Evaluation of a concentration method for counting Sarcocystis gigantea sporocysts in cat faeces

A technique for determining the numbers of S. gigantea sporocysts in cat faeces using a concentration procedure and haemocytometer was evaluated. The results showed that it was more accurate than a modified McMaster method and had a mean recovery rate of 73% at four levels of infection ranging from about 2000 to over 20,000 sporocysts per gram of faeces.     

Evaluation of six cytometric methods for reticulocyte enumeration and differentiation in the cat

Six protocols utilizing three fluorescent nucleic acid dyes (thiazole orange, auramine 0, and acridine orange) were evaluated by flow cytometty for clinical utility in the analysis of feline reticulocytes. The dyes showed good to poor correlations with each other and with manual counts. Thiazole orange was the preferred stain. Thiazole orange dye showed distinct peaks corresponding to aggregate and punctate reticulocytes from specimens with marked reticulocytosis. The other dyes detected increases in reticulocyte numbers but subpopulations could not be distinguished. Standardized instrument and gate settings, applied to specimens stained with thiazole orange dye, enumerated aggregate and punctate reticulowes in low celfularity specimens that lacked distinct peaks. Percentages of these cells correlated well with manual counts, offering a simplified technique for routine laboratory use.     

An efficient procedure for manual platelet counting

Blood samples were collected by jugular venipuncture from 15 dairy heifers and the blood platelets were counted by manual methods. The platelets were found to be uniformly distributed across the rows, columns and sides of a Neubauer haemocytometer, and it was shown that counting any 10 squares on either side of the haemocytometer and multiplying by a constant factor would accurately predict the total platelet count. This procedure would greatly reduce the time required to count large numbers of platelets per sample, and reduce errors due to the fatigue associated with counting large numbers of samples.     

Evaluation of techniques for counting bovine platelets.

Visual and electronic techniques for counting bovine platelets were investigated. The reference method used was hemacytometer counting of platelets in whole blood diluted with 0.85% NaCl solution. A whole blood platelet-rich plasma technique was imprecise and inaccurate. Isopycnic centrifugation of blood diluted in 8.01% NaCl solution (same density as platelets) was a precise technique, but the whole blood platelet count was underestimated. The most precise and accurate technique investigated was unit gravity sedimentation of a 1:100 dilution of blood with 10 ml of Isoton followed by electronic counting of platelets in the supernatant. This technique correlated very well with visual counting of bovine platelets (N = 77, y = 55 + 0.80x, r = 0.89, P less than 0.01).     

猫传染性鼻气管炎PCR检测方法的建立

本文通过设计特异性扩增猫疱疹病毒Ⅰ型gD基因的引物,使用猫三联弱毒苗为模板建立了检测猫疱疹病毒Ⅰ型的PCR诊断方法,并对其灵敏性、特异性进行了评价,并将建立的PCR检测方法对临床样品进行了检测。实验结果证实,本实验建立的猫疱疹病毒Ⅰ型的PCR检测方法,其灵敏度可达到最低可检测10^5拷贝的病毒含量;特异性试验结果仅能扩增出猫三联弱毒苗。     

Evaluation of a xylazine-ketamine hydrochloride combination in the cat.

Cardiopulmonary function was assessed in healthy cats given a xylazine-ketamine hydrochloride combination intramuscularly. Cardiac output, heart rate, stroke volume and cardiac index were significantly decreased. Systolic, diastolic and mean arterial blood pressure were also significantly decreased. Systemic vascular resistance and central venous pressure were significantly increased. Blood gas values remained stable. In conclusion, significant cardiovascular depression was noted in normal cats given the xylazine-ketamine combination at the dosages listed.     

3种荧光标记根瘤菌数量测定方法比较

试验以绿色荧光蛋白标记的中华苜蓿根瘤菌菌株Sm1021为试验材料,将平板涂布法、膜过滤法、流式细胞术3种微生物计数方法测得结果进行对比,以平板涂布法为基准,观察膜过滤法与流式细胞术的准确性。结果表明:利用膜过滤法测定根瘤菌数量可获得与平板涂布法相近的结果,但在操作层面上具有一定制约,且测定成本较高,只有在某些特定情况下具有应用优势;流式细胞术测定的结果与平板涂布法所得结果间存在显著的差异,但由于菌类的数量基数较大,可进行粗略的统计估算。此外,当菌液中菌量较大时,流式细胞术的准确性增加(P=0.495)。     

Feline platelet counting with prostaglandin E1 on the Sysmex XT‐2000iV

Background: The large size of many feline platelets and the high frequency of platelet aggregation often results in falsely low platelet counts in this species. A combination of optical platelet counting to detect even large platelets and the use of prostaglandin E1 (PGE1) to inhibit platelet clumping may increase the accuracy of feline platelet counting. Objective: The objective of this study was to compare platelet counts in feline whole blood samples with and without the addition of PGE1 and using different analytical methods in a clinical setting. Methods: Platelet counts were determined in 10 feline patients in a referral veterinary hospital using 2 sample types (EDTA, EDTA with PGE1) and 2 methods of analysis (optical counting [PLT‐O] and impedance counting [PLT‐I]) on the Sysmex XT 2000 iV analyzer. Results: All PGE1–PLT‐O samples had platelet counts of >200 × 10⁹/L. Mean platelet count using PGE1–PLT‐O (410,256±178 × 10⁹/L) was significantly higher (P<.03) compared with PGE1–PLT‐I (256±113 × 10⁹/L), EDTA–PLT‐O (238±107 × 10⁹/L), and EDTA–PLT‐I (142±84 × 10⁹/L) methods. Depending on the method, platelet counts in 2 to 7 of 10 cats were <200 × 10⁹/L when PGE1‐PLT‐O was not used. A slightly increased platelet count in response to treatment of a feline patient with thrombocytopenia would have been missed without use of PGE1–PLT‐O. Conclusions: Using PLT‐O analysis on EDTA samples containing PGE1 provides higher, and therefore likely more accurate, feline platelet counts in a clinical setting.     

Accuracy of two methods for counting eggs of sheep nematode parasites

A comparative study was carried out on eight species of sheep gastrointestinal nematodes in order to compare the value of two techniques for egg counting: the classical McMaster technique with saturated magnesium sulfate solution and a technique of egg extraction from faeces and counting by total collection after three centrifugations. Efficiency of extraction from 10 g of faeces was 95.9 to 99.5% according to the species of parasite, whereas the number of eggs counted by the McMaster technique represented only 16.5% of the total eggs present in the faeces. Advantages inherent in the use of these techniques are discussed.     

Evaluation of ammonium chloride as a urinary acidifier in the cat

Twenty-four cats were fed a dry commercial cat food once daily for 2 weeks and then ad libitum for 2 weeks. Urine pH was measured 4 times daily the last 3 days of each feeding period. Subsequently, the cats were allotted to 2 equal groups and fed ad libitum an experimental, dry ration with or without 1.5% ammonium chloride for 11 months. During this period, urine pH was measured at 1, 3, 6, and 9 weeks, then monthly through 29 weeks, and then every 6 weeks for the duration of the study. When the cats were fed ad libitum, urine pH remained constant throughout the day, regardless of ration. In cats fed once daily, urine pH increased to 7.6 by 2 hours after feeding and remained between 6.6 and 7.6 for 9 hours. Urine pH remained constant throughout the study when cats were fed the experimental ration with or without 1.5% ammonium chloride, but was significantly different (P less than 0.01) between the 2 groups, 5.9 +/- 0.3 (n = 1,035) and 7.0 +/- 0.5 (n = 616), respectively. Ammonium chloride consumption had no effect on food and water consumption or body weight. It was concluded that ammonium chloride was an effective urinary acidifier for a prolonged time, maintained urine pH below 6.6, and did not decrease food intake when given at a concentration of 1.5% of the diet.     

Evaluation of platelet function in dogs with cardiac disease using the PFA‐100 platelet function analyzer

Background: Cardiac disease has the potential to alter platelet function in dogs. Evaluation of platelet function using the PFA‐100 analyzer in dogs of multiple breeds and with a broad range of cardiac conditions would help clarify the effect of cardiac disease on platelets. Objectives: The objective of this study was to assess differences in closure time (CT) in dogs with cardiac disease associated with murmurs, when compared with that of healthy dogs. Methods: Thirty‐nine dogs with cardiac murmurs and turbulent blood flow as determined echocardiographically were included in the study. The dogs represented 23 different breeds. Dogs with murmurs were further divided into those with atrioventricular valvular insufficiency (n=23) and subaortic stenosis (n=9). Fifty‐eight clinically healthy dogs were used as controls. CTs were determined in duplicate on a PFA‐100 analyzer using collagen/ADP cartridges. Results: Compared with CTs in the control group (mean±SD, 57.6±5.9 seconds; median, 56.5 seconds; reference interval, 48.0–77.0 seconds), dogs with valvular insufficiency (mean±SD, 81.9±26.3 seconds; median, 78.0 seconds; range, 52.5–187 seconds), subaortic stenosis (71.4±16.5 seconds; median, 66.0 seconds; range, 51.5–95.0 seconds), and all dogs with murmurs combined (79.6±24.1 seconds; median, 74.0 seconds; range, 48.0–187 seconds) had significantly prolonged CTs (P<.01). Conclusions: The PFA‐100 analyzer is useful in detecting platelet function defects in dogs with cardiac murmurs, most notably those caused by mitral and/or tricuspid valvular insufficiency or subaortic stenosis. The form of turbulent blood flow does not appear to be an important factor in platelet hypofunction in these forms of cardiac disease.     

Evaluation of platelet activation in canine immune-mediated haemolytic anaemia

Objectives : To establish whether heightened platelet activation is a common feature of canine immune-mediated haemolytic anaemia, and to evaluate the hypothesis that platelet activation plays a role in the pathogenesis of thromboembolism. Methods : Using whole-blood flow-cytometric analysis, the proportion of activated platelets and platelet-leucocyte aggregates in blood samples from 14 dogs with immune-mediated haemolytic anaemia and 14 healthy dogs was calculated. General linear models with binomial errors were used to compare groups. Results from the immune-mediated haemolytic anaemia-affected dogs were then correlated with established risk factors for thromboembolism in canine immune-mediated haemolytic anaemia, D-dimer concentration and antithrombin activity. Results : There was a strong correlation between platelet activation and severe thrombocytopenia, with heightened platelet activation being observed predominantly in severely thrombocytopenic dogs. Clinical Significance : Dogs with immune-mediated haemolytic anaemia, particularly those with concurrent severe thrombocytopenia, are likely to have heightened platelet activation, which may play a role in the pathogenesis of thromboembolism.     

Evaluation of platelet additive solution for prolonging storage of functional canine platelet concentrate

Objective

To assess storage lesion development, platelet function, and bacterial growth in canine platelet concentrates (PCs) stored in a platelet additive solution (PAS) or a plasma control at 4°C for 21 days.

Design

Prospective, ex vivo, experimental controlled study.

Setting

University veterinary teaching hospital.

Animals

Ten units of canine PCs collected from blood bank donations.

Interventions

The PCs were separated into 2 bags, 1 containing 100% plasma and the other containing 35% plasma and 65% of a PAS (Plasma-Lyte A), and stored at 4°C for 21 days. At days 0, 7, 14, and 21, PCs were analyzed for the presence of swirling, aggregate formation, platelet counts, platelet indices, glucose, lactate, lactate dehydrogenase, Pvco ₂, Pvo ₂, aggregation via light aggregometry, activation percentages using flow cytometry, and bacterial growth.

Measurements and main results

Cold-stored PCs in both PAS and plasma control maintained mean pH >6.8 and mean lactate <9.0 mmol/L over 21 days, with no difference in glucose utilization. Swirl was maintained in both solutions for most days (76/80 combined total samples), with no difference in aggregate formation between solutions. The Pvco ₂ was higher in plasma on all days (P < 0.001), with no difference in Pvo ₂. Platelet indices did not reflect significant storage lesion development in either solution. Lactate dehydrogenase did not differ between solutions but did increase from day 7 to day 21. Mean maximal aggregation percentage was reduced overall but with no significant difference between solutions. The only observed difference in mean activation percentage between solutions was in PAS on day 7, which was significantly higher than plasma (P < 0.05). No bacterial growth occurred during storage.

Conclusions

Cold storage in PAS and plasma allowed PCs to be stored for up to 21 days with minimal storage lesion development, maintenance of platelet function, limited platelet activation, and no bacterial growth within stored bags.