent studies, older (7- to 16-year-old) dogs and males had consistently, but not significantly, wider, disk spaces than did alternative groups. Cervical and lumbar intervertebral disk spaces tended to be wider than those in the caudal thoracic region. The widest cervical intervertebral disk spaces were C4-5 and C5-6 and the narrowest was C2-3. In the lumbar region, L2-3 was the widest disk space and L4-5 was the narrowest. Dachshunds generally had greater mean intervertebral disk space width than did other breeds of dogs.

Cervical (n = 6 dogs) and thoracolumbar (n = 6 dogs) disk fenestration resulted in narrow intervertebral disk spaces, regardless of breed. When a ventral approach was used in thoracolumbar fenestration, the mean intervertebral disk space was narrower than that resulting from use of a dorsolateral approach.

Spondylosis was found radiographically 1 to 4 years after intervertebral disk fenestration in 3 of 6 dogs that had cervical fenestrations and in 5 of 6 dogs that underwent thoracolumbar fenestration.
Diminution of aflatoxin toxicity to growing lambs by dietary supplementation with hydrated sodium calcium aluminosilicate
Authors: Harvey Roger B. , Kubena Leon F. , Phillips Timothy D. , Carrier Donald E. , Elissalde Marcel H. , Huff William E.
Published: January 2024

Hydrated sodium calcium aluminosilicate (hscas), an anticaking agent for mixed feed, was added to the diets of growing wethers (mean body weight, 34.0 kg) and was evaluated for its ability to diminish the clinical signs of aflatoxicosis. The experimental design consisted of 4 treatment groups of 5 wethers each, consuming concentrations of 0 g of hscas and 0 g of aflatoxin (af)/kg of feed (control; group 1); 20 g of hscas/kg (2.0%; group 2), 2.6 mg of af/kg (group 3); or 20 g of hscas (2.0%) plus 2.6 mg of af/kg (group 4). Wethers were maintained in indoor pens, with feed and water available ad libitum for 42 days. Lambs were observed twice daily and weighed weekly, and blood samples were obtained every 2 weeks for hematologic and serum biochemical analyses and for measurement of mitogen-induced lymphocyte-stimulation index. At the termination of the study, wethers were euthanatized and necropsied. Body weight gain was diminished significantly (P < 0.05) by consumption of 2.6 mg of af/kg of feed, whereas body weight of lambs consuming hscas plus af did not differ from that of control wethers. The af-alone treatment increased serum aspartate transaminase and γ-glutamyltransferase activities, prothrombin time, and cholesterol, uric acid, and triglyceride values and decreased albumin, glucose, and urea nitrogen values, and urea-to-creatine ratio. A 27% decrease in lymphocyte stimulation index, increased spleen weight (as a percentage of body weight), and decreased liver weight were induced by af-alone treatment. Results indicate that hscas may be a high-affinity sorbent for af, that 2.6 mg of af/kg of feed induces signs of aflatoxicosis in growing wethers, that lambs may not be as resistant to the effects of af as previously thought, that 2.0% hscas can substantially reduce the toxic effects of 2.6 mg of af/kg, and that sorbent compounds may offer a novel approach to the preventive management of aflatoxicosis in livestock.
Evaluation of praziquantel for treatment of experimentally induced paragonimiasis in dogs and cats
Authors: Bowman Dwight D. , Frongillo Marguerite K. , Johnson Robert C. , Beck Kathy A. , Hornbuckle William E. , Blue Julia T.
Published: January 2024

Praziquantel was used successfully for treatment of a small number of dogs and 1 cat infected with Paragonimus kellicotti. To further evaluate the usefulness of this drug in treating such infections, 7 cats and 7 dogs were inoculated orally with metacercariae (12 and 20 to 22, respectively) obtained from crayfish, then were treated after the infections became patent; 2 cats and 2 dogs served as noninfected controls. Beginning 1 week before infection, and continuing weekly thereafter, physical, hematologic, and fecal examinations were performed on each animal; thoracic radiography was performed every other week. By postinoculation week 6, all dogs given metacercariae had patent infection diagnosed on the basis of positive results of fecal examination. By postinoculation week 7, 5 cats had confirmed patent infection, but 2 cats given metacercariae never had patent infection or had signs of infection. Clinical signs of infection were minor and included increased respiratory tract noise, slight inducible cough, or mild dyspnea. Transient eosinophilia was detected in dogs around postinoculation week 3. Pretreatment radiography revealed cavitated lesions in cats only; pleural lines and patchy infiltrates in cats and dogs; or pneumothorax in dogs only. The treatment regimen consisted of 23 mg of praziquantel/kg of body weight given every 8 hours for 3 days; 1 infected cat and dog were not treated. By 11 days after treatment, eggs had disappeared from the feces of infected animals, and marked resolution of lung lesions was evident radiographically. The 2 untreated animals and 1 treated dog were euthanatized and necropsied to verify lesions and their resolution. All treated animals were considered cured of infection by use of this treatment regimen.
Effects of intra-articular administration of methylprednisolone acetate on normal equine articular cartilage
Authors: Trotter Gayle W. , McIlwraith C. Wayne , Yovich John V. , Norrdin Robert W. , Wrigley Robert H. , Lamar C. H.
Published: January 2024

The effects of the corticosteroid 6-α-methylprednisolone acetate on normal equine articular cartilage were evaluated, using the middle carpal joint in 4 clinically normal young horses. One middle carpal joint of each horse was injected 3 times with 100 mg of 6-α-methylprednisolone acetate, at 14-day intervals. The opposite middle carpal joint (control) was injected with 2.5 ml of lactated Ringer solution at the same intervals. Effects were studied until 8 weeks after the first injection. Evaluation included clinical and radiographic examination, and gross, microscopic, and biochemical evaluation of joint tissues.

Horses remained clinically normal during the study, and significant radiographic changes were not observed. Safranin-0 matrix staining intensity and uronic acid content were significantly (P < 0.05) lower and hydroxyproline content was significantly (P < 0.05) higher in articular cartilage of corticosteroid-injected joints vs control joints.
In vitro comparison of Thoroughbred and Standardbred racehorses with regard to local fatigue failure of the third metacarpal bone
Authors: Nunamaker David M. , Butterweck Diane M. , Black Jonathan
Published: January 2024

In vitro local fatigue testing of the third metacarpal bone from Thoroughbred and Standardbred racehorses was performed, using fully reversed cyclic bending. Strain number of cycle data were accumulated and indicated that significant difference did not exist between the 2 breeds. It was concluded that the marked difference in the incidence of fatigue failure in the third metacarpal bone (bucked shins, dorsal metacarpal disease) seen in Thoroughbreds and Standardbreds was not related to any differences between the 2 breeds in mechanical properties of the bone.
Defective function of leukocytes from cattle persistently infected with bovine viral diarrhea virus, and the influence of recombinant cytokines
Authors: Brown Gayle B. , Bolin Steve R. , Frank Dagmar E. , Roth James A.
Published: January 2024

Cattle persistently infected with bovine viral diarrhea (bvd) virus have decreased neutrophil and lymphocyte functions. We reevaluated these functions and further characterized the inhibition of persistent bvd virus infection in neutrophils, using sensitive kinetic assays. In addition, the influence of in vitro incubation of neutrophils with recombinant bovine interferon gamma (rBoifn gamma) and in vitro incubation of lymphocytes with recombinant bovine interleukin-2 was evaluated.

Significant (P < 0.05) decrease in random migration under agarose, Staphylococcus aureus ingestion, cytochrome-C reduction, iodination, antibody-independent cell-mediated cytotoxicity, oxidant production, and cytoplasmic calcium flux were observed in neutrophils from cattle persistently infected with bvd virus, compared with noninfected control cattle. Incubation of neutrophils from noninfected controls with rBoifn gamma significantly (P < 0.05) decreased random migration under agarose, cytochrome-C reduction, and cytoplasmic calcium flux. Neutrophils from cattle persistently infected with bvd virus also had decreased random migration under agarose after incubation with rBoifn gamma; in addition, antibody-independent cell-mediated cytotoxicity, elastase release, and cytoplasmic calcium flux were significantly enhanced. The rBoifn gamma induced significantly (P < 0.05) different effects on chemotaxis, cytochrome-C reduction, iodination, and cytoplasmic calcium flux of neutrophils from infected and control cattle. The rBoifn gamma was more effective at improving the function of neutrophils from cattle persistently infected with bvd virus, compared with neutrophils from controls.

Lymphocytes from infected cattle had decreased histogenesis in response to phytohemagglutinin, concanavalin A, and pokeweed mitogen. Incubation of those lymphocytes with recombinant bovine interleukin-2, with no mitogen present, significantly (P < 0.05) increased incorporation of [3H]thymidine. However, the response of lymphocytes to mitogen stimulation was not significantly increased by the presence of recombinant bovine interleukin-2, indicating that depression of in vitro lymphocyte histogenesis in the cattle persistently infected with bvd virus is not attributable to decreased production of interleukin-2.
Lysis of bovine platelets by Pasteurella haemolytica leukotoxin
Authors: Clinkenbeard Kenneth D. , Upton Melinda L.
Published: January 2024

Pasteurella haemolytica Al culture supernatants caused rapid cytolysis (<5 minutes) of isolated bovine platelets as measured by leakage of the cytoplasmic enzyme lactate dehydrogenase (ld). The platelet lytic factor had several features similar to P haemolytica leukotoxin. Like P haemolytica leukotoxin, the platelet lytic factor was produced by P haemolytica during logarithmic growth phase, was heat-labile, and was active against target cells (platelets) from ruminant species (cattle and sheep), but not from non-ruminant species (horses, pigs, and human beings). Additionally, the platelet lytic factor was neutralized with antileukotoxin rabbit serum. The amount of ld leaked by a fixed concentration of bovine platelets was proportional to the amount of toxin added at low toxic doses and became maximal at 88 ± 11% of the total platelet ld activity for high doses of toxin. When a fixed dose of toxin was used and the platelet concentration was varied, ld leakage was initially proportional to the platelet concentration, but plateaued at higher platelet concentrations. The platelet lytic factor required Ca2+ and was inhibited by addition of the Ca2+ chelator ethylene glycol-bis(β-aminoethyl ether)N,N,N′,N′-tetraacetic acid. Toxin-mediated platelet damage may be important in thrombi formation and fibrin exudation typically associated with P haemolytica pleuropneumonia of cattle.
Description of a scale for rating the clinical response of cattle poisoned by larkspur
Authors: Olsen John D. , Sisson Donald V.
Published: January 2024

Larkspur poisoning is a major cause of acute death of cattle on mountain and high plains rangelands of western United States. A nonlethal method to quantify dose response in cattle is needed to better estimate the toxicity of larkspur plants and the response of cattle to larkspur poisoning and to provide a basis for reference during studies. A numerical system of rating the clinical signs of larkspur poisoning was developed and used to describe the response of 10 Hereford cows given a repeated single daily dose of larkspur (Delphinium occidentale × barbeyi) by gavage. Larkspur poisoning resulted from a short-term cumulative effect, and a statistically significant increase in score was essentially maximal by 4 days. At the dose given, this effect did not persist for more than 4 days after cessation of dosing. Poisoning was most severe between 5 and 9 hours after dosing. Early signs of poisoning can be subtle and sometimes brief. The effect of larkspur poisoning can be exacerbated temporarily by exertion. Therefore, cattle could probably repeatedly consume an otherwise toxic daily dose, without manifesting marked signs of poisoning, if consumption decreased to a sufficient degree intermittently at 2- to 4-day intervals.
Controlled test evaluation of the benzimidazole anthelmintic VET 220-S alone or with concomitant trichlorfon treatment against naturally acquired gastrointestinal parasites in ponies
Authors: Bello Thomas R.
Published: January 2024

A controlled test was done in 30 naturally infected ponies to evaluate the antiparasitic activity of the dienbendazole analog VET 220-S given alone or with trichlorfon (tcf) by nasogastric intubation. Six ponies were nontreated; 6 were given VET 220-S (5.0 mg/kg); 6 were given tcf (40 mg/kg); 6 were given VET 220-S (2.5 mg/kg) and tcf (40 mg/kg); and 6 were given VET 220-S (5.0 mg/kg) and tcf (40 mg/kg). All ponies were euthanatized and necropsied 7 or 8 days after treatment.

Draschia megastoma, Oxyuris equi, Strongylus vulgaris, S edentatus, and small strongyles were removed efficaciously by all doses of VET 220-S. Habronema muscae and microfilariae of Onchocerca cervicalis were not removed by VET 220-S or tcf. Gasterophilus intestinalis was 97.9% removed by tcf. Pregnant mares in all groups were not adversely affected by treatment, except for 1 mare that had diarrhea after tcf treatment. Parasite eggs per gram and larval culture data agreed with necropsy data.
Serologic and blood culture survey of Trypanosoma cruzi infection in four canine populations of southern Louisiana
Authors: Barr Stephen C. , Dennis Vida A. , Klei Thomas R.
Published: January 2024

Blood culture and serologic testing were used to study the prevalence of Trypanosoma cruzi infection in a group of 85 dogs from southern Louisiana rural environment. These dogs were known to have been in contact with wild mammalian hosts of the hemoflagellate. Results were compared with blood culture and serologic test results in 103 dogs from a rural environment and with limited known wild mammalian T cruzi host contact. Serologic test results for the 188 dogs from the rural environment were compared with results for 176 dogs from an urban animal shelter and for 100 household pet dogs from an urban southern Louisiana environment. Blood culture was not performed on urban dogs. Culture results were negative in all dogs from rural environments. Serologic evidence of infection was obtained for 4 of the 85 (4.7%) dogs of rural environment with known host contact. Of 176 dogs from the animal shelter, 4 (2.3%) had high antibody titer to T cruzi, and 11 others had low titer (< 2 adjusted elisa units [aEU]). Two and 4 dogs of the housed urban and rural groups, respectively, had antibody titer to T cruzi that was < 2 aEU. Results indicate that prevalence for exposure to T cruzi antigen is higher in dogs with high potential contact with the vector and wild mammalian hosts of T cruzi, whether they are from rural or urban environment. Furthermore, results indicate that similar studies on high-risk human populations may be indicated.