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1.
P A Gentry 《Canadian journal of veterinary research》1984,48(1):58-62
Factor XI protein, isolated from normal bovine plasma, was used to raise antiserum in rabbits. The antisera was partially purified and used in a neutralization-inhibition assay to investigate the relationship between factor XI coagulant activity and antigenic material in the plasma of normal cattle and cattle homozygous and heterozygous for factor XI deficiency. Factor XI antigen was reduced in both the homozygous and heterozygous animals to levels comparable to the factor XI coagulant activity. The reduction of immunologically cross-reactive material to normal factor XI suggests that the factor XI coagulation defect is associated with the absence of a normal protein. 相似文献
2.
Coagulation factor XI deficiency in Holstein cattle: expression and distribution of factor XI activity. 
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下载免费PDF全文 Factor XI (F XI) is a plasma protein that participates in the blood coagulation process. A study of the expression of F XI activity in Holstein cattle has confirmed that the inheritance of F XI deficiency is autosomal with severe deficiency in homozygotes (mean F XI level 2%, SD 1%), and partial deficiency in heterozygotes (mean F XI level 38%, SD 10%; normal mean F XI level 94%, SD 21%). In a total of 1469 males evaluated for F XI levels, 47 or 3.1% were identified as heterozygous and only one as homozygous for the disorder. In part because of the lack of a discrete distinction in the expression of F XI between heterozygous and normal animals, not all of the animals tested could be uniquely classified on the basis of the plasma F XI values. A mean F XI value of 53% (SD 7%) was found in a group of animals that were categorized as low normal/high heterozygous. If this group of cattle had been classified on the basis of the criterion used to classify human beings then these animals would have been categorized as heterozygous since the mean F XI value for proven bovine heterozygotes is approximately 20% lower than the values found in the human counterpart. Like the human form of the disease, however, there appears to be a low frequency of hemorrhagic episodes associated with F XI deficiency in cattle. 相似文献
3.
Factor XI deficiency was detected in Holstein cows and mummified foetuses in Japan; however, no report is available about the occurrence of Factor XI deficiency in Holstein semen in Japan. Five hundred cows in twelve dairy farms in Hiroshima Prefecture, Japan were under the study. Genomic DNA was extracted from the cows using a commercial DNA kits and screened to Factor XI mutation. Based on the information of the carrier cows found in the cattle population, four Holstein bulls were analysed for Factor XI mutation. DNA was extracted from bull's semen using phenol chloroform method. Extracted genomic DNA of the bull's semen was typed for Factor XI using specific polymerase chain reaction (PCR) primers. The resultant PCR was sequenced using big dye terminator sequencing method. The pedigree of the bulls was investigated. Furthermore, the inheritance of Factor XI mutation to next generation was estimated. Out of the 500 cows, five were heterozygous to Factor XI. Moreover, out of the four bulls, one was found to carry the mutation of Factor XI; it was also a complex vertebral malformation (CVM) carrier. In DNA sequencing, the insertion mutation of 76 bp of poly-adenine that characterizes the Factor XI deficiency was detected in the carrier bull as well as the carrier cows. Pedigree analysis of the carrier bull revealed that his father and mother ID were 2247419A and 14189172A, respectively, that originated from USA Holstein. Out of six daughter cows born to the carrier bull, one cow (16.6%) inherited Factor XI mutation, while three of them (50.0%) inherited CVM mutation. Autosomal recessive genes that affect cow's reproduction have a particular concern to dairy industry. To our knowledge this is the first report of Factor XI mutation in Holstein semen in Japan. 相似文献
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5.
The coagulation parameters of a litter of kittens born to an obligate carrier of haemophilia A (classical haemophilia, factor VIII deficiency) are described. Three of four kittens were found to have an intrinsic coagulation defect, but only one was haemophilic. Factor XII deficiency was confirmed in one female, the other female and the dam being carriers of the defect. A confirmed haemophilic male from a previous litter was also found to be a factor XII deficient carrier. 相似文献
6.
Ghanem ME Nishibori M Nakao T Moriyoshi M 《The Journal of reproduction and development》2005,51(3):347-352
Genomic DNA extracted from bovine mummified tissue is valuable material for detection of some genes that may contribute to fetal abnormalities. In this study bovine genomic DNA was extracted from the hardened tissue samples of ten bovine mummified fetuses. The amount of genomic DNA extracted from 2 g of the mummified tissues by the phenol/chloroform-ethanol method was low (less than 4 microg/ml) for all samples. The extracted DNA was then amplified by the GenomiPhi DNA amplification system. After amplification, the amount of DNA was increased to more than 100 microg/ml for all samples. This amplification system was shown to be a good tool for amplifying the genomic DNA of the mummified fetuses. The amplified genomic DNA was used for testing the mummies for Factor XI gene deficiency, an autosomal recessive deficiency involved in the early stages of the intrinsic blood coagulation pathway. Exon 12 of the Factor XI gene of the mummies was amplified by PCR. Two of the ten mummified fetuses were heterozygous for the Factor XI gene as indicated by the presence of two amplified DNA fragments of 320 bp and 244 bp. Factor XI deficiency has already been described in Holstein cattle. However, no report is available for bovine fetus. In this study, DNA was extracted and amplified from the bovine mummified fetuses, and the samples were successfully tested for Factor XI gene deficiency in the mummies. 相似文献
7.
Stefan W. Hart Ingo Nolte DVM Phd 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》1994,8(5):355-362
The hemostatic function of 40 feline immunodeficiency virus (FlV) seropositive and 8 FIV and feline leukemia virus (FeLV) seropositive cats was evaluated and compared with reference values from 30 clinically healthy cats. The FIVpositive cats were divided into 3 groups: group I included asymptomatic carriers; group II comprised sick FIV-infected cats with illnesses not likely to influence the hemostatic system; and group III included FIV-positive cats with diseases potentially associated with coagulopathies. Platelet counts in FIV/FeLV-infected cats were significantly lower than in healthy cats (P < .003), whereas the differences in the 3 groups of FIV-positive cats were variable (group I, P= .009; II, P= .05; III, P= .09). Thrombocytopenia (< 145,000 platelets/μL) was present in 4 FIV-positive and 3 FIV/FeLV-positive cats. Platelet aggregation induced by collagen (0.5 and 0.25 μg/mL), adenosine diphosphate (ADP) (1 and 0.6 μmol/L), and thrombin (0.4 and 0.25 IU/mL) was not significantly different from that of healthy cats. The plasma coagulation system was evaluated by measuring one-stage prothrombin time (OSPT), activated partial thromboplastin time (APTT), thrombin time, fibrinogen concentration, coagulation factor assays, fibrinogen and fibrin degradation products (FDP), and plasma exchange test. The OSPT was similar in FlV-seropositive cats and in the healthy control group. Cats with FIV infection, however, had markedly shorter clotting times than healthy cats when using a modified test system (P < .05). In all groups of FIV-infected cats and in those with FIV/FeLV infection, APTT measured with 2 different commercially available tests, and a modified plasma assay was markedly prolonged compared with healthy cats (APTT1 and 2:3 modification: P < .01; APTT2: P < .05 except group III). In 22 of 40 cats with FIV and in 5 of 8 cats with FIV/FeLV infection, plasma samples were beyond the reference range. The thrombin time was also significantly prolonged in cats with FIV and FIV/FeLV infection (P < .01); values in 17 of 40 FIV-positive cats were above reference range. The mean fibrinogen concentration of cats with FIV and FIV/FeLV infection was higher than in the healthy control group (P < .001). Factor VIII activity of 4 cats with FIV infection was 1.5 times higher than that of healthy cats. Factor XII activity of 3 cats from a group of 20 cats with prolonged APTT was between 20% and 35%. Factor IX and XI activities ranged between 70% and 120%. The markedly prolonged APTT in 2 FIV-positive cats could be shortened considerably in a plasma exchange test using 20% feline pooled plasma. The alterations in the coagulogram of FIV-seropositive cats were not related to a clinical stage or concurrent diseases. A definite explanation of the distinct disorder within the intrinsic plasma coagulation system in FIV-infected cats was not found. 相似文献
8.
Changes in blood coagulation parameters were followed in four red deer (Cervus elaphus) experimentally infected with malignant catarrhal fever (MCF) of deer. Blood platelet counts, activated partial thromboplastin time (APTT), one-stage prothrombin time (OSPT), activated clotting time (ACT), plasma anti-thrombin III (ATIII) activity, fibrinogen degradation production (FDP) and fibrinogen levels were measured. Inoculated deer became pyrexic after 17 or 19 days. Thereafter they developed watery diarrhoea which rapidly became haemorrhagic. The course of the clinical disease ranged from four to six days before the animals were killed or died. All inoculated deer developed abnormalities in laboratory parameters of blood coagulation. These varied within and between animals, but the coagulation profiles of all four animals remained abnormal until death. Post-mortem findings included extensive systemic petechiation, severe haemorrhage in the alimentary canal and vasculitis with disseminated thrombosis. Abnormal coagulation parameters included extension of APTT and OSPT, increased FDP, decreased ATIII and platelet counts and increased fibrinogen levels. The increases in fibrinogen were compatible with the acute phase response. The other coagulation abnormalities and haemorrhage and thrombosis were indicative of disseminated intravascular coagulation (DIC) with consumption coagulopathy, ACT remained normal in all deer although final clot quality was considered poor. 相似文献
9.
OBJECTIVE: To evaluate a bench-top coagulation analyzer for determination of prothrombin time (PT), activated partial thromboplastin time (APTT), and fibrinogen concentration in healthy dogs. ANIMALS: 55 healthy adult dogs. PROCEDURES: PT, APTT, and fibrinogen concentration were determined by use of the coagulation analyzer. Values were compared with results obtained independently by a conventional laboratory. RESULTS: Correlations (with 95% confidence intervals) between the coagulation analyzer and conventional laboratory values were 0.760 (0.610 to 0.857), 0.700 (0.448 to 0.721), and 0.896 (0.878 to 0.918) for PT, APTT, and fibrinogen concentration, respectively. Using linear regression, comparison of data from the coagulation analyzer and the conventional laboratory provided equations relating the coagulation analyzer values with values from the conventional laboratory and suggested that APTT and fibrinogen values from the coagulation analyzer and conventional laboratory were approximately the same within expected random variation. Prothrombin time values for the coagulation analyzer were significantly offset from the PT values for the conventional laboratory but still were correlated reasonably well with the conventional laboratory values. CONCLUSIONS AND CLINICAL RELEVANCE: By use of the mechanical method of analysis, fibrinogen concentrations obtained with a bench-top coagulation analyzer correlated well with results for a conventional laboratory, indicating that the coagulation analyzer is a reliable instrument for determination of this coagulation variable. Coagulation analyzer results for PT and APTT correlated less strongly with those for the conventional laboratory, but they would still be considered clinically reliable. 相似文献
10.
The objective of this study was to investigate the relationship between different screening tests of haemostasis and amidolytic plasma activities of unfractionated (standard) heparin in dogs. Different doses of intravenous (i.v.) [25, 50 or 100 IU Kg(-1)bodyweight (BW)] and subcutaneous (s.c.) heparin (250, 500 and 750 IU kg(-1)) were given to groups each of five clinically healthy adult beagles. Measurements of heparin activity with a factor Xa-dependent chromogenic substrate, activated partial thromboplastin time (APTT) (two different reagents), thrombin time (TT, two different thrombin activities in the reagent: 3 and 6 IU ml(-1)) and the reaction time of the resonance thrombogram (RTG -r) with two different measuring devices were performed at different times. The relationship between ratio values (actual/baseline values) of the coagulation tests and heparin activity was analysed based on regression analysis and correlation coefficient.The greatest alterations were seen for the TT([3 IU ml(-1)])and the RTG -r which were near or exceeded the upper limit of measuring range, if 25 IU kg(-1)BW heparin were given i.v. at heparin plasma levels of 0.54 +/- 0.13 IU ml(-1). These results show, that only APTT and TT measured with high thrombin activity assay appear suitable for guiding high dose heparin therapy in dogs. Averaged alterations of APTT ratio in canine plasma were less than those observed in people for similar plasma heparin levels, indicating that the guideline extrapolated from people for monitoring high dose heparin therapy using APTT may not be valid for use in dogs.After coagulation times had been converted into ratio values, based on regression analysis and Wilcoxon's test, differences of heparin sensitivity were found not only for TT measured with different thrombin activities but also for different APTT reagents (P < 0.001). The correlation between amidylotic antifactor Xa activity and ratio of coagulation times was only moderate and found to be lower for RTG -r (instrument 1: r(s)= 0.711; instrument 2: r(s)= 0.573) than for the other coagulation tests (r(s)= 0.822 to r(s)= 0.890). This indicates a considerable variability of the ratio values of the screening tests at defined heparin plasma activities. These results show, that blood coagulation tests in general are little or unsuitable for heparin antifactor-Xa activity control. 相似文献
11.
The purpose of the study was to evaluate haemostatic function in cattle with abomasal displacement (AD) and to reflect the occurrence of disseminated intravascular coagulation (DIC). Ten adult cattle with left displacement of abomasum (LDA) (group I), 10 adult cattle with right displacement of abomasum with volvulus (RDA) (group II) and 10 clinically healthy adult cattle (control group) were used as material. Numbers of platelets (PLT) and coagulation tests (activated partial thromboplastin time (APTT), prothrombin time (PT), thrombin time (TT), serum fibrin/fibrinogen degradation products (FDPs), fibrinogen) were measured before the surgical treatment of cattle with LDA and RDA. APTT was prolonged only in group II compared with the control and group I (p<0.05). However, when the individual values of coagulation profiles of each cow were evaluated, two cattle in group I and three cattle in group II had at least three abnormal coagulation profiles, which reflect the occurrence of DIC. These cattle died after surgical treatment. The two cattle with LDA had abnormal APTT, FDPs and PLT values; three cattle with RDA had abnormal APTT, PT, TT, FDPs and PLT values. APTT (5 cases), FDPs (5 cases) and thrombocytopenia (5 cases) were the three most common abnormal tests on coagulation profile in the cattle with LDA and RDA. The results of the study indicate that cattle with AD had a spectrum of haemostatic dysfunction and that DIC was a significant risk factor for mortality. 相似文献
12.
Kummeling A Teske E Rothuizen J Van Sluijs FJ 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》2006,20(6):1319-1326
BACKGROUND: Serious postoperative hemorrhage has been reported in dogs after closure of congenital portosystemic shunts (CPS). HYPOTHESIS: In dogs with portosystemic shunting, low coagulation factor activity is responsible for coagulopathy, which can cause complications after surgery. ANIMALS: Thirty-four dogs with CPS and 39 healthy dogs. METHODS: In a prospective study, coagulation times, platelet count, and the activity of 8 coagulation factors were measured in dogs before and after surgical shunt attenuation and in 31 healthy dogs. The effect of abdominal surgery on hemostasis was determined at ovariectomy in 8 healthy dogs. RESULTS: Dogs with CPS had lower platelet counts, lower activity of factors II, V, VII, and X, and increased factor VIII and activated partial thromboplastin time (APTT) compared to healthy dogs. After surgical attenuation, dogs with CPS had decreased platelet counts and activity of factors I, II, V, VII, IX, X, and XI and a prolonged prothrombin time (PT). Ovariectomy resulted in decreased activity of factors VII and X. Six weeks after surgery, portosystemic shunting persisted in 9 of 30 dogs, with no improvement of hemostatic values. CPS dogs without shunting had improved coagulation times and increased activity of factors II, V, VII, and X. CONCLUSIONS AND CLINICAL IMPORTANCE: Dogs with CPS have lower activity of clotting factors compared to healthy dogs, resulting in a prolonged APTT. Surgical attenuation of the shunt results in increased abnormalities in coagulation times and factors immediately after surgery. Hemostasis is normalized after complete recovery of shunting after attenuation, in contrast to dogs with persistent shunting. 相似文献
13.
Mischke R 《Berliner und Münchener tier?rztliche Wochenschrift》1999,112(10-11):394-399
In the present study, six commercial reagents for the determination of the activated partial thromboplastin time (APTT) were compared with respect to their factor VIII:C and factor IX sensitivity for measurements of canine plasma. For this purpose, plasma with different levels of factor VIII:C or factor XI activity (100, 80, 70, 60, 50, 40, 30, 20, 15, and 10% [factor VIII:C: additionally 5%]) was prepared by mixing pool plasma with plasma of dogs with haemophilia A or B. Double measurements of three different sample mixtures were carried out for each activity level. The sensitivity of the reagents was measured first based on the ratios of the coagulation time to the 100% values. In addition, the single factor activity (F VIII:C/IX(X0.975)), whose accompanying APTT corresponded to the upper limit of the reference range (97.5%-quantile, n = 50) of the respective reagent, was determined graphically. The APTT reflected a decrease of factor IX activity generally more sensitive than a reduction of factor IX activity of an identical degree. Based on ratios distant differences respecting factor VIII:C and factor IX sensitivity were found between different reagents using two way analysis of variance (p < 0.05). Significant differences between various reagents were also found with respect to the F VIII:C(X0.975) and the F IX(X0.975). These corresponded to values between 27 and 50% or 32 and 64%, respectively, dependent on the reagent. As a result, the more sensitive reagents fulfilled the demands on the sensitivity of APTT in humans. Based on the latter criterion the highest sensitivity for both factors was found for the same reagent (Pathromtin) consisting of kaolin as a contact activator and human placental phospholipid. Respecting all proofed reagents, however, no relation was found between contact activator and single factor sensitivity. 相似文献
14.
Ghanem ME Nishibori M Nakao T Nakatani K Akita M 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2005,67(7):713-715
Factor XI deficiency is an autosomal recessive coagulopathy in Holstein cattle. Affected cows have a tendency to show repeat breeding. Forty repeat breeding Holstein Friesian cows were selected and tested for the Factor XI mutation. Genomic DNA was isolated from the blood of the cows (n=40). Exon 12 of the Factor XI gene of the cows was amplified by PCR. One repeat breeding cow was heterozygous to the Factor XI mutation as indicated by the presence of two DNA fragments of 320 bp and 244 bp. The insertion of the 76 bp in the heterozygous cow was confirmed by DNA sequencing. The heterozygous cow was in her fourth lactation. She gave birth to male twins at the last calving. She was inseminated artificially four times after the last calving. Factor XI deficiency in cattle has been reported in different countries. However, no case was reported in Japan. This might be the first to report Factor XI mutation in Holstein cattle in Japan. 相似文献
15.
P A Gentry L A Cheryk R D Shanks R Healey 《Canadian journal of veterinary research》1997,61(2):128-133
An inherited bleeding disorder, resembling Simmental hereditary thrombopathy (SHT), has been identified in a Simmental crossbred herd. In an affected bull calf, initially evaluated because of excessive bleeding from a vaccination site, the platelet aggregation response to the agonist, adenosine-diphosphate (ADP) was essentially absent and the aggregation response to platelet activating factor (PAF16) was reduced by at least 70%. The initial laboratory assessment of platelet function in the dam and sire yielded results which were within normal limits. The sire was not available for further testing. The dam, also a daughter of this sire, was subsequently shown to have a partially reduced aggregation response to ADP. Of 18 other offspring of the sire evaluated, 6 were also identified as having a partially impaired aggregation response. The maximum aggregation response to ADP and PAF16 in these 6 calves was approximately 50% of the level exhibited by unaffected animals. In contrast, the coagulation profiles were normal for all animals except for a heifer calf which also exhibited a partially impaired aggregation response. The plasma level of the coagulation protein, factor XI, was reduced in this heifer calf which suffered a fatal hemorrhage following dehorning. This report appears to be the 1st to have identified animals putatively heterozygous for SHT on the basis of the in vitro platelet aggregation response to ADP. 相似文献
16.
Nakata M Sakai M Sakai T 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2006,68(11):1223-1224
A crossbred Maltese dog, 6-year-old, male, was presented to us for examination due to coagulopathy. On examination of blood coagulation screening tests, activated partial thromboplastin time (APTT) was markedly prolonged (63.6 sec). Therefore, a defect in the intrinsic pathway of coagulation was suspected. An additional serum test was also examined and APTT was returned to within the normal range. Furthermore, factor IX coagulation activity was markedly low (2.3%). On the basis of these results, the dog was diagnosed with hemophilia B. The dog has since been presented to us because of hemorrhage problems again after 5, 10, and 16 months, but blood transfusions have maintained good control of its coagulopathy for more than two years. 相似文献
17.
Prekallikrein deficiency in a family of Belgian horses 总被引：1，自引：0，他引：1
R J Geor M L Jackson K D Lewis P B Fretz 《Journal of the American Veterinary Medical Association》1990,197(6):741-745
A 7-year-old Belgian stallion hemorrhaged excessively after castration; the hemostatic mechanism was investigated. The horse had normal one-stage prothrombin time and markedly prolonged activated partial thromboplastin time (APTT). Results of intrinsic coagulation factor assays were all normal with the exception of prekallikrein activity, which was markedly reduced (less than 1% activity; value for control population, 63 to 150%). Two of this horse's full siblings, a brother and sister, had markedly prolonged APTT and low prekallikrein values (2.5% and less than 1%, respectively). The addition of plasma from a normal equine plasma pool corrected the prolonged APTT in the 3 Belgian sibling with low prekallikrein activity. Prekallikrein activity in 10 other closely related Belgian horses ranged between 12.5 and 64% (mean, 29.3%), compared with 63 to 150% (mean, 91%) in 10 mixed-breed horses. In the 3 Belgian siblings with low prekallikrein activity, the APTT approached normal after prolonged incubation (15 minutes) with the contact activator and in response to addition of an ellagic acid activator. The 3 Belgian siblings with low prekallikrein activity may be homozygous for prekallikrein deficiency, whereas the other close relatives may be heterozygous for the genetic defect. 相似文献
18.
The aim of the study was to examine how activated partial thromboplastin time (APTT, two different reagents), thrombin time (TT, thrombin activity in the reagent: 3 or 6 IU ml(-1)) and reaction time of the resonance thrombogram (RTG-r) in healthy dogs are influenced by low molecular weight heparin (LMWH). Three different LMWH doses were given subcutaneously or intravenously to groups, each of five healthy dogs. Mean plasma anti-FXa activities of 0.43, 0.88 and 1.86 anti-FXa IU ml(-1)were measured 2 min after intravenous injection of 25, 50 or 100 anti-FXa IU kg(-1). At this time, a dose-dependent increase of the coagulation times, above the baseline values (P < 0.05), was observed for all haemostatic tests. The significant prolongation of coagulation time lasted 10 minutes to 3 hours, and it was dependent on the test employed and LMWH dose. After subcutaneous LMWH injection of 50, 100 and 200 anti-FXa IU kg(-1), significant changes of the coagulation time above initial values were limited to the period around the time when maximum anti-FXa activities (0.23, 0.43 or 0.90 anti-FXa IU ml(-1)) were observed. For the tests which were less affected by the LMWH (APTT, TT([6 IU ml)(-1)(])), only small increases (< 4 seconds) were observed even after the highest subcutaneous LMWH dose. The correlation between plasma heparin activity and the relative alteration compared to the initial value (ratio), of the different coagulation tests was only moderate and considerably lower for RTG-r (r(s)= 0.526) than for the TT (r(s)= 0.711([6 IU ml(-1)]), r(s)= 0.780([3 IU ml(-1)])) and APTT (r(s)= 0.667([reagent 1]), r(s)= 0.727([reagent 2])). The low degree of prolongation, which was found particularly for the group tests APTT and TT([6 IU ml)(-1)]), reflects the low anti-thrombin activity of LMWH. The results indicate that measurement of anti-FXa activity with chromogenic substrates is the method of choice to control LMWH therapy in dogs, as is the case in humans. Copyright2000 Harcourt Publishers Ltd Copyright 2000 Harcourt Publishers Ltd. 相似文献
19.
《The Journal of small animal practice》1978,19(1-12):417-422
The activated coagulation time (ACT) of whole blood was determined at 37C and at room temperature for 42 normal dogs and eight dogs with naturally–occurring or experimentally–induced coagulation defects.
Normal ACT values ranged from 64 to 95 seconds at 37C, and 83 to 129 seconds at room temperature. In abnormal dogs, ACT was increased on 14 of 17 occasions that a prolonged activated partial thromboplastin time (APTT) was recorded: the ACT failed to detect an abnormality on three occasions the APTT was slightly increased. ACT determination at 37C correlated better with APTT than did ACT testing at room temperature.
The ACT test is simple, inexpensive and convenient. It is a useful screening test for intrinsic coagulation defects in the dog. It is suggested that the test be performed at 37C: at this temperature an ACT of 95 seconds or more in a dog warrants further investigation. 相似文献
Normal ACT values ranged from 64 to 95 seconds at 37C, and 83 to 129 seconds at room temperature. In abnormal dogs, ACT was increased on 14 of 17 occasions that a prolonged activated partial thromboplastin time (APTT) was recorded: the ACT failed to detect an abnormality on three occasions the APTT was slightly increased. ACT determination at 37C correlated better with APTT than did ACT testing at room temperature.
The ACT test is simple, inexpensive and convenient. It is a useful screening test for intrinsic coagulation defects in the dog. It is suggested that the test be performed at 37C: at this temperature an ACT of 95 seconds or more in a dog warrants further investigation. 相似文献
20.
B W Parry 《Veterinary Clinics of North America: Small Animal Practice》1989,19(4):729-742
Assessment of animals with a suspected hemorrhagic diathesis of unknown cause(s) should be methodical. Most acquired coagulopathies result from thrombocytopenia. A platelet estimate (from a blood smear) and/or a platelet count on a fresh blood sample therefore are useful first steps in case evaluation. If thrombocytopenia is present, the most likely causes are immune-mediated destruction of platelets, DIC, or megakaryocytic hypoplasia. These diagnoses can be pursued by further test, including antiplatelet antibody assays (for example, the platelet factor 3 tests or an ELISA test), measurement of FDP, and bone marrow biopsy, respectively. If the platelet count is normal, a buccal mucosa bleeding time test is a useful second step. If this is prolonged, most likely causes are vWD or a thrombocytopathy (functional platelet defect). von Willebrand's disease can be diagnosed by measurement of vWf concentration or activity. A normal bleeding time does not exclude a diagnosis of vWD, but suggests that the functional activity of vWf is not compromised markedly. If the bleeding time is normal, APTT and PT should be measured. A prolonged APTT with normal PT, in the clinical setting, implies a deficiency of factor XI, IX, or VIII. A prolonged PT with normal APTT indicates factor VII deficiency. Prolongation of both APTT and PT usually is caused by a deficiency of several factors and is seen most often in cases with vitamin K deficiency or antagonism. Obviously, if a particular cause is suspected from the case history or for other reasons, appropriate tests should be evaluated at the beginning. If these do not confirm the provisional diagnosis, the just-described protocol might be a useful one to follow. 相似文献