bluuebunny/crossref_metadata_2025 huggingface dataset:
Culture-positive persistence and serum agglutinating antibody response after intrauterine inoculation of Haemophilus somnus in virgin heifers
Authors: Hoblet K. H. , Haibel G. K. , Kowalski J. J. , Rojko J. L.
Published: February 2025

Viable Haemophilus somnus of reproductive tract origin (OSU-1167) was inoculated transcervically into the uterus of 6 virgin heifers. Five heifers were sham-inoculated (intrauterine) with sterile mycoplasmal medium and served as controls. After inoculation and observation, all heifers had nasal and vaginal vestibular swab specimens and serum obtained periodically for 44 days. Signs of systemic illness were not detected. On the day after inoculation, all inoculated heifers had signs of vulvovaginitis, whereas none of the control heifers had similar signs (P < 0.002). Haemophilus somnus was not isolated from any nasal or vaginal vestibular swab specimens obtained before inoculation or from any nasal swab specimens obtained after inoculation. During the 44 days after inoculation, H somnus was isolated from 25 of 54 vestibular specimens obtained from inoculated heifers and from 3 of 45 specimens obtained from controls (P < 0.02). Vulvovaginal lesions were associated with vestibular isolation of H somnus in 23 of 25 (92%) such isolations from inoculated heifers; lesions were never associated with concurrent isolation of H somnus in controls. All heifers had H somnus microagglutination test (mat) titer ≤ 256 against a commercially prepared H somnus antigen at the beginning of the study. Considered as groups, neither inoculated nor control heifers achieved fourfold increases in mat titer during the 44 days after inoculation. When compared by day of sample collection, inoculated heifers did have significantly (P < 0.04) lower geometric mean titer at 7 days after inoculation than did control heifers when tested by use of a commercially prepared antigen. It was concluded that H somnus OSU-1167 induced vulvovaginitis, but infection was not reliably documented by increased mat titer.
Natural parvovirus infection in laboratory rabbits
Authors: Metcalf John B. , Lederman Muriel , Stout Ernest R. , Bates Robert C.
Published: February 2025

Laboratory rabbits from various commercial and private sources were found to have high serum antibody titers specific for lapine parvovirus (lpv). By both immunofluorescence and hemagglutination inhibition assays, 75% of these sera were positive for lpv. This finding, together with the recovery of lpv from kidneys of neonatal rabbits, suggested that lpv infection is common in commercially available rabbits in the United States. It was concluded that use of infected rabbits could interfere with research in which rabbit cell cultures or in vitro immunologic assays are used.
Antigenic relationships among field isolates of Tritrichomonas foetus from cattle
Authors: Huang Juch-Chin , Hanks Donald , Kvasnicka William , Hanks Maynard , Hall Mark R.
Published: February 2025

Analysis of protein and antigen profiles of Tritrichomonas foetus isolates from cattle from 5 western states was accomplished by sodium dodecyl sulfate polyacrylamide-gel electrophoresis, immunoblot, immunoprecipitation, and fluorography techniques. Total protein profiles of all isolates were compared by Coomassie brilliant blue staining of T foetus protein samples prepared by 4 protein-extraction methods. Antigenic tritrichomonas proteins were identified by immunoblot assay with polyclonal bovine or rabbit anti-T foetus serum. Additionally, [14C]glucosamine-labeled T foetus was used for total and antigenic glycoprotein analyses. Detectable differences in the composition of total proteins or antigenic tritrichomonal proteins were not observed among all isolates. However, intensity differences in some antigenic protein bands were apparent. Bovine and rabbit sera from immunized animals possessed antibodies to the same antigenic tritrichomonal proteins. Each T foetus isolate contained 4 to 7 molecular weight size classes of glycoprotein, which were labeled by [14C]glucosamine; however, only 3 to 4 glycoproteins were identified as antigens by bovine or rabbit antiserum.
Antibodies to bovine serum albumin in swine sera: Implications for false-positive reactions in the serodiagnosis of African swine fever
Authors: Escribano J. M. , Pastor M. J. , Sánchez-Vizcaíno J. M.
Published: February 2025

Antibodies to bovine serum albumin were detected in swine sera by use of an immunoblotting technique. Such sera had false-positive reactions, as determined by results of African swine fever virus serodiagnostic techniques when bovine serum albumin was a contaminant in the soluble cytoplasmic antigen obtained from infected cells cultured in the presence of bovine serum.

The soluble cytoplasmic antigen obtained from cell cultures infected with African swine fever virus in the presence of porcine serum did not react with the false-positive sera and, therefore, was used for African swine fever virus serodiagnostic methods, with 0% false-positive results.
Prostaglandin and thromboxane concentrations in plasma and lung lavage fluids during sequential infection of vaccinated and nonvaccinated calves with bovine respiratory syncytial virus
Authors: Gershwin L. J. , Giri S. N. , Stewart R. S. , Chen J.
Published: February 2025

The potential action of immunologic reactions and mediators released during the course of bovine respiratory syncytial virus infection in pathogenesis of the ensuing disease process was examined in an experimental infection study. Prostaglandin (pg) E2, pgf2α, 6-keto-pgflα, and thromboxane B2 (TxB2) concentrations were quantitated in plasma and lung lavage fluid by radioimmunoassay at 3- to 4-day intervals during a primary and secondary virus infection of vaccinated, nonvaccinated, and control (mock-infected) calves. A significant increase in the plasma pge2 concentration for the nonvaccinated calves was noticed on day 3 after primary infection and on day 7 after secondary infection. The pgf2α plasma concentrations increased significantly for the nonvaccinated groups on day 10 after primary infection. Plasma 6-keto-pgfla concentrations increased for nonvaccinated and vaccinated calves 3 days after the secondary infection. Plasma txb2 concentrations during the primary exposure did not vary significantly. However, 14 days after the secondary exposure, both experimental groups had concentrations significantly greater than did the control group. Lung lavage fluid concentrations of TxBz had peaks of activity 7 days after primary and secondary viral infections for the nonvaccinated group. Increases in plasma PG concentrations corresponded variably with disease expression, whereas plasma TxB2 concentrations did not have any correlation with disease expression. However, there was a significant correlation between TxB2 concentration in lung lavage fluid of the nonvaccinated group with disease expression 7 days after primary and secondary virus infection. The potent physiologic effects of PG and TxB2 and their demonstrated production in this infection study suggest that these mediators and the effects of vaccination on their production should be considered as a potentially important factor in the natural disease process.
Long-term complete chimerism and stable hematopoiesis in Beagles after fetal liver hematopoietic stem cell transplantation
Authors: Cain G. R. , Champlin R. E.
Published: February 2025

Karyotype analysis of bone marrow cells was performed from 6 Beagles that had received sex-mismatched fetal liver hematopoietic stem cell grafts 2.4 to 6.5 years earlier. Two dogs received dog leukocyte antigen-matched fetal liver cells and 4 received dog leukocyte antigen-mismatched cells. In each dog, all 25 evaluated metaphase spreads were of donor genotype. All dogs had normal hemograms and repopulation of bone marrow and no dog developed graft-vs-host disease.
Pharmacokinetics and metabolic inertness of doxycycline in calves with mature or immature rumen function
Authors: Riond Jean-Luc , Tyczkowska Krystyna , Riviere J. Edmond
Published: February 2025

The pharmacokinetic determinants of doxycycline were calculated after a single iv administration of the drug (20 mg/kg of body weight) in 5 Angus calves with mature rumen function and 4 Holstein calves with immature rumen function. Doxycycline disposition was best described by means of an open 2-compartment model. Median elimination half-life was 14.17 hours (Angus) and 9.84 hours (Holstein). Mean (± SEM) total body clearance was 1.07 (± 0.06) and 2.20 (± 0.21) ml/min/kg in Angus and Holstein calves, respectively. Mean extent of doxycycline binding to serum proteins was 92.3% (± 0.8%). The large steady-state volume of distribution (1.31 ± 0.11 L/kg in Angus and 1.81 ± 0.24 L/kg in Holstein calves), despite the small free fraction in serum, suggested a relatively unrestricted access of drug into the intracellular compartment and/or appreciable tissue binding. Results of mass spectrometric analysis of serum and urine from calves administered doxycycline iv revealed absence of biotransformation, because only parent drug could be detected. Thus, doxycycline may be a valuable antibiotic for use in food animals pending further studies on tissue residues, safety, and efficacy.
Detection of colonies of Anaplasma marginale in salivary glands of three Dermacentor spp infected as nymphs or adults
Authors: Stiller David , Kocan Katherine M. , Edwards Wanda , Swing S. A. , Hair Jakie A. , Barron Selwyn J.
Published: February 2025

Salivary glands from males of 3 Dermacentor species (D andersoni, D variabilis and D occidentalis) that were infected with either the Virginia or Idaho isolate of Ana-plasma marginale as nymphs or adults were examined for colonies of A marginale by use of light and electron microscopy. Prior to dissection of salivary glands, exposed ticks were held at 25 C for 15 to 18 days, followed by a 3-day incubation at 37 C. Ticks of 2 species transmitted A marginale to calves; the third tick species was confirmed infected by demonstration of typical colonies in tick gut cells, but transmission was not attempted; Colonies of A marginale were seen with light microscopy in salivary glands of all 3 species of ticks; they were located in acinar cells that contained simple granules. Colonies varied morphologically from small, compact ones to larger structures that contained distinct organisms and often were adjacent to the host cell nucleus. Electron microscopy confirmed that the colonies were rickettsial organisms. Morphologic features of A marginale varied and included reticulated forms, forms with electron-dense centers, and small particles; these various forms were similar to those described previously in midgut epithelial cells of ticks. We believe that the organism seen within tick salivary glands may replicate in the glands before its transmission to the vertebrate host.
Influence of cage size on heart rate and behavior in rhesus monkeys
Authors: Line Scott W. , Morgan Kathleen N. , Markowitz Hal , Strong Sharon
Published: February 2025

We studied 6 singly caged adult female rhesus monkeys to determine whether increased cage size had any effect on behavior or heart rate. Two monkeys at a time were placed in cages 40% larger than their standard cage for 1 week on 2 occasions, using a counter-balanced design. Direct behavioral observations were performed 75 minutes/week on each monkey. Heart rate and general activity were monitored 35 hours/week by a telemetry system. Statistically significant differences were not found in aggressive, submissive, abnormal, or self-abusive behavior, nor in time spent in the front half of the cage, duration of grooming, looking at the observer, or stereotyped or nonstereotyped locomotion. Vocalizations increased the first time in the larger cage, but not the second, and decreased upon the second return to the standard cage. Differences with respect to cage size were not found in heart rate or activity level, although there were significant variations at different times of day. We conclude that modest increases in cage size are unlikely to enrich the environment of singly caged laboratory primates.
Effect of incorporation of serum from dogs with renal impairment on canine erythroid bone marrow cultures
Authors: Petrites-Murphy M. B. , Pierce Kenneth R. , Fisher James W.
Published: February 2025

Serum from dogs with surgically induced renal impairment was incorporated into the medium for erythroid bone marrow cultures. A significant correlation was found between serum activities of erythropoietin and numbers of erythroid colony-forming units grown in culture. Serum creatinine concentrations had no correlation, and serum parathyroid hormone activities had a negative correlation with numbers of erythroid colony-forming units that was below the level of significance. Purified 1-84 parathyroid hormone added to bone marrow cultures was found to be stimulatory to erythroid colony-forming unit growth in higher concentrations, but decreased the number of burst-forming units. Unmeasured substances in the canine serum appeared to have a greater effect on the canine erythroid bone marrow cultures than did creatinine or parathyroid hormone values.
Comparison of arrhythmogenic doses of epinephrine in heartworm-infected and noninfected dogs
Authors: Venugopalan C. S. , Holmes E. , O'Malley N. A.
Published: February 2025

The arrhythmogenic dose of epinephrine (ade) was determined in heartworm-infected and noninfected (control) dogs during thiamylal-induced and halothane-maintained anesthesia to assess the myocardial sensitization. The ade in heartworm-infected dogs (2.42 ± 0.26 μg/kg of body weight) was significantly lower than that for the controls (3.36 ± 0.29 μg/kg). After 2 weeks, ade was determined again in these dogs after atropine treatment. Atropine treatment lowered the ade to 1.76 ± 0.33 μg/kg and 1.77 ± 0.19 μg/kg in heartworm-positive and -negative dogs, respectively. After 2 weeks more, the ade was determined after administration of prazosin, an α1 antagonist. Only 2 of 6 controls and 3 of 6 heartworm positive dogs had arrhythmias after a threefold increase of ade. The mean ade in the dogs that responded to treatment were 7.4 μg/kg and 7.2 μg/kg for heartworm-positive and -negative dogs, respectively. The finding of this study indicated that ade in heartworm-infected dogs were lower than those in the control dogs, which makes the heartworm-infected dogs more vulnerable to arrhythmia during anesthesia. Atropine did not protect the dogs of either group. However, prazosin protected the dogs of both groups by significantly increasing the threshold of the ade. On the basis of our findings, to reduce the risk of arrhythmia, we suggest that routine screening of dogs for heartworm infection be done before anesthetics are used.
Brucella abortus-specific immunoglobulin isotypes in serum and vaginal mucus from heifers vaccinated with Brucella abortus salt-extractable proteins and challenge exposed with virulent Brucella organisms
Authors: Hall Stephen M. , Confer Anthony W.
Published: February 2025

Serum and vaginal Brucella-specific immunoglobulin isotypes (IgGl, IgG2, IgM, and IgA), obtained from 62 crossbred beef heifers vaccinated with Brucella abortus salt-extractable proteins and subsequently challenge exposed with B abortus S2308, were studied. Brucella-specific IgG antibodies and Brucella-specific immunoglobulin isotypes were quantitated by a fluorometric immunoassay. Serum and vaginal immunoglobulin responses were evaluated as a method of distinguishing infected from noninfected heifers. Rivanol precipitation, complement-fixation, buffered-antigen brucellosis tests and an elisa were performed on sera.

For immunoglobulin isotypes, vaccinated heifers had mean antibody responses higher than baseline mean antibody responses for at least 31 weeks after vaccination. After challenge exposure, significant differences (P > 0.05) were not detected between mean antibody responses of vaccinated and nonvaccinated heifers.

Vaginal Brucella-specific antibody responses did not correlate with protection from disease. Vaginal Brucella-specific IgM was detected only at the time of abortion. Vaginal IgA appeared specific for identification of virulent B abortus infection.

All serotests appeared adequate in distinguishing baseline titers from titers of heifers that had aborted and were considered bacteriologic culture-positive. Results of serotests neither consistently distinguished vaccinates from challenge-exposed cattle nor distinguished heifers that were challenge exposed, had aborted, and were considered bacteriologic culture-positive adequately from heifers that were challenge-exposed, had not aborted, and were considered bacteriologic culture-negative. Brucella-specific IgA appeared to be the most effective in distinguishing vaccinated heifers from challenge-exposed heifers and heifers that were challenge-exposed and had aborted, from heifers that were challenge exposed and had not aborted. Brucella-specific serum IgA was detected up to 13 weeks after abortion.
Endobronchial inoculation of various doses of Haemophilus (Actinobacillus) pleuropneumoniae in pigs
Authors: van Leengoed Leo A. M. G. , Kamp Elbarte M.
Published: February 2025

Twelve-week-old specific-pathogen-free pigs were inoculated deep in the bronchi with Haemophilus (Actinobacillus) pleuropneumoniae strain 13261 in doses ranging 8 × 101 to 9 × 107 colony-forming units (cfu). Pigs that survived infection were euthanatized and examined 48 hours after inoculation. The relationship between dose and severity of disease was evaluated clinically and the weight of pneumonic lesions was compared. The relationship between infection dose and weight of pneumonic lesions proved to be unimodal and not linear. Inoculation of 104 cfu of strain 13261 resulted in severe pneumonic lesions and mortality of 29%. In contrast, death was not observed after inoculation with 106 cfu of strain 13261 and pneumonic lesions were less severe (P < 0.05). An infective dose of 103 cfu induced pneumonic lesions that tended (not statistically significant) to be less severe than those induced by a dose of 104 cfu.

The peak fever response in all infected pigs was observed from 6 to 12 hours after inoculation. Leukocytosis developed within 12 hours after inoculation, because of an increase of neutrophilic granulocytes. Thereafter, wbc count decreased owing to lymphopenia. Serum iron concentration decreased 80% after inoculation, and zinc concentration decreased 54%.
Relationship between dietary protein concentration and serum trypsin-like immunoreactivity in dogs
Authors: Carro Teresita , Williams David A.
Published: February 2025

Serum trypsinogen concentration was studied in 6 adult mixed-breed dogs randomly fed diets containing 6.8, 31.4, or 39.7% protein (dry weight) for 3 weeks each. Blood was collected on days 20, 21, and 22 of each feeding period, and serum trypsinogen concentrations were determined by radioimmunoassay of trypsin-like immunoreactivity (tli). Mean serum tli concentrations for each dog fed each diet were compared. A significant (P < 0.05) positive linear relationship (P < 0.02) was determined between serum tli concentrations and the percentage of dietary protein. Mean serum tli concentrations for each dog fed all diets ranged from 5.7 to 20.2 μg/L.
Commercially available recombinant human thyroid-stimulating hormone effectively stimulates total and free thyroxine concentrations in Quaker parrots (Myopsittamyopsitta monachus), including at low doses and after freezing
Authors: Thielen Lauren E. , Hoppes Sharman , Di Girolamo Nicola
Published: February 2025

Objective

To develop a protocol for thyroid-stimulating hormone (TSH) stimulation testing in psittacine birds using a thyrotropin alfa (Thyrogen; Sanofi).

Methods

Quaker parrots (Myopsitta monachus) were randomized to receive an IM injection of freshly reconstituted high-dose recombinant human TSH (rhTSH; 8 parrots), frozen high-dose rhTSH (8), frozen low-dose rhTSH (8), or saline (8). Total T4 (TT4), free T4 (FT4), T3, and TSH were measured pre- and 4 hours postinjection.

Results

TSH stimulation testing was completed in 31 of the 32 birds. Thyroid-stimulating hormone measurement confirmed proper administration of rhTSH. Median TT4 at baseline in the population was 0.14 μg/dL (range, 0.03 to 0.33 µg/dL). Poststimulation, the median TT4 in rhTSH-treated parrots was 1.31 µg/dL (0.29 to 1.98 µg/dL) versus 0.09 µg/dL (0.04 to 0.14 µg/dL) in control parrots. All parrots administered rhTSH had an increase in TT4 (minimum, 3.5-fold) and FT4 (minimum, 2.2-fold) from baseline but not in T3. Parrots administered saline had no increase in TT4, FT4, or T3. Postinjection concentrations of TT4, but not of FT4 or T3, showed no overlap between controls and rhTSH-treated parrots.

Conclusions

TSH stimulation testing performed with fresh and frozen rhTSH for 3 months is feasible and safe and results in a significant increase in TT4 in Quaker parrots. Total T4 should be the preferred outcome measure for TSH stimulation testing in parrots.

Clinical Relevance

Thyrogen can be used at doses as low as 0.01 mL (73 µg/kg) for TSH stimulation tests in Quaker parrots and can be frozen in aliquots to perform more tests per vial.
Degenerative Myelopathy in a Cat
Authors: Mesfin G. M. , Kusewitt D. , Parker A.
Published: February 2025

Degenerative myelopathy was diagnosed in a 6-year-old cat that had progressive ataxia, posterior paresis, and loss of conscious proprioception over a period of 8 months. Corticosteroid therapy did not alleviate clinical signs, and the cat was euthanatized. Microscopic examination of the spinal cord revealed diffuse degeneration of myelin attended by marked astrocytosis. The degenerative changes were most marked in the thoracolumbar segment. The cause of the degenerative lesions was not apparent.
Strongyloides stercoralis-like Infection in a Dog
Authors: Malone J. B. , Breitschwerdt E. B. , Little M. D. , Ochoa R. , Wolf K. A.
Published: February 2025

Helminths similar to Strongyloides stercoralis were recovered from the jejunum and ileum of a 6-month-old Boston Terrier that was shedding unusually large eggs, both unembryonated and embryonated, as well as first-stage larvae in fresh feces. Clinical signs included stunting, mucoid and blood-flecked feces, radiographic evidence of diffuse interstitial pulmonary infiltrate, focal dermatitis, and anemia. Decreased intestinal absorption of carbohydrate was found by means of the oral glucose and oral lactose tolerance tests. Serum protein and calcium values were decreased. At necropsy, histopathologic findings included uneven crypt hyperplasia and mild inflammation in the ileum and jejunum, diffuse interstitial pulmonary inflammation, Kupffer's cell hyperplasia in the liver, and generalized lymph node hyperplasia.
A Technique for Management of Traumatic Rupture of the Equine Suspensory Apparatus
Authors: Wheat J. D. , Pascoe John R.
Published: February 2025

Problems involving the management of acute traumatic rupture of the equine suspensory apparatus include loss of blood flow to the foot, proper immobilization, and pressure sores from casts. A technique utilizing a board splinting device attached to the affected limb at the toe and subsequent corrective shoe support provides immobilization, prevents dropping of the fetlock, can be applied to the standing animal, and allows frequent changing of the bandages, if necessary.
Hyperthermia for Treatment of Ocular Squamous Cell Tumors in Cattle
Authors: Kainer Robert A. , Stringer John M. , Lueker David C.
Published: February 2025

Fifty-six benign ocular squamous cell tumors and 20 squamous cell carcinomas were subjected to hyperthermia (50 C for 30 sec/cm2 of tumor surface) created by radio-frequency current from an electrothermal device. Of the 76 tumors, 60 (49 benign and 11 malignant) regressed completely following a single treatment. Among the remaining 16 tumors, 7 benign tumors and 2 squamous cell carcinomas regressed completely following a second treatment, whereas 5 carcinomas regressed partially and 2 carcinomas failed to respond after the second treatment. Thus, 90.8% of the tumors regressed completely, and all of these sites were free of visible lesions 5½ months after the initial treatment. Of 69 sites that were tumor-free at 5½ months, 42 were available for observation at 1 year; all 42 sites were free of tumor. Squamous cell tumors developed subsequently at other ocular or adnexal sites in 27% of the treated cattle.
Multifocal Ocular Histoplasmosis in a Dog and Cat
Authors: Gwin Robert M. , Makley Torrence A. , Wyman Milton , Werling Kathryn
Published: February 2025

In two cases of naturally occurring disseminated histoplasmosis, multifocal inflammatory lesions were seen in the posterior segment of the eyes. Histologic examination of both animals revealed lesions of active choroiditis (cat) and retinitis (dog) in association with numerous Histoplasma capsulatum.
Transfixation Pinning of Proximal Tibial Fractures in Calves
Authors: Hamilton G. F. , Tulleners E. P.
Published: February 2025

Tibial fractures in three newborn beef calves were reduced and stabilized by transfixation pinning. Return to normal function was rapid in two calves. One calf acquired septic arthritis of the stifle and was later euthanatized; however, the fracture had healed. Good radiographic and clinical evidence of stability was evident in 4 to 6 weeks, at which time the pins were removed.
Premature Closure of the Distal Radial Physis in Two Dogs
Authors: Olson Neil C. , Brinker Wade O. , Carrig Colin B.
Published: February 2025

Premature closure of the distal radial physis was diagnosed in two dogs. In one dog, the premature closure was symmetric; in the other, it was asymmetric. Lameness, elbow subluxation, distended elbow joint capsule, forelimb muscle atrophy, and a shortened radius and ulna had developed in each dog. Carpal valgus and outward rotation of the paw had developed in the dog with asymmetric closure. Surgical treatment resulted in marked improvement of forelimb function in both dogs.
Pharmacotherapeutics of Chloramphenicol in Veterinary Medicine
Authors: Sisodia Chatur S.
Published: February 2025

Since its discovery in 1947, chloramphenicol has enjoyed a prominent place in the veterinarian's drug arsenal. Some of the reasons for its popularity are: (1) Antimicrobial activity—effective against a variety of infective pathogens, including staphylococci, salmonellae, pasturellae, Bordetella, Haemophilus, coliform organisms, chlamydiae, and rickettsiae, many of which may be resistant to other antimicrobial agents; (2) Kinetic properties—allowing production and maintenance of effective therapeutic concentrations in body fluids and tissues, with a practicable dosage schedule in most species; (3) Safety—toxic reactions to chloramphenicol encountered thus far in animals have not warranted any serious limitations on its use in veterinary medicine.
Disposition of Oxytetracycline in the Bovine Genital Tract: Systemic vs Intrauterine Administration
Authors: Masera Jesse , Gustafsson Borje K. , Afiefy Monier M. , Stowe Clarence M. , Bergt Greg P.
Published: February 2025

The distribution of oxytetracycline (otc) in genital tissues, uterine secretions, milk, and plasma was examined after systemic (im) and intrauterine (iu) administration at various intervals after administration in normal-cycling diestrous cows and in cows with chronic endometritis. The im route resulted in otc concentrations in endometrium and uterine secretions that were higher than were concentrations in plasma and milk over 72 hours. Twenty-four hours after im administration, otc concentrations in tissues of the genital tract (ovaries, oviducts, myometrium, serosa, cervix, and vagina), muscles, and udder were 100% higher than were concentrations in plasma. The iu administration resulted in a high concentration in the endometrium and uterine cavity over the 72-hour posttreatment period. The plasma concentrations were considerably lower than after the im injection, indicating a lesser absorption from the uterus than from the im injection site. This was more pronounced in cows with endometritis. Elimination from plasma and milk occurred in 24 hours. Contrary to results of the im route, the iu route did not result in detectable concentrations in genital tissues apart from the endometrium 24 hours after administration.
Mechanisms of Adverse Drug Reactions and Interactions in Veterinary Medicine
Authors: Eckhoff Gary A.
Published: February 2025

Rapid advances in research in basic pharmacology and the productivity of the pharmaceutical industry have resulted in the introduction of many new drugs for the veterinary profession. The availability of such a large number of drugs has stimulated their concomitant use with the hope that maximum therapeutic effectiveness will be achieved. Indeed, modern therapeutics in veterinary medicine often necessitates the simultaneous administration of several drugs. With the increased use of multiple drug therapy has come the problem of drug interactions, which necessitates greater professional awareness and responsibility on the part of the veterinarian. Drug interactions are essentially a problem of modern medicine.
Persistence of Pseudorabies Virus in Infected Swine
Authors: Beran George W. , Davies E. Bryan , Arambulo Primo V. , Will Loren A. , Hill Howard T. , Rock Daniel L.
Published: February 2025

The persistence of pseudorabies virus (prv) in pigs clinically recovered from the disease was detected by culture of tissue fragments. Weanling pigs were infected by intranasal instillation of 200,000 plaque-forming units of a strain of prv isolated from sick pigs in Iowa, and virus was recovered from them 6 weeks to 13 months later. Tonsil, trigeminal ganglia, or pooled trigeminal ganglia and olfactory and optic nerve tissue were most consistently the source of virus.

The tissue-fragment culture technique was compared with a co-culture technique for detection of virus in tissue specimens from the recovered pigs. Use of these procedures provided the means to detect prv in pigs for periods longer than previously recognized.
Tissue Residue Depletion and Recycling of Sulfamethazine in Swine
Authors: Whipple D. M. , Samuelson G. , Heath G. E. , Showalter D. H.
Published: February 2025

Sulfamethazine was fed to weanling pigs at the rate of 100 g/ton of ration for 98 days to investigate the depletion rate of the drug from the plasma and edible tissues of swine. The mean plasma concentration of sulfamethazine for 21 treated pigs peaked at 10.8 ppm on day 77 of the 98-day treatment period. The concentration of sulfamethazine in kidney, liver, skeletal muscle, and subcutaneous fat was at or below 0.1 ppm within 7 days after withdrawal of medicated feed. Depletion of sulfamethazine from the tissues and plasma of the treated pigs showed a linear relationship with time when values were plotted on a semilogarithmic graph. Six of seven untreated pigs that were placed in the pens formerly occupied by the treated pigs accumulated drug residues in their kidney and liver tissues. Sulfamethazine concentrations in these tissues were at or above 0.1 ppm in 5 to 14 days.
Immunogenicity and Safety of an Inactivated Vaccine for the Prevention of Rhinotracheitis, Caliciviral Disease, and Panleukopenia in Cats
Authors: Povey R. Charles , Koonse Howard , Hays Merlin B.
Published: February 2025

An inactivated vaccine for the prevention of feline viral rhinotracheitis (fvr), caliciviral disease, and panleukopenia has been developed. The efficacy of this vaccine for protection against fvrand caliciviral disease was assessed by vaccination of 41 cats and challenge of immunity with either fvrvirus or feline calicivirus (fcv), strain 255. All vaccinated cats developed serum neutralizing (sn)antibody (mean sn50 1:45.5) to fvrvirus, and 95% developed antibody (mean sn50 1:8.1) to fcv, strain 255. Following fvrchallenge, the mean cumulative score of clinical signs was 1.1 for vaccinated cats versus 22.2 for controls. Following fcvchallenge, the mean scores were 2.7 for vaccinates and 17.5 for controls. Immunogenicity of the panleukopenia fraction was demonstrated by the development of neutralizing antibody titers >1:8 in all 21 vaccinates that were tested.
Volvulus of the Large Colon in the Horse
Authors: Barclay William P. , Foerner Joseph J. , Phillips Thomas N.
Published: February 2025

Volvulus of the large colon was diagnosed at surgery in 25 horses during a 4-year period. Two horses had a recurrence of the condition after successful correction. Mucosal necrosis was found to be a grave prognostic sign, as it was a consistent finding in horses that died at the time of surgery. Long-term colon dysfunction was not clinically evident in surviving horses.
Salmonellosis and Arizonosis in the Reptile Collection at the National Zoological Park
Authors: Cambre Richard C. , Green D. Earl , Smith Elizabeth E. , Montali Richard J. , Bush Mitchell
Published: February 2025

The prevalence of Salmonella and Arizona organisms in the reptile collection at the National Zoological Park was investigated. Culture of specimens from 317 reptiles, while live or at necropsy, yielded 117 positive results, for an overall infection rate of 37%. Snakes had the highest rate, 55% (69 of 125); lizards had an intermediate rate, 36% (46 of 129); and turtles and tortoises had the lowest rate, 3% (2 of 63). Twenty-four serotypes of Salmonella enteritidis, 1 of S choleraesuis, and 39 of Arizona hinshawii were represented.

While clinical illness was never directly attributed to infection with these organisms, pure cultures of Salmonella and Arizona were recovered at necropsy from some reptiles with gross and/or histologic lesions in the gastrointestinal tract, liver, spleen, and blood vessels. However, numerous other concurrent diseases and management problems were often considered the immediate cause of death, with Salmonella and Arizona being ready and significant opportunistic pathogens contributing to the demise of the reptiles.
Edema Disease in a California Sea Lion
Authors: Diamond Sheldon S. , Raflo Charles P. , Beleau Marshall H. , Cadwell Gaye A.
Published: February 2025

Edema disease, similar to that occurring in swine, was diagnosed in a California sea lion (Zalophus californianus). The prominent features included a thickened, edematous stomach wall and generalized fibrinoid necrosis of arterioles. A beta-hemolytic Escherichia coli, serotype 0147:Κ•:Η52, was the predominant organism isolated from the gastrointestinal tract. The organism caused fatal infection when administered orally and intraperitoneally to mice.
Hypoglycemia-Ketonemia in a Pregnant Bitch
Authors: Jackson R. F. , Bruss Μ. L. , Growney P. J. , Seymour W. G.
Published: February 2025

A case of hypoglycemia accompanied by ketonemia and ketonuria in a pregnant dog was investigated. Temporary remission of signs occurred following parenteral administration of glucose. Permanent remission followed delivery of the fetuses. Abnormal results were not obtained from 5 carbohydrate challenge tests performed on the patient subsequent to the delivery.
Warfarin Anticoagulation in the Horse
Authors: Scott E. A. , Byars T. D. , Lamar A. Μ.
Published: February 2025

The hematologic and clinical effects of anticoagulation with warfarin were documented in 4 horses. All of the animals had thrombophlebitis (external jugular vein). Measures of coagulation were monitored, with a prothrombin time of 1.5 to 2.5 x base-line value being used as the effective range of anticoagulation.

Recanalization was achieved in 2 of 4 cases. Hemorrhage, both subcutaneous and through a surgical incision, was a complication. Vitamin K1, an antidote to warfarin toxicosis, was administered intravenously to reverse anticoagulation and to control hemorrhage.
Pancreatic Function in Domestic Cats with Pancreatic Fluke Infection
Authors: Fox John N. , Mosley John G. , Vogler George A. , Austin James L. , Reber Howard A.
Published: February 2025

Thirty-one of 290 cats (10.7%) from the area around St Louis, Mo, were infected with Eurytrema procyonis. In some cats, the pancreas was severely affected, with almost complete atrophy and fibrous replacement of the gland. Both bicarbonate and protein secretions were impaired, although clinically evident pancreatic insufficiency was not seen.
Torsion of the Spermatic Cord in a Horse
Authors: Pascoe John R. , Ellenburg T. V. , Culbertson M. R. , Meagher D. M.
Published: February 2025

A 360-degree torsion of the left spermatic cord was diagnosed in a 2½-year-old Quarter Horse colt. Clinical signs included abdominal discomfort, with slight elevations in heart and respiratory rates. The scrotum on the left side was moist and edematous. The left testicle was enlarged, firm, and retracted slightly toward the abdominal cavity. The colt resented palpation of the testicle. On rectal palpation, the left vaginal ring and the structures passing through the ring were edematous and painful to pressure. Surgical correction was achieved by emasculation. The tail of the epididymis and an elongated portion of the body of the epididymis were attached to the left testicle by an unduly long mesorchium. The caudal ligament of the epididymis and the proper ligament of the testis were elongated. These anatomic variations may have predisposed to torsion of the spermatic cord.
Brainstem Auditory Evoked Response in the Diagnosis of Inner Ear Injury in the Horse
Authors: Marshall A. E. , Byars T. D. , Whitlock R. H. , George L. W.
Published: February 2025

Brainstem auditory evoked response (baer) testing was done to evaluate inner ear/VIIIth cranial nerve (CN8) function in the horse. The baer test consisted of stimulating the auditory system with clicks and recording far-field responses of the brainstem auditory components via cutaneous electrodes and a signal averaging system. The normal response was shown to be a series of waves occurring within the first 10 msec after the stimulus click. Functional loss of the auditory receptor organ (cochlea) or CN8 results in loss of the entire response on the side of the injury. Because of the anatomic relationships of the peripheral auditory and vestibular systems, trauma to one will injure the other. Therefore, auditory testing (baer tests) may be used to advantage in the diagnosis of peripheral vestibular disease.

The baer test was used in a horse that had signs suggestive of vestibular dysfunction or a brain lesion. The test helped to demonstrate a unilateral inner ear/CN8 lesion and to discount the probability of a more central lesion.
Waste Anesthetic Gas Exposures to Veterinarians and Animal Technicians
Authors: Wingfield Wayne E. , Ruby Darrell L. , Buchan Roy M. , Gunther Bobby J.
Published: February 2025

A survey of veterinarians was conducted in an 11-county region of eastern Colorado to determine the extent of usage of inhalation anesthetics and to measure exposures of veterinarians and their assistants to waste anesthetic gases. The survey indicated that inhalation anesthetics were used in 80.8% of the 210 practices. Exposures to waste anesthetics in veterinary practices were far less than reported in human hospitals. Waste anesthetic concentrations were affected by size of the patient, type of breathing system, and use of scavenging systems. Dilution ventilation had no effect on breathing zone concentrations. The endotracheal tube and occasionally the anesthetic machine were the major sources of leakage of anesthetic gases.
Effect of Bovine Viral Diarrhea Virus on Conception in Cattle
Authors: Whitmore H. L. , Zemjanis R. , Olson J.
Published: February 2025

Sixty adult dairy cows were used to study the effect of bovine viral diarrhea (bvd) virus on conception when inoculated with the virus within 2 hours after breeding. Fifteen cows were assigned at random to each of 4 groups. Group I (control) cows were given 3 ml of diluent in the uterus; group II (seropositive) cows were given 3 ml of bvd virus in the uterus; group III (seronegative) cows were given 3 ml of bvd virus in the uterus; and group IV (seronegative) cows were given 3 ml of bvd virus orally and 3 ml intranasally. At 35 days after breeding, the cows were slaughtered, their reproductive tracts were recovered, and pregnancy rates were recorded.

The pregnancy rates for groups I, II, III, and IV were 67%, 60%, 27%, and 67%, respectively. The group III pregnancy rate was significantly lower (P < 0.05) than that for the control group. However, the similarity of rates for groups I, II, and IV indicates that bvd virus does not inhibit conception when cattle are infected by natural routes or when virus is infused into the uterus of seropositive cows at the time of breeding. These results indicate that bvd virus is not a major cause of repeat breedings in cattle.
Hypoglycemia in Four Dogs with Sepsis
Authors: Breitschwerdt Edward B. , Loar Andrew S. , Hribernik Thomas N. , McGrath Renee K.
Published: February 2025

Hypoglycemia in association with severe sepsis was diagnosed in 4 dogs. Other causes of hypoglycemia were considered and eventually ruled out. The use of insulin/giucose determinations were not of consistent value to confirm or eliminate the presence of an insulin-secreting tumor. Successful treatment of the septic conditions in 2 dogs coincided with a return to normal blood glucose content.
Mycobacterium paratuberculosis in the Semen and Genital Organs of a Semen-Donor Bull
Authors: Larsen A. B. , Stalheim O. H. V. , Hughes D. E. , Appell L. H. , Richards W. D. , Himes E. M.
Published: February 2025

Mycobacterium paratuberculosis, the cause of Johne's disease, was isolated from the feces of a donor bull in an artificial insemination stud. During isolation and observation for 21 months, the organism was recovered from all of 26 fecal samples and from 8 of 31 semen samples. At necropsy, it was isolated from the intestine and adjacent lymph nodes, lung, spleen, seminal vesicles, and prostate gland but not from the testicles. We concluded that routine fecal cultures at bull studs will reveal infected bulls before they become genitally infected and shed M paratuberculosis in semen.
Prevalence of Bovine Leukemia Virus Infection in Florida
Authors: Burridge M. J. , Puhr D. M. , Hennemann J. M.
Published: February 2025

A serologic study was undertaken to determine the prevalence of bovine leukemia virus (blv) infection in dairy and beef cattle in Florida. Using the agar gel immunodiffusion test with a glycoprotein antigen, 47.8% of 7,768 dairy cattle and 6.7% of 4,911 beef cattle were found to have antibodies to blv. The prevalence of blv antibodies increased significantly (P<0.0001) with increasing age. After data were adjusted for age, prevalence of blv antibodies was significantly associated with dairy breed (P<0.05) but not with species (Bos taurus and B indicus) or sex.
Risk Factors Related to the Prevalence of Infectious Bovine Keratoconjunctivitis
Authors: Webber Jonathan J. , Selby Lloyd A.
Published: February 2025

A cross-sectional epizootiologic study was conducted by mailed questionnaire to determine how the prevalence of infectious bovine keratoconjunctivitis (ibk) related to selected predisposing causes. The prevalence of ibk in Missouri during the summer of 1978 was 4.97 cases/100 cattle, with 45% of respondents reporting cases of ibk. A higher prevalence of ibk was associated with calves and yearlings, Hereford and Hereford-cross cattle, back-grounding cattle operations, and herds with a history of ibk. Vaccination of mature cattle against infectious bovine rhinotracheitis was associated with significantly higher prevalence of ibk in calves. A significantly lower prevalence of ibk was associated with dairy cattle operations, older cattle, and the winter months. There was no association between the prevalence of ibk and locale, nutrient supplementation, pasture management, use of vaccines other than infectious bovine rhinotracheitis, parasite prophylactic measures, or fly control measures.
Intraocular Granulomas Associated with Tuberculosis in Primates
Authors: West C. Sue , Vainisi Samuel J. , Vygantas Charles M. , Beluhan Frank Z.
Published: February 2025

Intraocular granulomas associated with tuberculosis were observed in 2 subhuman primates (Ateles geoffroyi and Macaca mulatta). Bacterial cultures from lung tissues at the time of necropsy confirmed the presence of Mycobacterium bovis and M tuberculosis, respectively. The absence of generalized clinical signs in spite of systemic dissemination of the organisms in these cases and the public health significance of tuberculous infections emphasize the importance of proper observation and diagnostic procedures in primate colonies and display collections.
Botulism in an Oregon Dairy Cow Herd
Authors: Gray Thomas C. , Bulgin Marie S.
Published: February 2025

Of 18 sick cows in a 100-cow dairy herd in Oregon, 14 died despite treatment. The cows were being fed high-moisture whole corn and alfalfa and rye haylage from pit silos. Signs of illness were anorexia, severe depression, and reduced milk production. Necropsy revealed only hyperemia of the abomasal mucosa and dilated, gas-filled large intestine. On the basis of response to treatment, laboratory findings, necropsy findings, and herd history, a tentative diagnosis of botulism was made. This diagnosis was confirmed by results of mouse inoculation tests. Injections of extract from the corn killed mice that were not protected by botulinum antitoxin.
Ataxia in four horses with equine infectious anemia
Authors: McClure Jill J. , Lindsay William A. , Taylor Wayne , Ochoa Ricardo , Issel Charles J. , Coulter Steve J.
Published: February 2025

In 4 horses with equine infectious anemia (eia), the predominant clinical sign was ataxia. Other clinical and laboratory findings often associated with eia included weight loss, anemia, pyrexia, thrombocytopenia, hemorrhages, hypergammaglobulinemia, and high activity of biliary epithelial enzymes. Neuropathologic findings were nonsuppurative granulomatous ependymitis, meningitis, and encephalomyelitis and plasmacytic-lymphocytic infiltration of the brain and spinal cord. The onset of neurologic signs corresponded to the acute stage of infection in at least 2 horses, and the signs developed at least 18 months after infection in 1 case. Cerebrospinal fluid from 3 of the horses contained high concentrations of protein and white cells, although changes in 1 horse may have been associated with a prior traumatic attempt to collect csf. By comparison, csf from 3 ponies inapparently infected with eia was normal. Active production of anti-eia antibody in the csf was suspected on the basis of serologic findings.
Effect of low carrier gas flows (50% oxygen/50% nitrous oxide) on inspired oxygen tension in anesthetized dogs
Authors: Haskins Steve C. , Knapp Robert G.
Published: February 2025

Low carrier gas flows of 50% oxygen/50% nitrous oxide were evaluated with regard to their effect on inspired oxygen (PIo2) and carbon dioxide (PIco2) tension during maintenance inhalational anesthesia in dogs, using a circle-system anesthetic machine. A total flow rate of 15 ml/min/kg was associated with a PIo2 of 230 ± 25 mm of Hg and a PIco2 of 0.4 ± 0.4 mm of Hg after 4 hours of methoxyflurane anesthesia. End-tidal carbon dioxide, minute volume ventilation, and ventilation frequency did not change during the 4 hours. Lower total flow rates were associated with collapse of the reservoir bag, or a PIo2<200 mm of Hg, or both.
Four types of occult Dirofilaria immitis infection in dogs
Authors: Rawlings C. A. , Dawe D. L. , McCall J. W. , Keith J. C. , Prestwood A. K.
Published: February 2025

Occult heartworm infection, ie, infection with adult Dirofilaria immitis in the absence of circulating microfilariae, was detected in dogs with prepatent infection, unisexual heartworm infection, drug-induced sterility of adult heartworms, and an immune-mediated infection. In the immune-mediated occult infection, female heartworms contained microfilariae that were antigenically similar to circulating microfilariae but were in a privileged site inasmuch as the intrauterine microfilariae were not coated with circulating antimicrofilarial immunoglobulin G. Transplantation of these female worms into heartworm-negative dogs resulted in microfilaremia.