bluuebunny/crossref_metadata_2025 huggingface dataset:
Cortical somatosensory evoked potentials in cows
Authors: Strain George M. , Kraus-Hansen Ann E. , Tedford Bruce L. , Claxton-Gill Marjorie S.
Published: January 2024

A method was developed to record cortical somatosensory evoked potentials (sep) from thoracic and pelvic limb stimulation in cows. Recordings were similar in latency and amplitude to those reported for horses. Correction for conduction pathway length did not alter the average latency values because the cows of the study were uniform in size; however, the data provided will enable use of this normative data with smaller or larger individual animals.

Although latency variability for the sep peaks was low, variability of the amplitude measurements was high. This observed variability was similar to that seen in other species. Validity of the recorded responses was indicated by lack of a tibial nerve sep in 1 cow that had been given a tibial nerve conduction block, using lidocaine, and by repeatability of the response in 2 recordings taken 1 year apart in the same cow.
Histochemical and morphologic changes of porcine airway epithelial cells in response to infection with Mycoplasma hyopneumoniae
Authors: DeBey Mary C. , Jacobson Carol D. , Ross Richard F.
Published: January 2024

Mycoplasma hyopneumoniae causes pneumonia in pigs. The effect of infection by this organism on histochemical characteristics of airway mucin within epithelial cells was studied. Seven- to 10-week-old pigs were inoculated intratracheally with M hyopneumoniae or culture broth, and lung tissues were collected from inoculated and control pigs at 2, 4, and 6 weeks after inoculation. Tissue sections were stained with periodic acid-Schiff/Alcian blue, pH 2.5 or high iron diamine/Alcian blue. Histologic features of randomly selected bronchi, bronchioles, and submucosal glands were compared in sections stained with periodic acid-Schiff/Alcian blue. Bronchial goblet cell sulfomucin and sialomucin were quantitated by image analysis of sections stained with high iron diamine/Alcian blue. Bronchi and bronchioles of infected pigs contained proportionately fewer goblet cells with mucin at all stages of infection than age-matched control pigs. Goblet cells in bronchi of infected pigs contained significantly less total mucin and sialomucin, and significantly more sulfomucin than goblet cells of control pigs. Increased sulfated mucin in bronchial goblet cells may reflect altered glycoprotein production or secretion in response to infection with M hyopneumoniae.
Single-step technique for staining Anaplasma marginale in bovine blood smears
Authors: Hart L. T. , Morris N. G. , Bessin R. , LePrince D. J. , Todd W. J. , Enright F. M. , Luther D. G.
Published: January 2024

Three available differential stains, Camco-Quik, Diff-Quik, and Wright-Giesma were compared for detection of intraerythrocytic Anaplasma marginale in bovine blood smears. In samples where < 1% to more than 51% of the rbc were infected, statistical analysis of the data indicated no significant difference in the detection of A marginale with Camco-Quik or Diff-Quik stains. However, a significantly lower percentage of infected rbc were detected when blood smears were stained with the Wright-Giemsa stain, compared with the other 2 methods.
Determination of protein concentrations and their molecular weight in tears from cats with normal corneas and cats with corneal sequestrum
Authors: Davidson Harriet J. , Gerlach John A. , Bull Robert W.
Published: January 2024

Protein concentration was determined, using the Bradford technique, in tears from cats with normal corneas and from cats with corneal sequestrum. Tears from the former group contained 5.81 ± 2.29 mg of protein/ml; those from corneal sequestrum-affected cats contained 6.21 ± 2.21 mg/ml. Difference between the 2 values was not significant. Molecular weight determination was made, using 4 to 20% sodium dodecyl sulfate-polyacrylamide gels. Molecular mass of proteins ranged from 263 to 14 kDa. There was no detectable difference in the band patterns for the 2 groups.
Evaluation of an automated system for hemoglobin measurement in animals
Authors: Callan Mary Beth , Giger Urs , Oakley Donna A. , Scotti Mary V. , Shofer Frances S.
Published: January 2024

In veterinary medicine, pcv determined by centrifugation of blood in a microhematocrit tube is the most common clinical test used to initially assess and monitor anemic and polycythemic animals. In contrast, blood hemoglobin (Hb) concentration, rather than pcv, is generally determined in human patients. One automated system photometrically measures blood Hb concentration after conversion of Hb to azide methemoglobin without dilution and was found to be a simple and accurate instrument for use in human medicine. We evaluated the system for its accuracy in measuring blood Hb concentration in animals by comparing it with standard techniques and for its suitability in veterinary practice. Blood samples, anticoagulated with potassium edta, from 78 healthy animals (33 dogs, 17 cats, 13 horses, and 15 cows) and 58 dogs and 4 cats with various blood abnormalities (10 anemia, 11 polycythemia, 21 lipemia, 16 leukocytosis, and 6 icterus) were analyzed. In all species, blood Hb concentration of healthy animals determined by the system was comparable to that measured by standard cyanmethemoglobin methods (ie, an automated counter; rI = 0.987 to 0.998 and a hemoglobin kit, rI = 0.946 to 0.993). The aforementioned system also yielded similar values to those obtained by use of standard methods in anemic, polycythemic and icteric dogs and cats. Moreover, the system reads the absorbance at 2 wavelengths to correct for turbidity, and therefore, accurately measured Hb concentration in blood samples with severe lipemia (triglycerides concentration > 500 mg/dl) and marked leukocytosis (> 50,000 wbc/μl, whereas other standard Hb techniques are known to give falsely high results. We conclude that the automated system compares favorably to standard methods, and is a simple and accurate instrument to quickly measure Hb concentration in animals.
Arteriovenous differences for glutamine in the equine gastrointestinal tract
Authors: Duckworth Donna H. , Madison John B. , Calderwood-Mays Maron , Souba Wiley W.
Published: January 2024

Glutamine has been shown to be an important metabolic substrate of enterocytes in many animals, including cats, dogs, hamsters, human beings, monkeys, rabbits, rats, and sheep. To determine whether glutamine is important in the metabolism of cells of the equine gastrointestinal tract, we examined transintestinal differences in glutamine concentrations in the arterial and venous circulation, and measured activity of the major glutamine catabolizing enzyme, glutaminase. Arteriovenous differences provide an index of the amount of a given substrate removed by the tissue across which the measurements are made, and commonly are expressed as a percentage of substrate removed, or percent extraction. Arteriovenous differences for glutamine were determined in 7 anesthetized adult horses (weight, 450 to 500 kg) before and after an iv glutamine infusion. The mean baseline arterial glutamine concentration (± sem) was 572 ± 24 μM; this concentration quadrupled (to 2,167 ± 135 μM, P < 0.01) 1 minute after iv bolus infusion of a 17.5-g glutamine load. Baseline extraction by the portal-drained viscera was 7.5 ± 1.5%; this value increased to 18 ± 2% at 1 minute (P < 0.01) and had returned to baseline values 60 minutes later. Arteriovenous differences were greatest across the jejunum (11.8 ± 1.8% in the baseline period vs 33.1 ± 3.1% at 1 minute, P < 0.001), with smaller differences across the colon, suggesting that the jejunum was the more avid utilizer of glutamine. Glutaminase activity was 4.38 ± 0.16 and 4.00 ± 0.60 μmol/mg of protein/h under standard conditions in jejunal and ileal mucosa, respectively. Kinetic studies of jejunal glutaminase revealed the enzyme to have a Km of 3.81 ± 0.35 mM and a Vmax of 8.08 ± 0.54 μmol/mg of protein/h, suggesting that the small intestine of horses has a high capacity to extract and metabolize circulating glutamine.
Retrospective evaluation of factors associated with the risk of seropositivity to Ehrlichia risticii in horses in New York state
Authors: Atwill Edward R. , Mohammed Hussni O. , Dubovi E. , Lopez J.
Published: January 2024

A retrospective study was designed to determine the distribution of equine monocytic ehrlichiosis among the equine population in New York state, and to identify factors associated with risk of disease. Serum samples submitted to the diagnostic laboratory of the university during the period from January 1985 through December 1986 were examined for antibodies to Ehrlichia risticii, using the indirect fluorescent antibody technique. Factors evaluated included geographic origin and date of submission of the sample, and age, breed, and sex of the horse. Logistic regression analysis was used to identify which factors were significantly associated with the risk of seropositivity to E risticii, while simultaneously controlling for other factors.

Of the 2,579 tested samples, 1,950 (76%) had positive results. Factors significantly associated with risk of seropositivity to E risticii were: breed of the horse (Thoroughbreds were 3 times more likely to have been exposed to E risticii, compared with non-Standardbred, non-Thoroughbred breeds); sex (female horses were 2.7 times more likely to have been exposed, compared with male horses); age of the horse (the risk of being exposed to E risticii increased with age, peaked at around 12 years, and decreased thereafter); and month of submission (horses tested during November and December had the highest odds of being seropositive [odds ratio = 2.1], and horses tested during March through April were least likely to be seropositive [odds ratio = 0.5], compared with horses tested during January and February).
Role of memory B-cell responses in serum and mucosal fluids of swine for protective immunity against pseudorabies virus
Authors: Kimman T. G. , Oei-Lie N. , van Zaane D.
Published: January 2024

We examined primary and memory isotype-specific antibody responses directed against pseudorabies virus in serum and mucosal fluids of pigs with and without passively acquired maternal antibody, and we studied the relationship between these responses and protection against virus challenge. Pigs were inoculated intranasally with the virulent NIA-3 strain or the avirulent Bartha strain, or they were inoculated im with an inactivated vaccine containing the Phylaxia strain. Ten weeks later, all pigs were challenge-exposed intranasally with strain NIA-3. Only pigs that were without passively acquired antibody at the time they were inoculated with virulent virus appeared to have complete protective immunity against challenge exposure, as evidenced by lack of clinical signs of pseudorabies and lack of virus excretion. In contrast, pigs inoculated with strain Bartha or with the inactivated vaccine developed fever, had a period of growth arrest, and excreted virus after challenge exposure. In pigs without passively acquired antibody, intranasal inoculation with strains NIA-3 or Bartha was followed by primary IgM and IgA responses in serum and in oropharyngeal fluid as well as primary IgG1 and IgG2 responses in serum. Intramuscular inoculation with the inactivated vaccine induced primary serum IgM, IgG1, and IgG2 responses, but no mucosal responses. Challenge exposure of pigs that had been inoculated with the Bartha strain or the inactivated vaccine was followed by clear memory responses in serum and in oropharyngeal fluid. In contrast, challenge exposure of pigs that had been inoculated by the virulent NIA-3 strain was not followed by memory responses. Passively acquired antibody decreased primary and memory responses in serum and in mucosal fluids and the induction of protective immunity. Thus, systemic and mucosal B-cell memory responses in vaccinated pigs were unable to prevent virus multiplication. In contrast, in pigs inoculated with virulent virus, challenge exposure failed to stimulate a secondary antibody response in memory B cells. This may have been attributable to inadequate stimulation of memory B cells as a consequence of early elimination of infected cells by T cells.
Evaluation of two test procedures for diagnosis of giardiasis in dogs
Authors: Barr Stephen C. , Bowman Dwight D. , Erb Hollis N.
Published: January 2024

Two commercially available tests, an antigen-capture elisa for use on fecal samples, and a peroral nylon string test for use in dogs, were compared with a zinc sulfate fecal concentration technique (zsct) for detection of giardiasis in dogs. Of 77 dogs and 164 fecal samples (from these dogs), 33 and 52, respectively were found to be Giardia-positive on the basis of results of the zsct. The elisa gave false-negative results for 10 and 14% of zsct-positive dogs and fecal samples, respectively, and false-positive results (relative to the zsct test results) in 13 and 10% of zsct-positive dogs and fecal samples, respectively.

Of the 18 string-tested dogs, 14 were positive by results of the zsct. Of the 4 dogs that were Giardia-negative by zsct, 2 were Giardia-positive by elisa. Dogs were sedated and given water and metoclopramide to aid passage into the duodenum of the capsule containing a nylon string. Of the 21 string tests performed on the 18 dogs, only 5 strings reached the duodenum, and 0 of the 5 yielded positive results for Giardia sp. Because the string broke in 1 dog (leaving most in the gastrointestinal tract and, therefore, producing a risk of string foreign body) further string tests were not done.
Ultrasonographic appearance of the uterus, placenta, fetus, and fetal membranes throughout accurately timed pregnancy in Beagles
Authors: Yeager Amy E. , Mohammed Hussni O. , Meyers-Wallen Vicki , Vannerson Leslie , Concannon Patrick W.
Published: January 2024

Serial ultrasonographic examinations were performed on 8 Beagle bitches from 20 to 60 days pregnant to determine time of first detection, appearance, and sizes of selected features of pregnancy. Gestation was timed from the day of the preovulatory luteinizing hormone surge. Findings related to gestational age were consistent among bitches.

Gestational ages at earliest detection of the following features were: chorionic cavity at day 20; placental layers in the uterine wall at day 22 to 24; zonary placenta at day 27 to 30; embryo and heartbeat at day 23 to 25; yolk sac membrane at day 25 to 28; allantoic membrane at day 27 to 31; choroid plexus of the brain at day 31 to 35; fetal movement at day 34 to 36; skeleton at day 33 to 39; bladder and stomach at day 35 to 39; kidney at day 39 to 47; and liver hypoechoic, compared with lung, at day 38 to 42.

Extra-fetal structures were measurable from day 20 or 22 through day 48. Chorionic cavity diameter increased from 0.2 ± 0.0 cm to 3.3 ± 0.2 cm, outer uterine diameter increased from 0.8 ± 0.03 cm to 4.8 ± 0.2 cm, length of chorionic cavity or zonary placenta increased from 0.3 ± 0.03 cm to 4.9 ± 0.05 cm, uterine wall thickness increased from 0.3 ± 0.03 cm to 0.8 ± 0.01 cm, and placental thickness increased from 0.1 ± 0.0 cm to 0.5 ± 0.05 cm. Chorionic cavity diameter, outer uterine diameter, and placental length each increased at a linear rate through day 37, after which time, each had a marked plateau in growth. Of the extra-fetal structures, chorionic cavity diameter was the most accurate for estimation of gestational age.

All of the fetal structures studied increased at an increasing (second order) rate. Crown-rump length increased from 0.3 ± 0.05 cm on day 24 to 9.2 ± 0.2 cm on day 48. Body diameter increased from 0.2 ± 0.03 cm on day 24 to 4.6 ± 0.15 cm on day 60. Head diameter increased from 0.8 ± 0.05 cm on day 34 to 2.7 ± 0.04 cm on day 60. Of the fetal structures, head diameter was the most accurate for estimation of gestational age.
Epidemiologie investigation of a silage-associated epizootic of ovine listeric encephalitis, using a new Listeria-selective enumeration medium and phage typing
Authors: Vázquez-Boland J. A. , Dominguez L. , Blanco M. , Rocourt J. , Fernández-Garayzábal J. F. , Gutiérrez C. B. , Tascón R. I. , Rodriguez-Ferri E. F.
Published: January 2024

The role of silage feeding in the origin of an epizootic of encephalitic listeriosis in a sheep flock was investigated by use of a new direct Listeria-selective isolation and enumeration medium, in combination with serotyping and phage typing. The silage contained high numbers (about 106 cells/g) of a L monocytogenes strain indistinguishable with respect to serovar and phagovar from that isolated from the brains of sick sheep. These results provided unambiguous bacteriologic evidence of the epidemiologic link between silage consumption and listeriosis in ruminants.
Intramammary administration of gentamicin as treatment or experimentally induced Escherichia coli mastitis in cows
Authors: Erskine J. , Wilson R. C. , Riddell M. G. , Tyler W. , Spears H. J. , Davis B. S.
Published: January 2024

In 8 Holstein cows, 50 colony-forming units (cfu) of Escherichia coli was administered into 1 mammary gland. Sections were established in all inoculated glands. In 4 of the 8 cows, 500 mg of gentamicin sulfate was administered by intramammary infusion 14 hours after inoculation; the other 4 cows were untreated controls. Infusions of gentamicin also were given after each of the 3 succesive milkings after the initial infusion, so that a total dose of 2 g of gentamicin was given to each of the treated cows.

During the 33-hour treatment period and for the first milking after the last infusion of gentamicin, the treated cows had a mean gentamicin concentration of ≥ 31.0 μg/ml in milk samples that were collected from inoculated quarters immediately before each milking. Concentrations of 0.34 and 0.69 μg of gentamicin/ml were detected in milk from 2 cows at 8 days after inoculation with E coli. Mean serum concentrations of gentamicin were ≥ 0.37 μg/ml throughout the treatment period and the first 0.2 hours after the last infusion, with a mean peak concentration of 0.96 μg/ml at 24.4 hours. The range of peak concentration of gentamicin detected in urine from all treated cows was 42 to 74.4 μg/ml.

Peak concentration of E coli in milk in the treated cows 6.08 ± 1.02 log10 cfu/ml) did not significantly (P > 0.05) differ from that of the control cows (5.26 ± 1.00 log10 cfu/ml). Similarly, mean duration of infection in the treated cows (54 hours) did not differ significantly from that of the control cows (48 hours). The treatment groups also did not differ significantly in peak concentrations of albumin or IgGl in milk, although mean concentrations of albumin and IgGl at 16 hours after inoculation, and of albumin at 20 hours, was significantly (P < 0.05) higher in the milk from control cows than from the treated cows. Mean values of peak rectal temperature and of mean rectal temperature throughout the trial did not differ between the groups. At the end of the 4-week trial, 1 of 4 inoculated glands in treated cows and 3 of 4 in control cows had somatic cell counts less than or equal to preinoculation concentrations (5.18 log10 cells/ml).

Intramammary administration of gentamicin did not affect the duration or severity of experimentally induced E coli mastitis. In addition, substantial concentrations of gentamicin were detected in the serum of treated cows, suggesting that intramammary treatment may result in prolonged drug residues in tissue
Healing of segmental grafts of digital pad skin in dogs
Authors: Swaim Steven F. , Riddell Kay P. , Powers Robert D.
Published: January 2024

Pad grafts would be indicated in instances of severe paw trauma when there has been loss of the major weight-bearing pads (ie, metatarsal and metacarpal pads) as well as loss of the digital pads. A practical technique for replacing pad tissue on the remaining paw tissue could avert limb amputation for lack of weight-bearing tissue in the area.

Small segmental digital pad grafts were placed in granulation tissue beds in dogs. Although the grafts were from thick pad skin, they healed well. However, intervening wound areas did not become covered with the heavier keratinized epithelium of the pads. The thinner, more rapidly growing, less keratinized epithelium from the wound edges covered most of the wound.
Percutaneous ultrasound-guided cholecystocentesis in cows
Authors: Braun Ueli , Gerber David
Published: January 2024

A method was developed for percutaneous ultrasound-guided cholecystocentesis in cattle. The procedure was performed on the right side in the 9th, 10th, or 11th intercostal space of 30 cows. Of the 30 cows, 20 were slaughtered 24 hours after cholecystocentesis and the remaining 10 cows were slaughtered after a 10-day observation period. Changes in the peritoneum and gallbladder wall, observed at slaughter, were minimal. During the 10-day observation period, general behavior, attitude, and ap-petite of the 10 cows were normal. A transient, slight increase in rectal temperature was observed in 6 cows at 4, 5, or 8 days after cholecystocentesis. Total and differential wbc counts and total protein and fibrinogen concentrations, determined daily, were all within normal ranges. Bile samples from 20 cows were examined microscopically and biochemically. Fasciola hepatica and Dicrocoelium dendriticum eggs were observed in bile from 7 and 12 cows, respectively. Fecal examination revealed F hepatica eggs in 4 cows; D dendriticum eggs were not identified in any of the fecal samples. In 1 cow, F hepatica eggs were observed in the feces, but not in the bile. Bile acids concentration in bile varied from 12.5 to 68.5 mmol/ L (mean ± SD, 45.3 ± 3.05 mmol/L) and in serum from 3.8 to 281.0 μmol/L (41.6 ± 17.24 μmol/L). Negative correlation was obtained between bile acids concentration in bile and that in serum (r = −0.60, P < 0.01). It was concluded that percutaneous ultrasound-guided cholecystocentesis in cows is a safe procedure and that microscopic and biochemical examinations of obtained bile can be useful diagnostic aids.
Risk factors for abomasal volvulus and left abomasal displacement in cattle
Authors: Constable Peter D. , Miller Gay Y. , Hoffsis Glen F. , Hull Bruce L. , Rings D. Michael
Published: January 2024

A hospital-based case-control study was conducted to evaluate and compare risk factors for abomasal volvulus (av) and left displaced abomasum (lda) in cattle. Medical record abstracts were derived from 17 North American veterinary schools by the Veterinary Medical Data Program for all cattle admitted between Jan 1, 1977 and Dec 31, 1986, and for those with a diagnosis of av or lda. From a total of 108,956 individual cattle records, 1,036 cases of av and 7,695 cases of lda were identified, with a ratio of LDA to AV cases of 7.4 to 1. In-hospital mortality was 23.5% for av and 5.6% for lda.

Age, breed, gender, and season each had significant (P < 0.05) effects on risk for av and lda. Risk for av and lda increased with increasing age, with greater risk in cattle aged 4 to 7 years. Dairy cattle were at higher risk of developing av (adjusted odds ratio, 36.4) and lda (adjusted odds ratio, 95.2) than were beef cattle. The odds of AV in Brown Swiss cattle were significantly (P < 0.0001) lower, and the odds of lda in Guernsey cattle were significantly (P < 0.0001) higher than those in Holstein cattle. Female cattle were also at higher risk of developing av (adjusted odds ratio, 3.3) and lda (adjusted odds ratio, 29.1) than were male cattle. The odds of av and LDA varied considerably throughout the year, with the lowest number of cases observed in autumn. Seasonal development of AV differed significantly (P < 0.0001) from that of LDA, with the odds of av and lda being highest in January and March, respectively.

The medical records for all cattle with av and lda examined at the teaching hospital over a 10- and 5-year period, respectively, were reviewed, and the time interval since parturition, as well as the existence and nature of concurrent disease, were recorded. Proportionately fewer cases of av than lda developed during the first 2 weeks after parturition (28.3% of av cases vs. 57.0% of lda cases). Concurrent disease existed in 30.4% of av cases and 53.6% of LDA cases, with the rates of concurrent disease differing significantly (P < 0.0001) between the 2 groups. The mis-classification rate for data generated at the teaching hospital was estimated to be 6.5% for av and 5.3% for lda.

On the basis of the findings of this study, we hypothesize that: abomasal atony is a prerequisite for av and lda; existence of an abdominal void immediately after parturition facilitates development of AV and lda; normal rumen volume provides a moderately effective barrier against lda; risk of lda does not increase appreciably with advancing pregnancy; and the direction of abomasal displacement (av or lda) after abomasal atony and dilation is influenced principally by rumen volume.
Effects of copper deficiency on T-cell mitogenic responsiveness and phenotypic profile of blood mononuclear cells from swine
Authors: Bala S. , Lunney J. K. , Failla M. L.
Published: January 2024

The effect of dietary copper deficiency on T-cell mitogenic responsiveness and phenotypic profile of blood mononuclear cells (mnc) in weaned pigs was examined. Outbred, weaned pigs were fed a semipurified diet containing adequate (6.4 mg/kg of body weight) or deficient (0.8 mg/kg) amounts of Cu. Pigs fed the low Cu diet for 10 weeks had markedly decreased concentrations of Cu in liver and plasma, and hypertrophic hearts. In vitro reactivity of mnc from Cu-deflcient pigs to phytohemagglutinin and concanavalin A was significantly suppressed. This functional impairment was not associated with a decrease in the percentages of T cells, CD4 or CD8 cell subsets, or B cells. Expression of sla-dq and sla-dr class II major histocompatibility complex (mhc) antigens was increased by Cu deficiency, the former significantly. Unlike rodents, in which inadequate Cu nutriture induces functional T cell deficiency that is associated with a decrease in the CD4 T-cell subset, swine fed inadequate Cu diets for 10 weeks had no changes in mhc subsets yet clearly manifested functional impairment of T-cell responses.
Changes in cross-sectional area and capillary supply of the muscle fiber population in equine gluteus medius muscle as a function of sampling depth
Authors: Rivero José Luis L. , Serrano Antonio L. , Diz Andrés M. , Morales José L.
Published: January 2024

The right and left gluteus medius muscles of 4 mature Andalusian stallions were examined by repeated needle biopsy over a specific area and depth, as well as at different depths, to determine whether the cross-sectional area and capillary supply of the various fiber types are homogeneous throughout the muscle. The muscle biopsy specimens were histochemically analyzed for fiber types (myofibrillar adenosine triphosphatase) and capillaries (amylase-periodic acid-Schiff method). Differences between contralateral sites were not identifiable for any of the analyzed variables. Differences between sampling depths were larger than those between sample sites. The percentage of type-1 fibers increased, and that of type-2B fibers decreased as a function of increased sampling depth, but the relative frequency of type- 2A fibers did not change with depth. The mean crosssectional area of type-1 and type-2A fibers increased significantly, and that of type-2B fibers decreased between the most superficial and the deepest sampling sites. The capillary density and the mean number of capillaries per fiber increased as a function of sampling depth, but significant changes were not recorded between sampling depths for overall mean fiber area. The mean number of capillaries in contact with fibers of each histochemical type increased significantly with increasing sampling depth only for type- 1 fibers. However, the number of capillaries in contact with fibers changed significantly, relative to the fiber area, as a function of sampling depth; for type- 28 fibers this variable increased, whereas for type-2A and type-1 fibers, it decreased. These results indicate that fiber size and capillary supply of the various fiber types in the gluteus medius muscle of horses vary as a function of depth. These patterns of variation most likely indicate the functional difference between various portions of the muscle, and support the general opinion that the functional demands placed on the fiber population are an important factor in the development of muscle fiber properties.
Type-I interferon genotypes and severity of clinical disease in cattle inoculated with bovine herpesvirus 1
Authors: Ryan Anne M. , Hutcheson David P. , Womack James E.
Published: January 2024

Genomic DNA samples and health records from 98 unrelated, mixed-breed cattle inoculated with bovine herpesvirus 1 (bhv-1) were examined to determine the relationship between interferon (ifn) genotype and severity of clinical disease. Cattle were retrospectively classified as moderately or severely affected on the basis of rectal temperature, feed intake, and weight gain after intranasal inoculation of bhv-1. Southern blot analysis of 16 type-I ifn genes identified alleles at 3 ifn loci (IFNB1, IFNW4, and IFNW8) that were significantly associated with the more severe clinical phenotype (odds ratios = 4.1 [P= 0.01], 2.3 [P< 0.05] and 2.4 [P= 0.06], respectively). A second allele at the IFNB1 locus was associated with the milder disease phenotype (odds ratio = 2.9, P< 0.05). These results indicate that selective breeding programs aimed at altering the frequency of these alleles in cattle populations may potentially improve animal health and lessen the economic impact of bhv-1 infection on cattle producers.
Total and differential leukocyte counts, N-acetyl-ß-D-glucosamtnidase activity, and serum albumin content in foremilk and residual milk during endotoxin-induced mastitis in cows
Authors: Östensson K.
Published: January 2024

Foremilk, residual milk, and blood samples were studied for 10 days during acute mastitis episodes induced by endotoxin infused via the teat canal. Quarter milk and blood samples were collected frequently for 3 days after the infusion and thereafter once or twice daily. Leukocyte concentration in milk and blood was determined by flow cytometry. Within 2 hours after infusion of the endotoxin, clinical mastitis was observed. Total leukocyte concentration and proportion of neutrophils increased significantly (P < 0.05) by postinfusion hour (pih) 2 in foremilk and by pih 4 in residual milk. From Pill 2, serum albumin content and N-acetyl-ß-D-glucosaminidasc activity were significantly increased in both fractions. Neutrophils were the predominant leukocyte population in both fractions until Pin 59. From pih 72, lymphocytes were the predominant cell population until pih 175 in foremilk and until pih 223 in residual milk. Serum albumin content and N-acetyl-ß-D-glucosamin-idase activity in residual milk was significantly lower than in foremilk from pih 4 to 24 and from pih 24 to 59, respectively. Regarding total and differential leukocyte counts, values for the 2 fractions followed the same pattern throughout the course of inflammation, probably owing to frequent sample collection. Total and differential cell counts tended to differ between the fractions during some periods, although differences were not statistically significant. When samples were taken less frequently, the total leukocyte concentration in residual milk was higher than that in foremilk. Although sample collections were frequent, clustering of immature neutrophils was not observed in the cytofluorogram of blood leukocytes in this study.

Residual milk seems to be the fraction that best reflects the condition in the quarter at the particular time when the milk sample is taken. Results also indicate that residual milk reflects the condition of the secretory tissue, as well as the lower regions of the gland.
Resuscitation of anesthetized endotoxemic pigs by use of hypertonic saline solution containing dextran
Authors: Ilellyer Peter W. , Meyer Robert E. , Olson Neil C.
Published: January 2024

We evaluated the biochemical and hemodynamic response to hypertonic saline solution plus dextran in isoflurane-anesthetized pigs infused IV with Escherichia coli endotoxin (5 μg/kg of body weight for 0 to 1 hour + 2 μg/kg for 1 to 4 hours). After 120 minutes of endotoxemia, pigs were treated with a bolus (4 ml/kg over 3 minutes) of either normal saline solution (NSS; 0.9% NaCI), or hypertonic saline solution plus dextran (HSSD; 7.5% NaCI + 6% dextran-70). Administration of HSSD significantly (P < 0.05) increased serum osmolality and concentrations of sodium and chloride for approximately 2 hours during endotoxemia. Plasma total protein concentration decreased significantly (P < 0.05) for 2 hours after treatment with HSSD, indicating hemodilution and increased plasma volume. Although HSSD transiently increased cardiac index (CI) for approximately 15 minutes, this effect was not sustained; however, the endotoxin-induced decrease in CI was ameliorated from 120 to 180 minutes. In pigs of the endotoxin + NSS group from 180 to 240 minutes, CI decreased significantly (P < 0.05), compared with baseline and control values. The endotoxin-induced increases in mean pulmonary arterial pressure and pulmonary vascular resistance were not attenuated by HSSD. At 135 minutes, total peripheral vascular resistance was transiently lower (for approx 15 minutes) in pigs treated with HSSD, compared with control pigs. The endotoxin-induced increase in plasma lactate concentration was not attenuated by HSSD, indicating continued peripheral O2 debt. We conclude that, despite sustained increases in serum osmolality and concentrations of sodium and chloride, HSSD has only transiently beneficial cardiopulmonary effects during endotoxemia in pigs.
Prevalence of mycoplasmal and ureaplasmal recovery from tracheobronchial lavages and prevalence of mycoplasmal recovery from pharyngeal swab specimens in dogs with or without pulmonary disease
Authors: Randolph J. F. , Moise N. S. , Scarlett J. M. , Shin S. J. , Blue J. T. , Bookbinder P. R.
Published: January 2024

The prevalence of mycoplasmal and ureaplasmal recovery from tracheobronchial lavage specimens and the prevalence of mycoplasmal recovery from pharyngeal swab specimens from dogs with (n = 38) or without (n = 26) pulmonary disease were determined. Similar mycoplasmal recovery rates were found for tracheobronchial lavage specimens from dogs ≥ 1 year old with (21%) or without (25%) pulmonary disease. Prevalence of mycoplasmal recovery from tracheobronchial lavages was significantly associated with pulmonary disease among dogs < 1 year old (P = 0.04), and with dogs that had concurrent Bordetella (P = 0.006) and Streptococcus (P = 0.05) isolations. Among dogs with pulmonary disease, mycoplasmas were significantly (P = 0.02) more prevalent in dogs with septic inflammation than in dogs with nonseptic inflammation of the tracheobronchial tree. Ureaplasmas were only isolated from a tracheobronchial lavage specimen of 1 dog with pulmonary disease and from none of the dogs without pulmonary disease. Most dogs with (84%) and all dogs without pulmonary disease had mycoplasmas isolated from the pharynx.

Seemingly, mycoplasmas are part of the normal pharyngeal flora of most dogs and normal inhabitants of the lower airway in about a fifth to a fourth of the canine population ≥ 1 year old. Dogs < 1 year old with pulmonary disease and dogs with concurrent Bordetella or tracheobronchial streptococcal isolations may be more susceptible to mycoplasmal colonization of the lower airways. Seemingly, ureaplasmas are rarely associated with pulmonary disease, and are not normal inhabitants of the trachea and bronchi of dogs.
Pharmacokinetics of ibuprofen in lactating dairy goats
Authors: DeGraves Fred J. , Anderson Kevin L. , Aucoin David P.
Published: January 2024

Pharmacokinetic variables of ibuprofen were studied in 6 adult lactating dairy goats after single administration of the drug (14 and 25 mg/kg of body weight, IV, and 50 and 100 mg/kg, PO). Each of the goats was given all doses, with a minimum of 1 week between doses. Ibuprofen concentration in serum was analyzed by use of high-performance liquid chromatography. The lower limit of detection for the ibuprofen assay was 50 ng/ml.

Ibuprofen pharmacokinetic variables after IV administration best fit an open two-compartment model. Geometric mean (range) volume of distribution at steady state was 0.16 (0.11 to 0.19) and 0.17 (0.15 to 0.19) L/kg, and terminal half-life was 1.08 (0.79 to 1.70) and 1.27 (1.03 to 1.88) hours, for ibuprofen dosages of 14 and 25 mg/kg, respectively. After 50 and 100 mg/kg administered orally, bioavailability was 90.8 and 106%, respectively. Area under the curve increased linearly with dose administered. Adverse effects were not observed in goats given ibuprofen.
In vitro susceptibility of Actinobacillus pleuropneumoniae strains to 42 antimicrobial agents
Authors: Gutiérrez César B. , Píriz Segundo , Vadillo Santiago , Rodríguez Ferri Elías F.
Published: January 2024

Minimal inhibitory concentration of 42 antimicrobial agents was determined against 57 field strains of Actinobacillus pleuropneumoniae isolated from pigs in Spain. Penicillins, aminoglycosides, and tetracyclines had irregular activity; ticarcillin, tobramycin, and doxycycline were the most active of each group, respectively. Macrolides, vancomycin, dapsone, and tiamulin, to which strains had high rate of resistance, were almost ineffective. Thiamphenicol, colistin, rifampin, fosfomycin, mupirocin, and metronidazole had good activity, with resistance ranging between 0 and 8.8%. Finally, cephalosporins (except cephalexin) and quinolones (especially ciprofloxacin, enrofloxacin, and sparfloxacin) were the most active antibiotics against A pleuropneumoniae.
Comparison of taurine, α-tocopherol, retinol, selenium, and total triglycerides and cholesterol concentrations in cats with cardiac disease and in healthy cats
Authors: Fox Philip R. , Trautwein Elke A. , Hayes K. C. , Bond Betsy R. , Sisson D. David , Moise N. Sydney
Published: January 2024

Epidemiologic relations were evaluated between plasma concentrations of nutrients and cardiovascular diseases. A total of 220 cats were assessed: 144 cats with noninduced acquired heart disease and 76 clinically normal cats. Plasma was assayed for taurine, α-tocopherol, selenium, retinol, and total cholesterol and triglycerides concentrations. Cardiovascular disease groups included dilated cardiomyopathy (n = 53), left ventricular hypertrophy (n = 28), hyperthyroidism (n = 11), and uncertain classification (n = 52).

In cats with dilated cardiomyopathy, mean plasma taurine concentration was the lowest of that in cats of any group, being only 38% of the value in healthy cats; females had less than half the mean value of males. Tocopherol concentration was 20% lower than normal, and retinol concentration was 40% higher than normal. Total cholesterol concentration was 36% lower than normal. Triglycerides concentration was higher in these cats than in any other group — twice the value recorded in healthy cats and 67% higher than that in hyperthyroid cats.

In cats with hypertrophic cardiomyopathy, almost 15% had mean plasma taurine concentration < 30 μmol/L. Retinol concentration was 15% higher, and triglycerides concentration was 54% higher than normal. Approximately 27% of hyperthyroid cats had mildly decreased plasma taurine concentration. Hyperthyroid cats had the lowest tocopherol and cholesterol values; both were at least 30% lower than normal. Retinol concentration was 30% higher than normal.

Approximately 14% of cats with uncertain classification had mildly decreased plasma taurine concentration. Plasma retinol and triglycerides concentrations were higher than normal in 25 and 38% of these cats, respectively.

Plasma selenium concentration, compared between healthy cats and cats with cardiac disease, was not significantly different. This observation may not be meaningful, however, in light of the limited number of cats in which selenium was assessed.

Although significant correlation was not observed between plasma taurine and plasma retinol, tocopherol, or cholesterol concentrations in cats with cardiac disease, plasma tocopherol and cholesterol values were highly associated (P < 0.01). Also, the molar ratio of cholesterol to tocopherol was significantly (P < 0.05) lower in cats with dilated cardiomyopathy, compared with healthy cats.
3α-Hydroxylated bile acid profiles in clinically normal cats, cats with severe hepatic lipidosis, and cats with complete extrahepatic bile duct occlusion
Authors: Center S. A. , Thompson M. , Guida L.
Published: January 2024

Concentrations of 3α-hydroxylated bile acids were measured in serum and urine of clinically normal (healthy) cats (n = 6), cats with severe hepatic lipidosis (n = 9), and cats with complete bile duct occlusion (n = 4). Bile acid concentrations were measured by use of a gradient flow high-performance liquid chromatography procedure with an acetonitrile and ammonium phosphate mobile phase and an in-line postanalytic column containing 3α-hydroxysteroid dehydrogenase and a fluorescence detector. Specific identification of all bile acid peaks was not completed; unidentified moieties were represented in terms of their elution time (in minutes). Significant differences in serum and urine bile acid concentrations, quantitative and proportional, were determined among groups of cats. Cats with hepatic lipidosis and bile duct occlusion had significantly (P ≥ 0.05) greater total serum and urine bile acids concentrations than did healthy cats. The proportion of hydrophobic bile acids in serum, those eluting at ≥ 400 minutes, was 1.9% for healthy cats, 3.3% for cats with lipidosis, and 5.4% for bile duct-obstructed cats. Both groups of ill cats had a broader spectrum of unidentified late-eluting serum bile acids than did healthy cats; the largest spectrum developed in bile duct-occluded cats. The trihydroxy-to-dihydroxy serum bile acids ratio was 8.8:1 for healthy cats; 24.1:1 for cats with lipidosis; and 20:1 for cats with bile duct obstruction. There was a paucity of glycine-conjugated bile acids in all cats and small quantities of secondary bile acids in ill cats. A significantly (P < 0.05) smaller proportion of unconjugated primary bile acids was detected in sera from ill cats. Serum taurolithocholic acid was detected only in small quantities in cats of each group. There was significantly increased quantity, but lower proportion, of trihydroxy-cholestanoic acid in serum from ill cats, compared with healthy cats. A significantly (P < 0.05) greater proportional amount of unidentified moieties eluting at 130 and 277 minutes was detected in urine of cats with hepatic lipidosis; we believe that the unidentified moiety eluting at 277 minutes is tauroallocholic acid. Large proportional amounts of taurocholic and cholic acids were detected in urine of all cats, but ill cats had significantly (P < 0.05) greater quantities (quantitatively and proportional). Ill cats had significantly (P < 0.05) more taurocholic than cholic acid in urine. Because taurine is an essential amino acid for cats and is a necessary daily dietary constituent, large urinary losses of taurine in conjugated bile acids may further compromise the health of anorectic cats with severe hepatic lipidosis.
Pharmacokinetic model for predicting sulfamethazine disposition in pigs
Authors: Sweeney Raymond W. , Bardalaye Promode C. , Smith Craig M. , Soma Lawrence R. , Uboh Cornelius E.
Published: January 2024

Concentration of sulfamethazine was measured in plasma and tissues (fat, liver, kidney, spleen, lungs, and skeletal muscle) of pigs given the drug iv and po. The plasma concentration vs time curve was best described by a 2-compartment model, with a distribution half-life of 0.46 hour and an elimination halflife of 16.9 hours. Bioavailability after oral administration was 85.8 ± 5.3%.

The tissue and plasma sulfamethazine concentration vs time data were used to develop a multicompartment pharmacokinetic model of sulfamethazine disposition in pigs. Plasma and tissue concentrations of sulfamethazine in pigs were measured at various intervals after multiple oral doses of sulfamethazine, and were compared to concentrations predicted by the model. Model predictions for tissue concentrations of sulfamethazine after addition of the drug to feed (110 μg/g of feed for 98 days; 550 μg/g for 30 days) were compared to results from other studies. The model accurately predicted the number of days for sulfamethazine concentration to fall below 0.1 μg of tissue/g (0.1 ppm, the tolerated concentration) in various tissues.
Antagonism by flumazenil of midazolam-induced changes in quantitative electroencephalographic data from isofluraneanesthetized dogs
Authors: Keegan R. D. , Greene S. A. , Moore M. P. , Gallagher L. V.
Published: January 2024

Quantitative electroencephalography (qeeg) was assessed in 5 dogs anesthetized with 1.6% end-tidal concentration of isoflurane and after subsequent administration of the benzodiazepine midazolam (0.2 mg/kg of body weight, iv). Ventilation was controlled to maintain normocapnia. Effect of the benzodiazepine antagonist, flumazenil (0.04 mg/kg, iv), on qeeg in midazolam-isoflurane-anesthetized dogs was determined. Heart rate, arterial blood pressure, esophageal temperature, arterial pH and blood gas tensions, endtidal CO2 concentration, and end-tidal isoflurane concentration were monitored throughout the study. A 21-lead linked-ear montage was used for recording the eeg data. Quantitative eeg data were stored on an optical disk for later analysis. Values for absolute power of eeg were determined for δ-, θ-, α-, and β-frequencies. Cardiovascular variables remained stable throughout the study. Midazolam administration was associated with decreased absolute power in all frequencies of eeg at all electrode sites. Administration of flumazenil antagonized midazolam-induced decreased absolute power of eeg in all frequencies at all electrode sites. We conclude that qeeg provides a noninvasive, objective measure of midazolamand flumazenil-induced changes in cortical activity during isoflurane anesthesia.
Effects of clenbuterol hydrochloride on pulmonary gas exchange and hemodynamics in anesthetized horses
Authors: Dodam John R. , Moon Richard E. , Olson Neil C. , Exposito Andres J. , Fawcett Thomas A. , Huang Y. C. , Theil David R. , Camporesi Enrico , Swanson Clifford R.
Published: January 2024

We evaluated the effects of clenbuterol HCl (0.8 μg/kg, of body weight, iv), a β2, agonist, on ventilation-perfusion matching and hemodynamic variables in anesthetized (by iv route), laterally recumbent horses. The multiple inert gas elimination technique was used to assess pulmonary gas exchange. Clenbuterol HCl induced a decrease in arterial oxygen tension (from 57.0 ± 1.8 to 49.3 ± 1.2 mm of Hg; mean ± sem) as a result of increased shunt fraction (from 6.6 ± 2.1 to 14.4 ± 3.1%) and ventilation to regions with high ventilation-perfusion ratios. In contrast, no changes in these variables were found in horses given sterile water. In horses given clenbuterol HCl, O2 consumption increased from 2.23 ± 0.18 to 2.70 ± 0.14 ml · min-1 · kg-1, and respiratory exchange ratio decreased from 0.80 ± 0.02 to 0.72 ± 0.01. Respiratory exchange ratio and O, consumption were not significantly modified in sterile water-treated (control) horses. Clenbuterol HCl administration was associated with increased cardiac index (from 57.4 ± 4.0 to 84.2 ± 6.3 ml. min-1 · kg-1), decreased total peripheral vascular resistance (from 108.3 ± 9.3 to 47.6 ± 2.8 mm of Hg · s · kg · ml-1), and decreased pulmonary vascular resistance (from 31.3 ± 3.8 to 13.6 ± 0.7 mm of Hg · s · kg · ml-1). Our findings indicated that clenbuterol HCl may potentiate hypoxemia as a result of increased shunt fraction in horses anesthetized by the iv route, and caused changes in hemodynamic variables that were consistent with its ability to stimulate β2-adrenergic receptors.