bluuebunny/crossref_metadata_2025 huggingface dataset:
Blood cell deformability in horses with intestinal colic
Authors: Seahorn Thomas L. , Gaunt Stephen D. , Berry Cindy
Published: January 2024

Hematologic and rheologic variables were examined in a group of 13 horses with intestinal colic and a control group of 6 horses. All horses had been recently transported to the veterinary teaching hospital, and blood samples were obtained during initial examination. There were no significant differences in blood neutrophil count or plasma fibrinogen concentration between the groups, and PCV was significantly increased in horses with intestinal colic. Cell filterability was measured by passing uniform concentrations of blood, erythrocytes, and neutrophils through micropore filters. There were no significant differences between the control and intestinal colic groups in filterability of erythrocytes. Significant (P < 0.05) prolongation in filterability of blood and neutrophils was observed in the group of horses with intestinal colic, compared with the control group. This neutrophil change, indicative of decreased neutrophil deformability, corresponded with severity of the illness. Horses that failed to survive the intestinal. colic episode had significantly (P < 0.05) prolonged blood and neutrophil filterability, compared with horses that survived intestinal colic. These findings indicate that deformability of neutrophils decreases in horses with intestinal colic, possibly a result of endotoxin-induced activation. This change can further impede microvascular blood flow that is altered in association with intestinal ischemia.
Hemodynamic and analgesic effects of propofol infusion in medetomidine-premedicated dogs
Authors: Thurmon John C. , Ko Jeff C. H. , Benson G. John , Tranquilli William J. , Olson William A.
Published: January 2024

Hemodynamic and analgesic effects of medetomidine (30 μg/kg of body weight, im), atropine (0.044 mg/kg, im), and propofol (2 mg/kg, IV, as a bolus, and 165 μg/kg/min, Iv, for 60 minutes, as an infusion) were evaluated in 6 healthy adult Beagles. Catheters were placed while the dogs were anesthetized with isoflurane in oxygen. Administration of isoflurane was then discontinued, and dogs were allowed to breath oxygen until end-tidal isoflurane concentration was ≤ 0.5%. At this time, baseline measurements were recorded and medetomidine and atropine were administered. Ten minutes later, the bolus of propofol was given and the infusion was begun. Analgesia was evaluated with a tail clamp test and by use of a direct-current nerve stimulator. Sinoatrial and atrioventricular blockade developed in all 6 dogs within 2 minutes of administration of medetomidine and atropine, but disappeared within 10 minutes. Apnea did not develop after administration of propofol. Analgesia was strong and consistent throughout the entire 60-minute period of propofol infusion. Medetomidine significantly (P < 0.05) increased systemic vascular resistance and decreased cardiac output, compared with baseline values. Propofol infusion appeared to alleviate medetomidine induced vasoconstriction. Recovery was smooth and uncomplicated. All dogs were able to walk normally at a mean time (± sem) of 88.2 ± 20.6 minutes after termination of propofol infusion. It was concluded that medetomidine, atropine, and propofol, as given in the present study, is a safe combination of anesthetic drugs for use in healthy Beagles.
Repeatability and normal values for measurement of pharyngeal and tracheal pressures in exercising horses
Authors: Ducharme Norm G. , Hackett Richard P. , Ainsworth Dorothy M. , Erb Hollis N. , Shannon Kevin J.
Published: January 2024

Repeatability of measurements of peak and mean tracheal and pharyngeal pressures in exercising horses was determined. Five athletically fit horses were subjected to repeated (n = 5) standardized exercise trials. Static pressures in the trachea, nasopharynx, and mask were determined. At least 96% of all mean pressure measurements were within 5 cm of H2O of the mean value for any horse. Peak pressure measurements were less repeatable, but at least 96% of all measurements were within 10 cm of H2O of the mean peak measurements for any horse. In 10 horses galloping at 14 m/s, the 95% confidence interval for peak treacheal and pharyngeal inspiratory pressures ranged from —40 to —50 cm of H2O and —20 to — 26 cm of H2O, respectively. During expiration, the 95% confidence interval for peak tracheal and pharyngeal pressure at the same speed ranged from 15 to 28 cm of H2O and 10 to 24 cm of H2O respectively. During inspiration, horses with induced laryngeal hemiplegia had static pressure measurements generally outside that range. We conclude that determination of tracheal and pharyngeal pressures is a potentially useful adjunct for assessment of the proximal portion of the respiratory tract.
Early insulin response to an intravenous glucose tolerance test in horses
Authors: Giraudet A. , Hinchcliff K. W. , Kohn C. W. , McKeever K. H.
Published: January 2024

Plasma insulin concentration of many species has a characteristic early or acute-phase response in the minutes after IV administration of glucose. However, the plasma insulin response of horses soon after the IV administration of glucose has not been examined, whereas the more prolonged response has been evaluated. We examined the plasma insulin and glucose concentration responses of adult mares during the 30 minutes after rapid IV administration of glucose (0.33 g/kg of body weight). Plasma glucose concentration peaked at 664 ± 54 mg/dl within 1 minute of cessation of glucose administration, whereas insulin concentration peaked at 326 ± 24 pmol/L at 2 minutes after the end of glucose administration. Thus, these mares had an acute insulin response, consistent with that observed in other species, including dogs, human beings, and cattle.
Pulmonary intravascular macrophages in horses and ponies
Authors: Longworth Kim E. , Jarvis Kathleen A. , Tyler Walter S. , Steffey Eugene P. , Staub Norman C.
Published: January 2024

Seven horses (4 anesthetized and 3 awake) and 2 ponies (anesthetized) were studied to evaluate the high sensitivity of the pulmonary circulation of the horse to various blood-borne particles, and to establish the presence of intravascular macrophages in the lung. Pulmonary and systemic pressures and cardiac output before and during particle injection were measured in some animals. An anesthetized foal had a large increase in pulmonary arterial pressure (32 and 34 mm of Hg) within 1 minute of IV administration of small test doses of radioactively labeled liposomes (2.5 μmol/kg of body weight) or a 1% suspension of blue pigment (0.3 ml/kg), respectively. Quantitative real-time gamma camera imaging of the foal revealed high retention of the labeled liposomes during the first pass through the lungs; retention persisted throughout the experiment. Postmortem analysis revealed 55 and 47% lung retention of liposomes and blue pigment, respectively. The 2 anesthetized ponies had increased pulmonary artery pressure of 34 ± 7 mm of Hg, decreased cardiac output, and 42% lung retention after administration of 1% blue pigment (0.2 ml/kg), whereas 3 awake horses had increased pressure of 28 ± 9 mm of Hg after 1.8 × 108 (1.8-μm-diameter) latex microspheres/kg. None of the injected particles caused vascular obstruction, and they do not cause pulmonary vascular reactivity in species that lack pulmonary intravascular macrophages. Finally, 3 horses (1 anesthetized and 2 awake) were infused Iv with small doses of the blue pigment, and their lungs were perfusion-fixed to identify specific labeling of the pulmonary intravascular macrophages. These cells were fully differentiated macrophages, contained blue pigment in phagocytes, and were tightly adherent to the pulmonary capillary endothelium. At this time, horses (order Perissodactyla) are the only species outside the mammalian order Artiodactyla (sheep, pig, cattle) documented to have reactive intravascular macrophages. Compared with other species, low doses of particles induced marked hemodynamic responses; horses appear to be more sensitive to IV administered particles than are other species studied.
Development of an experimental model of hypothyroidism in cockatiels (Nymphicus hollandicus)
Authors: Harms Craig A. , Hoskinson James J. , Bruyette David S. , Carpenter James W. , Galland John , Veatch Jobna K. , Wilson Sandra C. , Baier Jeffrey G.
Published: January 2024

Hypothyroidism is 2 possible predisposing factor in a number of disorders of companion psittacine birds. We developed and validated a thyroid-stimulating hormone (tsh) response testing protocol for cockatiels (Nymphicus hollandicus), using 0.1 IU of tsh/bird given IM, with blood sample collection at 0 and 6 hours after tsh, and a commercial radioimmunoassay for thyroxine (T4). This protocol was used to document a seasonal sex difference in stimulated T4 values— females responded with higher T4 values than those in males in summer—and a stress-induced depression of baseline T4 values was detected in a group of cockatiels with normal tsh response. An experimental model for mature-onset hypothyroidism in cockatiels was created by radiothyroidectomizing cockatiels with 3.7 MBq (100 μCi) of 131I/bird given IV. Induction of the hypothyroid state was confirmed by baseline T4 concentration, tsh response test results, thyroid pertechnetate scintigraphy, and gross and microscopic examinations. Classical signs of hypothyroidism (eg, hypercholesterolemia, obesity, poor feathering) were lacking or mild at 48 days after thyroid ablation.
Structure of equine type I and type II collagens
Authors: Todbunter Rory J. , Wootton Joyce A. M. , Lust George , Minor Ronald R.
Published: January 2024

Collagen type I was purified from equine skin and flexor tendon, and type II collagen was purified from equine articular cartilage. The proteoglycans in these tissues were extracted, using guanidine hcl; the collagens were solubilized, using pepsin digestion, then were selectively precipitated with NaCl. Gel electrophoresis indicated that the precipitates contained only type I or type II collagen. Amino acid analysis indicated that collagen constituted > 97% of the total protein in the precipitates. Hydroxylation of proline was 42.0 ± 0.6% (mean ± sem) in α1(I) and α2(I), and was 48.1 ± 1.3% in α1(ID chains. The hydroxylation of lysine was 23.2 ± 0.7% in α1(I) and 34.1 ± 0.9% in α2(D) chains from tendon, and 49.6 ± 4.3% in a1( chains from cartilage. The cyanogen bromide (CB)-peptide patterns of chromatographically purified equine α2(I) and α1(II) chains were similar to those published previously for rat, bovine, and human α2 and α1 chains. However, the CB-peptide pattern of the equine α1(I) chain resembled the guinea pig α1(I) chain, which has no methionine between CB7 and CB6. Purified equine α1(I)CB7,6 contained no methionine, methionine sulfoxide, or homoserine lactone. Mass of 42.26 kd was determined by use of mass spectrometry, and N-terminal sequence analysis established that the first 12 amino acids of this CB7,6 were identical to the sequence of human α1(I)CB7. Because of this species specific difference in structure of the α1(I) chain, equine CB-peptides should be used as standards in studies of variations in the proportions of type I and type II collagens in equine tissues expressing the phenotype of fibrous tissue and cartilage.
Reliability of single urine and serum samples for estimation of 24-hour urinary uric acid excretion in six healthy Beagles
Authors: Bartges Joseph W. , Osborne Carl A. , Felice Lawrence J. , Unger Lisa K. , Bird Katherine A. , Koehler Lori A. , Chen Menglan
Published: January 2024

Urine uric acid-to-urine creatinine ratios (uua:uc), urine uric acid concentrations, urine uric acid concentrations corrected for glomerular filtration rate, and urinary uric acid fractional excretions were compared with 24-hour urinary uric acid excretions measured in 6 healthy adult female Beagles. Comparisons, using correlation analysis, were made when dogs consumed a 10.4% protein (dry weight), casein-based diet and a 31.4% protein (dry weight), meat-based diet. The uua:uc, urine uric acid concentrations corrected for glomerular filtration rate, and urinary uric acid fractional excretions were not reliable estimates of 24-hour urinary uric acid excretions during consumption of either diet. Urine uric acid concentrations in samples collected 2, 4, 6, and 24 hours after initiation of collection correlated with 24-hour urinary uric acid excretions when dogs consumed the casein-based diet; correlation was not found at any time interval when dogs consumed the meatbased diet. Therefore, determination of 24-hour urinary uric acid excretion is recommended because uua:uc are unreliable.
Tonometry of normal eyes in raptors
Authors: Stiles Jean , Buyukmihci Nedim C. , Farver Thomas B.
Published: January 2024

An applanation tonometer was used to estimate intraocular pressure in normal eyes of several species of raptors. No bird had active injury or illness, though some were nonreleasable to the Wild because of previous injury. Mean (± sd) intraocular pressure was 20.6 (± 3.4) mm of Hg in red-tailed hawks (Buteo jamaicensis, n = 10), 20.8 (± 2.3) mm of Hg in Swainson's hawks (Buteo swainsoni, n = 6), 21.5 (± 3.0) mm of Hg in golden eagles (Aquila chrysaetos, n = 7), 20.6 (± 2.0) mm of Hg in bald eagles (Haliaeetus leucocephalus, n = 3), and 10.8 (± 3.6) mm of Hg in great horned owls (Bubo virginianus, n = 6). There was no significant difference in intraocular pressure between hawks and eagles. Mean pressure in great horned owls was significantly (P < 0.01) lower than pressure in hawks or eagles. Reliable intraocular pressure readings could not be obtained in barn owls (Tyto alba).
Measurement of volatile fatty acid disappearance and fluid flux across the abomasum of cattle, using an improved omasal cannulation technique
Authors: Rupp Gary P. , Kreikemeier Kelly K. , Perino Louis J. , Ross Gary S.
Published: January 2024

Six steer calves, surgically fitted with a permanent cannula in the rumen, omasoabomasal orifice, abomasum, and duodenum were used to determine total digesta flow and volatile fatty acid (vfa) concentration at various points in the digestive tract. The omasoabomasal cannula had a flexible nylon sleeve that could be exteriorized through the abomasal cannula to collect omasal effluent.

Three experiments were conducted: 95% concentrate fed at maintenance (2,670 g of organic matter intake/d); 95% concentrate fed ad libitum (3,484 g of organic matter intake/d); and brome hay fed ad libitum (2,927 g of organic matter intake/d). Calves were offered the diet in 12 portions daily. Each experiment included a 14-day adaptation period and a 2-day sample collection period during which chromic oxide was used as a digesta flow marker. In all 3 experiments, vfa concentration was greatest in the rumen sample (84 to 109 mM), intermediate in the omasal sample (32 to 40 mM), and lowest in the duodenal sample (7 to 14 mM, P < 0.01). Total fluid flow at the duodenum was 13 to 18 L/d greater than flow at the omasum (P < 0.10). Omasal vfa flow was twofold greater than duodenal vfa flow (P < 0.05). There was a net fluid increase and net disappearance of vfa across the abomasum. The cannulation technique was useful for repeated collection of omasal effluent for at least 3 months.
Comparison of cardiac function in double-muscled calves and in calves with conventional muscular conformation
Authors: Amory Héléne , Desmecht Daniel J.-M. , Linden Annick S. , Mc Entee Kathleen , Rollin Frédéric A. , Beduin Jean-Marie L. , Genicot Bruno C. , D'orio Vincent , Lekeux Pierre M.
Published: January 2024

During growth, central venous, right ventricular, pulmonary arterial, pulmonary capillary wedge, and systemic arterial pressures, heart rate, and cardiac output were repeatedly measured in 41 Friesian calves, considered as having conventional muscular conformation, and in 19 Belgian White and Blue double-muscled calves. A total of 123 and 70 recordings were collected in conventional and double-muscled calves, respectively. These circulatory indices were calculated: stroke volume, cardiac and stroke indices, pulmonary and systemic pulse pressures, pulmonary and systemic vascular resistance indices, and right and left ventricular work indices.

Results indicated that systemic arterial and pulse pressures, as well as cardiac output, stroke volume, cardiac and stroke indices, and right and left ventricular work indices were significantly (P ≤ 0.05 to 0.001) lower but, in contrast, pulmonary and systemic vascular resistance indices were significantly (P ≤ 0.001) higher in double-muscled than in conventional calves. Right-sided vascular pressures and heart rate were similar in the 2 groups. These results indicated that global cardiac performance may be considerably poorer in double-muscled calves. Diminished cardiac performance of double-muscled calves appears to be related neither to relative bradycardia nor to reduced ventricular preload. The potential role of increased ventricular afterload or of reduced myocardial contractility in double-muscled cattle should be determined by direct measurements.
Molecular forms of β-endorphin in the canine pituitary gland
Authors: Young Diane W. , Kemppainen Robert J.
Published: January 2024

Acid extracts of anterior and intermediate lobes of the pituitary gland from 4 dogs were fractionated by cation-exchange high-performance liquid chromatography and analzyed by radioimmunoassay, using 2 antibodies: one specific for the midregion of β-endorphin (β-end) and the other specific for the N-terminal region of N-acetylated β-end. Identification of peaks of canine β-end immunoreactivity was based on the retention times relative to those of synthetic human β-end standards, with predicted variations attributable to differences in the β-end amino acid sequences between the 2 species. The canine anterior lobe was found to contain almost exclusively β-end (1–31). By contrast, the intermediate lobe contained substantial amounts of N-acetylated and C-terminally shortened forms of β-end. The predominant forms of β-end in canine intermediate lobe were, in decreasing order of abundance: β-end (1–27), β-end (1–31), β-end (1-26), Acβ-end (1–27), Acβ-end (1–26) and Acβ-end (1–31). Individual β-end immunoreactivity profiles varied, but the general pattern was consistent among the 4 dogs.
C-Reactive protein concentration in dogs with inflammatory leukograms
Authors: Burton Shelley A. , Honor David J. , Mackenzie Allan L. , Eckersall P. David , Markham R. J. Frederick , Horney Barbara S.
Published: January 2024

Serum C-reactive protein (crp) concentration was measured, using an automated immunoturbidimetric assay, in 44 clinically normal dogs and 67 dogs with band neutrophil count ≥ 109 cells/L, and values were found to be significantly (P ≤ 0.05) different. Correlation of serum crp concentration and band neutrophil count in the 67 dogs with ≥ 109 band neutrophils/L resulted in a statistically significant (P ≤ 0.05), but low correlation coefficient of 0.34. Serum crp concentration and cbc values were determined for 6 clinically normal dogs undergoing anesthesia (controls) and 6 clinically normal dogs undergoing anesthesia and ovariohysterectomy. Significant alterations in cbc results and serum crp concentration, compared with baseline values, were lacking in dogs of the control group. Serum crp concentration was significantly (P ≤ 0.05) increased above baseline values in dogs undergoing surgery and was significantly (P ≤ 0.05) increased, compared with values in control dogs by 12 hours after surgery. In dogs undergoing surgery, serum crp concentration was also significantly (P ≤ 0.05) different from values in control dogs at 28 and 36 hours, but not at the 76- and 124-hour sample collection times. Alterations in cbc values compatible with possible or convincing inflammation were detected in 83% of the dogs undergoing surgery at the 8- and 12-hour postsurgery sample collection times, 100% of dogs at 16, 22, 28, and 36 hours after surgery, 83% of dogs at 52 and 76 hours after surgery, 67% of dogs at 100 hours after surgery, and 0% of dogs at 124 hours after surgery. It was concluded that significant increases in crp concentration in dogs with surgical trauma were not detected earlier than cbc alterations compatible with possible or convincing inflammation.
Adjuvanted subunit vaccines for the control of Salmonella enteritidis infection in turkeys
Authors: Charles Samuel D. , Hussain Iftikhar , Choi Cheong-Up , Nagaraja Kakambi V. , Sivanandan V.
Published: January 2024

Liposomes and immunostimulating complexes (iscom) are adjuvants that have been known to potentiate the immune response to membrane proteins. Adjuvanted outer membrane proteins (omp) from Salmonella enteritidis were evaluated for their protective efficacy against S enteritidis infection in turkeys. The adjuvanted vaccines prepared for evaluation were: positive or negatively charged liposomes, lipid-conjugated iscom, and mineral oil vaccines. These preparations were compared with that of a whole cell bacterin and protein alone. After vaccination, turkeys were challenge-exposed with a nalidixic acid-resistant strain of S enteritidis. They were monitored for clinical signs of disease, antibody response, bacterial shedding pattern, and clearance of the challenge S enteritidis from internal organs. Results indicated a significantly (P < 0.05) higher antibody response to the positively charged liposomal omp vaccine, compared with the whole cell bacterin. The antibody response to positively charged liposomal omp vaccine was greater when a booster dose of this preparation was given. Shedding of S enteritidis was decreased in all vaccinated and challenge-exposed turkeys (P < 0.001). The tissues from a high percentage (90 to 100%) of birds that received a booster vaccination of the liposomal ( + or − ) and iscom vaccine were culture-negative for S enteritidis.
Histologic and ultrastructural changes after large-colon torsion, with and without use of a specific platelet-activating factor antagonist (WEB 2086), in ponies
Authors: Wilson D. V. , Patterson J. S. , Stick J. A. , Provost P.J.
Published: January 2024

The role of platelet-activating factor (paf) in mediating the colonic damage that develops after large-colon torsion was studied in 14 ponies. Morphologic changes in areas of the ascending colon and selected abdominal and thoracic viscera after 1 hour of large-colon torsion and 3 to 5 hours of reperfusion were determined, as well as the protective effects of systemic administration of a specific paf antagonist (WEB 2086). Ponies were selected then allocated at random and in equal numbers to 2 groups that received 1 of 2 treatments prior to induction of large-colon torsion: group 1 —control (saline solution), and group 2 — WEB 2086 (3 mg/kg of body weight loading dose and 3 mg/kg/h for the remainder of the study). In each pony, full-thickness tissue specimens from the gastrointestinal tract —cecum, pelvic flexure, left and right ventral colon, and right dorsal colon —heart, left lung, liver, left adrenal gland, spleen, and right kidney were collected and histologically evaluated. Edema, mucosal necrosis, and neutrophil infiltration in colonic sections were graded from 0 (normal) to 3 (most severe changes). Sections of liver and lung from 3 ponies in each group, and colon from 1 pony in each group, also were examined by transmission electron microscopy to determine the presence of ultrastructural alterations.

Ischemia and reperfusion induced marked changes in all sections of colon in all ponies: moderate to severe submucosal edema, moderate necrosis of the superficial epithelium and lamina propria, and necrosis of the mucosal crypt epithelium. Extra-vascular neutrophil accumulation was evident in all sections of colon and cecum, but not in other tissues. Ultrastructural lesions were not present in hepato-cytes or pneumocytes, or in the endothelial cells of liver, lung, and colon. Bacteria were observed by electron microscopy in 5% of hepatic sinusoids. Administration of a specific paf antagonist, WEB 2086, failed to reduce severity of the observed lesions, indicating that it was not cytoprotective at the dosage used in this model of ischemia-reperfusion injury.
Characterization of Toxoplasma and Trichinella isolates from muscles of black bears in Pennsylvania
Authors: Dubey J. P. , Briscoe Nancy , Gamble Ray , Zarlenga D. , Humphreys J. G. , Thulliez P.
Published: January 2024

During the hunting season of 1992, 322 black bears from Pennsylvania were examined for Toxoplasma gondii- and Trichinella spp-induced infections. Toxoplasma gondii antibodies were found in 79.8% of 322 bears–titer < 1:25 in 65 (20.2%), 1:25 in 18 (5.6%), 1:50 in 11 (34.5%) and 1:500 in 128 (38.7%) bears –by use of the modified agglutination test. Muscle tissues from 89 of these bears were bioassayed for T gondii parasites. Muscles from 64 bears, including heart from 1 bear, and heart alone from another bear, were digested in pepsin, and the digested samples were bioassayed in mice. Toxoplasma gondii was isolated from 5 bears; from the heart of 1, heart and skeletal muscles of 1, and skeletal muscles of 3. The T gondii antibody titers for the 5 bears with detectable T gondii were: ≥ 1:25 in all 5 bears by use of the modified agglutination test; < 1:10 (3 bears, considered Toxoplasma-negative), 1:20 and 1:320 by use of the Sabin-Feldman dye test; < 1:64 (3 bears, considered Toxoplasma-negative), 1:128, 1:512 by use of the indirect hemagglutination test, and < 1:16 (2 bears, considered Toxoplasma-negative), 1:32, 1:64, and 1:512 by use of the latex agglutination test. Toxoplasma gondii was not isolated from feces of 5 cats fed muscles from the remaining 25 bears with T gondii antibody titer < 1:25. Tissue cysts of the 4 T gondii isolates from bears were rendered noninfective by freezing at – 13 C. Antibodies against Trichinella spp were found in 6 (1.8%) of 319 bear sera; Trichinella spp larvae were detected in muscle digests of 2 of 63 bears, and in histologic sections of muscles from 3 of 162 bears. Genetic typing indicated that the 2 Trichinella isolates from bears were a sylvatic genotype and were not the species found in domestic pigs.
Tidal breathing flow-volume loops in horses with recurrent airway obstruction (heaves)
Authors: Petsche Vicki M. , Derksen Frederik J. , Robinson N. Edward
Published: January 2024

Tidal breathing flow-volume (tbfv) loops were determined in a group of control horses and in horses affected with recurrent airway obstruction (heaves). The latter group was studied when the condition was in remission and under increasing amounts of airway obstruction as reflected by measurements of change in pleural pressure, pulmonary resistance, and dynamic compliance. The tbfv loops of control horses had biphasic inspiratory and expiratory patterns; peak inspiratory and peak expiratory flows were detected early in inspiration and expiration, respectively. Tidal volume was unaffected by heaves, but at all stages of heaves, respiratory frequency was increased principally because of shorter inspiratory time, and therefore, inspiratory flow rate was increased. In horses with heaves, tbfv loops did not have a biphasic pattern; peak inspiratory flow was observed late in inspiration, and peak expiratory flow was observed early in expiration. As airway obstruction became more severe, peak expiratory flow increased as pulmonary resistance increased so that, during severe airway obstruction, tbfv loops had a characteristic appearance with high peak expiratory flow early in expiration followed by low flow rate.
Endoscopic evaluation of the nasopharynx, pharynx, and larynx of Jersey cows
Authors: Anderson David E. , DeBowes Richard M. , Gaughan Earl M. , Yvorchuk Kathleen E. , St.Jean Guy
Published: January 2024

Endoscopy of the nasopharynx, pharynx, and larynx was performed in each of 25 adult Jersey cows, age and body weight of which ranged from 2 to 6 years and 300 to 365 kg, respectively. The endoscopic appearance of normal anatomic structures of the proximal portion of the airway were described. Observations specific to female dairy cattle were: the nasal septum, which tapered caudodorsally in the distal third of the nasal passage; the ability to observe both ethmoturbinates from the same viewing side; presence of a pharyngeal septum; the nasopharyngeal opening of the auditory tubes dorsolateral to the pharyngeal septum; and the appearance of the larynx — a triangular epiglottis with round borders and prominent corniculate process of the arytenoid cartilages. Tracheoscopy was performed in 13 cows. Of 11 cows for which the soft palate could be observed immediately after withdrawing the endoscope, 7 had dorsal displacement of the soft palate.
Diagnosis of paratuberculosis in dairy cattle, using enzyme-linked immunosorbent assay for detection of antibodies against Mycobacterium paratuberculosis in milk
Authors: Sweeney Raymond W. , Whitlock Robert H. , Buckley Carol L. , Spencer Pam , Rosenberger Ann E. , Hutchinson Lawrence J.
Published: January 2024

An elisa containing lipoarabinomannan (lam) antigen was used to detect antibodies in milk and serum for diagnosis of Mycobacterium paratuberculosis infection in dairy cattle. In experiment 1, milk and serum samples were obtained from 25 cows, and subjected to lam elisa testing immediately, and after 1 year of storage at −70 C. Milk samples, with and without a commonly used chemical preservative, were tested. There was no significant difference in lam elisa results between fresh and frozen samples or between preserved and unpreserved milk samples. In experiment 2, milk samples were collected daily from 30 cows over a 14-day period. The day-to-day coefficient of variation was 0.19 for milk lam elisa and was 0.15 for serum lam elisa, with no statistically significant time effect detected. In experiment 3, single milk, serum, and fecal samples were obtained from 764 cows. The fecal samples were cultured for M paratuberculosis to identify infected cows, and the serum and milk samples were subjected to lam elisa testing. Results were compared, using the area under the receiver operating characteristic curves. The milk lam elisa had specificity (± 95% confidence limits) of 87 ± 8.1% when the cutoff was set at 50% sensitivity, and specificity of 83 ± 9.1% when sensitivity was set at 60%. The area under the receiver operating characteristic curve was 0.85 ± 0.03 for the milk elisa and 0.75 ± 0.02 for the serum elisa. In this population of cattle, the milk lam elisa had comparable accuracy to serum lam elisa, although the milk lam elisa was slightly less reproducible (higher coefficient of variation).
Substance P and calcitonin gene-related peptide-like immunoreactive nerve fibers in lungs from adult equids
Authors: Sonea Ioana M. , Bowker Robert M. , Edward Robinson N. , Broadstone Richard V.
Published: January 2024

Distribution of pulmonary nerves immunoreactive for either substance P or calcitonin gene-related peptide was determined, using immunohistochemical methods on healthy lungs from adult equids. The overall patterns of distribution of substance P and calcitonin gene-related peptide-like immunoreactivity were similar. Distribution of immunoreactive nerves was not uniform throughout the lungs; nerve fibers immunoreactive for these peptides were more frequently observed near the hilus of the lung than in the caudal lobes or in the periphery of the lung. Nerve fibers immunoreactive for substance P or calcitonin gene-related peptide were most abundant in the lamina propria of the trachea and larger airways, particularly within and directly below the airway epithelium; they were also frequently associated with bronchial and pulmonary vessels. Presence of nerve fibers immunoreactive for substance P and calcitonin gene-related peptide in peribronchial neural ganglia indicated that these sensory nerves may modulate parasympathetic regulation of pulmonary function. Nerve fibers immunoreactive for substance P and calcitonin gene-related peptide were, therefore, well placed to detect inhaled agents and to contribute to the pulmonary response to irritants and pathogens.
Analysis of mononuclear cell functions in Holstein cattle with leukocyte adhesion deficiency
Authors: Nagahata Hajime , Nochi Hiromi , Sanada Yasuyuki , Tamoto Koichi , Noda Hiroshi , Kociba Gary J.
Published: January 2024

Lymphocyte functions in cattle affected with leukocyte adhesion deficiency (lad, termed blad in cattle) were evaluated by lymphocyte markers, blastogenic response, and immunoglobulin concentrations; mononuclear phagocyte functions were assessed by chemotactic and luminol-dependent chemiluminescent (cl) responses to determine the effects of impaired expression of leukocyte CD18 on mononuclear cell functions. Deficient CD18 expression on lymphocytes and mononuclear phagocytes from cattle with blad was clearly detected by use of flow cytometric analysis. There were no significant differences in the population of peanut agglutinin (pna)-positive and surface immunoglobulin-bearing blood lymphocytes from clinically normal cattle and cattle with blad, as determined by flow cytometric analysis. Lymphocytes from cattle with blad had strong mitogen-induced blastogenic responses, which were greater than those from controls. Adherence of mononuclear phagocytes from cattle with blad was markedly impaired, and their chemotactic responses had diminished values, compared with those of controls. Luminol-dependent cl of mononuclear phagocytes from affected cattle, stimulated by opsonized zymosan, had significantly (P < 0.01) decreased values, compared with those of controls. Concentrations of IgG were markedly increased in serum from cattle with blad, compared with those in controls. These results indicated that impaired expression of leukocyte CD18 has marked effects on adhering activity of mononuclear phagocytes, and significantly inhibits cl response of mononuclear phagocytes mediated by inactivated-complement 3b-dependent functions. High selective immunoglobulin concentrations indicated that lymphocytes of B-cell lineage may have normal function.
Comparison of microscopic and flow cytometric detection of platelet antibody in dogs suspected of having immune-mediated thrombocytopenia
Authors: Kristensen Annemarie T. , Weiss Douglas J. , Klausner Jeffrey S. , Laber Judy , Christie Douglas J.
Published: January 2024

A flow cytometric platelet immunofluorescence assay (fc-pifa) was compared with a previously developed microscopic platelet immunofluorescence assay (mi-pifa) for detection of circulating platelet antibody. Both assays were performed on serum from 10 healthy dogs with normal platelet count, and on serum from 27 thrombocytopenic dogs—18 had primary immune-mediated thrombocytopenia (imt), and 9 had imt in addition to other immune-mediated disease (secondary imt). Both assays yielded negative results for all control dogs. The mi-pifa and fc-pifa results were in agreement in 23 dogs with imt (14 positive and 9 negative). There was linear correlation between mi-pifa scores and fc-pifa results (r = 0.873). Positive results were obtained for 55.5% of the dogs with suspected imt, using the mi-pifa, compared with 67%, using the fc-pifa; however, the difference was not statistically significant. Use of fresh or frozen fixed donor platelets as the antigen source yielded similar results in the fc-pifa.
Cardiopulmonary effects of medetomidine in heartworm-infected and noninfected dogs
Authors: Venugopalan C. S. , Holmes E. P. , Fucci V. , Keefe T. J. , Crawford M. P.
Published: January 2024

Medetomidine, an investigational drug indicated for clinical use as a short-term chemical restraint in dogs, was evaluated for its cardiopulmonary effects, in 10 naturally heartworm-infected (HW+) and 10 noninfected (hw−) Beagles. The drug was randomly administered IV (30 μg/kg of body weight) and IM (40 μg/kg) in single injections to all dogs. Heart rate, respiratory rate, ecg, blood gas tensions, blood pH, central venous and arterial pressures were measured at 0, 15, 30, 60, 90, 120, and 180 minutes.

Medetomidine induced an immediate significant (P ≤ 0.001) increase in mean arterial blood pressure followed by decreased blood pressure that remained below normal throughout the study in both groups, irrespective of route of administration. Medetomidine increased central venous pressure, over time, for both groups and both routes of administration. Heart and respiratory rates were significantly (P ≤ 0.001) decreased after medetomidine administration and remained reduced for the duration of the study in all dogs. The ecg variables were not significantly different between groups or between routes of administration. The HW+ dogs tended to have higher mean Pao2 than did HW− dogs at several postinjection determination times, particularly when the drug was administered IM. The Pao2; decreased during the first 30 minutes in both groups and tended to increase gradually thereafter. The pH decreased over time for both groups and both routes. A significant (P ≤ 0.05) decrease in pH was seen in the HW− dogs, compared with HW+ dogs at each measuring time for both routes. The Paco2 did not significantly change for groups or routes.

In general, bradycardia was the predominant cardiovascular effect seen after medetomidine administration in all dogs, irrespective of route. Lowering of blood pressure and heart rate (after a transient blood pressure increase) was synchronized with sedation in these dogs. The overall clinical response with regard to cardiopulmonary effects in HW+ dogs was similar to that in HW− dogs.
Evaluation of quantitative acid-base balance and determination of unidentified anions in swine
Authors: Frischmeyer Karen J. , Moon Paula F.
Published: January 2024

Arterial blood samples were collected from 19 anesthetized pigs before and after hemorrhage was induced. Blood gas tensions and concentrations of sodium, potassium, chloride, lactate, and total protein were measured. Results indicated that hydrogen ion (H+) concentration calculated from a specific formula was a biased and imprecise estimate of measured H+ concentration. The bias was 5.45 nEq/L, with limits of agreement from −7.92 to 18.83 nEq/L. Because albumin is the fraction of plasma protein most important in acid-base balance, the agreement between predicted and measured H+ concentration was reevaluated, using an albumin charge estimate and a reference swine albumin-to-globulin ratio. This improved the ability of the formula to predict H+ concentration; the bias decreased to 1.33 nEq/L with limits of agreement from −12.16 to 9.49 nEq/L. The formula and a simplified approach for clinical application were biased and unacceptably imprecise estimators of lactate (L−) concentration. The formula approach underestimated L− concentration by 2.8 (−12.4, 6.7) mEq/L, whereas the simplified method overestimated L− concentration by 5.0 (−3.8, 13.9) mEq/L.
Effects of chemical restraint on the endoscopic appearance of laryngeal and pharyngeal anatomy and sensation in adult cattle
Authors: Anderson David E. , Gaughan Earl M. , DeBowes Richard M. , Lowry Stephen R. , Yvorchuk Kathleen E. , Jean Guy St.
Published: January 2024

Effects of 2 drugs commonly used for chemical restraint of cattle were evaluated for their effect on laryngeal and pharyngeal anatomy, function, and response to stimuli. Eighteen adult Jersey cows, free of respiratory tract disease, were studied. Cows were assigned at random to 1 of 3 treatment groups. Endoscopic evaluations were performed before and at a predetermined time interval after administration of each drug. Responses to stimuli were evaluated by stimulating 7 preselected sites (epiglottis, left and right arytenoid cartilages, left and right vocal folds, and left and right dorsolateral pharyngeal walls) with a closed, transendoscopic biopsy probe. Xylazine HCl (0.05 mg/kg of body weight, IV) was administered to group-1 cows (n = 6), and endoscopy was repeated 5 minutes after administration of the drug. Xylazine (0.07 mg/kg, IV) was administered to group-2 cows (n = 6), and endoscopy was repeated 5 minutes after administration of the drug. Acepromazine maleate (0.035 mg/kg, IV) was administered to group-3 cows (n = 6), and endoscopy was repeated 10 minutes after administration of the drug. Responses to stimuli were scored as brisk (0), moderate (1), slow (2), and absent (3). Scores for responses to stimuli were compared, using the Wilcoxon signed-rank test for data within groups, and a general linear models procedure, using the Kruskal-Wallis test between groups. Interobserver agreement rates were generated for each group. A value of P< 0.05 was considered significant.

Xylazine profoundly changed laryngeal sensitivity and function at both dosages. The corniculate processes of the arytenoid cartilages were observed to be in a markedly adducted position after sedation.

Response to stimuli was significantly (P = 0.03) slower than normal after sedation, using both dosages. Displacement of the soft palate dorsal to the epiglottis was persistent in 50% of the cows after stimulation tests subsequent to sedation with xylazine. Acepromazine had a mild effect on laryngeal sensitivity and function. The corniculate processes of the arytenoid cartilages were observed in paramedian position after sedation. Acepromazine did not significantly affect responses to stimuli. Effects of sedation on responses to stimuli were not significantly different for groups 1 and 2. However, effects for group 3 were significantly different from those for groups 1 and 2 (P = 0.006 and 0.004, respectively).

Endoscopic evaluation of the proximal portion of the respiratory tract of cattle should be performed without sedation, when possible. If sedation is required to facilitate restraint for endoscopy, acepromazine maleate is recommended over xylazine on the basis of results of this study.
Radiographic geometric variation of equine long bones
Authors: Hanson Peter D. , Markel Mark D.
Published: January 2024

As more sophisticated research is performed to refine fracture fixation techniques for horses, it is important that normal values for the geometric properties of the bones of the appendicular skeleton be determined and that suitable controls be available. We evaluated the geometric properties of total bone width, cortical bone width, and medullary canal/trabecular bone width measured from 2 radiographic projections of equine long bones (humerus, radius, third metacarpal bone, femur, tibia, and third metatarsal bone) obtained from a general population of horses. Measurements were performed on slices separated by intervals equal to 5% of the bone's length. Slices were then grouped into 5 regions: proximal epiphysis, proximal part of the metaphysis, diaphysis, distal part of the metaphysis, and distal epiphysis. Results validated use of the contralateral bone as a control for assessing experimental models or clinical cases. Of 858 homotypic slice comparisons between left and right bones, significant (P ≤ 0.05) differences were detected in 31 (3.6%) of the comparisons. Of 168 homotypic region comparisons, significant differences were observed in 3 (1.8%) of the comparisons. The greatest variation between left and right bones was observed in metaphyseal regions, areas with bony protuberances, and regions with prominent bone superimposition. At a power of 0.8 for the statistical tests performed in this study, the mean homotypic variation of bones in each region is < 5.8% for the proximal epiphysis, 11.3% for the proximal part of the metaphysis, 6.8% for the diaphysis, 12.2% for the distal part of the metaphysis, and 5.2% for the distal epiphysis.
Pulmonary vascular pressures of strenuously exercising Thoroughbreds after administration of flunixin meglumine and furosemide
Authors: Manohar Murli
Published: January 2024

High-intensity exercise results in a dramatic increase in mean pulmonary capillary blood pressure of horses, and administration of furosemide 4 hours before exertion significantly attenuates this exercise-induced increment. To test whether this effect of furosemide is mediated via release of prostaglandins, right atrial and pulmonary vascular pressures were measured in 8 healthy, sound, exercise-trained Thoroughbreds at rest and during incremental-step exercise on a treadmill. Horses were studied on 3 separate occasions: after IV administration of saline (0.9% NaCl) solution, after administration of furosemide (250 mg, IV, 4 hours before exercise) alone, and after administration of flunixin meglumine (1.1 mg/kg, IV, q 8 h for 3 days) and furosemide (250 mg, IV, 4 hours before exercise; last dose of flunixin meglumine was administered 90 seconds after furosemide injection). Experiments on each horse were separated by at least 7 days and were performed in random order. At rest and at the highest workload (14.5 m/s on a 5% uphill incline), mean pulmonary capillary blood pressure recorded after administration of furosemide alone was not significantly different from that recorded after administration of flunixin meglumine and furosemide. However, these values were significantly (P< 0.05) less than corresponding values of mean pulmonary capillary blood pressure recorded after administration of saline solution. Thus, it was concluded that furosemide-induced attenuation of the increment in pulmonary capillary blood pressure during strenuous exercise is probably not mediated via prostaglandin production.
In vitro comparison of the standard short limb cast and three configurations of short limb transfixation casts in equine forelimbs
Authors: McClure Scott R. , Watkins Jeffrey P. , Bronson Dwight G. , Ashman Richard B.
Published: January 2024

Axial stability of equine oblique proximal phalangeal osteotomies with application of the standard short limb cast or 1 of 3 configurations of transfixation casts was determined in vitro. Transfixation cast methods included use of parallel pins, divergent pins, or parallel pins incorporating a metal walking bar. Displacement at the osteotomy was recorded for each limb at 4,448 N. Standard short limb casts provided significantly (P = 0.0002) less axial stability than did any form of transfixation cast. Significant differences were not found between the 3 transfixation casts.
Effect of isoflurane on hematologic variables in ferrets
Authors: Marini Robert P. , Jackson Lynn R , Esteves Maria I. , Andrutis Karl A. , Goslant Carol M. , Fox James G.
Published: January 2024

Effects of isoflurane on the cbc in ferrets were studied. There was rapid decrease in all hematologic variables after induction of anesthesia. Percentage reductions in indices of the erythron (hematocrit, rbc count, hemoglobin concentration) exceeded those of plasma protein concentration and wbc count at the first postinduction time point. There was little additional decrease in these variables for the duration of anesthesia. The values had partially recovered to preanesthetic baseline at 45 minutes after anesthesia. Although these alterations appear to be well tolerated in healthy ferrets, care should be exercised when subjecting anemic, geriatric, or debilitated ferrets to isoflurane-induced anesthesia.
Enteric pathogens in intensively reared veal calves
Authors: McDonough Sean P. , Stull Carolyn L. , Osburn Bennie I.
Published: January 2024

Observations were made on development of diarrhea in special - fed calves (n = 460) on 8 commercial facilities during 2 successive 16-week production cycles at weeks 0, 2, 4, 8, 12, and 16. A total of 23% were affected, with peak number of calves with diarrhea observed at week 0. Suspected enteropathogens were identified in 86 % of these calves, most commonly cryptosporidia, coronavirus, and rotavirus. Identified potential zoonotic pathogens included Giardia and Salmonella spp and verotoxigenic Escherichia coli. Noncytopathic bovine viral diarrhea virus was isolated from 6 calves that had repeated bouts of illness. Only 22% of calves entering the veal facilities had adequate transfer of passive immunity. At week 0, serum IgG concentration in calves that subsequently died or had diarrhea was lower (P < 0.001) than that in healthy calves. All calves that died (n = 6) during the first 4 weeks of production had complete failure of transfer of passive immunity.