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Swine dysentery is a severe enteric disease in pigs, which is characterized by bloody to mucoid diarrhea and associated with reduced growth performance and variable mortality. This disease is most often observed in grower–finisher pigs, wherein susceptible pigs develop a significant mucohemorrhagic typhlocolitis following infection with strongly hemolytic spirochetes of the genus Brachyspira. While swine dysentery is endemic in many parts of the world, the disease had essentially disappeared in much of the United States by the mid-1990s as a result of industry consolidation and effective treatment, control, and elimination methods. However, since 2007, there has been a reported increase in laboratory diagnosis of swine dysentery in parts of North America along with the detection of novel pathogenic Brachyspira spp worldwide. Accordingly, there has been a renewed interest in swine dysentery and Brachyspira spp infections in pigs, particularly in areas where the disease was previously eliminated. This review provides an overview of knowledge on the etiology, pathogenesis, and diagnosis of swine dysentery, with insights into risk factors and control. [ABSTRACT FROM AUTHOR]

Porcine epidemic diarrhea virus (PEDV) was first recognized in North America in April 2013 and has since caused devastating disease. The objective of this study was to characterize disease and viral detection associated with an original North American PEDV isolate inoculated in neonatal piglets. Thirty-six 1-day-old cesarean-derived and colostrum-deprived piglets were randomly assigned to the control (n = 16) or challenged group (n = 20); the latter were orogastrically inoculated with 1 ml of US/Iowa/18984/2013 PEDV isolate titered at 1 × 103 plaque-forming units per milliliter. Rectal swabs were collected from all piglets prior to inoculation and every 12 hours postinoculation (hpi) thereafter, with 4 control and 5 challenged piglets euthanized at 12, 24, 48, and 72 hpi. One piglet had a positive real-time quantitative polymerase chain reaction test on rectal swab at 12 hpi, and all remaining piglets were positive thereafter, with highest viral quantities detected at 24 and 36 hpi. Diarrhea was evident in 30% and 100% of challenged piglets at 18 and 24 hpi, respectively. Viral antigen was detected in enterocytes by immunohistochemistry in the duodenum and ileum of piglets euthanized at 12 hpi and was apparent throughout the small intestine of all piglets thereafter, with villus height:crypt depth ratios consistently below 4:1. Viremia was confirmed in 18 of 20 pigs at euthanasia. Clinical disease was severe and developed rapidly following infection with an original North American PEDV isolate, with lesions, viremia, and antigen detection possible by 12 hpi. [ABSTRACT FROM AUTHOR]

Melanosis coli is a dark discoloration of the colon due to accumulation of pigment-laden macrophages in the lamina propria. Three case submissions were received where rectal discoloration was reported at slaughter in pigs from separate production systems and melanosis coli was confirmed microscopically. Tissues from affected and unaffected cohort pigs were evaluated for evidence of oxidative damage using immunohistochemical staining for 3-nitrotyrosine, 4-hyroxynonenol, and malondialdehyde. Affected colons had significantly greater immunolabeling for all 3 target compounds than unaffected colons (P ≤ .001, all analyses). Hepatic vitamin E levels were low in both affected and unaffected pigs, and there was a trend toward lower values in affected pigs. Given the limited number of slaughter-collected samples available for this investigation, further study is warranted to elucidate the possible association between low vitamin E concentrations and oxidative damage in cases of melanosis coli in pigs. [ABSTRACT FROM AUTHOR]

The article describes the pathologic findings in two cases of feline thymomas with intratumoral amyloid deposition. The first cat is an 11-year-old, spayed female, Himalayan cat while the second cat is 12-year-old, male domestic cat that was euthanized because of neurological signs and behavioral changes. It concluded that the pathologic findings were consistent with amyloid production by the neoplastic epithelial cells.

The article focuses on a study which compared the growth and chemotaxis of IA3902 and a reference strain with the presence of subplacental and placental factors as well as bile and plasma, from pregnant and non-pregnant guinea pigs. The study characterized the spatial distribution of putative growth-promoting factors in various regions of the guinea pig placental unit and evaluated the effects of these potential factors on the growth and chemotaxis of IA3902 and NCTC 11168 in vitro.

The article investigates whether the expression of toll-like receptors (TLR) 2 and 4 will be affected in subplacental trophoblasts following Campylobacter (C.) jejuni infection. The authors explain that TLR2 and TLR4 are cell surface receptors that have roles in pathogen recognition and in the activation of the immune system. They report that based on the study, abortion in guinea pigs after C. jejuni infection results in increased TLR2 expression in subplacental trophoblasts which could mean that TLR2 has a role in C.-induced abortion pathogenesis.

Porcine epidemic diarrhea virus (PEDV) is an Alphacoronavi-rus and was first identified in U. S. pigs in April 2013. It is known to affect the small intestine to produce clinical signs of diarrhea and dehydration and can be fatal in piglets. The objective of this study was to determine the longitudinal effect of PEDV infection on nursery pig growth performance and tissue accretion rates. Fifty Choice Genetics gilts and barrows (BW = 9.92 ± 0.49 kg) naive for PEDV were allotted into 2 treatment groups with equal barrows and gilts distributed among 8 pens per treatment. The treatments were: 1) control (n = 8 pens) and 2) PEDV inoculated (n = 8 pens). At -3 d post inoculation (dpi), a subset of 1 pig per pen was scanned live to determine initial body composition using a dual-energy X-ray (DXA) absorptiometry machine. On 0 dpi, all 25 PEDV pigs were inoculated with 103 TCID50/ml of PEDV via gastric gavage. During 2-14 dpi, 17 pigs per treatment were necropsied to monitor disease progression. On 14 dpi, 8 pigs per treatment remained. Over the 42 d experimental period, PEDV infection and naivety was confirmed via fecal PCR testing. Pen body weights, feed intake, and calculated G:F were recorded on dpi 2, 5,7 and weekly thereafter. At 42 dpi, the same 8 pigs per treatment were DXA scanned again to determine final body composition and tissue accretion rates were calculated. Gain to reach 127 kg market B W was calculated from average BW at 42 dpi. All pigs were allowed free access to a corn-soybean meal diet and water. Treatment and time effects were determined using pen as the experimental unit. There was no difference (P = 0.344) in start BW between treatments. Overall, compared to the control pigs, PEDV reduced ADFI (0.92 verses 0.70 kg, P = 0.044) and tended to reduce ADG (0.74 verses 0.63 kg, P = 0.056). However, overall G:F was not altered (P = 0.625). Pigs inoculated with PEDV had decreased (P < 0.05) whole body accretion (g/d) for fat, lean, and protein compared to control pigs (24%, 20%, and 21% reductions, respectively). Pigs inoculated with PEDV would need to gain 7% more BW (P = 0.014) than control pigs to reach 127 kg market weight. In summary, we have shown that nursery pig exposure to PEDV has a long term negative impact on pig performance and whole body tissue accretion rates. [ABSTRACT FROM AUTHOR]

With the emergence of "Brachyspira hampsonii" associated with swine dysentery in North America, identification of effective treatments and interventions is a pressing need. Denagard® (tiamulin hydrogen fumarate) Liquid Concentrate 12.5% is approved in the United States for treatment of dysentery caused by Brachyspira hyodysenteriae at 0.006% in the water. In this study, the effectiveness of tiamulin in resolving clinical disease, eliminating viable spirochete shedding, and reducing neutrophilic colitis following infection with either "B.?hampsonii" or B.?hyodysenteriae was evaluated. Seventy-eight 7-week-old crossbred pigs were divided into three groups [sham-inoculated (n?=?18), "B.?hampsonii"-inoculated (n?=?30), and B.?hyodysenteriae-inoculated (n?=?30)]. Each inoculum group was divided into three subgroups which received either 0.006% tiamulin, 0.018% tiamulin, or no medication. Both levels of tiamulin resolved clinical disease within 24 h of treatment initiation, eliminated spirochete shedding within 72 h of treatment initiation, and resolved and/or prevented histologic lesions in pigs infected with either Brachyspira spp. [ABSTRACT FROM AUTHOR]

The pig intestinal epithelium can be compromised by pathogens leading to reduced integrity and function. Porcine epidemic diarrhea virus (PEDV), recently detected in North America, exemplifies intestinal epithelial insult. Although several studies have investigated the molecular aspects and host immune response to PEDV, there are little data on the impact of PEDV on pig intestinal physiology. The objective of this study was to investigate the longitudinal impact of PEDV on nursery pig intestinal function and integrity. Fifty recently-weaned, 5-week-old barrows and gilts (BW=9.92±0.49kg) were sorted based on body weight (BW) and sex into two treatments: 1) Control or 2) PEDV inoculated. At 2, 5, 7, and 14days post inoculation (dpi), 4 pigs per treatment were euthanized and jejunum sections collected. PEDV antigen was detected in inoculated pigs by immunohistochemistry in 50% (2/4) at dpi 2, 100% (4/4) at dpi 5, and none at later time points. PEDV-infected pigs had reduced (P<0.05) villus height and decreased transepithelial resistance compared with controls. Total acidic mucins, particularly sialomucin, were reduced in PEDV pigs at dpi 2 and then increased compared with controls at dpi 7 and 14. In addition, PEDV pigs had increased stem cell proliferation (P<0.05) and a numerical increase in DNA fragmentation compared with controls through dpi 7 which coincided with an observed return of digestive function to that of controls. Collectively, these data reveal that PEDV infection results in time-dependent changes not only in intestinal morphology but also barrier integrity and function., (Copyright © 2017 Elsevier B.V. All rights reserved.)

Porcine epidemic diarrhea virus (PEDV) is associated with clinical diarrhea in naïve swine of all ages. This report describes timing of antibody generation and disease progression following infection with a US PEDV isolate by assessing fecal viral shedding, morphometric analysis of intestinal lesions, and magnitude of immunohistochemical staining. Sixty-three, 3-week-old pigs were randomly allocated into control (n=27) and challenged (n=36) groups. Challenged pigs were administered 1 mL of 1 × 10(3) PFU/mL of US/Iowa/18984/2013 PEDV isolate by oro-gastric gavage. Three control and four challenged pigs were necropsied on days post-inoculation (dpi) 1, 2, 3, 4, 7, and weekly thereafter, until study termination on dpi 35. Clinical disease, fecal shedding, body weight, and temperature were monitored during the study period. Diarrhea was observed in challenged pigs beginning for some on dpi 2, affecting a majority of pigs by dpi 6 and subsiding by dpi 10. Average daily gain was significantly lower (P<0.001) for one week post-infection in challenged pigs. PEDV was detected in feces by PCR on dpi 1 and continued in a subset of pigs until dpi 24. PEDV-specific antigen was detected in villous enterocytes of challenged pigs by immunohistochemistry (IHC) on dpi 1, 2, 3, 4, 7, and 14. Microscopic lesions included severe diffuse atrophic enteritis with significantly reduced (P<0.001) villous length observed on dpi 3, 4, and 7. Under the conditions of this study, fecal shedding of PEDV and IHC staining can precede and continue beyond the observation of clinical signs, thus increasing the risk of viral transmission., (Copyright © 2014 Elsevier B.V. All rights reserved.)

Swine dysentery is classically associated with infection by Brachyspira hyodysenteriae, the only current officially recognized Brachyspira sp. that consistently imparts strong beta-hemolysis on blood agar. Recently, several strongly beta-hemolytic Brachyspira have been isolated from swine with clinical dysentery that are not identified as B. hyodysenteriae by PCR including the recently proposed species "Brachyspira hampsonii." In this study, 6-week-old pigs were inoculated with either a clinical isolate of "B. hampsonii" (EB107; n = 10) clade II or a classic strain of B. hyodysenteriae (B204; n = 10) to compare gross and microscopic lesions and alterations in colonic mucin expression in pigs with clinical disease versus controls (n = 6). Gross lesions were similar between infected groups. No histologic difference was observed between infected groups with regard to neutrophilic inflammation, colonic crypt depth, mucosal ulceration, or hemorrhage. Histochemical and immunohistochemical evaluation of the apex of the spiral colon revealed decreased expression of sulphated mucins, decreased expression of MUC4, and increased expression of MUC5AC in diseased pigs compared to controls. No difference was observed between diseased pigs in inoculated groups. This study reveals significant alterations in colonic mucin expression in pigs with acute swine dysentery and further reveals that these and other microscopic changes are similar following infection with "B. hampsonii" clade II or B. hyodysenteriae., (© The Author(s) 2014.)