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OBJECTIVE To evaluate cardiac output (CO) measurements using transpulmonary ultrasound (TPUD) technology and compare results with those of the gold standard, pulmonary arterial catheter thermodilution (PACTD), in 6 healthy anesthetized pigs during acute hemodynamic changes caused by manipulation of the blood volume. ANIMALS 6 healthy male Landrace pigs. PROCEDURES Over a period of 1 week, pigs were anesthetized with isoflurane, mechanically ventilated, and underwent instrumentation in dorsal recumbency. They were subjected to sequential experimental states during which the blood volume was manipulated so that the animals transitioned from normovolemia to hypovolemia (20% and 40% of blood volume depletion), back to normovolemia (autologous blood transfusion), and then to hypervolemia (following colloid bolus). During each volume state, CO measurements were compared between TPUD and PACTD. RESULTS The mean ± SD relative bias between TPUD and PACTD was 7.71% ± 21.2% with limits of agreement –33.9% to 49.3%, indicating TPUD slightly underestimated CO values, compared with values obtained with PACTD. The mean ± SD of the bias between the 2 methods was 0.13 ± 0.5 L/min. Only 5 of 36 (13.9%) TPUD CO measurements had an absolute value of relative bias > 30%. The percentage error calculated for TPUD was 29.4%. CLINICAL RELEVANCE Results suggested that TPUD measurements have acceptable agreement with PACTD measurements. Moreover, TPUD exhibits promising potential in being used interchangeably with PACTD for future hemodynamic research involving swine as species of interest. [ABSTRACT FROM AUTHOR]

OBJECTIVE To describe an ultrasound-guided technique for central venous catheter placement via the external jugular vein (EJV) in pigs. ANIMALS 96 healthy Landrace-Poland China barrows (approx 16 weeks old with a mean weight of 70 kg). PROCEDURES Pigs were anesthetized. With ultrasound guidance, a needle was inserted into the EJV without a large incision or cutdown procedure. A guidewire was inserted through the needle into the vein. A modified Seldinger technique was used to advance a catheter into the vessel until the tip was in the cranial vena cava near the right atrium. A trocar was used to create a tunnel through the subcutaneous tissues from the catheter insertion site to between the dorsal borders of the scapulae. The free end of the catheter was passed through that tunnel. An extension was attached to the catheter and secured to the skin. Pigs were euthanized and underwent necropsy at completion of the study for which they were catheterized. RESULTS Central venous catheters were successfully placed in all 96 pigs and facilitated collection of serial blood samples with minimal stress. Catheters remained in place for a mean of 6 days (range, 4 to 10 days). Necropsy revealed abscesses along the subcutaneous catheter tract in 9 pigs. Twenty pigs had histologic evidence of phlebitis and fibroplasia in the cranial vena cava. CONCLUSIONS AND CLINICAL RELEVANCE The described technique, in combination with extensive socialization, allowed serial collection of blood samples with minimal stress and restraint and is an alternative to surgical cutdown procedures for catheter placement. [ABSTRACT FROM AUTHOR]

Objective: This study assessed the use of a topical anesthetic as a feasible approach to reduce pain during piglet castration using a minimal anesthesia protocol., Animals: 18 male piglets, aged 3-6 days, were included in this study., Methods: A minimal anesthetic state was induced with isoflurane administered by facemask, with anesthetic depth individually adjusted based on responses to interdigital pinch. To desensitize the scrotal skin, a vapocoolant was applied 3 times. Scrotal incisions were made subsequently and Tri-Solfen (TS) or Placebo (P) was administered in both incisional gaps. After 30 seconds, the spermatic cords were severed followed by a further application of TS/P to both incision edges. Nociception-related variables, such as mean arterial blood pressure (MAP), heart rate (HR), and nocifensive movements, were assessed., Results: Significant differences in MAP changes were assessed between the TS (14 ± 4 mmHg) and the P group (36 ± 8 mmHg) for cutting the spermatic cords. Furthermore, significantly fewer nocifensive movement score points appeared in the TS than in the P group (0; IQR = 0 vs 5; IQR = 6)., Clinical Relevance: In this anesthesia model, the application of TS after skin incision significantly reduced MAP responses and nocifensive movements with spermatic cord transection compared with the application of P. However, the waiting period between TS-application and spermatic cord transection might limit the benefit of the method in conscious piglets, as pain during castration is reduced but additional stress is caused by the prolonged handling. Furthermore, using a vapocoolant did not provide anesthesia for skin incisions.

OBJECTIVE To evaluate the use of a modified passive leg-raising maneuver (PLRM) to predict fluid responsiveness during experimental induction and correction of hypovolemia in isoflurane-anesthetized pigs. ANIMALS 6 healthy male Landrace pigs. PROCEDURES Pigs were anesthetized with isoflurane, positioned in dorsal recumbency, and instrumented. Following induction of a neuromuscular blockade, pigs were mechanically ventilated throughout 5 sequential experimental stages during which the blood volume was manipulated so that subjects transitioned from normovolemia (baseline) to hypovolemia (blood volume depletion, 20% and 40%), back to normovolemia, and then to hypervolemia. During each stage, hemodynamic variables were measured before and 3 minutes after a PLRM and 1 minute after the pelvic limbs were returned to their original position. The PLRM consisted of raising the pelvic limbs and caudal portion of the abdomen to a 15° angle relative to the horizontal plane. RESULTS Hemodynamic variables did n o t vary in response to the PLRM when pigs were normovolemic o r hypervolemic. When pigs were hypovolemic, the PLRM resulted in a significant increase in cardiac output and decrease in plethysomographic variability index and pulse pressure variation. When the pelvic limbs were returned to their original position, cardiac output and pulse pressure variation rapidly returned to their pre-PLRM values, but the plethysomographic variability index did not. CONCLUSIONS AND CLINICAL RELEVANCE Results suggested a modified PLRM might be useful for identification of hemodynamically unstable animals that are likely to respond to fluid therapy. Further research is necessary to validate the described PLRM for prediction of fluid responsiveness in clinically ill animals. [ABSTRACT FROM AUTHOR]

Objective: The lactulose-to-mannitol ratio test is a test to assess the disorders associated with gut permeability. The test requires an oral administration of the mixture of lactulose and mannitol and urine collection. The urinary ratio of lactulose to mannitol is an indicator of intestinal permeability. Due to the complexity of urine collection in animal studies, plasma exposure ratios of lactulose to mannitol compared to their urinary concentration ratios were evaluated following an oral administration of the sugar mixture in pigs., Animals: 10 pigs were orally dosed with a solution of lactulose and mannitol mixture., Procedures: Plasma samples were collected at predose, 10 and 30 minutes and 2, 4, and 6 hours postdosing, and cumulated urinary samples were collected at 6 hours for liquid chromatography-mass spectrometry analysis. The ratios of pharmacokinetic parameters of lactulose to mannitol and the plasma sugar ratios at a single time point or the mean values of several time points were compared to their urinary sugar ratios., Results: The results revealed that the lactulose-to-mannitol ratios of AUC0-6h, AUCextrap, and Cmax were correlated to the urinary sugar ratios, and the plasma sugar ratios of a single time point at 2, 4, or 6 hours and the mean values of those time points were also appropriate to replace their urinary ratios in pigs., Clinical Relevance: Following an oral administration of lactulose and mannitol mixture, blood collection, and assay can be an option for assessing intestinal permeability, especially in animal studies.

The term reverse zoonosis specifically refers to the natural transmission of disease and infection from humans to animals, with humans as the reservoir host replicating the infectious agent. In the last 20 years, reverse zoonosis has increasingly garnered attention because of human disease outbreaks. In this Currents in One Health article, the author will review host range as the main risk factor for reverse zoonosis, with an emphasis on influenza A virus (IAV) disease events in humans and other species in the context of a "One Health" approach to gain a better understanding of their transmission routes to facilitate their control and prevent them from occurring. The human-to-pig transmission of IAV represents the largest reverse zoonosis of a pathogen documented to date. At the same time, the 2022 farmed mink outbreak in Spain is the most sustained mammal-to-mammal transmission of the highly pathogenic avian influenza (HPAI) H5N1 since its re-emergence in humans in 2003. Without any prospect of eradicating IAVs, the best way to mitigate the impact of IAV reverse zoonosis is by vaccinating humans and susceptible farmed and pet animals. The recent major reverse zoonoses involving other virus groups (Coronaviridae, Poxviridae, arboviruses, and the human respiratory viruses transmitted to endangered non-human primate species) and the prevention and control of reverse zoonoses are addressed in the companion Currents in One Health by Kibenge, JAVMA, June 2023.

Objective: To develop a trivalent genetically engineered inactivated Escherichia coli vaccine (K88ac-3STa-LTB) that neutralizes the STa toxin by targeting fimbriae and entertoxins for the treatment of enterotoxigenic E coli., Animals: 18- to 22-g mice, rabbits, pregnant sows., Procedures: Using PCR, the K88ac gene and LTB gene were cloned separately from the template C83902 plasmid. At the same time, the 3 STa mutant genes were also amplified by using the gene-directed mutation technology. Immune protection experiments were performed, and the minimum immune dose was determined in mice and pregnant sows., Results: The ELISA test could be recognized by the STa, LTB, and K88ac antibodies. Intragastric administration in the suckling mouse confirmed that the protein had lost the toxicity of the natural STa enterotoxin. The results of the immune experiments showed that K88ac-3STa-LTB protein could stimulate rabbits to produce serum antibodies and neutralize the toxicity of natural STa enterotoxin. The efficacy test of the K88ac-3STa-LTB-inactivated vaccine showed that the immune protection rate of the newborn piglets could reach 85% on the first day after suckling. At the same time, it was determined that the minimum immunization doses for mice and pregnant sows were 0.2 and 2.5 mL, respectively., Clinical Relevance: This research indicates that the K88ac-3STa-LTB trivalent genetically engineered inactivated vaccine provides a broad immune spectrum for E coli diarrhea in newborn piglets and prepares a new genetically engineered vaccine candidate strain for prevention of E coli diarrhea in piglets.

OBJECTIVE To determine the minimum infectious dose of porcine epidemic diarrhea virus (PEDV) in virus-inoculated feed. ANIMALS 30 crossbred 10-day-old pigs. PROCEDURES Tissue culture PEDV was diluted to form 8 serial 10-fold dilutions. An aliquot of stock virus (5.6 X 105 TCID50/mL) and each serial PEDV dilution were mixed into 4.5-kg batches of feed to create 9 PEDV-inoculated feed doses; I virus-negative dose of culture medium in feed was also created. Pigs were challenge exposed via oral administration of PEDV-inoculated feed, and fecal swab specimens were collected. All pigs were euthanized 7 days after challenge exposure; fresh tissues were collected and used for PCR assay, histologic examination, and immunohistochemical analysis. RESULTS The PCR cycle threshold (Ct) decreased by approximately 10 when PEDV was added to feed, compared with results for equivalent PEDV diluted in tissue culture medium. Pigs became infected with PEDV when challenge exposed with the 4 highest concentrations (lowest concentration to cause infection, 5.6 X 10¹ TCID50/g; Ct = 27 in tissue culture medium and 37 in feed). CONCLUSIONS AND CLINICAL RELEVANCE In this study, PEDV in feed with detectable Ct values of 27 to 37 was infective. The Ct was 37 for the lowest infective PEDV dose in feed, which may be above the limit of detection established for PEDV PCR assays used by some diagnostic laboratories. Overall, results indicated 5.6 X 10¹ TCID50/g was the minimum PEDV dose in feed that can lead to infection in 10-day-old pigs under the conditions of this study. [ABSTRACT FROM AUTHOR]

OBJECTIVE To compare the characteristics and multipotential and in vivo cartilage formation capabilities of porcine adipose-derived stem cells (pASCs) with those of porcine skin-derived stem cell-like cells (pSSCs). ANIMALS Three 6-month-old female pigs and four 6-week-old female athymic mice. PROCEDURES Adipose and skin tissue specimens were obtained from each pig following slaughter and digested to obtain pASCs and pSSCs. For each cell type, flow cytometry and reverse transcription PCR assays were performed to characterize the expression of cell surface and mesenchymal stem cell markers, and in vitro cell cultures were performed to determine the adipogenic,osteogenic,and chondrogenic capabilities. Each cell type was then implanted into athymic mice to determine the extent of in vivo cartilage formation after 6 weeks. RESULTS The cell surface and mesenchymal stem cell marker expression patterns, multipotential capability, and extent of in vivo cartilage formation did not differ significantly between pASCs and pSSCs. CONCLUSIONS AND CLINICAL RELEVANCE Results suggested that pSSCs may be a viable alternative to pASCs as a source of progenitor cells for tissue engineering in regenerative medicine. [ABSTRACT FROM AUTHOR]

Objective: To assess the effects of transdermal flunixin administration on serum prostaglandin E2 (PGE2) and cortisol concentrations in piglets undergoing castration., Animals: 104 litters with at least 4 male piglets/litter., Procedures: Litters were randomly assigned to 1 of 4 treatments: transdermal flunixin (3.33 mg/kg) administration followed by surgical castration (CF; n = 28), transdermal flunixin administration followed by sham castration (SF; n = 26), application of physiologic saline solution followed by sham castration (S; n = 26), and application of physiologic saline solution followed by surgical castration (C; n = 24). Blood samples were collected 24 hours before and 1, 4, and 25 hours after castration or sham castration., Results: Serum PGE2 concentrations for piglets in the C and CF groups did not differ at any time. Piglets in the S group tended to have higher serum PGE2 concentrations 1 hour after sham castration compared with piglets in the SF group. One hour after the procedure, piglets that underwent castration had higher serum cortisol concentrations than did piglets that underwent sham castration. Piglets in the CF group had higher serum cortisol concentrations than did piglets in the SF group 4 hours after the procedure, but serum cortisol concentrations did not differ between the C and S groups., Clinical Relevance: Further studies are needed to explore dosing regimens, including effective doses and administration frequencies, and the pharmacokinetics of flunixin following transdermal administration in piglets undergoing castration.

Objective--To characterize the kinetics of interleukin (IL)-4, IL-5, and IL-13 secretion in peripheral blood and lymph node mononuclear cells isolated from porcine circovirus type 2 (PCV2)-vaccinated pigs after cells were challenged with PCV2 open reading frame 2 antigen. Animals--10 pigs. Procedures--5 pigs were vaccinated with a PCV2 vaccine and received a booster dose 3 weeks later. They were kept together with a similar group of 5 nonvaccinated pigs that served as controls. One week after the second vaccination, peripheral blood mononuclear cells (PBMCs) and excised retropharyngeal lymph node mononuclear cells (LNMCs) were isolated and cultured. Cells were then challenged by exposure to PCV2 open reading frame 2 and evaluated at 2, 12, 24, and 48 hours to determine the expression of IL-4, IL-5, and IL-13 via quantitative PCR assay. Changes in gene expression were analyzed relative to the results from analysis of the sample at 0 hours (calibrator). Results--All ILs were upregulated differently in LNMCs and PBMCs from vaccinated pigs. Lymph node mononuclear cells from vaccinated animals produced significantly more IL-4 mRNA than did PBMCs at 2, 12, and 48 hours (relative change: 2.8 vs -3.6, 13.0 vs 3.6, and 9.8 vs 1.8, respectively) and more IL-5 mRNA at 2, 12, 24, and 48 hours (relative change: 1.2 vs -4.8, 2.2 vs 0.2, 3.2 vs -1.9, and 4.0 vs -3.6, respectively). Interleukin-13 mRNA reached its highest concentration at 24 hours but was 11.9-fold higher in PBMCs than in LNMCs. Conclusions and Clinical Relevance--Results supported the importance of IL-4, IL-5, and IL-13 in pigs, suggesting that PBMCs and LNMCs express cytokines in a tissue-specific manner. [ABSTRACT FROM AUTHOR]

Objective--To measure the relationship between gross lesions in swine carcasses observed at a processing plant and Salmonella contamination and to determine whether nonexpert assessments of lesion status would correspond with swine pathologists' judgments. Animals--Carcasses of 202 conventionally raised and 156 antimicrobial-free pigs in a Midwestern US processing plant examined from December 2005 to January 2006. Procedures--4 replicates were conducted. For each, freshly eviscerated carcasses were identified as having or lacking visceral adhesions by a nonexpert evaluator and digital carcass photographs were obtained. Swab specimens were obtained from carcasses before the final rinse stage of processing, and bacterial culture for Salmonella spp and Enterococus spp was performed. Subsequently, carcass photographs were numerically scored for lesion severity by 3 veterinary pathologists. Results were used to test the ability of lesion detection to predict bacterial contamination of carcasses and the agreement between judgments of the inexperienced and experienced assessors. Results--The probability of Salmonella contamination in carcasses with lesions identified at the abattoir was 90% higher than that in carcasses lacking lesions, after controlling for replicate identity and antimicrobial use. The receiver operating characteristic curve and Cohen κ indicated close agreement between lesion detection at the abattoir and by the 3 pathologists. Conclusions and Clinical Relevance--Findings indicated the presence of lesions could be used to predict Saimonefla contamination of swine carcasses and that a nonexpert processing-line assessment of lesions could be used to discriminate between healthy and chronically ill swine before their entry into the human food supply. [ABSTRACT FROM AUTHOR]

Objective--To determine effects of 2 doses of caffeine on metabolic variables in neonatal pigs with peripartum asphyxia. Animals--180 neonatal pigs. Procedures--Neonatal pigs were assigned to 2 groups (groups P and F) on the basis of results for a vitality scale (passed or failed, respectively). Within each group, there were 3 subgroups of 30 pigs each. Within each group, the 3 subgroups received a placebo that consisted of an empty gelatin capsule, a gelatin capsule that contained 20 mg of caffeine, and a gelatin capsule that contained 35 mg of caffeine, respectively; all capsules were administered orally (0 hours). Blood samples were collected immediately before and 24 hours after capsule administration. Results--Pigs in groups P and F that received 20 or 35 mg of caffeine had significant increases in triglyceride concentrations. All pigs in groups P and F had a significant decrease in lactate concentrations, although the placebo-treated pigs in group F had larger decreases than did the group F pigs treated with 20 or 35 mg of caffeine. Glucose concentrations increased significantly in group F pigs treated with 20 or 35 mg of caffeine (30% and 50%, respectively), whereas glucose concentrations remained unchanged in group P pigs. In pigs treated with 35 mg of caffeine, the final weight obtained for group F was approximately 8% lower than that obtained for group R Conclusions and Clinical Relevance--Administering caffeine immediately after birth to neonatal pigs with severe oxygen restriction resulted in significant improvements in metabolic variables. [ABSTRACT FROM AUTHOR]

Objective--To assess in pigs the pathogenicity and virulence of 3 strains of Salmonella spp capable of causing atypical salmonellosis in cattle. Animals--36 Holstein calves and 72 pigs experimentally infected with Salmonella spp. Procedures--Representative Salmonella strains associated with 3 new disease phenotypes (protozoa-mediated hypervirulence, multisystemic cytopathicity, and encephalopathy) that have been characterized in cattle during the past 10 years were orally inoculated into pigs. Clinical manifestations were compared with those observed in cattle. Samples were collected from various tissues, and the presence of Salmonella organisms was assessed qualitatively and quantitatively by use of Salmonella-selective media. Results--Of the 3 unique Salmonella disease phenotypes observed in cattle, only protozoa-mediated hypervirulence was observed in pigs. Hypervirulence was related to a more rapid onset of disease and higher pathogen burden in pigs than in cattle. This phenotype was observed in pigs inoculated with multiresistant Salmonella enterica serotypes Typhirnurium or Choleraesuis bearing the Salmonella genomic island 1 (SGI1) integron. Conclusions and Clinical Relevance--Salmonella hypervirulence was identified in pigs inoculated with SGI1-bearing strains exposed to free-living protozoa. Additionally, an SGI1-bearing strain of Salmonella Choleraesuis was detected that resulted in augmented virulence in pigs. Therefore, it appeared that protozoa-associated salmonellosis was analogous in pigs and cattle. Salmonella-mediated encephalopathy and multisystemic cytopathicity did not appear to be relevant diseases in pigs. [ABSTRACT FROM AUTHOR]

Objective--To evaluate changes in antimicrobial consumption and productivity by Danish swine farms during 1992 to 2008. Sample Population--All Danish swine farms for antimicrobial consumption data and a representative sample of Danish swine herds for productivity data. Procedures--Antimicrobial consumption by Danish swine farms from 1992 to 2008 was determined and evaluated in light of policies to regulate antimicrobial consumption, changes in disease patterns, and productivity data. Trend analyses of productivity data were conducted before and after a ban on use of antimicrobial growth promoters (AGPs). Results--Antimicrobial consumption peaked at 100 mg/kg of swine produced in 1992, decreased to 31 mg/kg in 1999, and increased to 49 mg/kg in 2008. Key factors for changes were regulations banning subtherapeutic use of antimicrobials and veterinary profits from the prescription and sale of antimicrobials in 1994 and termination of AGP use by January 2000. Pig production increased from 18.4 to 271 million pigs, and the mean number of pigs per sow per year raised for slaughter increased from 21 in 1992 to 25 in 2007. Average daily gain for weaning (< 35 kg) and finishing (> 35 kg) pigs was higher in 2008 than in 1992, but mortality rates for weaning and finishing pigs were similar in 1992 and 2008. Conclusions and Clinical Relevance--From 1992 to 2008, antimicrobial consumption per kilogram of pig produced in Denmark decreased by > 50%. Furthermore, there was improvement in productivity, suggesting that long-term swine productivity was not negatively impacted by a ban on AGP use. [ABSTRACT FROM AUTHOR]

Objective--To investigate effects of bacteria-mediated inflammation on hepatic drug metabolizing enzymes (DMEs) in swine via a lipopolysaccharide (LPS) challenge technique. Animals--22 Poland China-Landrace crossbred barrows. Procedures--In experiment 1, 10 market-weight swine were treated with LPS (20 pg/kg, IV [n = 5 swine]) or sham-injected (5) 24 hours before slaughter. In experiment 2, 12 growing and finishing swine were treated with LPS at 2 or 20 µg/kg, IV (n = 3 swine/age group/treatment) 24 hours before slaughter. Hepatic DMEs, cytochrome P450 (CYP) isoforms, and CYP-mediated reactions were measured. Results--In experiment 1, LPS administered at 20 µg/kg decreased most hepatic DME components and inhibited enzymatic activities. In experiment 2, both doses reduced protein content in subcellular fractions and inhibited some DME-and CYP-mediated activities. In growing and finishing swine, CYP2A and CYP2B isoforms were not detected after treatment with LPS; the CYP1A2 isoform was eliminated in growing but not in finishing swine. Lipopolysaccharide also reduced CYP2D6 content in growing and finishing swine but increased CYP2E content. Lipopolysaccharide had no effect on swine CYP2C11, CYP2C13, or CYP3A content. The CYP2B-mediated 7-pentoxyresorufin O-dealkylase activity in growing and finishing swine was totally eliminated, and 7-ethoxyresorufin (indicating CYP1A activity) and aniline (mediated by CYP2E) metabolism was decreased. Conclusions and Clinical Relevance--Effect of LPS treatment on swine CYPs appeared to be isoform specific; age-related metabolic status of the swine and the LPS dose modified this effect. Lipopolysaccharide-induced inflammation may affect metabolism of drugs and xenobiotics in swine. (Am J Vet Res 2010;71:342-348) [ABSTRACT FROM AUTHOR]

Objective--To determine whether commercial Mycoplasma hyopneumoniae bacterins sold for use in swine contain porcine torque teno virus (TTV). Sample Population--22 commercially available M hyopneumoniae bacterins. Procedures--Direct and nested PCR assays for genogroup-specific TTV DNAs were performed on serials of M hyopneumoniae bacterins by use of published and custom-designed primer pairs at 3 laboratories in North America and Europe. Results--Of the 22 bacterins tested by use of direct and nested PCR assays, 7 of 9 from the United States, 2 of 5 from Canada, and 4 of 8 from Europe contained genogroup 1- and genogroup 2-TTV DNAs. In some bacterins, the TTV DNAs were readily detected by use of direct PCR assays. Conclusions and Clinical Relevance--Analysis of these data indicated that many of the commercially available M hyopneumoniae bacterins were contaminated with TTV DNA. It is possible that some of these bacterins could inadvertently transmit porcine TTV infection to TTV-naïve swine. [ABSTRACT FROM AUTHOR]

Objective--To develop a whole-kidney computed tomography (CT) technique that would allow 3-point Patlak plot determination of glomular filtration rate (GFR) and assess the correlation of GFR determined via CT (CT-GFR) with GFR determined via renal plasma clearance of inulin (Inu-GFR)in pigs. Animals--6 healthy anesthetized pigs. Procedures--Each pig underwent 3-phase whole-kidney helical CT (arterial, early, and late parenchymal phases) before and after contrast medium administration. After contrast medium administration, corrected Hounsfield unit values were determined for each kidney and the aorta. A 3-point Patlak plot for each kidney was generated, and plasma clearance per unit volume was multiplied by renal volume to obtain whole-animal CT-GFR. Correlations of mean Inu-GFR for the left and right kidneys (and combined)total] values) with the corresponding CT-GFRs were assessed via linear regression and Bland-Altman analyses. Results--Left kidney, right kidney, and total CT-GFRs were good predictors of the respective Inu-GFR values (r² = 92.3%, r² = 85.5%, and r² = 93.7%, respectively). For the left kidney, no significant bias between Inu-GFR and CT-GFR was detected. Right kidney and total CT-GFRs underestimated the corresponding Inu-GFRs (mean underestimation, -8.4 mL·min-1 and-12.6 mL·min-1 respectively). Conclusions and Clinical Relevance--Three-phase whole-kidney CT with Patlak plot analysis of GFR may underestimate right kidney and total Inu-GFRs in pigs. The Patlak plot generated may be sensitive to nonlinearity caused by temporal variation in GFR. Nonetheless, the 3-phase CT approach offers some practical advantages for simultaneous evaluation of renal morphology and measurement of GFR. [ABSTRACT FROM AUTHOR]

Objective--To determine the enzymatic and hormonal responses, heat shock protein 70 (Hsp70) production, and Hsp70 mRNA expression in heart and kidney tissues of transport-stressed pigs. Animals--24 pigs (mean weight, 20 ± 1 kg). Procedures--Pigs were randomly placed into groups of 12 each. One group was transported for 2 hours. The other group was kept under normal conditions and used as control pigs. Sera were used to detect triiodothyronine, thyroxine, and cortisol concentrations and alanine aminotransferase, aspartate aminotransferase, and creatine kinase activities. The heart and kidneys of anesthetized pigs were harvested and frozen in liquid nitrogen for quantification of Hsp70 and Hsp70 mRNA. Results--No significant differences were detected in serum alanine aminotransferase activity and triiodothyronine and cortisol concentrations between groups; however, the serum creatine kinase and aspartate aminotransferase activities and thyroxine concentrations were higher in transported pigs. Densitometric readings of western blots revealed that the amount of Hsp70 in heart and kidney tissues was significantly higher in transported pigs, compared with control pigs. Results of fluorescence quantitative real-time PCR assay revealed that the Hsp70 mRNA transcription in heart tissue, but not kidney tissue, was significantly higher in transported pigs, compared with control pigs. Conclusions and Clinical Relevance--Transportation imposed a severe stress on pigs that was manifested as increased serum activities of aspartate aminotransferase and creatine kinase and increased amounts of Hsp70 and Hsp70 mRNA expression in heart and kidney tissues. Changes in serum enzyme activities were related to the tissue damage of transport-stressed pigs. [ABSTRACT FROM AUTHOR]

Objective--To determine whether the addition of chromic oxide (Cr2O3) to creep feed could be used as a visual marker in feces for selection of creep feed-eating suckling pigs. Animals--20 suckling pigs. Procedures--Via syringe, 5 pigs (2 to 3 days old on day 0; 1 pig/treatment) from each of 4 litters received oral administrations of 10, 20, 30, or 40 g of creep feed containing 10 g of Cr2O3·kg-1 on each of 2 consecutive days (days 20 and 21) or 30 g of creep feed containing 10 g of Cr2O3·kg-1 on day 20 and 30 g of Cr2O3-free creep feed on day 21. On days 21 through 24, 6 fecal samples were collected from each pig at regular intervals between 8:00 AM and 6:00 PM. Green-colored feces were considered indicative of creep feed consumption (eaters). Data analyses were based on single and multiple fecal samples. Results--On day 22, evaluation of 1 fecal sample/pig and multiple fecal samples per pig resulted in identification of as many as 40% and only 15% of the feed-treated pigs wrongly as noneaters, respectively. Repeated sampling over multiple days would identify 99% of eaters accurately. Pigs erroneously identified as noneaters were those administered either low amounts of Cr2O3-supplemented creep feed for 2 days or Cr2O3-supplemented creep feed on only 1 day. Conclusions and Clinical Relevance--Data suggest that addition of Cr2O3 to creep feed enables selection of individual creep feed-eating suckling pigs via examination of feces, provided that repeated fecal samples are evaluated. [ABSTRACT FROM AUTHOR]

Objective--To determine the prevalence of antibodies against a swine-origin Helieobacter pylori-like organism (HPLO) and H pylon in conventionally reared swine. Animals--640 conventionally reared swine of various ages from 16 high-health farms in Canada, 20 sows from Ohio, and 35 gnotobiotic swine. Procedures--Blood was collected from the cranial vena cava. Sera were collected and tested via ELISA for antibodies against antigen prepared from a swine-origin HPLO and human Hpyloristrain 26695, Results--Antibodies reactive with a swine HPLO, H pylori, or both were detected in 483 of 640 swine from all 16 farms in western Canada. Seroprevalence varied with age and was low (5.6%) in suckling (≤ 4-week-old) swine and increasingly high in swine ranging from > 4 weeks old to adulthood. Conclusions and Clinical Relevance--Findings suggested that colonization by a swine-origin HPLO, H pylori, or both and resultant seroconversion, like that of H pylon infection in humans, were common in commercial swine operations, Furthermore, data indicated that gastric infection was acquired at an early age. The relationships to gastric colonization by HPLOs and clinical manifestations of disease such as gastritis and gastroesophageal ulceration remain to be determined. [ABSTRACT FROM AUTHOR]

Objective--To determine the immunogenicity and efficacy of Brucella abortus strain RB51 (SRB51) as a vaccine in domestic pigs. Animals--Sixty-eight 6-week-old crossbred domestic pigs and twenty-four 4-month-old gilts. Procedures--In experiment 1, pigs were vaccinated IM (n = 51) with 2 x 1010 CFUs of SRB51 or sham inoculated (17). Periodic blood samples were obtained to perform blood cultures, serologic evaluations, and cell-mediated immunity assays. Necropsies were performed at selected times between weeks 1 and 23 after vaccination to determine vaccine clearance. In experiment 2, gilts were similarly vaccinated (n = 18) or sham inoculated (8) and similar samples were obtained after vaccination. Gilts were bred and challenged conjunctivally with 5.0 x 107 CFUs of virulent Brucella suis strain 3B. Necropsies were performed on gilts and on fetuses or neonates after abortion or parturition, respectively. Bacterial cultures and serologic evaluations were performed on samples obtained at necropsy to determine vaccine efficacy. Results--Humoral and cell-mediated immune responses did not differ between vaccinates and controls. After vaccination, SRB51 was not isolated from blood cultures of either group and was isolated from lymphoid tissues of 3 pigs at 2 weeks (n = 2) and 4 weeks (1) after vaccination. No differences were found in isolation of B suis or in seroconversion between vaccinated and control gilts and between their neonates or aborted fetuses. Conclusions and Clinical Relevance--Parenteral vaccination with SRB51 does not induce humoral or cell mediated immune responses. Vaccination with SRB51 did not protect gilts or their neonates and fetuses from virulent challenge with B suis. [ABSTRACT FROM AUTHOR]

Objective--To determine the susceptibility of strains of Pasteurella multocida subsp multocida isolated from lung specimens of pigs with pneumonia to 20 antimicrobials and to evaluate the emergence of resistance to those antimicrobials in Spain during the past 2 decades. Sample Population--63 isolates recovered from 1987 to 1988 and 132 isolates recovered from 2003 to 2004. Procedure--A broth microdilution method was used to determine minimal inhibitory concentration (MIC) range and values for MIC50 and MIC90. Resistance of a strain to an antimicrobial agent was determined by use of the breakpoint value when available. Results--Isolates were generally susceptible to penicillin, ampicillin, ceftiofur, gentamicin, apramycin, neomycin, spectinomycin, chlortetracycline, erythromycin, tilmicosin, enrofloxacin, and florfenicol, and most isolates were resistant to clindamycin, tylosin tartrate, and tiamulin regardless of the time period. A substantial increase in resistance to sulfachlorpiridazine, sulfadimethoxine, sulfathiazole, and trimethoprim-sulfamethoxazole was observed, and a minor increase in resistance to oxytetracycline was also detected. Several multiresistance patterns were observed, most frequently among isolates recovered in the 2003 to 2004 interval. Conclusions and Clinical Relevance--Ceftiofur, florfenicol, and enrofloxacin are recommended for treatment of infections caused by P multocida subsp multocida in Spain. Increased frequency of resistance to oxytetracycline and sulfonamide drugs may be a contraindication for their use. [ABSTRACT FROM AUTHOR]

Objective--To evaluate the influences of animal age, bacterial coinfection, and porcine reproductive and respiratory syndrome virus (PRRSV) isolate pathogenicity on virus concentration in pigs. Animals--Twenty-one 2-month-old pigs and eighteen 6-month-old pigs. Procedure--Pigs were grouped according to age and infected with mildly virulent or virulent isolates of PRRSV. The role of concurrent bacterial infection was assessed by infecting selected pigs with Mycoplasma hyopneumoniae 21 days prior to inoculation with PRRSV. On alternating days, blood and swab specimens of nasal secretions and oropharyngeal secretions were collected. On day 21 after inoculation with PRRSV, selected tissues were harvested. Concentrations of PRRSV were determined by use of quantitative real-time PCR and expressed in units of TCID50 per milliliter (sera and swab specimens) or TCID50 per gram (tissue specimens). Results--Concentrations of virus were higher in blood and tonsils of pigs infected with virulent PRRSV. Pigs infected with virulent PRRSV and M hyopneumoniae had significantly higher concentrations of viral RNA in lymphoid and tonsillar tissue. Coinfection with M hyopneumoniae resulted in a higher viral load in oropharyngeal swab specimens and blood samples, independent of virulence of the PRRSV isolate. Two-month-old pigs had significantly higher viral loads in lymph nodes, lungs, and tracheal swab specimens than did 6-month-old pigs, independent of virulence of the PRRSV isolate. Conclusions and Clinical Relevance--Multiple factors affect PRRSV concentration in pigs, including pathogenicity of the PRRSV isolate, age, and concurrent infection with M hyopneumoniae. [ABSTRACT FROM AUTHOR]

Objective--To evaluate the safety and efficacy of a human adenovirus-5 vaccine for protecting weaned pigs against swine influenza virus subtype H3N2 infection when administered via 2 injection methods. Animals--76 pigs. Procedure--6 groups of weaned pigs received a 10-fold serial dilution of recombinant adenovirus expressing H3 hemagglutinin and a constant amount of recombinant adenovirus expressing nucleoprotein, either via a needle-free injection device or by traditional IM injection. In each group of 10 pigs, 1 served as a nonvaccinated contact pig to monitor whether there was spread of vaccinial virus from pig to pig. Vaccinated pigs and nonvaccinated controls were challenged or sham-inoculated 5 weeks later. After challenge, pigs were observed for clinical signs and nasal secretions were tested for virus. On day 5 after challenge, pigs were euthanatized; lungs were examined for gross lesions, and bronchoalveolar lavage specimens were tested for virus replication. Results--A hemagglutination inhibition (HI) antibody response was elicited in a dose-dependent manner. Traditional IM administered vaccination induced consistently higher HI antibody responses than vaccination via needle-free injection, but the differences were not significant. Likewise, traditional IM administration was superior at reducing nasal virus shedding except at the highest dose, at which both methods blocked virus replication. The severity of lung lesions was reduced in a dose-dependent manner by both vaccination methods. Sentinel pigs did not seroconvert. Conclusions and Clinical Relevance--The human adenovirus-5 vaccine at high doses prevented nasal virus shedding after challenge exposure with both methods of administration, The replication-defective vaccine virus was not transmitted to sentinel pigs. [ABSTRACT FROM AUTHOR]

Objective--To develop a flow-limited, physiologic-based pharmacokinetic model for use in estimating concentrations of sulfamethazine after IV administration to swine. Sample Population--4 published studies provided physiologic values for organ weights, blood flows, clearance, and tissue-to-blood partition coefficients, and 3 published studies provided data on plasma and other tissue compartments for model validation. Procedure--For the parent compound, the model included compartments for blood, adipose, muscle, liver, and kidney tissue with an extra compartment representing the remaining carcass. Compartments for the N-acetyl metabolite included the liver and the remaining body. The model was created and optimized by use of computer software. Sensitivity analysis was completed to evaluate the importance of each constant on the whole model. The model was validated and used to estimate a withhold interval after an IV injection at a dose of 50 mg/kg. The withhold interval was compared to the interval estimated by the Food Animal Residue Avoidance Databank (FARAD). Results--Specific tissue correlations for plasma, adipose, muscle, kidney, and liver tissue compartments were 0.93, 0.86, 0.99, 0.94, and 0.98, respectively. The model typically overpredicted concentrations at early time points but had excellent accuracy at later time points. The withhold interval estimated by use of the model was 120 hours, compared with 100 hours estimated by FARAD. Conclusions and Clinical Relevance--Use of this model enabled accurate prediction of sulfamethazine pharmacokinetics in swine and has applications for food safety and prediction of drug residues in edible tissues. [ABSTRACT FROM AUTHOR]

Objective--To determine whether a Helicobacter sp similar to Helicobacter pylori in the stomachs of humans could be isolated from the stomachs of pigs. Animals--4 young conventionally reared and 21 gnotobiotic pigs. Procedure--Gastric mucosal homogenates (10% wt/vol) from 4 young conventionally reared pigs were cultured on Skirrow medium under microaerophilic conditions to assess the presence of Helicobacter spp. Colonies with morphologic features compatible with Helicobacter organisms were selected, tested for urease activity, and subpassaged on Skirrow medium. Isolates were examined via SDS-PAGE electrophoresis and reciprocal western blot analyses involving convalescent sera from monoinfected gnotobiotic pigs. Results--Urease- and catalase-positive, gram-negative, microaerophilic, small, curved rod bacteria were isolated from the gastric mucosa of young healthy pigs. The first isolate (2662) was structurally and immunologically closely related to H pylori isolated from humans. The second isolate (1268) displayed an SDS-PAGE profile dissimilar to that of H pylori and isolate 2662, yet it shared limited immunologic cross-reactivity with these microbes. Conclusions and Clinical Relevance--Findings of this study indicate that development of gastric mucosal ulcers and ulceration of the nonglandular pars esophagea in pigs may be associated with gastric colonization by swine-origin Helicobacter spp, which are similar to H pylori isolated from humans. [ABSTRACT FROM AUTHOR]

Objective--To determine whether 2 isolates of recently isolated swine-origin Helicobacter pylori-like bacteria are pathogenic in pigs and compare the signs of gastric disease induced by these isolates with those detected in H pylori- and Helicobacter heilmannii-infected pigs. Animals--36 neonatal gnotobiotic pigs. Procedure--Groups of separately housed pigs were inoculated orally with swine-origin Helicobacter-like isolates 2662 or 1268, H pylori (human gastric pathogen), or a gastric homogenate from gnotobiotic swine containing H heilmannii. Noninoculated pigs were used as control animals. Clinical signs and development of homologous and heterologous antibodies against Helicobacter organisms were assessed. After euthanasia, gastric tissues were examined grossly and microscopically; Helicobacter organisms were detected by use of Warthin-Starry and immunohistochemical stains. Results--Both porcine Helicobacter-like isolates colonized the stomachs of swine. Isolate 2662 was highly pathogenic; in 13 isolate 2662-inoculated pigs, gastroesophageal ulcerations developed in 9 and ulceration of the gastric glandular mucosa was detected in 5. Histologically, inflammatory gastritis consisting of multifocal to diffuse lymphocytic and plasmacytic cellular infiltrates and lymphoid follicle formation in the gastric lamina propria accompanied bacterial colonization of the gastric compartment. In contrast, H heilmannii was minimally pathogenic in that only modest inflammatory cell infiltrates were seen. Gastroesophageal or mucosal ulcers were not evident in pigs inoculated with H heilmannii. Conclusions and Clinical Relevance--These data indicate that swine-origin H pylori-like bacteria can be pathogenic in pigs and suggest that porcine gastric disease may be mediated, in part, by colonization of the stomach by swine-origin H pylori-like bacteria. [ABSTRACT FROM AUTHOR]

Objective--To determine whether flies can acquire porcine reproductive and respiratory syndrome virus (PRRSV) and disperse the virus throughout a designated area. Animals--60 four-month-old pigs. Procedure--On day 0, 28 of 60 pigs were inoculated with PRRSV MN 30-100 (index variant). On the same day, 100,000 pupae of ochre-eyed houseflies and 100,000 pupae of red-eyed (wild-type) houseflies were placed in the swine facility for a release-recapture study. Flies were recaptured at 2 locations within the swine facility, 6 locations immediately outside the facility, and 30 locations 0.4, 0.8, 1.3, 1.7, 1.9, and 2.3 km from the facility. Traps were emptied on days 2, 7, 8, 10, and 14. Samples derived from flies were tested by use of a polymerase chain reaction assay, virus DNA was sequenced, and viruses were tested for infectivity by means of a swine bioassay. Results--PRRSV RNA homologous to the index PRRSV was detected in trapped flies collected inside and immediately outside the facility and from 9 of 48 samples collected at 0.4 km, 8 of 24 samples collected at 0.8 km, 5 of 24 samples collected at 1.3 km, and 3 of 84 samples collected at ≥ 1.7 km from the facility. Two samples collected at 0.8 km contained genetically diverse variants of PRRSV. Swine bioassays revealed the virus in flies was infectious. Conclusions and Clinical Relevance--Flies appeared to become contaminated with PRRSV from infected pigs and transported the virus ≥ 1.7 km. Fly-born transmission may explain how PRRSV is seasonally transported between farms. [ABSTRACT FROM AUTHOR]

Objective--To determine whether pigs can be infected with strains of vesicular stomatitis virus New Jersey (VSV-NJ) and vesicular stomatitis virus Indiana (VSV-I) isolated during recent vesicular stomatitis outbreaks that primarily involved horses in the western United States and determine the potential for these viruses to be transmitted by contact. Animals--128 pigs. Procedure--Pigs were challenged with VSV-NJ or VSV-I from the 1995 and 1997 outbreaks of vesicular stomatitis in the western United States, respectively, or with VSV-NJ (OS) associated with vesicular stomatitis in feral pigs on Ossabaw Island, Ga. Pigs (3/group) were inoculated with each virus via 3 routes and evaluated for viral shedding, seroconversion, and the development of vesicular lesions. In another experiment, the potential for contact transmission of each virus from experimentally infected to naïve pigs was evaluated. Results--Infection of pigs was achieved for all 3 viruses as determined by virus isolation and detection of seroconversion. In inoculated pigs, all 3 viruses were isolated from multiple swab samples at concentrations sufficient to infect other pigs. However, compared with results obtained with the 2 VSV-NJ strains, viral titers associated with VSV-I were low and the duration of virus shedding was reduced. Results from the contact transmission trials were consistent with these results; virus transmission was detected most frequently with the VSV-NJ strains. Conclusions and Clinical Relevance--Pigs can be infected with VSV-NJ and VSV-I. Differences in the extent of viral shedding and potential for contact transmission were apparent between serotypes but not between the VSV-NJ strains investigated. [ABSTRACT FROM AUTHOR]

Objective--To measure the effect of Escherichia coli subtype O149:F4-induced diarrhea on the pharmacokinetics of orally administered amoxicillin in affected piglets relative to that of uninfected piglets. Animals--22 healthy 4-week-old recently weaned Danish crossbred piglets. Procedure--12 piglets were orally inoculated through gastric intubation with 109 CFUs of an E coli O149:F4 strain and responded by developing diarrhea 12 to 16 hours later. Piglets were dosed with amoxicillin trihydrate solution (20 mg/kg) by gastric intubation. A control group of 10 age-matched piglets without signs of diarrhea was dosed similarly. Blood samples were obtained before amoxicillin administration and at 0.5, 1, 1.5, 2, 3, 6, 12, and 24 hours after amoxicillin administration. The plasma concentration of amoxicillin was analyzed by high-performance liquid chromatography. Results--A significant 39% decrease in the area under the plasma concentration versus time curve of amoxicillin was observed in piglets with diarrhea relative to that of control piglets. The maximum plasma concentration (Cmax) was significantly (52%) lower in piglets with diarrhea, compared with control piglets, while the elimination rate constant, time to reach Cmax, and elimination half-life were unchanged. Conclusions and Clinical Relevance--Escherichia coli-induced diarrhea may decrease systemic bioavailability of amoxicillin. Escherichia coli bacteria attach to the intestinal epithelial cells. Because it is assumed that the concentration of the antimicrobial at the site of infection reflects the systemic concentration, higher doses of amoxicillin in the treatment of piglets with E coli O149:F4-induced diarrhea may be appropriate. [ABSTRACT FROM AUTHOR]

Objective--To evaluate bispectral index (BIS), spectral edge frequency 95% (SEF), and median frequency (MED)in relation to a visual analogue scale (VAS) as indicators of anesthetic depth for various concentrations of sevoflurane and isoflurane in pigs. Animals--32 pigs. Procedure--Pigs were randomly allocated to 8 groups (4 pigs/group). An electroencephalogram (EEG) was recorded in each conscious pig. Pigs were then anesthetized by use of sevoflurane (n = 16) or isoflurane (16). Agents were administered in oxygen at minimum alveolar concentrations (MACs) of 1, 1.25, 1.5, and 1.75 MAC in a randomized order. End-tidal sevoflurane and isoflurane concentrations were maintained for 30 minutes, after which an EEG was recorded for 5 minutes; BIS, SEF, and MED were then calculated. Anesthetic depth was evaluated by use of the VAS. Cardiovascular and EEG responses to nociceptive stimuli were evaluated for each anesthetic agent. Results--BIS decreased significantly for the various concentrations of each anesthetic. At equivalent MACs, BIS values were significantly higher during sevoflurane-induced anesthesia than during isoflurane-induced anesthesia. Values of MED and SEF decreased significantly from basal values to 1 MAC of sevoflurane and isoflurane. For both agents, there was good correlation between VAS scores and BIS values and between VAS scores and SEF values. Conclusions and Clinical Relevance--BIS was useful for predicting changes in anesthetic depth at clinical dosages of inhalant anesthetics. Values of BIS, SEF, and MED were significantly higher during anesthesia induced by administration of sevoflurane than during anesthesia induced by administration of isoflurance at... [ABSTRACT FROM AUTHOR]

The article reports that an influenza virus circulating among Chinese pigs has the genetic potential of a pandemic virus in humans, according to a report published in late June 2020 in the journal "Proceedings of the National Academy of Sciences."