bluuebunny/crossref_metadata_2025 huggingface dataset:
Clinicopathologic findings after experimental implantation of synthetic intraocular lenses in dogs
Authors: Gilger Brian C. , Whitley R. David , McLaughlin Susan A. , Wright James C. , Boosinger Timothy R.
Published: January 2024

Clinical findings indicate that canine eyes tolerate implantation of polymethylmethacrylate (pmma) intraocular lenses (iol) well, although inflammation and ocular damage attributable to the implants is not known. The use of silicone or polyhydroxyethylmethacrylate (hema) iol has not been reported in dogs. In this study, 15 conditioned, mixed-breed dogs were allotted to 3 groups: 5 received pmma iol; 5 received silicone iol; and 5 received hema iol. The iol optic was inserted into the anterior chamber of the right eye and anchored to the cornea. An identical surgical procedure was done on the left eye, except that no lens optic was inserted. Clinical examination and measurement of corneal thickness were done immediately prior to and after surgery. Aqueous humor samples were collected at the time of surgery and 28 days after surgery. Only mild and transient inflammation was observed in iol-implanted eyes. On several postoperative days, it was found that pmma iol induced significantly greater corneal thickness, aqueous flare, anterior uveal irritation, and corneal edema than did other iol. Significantly more anterior uveal irritation and increased aqueous humor protein concentration was observed with hema iol than with pmma or silicone iol. Silicone iol induced significantly less fibrin deposition than did pmma or hema iol.
Ground reaction force patterns of Dutch Warmbloods at the canter
Authors: Merkens Henk W. , Schambardt Henk C. , van Osch Geertruda J. V. M. , Hartman Wrister
Published: January 2024

Ground reaction force (grf) patterns from 20 clinically sound Dutch Warmbloods were recorded at the right fore-leading canter, and a standard horse was composed. These grf data for the standard can be used for evaluation of jumping horses.

The grf patterns were asymmetric for all 4 limbs. The leading right forelimb decelerated the body. The trailing left forelimb propelled the body and decelerated it slightly. The trailing left hind limb propelled, and the leading right hind limb contributed to deceleration and propulsion. Referred to the maximal vertical load of the leading right forelimb, the load of the trailing left forelimb was 25% more; the load of the right hind limb was slightly less, whereas the load of the left hind limb was about 80% of that value.
Characterization of newly isolated plasmids from Actinobacillus pleuropneumoniae
Authors: Ishii Hiroshi , Fukuyasu Tsuguaki , Iyobe Shizuko , Hashimoto Hajime
Published: January 2024

The genetic basis of drug-resistant strains of Actinobacillus pleuropneumoniae in Japan was studied. The A pleuropneumoniae strains AV277 and AV281 that belong to serotype 2 were resistant to streptomycin (sm) and sulfonamide (sa). Both strains had an 8.1-kilobase (kb) sm-sa plasmid that was previously classified in the H1 group. The AV177 (serotype 1) strain was resistant to sm, sa, ampicillin, and kanamycin (km), but did not have any plasmids. The AV319 and AV324 (serotype 1) strains were resistant to sm, sa, tetracycline (tc), and chloramphenicol (cp). The AV318 (serotype 12) strain was resistant to sm, sa, tc, minocycline, and cp. These 3 strains (AV319, AV324, and AV318) had a 4.3-kb sm-sa plasmid and a 5.2-kb cp plasmid. The 4.3-kb plasmid was classified in the H2 group. The AV263 (serotype 1) strain was resistant to sm, sa, km, tc, and cp. It had a 5.2-kb cp plasmid and a 6.6-kb sm-sa-km plasmid. Both plasmids did not replicate stably in Escherichia coli strains. The former 5.2-kb plasmid was mobilized in E coli strains by plasmid RP4, which belonged to incompatibility P with broad host range, but the latter 6.6-kb plasmid was not so mobilized. Three 5.2-kb cp plasmids isolated from strains AV319, AV324, and AV318, had the same restriction endonuclease pattern after digestion with Ava I and EcoRI. They coexisted with H1 group plasmids in the incompatibility test, and coexisted also with H2 group plasmids of the original A pleuropneumoniae strains. Results indicated that the 5.2-kb cp plasmids could be classified in a new incompatibility group, H3. In this study, 4 types of plasmids were isolated, but no plasmids encoded tc and minocycline resistance.
Antigenic analysis of Chlamydia pecorum and mammalian Chlamydia psittaci by use of monoclonal antibodies to the major outer membrane protein and a 56- to 64-kd protein
Authors: Kuroda-Kitagawa Yuko , Suzuki-Muramatsu Chieko , Yamaguchi Tsuyoshi , Fukushi Hideto , Hirai Katsuya
Published: January 2024

Monoclonal antibodies were prepared against 40- and 56- to 64-kd antigens of Chlamydia pecorum strain Maeda, which was isolated from a cow with pneumonia. Using the monoclonal antibodies, 5 strains of C pecorum, 25 strains of mammalian and 19 strains of avian C psittaci, 1 strain of C pneumoniae, and 3 strains of C trachomatis were analyzed for immunologic reactivity by use of the indirect immunofluorescent test. Monoclonal antibody analysis revealed immunologic relatedness between C pecorum and mammalian strains of C psittaci, which were completely differentiated from the other avian strains. Bovine strains were distinguished from ovine strains. Antigenic diversity was observed for bovine and ovine strains. Feline- and guinea pig-derived strains were shown to be immunologically different from bovine and ovine strains. Results provide the basis for typing and epidemiologic study of bovine and ovine strains of C pecorum and C psittaci.
In vitro effects of α2-adrenergic receptor stimulation on cholinergic contractions of equine distal airways
Authors: LeBlanc Patrick H. , Eberhart Susan W. , Robinson N. Edward
Published: January 2024

In horses with noninduced, reversible airway obstruction (heaves), pulmonary function is improved after sedation with the α2-adrenergic agonist xylazine. The mechanism of this effect is undetermined. Because the predominant excitatory innervation of equine airways is cholinergic, the influence of α2-adrenergic receptor stimulation on the response of isolated distal airways to cholinergic stimulation was determined. Distal bronchial segments from 22 healthy horses were suspended in isolated organ baths where their mechanical responses to various stimuli could be studied. Each tissue was incubated with one of several concentrations of clonidine, clonidine vehicle, or clonidine plus tolazoline. Then, the contractile response of the tissues to either cumulative acetylcholine (ACh) addition or cumulative electrical field stimulation (efs) was recorded. All contractile responses evoked by efs were mediated through stimulation of cholinergic airway nerves. Clonidine had no effect on the contractile response of distal airway segments to exogenous ACh. However, clonidine (at concentrations > 10-5 M) significantly (P < 0.05) diminished the contractile response of the distal airway segments to efs. This inhibitory effect of clonidine was not observed in the presence of tolazoline. Similar results were observed when the less-selective α2-adrenergic agonist xylazine was exposed to the isolated segments instead of clonidine. Because efs-but not exogenous ACh-induced contractions were inhibited, α2-adrenergic receptor stimulation apparently causes presynaptic inhibition of the cholinergic nerves innervating distal portions of the bronchi of horses.
Ultrasonographic determination, in vitro and in vivo, of canine gallbladder volume, using four volumetric formulas and stepwise regression models
Authors: Finn-Bodner Susan T. , Park Richard D. , Tyler Jeff W. , Twedt David C. , Curtis Charles R.
Published: January 2024

Twelve resected canine gallbladders (in vitro) and the gallbladder in each of 14 dogs (in vivo) were ultrasonographically examined. Gallbladder volume was calculated from ultrasonographically measured geometric dimensions, using 4 volumetric model formulas: cone, ellipse, biplanar ellipse, and prolate ellipse. Calculated volume was compared with true gallbladder volume, as measured by water displacement. All examined models for calculation of gallbladder volume were closely associated with true gallbladder volume (P < 0.005), and all models provided accurate predictions of true gallbladder volume (r2 > 0.80). Calculated volumes can be corrected mathematically by use of the regression coefficient and constant for each model. Body weight was not significantly associated with gallbladder volume in any of the models considered. Use of ultrasonography to accurately measure gallbladder volume could be combined with synthetic cholecystokinin-stimulated gallbladder emptying to provide information about biliary function and patency in icteric animals. Such information could aid the clinical decision between surgical or medical treatment. Correction of calculated volumes would not be necessary in association with induced emptying studies, because volume change is more important than absolute volume.
Acquired immunity after primary caseous lymphadenitis in sheep
Authors: Pépin Michel , Pardon Pierre , Marly José , Lantier Frédéric , Arrigo Jorge Luis
Published: January 2024

Caseous lymphadenitis (cla) caused by Corynebacterium pseudotuberculosis is a worldwide disease of sheep and goats and is characterized by development of pyogranulomas in lymph nodes and lungs. Control of this disease by vaccination remains controversial, although toxoid vaccines are now commercially available in some countries. To determine the efficacy of acquired immunity to control cla, the effect of primary infection on subsequent challenge exposure was investigated. Adult seronegative ewes were primarily inoculated with a streptomycin-sensitive strain of C pseudotuberculosis on the external part of the left ear and thereafter challenge-exposed by inoculation of the streptomycin resistant strain 19R in the right ear. This protocol indicated that primary infection with at least 107 viable bacteria induced strong protection against subsequent challenge exposure; the ewes with primary infection did not develop lesions as a result of challenge exposure, whereas immune-naive ewes developed numerous pyogranulomas in the right car, in lymph nodes draining the inoculation site, and in the lungs. However, ewes with primary infection remained carriers of the disease as a result of primary inoculation. These results offer experimental support for development of more effective vaccination to control cla in sheep and goats, and this model indicates that animals with primary infection can be used as positive controls for protection when testing a candidate vaccine against cla.
Effects of sample collection and handling on concentration of osteocalcin in equine serum
Authors: Hope Esther , Johnston Shirley D. , Hegstad Rebecca L. , Geor Raymond J. , Murphy Michael J.
Published: January 2024

A commercially available radioimmunoassay kit for measurement of human osteocalcin was validated for use in horses. For accurate measurement of equine serum osteocalcin, blood samples may be collected at a temperature between 20 and 25 C, then centrifuged within 90 minutes; serum may be stored at —20 C in plastic tubes for up to 26 weeks. Serum may be thawed and refrozen up to 5 times without significant change in measured equine serum osteocalcin concentration. Assay sensitivity was 0.16 ng/ml. Recovery of bovine osteocalcin standard added to equine serum was linear. Intra-assay coefficient of variation (X 100) for 2 equine serum pools was 6.9 (mean ± SD, 13.9 ± 1.0 ng/ml) and 7.5 (10.6 ± 0.8 ng/ml) %. Interassay coefficient of variation for 3 equine serum pools measured in 12 assays was 12.5 (16.1 ± 2.0 ng/ml), 12.7 (11.5 ± 1.5 ng/ml), and 24.6 (3.0 ± 0.7 ng/ml) %. Dilutional parallelism was documented by assaying pooled equine serum at 4 dilutions and correcting the mean result for dilution. Significant change was not observed in equine serum osteocalcin concentration for various time-of-day blood sample collections in horses housed under continuous lighting.
Abomasal interstitial fluid-to-blood concentration gradient of pepsinogen in calves with type-1 and type-2 ostertagiosis
Authors: Baker David G. , Bruss Michael L. , Gershwin Laurel J.
Published: January 2024

Pepsinogen and protein concentrations were determined in blood samples, collected from the left gastroepiploic artery and vein, and in abomasal lymph from 15 steers naturally infected with Ostertagia ostertagi and 4 uninfected steers. In steers with type-1 ostertagiosis, the concentration gradient between the mucosal interstitium and the blood alone could account for higher than normal serum pepsinogen concentrations. High interstitial pepsinogen concentrations may have resulted from increased epithelial permeability or increased pepsinogen production and secretion. However, in steers with type-2 ostertagiosis, the concentration gradient could not entirely account for the high serum pepsinogen concentrations, suggesting that capillary permeability or surface area may have been altered. Lymphatic uptake contributed pepsinogen to the blood in all infected steers.
Evaluation of the effect of alfentanil on the minimum alveolar concentration of halothane in horses
Authors: Pascoe Peter J. , Steffey Eugene P. , Black William D. , Claxton Jean M. , Jacobs James R. , Woliner Michael J.
Published: January 2024

The effect of 3 plasma concentrations of alfentanil on the minimum alveolar concentration (mac) of halothane in horses was evaluated. Five healthy geldings were anesthetized on 3 occasions, using halothane in oxygen administered through a mask. After induction of anesthesia, horses were instrumented for measurement of blood pressure, airway pressure, and end-tidal halothane concentrations. Blood samples, for measurement of pH and blood gas tensions, were taken from the facial artery. Positive pressure ventilation was begun, maintaining PaCO2, at 49.1 ± 3.3 mm of Hg and airway pressure at 20 ± 2 cm of H2O. The mac was determined in triplicate, using a supramaximal electrical stimulus of the oral mucous membranes. Alfentanil infusion was then begun, using a computer-driven infusion pump to achieve and maintain 1 of 3 plasma concentrations of alfentanil. Starting at 30 minutes after the beginning of the infusion, mac was redetermined in duplicate. Mean ± sd measured plasma alfentanil concentration during the infusions were 94.8 ± 29.0, 170.7 ± 29.2 and 390.9 ± 107.4 ng/ml. Significant changes in mac were not observed for any concentration of alfentanil. Blood pressure was increased by infusion of alfentanil and was dose-related, but heart rate did not change. Pharmacokinetic variables of alfentanil were determined after its infusion and were not significantly different among the 3 doses.
Effects of abdominal insufflation with nitrous oxide on cardiorespiratory measurements in spontaneously breathing isoflurane-anesthetized dogs
Authors: Gross M. E. , Jones Brent D. , Bergstresser D. R. , Rosenhauer R. R.
Published: January 2024

Cardiorespiratory effects of abdominal insufflation were evaluated in 8 dogs during isoflurane anesthesia. Each dog was studied 3 times, in 1 of the following orders of insufflation pressures: 10-20-30, 20-30-10, 30-20-10, 10-30-20, 20-10-30, and 30-10-20 mm of Hg. Anesthesia was induced by use of a mask, dogs were intubated, and anesthesia was maintained by isoflurane in 100% oxygen. After instrumentation, baseline values were recorded (time 0), and the abdomen was insufflated with nitrous oxide. Data were recorded at 5, 10, 15, 20, 25, and 30 minutes after insufflation. The abdomen was then desufflated, with recording of data continuing at 35 and 40 minutes. Mean arterial pressure increased at 5 minutes during 20 mm of Hg insufflation pressure, and from 20 to 30 minutes during 30 mm of Hg pressure. Tidal volume decreased from 5 to 30 minutes during 10 and 20 mm of Hg pressures, and from 5 to 40 minutes during 30 mm of Hg pressure. Minute ventilation decreased at 10 and 20 minutes during 20 mm of Hg pressure. End-tidal CO2 concentration increased from 5 to 30 minutes during 20 and 30 mm of Hg pressure. The PaCO2 decreased at 40 minutes during 10 mm of Hg pressure, at 30 minutes during 20 mm of Hg pressure, and from 10 to 40 minutes during 30 mm of Hg pressure. Values for pH decreased from 10 to 30 minutes during 20 and 30 mm of Hg pressures. The PaO2 decreased from 20 to 40 minutes during 10 mm of Hg pressure, at 30 minutes during 20 mm of Hg pressure, and from 10 to 40 minutes during 30 mm of Hg pressure. Percentage decrease in tidal volume was greater at 5 and 15 minutes with 30 mm of Hg pressure. Differences in percentage increase in end tidal CO2 concentration were observed among the 3 pressures from 5 to 30 minutes. Although significant, these changes do not preclude use of laparoscopy if insufflation pressure > 20 mm of Hg is avoided.
Inhibition of myelopoiesis by conditioned medium from cultured canine thymic cells exposed to estrogen
Authors: Farris Georgia M. , Benjamin Stephen A.
Published: January 2024

Therapeutic doses of estrogens can cause fatal bone marrow damage in dogs, which are more sensitive than other species to these myelotoxic effects. Investigations with mice indicated that estrogens did not directly damage the bone marrow progenitor cells, but that the thymus responded to estrogen by producing a factor that inhibited bone marrow granulocyte-macrophage progenitor cell replication. A similar estrogen-induced myelopoiesis-inhibitory factor was produced by canine thymic cells in culture. This canine factor was more inhibitory to myelopiesis than was the murine factor. Canine bone marrow progenitor cell growth was not significantly inhibited by direct estrogen treatment, which supported evidence for indirect thymus mediation of estrogen toxicity in vivo. Estrogen receptors were detected in canine nonlymphoid thymic cells by use of immunocytochemical staining. These findings indicate that the high estrogen sensitivity of dogs may relate to greater estrogen-induced myelopoiesis-inhibition by the thymus.
Serum interleukin-6 concentrations in endotoxin-infused neonatal foals
Authors: Robinson Julie A. , Allen Gary K. , Green Eleanor M. , Garner Harold E. , Loch Wayne E. , Walsh Donald M.
Published: January 2024

Serum interleukin-6 (il-6) concentration was measured in 11 colostrum-fed (cf) and 8 colostrum-deprived (cd) 2- to 3-day-old foals after foals were infused with lipopolysaccharide (lps; Escherichia coli O55:B5 endotoxin, 0.5 µ.g/kg of body weight in sterile saline [0.9% NaCl] solution). Four cf and 2 cd foals were given saline solution alone. Serum il-6 concentration was estimated by use of an in vitro proliferative bioassay, using the IL-6 dependent B.13.29 clone 9 cells. Interleukin-6 concentration increased in all lps-infused foals, and geometric mean serum il- 6 concentration was significantly higher in cf than cd foals 30 and 90 minutes after infusion. Both lps- infused groups had multiple spikes of mean il-6 concentration that peaked at 120 minutes in cf foals and 150 minutes in cd foals. Results indicated that il-6 is produced in neonatal foals in response to lps infusion. Furthermore, colostrum deprivation resulted in longer times to peak mean serum il-6 concentration and tended to reduce serum il-6 concentration in neonatal foals.
Isolation of Mycobacterium paratuberculosis from mononuclear cells in tissues, blood, and mammary glands of cows with advanced paratuberculosis
Authors: Koenig Gerard J. , Hoffsis Glen F , Shulaw William P. , Bech-Nielsen Steen , Rings D. Michael , St-Jean Guy
Published: January 2024

Seven mature dairy cows from 6 herds were obtained with history, clinical signs of disease, and laboratory findings suggestive of advanced paratuberculosis. A surgically implanted collection chamber was used to obtain peripheral tissue fluid. Blood, mammary gland flush fluid, and collection chamber flush fluid (ccff) samples were obtained 6 times over a 2-week period from each cow. Mononuclear cell-rich portions of these fluids obtained by gradient centrifugation were submitted for bacteriologic culture of Mycobacterium paratuberculosis and for total and differential cell counts.

Bacteriologic culture of feces for M paratuberculosis and complete necropsy performed on each cow at the conclusion of the study confirmed the diagnosis of paratuberculosis. Numbers of tissue macrophages obtained from ccff samples were lower than expected. Mean (± SD) differential count of tissue macrophages collected from ccff was 65.57 (± 23.39). Mean calculated tissue macrophages (total cell count × differential count) collected from ccff samples was 623.1 (±784.55) cells/μl. Mycobacterium paratuberculosis was isolated from 1 of 42 (2.4%) collections of mononuclear cell-rich portions of plasma and from 2 of 42 (4.8%) ccff samples. Mycobacterium paratuberculosis was not isolated from any collections of mammary gland flush fluid. The collection and processing techniques used in this study did not enhance detection of M paratuberculosis infection in cows with advanced paratuberculosis, beyond that of ileocecal lymph node biopsy or fecal culture.
Effects of hylan on amphotericin-induced carpal lameness in equids
Authors: Peloso J. G. , Stick J. A , Caron J. P. , Peloso P. M. , Soutas-Little R. WC
Published: January 2024

In this double-blind study, the effectiveness of and dose response to intra-articular administration of modified hyaluronan (hylan) was determined in an equine carpal lameness model over a 23-day period, using a computerized three-dimensional motion analysis system, synovial fluid variables, and synovial histologic examination.

In 24 clinically sound horses, baseline motion data was acquired from horses trotting at 4 m/s on a high-speed treadmill. Then, to induce lameness, 25 mg of amphotericin B in 5 ml of sterile water was injected into the left middle carpal joint of each horse every other day for 3 treatments. Phenybutazone (2.2 mg/kg of body weight, PO, once) and butorphanol tartrate (0.1 mg/kg, IM, q 6 h, for 36 hours) were used to control signs of discomfort. Horses were assigned at random to 4 equal groups and received intracarpal administration of either 1, 2, 4 ml of hylan (8 mg/ml), or 2 ml of balanced electrolyte solution (control).

Intracarpal administration of amphotericin B caused significant (P ≤ 0.01) increase in subjective lameness grades over the 2-week evaluation period, and hylan administration did not significantly (P ≤ 0.01) change the subjective lameness grade. Lameness induction caused significant (P ≤ 0.01) decrease in head and withers excursions during the lame forelimb support phase and significant (P ≤ 0.05) increase in head and withers excursions during the sound forelimb support phase. Synovitis induction was further characterized by significant (P ≤ 0.05) increases in total wbc, polymorphonuclear, and large and small mononuclear cell numbers, and synovial fluid total protein concentrations. Also, subjective scores for synovial sections were significantly (P ≤ 0.05) different from baseline values, but hylan treatment at the 1-, 2-, or 4-ml dose did not significantly (P ≤ 0.05) alter these variables, compared with baseline values or values in control horses. Hyaluronan concentrations were not altered by induction of synovitis or hylan treatment.

Although clinical use of hyaluronan for treatment of traumatic joint disease in horses is well accepted, the beneficial effect of hylan was not detectable in this study. Further studies are required to more fully characterize the possible beneficial effects of hyaluronan-based products for treatment of joint disease in equids.
Endogenous creatinine clearance measurement of glomerular filtration rate in dogs
Authors: Finco Delmar R. , Tabaru Hideki , Brown Scott A. , Barsanti Jeanne A.
Published: January 2024

Renal clearance procedures were performed on adult mixed-breed dogs with a wide range of renal function. Endogenous creatinine clearance was computed after analyzing plasma and urine for creatinine by use of 2 methods, PAP and kinetic Jaffe. For 20-minute clearance procedures, [14C]inulin clearance was measured simultaneously with endogenous creatinine clearance.

For 111 twenty-minute clearance procedures performed on 24 dogs, [14C]inulin clearance was highly correlated with creatinine clearance for both methods of creatinine analysis (R2 = 0.979 for [14C]inulin-PAP; R2 = 0.943 for [14C]inulin-Jaffe). The absolute values for PAP and [14C]inulin clearance were nearly the same (PAP-to-[14C]inulin clearance ratio = 1.03 ± 0.08), but those for Jaffe clearance were substantially less than those for [14C]inulin clearance (Jaffe-to-[14C]inulin clearance ratio = 0.88 ± 0.10).

The Jaffe-to-[14C]inulin clearance ratio was inversely correlated with degree of renal function (R2= 0.464), whereas the PAP-to-[14C]inulin clearance ratio was not correlated with degree of renal function (R2 = 0.060). Thus, Jaffe-determined creatinine clearance varied, in relation to [14C]inulin clearance, depending on degree of renal function.

In 4 clinically normal dogs, 20-minute and 24-hour sample collections analyzed by use of the PAP method gave clearance values significantly greater, for both periods, than did Jaffe analyses. The PAP-determined creatinine clearance values were less than, but not significantly different from 20-minute exogenous creatinine clearance values determined 10 days after 24-hour collections.

For 20-minute and 24-hour collections, the difference in clearance values between the PAP and Jaffe methods was attributable mostly to lower plasma creatinine values for the PAP method (mean ± SEM, plasma PAP-to-Jaffe ratio = 0.798 ± 0.053). However, urine creatinine values also were less by use of the PAP method (urine PAP-to-Jaffe ratio = 0.943 ± 0.103).

We conclude that PAP-determined creatinine clearance reliably measured glomerular filtration rate during 20-minute collections, and probably during 24-hour collections as well. By contrast, Jaffe-determined creatinine clearance underestimated glomerular filtration rate by a variable amount.
Clinical and endoscopic study to estimate the incidence of distal respiratory tract infection in Thoroughbred foals on Ontario breeding farms
Authors: Hoffman Andrew M. , Viel Laurent , Juniper Elizabeth , Prescott John F.
Published: January 2024

Respiratory tract infections are prevalent in foals, yet the frequency with which the distal airways are affected in clinical episodes of respiratory tract disease has not been evaluated to our knowledge. The objective of the study was to determine the incidence of distal respiratory tract infection (drti) in foals on a sample of Thoroughbred breeding farms (n = 10) in Ontario. In a pilot study, clinical criteria commonly used to select foals for antimicrobial treatment (detection of abnormal lung sounds, plus nasal discharge, cough, fever, tachypnea, and/or lethargy) were found to segregate foals with and without endoscopically confirmed drti. Mucopurulent exudate and bronchial erythema were observed more frequently (P < 0.005), bronchial lavage total cell count and neutrophil concentration were significantly (P < 0.005) higher, and intracellular cocci were recovered significantly (P < 0.01) more often from bronchial lavage samples of affected foals (n = 8) than of controls (n = 8). These clinical criteria were used to identify cases in a cohort of Thoroughbred foals (n = 219) from May 1 to October 30, 1991. Case morbidity adjusted for clustering was 82 ± 5% (95% confidence limits, 72 to 92%). Most (74%) episodes of clinical drti were detected in July and August, and equal numbers were detected before (53%) and after (47%) weaning of foals. Of 178 cases, 66 (48%) were selected at random for endoscopy and bronchial lavage. Grade-II pharyngeal lymphoid hyperplasia was observed commonly (60% of foals); auditory tube diverticulum (guttural pouch) discharge was observed in 18 of 86 (21%) foals, and guttural pouch infection was confirmed in 6 of 7 foals examined endoscopically. Endoscopically confirmed drti, defined as visual detection of bronchial exudate with microscopic detection of intracellular cocci and markedly high neutrophil count in bronchial lavage samples, was confirmed in 75 of 86 (87%) cases tested. These data indicate that drti might be reliably diagnosed by auscultation during a simple rebreathing exercise. The syndrome of drti was extremely common in Thoroughbred foals, characterized by marked inflammation of visible airways and cytologic evidence of bacterial infection. Risk factors for clinical (undifferentiated) drti were not identified in this study.
Association of microbiologic flora with clinical, endoscopic, and pulmonary cytologic findings in foals with distal respiratory tract infection
Authors: Hoffman Andrew M. , Viel Laurent , Prescott John F. , Rosendal Soren , Thorsen Jan
Published: January 2024

Undifferentiated distal respiratory tract disease (nasal discharge, cough, pneumonia) in foals (1 to 8 months old) is a burdensome economic problem on breeding farms; yet, the infective agents associated with these episodes have not been well described. Possible causes of these episodes of illness were investigated by culturing specimens of proximal and distal airways of clinically diseased foals (n = 101), prior to any treatment, for aerobic and anaerobic bacteria and viruses (rhinoviruses, equine arteritis virus, equine herpesvirus subtype 1 [ehv-1], influenza virus, and adenovirus). Pairs of sera (n = 47) were examined for antibodies to influenza A virus, equine subtypes 1 and 2, ehv-1, and adenovirus antigens, and sera obtained from foals during acute infection were examined for antibodies (by agar gel immunodiffusion [agid]) to equi factor antigens of Rhodococcus equi. Viruses were not isolated from the proximal (swab) or distal (bronchial lavage) airway specimens in foals, and only 2 of 47 randomly selected foals seroconverted to ehv-1. Serotiters to the other viruses were low and frequently decreasing between samples, which was compatible with maternally derived antibody. Streptococcus zooepidemicus was the predominant isolate from bronchial lavage specimens (88/101 cases), accompanied by α-hemolytic streptococci (8 cases), Bordetella bronchiseptica (13 cases), Staphylococcus epidermidis (9 cases), and other organisms in lesser frequency. Only Str zooepidemicus was recovered significantly (P < 0.05) more often in cases than in controls. The agid test was found useful to detect foals with presumed exposure to R equi, but positive tests results did not correspond well with bacterial culture results; positive agid results were recorded in 34% of culturenegative foals. However, foals from which R equi was isolated were distinctive from the other foals on the basis of fever (> 39 C), lack of nasal discharge, blood neutrophilia, and decreased percentage of neutrophils in bronchial lavage fluid samples. Isolation of Str zooepidemicus was significantly (P < 0.01) associated with increasing neutrophil percentage in bronchial lavage fluid. In conclusion, the pathogenic roles of Str zooepidemicus and R equi were established in this group of foals with distal respiratory tract infections by use of clinical, endoscopic, hematologic, and cytologic methods. There was no evidence of a viral cause for these infections, indicating that manifestations of distal respiratory tract infection are attributable to bacterial infection causing inflammation of the airways. Further studies are warranted to pursue more-sensitive methods for detection of viral antigen or antibody in undifferentiated distal respiratory tract disease episodes in foals.
Neuropeptidergic innervation of equine synovial joints
Authors: Bowker Robert M. , Abhold Raymond H. , Caron John P. , Sonea Ioana M. , Vex Kelly B. , Kotyk Rebecca
Published: January 2024

Immunocytochemical analysis of equine synovial membranes revealed presence of several neuropeptides, including substance P (sp), neurokinin A, and neuropeptide Y, in nerves of the radiocarpal, middle carpal, and metacarpophalangeal (fetlock) joints. Within the subsynovium, these neuropeptides were located perivascularly, whereas in the fronds, only neuropeptide Y was restricted to the vessels of the synovial membrane. Only sp and neurokinin A were found in the intimal layer. The intimal layer of the metacarpophalangeal joint contained more sp-immunoreactive fibers than were observed in the intimal layer of the radiocarpal joint. Substance P also was detected in the synovial fluid from all 3 joints, but mean ± sd concentrations were significantly different only between the middle carpal joint (37.56 ± 5.48 fmol/ml; n = 6) and the metacarpophalangeal joint (55.80 ± 8.33 fmol/ml; n = 5) and between the middle carpal joint and the radiocarpal joint (52.43 ± 14.60 fmol/ml; n = 7).
Sensory receptors in the equine foot
Authors: Bowker R. M. , Brewer A. M. , Vex K. B. , Guida L. A. , Linder K. E. , Sonea I. M. , Stinson A.W.
Published: January 2024

Two types of sensory receptors were located in the equine foot, using anatomic techniques. Histologic examination of stained hoof sections revealed lamellated corpuscles in the hoof dermis, which had many of the morphologic characteristics of Pacinian corpuscles. These sensory receptors were restricted to the palmar (caudal) aspects of the solar dermis of the heel. A second type of receptor was detected by use of immunocytochemistry, indicating apparently naked nerve endings containing the neuropeptide calcitonin gene-related peptide-like immunoreactivity in skin, solar dermal tubules, and the digital cushion. This peptide is an example of a sensory neurotransmitter contained in dorsal root ganglion cells and is believed to exist only in unmyelinated sensory nerve fibers. These 2 morphologic structures may be used for detection of sensory stimuli, such as pressure (or vibratory senses) and pain, respectively, in horses during various locomotory gaits.
Humoral immune responses in cats with dermatophytosis
Authors: Sparkes Andrew Howard , Stokes Christopher Robin , Gruffydd-Jones Timothy John
Published: January 2024

The IgG and IgM classes of antibodies to a watersoluble antigen preparation derived from Microsporum canis were determined by elisa in the sera of 79 cats with dermatophytosis confirmed by results of fungal culture, and of 46 specific-pathogen-free-derived, barrier-maintained cats with no previous exposure to dermatophytes. Of the 79 cats with dermatophytosis, the species isolated were: M canis from 72, M gypseum from 6, and Trichophyton mentagrophytes from 1.

Concentrations of soluble M canis antigen-specific IgG and IgM were significantly (P < 0.05) higher in the cats with dermatophytosis than in the control cats. The IgG concentration was ≥ 2.0 elisa units/ml in 71% of the cats with dermatophytosis and in 9% of the control cats, whereas IgM concentration was ≥ 4.0 elisa units/ml in 38% of the cats with dermatophytosis and in 11% of control cats. There was no significant difference in either IgG or IgM values between the cats with M canis infection and those with other non-M canis dermatophyte infections.
Pharmacokinetics of metronidazole after rectal administration in horses
Authors: Garber Jenifer L. , Brown Murray P. , Gronwall Ronald R. , Merritt Kelly
Published: January 2024

Five healthy adult mares and 1 gelding were given a single dose (15 mg/kg of body weight) of metronidazole per rectum. After manual evacuation of feces from the rectum, a suspension of crushed tablets and water (40 ml) was administered via a 28-F catheter advanced 30 cm into the rectum. Blood samples were obtained by jugular venipuncture, and metronidazole concentration was measured serially for the 14 hours after drug administration. Mean serum concentration of metronidazole peaked at 4.5 μg/ml, 0.83 hour after administration, and decreased to 0.38 μg/ml, 14 hours after administration. Mean elimination rate constant was 0.23/h, and the harmonic mean elimination half-life was 3.04 hours. Further study is necessary to determine a therapeutic dose regimen for metronidazole administered per rectum.
Effect of furosemide on physiologic variables in exercising horses
Authors: Harkins J. D. , Hackett R. P. , Ducharme N. G.
Published: January 2024

Twelve horses (6 Standardbreds and 6 Thoroughbreds) received im injections of furosemide (250 mg) or physiologic saline solution and performed standard exercise tests, to assess the effects of furosemide and breed on blood gas values, pcv, plasma lactate concentration, and heart rate during exercise. After furosemide administration, arterial and venous blood pH values were significantly (P < 0.05) increased. Partial pressures of O2 and CO2 in arterial blood and of CO2 in venous blood (Pao2, PaCO2, and PvCO2, respectively) were unaffected by furosemide treatment, whereas venous partial pressures of O2 (Pvo2) were significantly (P < 0.05) less during exercise after furosemide treatment, suggesting an increase in oxygen uptake by the exercising muscles or a change in cardiac output. A significant (P < 0.05) difference was found between Thoroughbred and Standardbred values for arterial and venous pH, PaO2, PaCO2, plasma lactate concentration, and heart rate, suggesting that Standardbreds exercised at a relatively higher work rate than did Thoroughbreds.
Effect of dietary sodium intake on glomerular filtration rate in partially nephrectomized dogs
Authors: Greco Deborah S. , Lees George E. , Dzendzel Gerald S. , Komkov Andrea , Carter Alice B.
Published: January 2024

Exogenous creatinine clearance rate was determined in 8 partially (approx 75%) nephrectomized dogs fed 2 concentrations of dietary sodium, beginning 9 weeks after partial nephrectomy was performed. In a double crossover design, dogs were then fed low-sodium diet (0.18% sodium on a dry-weight basis) or high-sodium diet (1.3% sodium on a dry-weight basis) in 2 sequences (l/h/l or h/l/h) for 3 consecutive 4-week observation periods. Glomerular filtration rate (gfr) was measured by exogenous creatinine clearance before and after partial nephrectomy, and every 2 weeks during the experimental diet periods. Initial mean ± sd gfr (3.76 ± 0.78 ml/min/kg of body weight) decreased precipitously after nephrectomy (1.25 ± 0.45 ml/min/kg); however, during the postnephrectomy and experimental diet periods, gfr gradually increased in all dogs to nearly half the prenephrectomy values (1.87 ± 0.22 ml/min/kg). Significant differences ingfr were not observed when dogs were fed the l/h/l or the h/l/h sequence. Therefore, it was concluded that abrupt change from high dietary sodium (1.3%) to restricted dietary sodium (0.18%), or vice versa, does not cause deterioration of renal function in dogs with moderate renal impairment. However, caution should be used in extrapolating these findings to dogs with clinically evident (azotemia, isosthenuria) renal failure.
Efficacy dosage titration of lufenuron against developmental stages of fleas (Ctenocephalides felis felis) in cats
Authors: Blagbum Byron L. , Vaughan Joy L. , Lindsay David S. , Tebbitt Guy L.
Published: January 2024

Thirty-two mixed-breed male and female cats were blocked by sex, arranged by body weight from greatest to least, and allocated to 4 groups of 8 (4 male, 4 female) cats, using random numbers. Cats in each of 3 groups were treated orally with a 7% suspension formulation of lufenuron at dosage of 15, 30, or 45 mg/kg of body weight. Cats in the fourth group were treated orally with an excipient suspension without lufenuron. Cats were infested with newly emerged, unfed cat fleas (Ctenocephalides felis felis) on days - 7 and — 3 before treatment and at approximately weekly intervals after treatment. Flea eggs were collected from beneath each cat on selected days before and after treatment and placed in an artificial rearing medium. Flea eggs and medium were kept for 35 days in an insectary to determine effects of lufenuron or excipient suspension on emergence of adults of the F1 generation. Lufenuron was 100% effective in inhibiting development of C felis at all dosages for 11 days after treatment. Thereafter, efficacy exceeded 92% in all dosages groups. On day 32, when the study was terminated, efficacy for each of the dosage groups was: 15 mg/kg, 95.2%; 30 mg/ kg, 98.2%; and 45 mg/kg, 99.6%. Adverse reactions or side effects were not observed in cats, regardless of treatment dosage.
Bovine mammary teat and ductal epithelial cell cultures
Authors: Cifrian Eduardo , Guidry Albert J. , O'Brien Celia N. , Keys John E. , Marquardt Warren W.
Published: January 2024

Bovine mammary epithelial cells from teat and ductal tissue were isolated at necropsy and were grown in culture. Cells were characterized by the presence of cytokeratin filaments, cell morphologic features, synthesis of milk proteins, esterase activity, dna content, and growth patterns on polystyrene, fibronectin, laminin, collagen, and reconstituted basement membrane from the Engelbreth-Holm-Swarm murine sarcoma. Cultured teat and ductal cells stained intensely for cytokeratin and had similar morphologic features. Both cell types synthesized α-casein, β-casein, α-lactalbumin, β-lactoglobulin, and lactoferrin to variable degrees. Cell type and culture conditions did not affect the dna content of the cells, as indicated by similar amounts of dna in G0G1 and G2M phases of the mitotic cycle in cultured cells and in cells from freshly isolated mammary explants. Cells cultured on polystyrene, fibronectin, laminin, and collagen formed pavement-like cell monolayers suitable for cytotoxicity and bacterial adherence studies. Cells cultured on the reconstituted basement membrane from the Engelbreth-Holm-Swarm murine sarcoma formed three-dimensional structures closely resembling lactiferous ducts and alveoli, which could be used for studying lactogenesis and galactopoiesis. Freshly isolated cells and cultured cells were stored at -70 C or in liquid nitrogen. The latter storage method affected the cells less than did freezing at -70 C.
Comparative use of various mydriatic drugs in kestrels (Falco tinnunculus)
Authors: Mikaelian Igor , Paillet Isabelle , Williams David
Published: January 2024

The mydriatic effect of 3 curare-like neuromuscular blocking agents was tested in European kestrels (Falco tinnunculus) after topical application. Alcuronium chloride (5 mg/ml) was found to be effective at a dose of 1 drop (20 drops = 1 ml) administered twice at a 15-minute interval. Mydriasis was achieved at t = 26 ± 11 minutes, maximal effect was reached at t = 60 ± 39 minutes, and sufficient mydriasis ended at t = 364 ± 134 minutes. Nevertheless, side effects, including temporary full paralysis in 1 bird, indicated that this drug should not be used. Pancuronium bromide (2 mg/ml) had an inconsistent effect on each bird at a dose of 2 drops administered twice at 15-minute intervals, and total mydriasis was not reached in 5 of 8 birds. Mydriasis was achieved at t = 34 ± 11 minutes, maximal effect was reduced and reached at t = 43 ± 13 minutes, and sufficient mydriasis ended at t = 90 ± 39 minutes. Vecuronium bromide (4 mg/ml) was administered at a dose of 2 drops, 3 times, at 15-minute intervals. Mydriasis was achieved at t = 23 ± 8 minutes, maximal effect was reached at t = 65 ± 12 minutes, and sufficient mydriasis ended at t = 253 ± 65 minutes. Side effects were not detected. Vecuronium bromide should be used in raptorial birds whenever retinal examination requires fundoscopy.
Effective treatment with dihydrostreptomycin of naturally infected cows shedding Leptospira interrogans serovar hardjo subtype hbardjobovis
Authors: Gerritsen Marijke J. , Koopmans Metje J. , Dekker Toos C. E. M. , Jong Mart C. M. De , Moerman Arent , Olyhoek Tom
Published: January 2024

The efficacy of dihydrostreptomycin in stopping the shedding of Leptospira hardjo subtype hardjobovis was studied in naturally infected cows. Blood and urine samples were collected from dairy cows kept on a farm where the farmer had contracted L hardjobovis infection. A microscopic agglutination test and an ELISA were used to determine specific antibody responses in serum. Polymerase chain reaction was used to detect bacterial shedding in urine. On the first sample collection date, 6 cows were seropositive, and 3 of those shed leptospires in the urine. These 3 cows were treated once with 25 mg of dihydrostreptomycin/ kg of body weight. Within 1 week, the 3 cows stopped shedding leptospires. Six weeks later, 8 more lactating cows were found to be shedding leptospires. These cows were also treated once with dihydrostreptomycin, and they too stopped shedding leptospires within 1 week. From then on, the whole herd was examined weekly for a period of 2 months, and all cows Leptospira-positive by polymerase chain reaction were treated once with dihydrostreptomycin. Again, all cows stopped shedding leptospires in the urine within 1 week after treatment with dihydrostreptomycin. After a single treatment of the whole herd at the same time, new infections were not seen.
Use of polymerase chain reaction to detect porcine parvovirus associated with swine embryos
Authors: Gradil C. M. , Harding M. J. , Lewis K.
Published: January 2024

The role of porcine parvovirus (ppv) in inducing reproductive failure in swine has been extensively documented. However, information is not available as to the risk of ppv transmission by embryo transfer. Using the polymerase chain reaction (pcr) technique, ppv-specific DNA was detected in association with 4-day-old porcine embryos incubated in vitro in the presence of NADL-8 strain of ppv, despite attempts to rid the embryos of virus by either washing or treatment with pronase or trypsin. The presence of ppv in embryos collected from acutely infected swine was not detected by pcr, although ppv DNA was detected in the proximal portion of the reproductive tract during the early stages of infection. Viral specific nucleic acid was not detected in embryos transferred from infected donors to seronegative recipients and retrieved and assayed on the 15th and 32nd days of gestation. Results of the use of pcr to detect ppv associated with swine female reproductive tract and embryos ascribe minimal risk to the transmission of ppv to seronegative recipients through embryo transfer.
Antibody binding of circulating ergot alkaloids in cattle grazing tall fescue
Authors: Hill Nicholas Scott , Thompson Frederick Nimrod , Dawe Donald Louis , Stuedemann John Alfred
Published: January 2024

Direct evidence linking alkaloids found in endophyte-infected tall fescue forage with the livestock disorder known as fescue toxicosis is lacking. Physiologic effects of fescue toxicosis include reduced serum prolactin concentration in cattle. A monoclonal antibody specific to the lysergic moiety of ergot alkaloids was developed in mice after creating an immunogen by linking lysergol to human serum albumin. The antibody was specific to the lysergic moiety and, therefore, it cross-reacted with ergot alkaloids, lysergic acid, and lysergol. The antibody did not cross-react with alkaloid derivatives that had bromated or hydrogenated lysergic ring moieties. Fescue toxicosis conditions were elicited in yearling Angus steers by permitting them to graze endophyte-infected tall fescue containing > 650 μg/kg of ergovaline for 60 days. Passive immunization of steers by infusion of the monoclonal antibody increased serum prolactin concentration by 7 ng/ml, beginning immediately after infusion. Control steers did not respond to treatment with bovine serum albumin. Active immunization of yearling Angus heifers with immunogens containing lysergol or ergonovine linked to human serum albumin resulted in an antibody response.