bluuebunny/crossref_metadata_2025 huggingface dataset:
Resistance to antimicrobial agents and prevalence of R plasmids in Pasteurella multocida from swine
Authors: Coté Sandra , Harel Josée , Higgins Robert , Jacques Mario
Published: January 2024

Twenty-nine field isolates of porcine Pasteurella multocida were characterized for their capsular and somatic types and were evaluated for their susceptibility to 10 antimicrobial agents. Plasmid dna-screening experiments were conducted to determine whether a relationship existed between the presence of plasmids and antibiotic resistance. Field isolates of P multocida were susceptible to most of the antimicrobials tested, but all isolates were resistant to clindamycin. Eleven isolates of serogroup D were resistant to 1 or 2 antimicrobial agents. Resistance to sulfonamides and streptomycin was observed in 7 isolates. These isolates contained R plasmids conferring resistance to streptomycin and sulfonamides. The R plasmids belonged to 2 groups, one of 5.6 kilobase and the other of 5.9 kilobase. Restriction endonuclease mapping and dna hybridization revealed that these R plasmids were related to RSF1010 from Salmonella panama, which also confers resistance to streptomycin and sulfonamides.
Mass screening of cattle sera against 14 infectious disease agents, using an ELISA system for monitoring health in livestock
Authors: Behymer D. E. , Riemann H. P. , Utterback W. , D-Elmi C. , Franti C. E.
Published: January 2024

Mass screening elisa methods were developed for testing cattle serum for antibodies against 14 common livestock diseases simultaneously. The absorbance values were transformed to a %elisa (spectrophotometric antibody end point) by a computer interfaced with a microplate reader. A histogram indicating a cutoff point and a report for the veterinarian also was generated. The computer program produced a print-out of the antibody profile for each animal tested, the antibody concentration against each disease, and a histogram (antibody profile) showing the prevalence of each disease in the herd. Serum samples were obtained from 1,953 cattle, including 880 dairy cattle from 10 herds and 1,073 beef cattle from 20 herds. These samples were obtained from June 1988 through June 1989. The highest antibody prevalence was against bluetongue virus. Of the 1,953 cattle tested, 1,223 (63%) were seropositive for bluetongue virus, including 502 (57%) of the dairy cattle and 721 (67%) beef cattle. Other antibody prevalences, in descending order, were: rotavirus (44%), Pasteurella spp (25%), Leptospira spp and Haemophilus spp (22%), Mycoplasma spp (18%), parainfluenza virus (17%), Campylobacter spp (16%), Anaplasma marginale (15%), bovine leukosis virus (13%), Brucella spp (8%), Mycobacterium paratuberculosis (8%), bovine viral diarrhea virus (3%), and infectious bovine rhinotracheitis virus (3%). Major differences in antibody prevalence between dairy and beef cattle were that only 4% of the dairy cattle were seropositive for A marginale, compared with 25% of the beef cattle, and conversely, 29% of the dairy cattle were seropositive for bovine leukosis virus, compared with 1% of the beef cattle. Further development of the elisa is advocated for mass screening of livestock sera for the application in epidemiologic methods for disease control in food animals.
Multivariable prediction model for the need for surgery in horses with colic
Authors: Reeves Mathew J. , Curtis Charles R. , Salman Mo D. , Stashak Ted S. , Reif John S.
Published: January 2024

A survey of 1,965 equine colic cases was conducted from August 1985 to July 1986 at 10 equine referral centers located throughout the United States. The purpose of this study was to develop and validate a multivariable model for the need for surgery. Two-thirds of the cases were randomly selected for model development (1,336), whereas the remaining cases (629) were used only for subsequent validation of the model. If a lesion requiring surgical correction was found at either surgery or necropsy, the case for the horse was classified as surgical, otherwise the case was classified as medical. Only variables that were significant (P < 0.05) in an initial bivariable screening procedure were considered in the model development. Because of the large number of missing values in the data set, only variables for which there were < 400 missing values were considered in the multivariable analysis. A multivariable logistic regression model was constructed by use of a stepwise algorithm. The model used 640 cases and included variables: rectal findings, signs of abdominal pain, peripheral pulse strength, and abdominal sounds. The likelihood ratio for surgery was calculated for each horse in the validation data set, using the logistic regression equation. Using Bayes theorem, the posttest probability was calculated, using the likelihood ratio as the test odds and the prevalence of surgery cases (at each institution) as an estimate of the pretest odds. A Hosmer-Lemeshow goodness-of-fit χ2 statistic indicated that the model fit the validation data set poorly, as demonstrated by the large χ2 value of 26.7 (P < 0.001). However, when the expected proportion of surgical cases was compared with the observed proportion of surgical cases in each of 10 increments of risk, the model's performance appeared satisfactory.
Evaluation of atropine, glucagon, and metoclopramide for facilitation of endoscopic intubation of the duodenum in dogs
Authors: Matz Michael E. , Leib Michael S. , Monroe William E. , Davenport Deborah J. , Nelson Laura P. , Kenny James E.
Published: January 2024

Modification of gastroduodenal motility has been proposed to aid endoscopic examination of the duodenum in dogs. The objective of this study was to evaluate the use of the following pharmacologic agents for facilitation of endoscopic intubation of the duodenum in 6 clinically normal dogs: metoclopramide HCl (0.2 mg/kg of body weight), atropine sulfate (0.045 mg/kg), glucagon (0.06 mg/kg), and isotonic saline solution.

In a randomized, blinded, crossover design, the ease of endoscopic duodenal intubation was qualitatively scored by 3 endoscopists (in random order), using the following scale: immediate entry; rapid entry—moderate manipulation; difficult entry—multiple attempts; and no entry after 2 minutes. Anesthesia was induced with thiopental and maintained with halothane. The 4 agents were diluted to a fixed volume and randomly administered. Duodenal intubation was attempted 2 minutes after iv injection of 1 of the agents. Four endoscopic procedures (1 for each agent) were performed on each dog with a minimum of 5 days between each procedure.

In this study, no agent facilitated endoscopic duodenal intubation at the dose used. Instead, atropine and metoclopramide made duodenal intubation significantly more difficult, compared with use of saline solution. Difference between intubation after administration of glucagon and saline solution was not seen. On the basis of our findings, the use of these agents for facilitating endoscopic duodenal intubation is not recommended.

In addition, in this study, we found that experience in endoscopic intubation is an important factor in determining the ease of duodenal intubation.
Serum liver enzyme and histopathologic changes in calves with chronic and chronic-delayed Senecio jacobaea toxicosis
Authors: Craig A. M. , Pearson E. G. , Meyer C. , Schmitz J. A.
Published: January 2024

Progressive changes in serum enzyme activity and liver histologic features were monitored in calves fed tansy ragwort (Senecio jacobaea)-contaminated pellets. The experiments were designed to simulate natural intoxicant ingestion conditions in relationship to the dose and duration of exposure to the toxic plant to correlate early laboratory diagnostic changes with the natural progression of the disease, thereby facilitating early diagnosis and intervention by veterinary clinicians. Eight calves were fed tansy ragwort and 4 additional calves served as controls. In group 1, 4 calves were continuously fed dried tansy ragwort mixed in a pelleted feed at a 5% concentration by dry weight until terminal liver disease developed. Serum liver enzyme (alkaline phosphatase, glutamate dehydrogenase, and γ-glutamyltransferase) activities were monitored at weekly intervals in these calves and in the 2 controls. In group 2, 4 calves were fed the same contaminated feed for only 60 days, with return to normal feed for the duration of the trial. Two additional calves served as controls. Their liver enzyme activities were monitored every other week in conjunction with percutaneous liver biopsies.

All 8 calves fed tansy ragwort-contaminated pellets developed terminal hepatopathy in either a chronic pattern (n = 6) or a chronic-delayed pattern (n = 2), with the onset of a moribund state or sudden death at 11 to 17 weeks and 27 to 51 weeks, respectively. The calves were euthanatized when classic terminal signs of hepatic encephalopathy first became evident. The clinicopathologic patterns of chronic and chronic-delayed toxicoses were typical of over 5,000 cases of field tansy toxicosis diagnosed at the diagnostic laboratory. Serum glutamate dehydrogenase was the first enzyme to increase in most animals, with a short-term increase to peak values followed by a rapid return to normal. This enzyme change was followed by increases in alkaline phosphatase and γ-glutamyltransferase. Serum enzyme changes preceded development of recognizable histologic lesions. Vacuolar changes in hepatocyte nuclei, biliary hyperplasia, and fibrosis sequentially developed in liver biopsy specimens from each animal, whereas megalocytosis was not a predominant feature until necropsy. On the basis of our findings, we suggest that the optimal tests for diagnosis of pyrrolizidine alkaloid intoxication should consist of liver biopsy and determination of concurrent serum liver-enzyme activities.
Platelet function, antithrombin-III activity, and fibrinogen concentration in heartworm-infected and heartworm-negative dogs treated with thiacetarsamide
Authors: Boudreaux M. K. , Dillon A. R.
Published: January 2024

Platelet aggregation and release, platelet number, mean platelet volume, antithrombin-III activity, and fibrinogen concentration were evaluated in heartworm-negative and heartworm-infected dogs at baseline and on days 3, 10, and 21 after treatment with thiacetarsamide.

Platelet reactivity was enhanced in a group of dogs naturally infected with Dirofilaria immitis, compared with 2 groups of heartworm-negative dogs, but platelet reactivity was not further enhanced after treatment with thiacetarsamide. A significant decrease in antithrombin-III activity was detected 21 days after treatment.

The platelets from a group of laboratory Beagles implanted with 50 adult D immitis displayed enhanced reactivity 6 months after implantation, but by 18 months, platelet reactivity had returned to near, or less than, baseline. Platelet reactivity was enhanced after thiacetarsamide treatment in this group. Thiacetarsamide-associated changes were not observed in platelet number or size; antithrombin-III activity decreased, but the change was not significant. Fibrinogen concentration was increased significantly (P < 0.05) on day 10.

Enhanced adenosine diphosphate (adp)-induced platelet aggregation was observed on days 3, 10, and 21 after treatment in heartworm-negative dogs. This change was not observed in 6 control Beagles not treated with thiacetarsamide. Although antithrombin-III activity was decreased on day 3 and fibrinogen concentration was increased on day 10, paralleling changes observed in the heartworm-infected dogs, the changes were not statistically significant.

In this study, thiacetarsamide was procoagulatory in heartworm-negative dogs and may be an important contributing factor to the thromboembolism observed with adulticidal therapy.
Effects of treatment with ticlopidine in heartworm-negative, heartworm-infected, and embolized heartworm-infected dogs
Authors: Boudreaux Mary K. , Dillon Allen R. , Sartin Eva A. , Ravis William R. , Spano Joseph S.
Published: January 2024

Ticlopidine hydrochloride was evaluated for its effectiveness in inhibiting platelet aggregation and serotonin release in 5 laboratory Beagles before and after heart-worm implantation with 7 adult Dirofilaria immitis, and after embolization with 7 dead heartworms to mimic what happens after heartworm adulticide treatment. Five other laboratory Beagles, similarly implanted and embolized with heartworms, were used as nonmedicated controls. During the heartworm-negative stage, the dosage of ticlopidine that inhibited adenosine diphosphate (adp)-induced platelet aggregation in 5 dogs by at least 50% after 5 days of treatment was 62 mg/kg of body weight once a day. In the same dogs implanted with 7 adult heartworms 21 days previously, mean (± sd) ticlopidine dosage required to obtain similar results was 71 (± 13) mg/kg given once daily. During the 21 days after dead heartworms were implanted in heartworm-infected dogs, mean ticlopidine dosage was 108 (± 35) mg/kg (range, 62 to 150 mg/kg). Ticlopidine treatment was associated with increased platelet numbers in all 5 dogs during the heartworm-negative stage and in 4 of 5 dogs during the heartworm implantation and heartworm embolization stages. Mean platelet volume tended to decrease as platelet numbers increased. At necropsy, gross and histologic pulmonary lesions were less severe in ticlopidine-treated dogs than in nonmedicated control dogs.
Prophylactic and therapeutic effects of phosphonoformate against feline leukemia virus in vitro
Authors: Swenson Cheryl L. , Polos Phyllis J. , Cheney Carolyn M. , Kociba Gary J. , Mathes Lawrence E.
Published: January 2024

Phosphonoformate (pfa), a noncompetitive inhibitor of reverse transcriptase (rt), inhibited feline leukemia virus (FeLV) infection of 2 feline cell lines and inhibited progeny virus rt activity in a chronically FeLV-infected cell line. Feline leukemia virus infection of 3201 cells, an FeLV-negative lymphoma cell line, was inhibited by > 70% at a concentration of only 1 μM pfa and by > 90% at concentrations of 64 to 256 μM pfa, as evidenced by rt activity. However, FeLV antigen expression by 3201 cells remained relatively constant over noncytotoxic concentrations of pfa. Because the persistence of viral antigen expression with concomitant suppression of rt activity appears to be unique and because 3201 cells express small amounts of an endogenous retrovirus (RD-114) and contain endogenous FeLV proviral sequences, a possible role of endogenous retroviruses acting as helper viruses was suggested. Feline leukemia virus infection of 81C cells, a sarcoma-positive, leukemia-negative fibroblast cell line, was inhibited by > 50% at a concentration of 64 μM pfa and by > 98% at concentrations of 256 to 512 μM pfa, as indicated by suppression of focus formation. The feline lymphoid cell line FL-74 is a large producer of FeLV. When FL-74 cells were cultured in the presence of 256 μM pfa, virus production (virus budding and viral antigen) was not affected, but progeny virus lost rt activity and infectivity. Direct addition of pfa (256 μM) to FeLV also reduced rt activity and infectivity. These data indicate that pfa can directly and rapidly inactivate retrovirus independent of cellular processing, presumably by inhibiting rt. Long-term pfa administration may curtail spread of retroviral infections within and between hosts via extracellular inactivation of newly produced virus particles. Results of this study also suggest that pfa might be used prophylactically to treat materials potentially contaminated with retroviruses.
Absorption of an alternate source of immunoglobulin in pups
Authors: Bouchard Guy , Plata-Madrid Hernando , Youngquist Robert S. , Buening Gerald M. , Ganjam Venkataseshu K. , Krause Gary F. , Allen Gary K. , Paine Allyson L.
Published: January 2024

Newborn pups from 4 large litters were allotted to 6 groups to determine effect of time and route of administration on absorption of an alternate source of immunoglobulin. Selective absorption of specific classes of immunoglobulins was also investigated. The alternate source of immunoglobulin consisted of pooled serum that was administered either po or sc. Control groups were either left with the dam (group C1) or fed milk replacer (group C2). Blood samples were collected from pups at birth and 24 hours. Immunoglobulin (IgA, IgG, IgM) concentrations were determined by use of radial immunodiffusion on samples of pooled serum, colostrum, and pups’ serum (birth and 24 hours).

Serum IgA concentration was less than the sensitivity of the procedure and was not included in the statistical analysis. Pups fed 8 ml of pooled serum at birth and 12 hours later (group T1) absorbed more (P< 0.05) IgG and IgM than did group-C2 pups, but less (P < 0.05) than did group-C1 pups. Pups fed 8 ml of pooled serum at 12 hours only had significant (P < 0.05) increase of IgG concentration, but no absorption of IgM (P > 0.05) at 24 hours, compared with control pups (group C2). Pups administered 8 ml of pooled serum SC at birth (group SC1) had similar (P > 0.05) absorption of IgG and higher (P < 0.05) absorption of IgM than did pups of group T1. Pups administered 16 ml of pooled serum sc at birth had the highest increase of IgG and IgM concentrations of all treatment groups, but immunoglobulin concentrations were lower (P < 0.05) than those for group-C1 pups. Absorption of IgG was favored, compared with IgM, when pooled serum was fed.

Results indicate clearly that intestinal absorption of immunoglobulins is minimal after 12 hours and thus, another route of administration should be used. Pups in groups SC1 and T1 had similar absorption of IgG, despite lower IgM absorption in pups of group T1. This lower IgM concentration in group-T1 pups may have been the result of selective intestinal absorption or the consequence of low number of pups per group. Subcutaneous administration of 16 ml of pooled serum was the most successful alternative to colostrum, with minimal pain to pups if serum was administered slowly. Serum IgG concentration in Cl pups was higher than expected and probably was attributable to the amount of colostrum available to the pups.
Furcation anatomy of the first mandibular molar in dogs
Authors: Smith Mark M. , Massoudi Lisa M. , Nunes Jack D. , McCain Wilfred C.
Published: January 2024

Tooth surface and interradicular area (furcation) measurements were taken of 20 first mandibular molar teeth obtained randomly from canine cadavers. The lingual furcation entrance had a mean width of 1.2 ± 0.3 mm. The buccal furcation entrance had a mean width of 1.3 ± 0.4 mm. There was no significant difference between mean furcation entrance measurements. The horizontal attachment area between the cementoenamel junction and the coronal roof of the lingual furcation was 1.1 ± 0.4 mm. The horizontal attachment area between the cementoenamel junction and the coronal roof of the buccal furcation (0.5 ± 0.3 mm) was significantly different from the lingual horizontal attachment area. Distal root length and mesial root length were 16.0 ± 1.5 mm and 16.1 ± 1.6 mm, respectively. The mean coefficient of variation for variables measured was 14.0%. Tooth size did not have a significant effect on furcation entrance measurement. All teeth had a concavity coronal to the furcation area, which extended apically for a mean distance of 65.6% of the distal root length and 83.8% of the mesial root length. Furcation anatomy of the first mandibular molar is complex and may be a contributing factor in periodontal disease involving the interradicular area.
Epidemiologic factors involved in perinatal lamb mortality on four range sheep operations
Authors: Rowland J. P. , Salman M. D. , Kimberling C. V. , Schweitzer D. J. , Keefe T. J.
Published: January 2024

Four shed-lambing operations in western Colorado were monitored during the 1984 spring lambing season to determine the causes and rates of perinatal lamb mortality. The number of lambing ewes per flock ranged from 513 to 1,712, and lambing percentages ranged from 131 to 180%. Overall perinatal lamb mortality ranged from 8.2 to 12.2%. Most lamb deaths occurred during parturition or within 24 hours after parturition. More than 85% of all lamb deaths were in lambs born to ewes having 2 or more lambs. The leading causes of lamb death were starvation, dystocia, stillbirth (unknown cause), and infectious diseases. A wheel model was used to categorize factors causing lamb deaths into 4 groups: physical, social, host, and biological, and to present data on perinatal lamb mortality in a simple visual model. In all flocks, social and biological factors resulted in most of the lamb deaths. On the basis of our findings, we suggest that interventions designed to improve ewe-lamb bonding and to reduce infectious agents and the incidence of prolonged parturition may reduce lamb mortality.
Fungal flora of the healthy camelid conjunctival sac
Authors: Gionfriddo Juliet R. , Gabal Moustafa A. , Betts Daniel M.
Published: January 2024

Swab specimens for fungal isolation were collected from the healthy conjunctival sacs of 3 species of captive camelids (Lama glama, L guanicoe, L pacos) and llamaguanaco hybrids. Fungi were collected from over half the animals in winter (53%) and summer (56%). Fungal species of 10 genera were isolated. In both seasons, Aspergillus was the most commonly isolated genus; at least 9 species of Aspergillus were found. The fungal organisms isolated were similar to those found in healthy eyes of other domestic animals and may represent a random seeding from the environment where they are ubiquitous.
Effects of lithium carbonate administration to healthy cats
Authors: Dieringer Therese M. , Brown Scott A. , Rogers Kenita S. , Lees George E. , Whitney Marlyn S. , Weeks Brad R.
Published: January 2024

Lithium carbonate administration to healthy cats was evaluated in 2 controlled studies (a dose-response study and a bone marrow evaluation study) to determine the effectiveness of lithium as a bone marrow stimulant. Lithium carbonate was administrated at dosage ranging from 300 to 1,050 mg/m2 of body surface/d. Complete blood count, serum lithium concentration determination, serum biochemical analysis, urinalysis, and bone marrow aspiration and biopsy were periodically performed.

Serum lithium concentration > 2 mEq/L was associated with significant decrease in numbers of circulating segmented neutrophils (< 1,200 cells/μl; P < 0.01) and lymphocytes (< 1,300 cells/μl; P < 0.0001), as well as significant (P < 0.05) decrease in urine specific gravity. Bone marrow evaluation revealed apparent maturation arrest of the neutrophil cell line.

Coincident with the changes in laboratory values, the lithium-treated cats became ill. Changes in behavior and vocalization were seen, followed by anorexia, vomiting, and diarrhea. In later stages of intoxication, cats became hyperexcitable and manifested coarse muscular tremors. It was concluded that lithium carbonate does not have potential value as a bone marrow stimulant and is toxic to cats at serum concentration > 2 mEq/L.
Effect of hyaluronidase on aqueous outflow resistance in normotensive and glaucomatous eyes of dogs
Authors: Gum Glenwood G. , Samuelson Don A. , Gelatt Kirk N.
Published: January 2024

The anterior chambers in 16 dogs with normotensive eyes and 3 Beagles with glaucomatous eyes were treated with 0, 25, 50, or 100 IU of bovine testicular hyaluronidase. Aqueous outflow resistance was then determined by constant-pressure perfusion of 0.9% NaCl solution for 30 or 60 minutes. In normotensive eyes, 25, 50, or 100 IU of hyaluronidase significantly (P < 0.02) increased the rate of constant-pressure perfusion compared with that of untreated eyes during 30- or 60-minute perfusions. Treatment of glaucomatous eyes with 25, 50, or 100 IU of hyaluronidase did not significantly increase the rate of constant-pressure perfusion over controls during a 30-minute perfusion.

Bovine testicular hyaluronidase at all doses removed the staining of colloidal iron from the trabecular meshwork in normotensive eyes. In Beagles with glaucoma, the trabecular meshworks remained stained with colloidal iron when treated with the hyaluronidase, which suggested that some glycosaminoglycans were resistant to this enzyme's action.
In vitro comparison of equine granulocytes labeled with 99mTc-hexamethylpropyleneamine oxime or 111In-oxine
Authors: Daniel Gregory B. , Tucker Russell L. , Buckman Theresa , Daniel Sandra L.
Published: January 2024

Isolated equine granulocytes (wbc), radiolabeled with 99mTc-hexamethylpropyleneamine oxime (99mTc-hmpao) or 111In-oxine, were evaluated in vitro for their labeling characteristics, viability, and phagocytic function over a 6-hour postlabeling period. Mean ± sd labeling efficiency for 111In-oxine-wbc was 62.2 ± 15.3%, which was significantly (P < 0.001) higher than that for 99mTc-hmpao-wbc (32.0 ± 17.0%). In vitro elution of radiolabel from cells was significantly (P < 0.02) greater for 99mTc-hmpao-wbc at 0.5, 2, and 4 hours, but was not significantly different from elution of radiolabel for 111In-oxine-wbc at 6 hours. Viability, assessed by trypan blue dye exclusion, for 99mTc-hmpao-wbc, 111In-oxine-wbc, and nonlabeled control wbc ranged from 97 to 100%, and was not significantly different among groups. Cell function was assessed by use of a phagocytosis assay and was reported as phagocytic index. The phagocytic index ranged from 0.86 to 0.96 for 99mTc-hmpao-wbc, and from 0.76 to 0.97 for 111In-oxine-wbc. The phagocytic index was not significantly different at 0.5, 2, or 4 hours, but was significantly (P = 0.038) greater at 6 hours for 99mTc-hmpao-wbc. Because of the superior imaging characteristics of 99mTc-hmpao-wbc and equal or better labeling characteristics than those for 111In-oxine at 6 hours, 99mTc-hmpao-wbc appear to be a good alternative to 111In-oxine-wbc.
Use of tissue plasminogen activator for intraocular fibrinolysis in dogs
Authors: Gerding Paul A. , Essex-Sorlie Diane , Vasaune Steven , Yack Robert
Published: January 2024

Fibrin clots were induced in eyes of dogs by injection of autogenous citrated plasma into the anterior chamber. Twenty-four hours after clot formation, 0.01 ml of tissue plasminogen activator at a concentration of 1 μg/100 μl (group 1, n = 5) or 25 μg/100 μl (group 2, n = 5) was injected into 1 anterior chamber of each dog. The contralateral eye served as a nontreated control. Serial photographs were taken of the fibrin clots after intracameral injection of tissue plasminogen activator. Computerized morphometric analysis was then used to evaluate changes in cross-sectional surface area of the fibrin clot. Significant (P < 0.001) fibrin-clot lysis was detected in treated eyes of group-2 dogs, but was not found in treated eyes of group-1 dogs. A mean decrease of > 90% in clot surface area was detected by 120 minutes after injection in treated eyes of group-2 dogs.
Anti-equine tumor necrosis factor (tnf) activity of antisera raised against human tnf-α and peptide segments of human tnf-α
Authors: MacKay Robert J. , Socher Susan H.
Published: January 2024

Antisera raised in rabbits against either purified recombinant-derived human tumor necrosis factor (tnf)- α (hutnf) or hutnf peptide-bovine thyroglobulin conjugates were evaluated for anti-equine tnf (eqtnf) activity. Binding and neutralizing anti-eqtnf activities were found in antisera raised against whole hutnf or against either of the peptides containing the N-terminal 15 amino acids of hutnf (hutnf[1-15] and hutnf[1-31]). Anti-eqtnf activity was not detected in antisera raised against hutnf[65-79], hutnf[98-111] or hutnf[124-141] peptides. The addition of excess hutnf[1-15] completely inhibited the ability of anti-hutnf[1-15] to bind eqtnf and reduced by approximately 25% the anti-eqtnf activity of an antiserum raised against whole hutnf. Nonconjugated hutnf[1-15] did not have eqtnf agonist or antagonist activity. Results were consistent with previous structural and functional data implicating the N-terminus of hutnf in receptor binding and indicate that the homologue of hutnf[1-15] on eqtnf may be a potentially important target for neutralizing anti-eqtnf antibodies.
Effects of prostaglandin F2α and leukotriene D4 on pupil size, intraocular pressure, and blood-aqueous barrier in dogs
Authors: Dziezyc Joan , Millichamp Nicholas J. , Keller Charlotte B. , Smith William B.
Published: January 2024

In each of 5 groups of dogs, 0.05 ml of 1 of the following solutions was injected into the anterior chamber of both eyes: phosphate-buffered saline solution, 0.001 μg of prostaglandin F2α (pgf2α), 0.01 μg of pgf2α, 0.1 μg of leukotriene D4(ltd4), and 1 μg of ltd4. A 10% solution of sodium fluorescein was injected iv (14 mg/kg of body weight) at the same time, and pupil size, intraocular pressure, and anterior chamber fluorescence were measured for 1 hour after injections. In a dose-dependent manner, pgf2α was a potent miotic. A significant effect on intraocular pressure was not detected when the groups given pgf2α were compared with the control group. When compared with ltd4, pgf2α significantly (P < 0.05) increased the breakdown of the blood-aqueous barrier, as evidenced by increased fluorescein leakage into the anterior chamber. Leukotriene D4 caused a decrease in pupil size only at 5 minutes, compared with that of the control group. Intraocular pressure was greater (but not significantly) in the group given 1 μg of ltd4.
Susceptibility of dogs to infection with Ehrlichia chaffeensis, causative agent of human ehrlichiosis
Authors: Dawson Jacqueline E. , Ewing S. A.
Published: January 2024

Ehrlichia chaffeensis, the newly recognized agent of human ehrlichiosis, is closely related to E canis, the causative agent of canine ehrlichiosis. Eight pups were inoculated iv with E chaffeensis-, or with E canis-infected DH82 cells, or organisms released from these host cells. Two additional pups served as nonexposed controls. Marked thrombocytopenia was observed in the E canis-infected pups, but not in those infected with E chaffeensis. Homologous serologic response was observed in the E chaffeensis-exposed pups by postinoculation day (pid) 14 and in the E canis-exposed pups by pid 21. Ehrlichia chaffeensis and E canis were reisolated from the respective inoculated pups on each of 8 attempts from pid 7 to 26. One E chaffeensis-exposed pup that was challenge exposed with E canis via blood transfusion, developed fever, anorexia, and thrombocytopenia, suggesting lack of cross protection against E canis.
Comparison of intravenous and intramuscular routes of administering cosyntropin for corticotropin stimulation testing in cats
Authors: Peterson Mark E. , Kemppainen Robert J.
Published: January 2024

Plasma cortisol and immunoreactive (ir)-acth responses to 125 μg of synthetic acth (cosyntropin) administered iv or im were compared in 10 clinically normal cats. After im administration of cosyntropin, mean plasma cortisol concentration increased signficantly (P < 0.05) within 15 minutes, reached maximal concentration at 45 minutes, and decreased to values not significantly different from baseline concentration by 2 hours. After iv administration of cosyntropin, mean plasma cortisol concentration also increased significantly (P < 0.05) at 15 minutes, but in contrast to im administration, the maximal cortisol response took longer (75 minutes) and cortisol concentration remained significantly (P < 0.05) higher than baseline cortisol concentration for 4 hours. Mean peak cortisol concentration (298 nmol/L) after iv administration of cosyntropin was significantly (P < 0.05) higher than the peak value (248 nmol/L) after im administration. All individual peak plasma cortisol concentrations and areas under the plasma cortisol response curve were significantly (P < 0.05) higher after iv administration of cosyntropin than after im administration. Mean plasma ir-acth concentration returned to values not statistically different from baseline by 60 minutes after im administration of cosyntropin, whereas ir-acth concentration still was higher than baseline concentration 6 hours after iv administration. Peak plasma ir-acth concentration and area under the plasma ir-acth response curve also were significantly (P < 0.05) higher after iv administration of cosyntropin. Results of the study confirmed that iv adminstration of cosyntropin induces significantly (P < 0.05) greater and more prolonged adrenocortical stimulation than does im administration. The reason for this greater degree of stimulation of the adrenal cortex is presumably the result of the higher circulating acth concentration attained by iv, compared with im, administration.
Identification and categorization of the vascular patterns to muscles of the thoracic limb, thorax, and neck of dogs
Authors: Purinton P. Thomas , Chambers Jonathan N. , Moore James L.
Published: January 2024

Vascular patterns to thoracic limbs, thorax, and neck muscles were studied in 10 dogs (20 limbs) to identify muscles most suitable for transposition in the treatment of large wounds. Gross dissection of injected specimens and angiography were used to identify vascular pedicles. Size and location of pedicles were generally consistent, and any variations would not interfere with most muscle transfers. The cutaneous trunci, latissimus dorsi, sternothyroideus, sternohyoideus, deep pectoral, anconeus, ulnaris lateralis, and ulnar head of flexor carpi ulnaris muscles were identified as suitable for transfer. The cranial trapezius, caudal omotransversarius, cleidobrachialis, and caudal sternocephalicus muscles also had potential for use. Other muscles, because of inaccessibility or unfavorable vascular pattern, were not suitable candidates for transfer.
Invasion of enterocytes in cultured porcine small intestinal mucosal explants by Salmonella choleraesuis
Authors: Nietfeld Jerome C. , Tyler David E. , Harrison Lenn R. , Cole John R. , Latimer Kenneth S. , Crowell Wayne A.
Published: January 2024

Porcine small intestinal explants maintained in vitro were inoculated with Salmonella choleraesuis to study the characteristics of its invasion of enterocytes. The explants were fixed at selected intervals for up to 12 hours after inoculation and examined by conventional light microscopy, immunoperoxidase staining, and transmission electron microscopy. Although there was diffuse loss of villous enterocytes during the first hour of incubation, the villi were reepithelialized by the end of 2 hours of culture, and the mucosal epithelium remained intact and appeared to be viable through 12 hours of culture. Intraepithelial S choleraesuis were not detected before 6 hours after inoculation, but after 12 hours of incubation, bacteria were numerous within enterocytes. Ultrastructurally, penetration of the brush border by S choleraesuis resulted in focal loss of microvilli. Bacteria were endocytosed into membrane-bound vacuoles where most remained, but a few were free within the cytoplasm of enterocytes. Invasion of the explants closely resembled that described for live animal and cell culture models of Salmonella spp invasion.
Induction and enhancement of feline infectious peritonitis by canine coronavirus
Authors: McArdle F. , Bennett M. , Gaskell R. M. , Tennant B. , Kelly D. F. , Gaskell C. J.
Published: January 2024

Preexisting antibody to feline infectious peritonitis virus (fipv) causes acceleration and enhancement of disease on subsequent infection of cats with fipv. Other workers have shown that canine coronavirus (ccv) can infect cats subclinically, but have found no evidence of enhancement of, or protection against, subsequent fipv infection. With various isolates of ccv, we determined that 1 strain of ccv can induce transient mild diarrhea in cats and, furthermore, that previous infection with ccv causes acceleration and enhancement of subsequent infection with fipv. In addition, sequential inoculation of cats with another strain of ccv caused lesions indistinguishable from those of fip, without exposure at any time to fipv.
Experimentally induced infection of cats with Borrelia burgdorferi
Authors: Burgess Elizabeth C.
Published: January 2024

To determine whether cats could be infected experimentally with Borrelia burgdorferi, 15 cats were inoculated with approximately 1,000 B burgdorferi. Seven cats were inoculated by the iv route, 2 by the oral route, 2 by the ocular route, and 4 by the oral-ocular route. Six control cats were inoculated with phosphate-buffered saline solution by the iv, oral, and ocular routes. Prior to the start of the study, all 21 cats were seronegative for B burgdorferi on the basis of results of the indirect fluorescent antibody (ifa) test and their blood was B burgdorferi culture negative. All of the iv, orally, and ocularly inoculated cats developed IgG antibodies to B burgdorferi as detected by ifa testing. Of 4 oral-ocularly inoculated cats, 2 developed ifa-detectable antibodies and the remaining 2 cats developed low-titer response (1:128) on postinoculation (pi)day 10 only. All control cats remained seronegative. The organism was detected in blood smears from 2 of the iv inoculated cats on pi days 10 and 24 and from 2 oral-ocularly infected cats, 1 on pi days 17 and 24 and 1 on Pl day 10. Spirochetes were not detected in the blood after pi day 24. The organism was isolated from tissues of only 1 cat (the lung of an ocularly inoculated cat necropsied at 7 months after inoculation). Spirochetes were not isolated from control cats. Neither clinical signs of infection nor gross or histologic abnormalities were found in any of the inoculated or control cats. Results indicate that cats are susceptible to infection with B burgdorferi, but clinically apparent disease may not be common.
Influence of arachidonic acid metabolites and steroids on function of bovine polymorphonuclear neutrophils
Authors: Hoedemaker Martina , Lund Lisa A. , Wagner William C.
Published: January 2024

Polymorphonuclear neutrophils (pmn) from 4 ovariectomized healthy cows were incubated with 0 (control), 10-8, 10-7, and 10-6M arachidonic acid metabolites of the cyclo- and lipoxygenase pathways for 30 minutes, and with steroids for 2 hours. Immediately after incubation, pmn were subjected to the following function assays: chemotaxis against zymosan-activated serum, chemotaxis against arachidonic acid metabolite or steroid at the doses given (only control pmn were tested), random migration, ingestion of 125I-iododeoxyuridine-labeled Staphylococcus aureus (125I-IdUR-S aureus), iodination of proteins, cytochrome C reduction, antibody-independent and -dependent cell-mediated cytotoxicity (aicc and adcc). Prostaglandin F2α was chemoattractant and stimulated ingestion of 125I-IdUR-S aureus. Prostaglandin E2 stimulated cytochrome C reduction, whereas prostacyclin inhibited iodination of proteins. Thromboxane B2 stimulated adcc. Leukotriene B4 was chemoattractant for bovine pmn and stimulated random migration and aicc. 5-Hydroxyeicosatetraenoic acid was also chemoattractant, but inhibited ingestion of 125I-IdUR-S aureus. 15-Hydroxyeicosatetraenoic acid was chemoattractant and decreased adcc. Lipoxin A4 stimulated random migration, whereas lipoxin B4 inhibited chemotaxis against zymosan-activated serum, but was chemoattractant and stimulated cytochrome C reduction. 12-Hydroxyhepadecatrienoic acid and 12-hydroxyeicosatetraenoic acid did not influence any of the pmn functions tested. Of the steroids tested, cortisol increased adcc, and progesterone stimulated cytochrome C reduction, but decreased adcc. 17β-Estradiol and estrone were chemoattractant and stimulated cytochrome C reduction. In addition, estrone also stimulated random migration. Those results suggest that eicosanoids and steroids directly influence function of bovine pmn in vitro in a stimulatory or inhibitory manner, or both, and may act as modulators of bovine pmn function in vivo.
Effects of general anesthesia on myoelectric activity of the intestine in horses
Authors: Lester G. D. , Bolton J. R. , Cullen L. K. , Thurgate S. M.
Published: January 2024

Myoelectric activity was monitored from the terminal ileum, cecum, and colonic pelvic flexure by use of Ag-pAgCl bipolar electrodes in 4 adult horses before, during, and after general anesthesia. Horses were anesthetized by way of 3 commonly used regimens, including xylazine (1.1 mg/kg of body weight) and ketamine hydrochloride (2.2 mg/kg); thiopental sodium (7.7 mg/kg), followed by halothane vaporized in oxygen; and thiopental sodium (2.5 g) in guaifenesin (100 mg/ml) solution given to effect, followed by halothane in oxygen. All 3 anesthetic regimens decreased intestinal spike-burst activity in the areas monitored. The slowest return to preanesthetic myoelectric activity was observed after xylazine and ketamine administration. After both of the barbiturate/halothane anesthetic regimens, there was a rebound increase in spike-burst frequency, without alteration in the proportion of propagative myoelectric events. All 3 anesthetic regimens appeared to reset the timing of the small and large intestinal migrating myoelectric complexes. By 9 hours after recovery from anesthesia, the effects of anesthesia, irrespective of regimen, had disappeared. Although anesthesia significantly (P < 0.05) altered intestinal myoelectric activity, no particular anesthetic regimen had a prolonged effect. Results of our study indicate that the particular chosen regimen of general anesthesia is unimportant in development of motility disturbances in horses after anesthesia.
Treatment of reperfusion injury in dogs with experimentally induced gastric dilatation-volvulus
Authors: Lantz Gary C. , Badylak Stephen F. , Hiles Michael C. , Arkin Terri E.
Published: January 2024

In dogs, gastric dilatation-volvulus (gdv) is characterized by cardiogenic shock, with resulting hypoperfusion. Treatment goals include reperfusion of transiently ischemic tissues, which indicates that reperfusion injury may be a factor in the physiopathogenesis of gdv. Recently, we obtained data that indicate that reperfusion injury may be involved in experimentally induced gdv. Using this gdv model, we evaluated mortality in 24 dogs of 4 equal groups, treated with deferoxamine (an iron chelator), dimethylsulfoxide (a free radical scavenger), a combination of the 2 drugs, or isotonic saline solution. All 6 dogs that were given deferoxamine survived; however, 3 dogs of the dimethylsulfoxide-treated group, 2 dogs of the combination-treated group, and 4 dogs of the saline-treated group died. Results of the study indicate that mortality associated with experimentally induced gdv is reduced by appropriate and timely pharmacologic intervention to prevent or attenuate reperfusion injury, and that deferoxamine may be more effective than dimethylsulfoxide.
Comparison of standard and radionuclide methods for measurement of glomerular filtration rate and effective renal blood flow in female horses
Authors: Matthews Hilary K. , Andrews Frank M. , Daniel Gregory B. , Jacobs William R. , Held Jean-Pierre
Published: January 2024

Comparison of standard and radionuclide methods for measuring glomerular filtration rate (gfr) and effective renal blood flow (erbf) was performed in 8 healthy female horses. Inulin and p-aminohippurate solutions were administered iv as a bolus, followed by sustained administration. Urine and plasma inulin and p-aminohippurate concentrations and urine volume were measured. Glomerular filtration rate and erbf were calculated on the basis of these measurements. Glomerular filtration rate and erbf were measured on the basis of plasma clearance of the radiopharmaceuticals, 99mTc-labeled diethylene-triaminepentaacetic acid (99mTc-dtpa) and [131I]-o-iodo-hippuric acid (131I-oih), respectively. Mean ± sem gfr, using inulin, was 1.83 ± 0.21 ml/min/kg of body weight. Mean gfr, using 99mTc-dtpa was 1.79 ± 0.18 ml/min/kg. Mean erbf, using p-aminohippurate, was 15.13 ± 1.28 ml/min/kg. Mean erbf, using 131I-oih, was 18.42 ± 1.57 ml/min/kg Analysis of variance indicated no significant difference between mean values for gfr and erbf. Radionuclide measurement of gfr and erbf compared well with standard methods and is an alternative technique to the cumbersome standard methods for determination of gfr and erbf in horses.
Pharmacokinetics and local tolerance of a long-acting oxytetracycline formulation in camels
Authors: Oukessou Mohamed , Uccelli-Thomas Valerie , Toutain Pierre-Louis
Published: January 2024

Disposition and local tolerance of a new oxytetracycline (otc) long-acting formulation were evaluated in camels by measuring the dynamics of creatine kinase. Six camels (Camelus dromedarius) were administered otc by iv and im routes according to a 2-period cross-over, study design. Serum otc concentration was measured, using a microbiological assay procedure. After iv administration (5 mg/ kg of body weight), mean residence time was 7.7 ± 2.8 hours, steady-state volume distribution was 706.1 ± 168.6 ml·kg-1 and serum clearance was 75.3 ± 23.2 ml·kg-1·h-1. After im administration of the long-acting otc formulation (10 mg/kg), maximal otc concentration (3.49 ± 0.44 μg·ml-1) was observed after 7.3 ± 3.5 hours; the mean systemic availability was near 100%, and serum concentration > 0.5 μg>ml-1 was maintained for about 72 hours. After im administration, mean control serum activity of creatine kinase was multiplied by a factor of 3.36 ± 1.55; at 72 hours after otc administration, the serum creatine kinase activity returned to control values. It was concluded that otc is an antibiotic of potential interest in camels and that a dosage regimen of 10 mg>kg-1 deserves attention when using a long-acting formulation that has good local tolerance and near total systemic availability.
Maintenance energy requirement of llamas
Authors: Carmean Blair R. , Johnson Kristen A. , Johnson Donald E. , Johnson LaRue W.
Published: January 2024

Five castrated male llamas (mean body weight, 94 kg) were studied in an energy balance trial to determine maintenance energy requirement of llamas. Llamas were fed a 50% oat hay-50% pelleted concentrate diet (2.43 Mcal of metabolizable energy/kg of diet dry matter) at approximately 1.6% of body weight (bw). An 8-day total collection digestion trial was used to determine fecal and urine energy losses. Heat production and methane emissions were determined via indirect respiration calorimetry-measurements on each llama fed at the same level of intake as during the digestion trial and subsequently on days 3 and 4 of a period of nonfeeding. Fecal, urine, and methane energy losses of the llamas fed near-maintenance intake were 32.5, 3.5, and 7.1% of gross energy intake, respectively. The postabsorptive metabolic rate, commonly called nonfed (fasting) heat production, was 59.3 kcal/bw0.75. Using a linear relation between postabsorptive and maintenance energy requirement and efficiency of energy use below maintenance of 0.702, metabolizable energy requirement at maintenance was determined to be 84.5 kcal/bw0.75.
Effect of the somatostatin analogue octreotide on gastric fluid pH in ponies
Authors: Sojka J. E. , Weiss J. S. , Samuels M. L. , You Guey-Mei
Published: January 2024

The effect of the somatostatin analogue, octreotide, on gastric fluid pH was investigated in 4 ponies. Gastric fluid pH was determined after sc administration of octreotide or physiologic saline solution (control). A baseline sample of fluid was obtained, the agent was given, and 8 additional samples were collected hourly. Administration of octreotide at all dosages tested (0.1, 0.5, 1.0, and 5.0 μg/kg of body weight) increased gastric pH to > 5.0. Baseline values were consistently < 2.7. Administration of octreotide at these same dosages induced gastric pH values > 4.0 for 2.4 ± 1.2, 4.8 ± 0.8, 5.7 ± 1.3, and 5.4 ± 2.6 (mean ± sd) continuous hours, respectively. Treatment at all dosages increased the pH of gastric fluid, compared with control values. The duration of the increase in pH was significantly (P < 0.05) different than that of the control treatment, even for the lowest dosage, 0.1 μg/kg.