bluuebunny/crossref_metadata_2025 huggingface dataset:
Caprine aflatoxicosis: Experimental disease and clinical pathologic changes
Authors: Clark J. Derrell , Hatch Roger C. , Miller Doris M. , Jain Anant V.
Published: February 2025

SUMMARY AND CONCLUSIONS

Groups of 8 male crossbreed domestic goats were given 3 dosage levels of aflatoxin B1[(afb1) mg/kg of body weight/day] orally: 0.1 for 34 days; 0.2 for 18 days; or 0.4 for 10 days. Clinical condition, feed consumption, and selected blood values were determined.

Clinical signs of toxicosis included decreased feed consumption, slight-to-moderate loss of body weight, mucopurulent nasal discharge, dyspnea, coughing, lethargy, icterus, diarrhea (4 goats), and subnormal body temperature 24 to 48 hours before death. Clinicopathologic changes included increases in total rbc count, pcv, hemoglobin concentration, serum bilirubin concentration, and serum activities of aspartate aminotransferase, isocitric dehydrogenase, and ornithine carbamyl transferase.

Goats given the 2 smaller dosage levels of afb1 had slight increases of serum total protein (tp) concentration compared with control goats, but goats given the larger dosage levels of afb1 initially had a slight decrease in tp. Aflatoxin had little effect on total wbc count. Serum alanine aminotransferase (alt) activities in goats given the 2 larger dosage levels of afb1 were similar to those of control goats, but goats given the smallest dosage level of afb1 had increased serum alt activities. Aflatoxin did not produce consistent dose-related changes in serum alkaline phosphatase activities.

Seemingly, goats are susceptible to aflatoxin. Onset of clinical signs was dose-related. Onset and magnitude of increases in pcv, hemoglobin concentration, serum bilirubin concentration, and activities of serum aspartate aminotransferase, ornithine carbamyl transferase, and isocitric dehydrogenase were dose-related. Changes in tp and activities of serum alt and alkaline phosphatase were neither dose-related nor were they potentially useful indicators of toxicosis.
Maturation of the retina of the canine neonate as determined by electroretinography and histology
Authors: Gum Glenwood G. , Gelatt Kirk N. , Samuelson Don A.
Published: February 2025

Retinal potentials were obtained by electroretinography from birth to maturity of dogs. Amplitudes, time latency, and flicker fusion frequencies under scotopic conditions were compared to the histologic development of the retina. There was no electroretinogram (erg) recorded during the 1st week of life, but in the 2nd week, a small negative wave (not exceeding 5 μV) was detected. Small erg waveforms appeared in dogs at 3 weeks of age; these markedly increased in amplitude and latency between the 3rd and the 4th weeks of age. Additional changes in the erg amplitudes were evident in the 5th to the 8th weeks of life approximating amplitudes of the adult dog. Similarly, the greatest changes in flicker fusion frequencies occurred between the 3rd and the 5th weeks and the 7th and the 8th weeks. Latency of the a-wave indicated little change in the age groups studied. The greatest decrease in latency occurred in the b- and c-waves between the 3rd and 5th weeks of age.

The rod and cone inner and outer segments were first observed microscopically in the 3rd week after the dogs were born. Further differentiation of the rod and cone segments and other retinal layers occurred from the 5th to the 8th weeks.
Strain differences in the susceptibility and resistance of Pasteurella multocida to phagocytosis and killing by rabbit polymorphonuclear neutrophils
Authors: Anderson Lynn C. , Rush Howard G. , Glorioso Joseph C.
Published: February 2025

The interactions of 2 capsular serotype A and 4 serotype D strains of Pasteurella multocida with rabbit polymorphonuclear neutrophils (pmn) were compared in vitro, using a pmn phagocytic and bactericidal assay. Bacteria and rabbit pmn were incubated for 15 minutes. The suspensions were subjected to differential centrifugation and the percentage of phagocytosis (cell association) was determined from the number of viable noncell-associated bacteria. The cell pellets and the associated bacteria were resuspended and pmn bactericidal activity was calculated from the number of remaining viable cell-associated bacteria at 45 and 75 minutes after the start of the assay. Test bacteria were not opsonized or were opsonized with immune serum containing active complement. One type A strain was ingested and killed by pmn in the presence and absence of opsonins. The 5 remaining strains were resistant to pmn killing, but only the type A strain resisted phagocytosis. Resistance of the type A strain was attributed to the hyaluronic acid capsule, since pretreatment of the bacteria with hyaluronidase rendered opsonized bacteria susceptible to ingestion and killing. The pattern of resistance of the 4 type D strains was different from that of the resistant type A strain. Both opsonized and nonopsonized type D bacteria became cell associated, but none were killed by pmn. The mechanism of resistance of these 4 strains to pmn bactericidal activity is currently unknown.
Antibody and complement-mediated cytotoxicity for bovine parainfluenza-3 virus-infected cells
Authors: Hussain A. , Mohanty S. B.
Published: February 2025

An antibody-complement-mediated cytotoxicity assay was employed to determine whether susceptible host cells infected with bovine parainfluenza-3 virus could be destroyed by the humoral immune mechanism. The cytotoxicity assay yielded 21.5% to 76.9% specific release of 51Cr with sera collected from calves 28 days after inoculation with the virus. A multiplicity of infection of 5, a postinfection period of 2 days, an antibody dilution of 1:10, and an incubation period of 12 hours with antibody and complement were found to be optimal for this assay.
Autotransplantation of bovine ocular squamous cell carcinoma and effects on primary tumor growth
Authors: Dennis Michael. W. , Kainer Robert A. , Lueker David C.
Published: February 2025

Autologous transplantation of ocular squamous cell carcinoma was done in 7 Hereford cows in 17 trials. Three preparations of tumor were used in orthotopic transplantation to 5 sites on the eye and eyelid. None of the transplants was successful. However, in 2 of 5 cows given autografts of a pure, viable tumor cell suspension, marked regression of the primary tumor was observed after transplantation.
Growth phase-dependent phagocytosis of Pasteurella haemolytica by bovine pulmonary macrophages
Authors: Walker R. D. , Schultz T. W. , Hopkins F. M. , Bryant M. J.
Published: February 2025

The ability of the bovine pulmonary macrophage (pm) to phagocytize Pasteurella haemolytica in its logarithmic and declining phases of growth was characterized. Pulmonary macrophages were harvested from bovine lungs before and after their in vivo exposure to P haemolytica. The pm from each lavage period phagocytized P haemolytica in the declining phase of growth. However, P haemolytica in the log phase of growth was not phagocytized by pm from any of the lavage periods. Instead, pm exposed to P haemolytica in the log phase of growth had altered cellular morphologic features and were cytolytic. Pasteurella haemolytica in the log phase also inhibited phagocytosis of Saccharomyces cerevisiae by pm. This inhibition of phagocytosis, as well as morphologic alterations, was evident in pm cultures exposed to P haemolytica for < 1 minute.
Toxocara antigen and mitogen-induced lymphocyte blastogenesis for diagnosis of visceral larva migrans: Clinical and experimental findings in macaques and human beings
Authors: Glickman Lawrence T. , Grieve Robert B. , DeGregory Karen T. , Friedman Henry S. , Stockman James A.
Published: February 2025

Peripheral lymphocytes from macaques inoculated with Toxocara canis and from children with serologically confirmed visceral larva migrans (vlm) were assayed for blastogenic responses using Toxocara antigen and standard mitogens. Macaques were given single or multiple larval infections. Lymphocyte responses of inoculated macaques were compared with responses from noninoculated macaques. Similarly, lymphocyte responses from 2 serologically confirmed human Toxocara vlm patients were compared with that of 2 healthy human controls. Mitogen responses of the macaques with multiple infections were higher than those with single infections or no infection, but these differences were not significant. Statistically greater (P < 0.05) Toxocara antigen-induced blastogenesis was observed for both groups of inoculated macaques and for each vlm patient. However, the degree of stimulation was low.
Relation of dietary carbohydrates to lipid metabolism and the status of zinc and chromium in rabbits
Authors: Moersen Thomas J. , Borgman Robert F.
Published: February 2025

Rabbits were fed a purified ration known to produce alterations in lipid metabolism and cholelithiasis. During a 14-week period, group 1 was fed sucrose as the sole dietary carbohydrate, whereas group 2 was fed corn starch; the rations were equicaloric and the carbohydrate provided 43% of the calories. Serum cholesterol and triglyceride concentrations increased when the purified rations were fed, and these concentrations were often greater (toward the end of the trial) in rabbits fed the sucrose than in rabbits fed corn starch. Liver weight was increased by the sucrose feeding, but there were no differences as to concentrations of lipid, cholesterol, Cr, or Zn between treatments. The aortas of the sucrose group contained more lipid, and the cholesterol concentrations tended to be greater; but dietary carbohydrate had no effect on concentrations of Cr or Zn. A reduction in hair Cr concentration was noticed over time in the rabbits fed sucrose, but changes were not noticed in the Zn concentrations. Cholelithiasis tended to be more severe in rabbits fed sucrose.
Clinical models for anaerobic bacterial infections in dogs and their use in testing the efficacy of clindamycin and lincomycin
Authors: Berg John N. , Scanlan Charles M. , Buening Gerald M. , Fales William H. , Schmidt Donald A. , Wilson J. C.
Published: February 2025

Two canine models of clinical anaerobic bacterial infections were developed for the study of the clinical parameters associated with these infections and for evaluation of antimicrobial agents that might be useful in therapy. In model I, a mixed culture of Bacteroides fragilis, B melaninogenicus, and Fusobacterium necrophorum was used as the inoculum. In model II, a mixed culture of B fragilis and Clostridium perfringens combined with an infection enhancer (sterile cinder dust) was used as the inoculum. In both models, reproducible localized pyogenic or gangrenous infections were induced. Clinical signs of fever, depression, and leukocytosis with a left shift were present. A depression in the nonspecific cell-mediated immune response was noticed.

The 2 models were used to evaluate clindamycin and lincomycin for therapy of anaerobic bacterial infections, using a subjective scoring system for severity of lesions and general clinical appearance. Clindamycin at dosage levels of 5.5 mg or 11 mg/kg of body weight, twice a day was highly efficacious in the treatment of anaerobic bacterial infections in both models. Dogs given lincomycin (22 mg/kg twice a day) responded to the treatment, but the response was less than that seen with clindamycin.
Transmission of bluetongue virus by intrauterine inoculation or insemination of virus-containing bovine semen
Authors: Bowen R. A. , Howard T. H.
Published: February 2025

Bluetongue virus was inoculated transcervically into the uterine body of estrous heifers to determine whether infection could be readily established by this route of exposure. Two strains of the virus were transmitted by intrauterine deposition.

Nine heifers were inseminated at estrus with 0.5 ml of processed, frozen-thawed semen that had been collected during the course of viremia in an experimentally infected bull. This semen contained titratable quantities of bluetongue virus. Of 9 inseminated heifers, 6 became pregnant and 3 became viremic and developed antibody to bluetongue virus. An additional heifer seroconverted, but did not become detectably viremic. Evidence of fetal infection was not present in the heifer that became infected and pregnant or in the 5 heifers that became pregnant, but were not infected.
Effect of procaine benzylpenicillin alone or in combination with dihydrostreptomycin on udder pathogens in vitro and in experimentally infected bovine udders
Authors: Franklin Anders , Holmberg Olof , Horn af Rantzien Margareta , Åström Goran
Published: February 2025

Minimum inhibitory concentration (mic) and minimum bactericidal concentration (mbc) of benzylpenicillin (pen) and dihydrostreptomycinsulfate (dhs) were determined for freshly isolated bovine udder pathogens. Killing curves were determined to study synergism of pen and dhs on Staphylococcus aureus and Streptococcus uberis. Healthy udder quarters of cows in their first lactation were inoculated with Str dysgalactiae or Str uberis strains. After development of acute mastitis, procaine pen alone or combined with dhs were given im, and the concentrations of pen and dhs in plasma and normal and mastitic milk were determined.

Twenty-four hours after 10 mg of procaine pen/kg of body weight (im), concentrations in mastitic milk equal to mic or mbc were maintained only for Str dysgalactiae. Twenty-four hours after 20 mg of procaine pen/kg (im), mbc in mastitic milk was maintained for Str uberis and 50% of the S aureus. When concentrations equal to mic or mbc of pen were combined with a sub-mic amount of dhs, the in vitro synergistic killing of Str uberis was not observed in vivo. In agreement with in vitro killing effect at pen concentrations equal to mbc, Str dysgalactiae was 100% eliminated in 5 cows when mbc of pen in mastitic milk was maintained for 24 to 36 hours. On the contrary, only 2 of 6 cows inoculated with Str uberis were free of this pathogen, although mbc of pen was maintained for 24 to 36 hours in mastitic milk.
Measurement of functional residual capacity and pulmonary carbon monoxide uptake in conscious Greyhounds
Authors: Amis T. C. , Jones Hazel A.
Published: February 2025

A simplified rebreathing method was developed for measurement of functional residual capacity (frc) and pulmonary diffusing capacity for CO in nonanesthetized standing Greyhounds. The frc was related to body weight according to the equation:

frc = 0.04 (body weight in kg)1.22

whereas pulmonary diffusing capacity for CO in nonanesthetized standing Greyhounds (ml/min/mm of Hg) = 2.34 (body weight in kg)0.66. The large frc per unit of body weight in the Greyhound emphasizes the need for breed specific prediction equations in veterinary respiratory physiologic studies and may reflect selection for exercise performance in the development of the Greyhound breed.
Antiviral responses of bluetongue virus-inoculated bovine fetuses and their dams
Authors: MacLachlan N. James , Schore Caroline E. , Osburn Bennie I.
Published: February 2025

Antiviral responses of bovine fetuses to bluetongue virus (btv) infection were determined. Fetuses inoculated with btv at 125 days of gestation apparently had cleared all virus by the time of birth; however, the mechanism responsible for virus clearance was not determined. Interferon production and virus clearance were temporally unrelated. Cell-mediated responses to btv antigens were not detected by the lymphocyte stimulation test using lymphocytes from infected fetuses or cows. Although virus clearance and fetal production of high titers of neutralizing antibody did coincide, it was considered unlikely that antibody alone was responsible for virus clearance. As congenital btv infection did not lead to specific immunologic tolerance or postnatal persistance of virus, such animals would not be expected to have a major role in the dissemination of btv.
Evaluation of fixation devices for prevention of rotation in transverse fractures of the canine femoral shaft: An in vitro study
Authors: Vasseur P. B. , Paul H. A. , Crumley L.
Published: February 2025

The effectiveness of various fixation techniques in preventing rotation of fracture segments in transverse fractures of the canine femoral diaphysis was evaluated under laboratory conditions. Single intramedullary Steinmann pins, single Küntscher nails, multiple intramedullary Steinmann pins, and an intramedullary Steinmann pin with a 1/2 Kirschner splint fixation sustained mean torque moments of 0.31, 0.61, 1.26, and 1.63 Newton meters, respectively, before rotation of the fracture segments occurred. Four-pin (full Kirschner) splints were more effective, sustaining a mean torque moment of 5.35 Newton meters before rotation occurred.

The canine femoral medullary canal had an average isthmus length of 2.0 to 2.5 cm. The restricted area of implant-cortex contact limited the effectiveness of the intramedullary fixation devices in preventing fracture segment rotation.
Intensification of milk somatic cell response to intramammary device
Authors: Paape Max J. , Corlett Norman J.
Published: February 2025

Treatments consisting of copper-impregnated polyethylene intramammary device (pimd-Cu), pimd-Cu which had been abraded to ensure exposure of surface copper (apbid-Cu), pimd which had been abraded in an identical manner (apimd), and an untreated control were established in mammary quarters of 2 cows. Quarters selected were bacteria free and had milk somatic cell counts (mscc) in strippings of < 240 × 103 ml. Milk somatic cell counts were determined from strippings immediately after milking and 6 hours later. Cows were monitored for 4 weeks after devices were inserted. Milk samples (250 ml) were collected and analyzed for free fatty acids, a measure of hydrolytic rancidity, at 14 days. The devices were removed from mammary quarters after 4 weeks and examined with a scanning electron microscope. Surfaces of the devices were assessed for plaque buildup and presence of leukocytes. Immediately after and 6 hours later, geometric mean mscc for apimd, apimd-Cu, pimd-Cu, and control quarters average 946/1,556, 1,479/2,882, 512/1,148, and 161/190 × 103 ml, respectively.

There was no difference in free fatty acid values of samples from treated and control quarters. Plaque formation was observed over the entire surface of apimd. Numerous leukocytes were found associated with plaque and appeared to initiate development of plaque. Smaller amounts of plaque were found on apimd-Cu, and minimal amounts were found on pimd-Cu. Results indicate that modification of pimd by abrading or addition of copper will increase msec to concentrations (> 900 × 103 ml) that should be protective against establishment of infection by mastitis pathogens.
Enzyme-linked immunosorbent assay for the detection of toxoplasmosis in swine: Interpreting assay results and comparing with other serologic tests
Authors: Waltman W. Douglas , Dreesen David W. , Prickett M. Dennis , Blue Jack L. , Oliver Diane G.
Published: February 2025

An enzyme-linked immunosorbent assay (elisa) was developed for the serodiagnosis of swine toxoplasmosis. The results of the elisa were interpreted as percentage (%elisa) and elisa titer and were compared with results of the dye test, indirect fluorescent antibody test, and indirect hemagglutination test, The results obtained from both the %elisa and elisa titer directly correlated with the dye test results. The elisa is a rapid, sensitive, and readily performed serologic test that should be ideal for examining (screening) swine for toxoplasmosis.
Halothane testing for malignant hyperthermia in swine: Dose-response effects
Authors: McGrath C. J. , Lee J. C. , Rempel W. E.
Published: February 2025

Purebred Pietrain malignant hyperthermia (mh)-susceptible pigs (n = 102) were subjected to halothane (0%, 1%, 2%, 3%, 4%, and 5%) in oxygen. The number of pigs in each group exhibiting muscle rigidity (mh(+) reaction) and the reaction times were recorded, as were the number of deaths resulting from mh.

Mortality was not affected by the halothane concentration. However, halothane concentration did markedly affect the number of mh(+) reactions and the reaction times. False-negative reactions were apparent in the pigs at halothane concentrations < 3%. Increasing the halothane concentration incrementally to 5% (from 0%) significantly (P < 0.05) decreased reaction times between treatment groups. The reductions in reaction times which occurred in the pigs given the 3%, 4%, and 5% halothane concentrations (62.1, 56.2, and 50.05)—although significant (P < 0.05)—would indicate that 3% halothane would generally be sufficient for mh testing.
Biochemical and serologic properties of Escherichia coli isolated from cows with acute mastitis
Authors: Sanchez-Carlo V. , Wilson R. A. , McDonald J.S. , Packer R. A.
Published: February 2025

Biochemical and serologic characteristics of 184 Escherichia coli isolates from cows with acute mastitis were determined. Trends or patterns unique to bovine isolates were not observed, except for the frequency of adonitol fermentation, which was positive in 84 (45.6%) of the cultures. Growth on Tergitol-7 agar had 3 types of colony morphologic characteristics; of these, the rough and intermediate textures predominated over those with smooth colony surfaces. A large variety of serovars was detected; the majority occurring as single isolates within a herd. Few K antigens were typeable. Only 2 isolates contained the K99 antigen. Seemingly, E coli organisms isolated from cows with acute mastitis cannot be distinguished as a specific pathogenic group on the basis of biochemical and serotest reactions.
Evaluation of bovine viral diarrhea virus uptake by preimplantation embryos
Authors: Potter M. L. , Corstvet R. E. , Looney C. R. , Fulton R. W. , Archbald L. F. , Godke R.A.
Published: February 2025

Bovine embryos were exposed to bovine viral diarrhea (bvd) virus in vitro. An uptake of bvd virus by the embryos could not be detected by several assay systems. A significant decrease in the titer of bvd virus was found to occur when the virus was incubated in saline solution + 5% goat serum or minimal essential medium + 5% goat serum for 24 hours at 37 C. Since there was significant inactivation of the bvd virus during the incubation period, lack of viral infectivity of the embryos may have been due to adverse effects of the experimental environmental conditions on the virus or the embryos or upon viral-embryo interaction.
Protection of chickens by ribosomal vaccines from Pasteurella multocida: Dependence on homologous lipopolysaccharide
Authors: Phillips M. , Rimler R. B.
Published: February 2025

Chickens were protected against fowl cholera by ribosomal vaccines prepared from noncapsulated Pasteurella multocida. Passive hemagglutination (pha) titers to lipopolysaccharide (lps) and the degree of protection conferred by ribosomal vaccines were diminished or abolished when ribosomes were chromatographed on an immunoadsorbent column. Addition of subimmunogenic amounts of serotype 1 (homologous) lps to highly purified ribosomes resulted in vaccines that protected against challenge exposure and produced pha titers to homologous lps. Addition of serotype 5 lps to highly purified ribosomes did not protect chickens against challenge exposure with serotype 1 P multocida, but produced pha titers to serotype 5 lps. Combinations of serotype 1 ribosomal RNA and serotype 1 (homologous) lps did not protect chickens or produce pha titers to lps.

Purified ribosomes from Brucella abortus, Aspergillus fumigatus, and chicken liver were combined with lps from P multocida and were evaluated as vaccines. Brucella abortus and A fumigatus ribosomes combined with lps protected chickens as well as did bacterin made from whole cells of P multocida. Chicken liver ribosomes combined with lps did not provide protection. To determine whether a protein carrier would substitute for ribosomes, methylated bovine albumin (mba) was combined with lps and evaluated as a vaccine. A serologic response to lps was induced by mba-lps vaccine, but the vaccine offered no better protection than when lps was used alone as vaccine. Ribosome-lps vaccines produced serologic responses to lps that were at least 5-fold greater than those produced by mba-lps vaccine.
Use of bacteria and yeasts to identify T lymphocytes in peripheral blood and lymphoid tissues of healthy guinea pigs and guinea pigs fed aflatoxin
Authors: McLoughlin Mary Ellen , Pier Allan C. , Thurston John R.
Published: February 2025

Fifty-four bacterial and 10 yeast isolates were screened to identify strains that were consistently bound by peripheral blood lymphocytes (pbl) of guinea pigs. None of the yeast isolates examined was bound by guinea pig pbl. Of 54 bacterial isolates, 10 were bound by > 5% of pbl. Potential lymphocyte markers from these bacteria were chosen for further study. Sodium azide inhibited the binding of bacteria by pbl.

Preparations of T lymphocytes indicated that Salmonella schottmuelleri was bound by most T lymphocytes; Yersinia enterocolitica was bound by a subpopulation of T lymphocytes. Patterns of binding of bacteria by lymphocytes from thymus, lymph node, or spleen differed from binding patterns obtained using pbl.

Aflatoxin did not affect the total wbc, differential leukocyte count, absolute lymphocyte count, or relative percentage of pcv of guinea pigs given as much as 0.060 mg of aflatoxin B1 equivalents/kg of body weight/day for 3 weeks. Changes in absolute numbers of peripheral blood T lymphocytes were not observed in guinea pigs given aflatoxin when immunofluorescence or bacterial binding was used to identify lymphocyte populations, except that the number of S schottmuelleri-binding lymphocytes (tentatively identified as T lymphocytes) in guinea pigs given the highest dose of aflatoxin (0.060 mg of aflatoxin B1 equivalents/kg/day) was less than the number of T lymphocytes identified by immunofluorescence.
Serum and cerebrospinal fluid concentrations of immunoglobulin G in Suffolk sheep with scrapie
Authors: Strain George M. , Barta Ota , Olcott Bruce M. , Braun William F.
Published: February 2025

Determinations were made by laser nephelometry of serum and csf immunoglobulin (Ig) G concentrations in Suffolk sheep with naturally occurring scrapie. The serum IgG concentrations in 3 sheep with confirmed or suspected scrapie were between 2,140 and 3,290 mg of IgG/100 ml, and the csf values were between < 10 and 75 mg of IgG/100 ml. In 8 clinically healthy (control) sheep, serum IgG concentrations were 2,647 to 7,380 mg/100 ml and csf IgG concentrations were between 0 (undetectable) and 162 mg/100 ml. A sheep with pulmonary adenomatosis had 1,445 mg of IgG/100 ml of serum. The results indicated that neither serum nor csf IgG concentrations were increased in sheep with naturally occurring infection with scrapie and that the severity of the disease did not correspond with the IgG concentration.
Immunogenicity and safety of an attenuated Bordetella bronchiseptica vaccine in pigs
Authors: Sakano Tetsuya , Sakurai Ken-ichiro , Furutani Takeshi , Shimizu Takeshi
Published: February 2025

The immunogenicity and safety of an attenuated Bordetella bronchiseptica vaccine for swine atrophic rhinitis (ar) was evaluated in 22 hysterectomy-produced, colostrum-deprived pigs and 18 conventional pigs.

None of 8 pigs inoculated at 7 days of age intranasally with ≥ 3 × 105 colony-forming units (cfu) of vacccinal strain/pig and 2 of 5 pigs inoculated at 7 days of age intranasally with 3 × 104 cfu of the vaccinal strain/pig developed ar after intranasal challenge exposure with a virulent strain at postinoculation week (piw) 3. The remaining 3 vaccinated pigs and 4 nonvaccinated pigs developed ar.

Thirteen pigs were inoculated intranasally with 3 × 106 to 3 × 109 cfu of the vaccinal strain at 7 days of age. At piw 12, the pigs were killed and necropsied. None of the pigs had clinical signs of ar and/or pneumonia.

Virulence was studied by transmission of vaccinal strain through 3 serial growing passages on the nasal mucosa of a litter of hysterectomy-produced colostrum-deprived pigs. inoculum (nasal swab samples from 2 pigs 4 days after inoculation with 108 cfu of vaccinal strain at 5 days of age) was inoculated into the nasal cavity of 2 nonvaccinated pigs. This procedure was repeated 3 times. After the 1st passage, the vaccinal strain was recovered on postinoculation day 4, but after postinoculation day 4, the vaccinal strain was not recovered until the end of the 3rd passage. Turbinate atrophy or pneumonia was not recognized in these inoculated pigs.

The vaccinal strain provided immunogenicity without ill effects.
Effectiveness of various therapeutic regimens for bovine brucellosis
Authors: Milward Francis W. , Nicoletti Paul , Hoffmann Edward
Published: February 2025

Various chemotherapeutic regimens were evaluated in 48 culture-positive dairy cows. Cessation of shedding of Brucella abortus from udder secretions and absence in selected tissues at necropsy were criteria of success.

A combination of a long-acting oxytetracycline and streptomycin eliminated Brucella in 10 of 14 (71.4%) cows. Two cows that were retreated with the same regimen also became culture-negative. Other treatment regimens, including the use of liposome-encapsulated antibiotics, were less successful.

Serotests were a poor criterion of effectiveness.
Metabolic responses to fasting and alloxan-induced diabetes mellitus in steers
Authors: Smith Stephen B. , Prior Ronald L.
Published: February 2025

To induce diabetes mellitus in 8 steers, they were fasted for 96 hours and given 110 mg of alloxan/kg of body weight (iv, in 1 dose) immediately before refeeding. Subsequently, 4 of the steers were treated with insulin (0.1 to 3 U/kg) to control hyperglycemia and 4 were not given insulin. Four control steers were fasted and refed. Fasting increased serum phosphorus, total protein, and bilirubin and decreased serum magnesium and potassium. Refeeding returned serum values of magnesium, potassium, total protein, and bilirubin toward base-line values, regardless of treatment group. However, serum phosphorus remained increased in steers with alloxan-induced diabetes and was not lowered by insulin injections. Sodium and chloride values were depressed in steers with alloxan-induced diabetes; these values remained significantly (P < 0.05) lower than base-line values, even in steers given insulin. Fat infiltration was evident in the pancreas, liver, and to some extent, kidneys of steers with alloxan-induced diabetes, but was occasionally present in tissues of steers given insulin.
Effect of dietary niacin supplementation on serum constituents of periparturient dairy cattle
Authors: Dufva G. S. , Bartley E. E. , Nagaraja T. G. , Dayton A. D. , Frey R. A.
Published: February 2025

A total of 60 multiparous periparturient Holstein cows were used to determine the differences in serum constituents between cows given supplemental niacin in the diet and cows not given supplemental niacin. Serum inorganic phosphorus concentration was consistently higher (P < 0.10) and serum potassium, total calcium, and sodium concentrations and alkaline phosphatase activities were consistently lower in cows given supplemental niacin than in cows not given supplemental niacin. Serum chloride, creatinine, and albumin values also tended to be lower in niacin-supplemented cows. Serum total protein tended to be slightly higher in niacin-supplemented cows. There was no consistent difference in urea nitrogen between groups of cows.
Function of prostaglandins, thromboxane A2, and histamine in hypersensitivity reaction to experimental bluetongue disease in calves
Authors: Emau Peter , Giri S. N. , Anderson G. A. , Stott J. L. , Osburn B. I.
Published: February 2025

Calves given 2 subcutaneous inoculations (4 ml, 4.5 weeks apart) of an inactivated bluetongue virus serotype 17 (btv-17), aluminum hydroxide adjuvant, and cimetidine (600 mg) or levamisole (819 mg, 6 ml) combination were challenge exposed with virulent btv-17 (2.5 × 105 embryo lethal dose) 9 weeks after the 1st inoculation and were monitored for 35 days. Plasma prostaglandins (pg) and thromboxane (Tx) B2 were measured by radioimmunoassay. Histamine was assayed spectrofluo-rometrically. During the inoculation period (9 weeks from the 1st inoculation to challenge exposure) pge and histamine increased from base-line concentrations of 34 ± 3 pg/ml and 1.2 ± 0.1 ng/ml to 83 + 8 pg/ml and 2.0 ± 0.1 ng/ml, respectively, whereas PGP2α decreased from baseline values of 356 ± 41 pg/ml to 226 ± 16 pg/ml. Significant (P ≤ 0.05) changes from base-line TxB2 values (110 ± 7 pg/ml) were not observed during the inoculation period. After challenge exposure, maximum increases were observed in TxB2 (157 ± 10 pg/ml), pgf2α (713 + 93 pg/ml), pge (140 ± 30 pg/ml), and histamine (3.6 ± 0.2 ng/ml) concentrations at 4, 7, 7, and 14 days after challenge exposure, respectively. Concentrations of pgf2α and TxB2 decreased from base-line values to 211 ± 42 pg/ml and 75 ± 11 pg/ml, respectively, 21 days after challenge exposure and then returned to base-line values. Significant changes were not observed in plasma concentrations of 6-keto-pgf1α. Results indicate that pg, TxA2, and histamine may be involved in the hypersensitivity reaction to btv in cattle.
Vaccination of calves against Salmonella dublin with aromatic-dependent Salmonella typhimurium
Authors: Smith Bradford P. , Reina-Guerra Mario , Stocker Bruce A. D. , Hoiseth Susan K. , Johnson Eugene H.
Published: February 2025

Ten Holstein calves were divided into 2 groups. Five calves served as nonvaccinated controls, and 5 calves were vaccinated im at 2 and 3 weeks of age with 109 aromatic-dependent (aro- ) Salmonella typhimurium strain SL1479 containing 0 antigens 1, 4, 12. Serious adverse reactions to vaccination were not observed in the calves. Mean maximum rectal temperature increase in the vaccinated calves was 1.5 C. One calf had diarrhea and depressed appetite for 1 day after vaccination. At 5 weeks of age, all calves were challenge exposed orally with 1.5 × 1011 virulent S dublin strain SL1367 (O antigens 9,12). After challenge-exposure inoculum was given, 1 of 5 vaccinated calves died and 4 of the 5 nonvaccinated calves died (P < 0.05). Thus, some cross serotype protection against S dublin was induced by parenteral vaccination of calves with aro- S typhimurium strain SL1479, although protection was not complete.
Evaluation of field isolates of pseudorabies (Aujeszky's disease) virus as determined by restriction endonuclease analysis and hybridization
Authors: Pirtle E. C. , Wathen M. W. , Paul P. S. , Mengeling W. L. , Sacks J. M.
Published: February 2025

Sixty-seven isolates of pseudorabies virus (prv) from 13 states were cleaved with 4 restriction endonucleases (re), and after electrophoresis in agarose, their banding patterns were photographed and evaluated. The deoxyribonucleic acid (dna) cleavage fragments were designated into regions specified by molecular weight ranges based on lambda phage dna as a size marker. The 67 prv isolates were evaluated according to the total number of cleavage fragments, by the number of fragments within designated molecular weight regions, and finally, by the migration of fragments within regions. Four ofthe 67 prv isolates (all 4 from California) did not have a 4.1 to 4.6 megadalton HinfI band, but hybridization of the HinfI digests with a 32P probe made with the 4.4 megadalton band hybridized with 2 lighter fragments, 2.5 and 1.9 megadaltons, respectively. The BamHI digests of dna from some prv isolates with submolar fragments were hybridized with 32P probes made with fragments from the submolar region and the BamHI E fragment. Both probes hybridized to the submolar region of prv with BamHI submolar fragments, but only to the trimolar (E, F, and G) band of prv without submolar fragments in the 4.1 to 7.5 BamHI megadalton region. Epidemiologic evidence was obtained which indicated that a Missouri strain of prv was transferred to an Illinois swine herd by importation of feeder pigs from Missouri. The results indicate that there are numerous genomically different prv currently in circulation in the United States and that the combination of re analysis and dna hybridization offers useful epidemiologic information to evaluate the various strains.
Immune response of swine vaccinated with a group E Streptococcus whole-culture bacterin
Authors: Wood R. L. , Wessman G. E.
Published: February 2025

Swine (n = 10) were given a concentrated whole-culture adsorbate bacterin made from group E Streptococcus (ges). Two doses of bacterin were given subcutaneously 3 weeks apart. Control swine (n = 10) were given a blank preparation made from sterile culture medium. Swine were challenge exposed 3 weeks after the 2nd injection of bacterin by being penned continuously for 8 weeks with carrier swine infected with ges. A significant (P ≤ 0.009) immune response to vaccination with the bacterin was observed. Vaccinated swine, but not control swine, developed antibodies to an antiphagocytic factor (as detected with bactericidal and long-chain tests) before challenge exposure. Vaccinated swine also developed 51.2% (20 vs 41) fewer abscesses after challenge exposure than did control swine. Control swine developed a greater serologic response to challenge exposure, indicating a more extensive infection with ges.
Plasma mepivacaine concentrations after caudal epidural and subarachnoid injection in the horse: Comparative study
Authors: Skarda R. T. , Muir W. W. , Ibrahim A. I.
Published: February 2025

The venous plasma concentrations of mepivacaine were determined in 7 adult mares (420 ± 17.1 kg) given an injection of a 2% solution of the hydrochloride at either the sacral (S2-3 to S5-C1) epidural space or the midsacral (S2-3) subarachnoid space. An average dose of 91.4 ± 15.7 mg (4.6 ± 0.8 ml) was needed to produce caudal epidural analgesia (cea) and 26.7 ± 5.4 mg (1.3 ± 0.3 ml) to produce caudal subarachnoid analgesia (csa).

Maximal caudal analgesia extended from spinal cord segments S-l to coccyx during cea and csa. The onset of analgesia as measured by response to superficial and deep muscular pinprick stimulations was significantly (P < 0.05) faster in mares with csa than with cea (8.3 ± 2,4 minutes vs 21.4 ± 3.8 minutes). The period of analgesia was significantly (P < 0.05) longer in mares with cea than with csa (80.0 ± 11.5 minutes vs 67.4 ± 26.3 minutes).

The rate of vascular absorption of mepivacaine from the epidural space was significantly (P < 0.05) faster than from the subarachnoid space. Maximum venous plasma concentrations of mepivacaine were similar (P > 0.05) after epidural and subarachnoid injections (0.05 ± 0.03 μg/ml and 0.05 ± 0.03 μg/ml) at the same times after mepivacaine administration (51.4 ± 33.4 minutes and 53.6 ± 24.3 minutes). Mean venous plasma concentrations of mepivacaine at 60 and 75 minutes were significantly higher after epidural than subarachnoid injection (0.04 ± 0.03 μg/ml vs 0.02 ± 0.03 μg/ml and 0,03 ± 0.02 μg/ml vs 0.02 ± 0.02 μg/ml). Mean plasma concentrations of mepivacaine at the cessation of analgesia were not significantly different (P > 0.05) after epidural and subarachnoid injections (0.03 ± 0.02 μg/ml vs 0.02 ± 0.02 μg/ml). The venous plasma concentrations of mepivacaine determined during cea and csa did not produce measurable direct systemic effects on the cardiovascular system of conscious mares.
Healing of experimentally induced wounds of mammary papilla (teat) of the cow: Comparison of closure with tissue adhesive versus nonsutured wounds
Authors: Grymer Jorgen , Watson Gary L. , Coy Charles H. , Prindle Lynn V
Published: February 2025

Lacerations were surgically produced on the mammary papillae (teats) in 11 healthy dairy cows (10 Holstein and 1 Guernsey), Chemical restraint and local anesthesia were used before the lacerations were done. Twenty-one lacerations (10 front and 11 rear papillae) were apposed with synthetic adhesives, Eight lacerated papillae (6 front and 2 rear) were allowed to heal without tissue apposition. Healing was evaluated daily by palpation and visual inspection, Histologic and subgross photomyorographies were done at the time of slaughter (13 to 20 days).

Of the 21 lacerated wounds apposed with adhesive materials, 17 healed by primary intention (81%). One papillary laceration dehisced on the second day and developed a milk fistula. The remaining 3 wounds which were initially repaired with adhesives were injured during the cows' anesthetic recovery and were reapposed with adhesives. The latter healed, but not as well as did the 17, Clinically, there was no detectable differences between adhesives as concerns healing.

Of the 8 controls (papillary lacerations that were not apposed), 3 healed by 1st intention (37.5%), The remaining five (62.6%) healed by 2nd or 3rd intention with fistula formation.

When evaluated by subgross photomycrography, 20 wounds (18 glued; 2 controls) were bridged by connective tissue and showed no change in wall thickness. Three papillary lacerations (2 glued; 1 control) showed different stages of bridging with connective tissue and wall thickness.

Histopathologic evaluation revealed a marked foreign body response evidenced by giant cell and epithelial macrophages adjacent to all lacerations apposed with adhesives. Tissue alteration varied widely depending on the method of tissue apposition and the tissue adhesive used.
Auditory-evoked response in the clinically normal dog: Middle latency components
Authors: Sims Michael H. , Moore Robert E.
Published: February 2025

The middle latency components (6 to 60 ms) of the auditory-evoked response were recorded in clinically normal mature dogs (n = 15 mixed breed). To record the middle latency response (mlr), a series of suprathreshold auditory clicks was presented monaurally to nonanesthetized and anesthetized dogs at a stimulus rate of 5/s. To determine effects of stimulus intensity on wave amplitude and latency in nonanesthetized dogs, clicks were presented at 90-, 70-, and 50-dB hearing level. Filtered electroencephalic activity during the first 100 ms after each click was recorded and averaged digitally for 1,024 consecutive stimuli. The response pattern in the nonanesthetized dog was a repeatable polyphasic configuration characterized by 3 to 4 major waves. Peaks of the waves were labeled, using a method developed in human beings. Mean latency ranges for the positive (P) or negative (N) peaks that comprised the waves across intensity levels were 7.43 to 7.77 ms (No), 11.07 to 11.57 ms (Po), 13.62 to 14.20 ms (Na), 20.04 to 20.68 (Pa), 39.08 to 39.37 ms (Nb), and 54.25 to 55.21 ms (Pb). The only variations in waveform morphologic features were the additional wave formed by peaks Nx (24.80 to 25.94 ms) and Px (30.0 to 30.62 ms), which occurred in 44% of the records, and the missing wave formed by No and Po in 6.6% of the records.

Varying the stimulus intensity had no effect (P > 0.05) on wave amplitude or latency. However, anesthesia with 20 mg of thiamylal sodium/kg of body weight virtually eliminated the mlr evoked by the 90-dB stimulus, thus indicating higher brain centers as possible neural generators. The latency and waveform stability of the mlr in nonanesthetized dogs underscore its potential as an additional and reliable index for audiologic, otologic, and neurologic testing.
Immunoradiometric assay for quantitation of Dirofilaria immitis antigen in dogs with heartworm infections
Authors: Hamilton Robert G. , Scott Alan L.
Published: February 2025

An immunoradiometric assay (irma) was developed, optimized, and validated for detection of parasite-specific antigen in sera from hosts with filarial infections, using Dirofilaria immitis in dogs as a model. The precision, reproducibility, and parallelism of the irma were examined, using precision profile analysis. The irma had acceptable precision and reproducibility [< 15% intra-assay coefficient of variation (cv)] over a working range of 10 to 2,000 ng of D immitis-antigen (ag)/ml. The irma parallelism (agreement between dilutions) was acceptable (< 10% interdilutional cv) with laboratory-spiked D immitis ag sera containing no D immitis-antibody (ab). However, it was not acceptable (> 20% interdilutional cv) for analysis of sera from naturally infected dogs containing D immitis ab, probably due to dissociation of immune-complexed ag with increasing serum dilution. Nonparallelism limited the accuracy of binding data interpolation from the standard curve. Specificity of the irma was enhanced by preabsorption of the radiolabeled detection antibody with Toxocara canis ag before use. Varying amounts of D immitis ag (22 to 1,000 ng/ml) were detected in 42% (20/48) of microfilaremia dogs. The presence of ag-specific ab at concentrations as low as 1 μg/ml reduced the ability of the irma to detect D immitis ag. Factors that influence the accuracy and sensitivity of immunoassays for circulating filarial antigens are discussed.
Effect of a range of social stress severity on Escherichia coli challenge infection
Authors: Gross W. B.
Published: February 2025

Chickens were exposed to various degrees of social stress 1 day before being exposed to Escherichia coli air-sac challenge exposure. Increasing levels of social stress resulted in increased heterophil/lymphocyte (h/l) ratios. Resistance to E coli air-sac challenge infection increased in correspondence with h/l ratios. However, as h/l ratios increased above the 0.72 value, there was a corresponding decrease in resistance to E coli challenge infection. Changes in h/l ratios, in response to social environment, differed with genetic stocks. Social stress was greatest when chickens housed singly for 3 weeks were placed among 5 unfamiliar chickens.
Prevalence of antibodies to porcine adenovirus in swine by indirect fluorescent antibody test
Authors: Dea S. , El Azhary M. A. S. Y.
Published: February 2025

An indirect fluorescent antibody test was developed for routine identification of a porcine adenovirus and its specific antibody. Two specific-pathogen-free young pigs were inoculated with the viral antigen prepared in continuous porcine kidney cell cultures, and their sera were used as an antibody reagent to standardize the test. Sera of adult pigs with respiratory problems, obtained from pig farms in Quebec, were tested for antibodies to this virus; 83 of 540 sera tested (15.2%) were found to be positive.
Antigen beads: A novel approach for the delivery of a soluble Anaplasma immunogen
Authors: James Mark A. , Coronado Alfredo , Melendez Roy D. , Ristic Miodrag
Published: February 2025

An important consideration in the development of effective immunization regimens against bovine anaplasmosis is the optimization of vaccine delivery systems. This report describes the formulation of proteinaceous antigen-containing spheres derived from supernatant fluids of Anaplasma marginale cultures. The antigen beads were designed for use as potential dispersal agents for a soluble Anaplasma immunogen. Immunospecificity assays demonstrated that A marginale antigen was located on the surfaces of individual antigen beads. Use of Anaplasma antigen beads with a potent adjuvant, such as saponin, was proposed.
Differentiation of cytopathic and noncytopathic isolates of bovine viral diarrhea virus by virus neutralization
Authors: Coria M. F. , Schmerr M. J. F. , McClurkin A. W. , Bolin S. R.
Published: February 2025

Soluble antigens of cytopathic and noncytopathic isolates of bovine viral diarrhea virus were resolved by high-performance liquid gel-permeation chromatography into 4 major and 3 minor peaks. The 2 peaks with the larger molecular weights (240,000 and 140,000 daltons) were immunogenic when inoculated into rabbits. Virus neutralizing antibodies were specific for the homologous virus. The soluble antigens were determined to be > 100,000 daltons by filtration.