Disease Control, Prevention and On-Farm Biosecurity: The Role of Veterinary Epidemiology

Domesticated and non-domesticated animals, including wildlife, deliver significant financial and nonfinancial benefits to the human community;however, disease can have a dramatic impact on the morbidity, mortality, and productivity of these animal populations and hence can directly and indirectly affect the human communities associated with them. This manuscript provides an overview of the important features to consider for the prevention and control of disease, with a focus on livestock diseases,and highlights the key role veterinary epidemiology plays in this endeavor. Measures of disease frequency and the type of epidemiological studies required to identify risk factors for diseases are summarized,with a focus on the use of these in the implementation of measures to control disease. The importance of biosecurity in maintaining disease-free flocks/herds is discussed and the steps taken to implement good biosecurity measures are outlined. It is concluded that a sound knowledge of veterinary epidemiology is required when developing control programs for disease and implementing biosecurity programs at a farm, regional, and national level.

Immunogenicity of formaldehyde and binary ethylenimine inactivated infectious bursal disease virus in broiler chicks

Infectious bursal disease virus (IBDV) was inactivated by two different chemicals—formaldehyde and binary ethylenimine (BEI). Formaldehyde was used at 0.1% and 0.2%, while BEI was used at concentrations of 0.001 and 0.002 mol/L. These four vaccines were tested for their efficiency in generating humoral immune response in different groups of broiler chicks. Both BEI-inactivated vaccines gave relatively higher antibody titers and were almost twice as efficient as formaldehyde-inactivated ones.

Titanium dioxide induced inflammation in the small intestine

AIM:To investigate the effects of titanium dioxide (TiO2) nanoparticles (NPTiO 2 ) and microparticles (MPTiO 2 ) on the inflammatory response in the small intestine of mice. METHODS: Bl 57/6 male mice received distilled water suspensions containing TiO 2 (100 mg/kg body weight) as NPTiO 2 (66 nm), or MPTiO 2 (260 nm) by gavage for 10 d, once a day; the control group received only distilled water. At the end of the treatment the duodenum, jejunum and ileum were extracted for assessment of cytokines, inflammatory cells and titanium content. The cytokines interleukin (IL)-1b, IL-4, IL-6, IL-8, IL-10, IL-12, IL-13, IL-17, IL-23, tumor necrosis factor-α (TNF-α), intracellular interferon-γ (IFN-γ) and transforming growth factor-β (TGF-β) were evaluated by enzyme-linked immunosorbent assay in segments of jejunum and ileum (mucosa and underlying muscular tissue). CD4 + and CD8 + T cells, natural killer cells, and dendritic cells were evaluated in duodenum, jejunum and ileum samples fixed in 10% formalin by immuno-histochemistry. The titanium content was determined by inductively coupled plasma atomic emission spectrometry. RESULTS: We found increased levels of T CD4 + cells (cells/mm 2 ) in duodenum:NP 1240 ± 139.4, MP 1070 ± 154.7 vs 458 ± 50.39 (P < 0.01); jejunum:NP 908.4 ± 130.3, MP 813.8 ± 103.8 vs 526.6 ± 61.43 (P < 0.05); and ileum:NP 818.60 ± 123.0, MP 640.1 ± 32.75 vs 466.9 ± 22.4 (P < 0.05). In comparison to the control group, the groups receiving TiO 2 showed a statistically significant increase in the levels of the inflammatory cytokines IL-12, IL-4, IL-23, TNF-α, IFN-γ and TGF-β. The cytokine production was more pronounced in the ileum (mean ± SE):IL-12: NP 33.98 ± 11.76, MP 74.11 ± 25.65 vs 19.06 ± 3.92 (P < 0.05); IL-4: NP 17.36 ± 9.96, MP 22.94 ± 7.47 vs 2.19 ± 0.65 (P < 0.05); IL-23: NP 157.20 ± 75.80, MP 134.50 ± 38.31 vs 22.34 ± 5.81 (P < 0.05); TNFα: NP 3.71 ± 1.33, MP 5.44 ± 1.67 vs 0.99± 019 (P < 0.05); IFNγ: NP 15.85 ± 9.99, MP 34.08 ± 11.44 vs 2.81 ± 0.69 (P < 0.05); and TGF-β: NP 780.70 ± 318.50, MP 1409.00 ± 502.20 vs 205.50 ± 63.93 (P < 0.05). CONCLUSION:Our findings indicate that TiO2 particles induce a Th1-mediated inflammatory response in the small bowel in mice.

Calcium potentiates the effect of estradiol on PGF2α production in the bovine endometrium

Background： Estradiol （E2） is required for luteolysis in cows and its injection stimulates prostaglandin F2α （PGF2α） release. The main goal of our study was to investigate the ability of endometrial explants and cells treated with E2 and the calcium ionophore （CI） A23187 to synthesize PGF2α. Results： Treatment with E2 in vivo resulted in a 48.4% increase of PGF2α production by endometrial explants treated in vitro with A23187. Production of PGF20 was better stimulated with A23187 at concentrations of 10^-6 and 10^-5 mol/L compared with other concentrations used. The concentration of PGF2α for untreated bovine endometrial cell cultures was 33.1 pg/mL, while for cultures treated with E2, A23187, or a combination of E2 and A23187, the PGF2α concentration was 32.5, 92.4 and 145.6 pg/mL, respectively. Conclusions： Treatment with A23187 tended to stimulate PGF20 production. In the presence of E2, A23187 significantly stimulated PGF20 synthesis. It appears that A23187 potentiates the effects of E2 with respect to synthesis of endometrial PGF2α in cattle.

In vitro scolicidal effect of Satureja khuzistanica(Jamzad)essential oil

Objective:To investigate the scolicidal effect of the Satureja khuzistanica(S.khusistanica) essential oil from aerial parts of this herbal plant.Methods:The essential oil was obtained by hydrodistillation method.Gas chromatography(GC) and gas chromatography mass spectrometry(GC-MS) were employed to determine the chemical composition of the essential oil.Protoscolices were collected aseptically from sheep livers containing hydatid cyst.Protoscolices were exposed to various concentrations of the oil(3,5 and 10 mg/mL) for 10,20,30,and 60 min.Viability of protoscolices was confirmed by 0.1%eosin staining.Results:A total of 19 compounds representing 97.6%of the total oil,were identified.Carvacrol(94.9%) was found to be the major essential oil constituent.Scolicidal activity of S.khuzistanica essential oil at concentration of 3 mg/mL was 28.58,32.71,37.20 and 42.02%,respectively.This essential oil at concentration of 5 mg/ mL killed 51.33,66.68,81.12,and 100%.of protoscolices after 10,20,30 and 60 min,respectively. One hundred scolicidal effect was observed with S.khuzistanica essenlial oil at the concentration of 10 mg/mL after 10 min(comparing with 7.19%for control group).Conclusions:The essenlial oil of S.khuzistanica is rich in carvacrol and may be used as a natural scolicidal agent.

Comparative study of Anaplasma parasites in tick carrying buffaloes and cattle

A comparative study on the prevalence of Anaplasma parasite was conducted on ticks carrying buffaloes and cattle. Five hundred blood samples of both animals (250 of each) were collected during February, March and April. Thin blood smears on glass slides were made, fixed in 100% methyl alcohol and examined. Microscopic examination revealed that 205 (41%) animals had Anaplasma parasites, out of which 89, 44 and 72 animals had Anaplasma marginale, Anaplasma centrale and mixed infection respectively. Infected buffaloes and cattle were 75 and 130 respectively. The infection in female was 53 and 92 in buffaloes and cattle respectively. Twenty-two and 92 blood samples of male were found positive in buffaloes and cattle respectively. Com- parative study revealed that the cattle were 26.82% more susceptible than buffaloes. The parasite prevailing percentage in female of both animals was slightly higher than that of the male. This investigation was aimed at studying the comparative prevalence of Anaplasma parasite in tick carrying buffaloes and cattle.

Intra-articular transplantation of porcine adipose-derived stem cells for the treatment of canine osteoarthritis: A pilot study

AIM: To test whether intra-articular injection of porcine adipose-derived stem cells(ADSCs) can treat canine osteoarthritis(OA).METHODS: To enroll in this study dogs must have stifle joint OA that had lasted ≥ 3 mo and been treated with OA medication without significant improvement. Three dogs fulfilled these criteria and were thus subjects for ADSCs treatment. ADSCs were isolated from abdominal adipose tissue of a 2-mo-old female Yorkshire pig. Their stem cell marker expression was examined by immunofluorescence staining. For treatment, 5 million ADSCs were injected into the diseased joint of each dog. In the next 48 h, the patient was observed for signs of inflammatory and allergic reactions. Thepatient was then discharged to the owner and, at 2, 6, and 12 wk, followed up with orthopedic assessment, owner questionnaire, X-ray imaging, and force-plate gait analysis.RESULTS: Porcine ADSCs expressed mesenchymal stem cell markers CD90 and CD105. Injection of porcine ADSCs into canine stifle joints did not cause any inflammatory or allergic reactions. Orthopedic evaluation found improvements in two dogs, particularly at the longest time point. Owners' evaluation found increased capacity and decreased pain in all three dogs' activities such as walking and running. Radiographic evaluation did not find statistically significant differences before and after treatment. Force-plate analysis found significant improvements in all three dogs after treatment.CONCLUSION: Xenotransplantation of ADSCs for the treatment of OA is feasible. Further studies are needed to validate this novel treatment modality, which can then be implemented for the routine treatment of OA in veterinary medicine.

Congenital sternal foramen in a stillborn Holstein calf

Congenital sternal foramen is an anomaly whose occurrence is rare in human but is especially unusual in animals.This defect was formed when fusion of multiple ossification centers was incomplete.It may be associated with other lesions in body organs especially cardiac anomalies.In the present study,we report a very rare case of congenital sternal foramen in a Holstein calf.The oval defect was like a gunshot wound and located at the lower third of the sternum.Apparently,the rest of skeleton system seems normal.The awareness of the anomaly is important for better diagnosis and treatment of diseases.

High expression level of soluble SARS spike protein mediated by adenovirus in HEK293 cells

AIM： To develop a highly efficacious method for preparation of soluble SAPS S-protein using adenovirus vector to meet the requirement for S-protein investigation. METHODS： The human adenovirus vector was used to express the soluble S-protein （corresponding to 1-1190 amino acids） fused with Myc/His tag using codon-optimized gene construct in HEK239 cells. The recombinant adenovirus bearing S-protein gene was generated by ligation method. The expressed S-protein with Myc/His tag was purified from culture medium with Ni-NTA agarose beads followed by dialysis. The S-protein was detected by Western blot and its biologic activity was analyzed by binding to Vero cells. RESULTS： Under the conditions of infection dose （MOI of 50） and expression time （48 h）, the high-level expression of S-protein was obtained. The expression level was determined to be approximately 75 μg/106 cells after purification. Purified soluble S-protein was readily detected by Western blot with anti-Myc antibody and showed the ability to bind to surface of Vero cells, demonstrating that the soluble S-protein could remain the biologic activity in the native molecule. CONCLUSION： The high-level expression of S-protein in HEK293 cells mediated by adenovirus can be achieved under the optimized expression conditions. The proteins possess the biologic activity, which lays a foundation for further investigation of S-protein biological function.

Evaluation of Pre-Cecal, Ileal Digestibility and Glycemic Response in Fistulated Horses Fed with Different Starch Sources

The objective of this study was to evaluate the coefficients of pre-cecal, ileal digestibility, and glycemic response in cannulated horses fed with different starch sources. Four male horses were used in a 4 × 4 Balanced Latin Square cannulated in the cecum, with 36 months of age and average weight of 350 kg. The horses were fed with hay and the following sources of starch in concentrates: 1) corn (C);2) oats (O);3) sorghum (S);and 4) corn/oats (CO). The experiment consisted of four periods of eighteen days each, being the first twelve days of adaptation and six days to collect samples. There was no difference in cecal and ileal digestibility of starch, CP, ADF, NDF and OM among diets evaluated. However, horses fed with oats diet had higher values of pre-cecal apparent digestibility of DM in relation at the horses fed to sorghum and corn/oats diets. The values of CF digestibility were higher for equines fed with oats and sorghum diet compared to corn/oats diet. The horses fed with corn/oats diet had lower plasma glucose concentrations 30 minutes before the supply and higher insulin concentrations 210 minutes after ingestion of the foods. The digestibility of nutrients in equine diets, in pre-cecal and pre-ileal evaluation, presents significant differences, depending on the starch source provided, oat, corn or sorghum. The plasma glucose concentrations are directly correlated with the digestibility of starch.

Effort and Recovery in Nellore Oxen during Vaquejada Assessed with Ocular and Tail Infrared Thermography Superficial Temperature

Infrared thermography (IRT) has emerged for evaluation of animal welfare. To test the hypothesis that cattle subjected to vaquejada increased temperature in the eye (CLO) and tail due to physical effort, a research was developed that aimed to measure maximum surface temperature in the CLO and base of tail using IRT. Eighty Nellore cattle were used, which were subjected to physical effort in three periods (morning, afternoon and night). IRT was performed at CLO and base of tail, in rest pen/corral (control) and during the vaquejada (pre- and post-run). Tails’ analysis was divided in 3 points (E1, E2 and E3). ANOVA and Tukey’s test (p < 0.001) were used for analysis. Temperatures were higher in morning and afternoon and different from those at night on control (p < 0.001). During vaquejada with one run, CLO was higher in pre-run, followed by a slight reduction in post-run (p < 0.001). Analyzing temperatures variations at tail, higher temperatures were observed in the morning, followed by the evening and night (p < 0.001), but without differences within the pre- and post-run periods. Temperatures at tail’s points were higher in morning period in cattle with two runs (p < 0.001). Finally, it was concluded that there were no increases in CLO or at tail’s points after vaquejada races. The IRT method was efficient in determining surface temperatures in CLO and tail points in cattle under the same conditions and may be a good noninvasive method for clinical and welfare assessments.

Raising of Horn Fly Haematobia irritans(L.)(Diptera:Muscidae)in Laboratory by Means of Egg and Larva Inoculation

Several studies have required Haematobia irritans (L.) raising in laboratory. The present study assessed two methods of inoculating immature forms of H. irritans to obtain adults. In 2007, 15 Nellore steers (Bos indicus) (L.) were used for the collection of feces free of anthelmintic treatment and flies to produce for eggs and larva. For method I, 30 eggs were incubated in square filter paper (5 × 5 cm) and deposited on bovine feces (500 g) where they were kept until hatching and spontaneous penetration of larvae (L1) into the fecal mass. After 24 h, eggs were analyzed under a stereoscope microscope (40×) for the number of larvae that instinctively penetrated the feces. In method II, larvae were obtained only by natural egg hatching. At birth, 30 larvae were collected and individually inoculated, directly onto the fecal plate by employing a moistened brush. The tests were carried out at controlled temperature (28°C ± 2°C) and saturated humidity (80%) until the emergence of flies with both methods. The number of emerged flies was considered in the result. Using method I, 276 (76.7%) flies emerged from 360 inoculated eggs, while using method II, 283 (78.6%) flies emerged from 360 inoculated larvae. There was no significant difference (P = 0.7821) between methods for the number of flies;however, the proportion between males and females by means of larva inoculation was different from 1:1 (P = 0.0146). Results indicated that both methods led to a satisfactory production of flies and egg inoculation provided an easier establishment.

Eosinophilic gastroenteritis in basset hound dog

An 1-year-old male Basset Hound dog was evaluated for chronic intermittent vomiting, hematemesis, and melena which had been ongoing for several months. The histopathologic examination revealed that all layers of the small intestine were thicker than normal. The lamina propria of the mucosa, including the villi, exhibited a prominent cellular infiltrate which consisted of numerous eosinophils and an increased numbers of plasma cells in addition to the normal lymphocytic component. The muscularis mucosa was invaded, and in some places disrupted, by eosinophils, which also infiltrated into the submucosa and muscularis propria. This report describes the pathological findings of a case of eosinophilic gastroenteritis (EG) in a dog.

The Impact of different warming devices on bacteria contamination in surgical field

Anesthesia may cause the development of hypothermia.By altering the physiologic mechanisms of thermoregulation,such as redistribution of blood flow,reducing metabolic rate,and vasodilatation,heat generation is decreased and heat loss is increased.Anesthesia related hypothermia is potentially associated with complications including coagulopathy,myocardial ischemia,surgical wound infection,etc.Demonstrated by numerous studies,convection warmers are though to be the most effective active warming device and are widely accepted in veterinary medicine for maintaining normother-