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1. Brief Clinical Communication Journal of Veterinary Emergency and Critical Care 24(4) 2014, pp 455–460
doi: 10.1111/vec.12200
Assessment of a portable prothrombin time
analyzer (CoaguChek-XS) in dogs
Efrat Kelmer, DVM, MS, DACVECC; Gilad Segev, DVM, DECVIM; Carolina Codner, DVM;
Yaron Bruchim, DVM, DACVECC; Sigal Klainbart, DVM, DACVECC and
Itamar Aroch, DVM, DECVIM
Abstract
Objectives – To assess the performance of a portable prothrombin time (PT) analyzer (CoaguChek-XS) in dogs.
Animals – Ninety-seven dogs composed of 20 healthy dogs, 45 ill dogs, and 32 ill dogs with altered coagulation.
Procedures – Samples were concurrently obtained and PT was measured using the CoaguChek-XS and an
automated coagulation analyzer. Agreement between methods was assessed using Spearman’s correlation and
Bland–Altman analysis.
Results – The reference interval for PT using the CoaguChek-XS was 9.6–11.5 s. The CoaguChek-XS was easy to
use, required a small volume of whole blood, and gave results within 1 min. The mean difference in PT between
the 2 methods was 2.58 s (SD 3.10), and 94% of the samples fell within limits of agreement. The correlation was
moderate, but significant (r = 0.35, P < 0.001). Sensitivity and specificity of the CoaguCheck-XS PT compared
to analyzer PT were 92% and 56%, respectively, and increased to 95% and 77% on intent to treat basis. The
coefficient of variance was 0.72%.
The CoaguChek-XS identified all 8 dogs with anticoagulant rodenticide intoxication, although a discrepancy
was noted from the analyzer results. In anemic dogs (PCVࣘ25%), the CoaguChek-XS did not display accurate
results.
Conclusions – The CoaguChek-XS is a simple, user-friendly, highly precise PT analyzer. Results had moderate
correlation and good agreement with a standard method. It can be used reliably for screening dogs when the
PT is normal. However, when the CoaguChek-XS PT is prolonged or when the PCV is ࣘ25%, results should be
confirmed using a standard method.
(J Vet Emerg Crit Care 2014; 24(4): 455–460) doi: 10.1111/vec.12200
Keywords: coagulation testing, coagulopathy, point-of-care testing
Introduction
The use of portable, point-of-care (POC) coagulation
analyzers for prothrombin time (PT) and international
normalized ratio (INR) testing has recently gained
popularity in human medicine. These analyzers allow
convenient, simple, at-home monitoring of warfarin
therapy, and improved management of anticoagulation.
Portable analyzers have several advantages over tradi-
tional methods, including ease of use, low maintenance,
From the Department of Small Animal Emergency and Critical Care, the
Hebrew University Veterinary Teaching Hospital, Koret School of Veterinary
Medicine, Rehovot, Israel.
The CoaguChek-XS test strips, and some of the reagents used for ACA-
PT, were provided by DYN Diagnostics LTD, Caesarea, Israel. The authors
declare no other conflict of interests.
Address correspondence and reprint requests to
Dr. Kelmer, Hebrew University Veterinary Teaching Hospital, Koret
School of Veterinary Medicine, PO Box 12, Rehovot 76100, Israel. Email:
kelmere1@gmail.com
Submitted September 21, 2012; Accepted May 25, 2014.
Abbreviations
ACA automated coagulation analyzer
ACA-PT prothrombin time measured by the ACA
CCX-PT Prothrombin time measured by the
CoaguChek-XS
INR international normalized ratio
ISI international sensitivity index
POC point-of-care
PT prothrombin time
RI reference interval
immediate results, and requirement for a small volume
of whole blood for testing.1
Automated coagulation analyzers (ACA) generally
measure PT by adding a mixture of calcium and throm-
boplastin to citrated plasma, and recording the time un-
til a clot has formed.2
Results differ among laboratories
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Veterinary Emergency and Critical Care Society 2014 455

2. E. Kelmer et al.
Figure 1: The CoaguChek-XS portable PT analyzer. Once the
strip is inserted and internally calibrated, 180 s are allowed to
place a blood drop on the strip (A). The CoaguChek-XS PT ana-
lyzer is shown, displaying a PT of 10.6 s (B).
because of differences in the sensitivity of commercially
available thromboplastins in the particular analyzer and
the clot detection method.2
The international sensitiv-
ity index (ISI) measures the thromboplastin respon-
siveness, compared with a World Health Organization
reference preparation. A lower ISI reflects a more sensi-
tive reagent.3
The PT ratio is calculated by dividing the
patient’s measured PT by the mean PT obtained from
at least 20 normal individuals using the same reagent
and equipment. The INR was instituted by the World
Health Organization in an attempt to standardize PT re-
sults obtained by different laboratories, and is calculated
as the (PT ratio)ISI
.3
The INR is routinely used in human
medicine but not in veterinary medicine.
Several POC coagulation analyzers are commercially
available for use in human medicine, and data regard-
ing their accuracy and precision have been reported.4–10
Such devices are also penetrating the veterinary market,
and 2 POC coagulation analyzers have been evaluated
in dogs.11,12
The CoaguChek-XSa
is a second-generation,
portable, battery-powered, laser photometer, weighing
175 g (batteries included) and fits in a human hand
(Figure 1). It uses a thromboplastin and iron particle-
containing test cartridge, which is inserted into a slot in
the analyzer. A drop of fresh whole blood is placed on
the test area, and is then drawn through capillary force
into a rabbit brain thromboplastin-containing chamber,
where it mixes with the reagent, initiating coagulation. A
pulsating magnetic field is activated, and induces move-
ment of the paramagnetic iron-oxide particles contained
within the cartridge. When the blood sample clots, iron-
oxide particle movement ceases, leading to decreased
laser light reflectance detected by a photosensor. This
time result is recorded as the PT, and is displayed in
seconds and INR units. The analyzer is internally cali-
brated to a mean PT of 12.6 s. The reported CoaguChek-
XS PT (CCX-PT) RI in people is 12–15 s, and thus, the
INR equals PT/12.6. Thromboplastin-specific calibra-
tion information, read by the analyzer, for each lot of
strips, is coded on a lot-specific chip. The thromboplas-
tin reagent’s ISI reported by the manufacturer is 1.01.13
Chronic first generation anti-coagulant (ie, warfarin)
therapy in dogs is uncommon; however, it has been used
for long-term management of dogs who have received
tricuspid and mitral valve replacements.14,15
Anticoagu-
lant rodenticide intoxication is frequently diagnosed in
dogs, and was the 3rd and 2nd most common intoxica-
tion in dogs reported by the US Animal Poison Control,
and the UK Veterinary Poisons Information Service web-
site in year 2010, respectively.16,17
In-house coagulation
tests are often unavailable in private veterinary prac-
tices, and testing by reference laboratories may delay
the reporting of results and is limited by the laboratory
working hours.
The CoaguChek-XS analyzer has been evaluated in
dogs in a recent report.18
The aim of the current
study was to assess the accuracy and precision of the
CoaguChek-XS compared to a routine automated coag-
ulometric method of PT measurement in dogs.
Materials and Methods
Selection of dogs
The study was approved by the Institutional Animal
Care and Use Committee. Control dogs were recruited
from staff-owned dogs or those presented for routine cas-
tration. Staff-owned dogs were determined to be healthy
based on a thorough history and physical examination,
and a normal CBC was recorded for all dogs undergo-
ing castration. The remaining dogs that supplied sam-
ples for the study were clinical patients presented to the
hospital’s emergency service for evaluation of various
medical conditions. Selection of clinical cases was con-
secutive and depended on presence in the clinic of 1 of
the 2 authors qualified to perform the CoaguChek-XS
measurements at the time when blood samples were ob-
tained. Patients were divided into 2 groups based on the
likelihood of the presence of a coagulopathy.
Collection of blood
Whole blood samples were collected by direct venipunc-
ture or from an IV catheter immediately upon inser-
tion. Following the blood draw, 1.8 mL of blood was
placed in a 3.2% 2 mL trisodium-citrate tube,b
while the
remaining blood was immediately used for the CCX-
PT measurement, performed according to the manu-
facturer’s instructions. Samples for PT testing by the
automated coagulation analyzer were centrifuged
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3. Assessment of the CoaguChek-XS PT analyzer
within 15 min from collection (1,500 ×g for 5 min, at
room temperature) and harvested plasma was either an-
alyzed immediately (n = 65), or immediately stored at –
80°C, pending analysis, and performed within 3 months
of collection (n = 32). Collection of all blood samples
and measurement of the CCX-PT were performed by
1 of 2 authors. For the CCX-PT precision assessment,
fresh whole blood samples from 10 healthy dogs were
collected by 3 separate venipunctures within 10 min us-
ing a 25 Ga needle and a 1 mL syringe, and analyzed
immediately.
Routine PT testing
Routine PT was measured at the institutional diagnostic
laboratory using an ACAc
calibrated for canine plasma
(ACA-PT). The laboratory PT reference interval (RI) for
dogs is 6.0–8.5 s. The CCX-PT RI for dogs was based
on 20 healthy dogs whose PT, tested by the ACA, was
within the laboratory’s RI. As the CoaguChek-XS is not
designed to measure shorter than normal PT, results
lower than 9.6 s are displayed as 9.6 s.
Statistical analysis
The distribution pattern of continuous variables was
assessed by the Shapiro–Wilk test. The correlation be-
tween paired PT results, generated by the CoaguChek-
XS and the ACA, was assessed using a Spearman rank
correlation test. Bland–Altman analysis was used to fur-
ther assess the agreement between the 2 PT testing
methods.19
The bias (mean bias, average of the differ-
ences between the 2 measurements) represents the sys-
tematic error between the 2 testing methods, and the
SD of the bias represents the random error, or variabil-
ity, between different testing methods. In the Bland–
Altman plot, points in complete agreement would fall
on the zero axis. For a strong indication of agreement,
roughly 95% of the data points should fall within the 95%
limits of agreement (plus and minus 2 standard devia-
tions from the mean) and should appear random in their
distribution.
To measure CoaguChek-XS precision, the mean and
the SD was calculated of each set of 3 measurements ob-
tained from the healthy dogs. For each of these dogs,
the SD was divided by the mean to calculate the co-
efficient of variation of each sample. Finally, all the
above-calculated coefficients of variation were averaged
to calculate the mean coefficient of variation, which was
used as a measure of precision. Statistical analyses were
performed using a commercial software package.d
For
all tests, a P value 0.05 was considered statistically
significant.
Results
Signalment and diagnoses
The study included 97 dogs of various breeds. Thirty-
nine were male (19 neutered) and 58 were female (27
neutered), with a median age and body weight of 7
years (range 0.25–16) and 24.5 kg (range 4–70), respec-
tively. There were 20 healthy dogs, 45 dogs diagnosed
with various diseases deemed unlikely to affect coag-
ulation, and 32 dogs diagnosed with conditions poten-
tially affecting coagulation. The latter group included
dogs with anticoagulant rodenticide intoxication (8 dogs,
8%), gastric dilatation and volvulus (5 dogs, 5%), sep-
tic peritonitis (4 dogs, 4%), hemoperitoneum secondary
to splenic hemangiosarcoma (4 dogs, 4%), immune-
mediated thrombocytopenia (3 dogs, 3%) and immune-
mediated hemolytic anemia, pyometra with pancreati-
tis, parvovirus enteritis, spinal-cord bleeding, Vipera
palaestinae snakebite, suspected brown recluse enveno-
mation, icterus and disseminated intravascular coagula-
tion (of undetermined cause), and hyperadrenocorticism
(1 each, 1%).
The ACA-PT was below RI in 17 dogs (17.5%), within
RI in 41 dogs (42.3%) and above RI in 39 dogs (40.2%).
Of the dogs with ACA-PT above RI, in 16 (16.5%) the PT
was at least 1.5-fold the upper RI.
CoaguChek-XS performance and PT results
The CoaguChek-XS analyzer required less than 0.05 mL
of whole blood and provided results within 1 min from
application of the blood sample on the strip. The CCX-PT
RI was 9.6–11.5 s. In all dogs in which the ACA PT was
below RI (n = 17), the CCX-PT was within RI. Because the
CoaguChek-XS does not report results below its lower
limit of detection, for the statistical analyses, these results
were considered to have agreement between the 2 PT
measurement methods.
A total of 14/97 (14.5%) samples were excluded from
statistical analyses. In 7 of these, the CoaguChek-XS did
not display the PT in seconds, but displayed only the
calculated INR. All 7 of these dogs were severely anemic
(PCV ࣘ 25%), and 2 of them had markedly prolonged
ACA-PT due to anticoagulant rodenticide intoxication.
Based on the information provided by the manufacturer,
the CoaguChek-XS is inaccurate in PCV ranges of 25%
or 55%. In 4 additional dogs with anticoagulant roden-
ticide intoxication, both the ACA and the CoaguChek-XS
displayed error messages, indicating PT prolonged be-
yond the test range. In 1 additional dog with splenic
hemangiosarcoma, the CoaguChek-XS reported an “er-
ror 6” message (measurement error), while the ACA re-
ported a mildly prolonged PT (10.4 s). This dog was not
anemic. In the remaining 2 dogs, there was a discrepancy
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4. E. Kelmer et al.
Figure 2: Bland–Altman (B–A) plot for assessment of the agree-
ment between the CoaguChek-XS and the automated coagulo-
metric analyzer PTs in 83 dogs. Ninety-four percent of the results
fell within the limits of agreement. In a B–A plot, points in full
agreement fall on the zero axis. For a strong indication of agree-
ment, roughly 95% of the results should fall within the limits
of agreement (ie, the mean difference ± 2 SD) and should be
distributed randomly.19
between methods, such that the ACA-PT was within RI,
whereas the CCX-PT was markedly prolonged.
The mean difference between the CCX-PT and ACA-
PT was 2.58 s (SD 3.10). The Bland–Altman plot showed
that 78/83 of the samples (94%) fell within limits of agree-
ment (Figure 2). There was a significant, albeit moderate,
overall linear correlation between the 2 PT measurement
methods (r = 0.35, P 0.001). The sensitivity and speci-
ficity for the CCX-PT, using the ACA-PT as the gold
standard, were 92% and 56%, respectively. The mean co-
efficient of variation was 0.72%
For analysis of the results on an intent to treat ba-
sis, we assumed that therapeutic interventions would be
considered if the PT is prolonged to at least 1.5 times the
upper end of the RI. Based on this PT cutoff, in 11/97
dogs (11%), therapeutic intervention, when based on the
CCX-PT, would differ from a decision made based on
ACA-PT. These 11 cases included the 2 dogs (2%) that
were considered outliers as their ACA-PT was within RI,
whereas the CCX-PT was markedly prolonged, 2 dogs
with markedly prolonged CCX-PT that had moderately
prolonged ACA-PT, and 7 dogs (7%) with markedly pro-
longed ACA-PT, but with only moderately prolonged
CCX-PT. Sensitivity and specificity of the CoaguChek-
XS in correctly detecting normal or abnormal PT when
compared to the ACA were 93% and 77%, respectively.
The CCX-PT results of the 8 dogs with anti-coagulant
rodenticide intoxication were all markedly prolonged. In
4 of these, both the CCX-PT and the ACA-PT were not
displayed as numeric values, but rather results above
test range were displayed. In 3 of these latter 4 dogs,
the CoaguChek-XS displayed an error 6 message, in-
dicating a measurement error, and in 1 dog, an error
7 message, referring to inability of the sample to form
a clot. In the 4 remaining dogs, the CoaguChek-XS re-
ported an abnormally prolonged PT; however, there was
a significant discrepancy between these measures and
the ACA PT. In 2 of these dogs, the PCV was 25%.
Discussion
This study assessed the precision of the portable, bed-
side, CoaguChek-XS PT analyzer in dogs. In addition, the
accuracy, as measured by statistical agreement and the
clinical implications of its results compared to standard
ACA PT measurement, was evaluated. The CoaguChek-
XS can be used reliably for PT screening in dogs. If the
CCX-PT is within RI, its expected agreement with a ref-
erence ACA method is 93%, and in 98% of the cases
such result will not lead to an inappropriate therapeutic
decision. However, if a prolonged CoaguCheck-XS PT
result is obtained, the agreement with the ACA method
substantially decreases, and in 9% of the cases, results
might lead to incorrect therapeutic decisions. Therefore,
when a prolonged PT is obtained using the CoaguChek-
XS in dogs, citrated blood samples should be submitted
to a reference laboratory for confirmation of the PT using
standard methods.
The Bland–Altman analysis showed that CCX-PT had
very good agreement with the reference ACA method,
although the Spearman rank correlation coefficient was
suggestive of only a moderate agreement. Nonethe-
less, the correlation between methods provides only one
aspect of the evaluation. A tested method may have
high correlation with the reference method, but it could
also concurrently display a consistent, large error com-
pared to the reference method.19
Although the corre-
lation between CoaguCheck-XS and ACA-PT measure-
ments was only moderate, most PTs were within or
slightly above or below the corresponding values and
in most dogs these differences were deemed clinically
insignificant.
The CoaguChek-XS is designed for home PT monitor-
ing by human patients. As such, it is a portable, easy to
operate, low maintenance analyzer, requiring minimum
quality control, and a very small blood sample volume.
These advantages were also apparent in our study. This
portable PT analyzer may provide a viable, affordable
screening method for coagulopathies characterized by a
prolonged PT (eg, anti-coagulant rodenticide intoxica-
tion) unless the initial PT is substantially prolonged or
the dog is anemic.
A recent study that evaluated the accuracy of the
CoaguChek-XS in 54 dogs (40 healthy dogs and 13
with coagulopathies) showed that the analyzer had ex-
cellent agreement with a reference PT measurement
method.18
As in the current study, the accuracy of the
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5. Assessment of the CoaguChek-XS PT analyzer
CoaguChek-XS decreased in samples in which the refer-
ence method PTs were prolonged, and in hemolyzed or
anemic samples.18
In addition, and similar to the results
reported here, in 4 of 53 samples (7.5%) the CoaguChek-
XS was unable to display the PT results, and displayed
only the calculated INR result. In that report and the
present one, this occurred in samples in which the stan-
dard ACA-PTs were abnormally prolonged or when an-
imals were anemic. According to the manufacturer, the
analyzer reports only an INR result when the sample
is interpreted by the device as a quality control sam-
ple (indicated by a lowercase “c” in the display).18
In
addition, based on the manufacturer’s package insert,
the CoaguChek-XS provides accurate results only when
sample hematocrit is between 25% and 55%. As all the re-
sults that were displayed only as INR in our study were
from dogs with PCV ࣘ25%, we suspect that the analyzer
interpreted these as quality control samples, and only
displayed the results as INR.
To the authors’ knowledge, 2 other POC coagulation
analyzers have been assessed and validated in veteri-
nary medicine, including the SCA-2000 Veterinary Coag-
ulation Analyzere,12
and the Abaxis VSPro Coagulation
Analyzer.f,11
The i-stat ACTg
methodology to measure
activated clotting time has been validated in people,7,10,20
but not in animals. The CoaguChek-XS had a higher sen-
sitivity, but lower specificity compared to the SCA-2000,
and a lower correlation to reference method compared
to the Abaxis (r = 0.35 versus 0.578).11,12
Routine oral anti-coagulant treatment is uncommonly
practiced in dogs, although in certain cases (eg, treat-
ment for aortic thromboembolism21
and following heart
valve replacement surgery14,15
) long-term warfarin ther-
apy may be indicated in dogs. In such instances, home
PT monitoring using the device may be considered. The
CoaguChek-XS can be reliably used for exclusion of anti-
coagulant rodenticide intoxication, because PT is invari-
ably prolonged in such intoxications.22
The use of the
CoaguChek-XS is limited to samples with hematocrits
between 25% and 55%, which may limit its diagnostic
utility in patients who are anemic because of hemorrhage
of unknown origin.
This study has 2 major limitations. First, the blood
collection site and technique might have affected results,
and might have introduced variance. Several different
large veins were used in this study and ideally, collec-
tion of all blood samples should have been made us-
ing the same vessel, preferably the jugular vein. In this
clinical study, ethical limitations for avoiding unneces-
sary venipunctures in client-owned dogs dictated this
decision. Second, the number of dogs in this study was
small, especially the number of dogs with significantly
prolonged PT values (n = 16), thereby limiting the power
of the statistical analyses.
The CoaguChek-XS was simple to operate, required a
very small blood sample volume, provided very quick
results, and had excellent precision. In dogs with PTs
within the RI, the CoaguChek-XS had a small mean dif-
ference, excellent limits of agreement, and significant,
albeit moderate correlation with a standard reference
method. The CoaguChek-XS can be used for PT screen-
ing of patients with hypocoagulable states; however, in
dogs with abnormally prolonged PT and in anemic dogs,
the CoaguChek-XS had difficulty displaying a measur-
able PT. In such cases, reference PT measurement meth-
ods should be employed.
Acknowledgments
The authors thank Ms. Maria Griber and Dr. Tamara
Shapiro of the HUVTH Diagnostic Laboratory for their
technical assistance.
Footnotes
a
CoaguChek-XS, Roche, Mannheim, Germany.
b
Vacuette, Grainer Bio-One, VWR International, Milano,
Italy.
c
ACL 200, Instrumentation Laboratory, Milano, Italy; reagent HemosIL PT-
fibrinogen recombinant 0020005000, ISI – 1.0, Instrumentation Laboratory,
Milano, Italy.
d
SPSS 17.0, SPSS Inc., Chicago, IL.
e
SCA-2000, Synbiotics, San Diego, CA.
f
Abaxis, Arrow International, Raleigh, NC.
g
i-stat, Abbott Laboratories, Abbott Park, IL.
References
1. Nutescu EA. Point of care monitors for oral anticoagulant therapy.
Semin Thromb Haemost 2004; 30(6):697–702.
2. Hirsh J. Oral anticoagulant drugs. N Engl J Med 1991; 324:1865–1875
3. Hirsh J, Poller L. The international normalized ratio. A guide to
understanding and correcting its problems. Arch Intern Med 1994;
154(3):282–288.
4. Chavez JJ, Weatherall JS, Strevels SM, et al. Evaluation of a point-of-
care coagulation analyzer on patients undergoing cardiopulmonary
bypass surgery. J Clin Anesth 2004; 16(1):7–10.
5. Dempfle CE, Borggrefe M. Point of care coagulation tests in
critically ill patients. Semin Thromb Hemost 2008; 34(5):445
–450.
6. Kapiotis S, Quehenberger P, Speiser W. Evaluation of the new
method Coaguchek for the determination of prothrombin time from
capillary blood: comparison with Thrombotest on KC-1. Thromb Res
1995; 77(6):563–567.
7. Lewandrowski EL, Van Cott EM, Gregory K, et al. Clinical eval-
uation of the i-STAT kaolin activated clotting time (ACT) test in
different clinical settings in a large academic urban medical center:
comparison with the Medtronic ACT Plus. Am J Clin Pathol 2011;
135(5):741–748.
8. Moon JR, Jeong SI, Huh J, et al. Accuracy of CoaguChek XS for point-
of-care antithrombotic monitoring in children with heart disease.
Ann Clin Lab Sci 2010; 40(3):247–251.
9. Plesch W, Wolf T, Breitenbeck N, et al. Results of the perfor-
mance verification of the CoaguChek XS system. Thromb Res 2008;
123(2):381–389.
10. Schussler JM, Lander SR, Wissinger LA, et al. Validation of the i-
STAT handheld activated clotting time for use with bivalirudin. Am
J Cardiol 2004; 93(10):1318–1319.
C
Veterinary Emergency and Critical Care Society 2014, doi: 10.1111/vec.12200 459

6. E. Kelmer et al.
11. Dixon-Jimenez, AC, Brainard, BM, Cathcart, CJ, Koenig, A. Eval-
uation of a point-of-care coagulation analyzer (Abaxis VSPro) for
identification of coagulopathies in dogs. J Vet Emerg Crit Care 2013;
23(4):402–407.
12. Tseng LW, Hughes D, Giger U. Evaluation of a point-of-care coag-
ulation analyzer for measurement of prothrombin time, activated
partial thromboplastin time, and activated clotting time in dogs.
Am J Vet Res 2001; 62(9):1455–1460.
13. Leichsenring I, Plesch W, Unkrig V, et al. Multicentre ISI assignment
and calibration of the INR measuring range of a new point-of-care
system designed for home monitoring of oral anticoagulation ther-
apy. Thromb Haemost 2007; 97(5):856–861.
14. Arai S, Griffiths LG, Mama K, et al. Bioprosthesis valve replacement
in dogs with congenital tricuspid valve dysplasia: technique and
outcome. J Vet Cardiol 2011; 13(2):91–99.
15. Orton EC, Hackett TB, Mama K, et al. Technique and outcome
of mitral valve replacement in dogs. J Am Vet Med Assoc 2005;
226(9):1508–1511.
16. ASPCA. Available at: http://www.aspca.org/pet-care/poison-
control/top-10-pet-poisons-of-the-year.aspx. Accessed on June 15,
2012.
17. UK Veterinary poisons information service website. Available at:
http://www.vpisuk.co.uk/portal/CommonPoisons/tabid/119/
Default.aspx. Accessed on June 15, 2012.
18. Newbould A, Norman E. Comparison of point-of-care
analysis using Coaguchek XS and standard laboratory-
measured prothrombin time in dogs. N Z Vet J 2013; 61(1):
18–24.
19. Bland MJ, Altman DG. Statistical methods for assessing agree-
ment between two methods of clinical measurement. Lancet 1986;
1(8476):306–310.
20. Guzzetta NA, Monitz HG, Fernandez JD, et al. Corre-
lations between activated clotting time values and hep-
arin concentration measurements in young infants under-
going cardiopulmonary bypass. Anesth Analg 2010; 111(1):
173–179.
21. Winter RL, Sedacca CD, Adams A, et al. Aortic thrombosis in dogs:
presentation, therapy, and outcome in 26 cases. J Vet Cardiol 2012;
14(2):333–342.
22. Brooks MB, DeLaforcade A. Aquired coagulopathies. In: Weiss DJ,
Wardrop KJ. eds. Schalm’s Veterinary Hematology. Hoboken, NJ :
Wiley-Blackwell, 2010.
460 C
Veterinary Emergency and Critical Care Society 2014, doi: 10.1111/vec.12200