Objective—To evaluate the sensitivity and specificity of direct digital abdominal radiography for the diagnosis of enterolithiasis in equids and to assess the effect of the number and anatomic location of enteroliths and gas distention of the gastrointestinal tract on diagnostic sensitivity of the technique.
Design—Retrospective case series.
Sample Population—238 horses and ponies ≥ 1 year old that underwent digital abdominal radiography with subsequent exploratory celiotomy or postmortem examination.
Procedures—For each case, 3 reviewers independently evaluated radiographic views. Radiographic images were evaluated for presence or absence and location of enteroliths and the degree of gas distention. Signalment, definitive diagnosis based on exploratory celiotomy or postmortem examination findings, and number and anatomic location of enteroliths were obtained from the medical records.
Results—70 of the 238 (29.4%) equids had confirmed enterolithiasis. With regard to diagnosis of enterolithiasis via digital radiography, overall sensitivity and specificity for the 3 reviewers were 84% and 96%, respectively. Sensitivity was lower for small colon enteroliths (61.5%) than for large colon enteroliths (88.9%) and was negatively affected by gas distention of the gastrointestinal tract. Sensitivity was not affected by the number of enteroliths.
Conclusions and Clinical Relevance—Sensitivity and specificity of digital radiography for the diagnosis of large colon enterolithiasis in equids was high. Sensitivity of digital radiography for detection of small colon enteroliths was lower than that for large colon enteroliths, but was higher than that typically associated with computed radiography. In geographic regions in which enterolithiasis in equids is endemic, digital abdominal radiography could be used as a diagnostic test for equids with colic.
Objective—To determine the incidence and type of alterations in heart rate (HR), peak systolic blood pressure (PSBP), and serum biochemical variables (total bilirubin, BUN, and creatinine concentrations) associated with IV administration of ionic-iodinated contrast (IIC), nonionic-iodinated contrast (NIC), and gadolinium dimeglumine (GD) contrast media in anesthetized dogs.
Procedures—HR and PSBP were recorded at 5-minute intervals for 20 minutes for untreated control dogs and dogs that received IIC, NIC, or GD contrast medium. The development of an HR of < 60 beats/min or > 130 beats/min that included a ≥ 20% change from baseline was considered a response. The development of PSBP of < 90 mm Hg or > 160 mm Hg that included a ≥ 20% change from baseline was considered a response. Pre- and postcontrast serum biochemical values were recorded.
Results—Of dogs receiving IIC medium, 3% (3/91) had a response in HR and 4% (4/91) had a response in PSBP at ≥ 1 time points. None of the dogs receiving NIC medium had a response in HR; 1 of 16 had a response in PSBP. Of dogs receiving GD contrast medium, 1% (1/92) had a response in HR and 4% (4/92) had a response in PSBP. Of control dogs, 2% (2/81) had a response in HR and 4% (3/81) had a response in PSBP. No serum biochemical alterations were observed.
Conclusions and Clinical Relevance—IV administration of contrast media in anesthetized dogs caused moderate bradycardia, tachycardia, hypotension, or hypertension.
Objective—To determine the incidence and type of alterations in heart rate (HR), peak systolic blood pressure (PSBP), and serum biochemical variables (serum total bilirubin, BUN, and creatinine concentrations) associated with IV administration of ionic-iodinated contrast (IIC), nonionic-iodinated contrast (NIC), and gadolinium (GD) contrast media in anesthetized cats.
Procedures—HR and PSBP were recorded at 5-minute intervals for 20 minutes for untreated control cats and cats that received IIC, NIC, or GD contrast medium. The development of HR < 100 beats/min or > 200 beats/min that included a ≥ 20% change from baseline was considered a response. The development of PSBP of < 90 mm Hg or > 170 mm Hg that included a ≥ 20% change from baseline was considered a response. Pre- and postcontrast serum biochemical values were recorded.
Results—Of cats receiving IIC medium, 2% (1/60) had a response in HR at ≥ 1 time point. Of cats receiving IIC medium, 7% (4/60) had a response in PSBP. None of the cats receiving NIC medium had a response in HR; 2 of 12 had a response in PSBP. Of cats receiving GD contrast medium, 6% (5/83) had a response in HR and 8% (7/83) had a response in PSBP. None of the control cats had a response in HR or PSBP. No serum biochemical alterations were observed.
Conclusions and Clinical Relevance—IV administration of iodine and GD contrast media in anesthetized cats was associated with changes in HR and PSBP.
Objective—To evaluate the sensitivity and specificity of abdominal computed radiography (CR) for the diagnosis of enterolithiasis in horses and to examine how these parameters are affected by the number and anatomic location of enteroliths and by gas distension of the gastrointestinal tract.
Design—Retrospective case series.
Animals—Horses ≥ 1 year old that underwent abdominal CR and subsequent exploratory laparotomy or postmortem examination.
Procedures—3 reviewers blinded to signalment, history, clinical signs, and diagnoses separately evaluated abdominal computed radiographs of horses included in the study. Each set of radiographs was evaluated for the presence or absence of enteroliths, the amount of gas distention, and the image quality. Signalment, definitive diagnosis on the basis of findings on exploratory laparotomy or postmortem examination, and the number and location of enteroliths were obtained from medical records.
Results—Of the 142 cases reviewed, 58.4% (83/142) had confirmed enterolithiasis. For the 3 reviewers, overall sensitivity was 85% and specificity was 93%. Sensitivity was lower for small colon enteroliths than for large colon enteroliths (50% and 94.5%, respectively) and was significantly affected by gas distention. Sensitivity was not significantly affected by the number of enteroliths.
Conclusions and Clinical Relevance—Computed radiography provided high sensitivity and high specificity for the diagnosis of enterolithiasis in horses. Caution should be exercised when the radiographic results are negative, as the sensitivity for small colon enterolithiasis was relatively low and gas distension negatively affected detection of enteroliths. Abdominal CR is indicated as a diagnostic test in horses examined for colic in geographic regions in which enterolithiasis is endemic.
Objective—To describe ultrasonographic landmarks for use in collection of CSF from the lumbosacral region in equids.
Animals—37 equids (27 with neurologic disease and 10 with nonneurologic disease).
Procedures—Standing equids (n = 17) were sedated with detomidine hydrochloride (0.006 to 0.01 mg/kg [0.003 to 0.005 mg/lb], IV) followed by butorphanol tartrate (0.01 mg/kg, IV) and restrained with a nose twitch for collection of CSF. The CSF was collected from 20 laterally recumbent equids (10 sedated and 10 immediately after euthanasia). Anatomic landmarks were identified ultrasonographically. Height at the dorsal point of the shoulders, body weight, depth of the spinal needle, number of attempts to collect CSF, and cytologic evaluation of CSF were recorded.
Results—Lumbosacral puncture cranial to the cranial border of the most superficial location of both tuber sacrale along the midline was consistently successful for CSF collection (35/37 equids). Two horses had anatomic abnormalities that precluded CSF collection. Mean number of attempts to collect CSF per animal was 1.1. Height and body weight were strongly correlated with needle depth for CSF collection. Pelvic and sacral displacement was observed in several laterally recumbent animals, which resulted in discrepancies of the midline between the cranial and caudal aspects of the vertebral column. In most equids, the spinal needle was aligned on the midline of the caudal aspect of the vertebral column.
Conclusions and Clinical Relevance—Ultrasonography was a useful aid for collection of CSF from the lumbosacral space and decreased the risk of repeated trauma and contamination in equids.
Objective—To define the reference range for laminar blood flow (BF) and vascular permeability (VPM) in horses without laminitis by use of dynamic contrast-enhanced computed tomography (CT).
Animals—9 adult horses that were not lame and had no abnormalities of the laminae or phalanges detectable via radiographic examination.
Procedures—Each horse was anesthetized by use of a routine protocol. Horses were placed in right or left lateral recumbency with the dependent forelimb in the CT gantry; only 1 limb of each horse was scanned. Serial 10-mm collimated transverse CT images were acquired at the same location every other second for 90 seconds during infusion of ionic, iodinated contrast medium. Custom software was used to estimate BF, VPM, and fractional vascular volume (FVV) in the dorsal, dorsomedial, and dorsolateral laminar regions.
Results—Among the 9 horses' forelimbs, mean ± SD dorsal laminar BF was 0.43 ± 0.21 mL•min−1•mL−1. Mean dorsomedial and dorsolateral laminar BFs were 0.26 ± 0.16 mL•min−1•mL−1 and 0.24 ± 0.16 mL•min−1•mL−1, respectively. Mean dorsal laminar VPM was 0.09 ± 0.03 mL•min−1•mL−1. Mean dorsomedial and dorsolateral laminar VPMs were 0.16 ± 0.06 mL•min−1•mL−1 and 0.12 ± 0.06 mL•min−1•mL−1, respectively. Mean dorsal laminar FVV was 0.63 ± 0.20 and dorsomedial and dorsolateral laminar FVV were 0.37 ± 0.14 and 0.34 ± 0.17, respectively.
Conclusions and Clinical Relevance—In horses, laminar BF, VPM, and FVV can be non-invasively measured by use of dynamic contrast-enhanced CT.
Objective—To estimate the prevalence of radiographic abnormalities (lesions) in Thoroughbred racehorses at 2-year-old in-training sales and determine whether these lesions and 1-furlong presale workout times were associated with subsequent racing performance.
Design—Retrospective cohort study.
Procedures—Repository radiographs of carpal, metacarpophalangeal and metatarsophalangeal (fetlock), stifle, and tarsal (hock) joints were examined. Horses with lesions were classified by lesion type and location. Race performance variables were compared between horses with and without lesions and between horses categorized by 1-furlong presale workout times (< or ≥ 11 seconds).
Results—299 horses had ≥ 1 lesion, and 654 had no lesion detected. Odds of starting a race and of earning money racing were lower for horses with any lesion and lower for horses with proximal phalangeal dorsoproximal articular margin chip fracture, proximal sesamoid bone fracture or sesamoiditis, or wedge-shaped central or third tarsal bones, compared with horses that had no lesion. For horses that raced, proximal phalangeal dorsoproximal articular margin chip fractures were associated with lower lifetime earnings, and flattening of the medial femoral condyle was associated with fewer 3-year-old racing starts, compared with values for horses that had no lesion. Horses with workout times < 11 seconds had greater odds of having lifetime starts, lifetime earnings, and maximum purse above threshold (median) values than did horses with slower workout times.
Conclusions and Clinical Relevance—No radiographic lesions prevented all affected horses from racing. Among horses that raced, few differences were found in performance for horses with and without lesions.
Objective—To define scintigraphic, physical examination, and scapular ultrasonographic findings consistent with bone fragility syndrome (BFS) in horses; develop indices of BFS severity; and assess accuracy of physical examination, scapular ultrasonography, and serum biomarkers for BFS diagnosis.
Design—Prospective case-control study.
Animals—48 horses (20 horses with BFS and 28 control horses).
Procedures—Horses underwent forelimb scintigraphic evaluation, physical examination, scapular ultrasonography, and serum collection. Scintigraphy was used as a reference standard to which physical examination, scapular ultrasonography, and concentrations of serum biomarkers (carboxy-terminal telopeptide of collagen crosslinks and bone-specific alkaline phosphatase activity) were compared for assessing accuracy in BFS diagnosis.
Results—A diagnosis of BFS was strongly supported on scintigraphy by ≥ 2 regions of increased radiopharmaceutical uptake, including 1 region in the scapular spine and 1 region in the scapular body or ribs; on physical examination by lateral bowing of the scapulae; and on ultrasonography by widening of the scapular spine. None of the tests evaluated were accurate enough to replace scintigraphy for mild disease; however, physical examination and scapular ultrasonography were accurate in horses with moderate to severe BFS. Serum biomarkers were not accurate for BFS diagnosis.
Conclusions and Clinical Relevance—Scintigraphy remained the most informative diagnostic modality for BFS, providing insight into disease severity and distribution; however, physical examination and scapular ultrasonographic abnormalities were diagnostic in horses with moderate to severe disease. Proposed severity indices classified the spectrum of disease manifestations. Clearly defined criteria for interpretation of diagnostic tests aid in the detection of BFS. Severity indices may be useful for assessing disease progression and response to treatment.
Objective—To determine whether CT provides unique information about the treatment or prognosis for horses with ethmoid hematoma (EH).
Design—Retrospective case series.
Animals—16 horses with EH.
Procedures—Horses with a diagnosis of EH that had undergone a diagnostic CT study were included. Clinical features, treatment, outcome, radiographic and CT images, and histologic specimens were reviewed.
Results—CT provided new diagnostic information that affected treatment in 10 of 16 horses. Bilateral disease occurred in 8 of 16 horses and was undetected in 5 horses prior to CT. Paranasal sinus involvement occurred in all horses, but was incompletely defined prior to CT in 7 of 16 horses. The sphenopalatine sinus was affected in 6 of 16 horses as detected on CT; 4 of 6 of these were bilaterally affected. Medical and surgical treatments were performed. Six of 10 horses had a successful outcome, with recurrence in 4 of 10. Five of 6 patients in which treatment addressed all lesion sites identified by CT had a successful outcome. Bilateral disease did not confer a poor prognosis when all affected sites were treated. Sphenopalatine sinus involvement may have been associated with recurrence.
Conclusions and Clinical Relevance—CT provided anatomic information that may facilitate effective treatment of horses with EH, particularly in patients with bilateral disease and paranasal sinus involvement. Computed tomography is recommended for patients in which the lesion cannot be viewed endoscopically, when sinus involvement or multifocal disease are suspected, or when the lesion has been unresponsive to treatment.