bluuebunny/crossref_metadata_2025 huggingface dataset:
Lymphocyte reactivity to antigens of Haemonchus contortus in antigen-inoculated and H contortus-naive lambs
Authors: Torgerson P. R. , Lloyd S.
Published: January 2024

Lambs were inoculated during either fetal or early neonatal life with antigens of Haemonchus contortus (HcAg) third-stage larvae, or ovalbumin (ova), or were left untreated. By the time lambs were 4 weeks old, blood lymphocytes from all of them responded to HcAg. This was evident in all lambs, regardless of the previous inoculation regimen, although higher response was seen in HcAg-inoculated lambs, compared with naive lambs. Only lambs inoculated with ova had ova-specific lymphocyte activity. In HcAg-naive lambs, the maximal HcAg lymphocyte response was observed between the ages of 5 and 25 weeks, with gradual decrease thereafter. In vitro detection of HcAg-reactive lymphocytes was affected by antigen concentration and presence of plasma. Plasma inhibited HcAg-reactive lymphocytes from all lambs at high in vitro antigen concentration and completely abrogated the response in H contortus antigen-naive lambs.
Effects of ketamine infusion on halothane minimal alveolar concentration in horses
Authors: Muir William W. , Sams Richard
Published: January 2024

Eight adult horses were used in a study to determine ketamine's ability to reduce halothane requirement. To obtain steady-state plasma concentrations of 0.5, 1.0, 2.0, 4.0, and 8.0 μg/ml, loading doses and constant infusions for ketamine were calculated for each horse on the basis of data from other studies in which the pharmacokinetic properties of ketamine were investigated. Blood samples for determination of plasma ketamine concentrations were collected periodically during each experiment. Plasma ketamine concentrations were determined by capillary gas chromatography/mass spectrometry under electron-impact ionization conditions, using lidocaine as the internal standard. Halothane minimal alveolar concentration (mac; concentration at which half the horses moved in response to an electrical stimulus) and plasma ketamine concentration were determined after steady-state concentrations of each ketamine infusion had been reached. Plasma ketamine concentrations > 1.0 μg/ml decreased halothane mac. The degree of mac reduction was correlated directly with the square root of the plasma ketamine concentration, reaching a maximum of 37% reduction at a plasma ketamine concentration of 10.8 ± 2.7 μg/ml. Heart rate, mean arterial blood pressure, and the rate of increase of right ventricular pressure did not change with increasing plasma ketamine concentration and halothane mac reduction. Cardiac output increased significantly during ketamine infusions and halothane mac reduction. Our findings suggest that plasma ketamine concentrations > 1.0 μm/ml reduce halothane mac and produce beneficial hemodynamic effects.
Induction of fatty liver in cows by ethionine administration and concomitant decreases of serum apolipoproteins B-100 and A-I concentrations
Authors: Uchida Eiji , Katoh Norio , Takahashi Kiyoshi
Published: January 2024

Ethionine, an analogue of methionine, induces fatty liver in rats by inhibiting protein synthesis, including that of apolipoproteins in liver. Ethionine was administered to cows to elucidate the participation in fatty liver development of impaired triglyceride secretion from liver attributable to decreased apolipoprotein synthesis. The administration resulted in a significant increase of liver triglyceride contents. Several apolipoproteins were found to have decreased concentrations. In particular, apolipoprotein B-100 in very low-density (0.95 to 1.006 g/ml) lipoprotein and in low-density (1.006 to 1.063 g/ml) lipoprotein fractions was greatly reduced. The decreases of apolipoprotein B-100 concentrations in the 2 lipoprotein fractions were at least partly correlated to the decreased triglyceride concentrations in the respective fractions. Decreased concentrations of apolipoprotein A-I in high-density (1.063 to 1.210 g/ml) lipoprotein were also observed, although not as distinctly as with apolipoprotein B-100. Total cholesterol and phospholipid concentrations in low- and high-density lipoprotein fractions were decreased. The decrease in cholesterol was attributed to reduced concentrations of cholesteryl esters. It was suggested that the impaired lipid secretion from liver attributable to the decreased apolipoprotein concentrations has a role in ethionine-induced fatty liver of cows.
Functional, radiographic, and histologic assessment of healing of autogenous osteochondral grafts and full-thickness cartilage defects in the talus of dogs
Authors: Dew Terry L. , Martin Robert A.
Published: January 2024

A circular (5.5 mm diameter) full-thickness cartilage defect was created on the medial ridge of the talus in 12 skeletally mature dogs. In 6 dogs, the articular surface of the lesion was repaired, using an osteochondral graft obtained from the ipsilateral manus. The graft (digit I, first phalanx, distal articular surface and diaphysis) was contoured to obtain a press fit in the drilled talar recipient site. In 6 dogs, the lesion was not treated and healed by fibrous tissue replacement. Functional assessment (lameness, hock range of motion, joint stability, joint crepitus, and mid-femoral muscle circumference) was completed before surgery and at postoperative weeks 2 through 20. Radiographic assessment (periarticular soft tissue width, joint space width, osteophyte formation, and graft incorporation) was completed before surgery and at postoperative weeks 0, 6, 12, and 20. To facilitate histologic assessment, tissues were stained with toluidine blue and H&E. Histologic assessment of the articular surface on the surgically treated talus, ipsilateral tibia, and contralateral talus was completed, using a modification of the Mankin grading system. Subchondral bone was examined to assess graft viability and incorporation. Analysis of the ordinal data was completed, using a Mann-Whitney rank sum test.

All dogs were fully weight bearing by postoperative week 7. Dogs without grafts had significantly (P = 0.036) better clinical function at postoperative week 6. Significant difference in functional assessment was not evident at postoperative week 20. Immediate postoperative radiographic assessment revealed significant (P = 0.005) difference between nongrafted and grafted groups. Significant difference was not observed at postoperative week 6, 12, or 20. All grafts appeared radiographically incorporated by postoperative week 12. All grafts restored joint surface congruity, whereas 3 of 6 nongrafted lesions had poor articular congruity. Of 6 grafts, 4 partially retained normal hyaline cartilage, resulting in significantly (P = 0.014) lower Mankin grades. Significant histologic differences between groups were not apparent when the apposing tibia and control talus were examined.

Talar reconstruction by use of a phalangeal osteochondral graft is a viable surgical procedure. These data indicate that normal articular and subchondral architecture are more closely approximated by osteochondral reconstruction than by fibrous tissue repair.
Measurement of lymphoblast proliferative capacity of stimulated blood mononuclear cells from cattle with chronic paratuberculosis
Authors: Kreeger John M. , Snider Theron G.
Published: January 2024

Concanavalin A (conA) blast proliferation as a quantitative measure of lymphoblast proliferative capacity by blood mononuclear cell supernatants was measured in cattle naturally infected with Mycobacterium paratuberculosis and in healthy control cattle. Blast cell proliferation was significantly reduced in infected animals, compared with control cattle when blood mononuclear cells were stimulated with conA. Proliferation was significantly greater than media control when M bovis purified protein derivative and johnin were used to stimulate cells from the infected group. After sensitizing control and affected cattle with M paratuberculosis bacterin (live M bovis and keyhole limpet hemocyanin in Freund's incomplete adjuvant), infected animals had no difference in blast cell proliferative capacity with the mycobacterial antigens and conA stimulation, whereas healthy animals had significantly increased blast proliferation in response to all the sensitizing antigens. The blast cell proliferative capacity in infected animals with keyhole limpet hemocyanin stimulation was increased significantly after sensitization; however, it remained significantly less than that in the sensitized control group. These data indicate that cattle naturally infected with M paratuberculosis probably produce suboptimal interleukin-2 (il-2) activity in response to a potent il-2 inducer (conA) and fail to optimize il-2 activity when sensitized with a potent immunogen (keyhole limpet hemocyanin).
Blood types in cattle of Iberian ancestry and in Holsteins at various altitudes
Authors: Ramirez German , Miller Wilmer J. , Bittle Polly A. , Hidalgo Alvaro , Santacruz Rafael , Colice Gene
Published: January 2024

Gene frequencies of rbc antigens were determined in Holsteins and Colombian (criollas) cattle living at 3,000 m, and in cattle descended from fighting bulls (Vacas de lidia) living at 2,500 m. These frequencies were compared with those of Holsteins, cattle native to Florida (scrub cattle), longhorns, and native cattle from Brazil (caracu cattle) living at sea level. The criollas, Vacas de lidia, scrub cows, longhorns, and caracu are descendants of original Iberian stock introduced to the Americas. We found that despite common ancestry (scrub cattle, longhorns, criollas, and caracu), genetic differences may have been derived through years of demographic isolation. The most remarkable blood-group differences were found in the high prevalence of the B system phenogroup (heritable group of antigenic factors) BQA'G'34 in the Vacas de lidia, and of the S system phenogroup U1H' in these cattle and in caracu. Furthermore, the gene frequencies differed in the Holsteins maintained at moderately high altitude (descended from Holsteins kept at sea level), and may have been reflective of the need to adapt to moderately high altitude and chronic hypoxemic conditions. Blood group polymorphism was found in all groups of cattle, although it was reduced in the Vacas de lidia, possibly because their breeding has been carefully controlled and they appear to be highly inbred.
Evaluation of plasma cortisol and corticosterone responses to synthetic adrenocorticotropic hormone administration in ferrets
Authors: Rosenthal Karen L. , Peterson Mark E. , Quesenberry Kathy E. , Lothrop Clinton D.
Published: January 2024

Plasma cortisol and corticosterone responses of 8 clinically normal adult ferrets to synthetic acth (cosyntropin) were evaluated. Cosyntropin was administered iv at 4 dosages (0.5, 1.0, 5.0, and 10 μg/ kg of body weight) at 2- to 4-week intervals, with blood samples collected 60 and 120 minutes after injection. After completion of the studies, an additional acth stimulation test was performed by administering cosyntropin (1.0 μg/kg) im. The baseline plasma cortisol concentrations from all studies ranged from 25.9 to 235 nmol/L (mean ± sem = 73.8 ± 7.0 nmol/L), and plasma corticosterone values ranged from 1.7 to 47 nmol/L (mean ± sem = 8.3 ± 1.1 nmol/L). After iv administration of cosyntropin, plasma concentrations of cortisol and corticosterone increased significantly (P ≤ 0.05) and reached peak values at 60 minutes; however, there were no significant differences between plasma cortisol or corticosterone responses to the 4 dosages of cosyntropin. Intramuscular administration of 1.0 μg of cosyntropin/kg induced increases in plasma cortisol and corticosterone concentrations that were similar to the responses induced by iv administration of cosyntropin. The mean molar ratio of cortisol to corticosterone, calculated from the resting plasma concentrations, was approximately 9:1, whereas the acth-stimulated cortisol to corticosterone ratio was approximately 4:1. Results of this study indicated that administration of cosyntropin to clinically normal ferrets, at dosages ranging from 0.5 to 10 μg/kg, increased plasma concentrations of cortisol and corticosterone. Although cosyntropin stimulates the adrenocortical secretion of cortisol and corticosterone, cortisol appears to be the predominate circulating glucocorticoid in ferrets.
Identification of Pasteurella haemolytica A1 isolates from market-stressed feeder calves by use of enzyme and antimicrobial susceptibility profiles
Authors: Purdy Charles W. , Scanlan Charles M. , Loan Raymond W. , Foster Gene S.
Published: January 2024

An epidemiologic study of Pasteurella haemolytica serovar 1 (Ph1) in market-stressed feeder calves from 7 farms in eastern Tennessee was conducted. The nasal mucus of each calf was cultured sequentially at the farm of origin (day 0), at an auction market (day 133), and at a feedyard in Texas (days 141, 148, 155, and 169). Of the 103 calves tested, 77 were culture-positive, including 1 on day 0, 1 on day 133, 20 on day 141, 57 on day 148, 50 on day 155, and 14 on day 169. From the 143 Ph1 isolates, 20 enzyme profiles were determined by use of a commercial enzyme system that detects 19 enzymatic reactions; 4 antimicrobial susceptibility profiles were obtained, using the disk-diffusion method, which evaluated susceptibility to 11 antibacterial drugs. All isolates were positive for acid phosphatase and alkaline phosphatase, but were negative for α-galactosidase, α-mannosidase, β-glucosidase, β-glucuronidase, cystine aminopeptidase, N-acetyl-β-glucosaminidase, and trypsin. Other positive enzyme reactions included: leucine aminopeptidase, 140 Ph1 isolates; phosphohydrolase, 90 isolates; α-fucosidase, 63 isolates; esterase (C4), 59 isolates; valine aminopeptidase, 30 isolates; esterase lipase (C8), 24 isolates; β-galactosidase, 2 isolates; and α-glucosidase, chymotrypsin and lipase (C14), 1 isolate each. Thirty-four Ph1 profiles were identified, using combined enzyme and antimicrobial susceptibility profiles. The data indicate that the strains isolated during the feedyard period may have been determined more by farm of origin (P ≤ 0.001) than by habitation with calves from other farms while in the feedyard. The combined enzyme and antimicrobial susceptibility profile method is a rapid and simple epidemiologic technique for tracking Ph1 strains in market-stressed feeder calves.
Corneal thickness measured by ultrasonic pachymetry in cats
Authors: Gilger Brian C. , Wright James C. , Whitley R. David , McLaughlin Susan A.
Published: January 2024

Ultrasonic pachymetry was used to measure central superior peripheral, and temporal peripheral corneal thickness of 35 cats (70 eyes) with normal corneas, anterior chambers, and intraocular pressures. Mean central corneal thickness for both eyes in 3 locations for 35 cats was 578 ± 64 µm. Significant differences did not exist between central and peripheral corneal thickness. Corneal thickness increased significantly (P < 0.0001) with age up to 100 months. There was no significant difference in corneal thickness with regard to sex of the cats when adjusted for age.
Factors influencing fecal shedding of Campylobacter jejuni in dogs without diarrhea
Authors: Torre Elvira , Tello Montserrat
Published: January 2024

Rectal swab specimens were collected from 362 apparently healthy dogs of different origin, age, breed, and sex. Specimens were obtained in summer, autumn, and winter. Ninety-five thermophilic Campylobacter spp were isolated: C jejuni biotype I, n = 57, C jejuni biotype II, n = 1, C coli, n = 36, and C laridis, n = 1. Biotypes of C jejuni recovered were the same as those associated with Campylobacter-induced enteritis in human beings.

Prevalence of C jejuni was significantly (P < 0.05) greater: in dogs < 6 months old than in adult dogs; in dogs living under high density and cohabitation housing conditions for long periods; and in autumn.
Effect of hypercapnia on the arrhythmogenic dose of epinephrine in horses anesthetized with guaifenesin, thiamylal sodium, and halothane
Authors: Gaynor James S. , Bednarski Richard M. , Muir William W.
Published: January 2024

The effect of hypercapnia on the arrhythmo-genic dose of epinephrine (ADE) was investigated in 14 horses. Anesthesia was induced with guaifenesin and thiamylal sodium and was maintained at an end-tidal halothane concentration between 0.86 and 0.92%. Base-apex ECG, cardiac output, and facial artery blood pressure were measured and recorded. The ADE was determined at normocapnia (arterial partial pressure of carbon dioxide [Paco2 = 35 to 45 mm of Hg), at hypercapnia (Paco2 = 70 to 80 mm of Hg), and after return to normocapnia. Epinephrine was infused at arithmetically spaced increasing rates (initial rate = 0.25 μg/kg of body weight/min) for a maximum of 10 minutes. The ADE was defined as the lowest epinephrine infusion rate, to the nearest 0.25 μg/kg/min, at which 4 premature ventricular complexes occurred in a 15-second period. The ADE (mean ± SD) during hypercapnia (1.04 ± 0.23 μg/kg/min) was significantly (P < 0.05) less than the ADE at normocapnia (1.35 ± 0.38 μg/kg/min), whereas the ADE after return to normocapnia (1.17 ± 0.22 μg/kg/min) was not significantly different from those during normocapnia or hypercapnia. Baseline systolic and diastolic arterial pressures and cardiac output decreased after return to normocapnia. Significant differences were not found in arterial partial pressure of O2 (PaO2) or in base excess during the experiment. Two horses developed ventricular fibrillation and died during normocapnic determinations of ADE. Hypercapnia was associated with an increased risk of developing ventricular arrhythmias in horses anesthetized with guaifenesin, thiamylal sodium, and halothane.
Detection of Toxoplasma gondii antigen-containing immune complexes in the serum of cats
Authors: Lappin Michael R. , Cayatte Suzanne , Powell Cynthia C. , Gigliotti Andrew , Cooper Christi , Roberts Steven M.
Published: January 2024

Enzyme-linked immunosorbent assays for the detection of Toxoplasma gondii antigen-containing IgM immune complexes (T gondii-specific IgM-lC) and IgG immune complexes (T gondii-specific IgG-IC) in the serum of cats were developed. Serum from clinically ill, naturally infected cats; healthy, naturally infected cats; and healthy cats experimentally inoculated with T gondii was assayed. All combinations of T gondii-specific IgM, IgG, antigens, IgM-IC and IgG-IC were detected in naturally infected and experimentally infected cats. Clinically ill cats and cats with ocular signs of toxoplasmosis were more likely than healthy cats to have Tgondii-specific IC in serum. It was concluded that T gondii-specific IC form in the serum of cats, may play a role in clinical disease development, and affect the results of Tgondii-specific IgM, IgG, and antigen serologic assays.
Neuromuscular blockade by use of atracurium in anesthetized llamas
Authors: Hildebrand S. V. , Hill T.
Published: January 2024

Anesthesia was induced in 8 healthy llamas by administration of guaifenesin and ketamine, and was maintained with halothane in oxygen. On 2 separate experimental days, atracurium was given to induce 95 to 99% reduction of evoked hind limb digital extensor tension (twitch). For the first part of the study, atracurium was given IV as repeat boluses, with muscle twitch strength being allowed to return without intervention to 75% of baseline after each bolus before the subsequent bolus was given. A total of 5 bolus doses of atracurium was given. For the first bolus, 0.15 mg/kg of body weight IV, and for subsequent boluses, 0.08 mg/kg, induced desired relaxation. Onset of relaxation was slightly more rapid for repeat, compared with initial, bolus. Duration of relaxation and recovery time were similar to initial and repeat doses. Maximal twitch reduction was observed in 4 ± 0.2 minutes (mean ± SEM). Duration from maximal twitch reduction to 10% recovery was 6.3 ± 0.4 minutes. Twitch recovery from 10 to 50% of baseline took 11.6 ± 0.6 minutes. Twitch recovery from 10 to 75% recovery took 19.5 ± 1.1 minutes. Recovery from 10% twitch to 50% fade took 12.8 ± 0.5 minutes. Fade at 50% recovery of twitch was 39 ± 0.02%. Significant (P < 0.05) animal-to-animal variation was observed in twitch recovery times.

For the second part of the study, atracurium was initially given IV as a 0.15-mg/kg bolus, followed by infusion for 1 to 2 hours. Infusion rate required some early adjustment to maintain desired relaxation, but the rate that prevailed was 1.07 ± 0.07 ml/kg/h (0.4 mg of atracurium/ml of saline solution). Recovery of muscle twitch was similar to that previously mentioned for repeat bolus administration. At the end of the study, edrophonium (0.5 mg/kg) with atropine (0.01 mg/kg, IV) was effective in antagonizing residual neuromuscular blockade by atracurium. All llamas recovered without injury from anesthesia, although 1 llama had a rough recovery. It was concluded that atracurium can provide neuromuscular blockade by either repeat bolus administration or continuous infusion in llamas.
Effects of long-term administration of clenbuterol in mature female rats
Authors: Re Giovanni , Badino Paola , Dacasto Mauro , Nebbia Carlo , Biolatti Bartolomeo , Di Carlo Francesco , Girardi Carlo
Published: January 2024

Female Sprague-Dawley rats were treated IM with 0, 2.5, 25, and 50 μg of clenbuterol HCl/kg of body weight/d for 21 days. In all treated rats, significant increase in body weight gain (P < 0.05) and improvement in feed conversion ratio (P < 0.05) were recorded. Hydrometra was observed in the uterus of treated rats, and histologically, it was possible to see dilatation of luminal glands and ovarian alterations. Clenbuterol treatment induced significant (P < 0.05) increase in uterine estrogen receptor concentration of rats treated with the 2 higher doses. Treatment apparently failed to enhance the rate of oxidative and conjugative biotransformations, except for glucuronidation of p-nitrophenol (P < 0.05). On the basis of the data obtained, we could affirm that high doses of clenbuterol affect the female reproductive system of rats inducing, almost in part, estrogen-like modifications, but probably by a different mechanism of action correlated to intense adrenergic stimulation.
Effects on lung compliance, lung volume, and single-breath transfer factor for carbon monoxide in sheep with lentivirus-induced lymphoid interstitial pneumonia
Authors: Collie D. David S. , Watt Neil J. , Warren P. Μ. , Begara I. , Luján L.
Published: January 2024

Static lung compliance, static lung volumes, and transfer factor for carbon monoxide were measured in 12 anesthetized adult Texel ewes seropositive for maedi-visna virus (MVV) and in 11 breed-, sex-, and age-matched seronegative controls. Median static lung compliance in MVV-infected sheep (1.24 L⋅kPa−1; range, 0.27 to 2.20 L⋅kPa−1) was not significantly different from that in controls (1.58 L⋅kPa−1 range, 0.82 to 2.08 L⋅kPa−1). Median body weight of MVV-infected sheep (56 kg; range, 40 to 75 kg) was significantly (P < 0.05) less than that of controls (65 kg; range, 53 to 87 kg). Median effective alveolar lung volume in MVV-infected sheep (3.36 L; range, 1.44 to 4.52 L) was significantly (P < 0.01) less than that in controls (4.12 L; range, 3.75 to 4.90 L). Median effective end expiratory lung volume in MVV-infected sheep (1.20 L; range, 0.56 to 1.99 L) was significantly (P < 0.001) less than that of controls (1.98 L; range: 1.76 to 2.78 L). Median lung volumes expressed per unit of body weight did not differ significantly between the groups. Median single-breath transfer factor for carbon monoxide in MVV-infected sheep (7.89 mmol⋅min−1⋅kPa−1; range, 3.45 to 12.74 mmol⋅min−1⋅kPa−1) was significantly (P < 0.001) less than that in controls (14.10 mmol⋅min−1⋅kPa−1; range, 10.02 to 18.30 mmol⋅min−1⋅kPa−1). Median transfer factor expressed per liter of alveolar volume in MVV-infected sheep (2.44 mmol⋅min−1⋅kPa−1⋅L−1; range, 1.28 to 3.72 mmol⋅min−1⋅kPa−1⋅L−1) was significantly (P < 0.05) less than that in controls (3.22 mmol⋅min−1⋅kPa−1⋅L−l; range, 2.47 to 3.74 mmol⋅min−1⋅kPa−1⋅L−1). These findings indicate that static lung volumes and transfer factor for carbon monoxide are significantly decreased in adult sheep naturally infected with MVV.
Diagnosis of naturally acquired type-I and type-II diabetes mellitus in cats
Authors: Kirk C. A. , Feldman E. C. , Nelson R. W.
Published: January 2024

After IV administration of 0.5 mg of glucagon/cat, glucose tolerance and insulin secretory response were evaluated in 10 lean cats, 10 obese cats, and 30 cats with diabetes mellitus. Blood samples for glucose and insulin determinations were collected immediately before and at 5, 10, 15. 30, 45, and 60 minutes after IV administration of glucagon. Baseline serum insulin concentration and insulin secretory response were used to classify diabetes mellitus in the 30 cats as type I or type II.

Mean (± SEM) baseline and 30-minute serum glucose concentrations in obese cats were significantly (P < 0.05) decreased, compared with values in lean cats, but were similar at all other blood sample collection times. Serum glucose concentration in diabetic cats was significantly (P < 0.05) greater than values in obese and lean cats at all blood sample collection times. Two statistically different insulin responses to IV administration of glucagon were seen in diabetic cats. Of the 30 diabetic cats, 23 had minimal insulin secretory response after glucagon administration (ie, serum insulin concentration was at or below sensitivity of the insulin assay). Seven diabetic cats had baseline serum insulin concentration similar to that of obese cats and significantly (P < 0.05) greater than that of lean cats and of the other 23 diabetic cats. In these 7 diabetic cats, serum insulin concentration increased after glucagon administration. Total insulin secretion was not significantly different between these 7 diabetic cats and the lean and obese cats, and was significantly (P < 0.05) greater than total insulin secretion in the other 23 diabetic cats. Results support existence of type-I and type-II diabetes mellitus in cats.
Prevalence of mycoplasmal and ureaplasmal recovery from traceobronchial lavages and of mycoplasmal recovery from pharyngeal swab specimens in cats with or without pulmonary disease
Authors: Randolph J. F. , Moise N. S. , Scarlett J. M. , Shin S. J. , Blue J. T. , Corbett J. R.
Published: January 2024

The prevalence of mycoplasmal and ureaplasmal recovery from tracheobronchial lavage specimens and prevalence of mycoplasmal recovery from pharyngeal swab specimens from cats with (28) or without (18) pulmonary disease were determined. Mycoplasmas were recovered from tracheobronchial lavage specimens in 21% of cats with pulmonary disease, but in no cats without pulmonary disease; this difference is signficant (P = 0.04). Mycoplasmal recovery from tracheobronchial lavage specimens was not significantly associated with concurrent Pasteurella spp isolation, septic inflammation, or bronchitis. Ureaplasmas were only isolated from a tracheobronchial lavage specimen in 1 cat with pulmonary disease and in no cats without pulmonary disease. Similar mycoplasmal recovery rates were found for pharyngeal swab specimens from cats with (39%) or without (35%) pulmonary disease.

Seemingly, mycoplasmas are part of the normal pharyngeal flora in approximately a third of the feline population, but mycoplasmas are not normal inhabitants of the lower respiratory tract in cats. It is unknown whether mycoplasmas isolated from tracheobronchial lavage specimens in cats with pulmonary disease are primary pathogens or opportunistic invaders. Seemingly, ureaplasmas are seldom associated with pulmonary disease in cats, and are not normal inhabitants of the trachea and bronchi of cats.
Pharmacokinetics of digoxin administered to horses with congestive heart failure
Authors: Sweeney Raymond W. , Reef Virginia B. , Reimer Johanna M.
Published: January 2024

Nine horses with (naturally acquired) congestive heart failure were treated with 2.2 μg of digoxin/kg of body weight by the Iv route, followed by 11 μg/kg administered orally every 12 hours thereafter. Furosemide was administered IV concurrently with IV administered digoxin every 12 hours. Serum concentration of digoxin was measured after the first (Iv) and seventh (orally administered) dose.

After Iv administration, digoxin disposition was described by a 2-compartment model, with a rapid distribution phase (t1/2α = 0.17 hour), followed by a slower elimination phase (β = 0.096 ± 0.055 h−1, t1/2β = 7.2 hours, where β is the exponential term from the elimination phase of the concentration vs time curve). Bioavailability after oral administration was 21.2 ± 10.8%. After the seventh orally administered dose, serum concentration of digoxin peaked 1 to 2 hours later, and was 1.9 ± 0.7 ng/ml (mean ± sd). In 4 horses, a second increase in serum digoxin concentration was observed 4 to 8 hours after the initial peak, which possibly was evidence of enterohepatic recycling of the drug.

Response to treatment included reduction in heart rate, peripheral edema, and pulmonary edema, but these could not be attributed to the digoxin alone because the horses were treated concurrently with furosemide.
Ibuprofen treatment of endotoxin-induced mastitis in cows
Authors: DeGraves Fred J. , Anderson Kevin L.
Published: January 2024

Ibuprofen treatment was compared with saline solution treatment in an endotoxin-induced experimental model of bovine mastitis. Acute mastitis was induced in healthy lactating Holstein cows (n = 12) by intrammamary inoculation of 1 mg of Escherichia coli 026:B6 lipopolysaccharide in a single quarter per cow. Cows were assigned at random to ibuprofen (25 mg/kg of body weight, iv, n = 6) or 0.9% sodium chloride solution control (1.25 ml/kg, iv, n = 6) treatment groups. Ibuprofen or saline solution was administered once, 2 hours after endotoxin administration. The clinical course of endotoxin-induced mastitis and hematologic, clinical biochemical, and plasma mineral changes were monitored and compared between ibuprofen-treated and control cows. Clinical monitoring and blood sample collection were performed at 0, 2, 4, 6, 8, 12, 24, 48, 96, and 192 hours after endotoxin challenge.

Rectal temperature and heart and respiratory rates were significantly (P ≤ 0.05) increased in saline treated cows, compared with cows treated with ibuprofen. Blood eosinophil count and serum phosphorus, sodium, and total carbon dioxide concentrations were significantly (P ≤ 0.05) decreased in saline-treated cows, compared with cows treated with ibuprofen. Ibuprofen treatment did not significantly change ruminations per minute, electrical conductivity of milk, quarter size, or quarter inflammation. The remaining hematologic, serum biochemical, plasma mineral, and coagulation values also were not changed significantly in response to ibuprofen treatment. Untoward effects attributed to ibuprofen administration were not observed. These results indicate that ibuprofen may provide empiric relief of clinical signs of coliform-induced mastitis.
Inhibition of myelopoiesis by serum from dogs exposed to estrogen
Authors: Farris Georgia M. , Benjamin Stephen A.
Published: January 2024

The mechanism of estrogen-induced myelotoxicosis is unknown, although evidence indicates that estrogen does not directly damage the bone marrow granulocyte-macrophage progenitor cells and that the thymus is a probable mediator of the bone marrow suppression. Estrogen-induced production of a myelopoiesis-inhibitory factor by canine thymic stromal cells in vitro has been observed. Then, presence of a myelopoiesis-inhibitory factor in canine serum was investigated immediately after estrogen administration in vivo. Maximal reduction in colony-forming units-granulocyte/macrophage growth by sera from individual dogs varied. Individual dog sensitivity to estrogen-induced myelotoxicosis is seen clinically, and the cause is unknown. This serum factor could have a role in the eventual bone marrow hypoplasia seen in estrogen-treated dogs and is possibly the same factor produced by cultured thymic stromal cells exposed to estrogen.
Effect of preanesthetic medication on ease of endoscopic intubation of the duodenum in anesthetized dogs
Authors: Donaldson Lydia L. , Leib Michael S. , Boyd Christie , Burkholder William , Sheridan Michael
Published: January 2024

The effects of preanesthetic medication on ease of duodenal endoscopic intubation in dogs was evaluated. One of 12 combinations of preanesthetic medications (using atropine, glycopyrrolate, morphine, meperidine, acepromazine, and 0.9% NaCl solution) was administered im to each of 12 dogs in a trial. Twelve endoscopic trials were performed so that each dog received each treatment combination once. Anesthesia was induced with thiamylal administered iv and maintained with halothane vaporized in oxygen. Electrocardiographic recordings, indirect blood pressure measurements, end-tidal carbon dioxide partial pressures, and halothane concentrations were monitored during the anesthetic period. The ease with which the fiberoptic endoscope was passed into the proximal portion of the duodenum was qualitatively scored on the basis of time and maneuvering effort. None of the preanesthetic combinations made intubation of the duodenum significantly easier than that with 0.9% NaCl solution (control). Only the combmation of morphine and atropine induced gastropyloric conditions that resulted in significantly higher (more difficult) endoscopic scores than those after preanesthetic medication with 0.9% NaCl solution.
Production and characterization of VP4/VP7 reassortant swine rotaviruses derived from Gottfried and OSU parental strains
Authors: Hesse Richard A. , Couture Laurier P. , Ellsworth Steven R , Duhamel Gerald E. , Lu Wei , Dickinson Earl O. , Benfield David A.
Published: January 2024

The ability of viral glycoproteins (vp) vp4/vp7 reassortant swine rotaviruses (rv) to induce cross-neutralizing antibody against parental serotypes was investigated in guinea pigs. Using selective culture conditions, we produced 10 reassortant viruses that contained gene segment 4 of the OSU rv strain and gene segment 9 of the Gottfried rv strain. These reassortant rv grew to high titer in cell culture and were neutralized by monospecific antisera against both parental rv strains. The reassortant rv were chemically inactivated with binary ethylenimine, adjuvanted with aluminum hydroxide, and used to produce antisera in guinea pigs. The hyperimmune antisera had high neutralization titer against both parent rv strains. These results indicate that several of the reassortant rv may be capable of inducing neutralizing antibodies to vp4 and vp7 and may have future use as bivalent vaccine strains.
Effects of dietary protein and calorie restriction in clinically normal cats and in cats with surgically induced chronic renal failure
Authors: Adams Larry G. , Polzin David J. , Osborne Carl A. , O'Brien Timothy D.
Published: January 2024

To determine the effects of long-term dietary protein restriction in cats with chronic renal failure (crf), 4 healthy adult cats and 7 cats with surgically induced crf were fed a high-protein (hp, 51.7% protein) diet and 4 healthy adult cats and 7 cats with surgically induced crf were fed a low-protein (lp, 27.6% protein) diet for 1 year.

Cats with induced crf that were fed the lp diet had reduced serum urea nitrogen concentrations, despite lower glomerular filtration rates, compared with cats with crf fed the hp diet. Despite five-sixths reduction in renal mass, reduced glomerular filtration rate, and azotemia, 13 of the 14 cats with induced crf retained the ability to concentrate urine and produced urine with a specific gravity > 1.035.

Cats fed the hp diet consumed significantly more calories than did cats fed the lp diet, presumably because the hp diet was more palatable. As a result of the lower caloric intake in cats fed the lp diet, these cats were protein and calorie restricted, compared with cats fed the hp diet. Cats fed the hp diet weighed significantly more than did cats fed the lp diet. Mean hematocrit and mean serum albumin concentration were significantly lower in control cats and in cats with crf fed the lp diet, compared with control cats and cats with crf fed the hp diet.

Hypokalemia developed in 4 of 7 cats with crf fed the hp diet (containing 0.3% potassium); hypokalemia did not develop in control cats fed the same diet or in cats with crf fed the lp diet containing 0.4% potassium. Excessive kaliuresis, hypomagnesemia, and metabolic acidosis did not appear to contribute to the hypokalemia. Subsequent supplementation of the hp diet with potassium gluconate prevented hypokalemia in cats with crf.
Comparison of the effects on milk production of concurrent infection with Haemonchus contortus and Trichostrongylus colubriformis in high-and low-producing dairy goats
Authors: Hoste Herve , Chartier Christophe
Published: January 2024

The impact of nematode parasitism of the digestive tract on milk output and milk quality was examined in dairy goats. In addition, the consequences of worm infection were compared in goats with different lactation performance (ie, with initial high or low milk production). Forty-eight goats in the second month of lactation were allotted equally to 2 groups. The first group was given 5,000 Haemonchus contortus and 20,000 Trichostrongylus colubriformis larvae. The 24 additional goats remained free of parasites. Parasitologic, serologic, and milk data were collected every 2 weeks for 5 months, and body condition of the goats was scored throughout the study. Results of strongyle egg count in feces, increase in pepsinogen values, and reduction in RBC count, pcv, and serum inorganic phosphate concentration indicated subclinical infection. This subclinical parasitism induced a decrease in body condition scoring and led to persistent decrease in milk yield, ranging from 2.5 to 10% reduction from control values. Changes in fat and protein contents were not detected. In contrast, the consequences of infection were more severe in the 6 goats with the highest milk production at the start of the study. Decrease in milk output ranged between 13.0 to 25.1%, and was associated with decrease in fat content. Comparison of the response to parasitism in the 6 goats with the highest lactation performance and the 6 goats with the lowest performance indicated differences between both subgroups. According to parasitologic and pathologic data, high-producer goats had less resistance and/or resilience to infection associated with more severe consequences on milk production.
Altered platelet indices in dogs with hypothyroidism and cats with hyperthyroidism
Authors: Sullivan Patrick , Gompf Rebecca , Schmeitzel Lynn , Clift Rose , Cottrell Marilyn , McDonald T. P.
Published: January 2024

Changes in platelet indices (platelet count and platelet size) and pcv associated with thyroid disease were studied in 7 dogs with hypothyroidism and 21 cats with hyperthyroidism that were admitted to the veterinary teaching hospital. Compared with control (euthyroid) dogs, dogs with hypothyroidism had higher platelet count (P = 0.003), smaller platelet size (P = 0.01), and lower pcv (P = 0.02). Comparison of the group of hyperthyroid cats with a group of similarly aged, clinically normal cats with normal thyroxine values indicated that the group of hyperthyroid cats had significantly (P = 0.03) higher mean platelet size than did control cats, but differences were not found in mean platelet count or pcv. Results of this investigation indicate that the changes in platelet size reported in human beings with thyroid endocrinopathies also are found in animals so-affected. Although the pathogenesis of platelet abnormalities in animals with thyroid derangement is unclear and likely is multifactorial, the observed relation between platelet and erythrocyte production in this group of dogs is consistent with reports of an inverse relation between thrombocytopoiesis and erythropoiesis in iatrogenically hyperthyroid mice and in mice exposed to hypoxia.
Prevention of pathophysiologic and immunomodulatory effects of gastrointestinal nematodiasis in calves by use of strategic anthelmintic treatments
Authors: Yang C. , Gibbs H. C. , Xiao L. , Wallace C. R.
Published: January 2024

Effects of strategic anthelmintic treatment on pathophysiologic and immunomologic changes induced by infection with Ostertagia ostertagi and Cooperia oncophora were studied in 2 groups, of 12 calves each: an infected group, inoculated with 200,000 mixed O ostertagi and C oncophora third-stage larvae (L3) on day 1; and an infected-treated group, similarly inoculated, but treated with ivermectin at 9 and 33 days. All calves were also inoculated at 12 weeks with Brucella abortus vaccine, at 13 weeks with bovine rhinotracheitis vaccine (bovine herpesvirus 1), and at 14 weeks with a soluble O ostertagi L3 extract, then were allowed to graze on a contaminated pasture. Four calves from each group were slaughtered at 7, 11, and 19 weeks of the study.

Calves of the infected group had significantly (P < 0.05) lower weight gain than did those in the infected-treated group (60.90 kg vs 75.86 kg). They also had high plasma pepsinogen and serum gastrin values, and low serum albumin concentration from 2 or 4 weeks. Calves in the infected-treated group had steady weight gain and no significant changes in albumin and gastrin values. They also had less severe abomasal lesions and higher carcass yield.

Compared with calves of the infected-treated group, those of the infected group had significantly (P < 0.05) lower blood lymphocyte reactivity to phytohemagglutinin at 14 and 16 weeks, to concanavalin A at 10 weeks, to pokeweed mitogen at 14 weeks, and to soluble O ostertagi L3 extract at 2, 4, and 14 weeks. They also had significantly (P < 0.05) lower IgG1 concentration to excretory-secretory an tigens of the fourth-stage larvae of O ostertagi at 13, 18, and 19 weeks. In addition, they had significantly (P < 0.05) higher total mean eosinophil count. Antibody responses to B abortus and bovine herpesvirus 1, however, were not different between the 2 groups.
Alterations in the arrhythmogenic dose of epinephrine after xylazine or medetomidine administration in halothane-anesthetized dogs
Authors: Lemke Kip A. , Tranquilli William J. , Thurmon John C. , Benson G. John , Olson William A.
Published: January 2024

Eight dogs (12.5 to 21.5 kg) were assigned at random to each of 3 groups that were not given glycopyrrolate (hs, hx, hm) and to each of 3 groups that were given glycopyrrolate (hgs, hgx, hgm). Dogs were anesthetized with halothane (1.31% end-tidal concentration), and ventilation was controlled (PCO2 35 to 40 mm of Hg end-tidal concentration). Glycopyrrolate was administered iv and im at a dosage of 11 μg/kg of body weight, each. Saline solution, xylazine (1.1 mg/kg, im, or medetomidine (15 μg/ kg, im) was administered 10 minutes after baseline arrhythmogenic dose of epinephrine (ade) determination. Redetermination of the ade at the same infusion rate was started 10 minutes after drug administration. Arrhythmogenic dose was determined by constant infusion of epinephrine at rates of 1.0 and 2.5 μg/kg/min. The ade was defined as the total dose of epinephrine inducing at least 4 ectopic ventricular depolarizations within 15 seconds during a 3-minute infusion or within 1 minute after the end of the infusion. Total dose was calculated as the product of infusion rate and time to arrhythmia. Statistical analysis of the differences between baseline ade and posttreatment ade for groups hs, hx, and hm was performed by use of one-way anova. Mean ± sem baseline ade values for groups hs, hx, and hm were 1.50 ± 0.11, 1.49 ± 0.10, and 1.57 ± 0.22 pg/kg, respectively, and for groups hgs, hgx, and hgm were 3.37 ± 0.61, 3.10 ± 0.75, and 3.04 ± 0.94 pg/kg, respectively. Differences for groups hs, hx, and hm were – 0.02 ± 0.15, – 0.00 ± 0.14, and – 0.21 ± 0.17 μg/kg, respectively, and for groups hgs, hgx, and hgm, were – 0.59 ± 0.26, – 0.41 ± 0.15, and – 0.58 ± 0.20 μg/kg, respectively. Differences among groups hs, hx, and hm, or among groups hgs, hgx, and hgm were not significant. We conclude that without and with cholinergic blockade in halothane-anesthetized dogs: preanesthetic dosages of xylazine (1.1 mg/kg, im) or medetomidine (15 μg/kg, im) do not enhance arrhythmogenicity, and at these dosages, there is no difference in the arrhythmogenic potential of either α2-adrenoceptor agonist.
Low blood lead concentration associated with various biomarkers in household pets
Authors: Berny Philippe J. , Côté Louise M. , Buck William B.
Published: January 2024

A former secondary lead smelter was in operation in Granite City, Ill, until the early 1980s. As a result, the surrounding area is heavily contaminated with lead. Soil concentrations as high as 5,000 ppm have been measured in prior studies. Because of growing concerns about health defects associated with low levels of lead exposure in human beings, a major study has been conducted on people living in the area. The study reported here was a corollary to the human exposure study. Lead concentration was determined in 84 dogs and 26 cats in the town and ranged between < 5 and 28 μg/dl. None of the dogs had clinical signs of lead poisoning. The cbc and serum biochemical values did not indicate many significant differences between dogs with a high (> 10 μg/dl) or low blood lead concentration (blc). Hemoglobin concentrations were lower, and wbc counts were higher in dogs and cats with higher blc, but they were still within reference ranges. Free erythrocyte protoporphyrin concentration was determined. Normal values appeared to be similar for dogs and cats. Only animals with blc ≥ 20 μg/dl were found to have somewhat increased concentration of free erythrocyte protoporphyrin. ∂-Aminolevulinic acid dehydratase activity was measured and found to be negatively correlated with blc. The relation was strong, even at low blc (5 to 10 μg/dl) in both species. Age or sex difference was not observed. Therefore, biological changes associated with low blc were limited to blc in the 10- to 30-μg/dl range.
Effects of heparin, venous strangulation obstruction of the small intestine, and reperfusion of the small intestine on plasma diamine oxidase activity in horses
Authors: Laws Elizabeth G. , Freeman David E.
Published: January 2024

Diamine oxidase (dao), an enzyme of small intestinal origin, is released from mucosal storage sites by IV administration of heparin, to yield the plasma postheparin dao (phd) curve. The phd curve is diminished when mucosal surface area is lost, and baseline (without heparin) plasma dao activity increases when mucosal storage sites are damaged. Plasma dao activity was measured after 2 doses of heparin were administered iv in healthy, conscious horses. In anesthetized horses, the phd curve was studied: during sham small intestinal surgery, and during venous strangulation obstruction (vso) of the distal 50% of the small intestine. In a third group of anesthetized horses, baseline plasma dao activity (without heparin) was measured during vso of the distal 50% of the small intestine for 90 minutes, followed by reperfusion for 90 minutes.

Postheparin plasma dao curves in conscious horses were similar to those reported in other species. Horses with vso had a similar phd curve as did sham-operated controls at all times, except at 15 minutes, when plasma dao activity was significantly (P < 0.05) greater in the vso group. Horses with vso and reperfusion had no change in baseline plasma dao activity throughout the study. Peritoneal fluid dao activity remained low throughout the study, but increased slightly in horses with vso that received heparin, possibly because of dao from extravasated blood in the peritoneal fluid.

Results indicated that the plasma dao response to iv administered heparin in horses is similar to that in other mammals, but, unlike other species, baseline and postheparin dao activities did not change as expected after small intestinal vascular obstruction and mucosal injury. There may be additional sources of dao in horses, the type of injury induced was not of sufficient magnitude to affect storage sites of dao, or the circulatory changes induced by vso might have altered tissue delivery of heparin.