Risk factors for Salmonella spp in Portuguese breeding pigs using a multilevel analysis

Salmonella is the second most frequent cause of foodborne illness in the European Union (EU), so EU enforced legislation to achieve a reduction in Salmonella prevalence in the swine sector. To set the reduction target each country carried out a baseline survey to estimate Salmonella prevalence. The aim of our study was to identify risk factors for the presence of Salmonella in breeding pigs based on the data of the Baseline Study for Salmonella in Breeding Pigs in Portugal. In total, 1670 pen fecal samples from 167 herds were tested by culture and 170 samples tested positive. Along with the collection of the samples a survey was applied to collect information about the herd management and potential risk factors. Multilevel analysis was applied to the data using generalized linear mixed models and a logit link function. The outcome variable was the presence/absence of Salmonella in the pen fecal samples. The first level was assigned to the pen fecal samples and the second level to the herds. The results showed significant associations between Salmonella occurrence and the factors (p < 0.05): maternity pens versus mating pens (OR = 0.39, 95%CI: 0.24–0.63), feed from external or mixed source versus home source (OR = 2.81, 95%CI: 1.19–6.61), more than 10 animals per pen versus 10 animals per pen (OR = 2.02, 95%CI: 1.19–3.43), North Region versus Alentejo Region (OR = 3.86, 95%CI: 1.08–13.75), rodents control (OR = 0.23, 95%CI: 0.090–0.59), more than 90% of boars homebred or no boars versus more than 90% of boars from an external source (OR = 0.54, 95%CI: 0.3–0.97), semen from another herd versus semen from insemination centers (OR = 4.47, 95%CI: 1.38–14.43) and herds with a size of 170 or more sows (OR = 1.82, 95%CI: 1.04–3.19). This study offers very relevant information for both the Portuguese veterinary authorities and the pig farmers currently developing control programmes for Salmonella. This is the first study providing evidence for semen and boars source as risk factors for Salmonella in breeding pigs.     

Comparison of the virulence of European and North American genotypes of porcine reproductive and respiratory syndrome virus in experimentally infected pigs

The objective of this study was to compare the virulence of Korean types 1 and 2 porcine reproductive and respiratory syndrome virus (PRRSV) isolated from weaned pigs with respiratory disease. Affected pigs were within the same herd and animals infected with type 2 virus had significantly higher mean rectal temperatures than those with type 1 virus between days 2 and 9 post-inoculation (P < 0.05). Similarly, mean serum viral titres, expressed as tissue culture infective doses 50% (TCID₅₀)/mL, as well as macroscopic and microscopic pulmonary lesion scores, were significantly higher at multiple time points in pigs infected with type 2 PRRSV compared to those infected with type 1 virus. Mean numbers of PRRSV-positive cells/unit area of lungs and lymph nodes were also significantly higher in type 2 PRRSV infected pigs. This study demonstrates that type 2 PRRSV is more virulent than type 1 PRRSV in this experimental setting as reflected by the pulmonary pathology induced, the extent of virus distribution, and oral shedding of the virus.     

Entamoeba infections in different populations of dogs in an endemic area of Lahore,Pakistan

Entamoeba histolytica, a protozoan parasite that affects humans and other primates all over the world. It is a common waterborne pathogen in endemic areas that have fecal oral transmission cycle. The aim of the present study was to examine the prevalence of E. histolytica and other Entamoeba species cysts in three different dog populations. Fecal samples from 600 dogs were collected and processed to detect Entamoeba cysts using the triple fecal test (light microscopy) and fecal antigens of E. histolytica were detected using a fecal antigen ELISA (TechLab E. histolytica II). Because it is impossible to differentiate E. histolytica from Entamoeba dispar and E. moshkovskii, using light microscopy we referred to all cysts morphologically consistent with E. histolytica as E. histolytica/dispar/moskovskii to reflect this uncertainty. Samples from 197 household dogs without clinical signs, 122 samples from household dogs exhibiting clinical signs of diarrhea, dysentery and vomiting and 281 stray dogs with no specific clinical signs were examined. Entamoeba histolytica-like cysts were observed in 94 (15.6%, 95% CI = ±3.88) by triple fecal test microscopy and E. histolytica antigens were demonstrated in 66 (11%, 95% CI = ±4.41) by fecal antigen ELISA in 600 fecal samples. Significant differences (P ≤ 0.05) in prevalence were found between the three populations. Twenty (10.1%, 95% CI = ±7.86) and 11 (5.6%, 95% CI = ±7.70) of 197 fecal samples from household dogs without clinical signs were positive by microscopy and by antigen ELISA, respectively. Twenty-nine (23.8%, 95% CI = ±6.58) and 23 (18.8%, 95% CI = ±7.81) of 122 the fecal samples from household dogs with clinical signs were positive by microscopy and by antigen ELISA, respectively. Forty-five (16.01%, 95% CI = ±5.62) and 32 (11.3%, 95% CI = ±6.38) of 281 fecal samples from stray dogs were positive by microscopy and by fecal antigen ELISA, respectively. Dogs from the youngest age group (6 months to 1 year) were more likely to be E. histolytica antigen positive than were dogs from the other two older age groups, with a significant difference (P ≤ 0.05) between all age groups. Statistically, no significant (P ≥ 0.05) difference of prevalence was seen in male and female dogs. The local dogs had the highest prevalence rate of E. histolytica antigens (36 of 246, 14.2%, 95% CI = ±6.32) followed by imported breeds (11 of 115, 9.5%, 95% CI = ±10.4) and crossbred (19 of 239, 8.3%, 95% CI = ±7.47), indicating a significant (P ≤ 0.05) trend of positivity between various breeds of dogs. These findings suggest that dogs may play an important role in the epidemiology of this pathogen.     

Cryptosporidium scrofarum n. sp. (Apicomplexa: Cryptosporidiidae) in domestic pigs (Sus scrofa)

We describe the morphological, biological, and molecular characteristics of Cryptosporidium pig genotype II and propose the species name Cryptosporidium scrofarum n. sp. to reflect its prevalence in adult pigs worldwide. Oocysts of C. scrofarum are morphologically indistinguishable from C. parvum, measuring 4.81–5.96 μm (mean = 5.16) × 4.23–5.29 μm (mean = 4.83) with a length to width ratio of 1.07 ± 0.06 (n = 400). Oocysts of C. scrofarum obtained from a naturally infected pig were infectious for 8-week-old pigs but not 4-week-old pigs. The prepatent period in 8-week-old Cryptosporidium-naive pigs was 4–6 days and the patent period was longer than 30 days. The infection intensity of C. scrofarum in pigs was generally low, in the range 250–4000 oocysts per gram of feces. Infected pigs showed no clinical signs of cryptosporidiosis and no pathology was detected. Cryptosporidium scrofarum was not infectious for adult SCID mice, adult BALB/c mice, Mongolian gerbils (Meriones unguiculatus), southern multimammate mice (Mastomys coucha), yellow-necked mice (Apodemus flavicollis), or guinea pigs (Cavia porcellus). Phylogenetic analyses based on small subunit rRNA, actin, and heat shock protein 70 gene sequences revealed that C. scrofarum is genetically distinct from all known Cryptosporidium species.     

Systemic and local immune response in pigs intradermally and intramuscularly injected with inactivated Mycoplasma hyopneumoniae vaccines

The systemic and respiratory local immune response induced by the intradermal administration of a commercial inactivated Mycoplasma hyopneumoniae whole-cell vaccine (Porcilis^® MHYO ID ONCE – MSD AH) in comparison with two commercial vaccines administered via the intramuscular route and a negative control (adjuvant only) was investigated. Forty conventional M. hyopneumoniae-free pigs were randomly assigned to four groups (ten animals each): Group A = intradermal administration of the test vaccine by using the needle-less IDAL^® vaccinator at a dose of 0.2 ml; Group B = intramuscular administration of a commercially available vaccine (vaccine B); Group C = intramuscular administration of the adjuvant only (2 ml of X-solve adjuvant); Group D = intramuscular administration of a commercially available vaccine (vaccine D). Pigs were vaccinated at 28 days of age. Blood and bronchoalveolar lavage (BAL) fluid samples were collected at vaccination (blood only), 4 and 8 weeks post-vaccination. Serum and BAL fluid were tested for the presence of antibodies by ELISA test. Peripheral blood monomorphonuclear cells (PBMC) were isolated to quantify the number of IFN-γ secreting cells by ELISpot. Moreover, cytokine gene expression from the BAL fluid was performed. Total antibodies against M. hyopneumoniae and specific IgG were detected in serum of intradermally and intramuscularly (vaccine B only) vaccinated pigs at 4 and 8 weeks post-vaccination. M. hyopneumoniae specific IgA were detected in BAL fluid from vaccinated animals (Groups A and B) but not from controls and animals vaccinated with the bacterin D (p < 0.05). Significantly higher gene expression of IL-10 was observed in the BAL fluid at week 8 post-vaccination in the intradermally vaccinated pigs (p < 0.05). The results support that the intradermal administration of an adjuvanted bacterin induces both systemic and mucosal immune responses. Moreover, the intramuscularly administered commercial vaccines each had a different ability to stimulate the immune response both systemically and locally.     

Evaluation of peripheral lymphocytes after weaning and vaccination for Mycoplasma hyopneumoniae

This study evaluated immune cell populations in pigs following weaning and vaccination for Mycoplasma hyopneumoniae. Piglets (n = 24) were weaned (day 0) at 16 (±1) days of age, and randomly assigned to the vaccination group (n = 16) or control group (n = 8). Complete blood cell counts, flow cytometry and serology were completed for blood samples collected on days 0 (within hours of weaning), 3, 7, 14, 30 and 60. The M. hyopneumoniae S:P ratios (sample optical density: positive control optical density) were negative in the vaccination group until days 30 and 60, when the S:P ratios were 1.3 and 1.0, respectively. Control animals remained serologically negative. The percentage of CD4⁺ T cells was less (P < 0.01) in control pigs than vaccinated pigs at day 3. In contrast, numbers of CD8⁺ and CD4⁺CD8⁺ T cells were greater (P < 0.01) in control pigs than in vaccinated pigs at days 3 and 7. After day 7, few differences in immune cell types were evident between the groups. Differences in lymphocyte populations could not be solely attributed to vaccination, due at least in part, to the confounding influence of weaning. It was difficult to distinguish the influence of vaccination from the impact of weaning on peripheral immune cell populations.     

Immune and inflammatory responses in pigs infected with Trichuris suis and Oesophagostomum dentatum

The aim of the present study was to investigate parasite induced immune responses in pigs co-infected with Trichuris suis and Oesophagostomum dentatum as compared to mono-species infected pigs. T. suis is known to elicit a strong immune response leading to rapid expulsion, and a strong antagonistic effect on O. dentatum populations has been observed in co-infected pigs. Forty-eight helminth naïve pigs were allocated into 4 groups in a 2-factorial design. Two groups were trickle inoculated with either 10 T. suis eggs/kg/day (Group T) or 20 O. dentatum L3/kg/day (Group O). Group OT was infected with same levels of both T. suis and O. dentatum (Group OT) and Group C remained uninfected. In each group, six pigs were necropsied after 35 days and the remaining pigs after 71 days. Parasite E/S-antigen specific serum antibodies were quantified by an in-direct ELISA. qPCR was used to measure the expression of immune function related genes in the mucosa of proximal colon and the draining lymph node. Highly significant interactions were identified for O. dentatum specific IgG1 (p < 0.0001) and IgG2 (p < 0.0006) antibodies with a remarkable 2-fold higher antibody response in group OT pigs as compared to group O. These findings indicated that T. suis enhanced the antibody response against O. dentatum in Group OT. The gene expression data confirmed a strong Type 2 response to T. suis (e.g. marked increase in IL-13, ARG1 and CCL11) and clearly weaker in amplitude and/or delayed onset response to O. dentatum in the single infected group. Interactions were found between the two nematodes with regard to several cytokines, e.g. the increase in IL-13 observed in Group T was absent in Group OT (p = 0.06, proximal colon mucosa, 35 and 71 p.i.). Some of these immune response-related interactions may support, or even partially explain, the observed interactions between the two worm populations in co-infected pigs.     

The critical threshold of Lawsonia intracellularis in pig faeces that causes reduced average daily weight gains in experimentally challenged pigs

Serology indicates that Lawsonia intracellularis infection is widespread in many countries, with most pigs seroconverting before 22 weeks of age. However, the majority of animals appear to be sub-clinically affected, demonstrated by the low reported prevalence of diarrhoea. Production losses caused by sub-clinical proliferative enteropathy (PE) are more difficult to diagnose, indicating the need for a quantitative L. intracellularis assay that correlates well with disease severity. In previous studies, increasing numbers of L. intracellularis in pig faeces, quantified with a real time polymerase chain reaction (qPCR), showed a strong negative correlation with average daily gain (ADG).In this study, the association between faecal L. intracellularis numbers and PE severity was examined in two L. intracellularis experimental challenge trials (n₁ = 32 and n₂ = 95). The number of L. intracellularis shed in individual faeces was determined by qPCR on days 0, 7, 14, 17 and 21 days post challenge, and average daily gain was recorded over the same period. The severity of histopathological lesions of PE was scored at 21 days post challenge. L. intracellularis numbers correlated well with histopathology severity and faecal consistency scores (r = 0.72 and 0.68, respectively), and negatively with ADG (r = ?0.44). Large reductions in ADG (131 g/day) occurred when the number of L. intracellularis shed by experimentally challenged pigs increased from 10⁷ to 10⁸ L. intracellularis, although smaller ADG reductions were also observed (15 g/day) when the number of L. intracellularis increased from 10⁶ to 10⁷ L. intracellularis.     

A cross-sectional study of risk factors associated with pulmonary lesions in pigs at slaughter

A cross-sectional study was conducted to identify herd-level factors that may influence the prevalence and severity of macroscopically visible pulmonary lesions in pigs at slaughter. Data were collected following abattoir inspection of 50 randomly-selected batches of 6335 pigs and by interviewing the producers. Macroscopic lung lesions were identified and scored semi-quantitatively in ?80 pigs/herd and the prevalence of pleuritis and pneumonia was 20.76% and 23.85%, respectively. Following multivariable analysis, the seroprevalence of Actinobacillus pleuropneumoniae (P < 0.001) and Mycoplasma hyopneumoniae (P = 0.018) and the number of pigs/nursery pen (P = 0.023) were positively associated, whereas average weaning age was negatively associated (P = 0.001) with the pleuritis score. Risk factors associated with a higher prevalence of pneumonia were the presence of pleuritis (P = 0.001) and the frequent purchasing of pigs (P = 0.020). The findings of this study indicate that the prevalence of pleuritis and pneumonia remains high in Belgium and management factors are central to disease control.     

The effect of sea transport from Ireland to the Lebanon on inflammatory,adrenocortical, metabolic and behavioural responses of bulls

The objective was to investigate the effect of sea transport on the physiological, behavioural and performance responses of bulls. One-hundred and eleven bulls (mean body weight (standard error of the mean) 429 (5.7 kg)) were randomly assigned to one of three treatments; control (C; n = 54) bulls were housed in 6 pens at Teagasc, Grange Research Centre at a stocking density of (1), 1.7 m²/head (C1.7; 3 pens) and (2), 3.4 m²/head (C3.4; 3 pens) and (3), transported (T) bulls (n = 57) were penned at a space allowance of 1.7 m²/head (6 pens) and allocated to one of five decks on the shipping vessel. C and T bulls were subjected to the same live weight (d −2), blood sampling and rectal temperature (d −1) measurements pre-transport and on d 3, d 6, d 9 and d 11 of the study. T bulls had greater (P < 0.05) live weight gain (+4.4%) compared with C1.7 bulls (−2.0%) and C3.4 (+0.13%)). Time spent lying was greater (P < 0.05) among C1.7 and C3.4 bulls (9.9% and 53.3%, respectively) compared with T bulls (45.8%). Rectal body temperature was not different (P > 0.05) among treatment groups throughout the study. At d 11, neutrophil % was greater (P < 0.05) in transported bulls on decks 1, 2, 4 and 5 compared with C1.7 and C3.4 treatments. Plasma cortisol concentrations were not different (P > 0.05) between control and transported bulls. Plasma creatine kinase (CK) activity was lower (P < 0.05) among C3.4 and T bulls on decks 2, 3, 4 and 5 compared with d 3 values. In conclusion, the welfare of bulls transported by sea on the sea journey was not adversely affected. Housing control bulls at a reduced space allowance (1.7 m²) had a negative effect on live weight gain.     

Detection of trichinellosis in a historically Trichinella-free area of Argentina

The aim of the present work was to determine the presence of human and porcine trichinellosis in an area of Argentina historically regarded as Trichinella-free. Human blood donors (n = 216) and swine destined for consumption (n = 57) were evaluated by serological techniques (ELISA, immunofluorescence, and/or Western Blot). Muscle tissues from 26 of the pigs were evaluated for the presence of Trichinella larvae by the artificial digestion method. A questionnaire was used to collect and evaluate data on eating habits of the human population under study and on swine-raising conditions. The survey showed that 98.1% of the individuals (n = 212) were regular consumers of pork in the form of stuffed products such as sausages produced by local butchers. The seroprevalence (positive sera by at least two of the three methods) was 8.3% (n = 18) for human trichinellosis and 24.5% (n = 14) for porcine trichinellosis. Trichinella spiralis larvae were found in 2 of the 26 pigs (7.7%) with parasite loads of 0.33 and 2.4 muscle larvae per gram. Twelve swine found positive by serological and/or parasitological tests were raised under poor sanitary conditions (presence of rubbish in the surroundings, with cannibalism and scavenging behaviors, presence of rodents, etc.). Our study confirms the existence of porcine trichinellosis in an area regarded as Trichinella-free, provides supporting serological evidence of human infection in this area, and indicates that failure to report cases of trichinellosis based on inadequate surveillance can result in incorrect prevalence classification of an area.     

A field trial of infrared thermography as a non-invasive diagnostic tool for early detection of digital dermatitis in dairy cows

Infrared thermography (IRT) was used to detect digital dermatitis (DD) prior to routine claw trimming. A total of 1192 IRT observations were collected from 149 cows on eight farms. All cows were housed in tie-stalls. The maximal surface temperatures of the coronary band (CB) region and skin (S) of the fore and rear feet (mean value of the maximal surface temperatures of both digits for each foot separately, CB_max and S_max) were assessed. Grouping was performed at the foot level (presence of DD, n = 99; absence, n = 304), or at the cow level (all four feet healthy, n = 24) or where there was at least one DD lesion on the rear feet, n = 37). For individual cows (n = 61), IRT temperature difference was determined by subtracting the mean sum of CB_max and S_max of the rear feet from that of the fore feet.Feet with DD had higher CB_max and S_max (P < 0.001) than healthy feet. S_max was significantly higher in feet with infectious DD lesions (M-stage: M2 + M4; n = 15) than in those with non-infectious M-lesions (M1 + M3; n = 84) (P = 0.03), but this was not the case for CB_max (P = 0.12). At the cow level, an optimal cut-off value for detecting DD of 0.99 °C (IRT temperature difference between rear and front feet) yielded a sensitivity of 89.1% and a specificity of 66.6%. The results indicate that IRT may be a useful non-invasive diagnostic tool to screen for the presence of DD in dairy cows by measuring CB_max and S_max.     

Giardia and Cryptosporidium infections in neonatal reindeer calves: Relation to the acute phase response

This longitudinal observational study was conducted to investigate the spontaneous effect of Giardia and Cryptosporidium infections on acute phase response (APR) in reindeer calves (Rangifer tarandus tarandus) in Finnish Lapland.Serum (n = 609) and faecal samples (n = 366) were collected from 54 reindeer calves aged zero to 33 days. The samples were analysed for Giardia, Cryptosporidium, acute phase proteins (APP) and γ-globulins.Linear regression models were used to investigate associations of early Giardia infection (before 12 days of life) with the response of APPs and acquiring of passive immunity.Giardia was detected in 100% and Cryptosporidium in 23% of calves. There was a negative association between early Giardia infection and γ-globulin concentrations (p = 0.032) and a positive association with serum amyloid A (SAA) concentrations (p = 0.042). The results suggest a protective effect of colostrum against Giardia infection and that early infection may induce activation of APR.     

Effects of isoflurane upon minimum alveolar concentration and cerebral cortex depression in pigs and goats: An interspecies comparison

This study compared the effects of isoflurane in pigs (n = 10 Yorkshire–Landrace cross) and dairy goats (n = 10) by evaluation of electroencephalographic (EEG) burst suppression thresholds (BST) in the cerebral cortex and minimum alveolar concentration (MAC) values in the spinal cord. The study also investigated whether individual MAC values can predict the effects of isoflurane on the cerebral cortex. MAC values and BST/MAC ratios were significantly different between species. Inhibition of movement by isoflurane may be less effective in pigs than in goats. No significant correlation was found between individual MAC and BST values, indicating that in single animals the individual MAC poorly reflects the cerebrocortical depressant effect of isoflurane in pigs and goats.     

Expression of trefoil factor genes in the duodenum and colon of dogs with inflammatory bowel disease and healthy dogs

Trefoil factors (TFF) are small peptides produced by goblet cells, which are crucial for epithelial restitution. In humans with inflammatory bowel disease (IBD), TFF expression is up-regulated as part of an unspecific repair mechanism. The goal of this study was to assess TFF gene expression in the gastrointestinal tract from dogs with IBD compared to healthy controls. Preliminary assessment by PCR revealed TFF1 and 3 expression in the small and large intestine, whereas TFF2 was amplified only in the stomach. Subsequent RT-qPCR (with relative quantification against 3 reference genes) on endoscopic duodenal (IBD n = 22, healthy controls n = 18) and colonic (IBD n = 12, controls n = 11) biopsies revealed that TFF1 expression was significantly up-regulated in the duodenum from IBD dogs (Mann–Whitney p = 0.001), whereas TFF3 expression was significantly lower in IBD colon compared to controls (t-test p = 0.018).This study demonstrates evidence for dysregulation of TFF gene expression in canine IBD. Up-regulation of TFF1 could signify ectopic expression as a compensatory repair-mechanism, whereas down-regulation of TFF3 could contribute to defective epithelial barrier function, respectively. Whether this is a cause or consequence of IBD could not be established.     

Frequency of virulence factors in Escherichia coli isolated from suckling pigs with diarrhoea in China

Escherichia coli-associated diarrhoea is an important disease adversely affecting the pig industry. This study was conducted to investigate the frequency of virulence factors expressed by E. coli strains isolated from suckling pigs with diarrhoea in China. A total of 381 E. coli strains, obtained from 290 faecal samples from pigs on 38 farms, were tested for fimbriae (K88, K99, 987P, F41, F18, F17), non-fimbrial adhesins (AIDA-I, paa, CS31A, eae, saa), enterotoxin (LT-I, LT-II, STa, STb, EAST1), Shiga toxin (Stx1, Stx2, Stx2e), pathogenicity islands (HPI, LEE), α-haemolysin (hlyA), afa8 gene cluster (afaD, afaE) and sepA genes by PCR. Out of the 381 isolates, 206 carried at least one virulence gene. Of the 206 virulence positive isolates, the virulence factor genes detected were EAST1 (n = 120), irp2 (n = 59), paa (n = 50), STb (n = 41), AIDA-I (n = 34), LT-I (n = 23), ler (n = 11), hlyA (n = 9), K88 (n = 8), eae (n = 8), STa (n = 7), sepA (n = 6), F18 (n = 5), afaD (n = 3), afaE (n = 3), K99 (n = 2) and Stx2e (n = 1), with most isolates carrying multiple virulence genes. These results demonstrate that relatively few isolates from the study population express K88, K99, LT-I or STa, but that EAST1 (58%), irp2 (29%), AIDA-I (16.5%), paa (24%) and STb (20%) are frequent virulence factors expressed by E. coli strains isolated from suckling pigs with diarrhoea in China.     

Electroencephalographic assessment of oral meloxicam,topical anaesthetic cream and cautery iron for mitigating acute pain in pigs (Sus scrofa) undergoing tail docking

Objective

To evaluate the efficacy of oral meloxicam, topical anaesthetic cream and cautery iron in mitigating acute nociceptive responses of pigs to tail docking.

Pharmacokinetics and ex vivo pharmacodynamics of cefquinome in porcine serum and tissue cage fluids

A tissue cage (TC) model was used to evaluate the pharmacokinetics and ex vivo pharmacodynamics of cefquinome after intravenous (IV) and intramuscular (IM) administration to piglets at 2 mg/kg bodyweight. The mean values of area under the concentration–time curve (AUC) were 21.28 (IV) and 21.37 (IM) μg h/mL for serum, and 17.40 (IV) and 16.57 (IM) μg h/mL for TC fluid (TCF), respectively. Values of maximum concentration (C_max) were 6.15 μg/mL (serum) and 1.15 μg/mL (TCF) after IM administration. The elimination half-lives (t_1/2β) in TCF (10.63 h IV and 11.81 h IM) were significantly higher than those in serum (2.33 h IV and 2.30 h IM) (P < 0.05). The values of AUC_TCF/AUC_serum (%) after IV and IM administration were 82.4% and 80.7%, respectively.The ex vivo time-kill curves were established for serum and TCF samples using Escherichia coli ATCC 25922. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration values of cefquinome against E. coli were 0.030 and 0.060 μg/mL in Mueller–Hinton broth, and 0.032 and 0.064 μg/mL in both serum and TCF, respectively. The ex vivo growth inhibition data of TCF after IM administration were fitted to the sigmoid E_max model; AUC_24h/MIC was 35.01 h for bactericidal activity and 44.28 h for virtual eradication, respectively. The findings from this study suggest that cefquinome may be therapeutically effective in diseases of pigs caused by E. coli when used at a dose rate of 1.33 mg/kg administered every 24 h for organisms with MIC₉₀ ⩽ 0.50 μg/mL.