Objective—To detect subclinical disseminated
intravascular coagulation (DIC) in horses with colitis
and to determine any association between the diagnosis
of subclinical DIC and outcome or occurrence of
complications in horses with colitis.
Animals—37 horses admitted to a veterinary teaching
hospital for treatment of acute colitis.
Procedure—Coagulation profiles were obtained on
each horse 0, 24, and 48 hours after admission. Six
tests were performed: platelet count, plasma fibrinogen
concentration, prothrombin time, activated partial
thromboplastin time, antithrombin activity, and serum
fibrin degradation products concentration.
Results—A clinicopathologic diagnosis of subclinical
DIC was made if 3 of the 6 tests had abnormal results
at any 1 sample period. No horse had clinical signs of
DIC at the time of sampling. Twelve of 37 (32%) horses
met the criteria for diagnosis of subclinical DIC
within a 1-year period. Outcome was defined as survival
or nonsurvival. Five of 12 horses with subclinical
DIC and 2 of 25 horses without subclinical DIC did not
survive. Crude odds ratio analysis revealed a horse
with acute colitis was 8 times as likely to die or be
euthanatized if a diagnosis of subclinical DIC was
Conclusions and Clinical Relevance—Clinicopathologic
evidence of DIC is common and is significantly
associated with a poor outcome in horses with
acute colitis. Treatment of subclinical DIC may influence
outcome in horses with acute colitis. (J Am Vet
Med Assoc 2002;220:1034–1038)
Objective—To review management of pregnant mares with body wall defects and assess the effect of various management strategies on the outcome of mares and their foals.
Design—Retrospective case series.
Procedures—Medical records of eligible mares were reviewed. Signalment, history, admitting complaint, clinical findings, parity, type of body wall defect, concurrent diagnoses, postpartum complications, outcome of fetus, outcome of mare, and type of clinical case management were recorded.
Results—8 mares received conservative management and 5 mares received interventional management. Survival of mares to discharge was good, and no difference in mare survival was identified on the basis of type of management, type of body wall defect, or presence of hydrops. Foal survival was significantly better in the conservative management group, compared with those managed by interventional management, and was also better without hydrops.
Conclusions and Clinical Relevance—Foal survival can be improved in mares with body wall defects that occur during parturition without compromising mare survival by use of conservative management strategies that avoid induction of parturition or elective caesarian section and allow for natural parturition. Potentially, improved fetal readiness for birth may play a role.
OBJECTIVE To evaluate the degree of activation of the contact pathway in citrated equine whole blood over holding times ≤ 30 minutes and assess effects of contact activation on recalcification-initiated thromboelastometry.
ANIMALS 11 healthy adult mixed-breed horses.
PROCEDURES Blood was collected by atraumatic jugular venipuncture into prewarmed evacuated siliconized glass tubes containing citrate anticoagulant and held at 37°C for ≤ 30 minutes. Thromboelastometry was performed with an in vitro viscoelasticity (thromboelastometry) monitoring system. Factor XII and factor XI procoagulant activities were determined in contemporaneously collected platelet-poor plasma samples by assessing changes in turbidity for 1 hour at approximately 25°C, with clotting times calculated by fitting a line to the steepest segment of the absorbance curve and determining its intersection with baseline. Effect of holding time on thromboelastometry parameters and plasma enzyme activity was evaluated by repeated-measures ANOVA on ranks. Association of procoagulant activities with coagulation time was determined by Spearman rank-order correlation analysis.
RESULTS Thromboelastometry parameters (coagulation time, clot formation time, α angle, and maximum clot firmness) reflected significant increases in coagulability during the holding period. Factor XII and factor XI procoagulant activities were significantly increased at 30 minutes, compared with 2 or 10 minutes (indicating contact activation of samples), and had significant negative correlation with coagulation time.
CONCLUSIONS AND CLINICAL RELEVANCE Ex vivo activation of the contact system in equine whole blood was evident, suggesting that recalcification of blood in the absence of a trigger is not an acceptable method of assessing the hemostatic system in horses.
Case Description—6 female alpacas, ranging in age from < 1 day to > 2 years, were examined because of primary owner complaints related to urogenital malformation.
Clinical Findings—In all instances, the vulva was totally to subtotally imperforate. One neonate had failure of passive transfer of immunity and mild azotemia at the time of initial examination. No additional urogenital malformations were detected in any of the alpacas.
Treatment and Outcome—Vulvoplasty performed via local anesthesia was successful in all alpacas. The neonate with failure of passive transfer received a plasma transfusion. Postsurgical wound management was limited to topically applied medications.
Clinical Relevance—Congenital vulvar deformity in alpacas may result in interference with urine outflow. Neonates with a completely imperforate vulva may be brought to veterinarians for examination on an emergency basis. Less severely affected alpacas may be examined later in life with owner complaints ranging from stranguria or dysuria to urogenital malformation. No other primary abnormalities of the urogenital tract in alpacas have been reported, to the authors' knowledge. Vulvoplasty, performed with local anesthesia, resolves obstructed urine flow. Because it is possible that this condition is heritable, affected alpacas, and possibly their sires and dams, should not be used for breeding.
Objective—To compare cardiac output measured in
the pulmonary artery and a carotid artery by use of
thermal and electrical impedance dilution.
Animals—7 fit, clinically normal Standardbreds
between 2 and 5 years of age.
Procedure—Transient changes in electrical impedance
and temperature of blood were induced by bolus
injections of ice-cold saline hypertonic (6% and 9%
NaCl) solutions. Cardiac output was calculated by
applying Stewart-Hamilton principles to the indicator
dilution transients. Measurements were made during
sequential exercise episodes on a level treadmill over
approximately an 8-fold range of cardiac output values.
Results—We detected agreement between cardiac
output determined by use of electrical impedance
dilution at the pulmonary artery and carotid artery.
Cardiac output from thermal dilution measured at the
carotid artery exceeded that measured at the pulmonary
artery. Cardiac output from the thermal dilution
technique exceeded cardiac output from the electrical
impedance dilution technique at both locations.
Conclusions and Clinical Relevance—The electrical
impedance indicator is conserved on first transit;
therefore cardiac output measured by electrical
impedance dilution at the carotid artery is reliable over
a large range of values. Thermal dilution provides a
larger estimate of cardiac output, compared with the
electrical impedance dilution technique, probably
because of a loss of indicator. The transpulmonary
electrical impedance dilution technique may have
potential for clinical application, particularly in animals
in which catheterization of the pulmonary artery is not
appropriate or blood loss must be minimized. (Am J
Vet Res 2005;66:878–884)
Objective—To qualitatively describe lung CT images obtained from sedated healthy equine neonates (≤ 14 days of age), use quantitative analysis of CT images to characterize attenuation and distribution of gas and tissue volumes within the lungs, and identify differences between lung characteristics of foals ≤ 7 days of age and foals > 7 days of age.
Animals—10 Standardbred foals between 2.5 and 13 days of age.
Procedures—Foals were sedated with butorphanol, midazolam, and propofol and positioned in sternal recumbency for thoracic CT. Image analysis software was used to exclude lung from nonlung structures. Lung attenuation was measured in Hounsfield units (HU) for analysis of whole lung and regional changes in attenuation and lung gas and tissue components. Degree of lung attenuation was classified as follows: hyperinflated or emphysema, −1,000 to −901 HU; well aerated, −900 to −501 HU; poorly aerated, −500 to −101 HU; and nonaerated, > −100 HU.
Results—Qualitative evidence of an increase in lung attenuation and patchy alveolar patterns in the ventral lung region were more pronounced in foals ≤ 7 days of age than in older foals. Quantitative analysis revealed that mean ± SD lung attenuation was greater in foals ≤ 7 days of age (−442 ± 28 HU) than in foals > 7 days of age (−521 ± 24 HU). Lung aeration and gas volumes were lower than in other regions ventrally and in the mid lung region caudal to the heart.
Conclusions and Clinical Relevance—Identified radiographic patterns and changes in attenuation were most consistent with atelectasis and appeared more severe in foals ≤ 7 days of age than in older neonatal foals. Recognition of these changes may have implications for accurate CT interpretation in sedated neonatal foals with pulmonary disease.
OBJECTIVE To compare CT and radiographic images of the lungs in sedated healthy foals positioned in sternal recumbency and to investigate whether a relationship exists between CT-derived measurements of lung attenuation and Paco2 and Pao2.
ANIMALS 6 healthy Standardbred foals < 14 days of age.
PROCEDURES Thoracic CT images were acquired followed by radiographic views with each foal sedated and positioned in sternal recumbency. For each foal, both CT and radiographic images were evaluated for severity and extent of changes by lung regions on the basis of a subjective scoring system by 3 investigators. Quantitative analysis of CT images was also performed. Assessments of Pao2 and Paco2 were performed before sedation, following sedation prior to CT, and after CT prior to radiography.
RESULTS Interobserver agreement for CT and radiographic image scoring was strong (0.73) and fair (0.65), respectively; intraobserver agreement was near perfect for CT (0.97) and radiographic (0.94) image scoring. Increased CT attenuation and radiographic changes were identified for all foals and were preferentially distributed in the caudoventral portion of the lungs. Radiographic scores were significantly lower than CT image scores. A positive correlation (r = 0.872) between lung attenuation and CT image score was identified. A significant increase in Paco2 was not considered clinically relevant. Significant changes in Pao2 were not observed.
CONCLUSIONS AND CLINICAL RELEVANCE Results suggested that interpretation of CT images may be less subjective, compared with interpretation of radiographic images. These findings may aid in the evaluation of CT and radiographic images of neonatal foals with respiratory tract disease.
To evaluate the repeatability and accuracy of fingertip pulse oximeters (FPO) for measurement of hemoglobin oxygen saturation in arterial blood and pulse rate (PR) in anesthetized dogs breathing 100% O2.
29 healthy client-owned anesthetized dogs undergoing various surgical procedures.
In randomized order, each of 7 FPOs or a reference pulse oximeter (PO) was applied to the tongue of each intubated anesthetized dog breathing 100% O2. Duplicate measurements of oxygen saturation (Spo2) and PR were obtained within 60 seconds of applying an FPO or PO. A nonparametric version of Bland-Altman analysis was used. Coefficient of repeatability was the interval between the 5th and 95th percentiles of the differences between duplicate measurements. Bias was the median difference, and the limits of agreement were the 5th and 95th percentiles of the differences between each FPO and the PO. Acceptable values for the coefficient of repeatability of Spo2 were ≤ 6%. Agreements were accepted if the limits of agreement had an absolute difference of ≤ ± 3% in Spo2 and relative difference of ≤ ± 10% in PR.
Coefficient of repeatability for Spo2 was acceptable for 5 FPOs, but the limits of agreement for Spo2 were unacceptable for all FPOs. The limits of agreement for PR were acceptable for 2 FPOs.
CONCLUSIONS AND CLINICAL RELEVANCE
Results suggested that some FPOs may be suitable for accurately monitoring PRs of healthy anesthetized dogs breathing 100% O2, but mild underestimation of Spo2 was common.
Case Description—5 horses were evaluated because of decreased appetite, weight loss, fever, cough, tachypnea, and respiratory distress.
Clinical Findings—Tachycardia, tachypnea, increased respiratory effort, lethargy, fever, poor body condition, and nasal discharge were detected in various combinations on initial physical examination. Evaluation of the lower portion of the respiratory tract via radiography and ultrasonography revealed a severe nodular interstitial pattern. Histologic examination of lung tissue revealed interstitial expansion of alveolar parenchyma with collagen, intraluminal accumulation of neutrophils and macrophages within the alveoli, and occasional intranuclear inclusion bodies within alveolar macrophages. Equine herpesvirus type 5 was detected in samples of lung tissue, bronchoalveolar lavage fluid, or both via polymerase chain reaction assay in all cases. A diagnosis of equine multinodular pulmonary fibrosis (EMPF) was established.
Treatment and Outcome—Horses were provided supportive treatment and were administered a variety of medications including corticosteroids and acyclovir. Two horses survived and returned to their previous level of activity. Three horses were euthanized because of either deterioration of clinical condition (n = 2) or failure to improve within 4 weeks of initiation of treatment (1).
Clinical Relevance—EMPF should be considered as a differential diagnosis for adult horses with interstitial pneumonia and should be suspected on the basis of characteristic radiographic, ultrasonographic, and histopathologic findings. Equine herpesvirus type 5 is found in association with EMPF; although the exact pathogenic role this virus plays in EMPF is unknown, equine herpesvirus type 5 may be an etiologic agent or cofactor in the development of EMPF.