bluuebunny/crossref_metadata_2025 huggingface dataset:
Some effects of limited exercise on purpose-bred Beagles
Authors: Campbell S. A. , Hughes H. C. , Griffin H. E. , Landi M. S. , Mallon F. M.
Published: February 2025

Amendments to the Animal Welfare Act (PL 99-198) require that an exercise program for dogs be established by the attending veterinarian. A 6-week study was conducted to determine the effects of a moderate exercise program in purpose-bred Beagles. Sixteen male Beagles (4/group) were maintained as follows: (1) standard cage without exercise; (2) standard cage with individual exercise periods (35 minutes, 3 times/week); (3) large cage without exercise; and (4) standard cage with group-release exercise periods. Blood samples were collected for cbc, serum biochemical analysis including determination of serum cortisol concentration, and immune function (lymphocyte transformation assay). Group-released dogs interacted with each other during most of the exercise time. Fighting in these dogs occurred only during the third week. Dogs had little inclination to exercise when released alone into the exercise area. Regardless of the size of the cage, dogs did not exercise unless human beings were present in the room. There were no significant differences in laboratory findings among dogs in the 4 groups. This moderate exercise program had no demonstrable effects. Similarly, continuous cage housing, without a formal exercise program, could not be determined to be detrimental to the physiologic or health status of dogs.
Plasma- and iron-regulated expression of high molecular weight outer membrane proteins by Pasteurella multocida
Authors: Snipes Kurt P. , Hansen Lori M. , Hirsh Dwight C.
Published: February 2025

A strain of Pasteurella multocida of avian origin expressed high molecular weight outer membrane proteins when grown in turkey plasma or in brain-heart infusion broth containing the iron chelator dipyridyl. The proteins were not detected when this strain was grown in brain-heart infusion broth or in brain-heart infusion broth containing dipyridyl and excess iron.
Comparative healing of mesenteric and antimesenteric incisions in the bovine jejunum
Authors: Levine Susan A. , Smith Donald F. , Wilson James W. , Gillette Deborah M. , Kolb David S.
Published: February 2025

Paired incisions (n = 6 pairs) were made in the jejunum of each of 8 Holstein cows. Pairs consisted of 2-cm transverse incisions, 35 cm apart, at the antimesenteric region and at the mesenteric region. Bursting-wall tension was used to test mechanical strength, and cellular and vascular events of healing were evaluated using histologic examination and microangiography. Healing was evaluated at postoperative hour (poh) 48 in 4 of the cows (group 1) and at poh 96 in the remaining 4 (group 2).

Evidence of leakage of intestinal contents was not found in any of the cows. At poh 48 and 96, bursting-wall tension was significantly (P < 0.001) greater in the intestinal segments with antimesenteric incisions than in those segments with mesenteric incisions. Disruption of normal vasculature was seen at mesenteric and antimesenteric sites; ingrowth of vessels, reformation of vascular plexuses, and development of collateral circulation were observed at poh 96. Granulation tissue was observed at poh 96 at the antimesenteric and mesenteric sites, and early stages of mucosal reepithelialization were seen in several sections at poh 48. Better apposition of tissue layers was seen in antimesenteric incisions, but mucosal eversion was evident in several mesenteric incisions. Some sections examined from cows at poh 96 had complete bridging of mucosa, submucosa, and muscularis layers at the antimesenteric location. Inflammatory cells were observed along the incision and at the mucosal and serosal surfaces in many of the sections. Deposition of new collagen was not appreciable in any section at poh 48 or 96.
Use of febantel or ivermectin for treatment of calves with experimentally induced Bunostomum phlebotomum infection
Authors: Yazwinski T. A.
Published: February 2025

In the first of 2 separate trials, the efficacy of febantel, given at a dosage of 5 mg/kg of body weight, was assessed in calves with 60-day experimentally induced Bunostomum phlebotomum infection. Ten calves were given febantel paste, and 10 were given the vehicle only. All 20 calves were necropsied 7 days after cessation of treatment. Compared with untreated calves, febantel-treated calves harbored 99.4% fewer nematodes.

In the second trial, the efficacy of ivermectin, given as a paste formulation at a dosage of 0.2 mg/kg, was assessed in calves with experimentally induced B phlebotomum infection. Ivermectin was given at 18 (n = 6) and 60 (n = 6) days after infection. At each treatment date, 3 additional calves were given vehicle only. At 67 days after infection, all calves were euthanatized. Efficacies of ivermectin against 18- and 60-day infections were 100 and 99.8%, respectively.

Both anthelmintic preparations were easily administered, and adverse reactions were not observed.
Effect of flunixin meglumine on Escherichia coli heat-stable enterotoxin-induced diarrhea in calves
Authors: Roussel A. J. , Sriranganathan N. , Brown Scott Anthony , Sweatt Donna
Published: February 2025

In a study to evaluate the effect of flunixin meglumine on secretory diarrhea, 11 calves were assigned to 3 groups: group 1 (n = 3) served as controls, group-2 calves (n = 4) were given 2.2 mg of flunixin meglumine/kg, im at 7 am and 3 pm, and group-3 calves (n = 4) were given 2.2 mg of flunixin meglumine/kg, im at 7 am, 11 am, and 3 pm. All calves were given approximately 200 μg of heat-stable Escherichia coli enterotoxin (STa) orally at 8 am. Mean cumulative fecal output for groups 1, 2, and 3 was 1,331.0 ± 317.2 g, 1,544.3 ± 154.4 g, and 785.5 ± 276.5 g, respectively. There was a significant (P < 0.05) reduction in mean fecal output in group-3 calves, compared with that in groups 1 and 2. Calves in group 2 tended to have a delay, but not a reduction, in their fecal output. At 12 hours, hemoconcentration was significantly (P < 0.05) greater in group-1 calves than in group-2 or group-3 calves.
Case-control study of risk factors associated with nosocomial Salmonella krefeld infection in dogs
Authors: Uhaa Iyorlumun J. , Hird David W. , Hirsh Dwight C. , Jang Spencer S.
Published: February 2025

In a case-control study of risk factors associated with an episode of nosocomial Salmonella krefeld infection in dogs at the veterinary medical teaching hospital, data on 20 case dogs and 75 control dogs were obtained by review of hospital records.

Univariate and multivariate statistical analyses were carried out for possible risk factors for infection to obtain odds of Salmonella krefeld isolation, given exposure to each risk factor of interest. Compared with control dogs, case dogs were 11.9 times more likely to have been fed rice, 7 times more likely to have had radiography done, 10.2 times more likely to have been a resident in ward 2, 5.6 times more likely to have been given antimicrobial agents orally, 11.3 times more likely to have been given antimicrobial agents parenterally, and 37.9 times more likely to have been given antimicrobial agents orally and parenterally (P < 0.05).
Kinematic analysis of the instant centers of rotation of the equine metacarpophalangeal joint
Authors: Colahan Patrick , Piotrowski George , Poulos Paul
Published: February 2025

A kinematic analysis of the instant centers of rotation analysis was performed on 21 metacarpophalangeal joints from 11 horses. Manual and computerized methods were used to locate the instant center of rotation on photocopies of transparent composite tracings of a series of radiographs of each joint. The instant centers of rotation of the proximal phalanx about the distal portion of the third metacarpal bone were located consistently on or near the eminence for attachment of the collateral ligaments. The instant centers of rotation of the sesamoids about the distal portion of the third metacarpal bone were consistently located near the dorsal articular margin of the distal portion of the third metacarpal bone. Rotation of the joint as it extended caused minor variation in radiographic projection. This variation in radiographic projection limited the precision of the analysis of the instant center of rotation and prevented the identification of a single instant center of rotation or an instant center of rotation pathway for the articulation of the proximal phalanx or the proximal sesamoids with the distal portion of the third metacarpal bone.

The articular surface velocity vectors determined from the instant centers of rotation indicated that the joint surfaces slide on each other. The motion of the joint caused compression at the dorsal articular margins at maximal extension and thereby limited further extension. At this degree of extension, the proximal sesamoids articulated only with the proximal sesamoid-metacarpal articular surface of the distal portion of the third metacarpal bone.
Comparison of histamine release induced by morphine and oxymorphone administration in dogs
Authors: Robinson Elaine P. , Faggella Alicia M. , Henry David P. , Russell Weihua L.
Published: February 2025

Cardiovascular effects (vasodilatation, hypotension) of morphine administration have been attributed to central actions and peripheral histamine release. In the study reported here, we compared plasma histamine (Hm) concentrations after morphine sulfate and oxymorphone HCl administration in conscious dogs. Five healthy adult dogs (mean body weight, 10.1 kg) were randomly administered morphine (2 mg/kg of body weight, iv) or oxymorphone (0.2 mg/kg, iv) by a 5-second bolus injection at weekly intervals. Venous blood samples (5 ml) were collected from jugular veins before and at 1, 2, 5, 15, 30, and 60 minutes after drug administration. Behavioral changes were recorded. Plasma was analyzed by a radioenzymatic technique, using purified histamine N-methyltransferase as an enzyme catalyst (sensitivity of assay, 40 pg Hm/ml). Mean base-line Hm value for all dogs was 0.55 ng/ml. The mean Hm value was significantly higher (P < 0.05) than the base-line value at 1, 2, 5, 15, and 60 minutes after morphine administration (531.4, 251.0, 113.0, 31.5, and 1.0 ng of Hm/ml, respectively), but there were no significant increases in histamine values from base-line values at any time after oxymorphone administration. All dogs given morphine and 1 dog given oxymorphone showed excitatory behavior; 2 dogs given morphine and 3 dogs given oxymorphone salivated profusely.
Cardiovascular effects of acupuncture stimulation at point Governing Vessel 26 in halothane-anesthetized ponies
Authors: Dill Stephen G. , Gleed Robin , Matthews Nora S. , Erb Hollis N. , Miller Timothy K.
Published: February 2025

The acupuncture point Governing Vessel 26 (GV-26) is used commonly in the Orient to treat shock in human beings and other species. The cardiovascular effects of stimulation of GV-26 were studied in healthy ponies during 2 episodes of halothane anesthesia. During one anesthetic episode, electrical stimulation (electrostimulation) of GV-26 was performed, and during the other anesthetic episode, heat stimulation (moxibustion) of GV-26 was performed. The order of the stimulations was random. A nonacupuncture point was selected for comparable control stimulation during each experiment. Control and acupuncture stimulations were of equal intensity. There were no significant changes in cardiac output, systemic arterial pressure, or heart rate associated with either electrical or heat acupuncture stimulation.
Enhancement of infectious bovine keratoconjunctivitis by modified-live infectious bovine rhinotracheitis virus vaccine
Authors: George Lisle W. , Ardans Alex , Mihalyi Judy , Guerra Mario Reina
Published: February 2025

The effects of a modified-live infectious bovine rhinotracheitis virus vaccine (administered ocularly or intranasally) on experimentally induced infectious bovine keratoconjunctivitis were evaluated. The modified-live infectious bovine rhinotracheitis virus vaccine was administered to 13 male Holstein calves (intranasally in 4 and ocularly in 9; day 0). Five calves were not vaccinated and served as controls. Calves were examined daily and, starting on day 4, Moraxella bovis was administered ocularly to all 18 calves once daily for 4 days. The eyes of all calves were assigned a clinical score, and the ocular secretions were evaluated for presence of infectious bovine rhinotracheitis virus and M bovis daily until day 19. The severity of the ocular lesions was estimated by scoring the lesions clinically and by determining the protein concentration, myeloperoxidase activity, and wbc count in the tears.

By day 5, conjunctivitis, chemosis, and epiphora were observed in all of the calves vaccinated ocularly. The calves vaccinated intranasally developed conjunctival plaques, but did not develop chemosis or photophobia. All of the calves developed keratitis after inoculation with M bovis. The median lesion scores were greater in both groups of vaccinated calves than in the controls. Corneal perforations developed exclusively in the vaccinated calves. The frequency of M bovis isolation from ocular secretions was significantly (P < 0.05) greater in the vaccinated calves than in the controls. The tears from the intranasally vaccinated calves contained the highest myeloperoxidase activity and wbc count. The mean protein concentration in the tears of vaccinated calves was not significantly different from that in tears of controls. Infectious bovine rhinotracheitis virus was recovered from ocular secretions of vaccinated calves daily for 11 days and then intermittently thereafter until day 19.
Identification and control of paratuberculosis in a large goat herd
Authors: Gezon Horace M. , Bither Henry D. , Gibbs Harold C. , Acker Elizabeth J. , Hanson Linda A. , Thompson Jeffrey K. , Jorgenson Richard D.
Published: February 2025

Mycobacterium paratuberculosis infection was detected in 2 goats in 1974 and in 5 goats in 1975; 5 of which were from a single herd. The magnitude of the subsequent epizootic in the goat herd was not recognized until 1977, when results of bacteriologic culture of fecal and tissue specimens, antibody determinations (agar-gel immunodiffusion test), and histopathologic studies became available. By 1984, paratuberculosis had been diagnosed in 124 goats. Nearly all the goats were being used in antiserum production and had been given Freund complete adjuvant and human antigens. From 1974 to 1986, herd size varied from 100 to 300. The yearly incidence of paratuberculosis decreased from 13.2% (27 of 204 goats) in 1977 to 0% in 108 goats in 1985. The prevalence was higher in does. In goats that arrived on the farm in 1975 and before, 49 of 121 (40.5%) does developed paratuberculosis vs 41 of 120 (34.2%) wethers. In goats arriving on the farm in 1976 and after, 25 of 274 (8.5%) does and 9 of 216 (4.1%) wethers developed paratuberculosis. The average incubation period was approximately 4 years from arrival on the farm in every year except 1978, regardless of whether the goat was born on the farm or was purchased elsewhere.

Pathologic studies revealed gross and microscopic lesions predominantly in the lower portion of the ileum and associated lymph nodes; however, in goats with advanced disease, lesions were detected in the entire intestinal tract, liver, spleen, and lungs. Amyloidosis was detected in the spleen, liver, kidneys, and/or adrenal glands of 67 of 118 (56.8%) necropsied goats with paratuberculosis and 149 of 387 (38.5%) goats without bacteriologic and/or histologic evidence of paratuberculosis.

Nonrandomized therapeutic trials were conducted in 19 goats with fecal cultures considered positive for M paratuberculosis: 4 were given isoniazid; 4 were given isoniazid plus rifampin; 4 were given isoniazid plus ethambutol; and 7 were given isoniazid, rifampin, and ethambutol. All drugs were given orally each day for 3 to 16 months, but without success.

Major changes were made in herd management to control the epizootic and to eradicate the disease. Using agar-gel immunodiffusion testing quarterly, bacteriologic culture of fecal specimens semiannually, and weighing all goats monthly, earlier diagnosis of paratuberculosis was achieved. Isolation or euthanasia of all goats with confirmed or suspected paratuberculosis was carried out promptly. All young and newly purchased goats were quarantined. Strict sanitation rules were followed. The herd has remained free of paratuberculosis since 1984.
Visual-evoked potentials in cats, using a light-emitting diode stimulator
Authors: Sims Michael H. , Laratta Louis J.
Published: February 2025

Visual-evoked potentials (vep) were studied in 8 healthy adult cats anesthetized with xylazine HCl and ketamine HCl. Monocular visual stimulation was accomplished by a 3 × 5 matrix of light-emitting diodes. Subcutaneous needle electrodes placed in the scalp at various locations and a contact lens electrode on the cornea were used to record cortical and electroretinographic activities, respectively. Multiple electrode pairings and unilateral optic nerve transsection were used to distinguish between retinal and postretinal potentials recorded from scalp electrodes. The vep was a robust polyphasic cortical potential, with peak latencies between 0 and 110 ms. Using the light-emitting diode method of stimulation, a vep was recorded which was not contaminated by volume-conducted retinal activity.
Comparison of cardiopulmonary effects of isoflurane and halothane after atropine-guaifenesin-thiamylal anesthesia for rumenotomy in steers
Authors: Greene S. A. , Tyner C. L. , Morris D. L. , Hartsfield S. M.
Published: February 2025

Cardiopulmonary effects were assessed in 12 yearling steers anesthetized with guaifenesin and thiamylal sodium, intubated, and allowed to breathe isoflurane or halothane in oxygen spontaneously. Light surgical anesthesia, determined using eye position as a clinical indication of anesthetic depth, was maintained during surgical placement of a rumen cannula. Heart rate and respiratory rate were measured while the steers were standing quietly (baseline). Atropine (0.06 mg/kg of body weight, im) was given after baseline measurements were taken. Heart rate, respiratory rate, arterial blood pressures, pHa, Paco2, Pao2, arterial [HCO3−], esophageal temperature, and end-tidal anesthetic concentration were measured every 15 minutes for 90 minutes after induction of anesthesia.

Mean heart rate increased significantly (P < 0.05) above baseline in the isoflurane group at 15 and 30 minutes. Mean respiratory rate increased significantly (P < 0.05) above baseline in the halothane group at 45 minutes. At 45 minutes, mean respiratory rate was lower (P < 0.05) in the isoflurane group, compared with that in the halothane group. Mean values for arterial blood pressures and arterial gases were similar for both agents at comparable times. Mean end-tidal isoflurane concentrations were less than mean end-tidal halothane concentrations at each comparable time during maintenance of similar anesthetic depth. Maintenance of anesthesia with isoflurane resulted in higher heart rates and lower respiratory rates, compared with maintenance of anesthesia with halothane in these steers.
Influence of furosemide treatment on fluid and electrolyte balance in horses
Authors: Freestone John F. , Carlson Gary P. , Harrold Doris R. , Church Gabie
Published: February 2025

Alterations in electrolyte and acid-base balance were studied in 6 horses for 8 hours after furosemide administration (1 mg/kg of body weight, im), and the results were compared with those for 5 healthy untreated horses (controls) kept under identical environmental conditions. In the treated group, decreases in plasma potassium, chloride, and calcium concentrations and increases in total plasma protein content persisted for the 8-hour observation period, whereas there was no change in plasma sodium concentration, osmolality, or packed cell volume. Plasma bicarbonate concentration and Pco2 remained high throughout the study, during which time venous blood pH was modestly increased only at the 6-hour sampling time. Furosemide treatment resulted in decreases in urine pH, specific gravity, osmolality, and potassium and calcium concentrations and increases in urine volume and total urine sodium, chloride, and calcium excretion. Body weight decreased 19.2 ± 5.2 kg (mean ± sd) in treated horses (4 ± 1% of body weight), compared with a weight loss of 8 ± 2.1 kg in untreated horses (1.5 ± 0.4% of body weight) during the 8-hour experimental period. The increased fluid losses induced by the diuretic did not cause any obvious clinical signs in the horses. Pulse pressure, skin turgor, capillary refill time, and jugular distensibility remained unchanged throughout the experimental period.
In vitro susceptibility of canine tumor stem cells to doxorubicin
Authors: Macy Dennis W. , Ensley Beverly A. , Gillette Edward L.
Published: February 2025

Thirty-four canine tumor specimens (13 sarcomas and 21 carcinomas) were grown in soft agar gel. Susceptibility after continuous exposure to doxorubicin at concentrations of 1, 5, and 10 μg/ml was compared with that of control cultures. Plating efficiency averaged 0.096%. Doxorubicin at a concentration of 1 μg/ml was found to result in > 70% inhibition of colony formation in 3 of 13 sarcomas and 1 of 21 carcinomas tested, and > 50%, but < 70%, inhibition in 3 carcinomas and 1 sarcoma. Twenty-six tumors had < 50% reduction in colony formation and were considered resistant. Minor differences in responses to drug in primary and metastatic locations were observed and attributed to tumor heterogeneity and test variability.
Experimentally induced bluetongue virus infection in white-tailed deer: Ultrastructural findings
Authors: Howerth E. W. , Tyler D. E.
Published: February 2025

White-tailed deer (Odocoileus virginianus) were inoculated with bluetongue virus serotype 17 and sequentially euthanatized during infection. Ultrastructural changes in the microvasculature of tongue, buccal mucosa, heart, and pulmonary artery, platelets, and bone marrow were evaluated.

Bluetongue virus was found in endothelial cells of the microvasculature by postinoculation day 4. Viral replication was associated with the development of viral matrices, viral-associated macrotubules, and aggregates of mature viral particles in the cytoplasm of infected cells. Viral infection of pericytes and vascular smooth muscle cells developed subsequent to endothelial cell infection.

Viral infection was associated with striking changes in the endothelial lining of the microvasculature by post-inoculation day 4. Endothelial cell degeneration and necrosis, which resulted in denudation of the endothelial lining, and endothelial cell hypertrophy frequently were observed. Thrombosis, hemorrhage, and vessel rupture developed subsequent to endothelial damage. Bluetongue virus neither infected nor directly damaged platelets or bone marrow cells.

It was concluded that viral-induced endothelial damage is the primary triggering mechanism for disseminated intravascular coagulation in bluetongue virus infection. Vascular damage coupled with the development of disseminated intravascular coagulation is responsible for the hemorrhagic diathesis, which is characteristic of bluetongue virus infection in white-tailed deer.
Oxfendazole: Activity of a two-dose treatment regimen on natural infections of internal parasites of equids, with emphasis on migrating large strongyles in controlled tests in 1986 and 1987
Authors: Lyons E. T. , Tolliver S. C. , Drudge J. H. , Swerczek T. W.
Published: February 2025

Oxfendazole paste formulation was administered intraorally at a dosage of 10 mg/kg of body weight, twice (48 hours between treatments) in 5 controlled tests (experiments A, B, C, D, and E) to 18 equids (14 horses and 4 ponies) that were 5 to 24 months old in 1986 and 1987. Activity was evaluated against naturally acquired infections of various internal parasites, with emphasis on migratory stages of Strongylus vulgaris and S edentatus. The number of treated and nontreated equids in each experiment (horses in experiments A to D and ponies in experiment E) was: A, 1 and 1; B, 3 and 3; C, 3 and 1; D, 1 and 1; and E, 2 and 2, respectively. At 28 to 39 days after the first dose of the 2-dose treatment regimen, the equids were euthanatized and examined for several species of internal parasites.

On the basis of the number of specimens at necropsy, excellent activity was found against migrating (retroperitoneal) S edentatus. In the aggregate for the 5 experiments, 41 live specimens of S edentatus were recovered from 10 treated equids, compared with 810 live specimens from the 8 nontreated equids, reflecting a difference of 95%. Several dead S edentatus were found in 8 treated equids. Three to 82 semihard nodules, which we believed were S edentatus-related lesions, were found in treated horses; only soft, seroedematous lesions, typical of S edentatus infection, were found in nontreated equids.

In the cranial mesenteric arteries, activity for migrating S vulgaris was good overall. In the aggregate for the 5 experiments, 71 live S vulgaris organisms were recovered from the cranial mesenteric arteries of the 10 treated equids, compared with 1,136 from the 8 non-treated equids, reflecting a difference of 94%. A few dead organisms were found in 3 treated equids. Arterial lesions were generally less severe in treated than in non-treated equids, and resolution of the lesions was evident in the treated equids.

Excellent activity was recorded against intestinal stages of Parascaris equorum, S vulgaris, and Oxyuris equi. Oxfendazole appeared to have some effect on eyeworms (Thelazia lacrymalis), although generally low numbers were found in nontreated equids.

Toxicosis was not evident in any of the treated equids.
Correlation between B-cell mitogenicity and immunosuppessor effects of a protein released by porcine monocytes infected with African swine fever virus
Authors: Arala-Chaves Mário Passalaqua , dos Santos Ribeiro Adilia , Vilanova Manuel , Porto Maria Teresa , Santarem Manuel G. , Lima Margarida
Published: February 2025

Virus-free supernatants of cultured swine monocytes infected by African swine fever virus (asfv) suppressed in vitro proliferation of porcine and human blood mononuclear cells in response to phytohemagglutinin and the in vivo primary immune response of C57BL/6 mice against sheep rbc. The supernatants were fractionated by discontinuous ion-exchange chromatography and subfractionated by double-step preparative isoelectric focusing. The pool of the most purified active subfractions (F5′EP-asfv) is made up of heat-unstable material, can be stained by silver nitrate, and has an isoelectric point of 3.88, a maximal optical density at 280 nm, and a mass of 36,000 daltons. In vivo kinetic studies in nonimmunized C57BL/ 6 mice were performed on days 1, 2, 3, 5, and 7 after injection with 50 μg of F5′EP-asfv protein. Compared with the untreated mice, the treated mice had a noticeable increase in nonspecific immunoglobulin-secreting splenic plaque-forming cells (pfc) with the following isotype profile: IgG2a > IgG2b > IgG3 > IgGl ≃ IgM. Three days after treatment with the active material, specific IgM pfc against sheep rbc increased up to 23-fold. In C57BL/6 mice immunized against sheep rbc 2 days after treatment with F5′EP-asfv, the increase in nonspecific pfc was followed by a suppression of specific pfc response in the respective isotype. When C57BL/6 mice were treated after priming with sheep rbc, however, there was little or no suppression of specific pfc and the increase in nonspecific pfc was considerably lower than that in the other FS′EP-asfv-treated mice. In this case, kinetic curves of specific vs nonspecific pfc of each isotype were mirror images. Mice treated with 200 μg of F5′EP-asfv protein died with hemorrhagic diastasis.
Prognostic index for acute abdominal crisis (colic) in horses
Authors: Orsini J. A. , Elser A. H. , Galligan D. T. , Donawick W. J. , Kronfeld D. S.
Published: February 2025

Selected physical and laboratory findings in 29 horses with acute abdominal crisis were evaluated retrospectively with a logistic regression equation to predict survival or death. Of 17 variables examined, 2 were found to have good predictive correlation. Serum lactate and packed cell volume had a combined predictive value of 94%. Packed cell volume mean values of 43 and 50%, respectively, differentiated survival from death. Serum lactate values of 28.18 mg/dl and 51.28 mg/dl differentiated survival and death.

Analysis of data from a previous study of 36 horses with the logistic regression equation predicted survival rate of 96% accuracy, further substantiating the statistical model.
Effects of milbemycin on adult Toxocara canis in dogs with experimentally induced infection
Authors: Bowman Dwight D. , Parsons James C. , Grieve Robert B. , Hepler Douglas I.
Published: February 2025

To determine the efficacy of a formulation of milbemycins in treating patent infection with Toxocara canis, 8 male and 7 female, 10-week-old, ascarid-free Beagles each were given 125 embryonated eggs of T canis. All dogs developed patent infection within 56 days. On postinfection day 70, the dogs were assigned to 1 of 3 groups of 5 dogs each; members of 1 group were given a placebo, while dogs of the other 2 groups were given either 5.68 or 34.08 mg of the milbemycin formulation, respectively. In both groups of dogs given the drug, the number of eggs passed per gram of feces decreased precipitously. However, a few eggs still were found in the feces of several dogs of each group on the day of necropsy (postinfection day 75). Worms or fragments of worms were passed by the treated dogs from the day of treatment until the day on which necropsy was performed; however, most worms were passed during the first 2 days after treatment. At necropsy, only dogs of the control group were found to harbor adult T canis.
Distribution of Brucella abortus organisms in calves after conjunctival exposure
Authors: Meador V. P. , Warner D. P. , Deyoe B. L.
Published: February 2025

Thirty calves (3 to 4 months old) were exposed conjunctivally to a pathogenic strain of Brucella abortus. Calves were euthanatized and necropsied at postexposure hours 2 and 4, and at postexposure days (ped) 1, 4, 7, 14, 21, 42, and 49. Selected ocular, pharyngeal, and lymphoid tissues were cultured bacteriologically for brucellae to determine organism distribution. Brucella abortus organisms initially localized in the third eyelids, bulbar conjunctivae, and parotid lymph nodes and were detected in these structures until ped 42, 21, and 49 respectively. In calves euthanatized at ped 7, organisms were in other cranial lymph nodes (mandibular and retropharyngeal), and in calves euthanatized at ped 21, organisms were isolated from peripheral lymphoid tissues. Brucellae were not isolated from mesenteric and bronchial lymph nodes and from the spleen until ped 21. The pattern of isolation indicated that conjunctival exposure probably resulted in entrance of brucellae into the host via ocular tissues.
In vitro susceptibility of bacteria to a ticarcillin-clavulanic acid combination
Authors: Sparks Susan E. , Jones Robert L. , Kilgore W. Randal
Published: February 2025

In vitro testing of bacterial susceptibility to a combination of ticarcillin and clavulanic acid was done, using 406 aerobic gram-positive and gram-negative isolates (considered to be pathogens) cultured from equine and small animal specimens.

A microdilution broth technique of susceptibility testing was performed, using trays with wells containing a range of doubling concentrations of dehydrated ticarcillin (range, 0.50 to 128 μg/ml) with fixed concentration of clavulanic acid (4 μg/ml).

The following isolates of equine origin were (90%) susceptible to concentrations of ticarcillin and clavulanic acid combinations of ≤ 16 and 4 μg/ml, respectively: Staphylococcus aureus, S intermedius, Klebsiella pneumoniae, Enterobacter aerogenes, Ent agglomerans, Ent cloacae, Escherichia coli, Actinobacillus sp, Corynebacterium pseudotuberculosis, Rhodococcus equi, Proteus vulgaris, and Bordetella bronchiseptica. Isolates of small animal origin (90%) susceptible to ≤ 16 and 4 μg of ticarcillin-clavulanic/ml included S aureus, S intermedius, Ent aerogenes, Ent agglomerans, Pasteurella multocida, B bronchiseptica, Pr mirabilis, and Serratia sp.
Cellular defense of the avian respiratory system: Effects of Pasteurella multocida on respiratory burst activity of avian respiratory tract phagocytes
Authors: Ochs Duane L. , Toth Thomas E. , Pyle Robert H. , Siegel Paul B.
Published: February 2025

The respiratory tract of healthy chickens contain few free-residing phagocytic cells. Intratracheal inoculation with Pasteurella multocida stimulated a significant (P < 0.05) migration of cells to the lungs and air sacs of White Rock chickens within 2 hours after inoculation. We found the maximal number of avian respiratory tract phagocytes (22.9 ± 14.0 × 106) at 8 hours after inoculation. Flow cytometric analysis of these cells revealed 2 populations on the basis of cell-size and cellular granularity. One of these was similar in size and granularity to those of blood heterophils. Only this population was capable of generating oxidative metabolites in response to phorbol myristate acetate. The ability of the heterophils to produce hydrogen peroxide, measured as the oxidation of in-tracellularly loaded 2′,7′-dichlorofluorescein, decreased with time after inoculation. These results suggest that the migration of heterophils, which are capable of high levels of oxidative metabolism, to the lungs and air sacs may be an important defense mechanism of poultry against bacterial infections of the respiratory tract.
Pathologic, hematologic, and serologic changes in rabbits given T-2 mycotoxin orally and exposed to aerosols of Aspergillus fumigatus conidia
Authors: Niyo K. A. , Richard J. L. , Niyo Y. , Tiffany L. H.
Published: February 2025

The influence of immunosuppression by T-2 mycotoxin on the fungal disease aspergillosis was investigated in rabbits. Four groups of rabbits (groups 1A, 1B, 3A, and 3B) were given 0.5 mg of T-2 toxin/kg of body weight/day, po; in addition, rabbits of groups 3A and 3B were exposed to aerosols of Aspergillus fumigatus conidia from days 7 through 16. Rabbits of groups 2A and 2B were exposed to A fumigatus aerosols, but were not given T-2 toxin, and rabbits of group 0 served as controls. Two rabbits of group 1A, 1 rabbit of group 1B, and 1 rabbit of group 3A died before scheduled necropsy. Rabbits of groups 1A, 2A, and 3A were killed and necropsied on day 17, and the remaining rabbits (groups 0, 1B, 2B, and 3B) were killed and necropsied on day 28. Changes caused by T-2 toxin included leukopenia, marginal anemia, and increased number of and morphologic changes in nucleated erythrocytes by day 21, followed by a regenerative hematologic response. Serum alkaline phosphatase and sorbitol dehydrogenase activities and antibody response to A fumigatus (as measured by an indirect hemagglutination test) were decreased by T-2 toxin ingestion. Rabbits with aspergillosis had leukocytosis, increased pcv, and increased antibody response to A fumigatus. Histologic lesions consisting of centrilobular hepatocellular swelling, portal and periportal fibrosis, and lymphocyte necrosis and/or depletion within secondary lymphoid tissue were observed in most rabbits treated with T-2 toxin. Normal defense mechanisms against A fumigatus infection were compromised by T-2 treatment, as evidenced by the severity and extent of lung lesions, greater number of hyphal elements observed, and greater number of colonies of A fumigatus isolated from rabbits of groups 3A and 3B. There were no significant changes in group-0 rabbits.
Clinical evaluation of transmissible gastroenteritis virus vaccines and vaccination procedures for inducing lactogenic immunity in sows
Authors: Moxley Rodney A. , Olson LeRoy D.
Published: February 2025

Two federally licensed attenuated live transmissible gastroenteritis (TGE) virus vaccines (an IM vaccine and an oral-IM vaccine) and 1 nonlicensed nonattenuated live TGE virus vaccine were evaluated and compared in sows free of TGE virus-neutralizing antibodies. Litters from the sows were challenge exposed at 3 and 5 days of age, and results were combined according to the vaccine administered to the sows. The survivability of pigs suckling sows vaccinated with the nonattenuated vaccine was significantly (P < 0.01) greater than that of pigs suckling sows vaccinated with the IM attenuated vaccine, significantly (P<0.05) greater than that of pigs suckling sows vaccinated with the oral-IM attenuated vaccine, and significantly (P < 0.05) greater than that of pigs suckling sows that had not been vaccinated. The differences, however, between survivability of litters from sows vaccinated with the IM attenuated vaccine or the oral-IM attenuated vaccine and that of litters from the sows not vaccinated were not significant (P> 0.10). The nonattenuated TGE vaccine, although giving a higher level of protection than the attenuated vaccine, was eventually overwhelmed. Dexamethasone did not increase the incidence of diarrhea, and levamisole did not potentiate the lactogenic immunity in sows after given their first dose of the nonattenuated vaccine. Survivability in litters suckling sows that developed diarrhea after given their first dose of the nonattenuated vaccine was not greater than that in litters suckling sows that did not develop diarrhea. The best results were obtained when 3-day-old suckling pigs were challenge exposed with virulent TGE virus.
Effect of vaccination with a pentavalent leptospiral vaccine on Leptospira interrogans serovar hardjo type hardjo-bovis infection of pregnant cattle
Authors: Bolin Carole A. , Thiermann Alejandro B. , Handsaker Annette L. , Foley John W.
Published: February 2025

Effectiveness of a pentavalent leptospiral vaccine to protect cattle from infection and reproductive problems caused by Leptospira interrogans serovar hardjo type hardjo-bovis was evaluated. Seven cows were vaccinated once and 8 cows were vaccinated twice with a USDA-licensed pentavalent leptospiral vaccine. Five cows were maintained as nonvaccinated controls. Cows were bred 1 to 2 months after the last vaccination. During the 4th to 6th month of gestation, all cows were challenge exposed on 4 occasions by conjunctival instillation of 108 serovar hardjo type hardjo-bovis organisms and on 3 occasions by conjunctival instillation of urine from a cow shedding hardjo-bovis. All control cows and 13 of 15 vaccinated cow became infected and shed leptospires in the urine. Leptospires were detected in fewer urine samples collected from vaccinated cows, compared with those collected from control cows. Four stillborn calves and 3 weak calves were born to control and vaccinated cows. Leptospires were detected in the kidneys of 11 apparently healthy calves born to vaccinated and control cows. Agglutinating antibodies were not detected inthe precolostral glutinating tral serum of these calves.
Comparative effects of cholera toxin, Salmonella typhimurium culture lysate, and viable Salmonella typhimurium in isolated colon segments in ponies
Authors: Murray Michael J. , Doran Richard E. , Pfeiffer Carl J. , Tyler David E. , Moore James N. , Sriranganathan Nammalwar
Published: February 2025

Isolated segments of left dorsal colon and a side-to-side colocolostomy (between the left ventral colon and left dorsal colon) were surgically created in 6 adult ponies. Four segments, each separated by an empty segment, were inoculated (20 ml) with 1 of the following 4 solutions : phosphate buffered saline solution (PBSS)/1% polyethylene glycol (PEG); purified cholera toxin in PBSS/1% PEG (5 μg cholera toxin/ml of PBSS/1% PEG); lyophilized Salmonella typhimurium UCD 1755 culture lysate, reconstituted in PBSS/1% PEG; and viable S typhimurium UCD 1755 (108 organisms/ml of PBSS /1% PEG). Twenty hours following inoculation of the treatment solutions into the isolated colon segments, the ponies were reanesthetized. Fluid accumulation in the isolated segments was measured, and tissue samples from isolated segments were taken for examination by light microscopy and electron microscopy, and for measurement of mucosal cyclic adenosine monophosphate levels.

There was fluid accumulation in segments inoculated with cholera toxin in 4 ponies (29.5 ± 12.7 ml), and in segments inoculated with S typhimurium UCD 1755 culture lysate in 3 ponies (14.0 ± 8.7 ml). There was no fluid accumulation in segments inoculated with either the control solution (PBSS /1% PEG) or viable S typhimurium UCD 1755. There was significantly (P < 0.05) less cyclic adenosine monophosphate in segments inoculated with cholera toxin, Salmonella lysate, and viable Salmonella, compared with control segments. Histologically, there were minimal changes in control segments, consisting of mild to moderate submucosal edema and capillary congestion. Changes in the other segments were more pronounced and included neutrophilic infiltration and exocytosis, with the changes increasing in severity in the segments inoculated with cholera toxin, S typhimurium culture lysate UCD 1755, and viable S typhimurium UCD 1755, respectively. Ultrastructurally, mucosa from control segments was normal. Mucosa from segments inoculated with cholera toxin had swollen endoplasmic reticula and basolateral separation of surface epithelial cells. Mucosa from segments inoculated with S typhimurium UCD 1755 culswollen smooth and rough endoplasmic reticula, separature lysate and viable S typhimurium UCD 1755 had tion of epithelial cells, degeneration of microvilli, and goblet cell degeneration.
Evaluation of the specificity of Pasteurella multocida somatic antigen-typing antisera prepared in chickens, using ribosome-lipopolysaccharide complexes as inocula
Authors: Rimler R. B. , Angus R. D. , Phillips M.
Published: February 2025

Purified lipopolysaccharides (LPS) from 16 serotypes of Pasteurella multocida were complexed with Aspergillus fumigatus ribosomes. The complexes were used as inocula to prepare antisera, in chickens, for somatic antigen typing by the gel diffusion precipitin test (GDPT). Antisera made against 15 of 16 LPS reacted with their respective specific heat-stable antigens in the GDPT and homologous LPS in the passive hemagglutination test. Antisera could not be made against serotype 15 LPS. Correlation was not observed between intensity of the precipitin reaction in the GDPT and titer to homologous LPS in the passive hemagglutination test. Most antisera cross-reacted with other heat-stable antigens of other serotypes in the GDPT. Many of these cross-reactions were eliminated by dilution. Crossreactions that occurred in the GDPT with antisera made against LPS of serotypes 2,5,7, and 8 could not be eliminated by dilution.
Effects of distention and neostigmine on jejunal vascular resistance, oxygen uptake, and intraluminal pressure changes in ponies
Authors: Parks H. , Stick J. A. , Arden W. A. , Chou C. C. , Hengemuhle S. M.
Published: February 2025

The influence of distention (high baseline intraluminal pressure) and neostigmine methylsulfate on intestinal vascular resistance, oxygen uptake, and intraluminal pressure changes (rhythmic contractions) was studied in terminal jejunal segments, which were perfused at a constant rate, in 16 anesthetized ponies. When baseline intraluminal pressure was increased to 10 mm of Hg, the intestinal vascular resistance and amplitude of rhythmic contractions were increased. Neostigmine induced cyclic increases in amplitude of rhythmic contractions whether intraluminal pressure was 0 or 10 mm of Hg. Neostigmine also increased intestinal oxygen uptake at intraluminal pressures of 0 mm of Hg, but not at 10 mm of Hg, and vascular resistance was not altered at either intraluminal pressure. The results indicate that intestinal hemodynamics are adversely affected by distention. Further, neostigmine did not adversely affect intestinal hemodynamics while increasing rhythmic contractions, suggesting that neostigmine may be useful in the treatment of ileus in equids.
Pulsed-wave Doppler evaluation of intracardiac blood flow in 30 clinically normal Standardbred horses
Authors: Reef Virginia B. , Lalezari Khosrow , De Boo Job , van der Belt Anton Jan , Spencer Pamela A. , Dik Kees J.
Published: February 2025

Pulsed-wave Doppler echocardiography was performed on 30 clinically normal 1-to 6-year-old racing Standardbreds. There were 13 females, 13 geldings, and 4 stallions. Cardiac disease was not detected with M-mode, 2-dimensional real-time or pulsed-wave Doppler echocardiography.

Normal flow velocities for right and left atrial outflow, right and left ventricular outflow, the aorta, and pulmonary artery were determined. Peak flow velocities for right and left atrial outflow occurred during the rapid filling phase and were higher toward the mitral valve (mean, 0.70 ± 0.24 m/s) than toward the tricuspid valve (mean, 0.49 ± 0.17 m/s). Peak flow velocities in the right and left ventricular outflow tracts were similar (means, 0.81 ± 0.10 m/s and 0.75 ± 0.39 m/s, respectively). Peak flow velocities in the pulmonary artery (mean, 1.09 ± 0.42 m/s) and aorta (mean, 1.01 ± 0.29 m/s) were similar, although flow peaked earlier in systole in the aorta than in the pulmonary artery.
Clinical studies of fish blood: Importance of sample collection and measurement techniques
Authors: Heming Thomas A.
Published: February 2025

Effects of blood sample collection and measurement techniques were assessed for blood gas tensions, acid-base status, and hematologic and plasma biochemical values of rainbow trout. Blood samples were collected via intraaortic cannulae from immersed, unrestrained fish and from emersed, restrained fish. The samples were analyzed at either fish body temperature (10 to 14 C) or clinical blood analyzer temperature (37 C); results obtained at 37 C were back-adjusted to fish body temperature, using standard mammalian temperature-correction factors. Fish emersion and handling for 30 seconds significantly (P < 0.05) altered blood Pco2, acid-base status, and hematologic and plasma biochemical values. The results were consistent with respiratory acidosis and hemoconcentration. The use of mammalian temperature-correction factors for determination of fish blood gas tensions and acid-base status yielded values that were significantly (P < 0.05) different from those measured directly at fish body temperature.