The effect of water intake prior to blood sampling on packed cell volume in sheep

The effect of water intake prior to blood sampling on subsequent packed cell volume (PCV) was investigated in ewe lambs (8 months of age) of the Dohne Merino, Merino and Letelle flocks at Grootfontein Agricultural Development Institute. On the afternoon of the day before the experiment was conducted, a blood sample for a baseline PCV value (R) was taken from each animal. The following day, 15 ewes of each breed (n = 45) were dosed with 1 litre of water and another 15 of each (n = 45) were used as a control. Blood samples for PCV were taken concurrently for both the control and water treatment groups before the dose (0), and at 15, 30 and 60 minutes after dosing. PCV were subsequently determined with the microcapillary centrifuge technique. Baseline PCV of Letelle ewes was higher (32.4 +/- 0.6) than that of the Dohne Merino (29.7 +/- 0.6) and Merino (28.7 +/- 0.6) ewes. Furthermore, recovery rate at 30 minutes after treatment also differed among breeds. Although there were significant differences between the control and water treatment groups at R and 0 minutes, which were probably due to inherent animal differences, there were no significant differences between PCV of the 2 groups during the remainder of the experimental period. Overall it can be concluded that water intake before blood sampling for the determination of PCV has no significant effect on haematocrit. Differences among breeds were more pronounced than those between treatment groups.     

Molar absorbance of cyanmethemoglobin from blood of different animals.

The molar absorbance of cyanmethemoglobin at 540 nm was measured in 35 species of mammals, birds, and reptiles. Values obtained were compared with those measured on human cyanmethemoglobin by the same procedure. There was no significant difference (P greater than or equal to 0.1) between the human and animal blood values observed in 29 samples. In six cases (4 mammals, 1 reptile, and 1 bird), the significant difference (P greater than or equal to 0.05) did not exceed 5% of the human value. The practice of applying the accepted absorbance of 1.10 x 10(4) M-1 cm-1 per mole of iron in human cyanmethemeglobin for the analysis of animal blood will not cause more than 5% uncertainty. Such results are satisfactory for use in clinical veterinary medicine except for those research projects concerned with animal hemoglobin function and structure.     

Comparison of whole blood and plasma potassium concentrations in dogs using the Reflovet system

Background: The Reflovet system is designed for chemical analysis of whole blood. However, plasma or serum is recommended for potassium analysis because of possible interference from RBC potassium. Because RBC potassium concentration is low in most canine erythrocytes, however, there should be little or no interference.
Objective: The objective of this study was to compare potassium results obtained in whole blood and in plasma from dogs using the Reflovet system.
Methods: Blood samples were collected from 104 dogs into lithium-heparin tubes. The potassium concentration was measured in whole blood, and subsequently the PCV was measured. Samples were centrifuged and the potassium concentration was measured in plasma. Comparisons were made using Deming's regression and Bland-Altman difference plots.
Results: There was very good correlation between results of potassium measurements in whole blood and plasma ( r = 0.93). Potassium values were moderately lower in whole blood: Potassium_blood= 0.912 × Potassium _plasma+ 0.119. Hemolysis had a negligible effect on the results, but the difference increased with the PCV value. In more than 90% of samples, the difference between the 2 measurements was ≤ 0.3 mmol/L.
Conclusion: There is only a negligible difference in most cases between potassium values in canine plasma and whole blood using the Reflovet system.     

Effect of specimen collection and storage on blood glucose and lactate concentrations in healthy,hyperthyroid and diabetic cats

Abstract: The objective of this study was to compare and investigate differences in glucose and lactate concentrations in sodium fluoride/potassium oxalate (NaF/Ox) plasma and serum in healthy cats and cats with metabolic disease. Glucose and lactate concentrations were determined in routinely processed serum and NaF/Ox plasma obtained from healthy (n = 30), hyperthyroid (n = 27) and diabetic (n = 30) cats, and in samples from 6 healthy cats stored at 25°C or 4°C for 0,1, 2, 4, or 8 hours. The packed cell volume (PCV) of blood collected in NaF/Ox was compared with that of blood collected in EDTA. Mean glucose concentration was significantly (P < .05) lower in NaF/Ox plasma than in serum in all groups of cats, by 0.7–2.5 mmol/L (11–45 mg/dL); the difference was greater in cats with hyperglycemia. Mean lactate concentration was significantly higher in serum than in NaF/Ox plasma in all groups of cats, by 0.4–1.2 mmol/L (3.6–10.8 mg/dL); the difference was greater in hyperthyroid and diabetic cats. In vitro, only serum stored on the clot for ≥ 1hour at 25°C had significantly lower glucose and higher lactate concentrations. The PCV of NaF/Ox-anticoagulated blood was lower than that of EDTA-anticoagulated blood, by 7.0%± 1.4% (P<.01). In conclusion, collection of feline blood in NaF/Ox was necessary to prevent in vitro increases in lactate concentration; however, NaF/Ox artifactually decreased plasma glucose concentration because of RBC shrinkage. The PCV should not be determined on blood collected in NaF/Ox.     

Effects of blood collection for transfusion on arterial blood pressure, heart rate, and PCV in cats

BACKGROUND: Collection of 50 mL of blood (standard unit) in cats is a common procedure. There are several studies on the health status of donors, but to our knowledge there are no reports on the effects of blood collection on the feline donor. HYPOTHESIS: Collection of a standard unit of blood from cats does not significantly change arterial blood pressure (BP), mean arterial pressure (MAP), systolic arterial pressure (SAP), diastolic arterial pressure (DAP), PCV, and heart rate (HR) in healthy blood donor cats. ANIMALS: Twenty-six healthy blood donor cats (6 spayed females and 20 castrated males). METHODS: An oscillometric method was used to measure MAP, SAP, DAP, and to quantify HR before and after blood collection; PCV was obtained before and immediately after blood collection. RESULTS: Despite a significant decrease (P < .05) in all variables (ie, BP, PCV, HR) after blood collection, no adverse events were observed. CONCLUSIONS AND CLINICAL IMPORTANCE: The collection of a unit of blood for transfusion from healthy donor cats weighing more than 5 kg appears to be safe, but this procedure leads to a decrease in arterial BP, PCV, and HR.     

不同检测仪器对SD大鼠血液生理指标测定的影响

目的：比较实验动物专用血细胞分析仪与医用血细胞分析仪对SD大鼠血液生理指标测定值的差异,分析检测仪器对大鼠血液生理指标测定的影响。方法：36只SD大鼠,体重约200 g,雌雄各半,屏障环境饲养,试验前禁食12 h,麻醉后采血,分别用实验动物专用血细胞分析仪与医用血细胞分析仪测定20项血液生理指标。结果：两种仪器分别检测的SD大鼠的平均血红蛋白浓度、平均血红蛋白含量、白细胞数量、淋巴细胞数量、单核细胞数量、嗜碱性粒细胞数量、嗜中性白细胞百分比、单核细胞百分比、嗜酸性粒细胞百分比、嗜碱性粒细胞百分比、淋巴细胞百分比、血小板数量、血小板分布宽度差异极显著（P＜0.01）;血红蛋白浓度、嗜中性白细胞数量、红细胞分布宽度差异显著（P＜0.05）;红细胞数量、红细胞压积、平均红细胞体积、嗜酸性粒细胞数量差异不显著（P＞0.05）。结论：不同检测仪器对SD大鼠血液学指标的检测有影响。     

Tarsal degenerative joint disease in cattle: blood and synovial fluid changes.

Tarsal degenerative joint disease (DJD) in 27 cattle was classified as primary or secondary based on age, joint conformation defects, faulty hindlimb alignment, or history of trauma to the affected joint(s). Results of blood and synovial fluid analysis for cattle affected with primary or secondary tarsal DJD were grouped in compilation of data. Cattle with tarsal DJD had significantly (P smaller than 0.01) reduced hemoglobin (Hb) content in comparison to that in control cattle. There was highly significant (P smaller than 0.001) reduction in packed cell volume (PCV). A significant difference was not determined for mean corpuscular hemoglobin concentration (MCHC) values of the 2 groups of cattle. Total white blood cell (WBC) counts closely paralleled each other, although mean proportion of neutrophils was significantly (P smaller than 0.05) greater in cattle affected with tarsal DJD, as were mean proportion of lymphocytes (P smaller than 0.02). Synovial fluid samples were analyzed for physical, biochemical, and cytologic properties. Statistical comparisons were made between values determined for arthritic cattle and control cattle. All samples from cattle with tarsal DJD were transudative. Opacity and flocculation were attributed to the presence of cartilaginous fragments and fibrils. There was significant correlation between increased relative viscosity (RV) and higher grades of mucinous precipitate quality (MPQ; r = +0.294, P smaller than 0.05) for all cattle. Mean alkaline phosphatase (ALP) activity for arthritic cattle was significantly (P smaller than 0.001) reduced, as was the mean activity for lactic dehydrogenase (LDH; P smaller than 0.05). The mean aldolase (ALD) activity for arthritic cattle was increased, whereas mean activity values for glutamic oxalacetic transaminase (GOT) and glutamic pyruvic transaminase (GPT) were reduced. Samples from arthritic cattle had reduced total leukocyte counts and significantly (P smaller than 0.05) increased proportion of macrophages in comparison to the values in control cattle.     

Variability of resistance in goats infected with Haemonchus contortus in Brazil

The variability between and within breeds with respect to nematode egg counts (EPG), packed cell volume (PCV) and hemoglobin (Hb) was studied in 36 yearling female goats of the Caninde (15), Bhuj (6) and Anglo-Nubian (15) breeds, exposed to Haemonchus contortus. Nematode-free goats were turned to a contaminated paddock in late February. From then on, fecal egg per gram counts (EPG), packed cell volume (PCV) and hemoglobin (Hb) were determined at 2-week intervals up to Week 18. The EPG, transformed as [log(EPG + 75)], varied (P < 0.01) between goats within breeds and between weeks of exposure, but not between goat breeds (P > 0.05). PCV and Hb were affected by goat breeds (P < 0.05), by goats within breeds (P < 0.01) and by weeks of exposure (P < 0.01). Anglo-Nubians had higher (P < 0.01) PCV and Hb than Caninde; Bhuj had intermediate values. There were two EPG rises; one between Weeks 6 and 10 and the other between Weeks 14 and 16. The within breed variability was marked during the EPG rise on Week 6, when individual egg counts ranged from 130 to 2500. The EPG rises coincided with drops in Hb. PCV presented a similar trend, though not as marked. Haemonchus was responsible for more than 95% of nematode eggs counted. Considering the goat as experimental unit, the correlation coefficients (r) were: -0.45, P = 0.0064, between log(EPG + 75) and PCV; and -0.53, P = 0.0009, between log(EPG + 75) and Hb. The negative correlation between egg counts and blood values suggested breed differences in PCV and Hb were related to resistance to H. contortus infection and/or to its effects.     

Use of blood and blood products.

It is sometimes necessary for the practitioner to transfuse the ruminant with whole blood or plasma. These techniques are often difficult to perform in practice, are time-consuming, expensive, and stressful to the animal. Acute loss of 20% to 25% of the blood volume will result in marked clinical signs of anemia, including tachycardia and maniacal behavior. The PCV is only a useful tool with which to monitor acute blood loss after intravascular equilibration with other fluid compartments has occurred. An acutely developing PCV of 15% or less may require transfusion. Chronic anemia with PCV of 7% to 12% can be tolerated without transfusion if the animal is not stressed and no further decline in erythrocyte mass occurs. Seventy-five percent of transfused bovine erythrocytes are destroyed within 48 hours of transfusion. A transfusion rate of 10 to 20 mL/kg recipient weight is necessary to result in any appreciable increase in PCV. A nonpregnant donor can contribute 10 to 15 mL of blood/kg body weight at 2- to 4-week intervals. Sodium citrate is an effective anticoagulant, but acid citrate dextrose should be used if blood is to be stored for more than a few hours. Blood should not be stored more than 2 weeks prior to administration. Heparin is an unsuitable anticoagulant because the quantity of heparin required for clot-free blood collection will lead to coagulation defects in the recipient. Blood cross-matching is only rarely performed in the ruminant. In field situations, it is advisable to inject 200 mL of donor blood into the adult recipient and wait 10 minutes. If no reaction occurs, the rest of the blood can probably be safely administered as long as volume overload problems do not develop. Adverse reactions are most commonly seen in very young animals or pregnant cattle. Signs of blood or plasma transfusion reaction include hiccoughing, tachycardia, tachypnea, sweating, muscle tremors, pruritus, salivation, cough, dyspnea, fever, lacrimation, hematuria, hemoglobinuria, collapse, apnea, and opisthotonos. Intravenous epinephrine HCl 1:1000 can be administered (0.2 to 0.5 mL) intravenously or (4 to 5 mL) intramuscularly (preferable) if clinical signs are severe. Pretreatment with antipyretics and slowing the administration rate may decrease the febrile response. Blood or plasma administered too rapidly will also result in signs of cardiovascular overload, acute heart failure, and pulmonary hypertension and edema. Furosemide and slower administration of blood or plasma should alleviate this problem. Administration rates have been suggested starting from 10 mL/kg/hr; faster rates may be necessary in peracute hemorrhage. Plasma should be administered when failure of absorption of passive maternal antibody has occurred or when protein-loosing enteropathy or nephropathy results in a total protein of less than 3 g/dL or less than 1.5 g albumin/dL. Plasma can be stored at household freezer temperatures (-15 to -20 degrees C) for a year; coagulation factors will be destroyed after 2 to 4 months when stored in this manner. To maintain viability of coagulation factors, plasma must be stored at -80 degrees C for less than 12 months. When administering plasma, a blood donor set with a built-in filter should always be used. When bovine plasma is thawed, precipitants form in the plasma and infusion of these microaggregates may result in fatal reactions in the recipient.     

Effect of vaccination of boars against porcine circovirus type 2 on ejaculate characteristics, serum antibody titers, viremia, and semen virus shedding

The objective of this research was to determine the effect of vaccination against porcine circovirus type 2 (PCV2) on ejaculate characteristics, PCV2-specific antibody titers in serum, viremia, and viral shedding in the semen of PCV2-positive boars. Before vaccination, all boars were confirmed by PCR to be naturally infected with PCV2. The boars were vaccinated with a commercial killed vaccine against PCV2 (n = 5) or served as controls and received 2 mL of 0.9% saline (n = 5). Semen and blood samples were collected before vaccination at wk 0 and at 7-d intervals thereafter until wk 8. Sperm concentration and characteristics of sperm motility were assessed using a computer-assisted sperm analysis system, and sperm morphology was evaluated using light microscopy after staining. The PCV2 antibody titers were determined in serum using an ELISA, and the genomic copy numbers of PCV2 DNA in serum and semen were determined by real-time PCR. In general, there were no effects of treatment or treatment × week on semen or sperm characteristics (P > 0.10). An effect of treatment × week was detected for serum antibody titers (P < 0.01). Compared with controls, PCV2 antibody titers in vaccinated boars were less (P < 0.01) at wk 7 (1.01 ± 0.05 titer/mL vs. 1.23 ± 0.05 titer/mL) and tended (P = 0.07) to be less at wk 8 (1.05 ± 0.05 titer/mL vs. 1.17 ± 0.05 titer/mL). There were no effects of treatment or treatment × week for serum and semen genomic copy numbers of PCV2 DNA (P > 0.10). There was a tendency (P = 0.09) for an effect of week on serum viral load. It was evident that during this experiment, boars experienced reoccurring PCV2 infection, and the detection of an increased PCV2 DNA load in serum preceded that in semen; the duration of reoccurring infection appeared to be less in vaccinated boars compared with controls. In summary, vaccination against PCV2 can reduce antibody titers when given postinfection and has no dramatic effect on indicators of semen quality. Vaccination against PCV2 in naturally infected boars can also decrease the length of reoccurring infection and decrease the duration of viral shedding in semen.     

果寡糖对固始鸡血液生理指标的影响

本试验旨在研究不同添加剂量的果寡糖对固始鸡血液生理指标的影响,并确定果寡糖的最佳添加剂量。选用1日龄固始鸡公雏150只,随机分成5个处理组,1个为对照组,其余4个为试验组,对照组不加果寡糖,其他4个组的果寡糖添加水平分别为3、5、7mg/kg和9mg/kg。测定红细胞压积(PCV)、血红蛋白(Hb)含量、红细胞数量、白细胞数量、平均红细胞体积(MCV)、平均红细胞血红蛋白含量(MCH)和平均红细胞血红蛋白浓度(MCHC)等指标。试验结果表明:1)21和42日龄时,果寡糖试验组的红细胞压积、血红蛋白含量、红细胞数量和白细胞数量均显著高于对照组(P<0.05);与对照组相比,试验组的MCH和MCHC均略有升高,并且可以显著提高MCHC(P<0.05);2)日粮中添加5mg/kg果寡糖对提高红细胞压积、血红蛋白含量、红细胞数量、白细胞数量、MCH和MCHC具有最佳效果。     

Use of blood and blood products

It is sometimes necessary for the practitioner to transfuse the ruminant with whole blood or plasma. These techniques are often difficult to perform in practice and are time-consuming, expensive, and stressful to the animal. Acute loss of 20-25% of the blood volume will result in marked clinical signs of anemia, including tachycardia and maniacal behavior. The PCV is only a useful tool with which to monitor acute blood loss after intravascular equilibration with other fluid compartments has occurred. An acutely developing PCV of 15% or less may require transfusion. Chronic anemia with PCV of 7-12% can be tolerated without transfusion if the animal is not stressed and no further decline in erythrocyte mass occurs. Seventy-five per cent of transfused bovine erythrocytes are destroyed within 48 hours of transfusion. A transfusion rate of 10-20 ml/kg, recipient weight, is necessary to result in any appreciable increase in PCV. A nonpregnant donor can contribute 10-15 ml of blood/kg body weight at 2-4 week intervals. Sodium citrate is an effective anticoagulant, but acid citrate dextrose should be used if blood is to be stored for more than a few hours. Blood should not be stored more than 2 weeks prior to administration. Heparin is an unsuitable anticoagulant because the quantity of heparin required for clot-free blood collection will lead to coagulation defects in the recipient. Blood crossmatching is only rarely performed in the ruminant. In field situations, it is advisable to inject 200 ml of donor blood into the adult recipient and wait 10 minutes. If no reaction occurs, the rest of the blood can probably be safely administered as long as volume overload problems do not develop. Adverse reactions are most commonly seen in very young animals or pregnant cattle. Signs of blood or plasma transfusion reaction include hiccoughing, tachycardia, tachypnea, sweating, muscle tremors, pruritus, salivation, cough, dyspnea, fever, lacrimation, hematuria, hemoglobinuria, collapse, apnea, and opisthotonos. Intravenous epinephrine HCl 1:1000 can be administered (0.2 to 0.5 ml) intravenously or (4 to 5 ml) intramuscularly if clinical signs are severe. Pretreatment with antipyretics and slowing the administration rate may decrease the febrile response. Blood or plasma administered too rapidly will also result in signs of cardiovascular overload, acute heart failure, and pulmonary hypertension and edema. Furosemide and slower administration of blood or plasma should alleviate this problem.(ABSTRACT TRUNCATED AT 400 WORDS)     

Analysis of feline,canine and equine hemograms using the QBC VetAutoread

Blood samples form 120 consecutive clinical cases (40 cats, 40 dogs and 40 horses) were analyzed on the QBC VetAutoread analyzer and the results compared with those obtained by a Baker 9000 electronic resistance cell counter and a 100-cell manual differential leukocyte (WBC) count. Packed cell volume (PCV), hemoglobin (Hb) concentration, mean cell hemoglobin concentration (MCHC), and platelet, total WBC, granulocytes, and lymphocyte plus monocyte (L+M) counts were determined. Indistinct separation of red blood cell and granulocytes layers on the QBC VetAutoread was observed in samples from five cats (12.5%), two dogs (5%), and one horse. Significantly different (P=0.002) median values for the two methods were obtained for PCV, Hb concentration, MCHC and platelet count in cats; PCV, MCHC, WBC, count and granulocytes count in dogs; and PCV, Hb concentration, MCHC and WBC, granulocytes and platelet counts in horses. Results from the QBC VetAutoread should not be interpreted using reference ranges established using other equipment. Results were abnormal on a limited number of samples; however, when correlation coefficients were low, marked discrepancy existed between values within as well as outside of reference ranges. Spearman rank correlation coefficients were excellent (r=0.93) for PCV and Hb concentration in dogs, and Hb concentration and WBC count in horses. Correlation was good (r=0.80-0.92) for PCV and Hb concentration in cats, WBC count in dogs, and PCV, granulocytes count and platelet count in horses. For remaining parameters, correlation was fair to poor (r=0.79). Acceptable correlations (r>0.80) were achieved between the two test systems for all equine values except MCHC and L+M count, but only for PCV and HB concentration in feline and canine blood samples.     

The haematological examination of canine blood samples received by post: the influence of delay in examination on red cell parameters

The mean packed cell volume (PCV) for canine blood samples received by post was significantly higher than that for fresh samples, at each haemoglobin value over the range 9 to 19 g/dl. As a consequence the mean corpuscular volume (MCV) and the mean corpuscular haemoglobin concentration (MCHC) also differed. Apart from one Hb value there was no significant difference in the mean red blood cell (rbc) count over the Hb range 6 to 14 g/dl. It is suggested that the normal values for the PCV and MCV should be 3 to 5% and 5 to 7 f 1 higher respectively for postal samples as compared to fresh samples while the MCHC should be about 3 to 4 g/dl lower.     

Erythrocyte sedimentation rate in the dog and cat: Comparison of two methods and influence of packed cell volume, temperature and storage of blood

Erythrocyte sedimentation rates of canine and feline blood were measured by the Wintrobe method and by a capillary method utilizing 75 times 1 mm microhaematocrit tubes. Results obtained with each method were generally similar for both species.
The erythrocyte sedimentation rate (ESR) with the Wintrobe method as well as with the capillary method was inversely related to the packed cell volume (PCV), i. e., the lower the PCV, the higher the ESR. However, there was no consistent relationship between the ESR values obtained by the two methods at all levels of PCV. Wintrobe ESR values were slightly higher than capillary tube values for canine blood having a PCV of 36-60% and for 'reconstituted' canine and feline bloods having a high PCV. In contrast, capillary tube ESR values were slightly higher than Wintrobe values for 'reconstituted' canine blood having a PCV of 8-38 % and for feline blood with a PCV below 30%. It was, therefore, concluded that ESR values obtained by the two methods cannot be considered equivalent.
Only a slight decrease occurred in the ESR of blood held at 4°C for 2-6 hours, whereas the ESR of blood held at room temperature dropped markedly and blood stored for 24 hours at either temperature consistently gave lower values. Therefore, it is recommended that if the ESR cannot be determined soon after sampling, the blood should be stored at 4°C and the test conducted within 6 hours.     

The effects of a probiotic on blood urea nitrogen and creatinine concentrations in large felids

Chronic kidney disease is a common finding in older captive exotic felids. The purpose of this study was to evaluate the effectiveness of a probiotic to reduce blood urea nitrogen and creatinine in large felids. Fifteen adult, large felids (6 tigers [Panthera tigris], 5 lions [Panthera leo], 3 cougars [Puma concolor], and 1 leopard [Panthera pardus]) were administered a probiotic twice daily after a baseline complete blood cell count and plasma chemistry panel was obtained. Plasma chemistry values were rechecked at 2 mo (n = 14) and 6 mo (n = 9). There was no significant change in blood urea nitrogen over time; however, there was a significant change in creatinine over time (P = 0.04). Creatinine concentration decreased significantly between 2 and 6 mo (P = 0.02), and a decrease was seen between 0 and 6 mo, but this change was not significant (P = 0.05). There was no significant difference noted for creatinine concentration between 0 and 2 mo (P = 0.35). This probiotic may be helpful in large felids with elevated creatinine concentrations because of chronic kidney disease; however, further studies are warranted.     

Case-control study on the association of porcine circovirus type 2 and other swine viral pathogens with postweaning multisystemic wasting syndrome.

A field-based case-control study was conducted to assess the strength of association of porcine circovirus type 2 (PCV2) and some major swine viruses with postweaning multisystemic wasting syndrome (PMWS). Cases were defined as individual pigs with a clinical history of progressive weight loss and histopathological lesions characteristic of PMWS. Controls were pigs without clinical signs and histopathological lesions typical of PMWS. A total of 31 cases and 56 controls was identified from diagnostic submissions. Serum and various tissues were collected from all animals and assayed for PCV, porcine reproductive and respiratory syndrome virus (PRRSV), porcine parvovirus, porcine enterovirus types 1-3, swine influenza virus, porcine respiratory coronavirus, transmissible gastroenteritis virus, porcine endogenous retrovirus, porcine lymphotropic herpesvirus type 1, and bovine viral diarrhea virus. The proportion of case and control pigs positive for each virus was determined and statistically compared for determining the strength of the association that each virus had with PMWS individually or in combinations. Porcine circovirus type 2 had the strongest association (OR = 9.3, P = 0.006) with PMWS among the viruses tested for. Risk for PWMS was much higher (OR = 31.2, P = 0.0009) if the animal was concurrently infected with PCV2 and PRRSV, suggesting that development of PMWS may be enhanced by cofactor(s). Because PCV2 was also found in 62.5% of the controls, PCV2 from 5 cases and 4 controls were selected and genetically compared. No significant genetic difference was observed between PCV2 from PMWS and control pigs.     

Preliminary study of Porcine circovirus type 2 and Torque teno sus virus coinfection frequencies in Brazilian pig herds

Torque teno sus virus (TTSuV) is emergent in swine herds. Recent studies have shown an increased frequency of TTSuV2 in Porcine circovirus type 2 (PCV2)-associated diseases (PCVAD), which are endemic in many swine-producing countries, including Brazil. Coinfection with several other viral and bacterial agents results in an increased incidence of more severe PCVAD. Given the limited information on TTSuV and PCV2 coinfection, especially in Brazilian swine herds, this study made a preliminary estimation of the occurrence of coinfection in swine herds by testing samples from different categories. Between 2008 and 2009, 111 samples of feces and 23 serum samples from 5 swine herds were tested for PCV2 and TTSuVs and the results analyzed for associations between these agents. No significant differences in coinfection frequency were observed for PCV2 + TTSuV1 or for PCV2 + TTSuV2 between nursery piglets (P = 0.730), growing pigs (P = 0.331), or sows (P = 0.472). However, a significant difference was observed for PCV2 + TTSuV1 + TTSuV2 between nursery piglets and growing pigs (P = 0.004; Fisher’s exact test). Phylogenetic studies agreed with the grouping of TTSuV1 and TTSuV2 into 2 different clades, with no distinct pattern of clustering of these isolates with the animal categories.     

Parasitological prevalence of bovine trypanosomosis in Kindo Koisha district,Wollaita zone,south Ethiopia

A cross sectional survey to determine the distribution and prevalence of trypanosomosis was conducted in Kindo Koisha district, in the Wollaita zone in southern Ethiopia. A total of 1 008 adult cattle was examined at eight different localities. Dark field examination of the buffy coat, as well as stained thin blood film examination and packed cell volume (PCV) evaluation were the diagnostic techniques used. The overall prevalence of bovine trypanosomosis was 15 %. Among the positive animals, 108 (71.1%), 43 (28.4%) and 1 (0.6%) were due to Trypanosoma vivax, Trypanosoma congolense and mixed infection (T. vivax and T. congolense), respectively. The infection rate of T. vivax and T. congolense varied significantly (P < 0.01). The mean PCV of the positive and negative animals ranged between 18.3-32.1% and 26.8-33.4%, respectively. The mean PCV of negative animals (28 %) was significantly higher than the mean PCV of positive animals (22.3%) (P < 0.001). There was an inverse association of PCV with the prevalence of trypanosomosis (P > 0.05). The herd average PCV values of each site decreased with increasing proportion of the positive herds of that particular site. Of the diagnostic tests employed, the microhaematocrit buffy coat technique is relatively sensitive and it has an added advantage of indicating the general condition of the animal by haematocrit measurement. In view of the risk of trypanosomosis, a control intervention through the strategic application of appropriate trypanocidal drugs is recommended. A tsetse fly control scheme to reduce host-tsetse fly contact is equally as important as chemotherapy and chemoprophylaxis against trypanosomosis.     

Monocyte-derived dendritic cells enhance cell proliferation and porcine circovirus type 2 replication in concanavalin A-stimulated swine peripheral blood lymphocytes in vitro

Dendritic cells (DCs) are professional antigen presenting cells cooperating with other immune cells for the activation of innate and adaptive immune responses. The objective of the present study was to investigate the replication activity of porcine circovirus type 2 (PCV2) in DCs and/or lymphocytes during their cross talk and its possible mechanism. Two models were set, herein. Swine blood monocyte (Mo)-derived DCs (MoDCs) or peripheral blood lymphocytes (PBLs) were inoculated with PCV2 prior to their co-cultivation. Bacterial lipopolysaccharide (LPS) and concanavalin A (Con A) were used to stimulate MoDCs and PBLs, respectively. During 6 days of cultivation, a high PCV2 antigen-containing rate without detectable intranuclear signals and a slight but significant increase in the copy number of PCV2 genome were detected in PCV2-inoculated MoDCs. The presence of LPS alone or PCV2-free PBLs, however, had no effect on the location of PCV2 antigens or copy number of PCV2 genome in PCV2-inoculated MoDCs. On the contrary, active PCV2 replication occurred in Con A-stimulated PCV2-inoculated PBLs. When compared with blood Mos, MoDCs induced significantly higher cell proliferation and intensified PCV2 replication in Con A-stimulated PCV2-inoculated PBLs, for which direct contact between MoDCs and lymphocytes was required. Among the cytokines secreted by Con A-activated PBLs, interleukin (IL)-2, but not IL-4 or interferon-γ, could induce cell proliferation and PCV2 replication in PCV2-inoculated PBLs. The findings suggest that although MoDCs support only limited PCV2 replication in themselves, their accessory cell function is required for cell proliferation and PCV2 replication in PCV2-infected lymphocytes.