Computed tomographic diagnosis of a common bile duct abscess and secondary extrahepatic biliary duct obstruction in a potbelly pig.

A potbelly pig was evaluated for anorexia and icterus. Clinicopathologic abnormalities suggested an active inflammatory hepatobiliary process. Ultrasound and CT of the abdomen revealed an extrahepatic biliary obstruction of the common bile duct (CBD). Surgical exploration and choledochotomy revealed a markedly dilated CBD containing a large volume of intraluminal inspissated biliary material. This case report describes the imaging findings of an extrahepatic biliary obstruction secondary to abscessation within the CBD in a pig.

Pharmacokinetics and pharmacodynamics of oral and intravenous metoprolol tartrate in clinically healthy horses.

Cardiac drugs with defined pharmacological parameters in horses are limited. The objective of this study was to characterize the pharmacokinetic properties and cardiovascular effects of intravenous and oral metoprolol tartrate (MET) in horses. In a 2-period randomized cross-over design, MET was administered IV (0.04 mg/kg) and PO (6 mg/kg) once to six healthy adult horses. Horses were monitored via continuous telemetry and non-invasive blood pressure (NIBP). Blood samples were serially collected for 72 h post-administration, and concentrations were determined by LC-MS/MS. Pharmacokinetics were modeled using a 3-compartment model and non-linear least squares regression. Median (range) MET concentration was 110 (40.1-197) ng/ml collected 1 min (0.0167 h) after a bolus IV administration. Maximum concentration (Cmax ) after PO administration was 2135 (1590-4170) ng/ml at 0.5 (0.25-0.5) hours. Oral bioavailability was 54% (17-100%). Median apparent volume of distribution was 0.39 (0.17-0.58) l/kg, clearance was 12.63 (11.41-18.94) ml/kg/min, and elimination half-life was 21.1 (7.46-34.36) minutes. No clinically relevant effects of IV or PO metoprolol were noted on cardiac rhythm or NIBP. Sweating was the most common side effect. The metoprolol doses used in this study achieve plasma concentrations reported to achieve ß-blockade in humans.

Treatment and outcome of eight horses with limb cellulitis and septic tendonitis or desmitis.

OBJECTIVE: To report the clinical features, treatment, and outcome in horses with cellulitis and concurrent septic tendonitis and/or desmitis. STUDY DESIGN: Short case series. METHODS: Medical records from 2000 to 2019 were reviewed, identifying horses with cellulitis and concurrent septic tendonitis and/or desmitis based on sonographic examination and positive bacterial culture. Signalment, ultrasonographic results, bacterial culture, treatment, duration of hospitalization, and complications were recorded. Long-term outcome data were obtained from follow-up examinations and/or telephone interviews. Successful outcome was defined as return to intended use. RESULTS: Eight horses met the inclusion criteria. All infections occurred in hindlimbs, with septic suspensory ligament in six of eight horses, and septic superficial digital flexor tendon in one of eight horses. Surgical debridement was performed in six of eight horses. All horses were treated with systemic and regional intravenous antimicrobials and were discharged from the hospital. Long-term follow-up was available in seven of eight horses. Of these, four horses returned to their intended athletic function, two horses returned to their intended function as a broodmare or pasture pet, and one horse is still rehabilitating. CONCLUSION: Septic tendonitis or desmitis is a rare but possible sequela of limb cellulitis. Based on the findings in this study, prognosis for return to athletic function is fair to good for horses diagnosed with cellulitis and concurrent septic tendonitis or desmitis.

Evaluation of the use of portable ultrasonography to determine pregnancy status and fecundity in bonnethead shark Sphyrna tiburo.

This study examined the usefulness of portable ultrasonography in accurately predicting pregnancy and fecundity in the bonnethead shark Sphyrna tiburo by comparing ultrasound-obtained data with those obtained from animal dissection, the gold standard for elasmobranch reproduction studies. Mature female S. tiburo (n = 66) were collected throughout the period of reproduction and examined via portable ultrasonography using two different ultrasound transducers (8-5 MHz linear array transducer and a 5.0-2.5 MHz curvilinear array transducer) to determine pregnancy status and fecundity. Ultrasound-derived data were compared with validated assessments of pregnancy and litter size obtained using animal dissection to determine the level of agreement between the two approaches. Overall, there was strong agreement (90.9%) between pregnancy determinations obtained using ultrasonography and dissection. However, the effectiveness of portable ultrasonography in accurately determining specific stages of maturity and pregnancy differed slightly between transducer types (linear = 61.3%; curvilinear = 88.9%). Measurements of fecundity also agreed well between ultrasonography and dissection and there were no significant differences between mean fecundity estimates obtained using the two methods. In general, portable ultrasonography was found to be a good alternative to lethal sampling and animal dissection in obtaining reproductive data critical for the management and conservation of elasmobranchs. Special attention should be given to factors that can influence the reliability of ultrasound-derived data such as transducer type, embryo size and sound wave interference due to gut contents.

Ultrasound-guided caudal cervical articular process arthrocentesis is accurate in live horses with and without arthropathy.

BACKGROUND: Cervical articular process joint (CAPJ) therapy is advocated for horses with neck disorders. Several ultrasound-guided CAPJ techniques have been described in cadaver studies with 72%-89% intra-articular injection accuracy; however, the CAPJ injection accuracy in clinical equine practice has not been extensively reported. OBJECTIVES: To describe a modified cranial approach for ultrasound-guided caudal CAPJ injections, to investigate the accuracy of this CAPJ injection technique in live horses, and to assess the effect of CAPJ injection location, laterality, operator, and radiographic CAPJ enlargement on injection accuracy. STUDY DESIGN: Retrospective case study. METHODS: Medical records of adult horses in which ultrasound-guided caudal (C4-T1) CAPJ injections were performed using a modified cranial approach between November 2006 and December 2020 were reviewed. Radiographic images of caudal cervical vertebrae were assessed by a blinded radiologist and the degree of CAPJ enlargement was graded using a previously described grading system (Rgrade 1-5b). Ultrasound-guided caudal CAPJ injection accuracy was determined by synovial fluid retrieval during an individual CAPJ injection. Statistical analysis was performed using mixed-effects multivariable logistic model to evaluate the association of CAPJ injection accuracy and the CAPJ injection location, Rgrade, laterality (right, left), and operator. RESULTS: The study included 149 horses with 177 hospital admissions. Synovial fluid was obtained from 586/658 (89.1%) caudal CAPJs using modified cranial ultrasound-guided approach for CAPJ injections. C6-C7 CAPJ injections had 7-fold higher likelihood (OR = 6.78, 95% CI: 1.67-27.52; p = 0.007) of synovial fluid retrieval compared with C4-C5 CAPJ injections. Operator, CAPJ injection side (left, right), and degree of radiographic CAPJ enlargement did not have significant effects on the success of synovial fluid retrieval from ultrasound-guided caudal CAPJ injections. MAIN LIMITATIONS: Retrospective study design. CONCLUSIONS: Intra-articular ultrasound-guided caudal CAPJ injections using a modified cranial approach can be performed accurately in live horses with and without CAPJ arthropathy.

Twenty-four hour continuous transvenous temporary right ventricular pacing in healthy horses.

BACKGROUND: The ability to perform transvenous temporary cardiac pacing (TV-TP) is critical to stabilize horses with symptomatic bradyarrhythmias. Reports of successful TV-TP in horses are limited, and only briefly describe short-term pacing. OBJECTIVE: To describe temporary, medium-term (24 h) transvenous right ventricular pacing in awake horses using a bipolar torque-directed pacing catheter. ANIMALS: Six healthy adult institutional teaching horses. METHODS: Prospective experimental study with 2 immediately successive TV-TP lead placements in each horse with a target location of the RV apex. One placement was performed primarily with echocardiographic guidance and 1 primarily with fluoroscopic guidance. In all placements, corresponding images were obtained with both imaging modalities. Horses were then paced for 24 h, unrestricted in a stall with continuous telemetric ECG monitoring. Echocardiographically determined lead position, episodes of pacing failure in the preceding 6 h, and pacing thresholds were recorded every 6 h. Pacing failure was defined as a period of loss of capture longer than 20 s. RESULTS: Pacing leads were placed with both guidance methods and maintained for 24 h with no complications. Two horses with leads angled caudally in the right ventricular apex had no pacing failure, the remaining 4 horses had varying degrees of loss of capture. Leads located in the right ventricular apex had longer time to pacing failure and lower capture thresholds P < 0.05. CONCLUSIONS AND CLINICAL IMPORTANCE: Medium-term TV-TP is feasible and has potential for stabilization of horses with symptomatic bradyarrhythmias. Lead position in the right ventricular apex appears optimal. Continuous ECG monitoring is recommended to detect pacing failure.

Detection of two equine trisomies using SNP-CGH.

Chromosomal aberrations in the horse are known to cause congenital abnormalities, embryonic loss, and infertility. While diagnosed mainly by karyotyping and FISH in the horse, the use of SNP array comparative genome hybridization (SNP-CGH) is becoming increasingly common in human diagnostics. Normalized probe intensities and allelic ratios are used to detect changes in copy number genome-wide. Two horses with suspected chromosomal abnormalities and six horses with FISH-confirmed aberrant karyotypes were chosen for genotyping on the Equine SNP50 array. Karyotyping of the first horse indicated mosaicism for an additional small, acrocentric chromosome, although the identity of the chromosome was unclear. The second case displayed a similar phenotype to human disease caused by a gene deletion and so was chosen for SNP-CGH due to the ability to detect changes at higher resolutions than those achieved with conventional karyotyping. The results of SNP-CGH analysis for the six horses with known chromosomal aberrations agreed completely with previous karyotype and FISH analysis. The first undiagnosed case showed a pattern of altered allelic ratios without a noticeable shift in overall intensity for chromosome 27, consistent with a mosaic trisomy. The second case displayed a more drastic change in both values for chromosome 30, consistent with a complete trisomy. These results indicate that SNP-CGH is a viable method for detection of chromosomal aneuploidies in the horse.

Multiple Sex Cord-stromal Tumors in a Standardbred Stallion Testis.

A 12-year-old Standardbred stallion presented with a 5-month history of a growing mass in the left testis as well as an overall decrease in left testicular size. Palpation and ultrasonography of the left testis revealed a firm, hypoechoic, clearly delineated soft tissue mass in the craniolateral portion of the testis that measured 2.5 × 2.3 × 1.9 cm. Two smaller, hypoechoic regions also were visible ultrasonographically in the left testis, suggesting the presence of multifocal/multicentric neoplasia. The affected testis was very small (testicular volume of 40.3 cm3). The right testis was significantly larger (144.3 cm3), and the parenchyma was ultrasonographically normal. Due to the concern that these findings could indicate the presence of a more aggressive tumor type, unilateral orchiectomy was performed. Multiple soft tissue masses were identified grossly, and histopathologic evaluation identified the larger mass as a Sertoli cell tumor and the two smaller masses as mixed sex cord-stromal tumors with Sertoli cell and Leydig cell differentiation. To our knowledge, this the first report of concurrent Sertoli cell and mixed sex cord-stromal tumors in a single descended equine testis.

Onchocerca sp. in an imported Zangersheide gelding causing suspensory ligament desmitis.

A 5-year-old imported Zangersheide gelding was evaluated for SC swellings over both forelimbs and lameness localized to the distal metacarpus. Ultrasound examination of the SC masses was compatible with verminous granulomas. Linear hyperechoic foci were present within the suspensory ligament branches of both forelimbs, suggestive of ligamentous parasitic infiltrates. A diagnosis of onchocerciasis was confirmed on biopsy of a SC mass. The gelding was treated with ivermectin and a tapering course of PO dexamethasone but was eventually euthanized. Necropsy confirmed the presence of SC eosinophilic granulomas and degenerative suspensory ligament desmitis, both with intralesional nematodes. Given the location and appearance of the nematode, a diagnosis of Onchocerca sp., most likely O. reticulata, was made. Onchocerciasis should be included as a differential diagnosis for multifocal suspensory ligament desmitis with these sonographic characteristics when paired with SC masses in imported European Warmbloods.

Effect of intraperitoneal PERIDAN™ concentrate adhesion reduction device on clinical findings, infection, and tissue healing in an adult horse jejunojejunostomy model.

OBJECTIVE: To evaluate the effect of PERIDAN™ Concentrate on clinical findings, infection, and tissue healing in adult horses undergoing celiotomy and jejunojejunostomy. STUDY DESIGN: Block randomized blinded experimental in vivo study. ANIMALS: Adult horses (n = 12). METHODS: Horses had jejunojejunostomy at 2 sites and were administered 5 L of diluted PERIDAN™ Concentrate (6 horses) or Lactated Ringer's Injection (LRS) control intraperitoneally (6 horses) before body wall closure. Postoperative monitoring comprised physical examinations, serial hematology, coagulation and chemistry panels, and ultrasonographic examination. Horses were euthanatized 10 days postoperatively. Anastomoses and linea alba incisions were tested for mechanical strength; and tissue healing, inflammation, and infection were assessed by histological evaluation. Data were analyzed using a mixed model ANOVA. Level of significance was P < .05. RESULTS: No physical examination differences were observed between groups. Statistically significant differences were observed in leukocyte and neutrophil counts, prothrombin time, antithrombin III activity, intestinal bursting pressures, and histologic healing grade in the mid region of the linea alba. These differences were minimal, and of no observable clinical significance. Other blood variable and histologic differences between groups were not significant. CONCLUSIONS: PERIDAN™ Concentrate was safely administered intraperitoneally to healthy horses undergoing celiotomy and anastomosis.

Sonographic appearance of the late gestation equine fetal intestine.

Variable gestation length in the mare poses a challenge for determination of fetal readiness for birth. The objectives of this study were to describe sonographic characteristics of the fetal GI tract in the late gestation mare and identify changes that occur with progressing fetal maturity. Based on these characteristics, a grading scale modeled after the existing human and canine scoring system was developed. Weekly sonographic examination of the fetus by one observer beginning 2-3 weeks prior to a calculated due date of 330 days was performed. Fetal assessment included; presence of stomach rugae, bowel segment definition (uniform echogenic, some defined, clearly defined), bowel segment dilation (none, segmental dilation), intestinal contents (none, mixed echogenicity) and peristalsis (none, occasional, every 3 s, continuous). Based on these characteristics a phase was assigned to the GI tract (1-5). Phase 1 was defined as a uniform echogenic grey area caudal to the diaphragm. The differentiation of Phase 2-5 was based primarily on the frequency of peristalsis, with Phase 2 exhibiting no peristalsis, Phase 3 exhibiting occasional peristalsis, Phase 4 exhibiting peristalsis every 3 s and Phase 5 exhibiting continuous peristalsis. Only data from mares with a normal parturition and healthy foals were included in the statistics (N = 10). Associations amongst sonographic fetal GI characteristics and days prepartum were validated using a simulation-based bootstrap approach with 1000 replicates using Stata 14. Stomach rugae, peristalsis, intestinal contents, tail head relaxation and udder development were all highly correlated with days prepartum. Using a multiple linear regression model, tail head relaxation and peristalsis predicted days prepartum with a 95% CI ±â€¯6 days. The same model predicted days prepartum with a 95% CI ±â€¯4 days when day of gestation, tail head relaxation and peristalsis were included as variables. Based on these findings, characterization of the fetal GI tract could provide valuable information concerning the maturity of the equine fetus. Further studies are needed comparing high risk mares to normal mares before this information could be used with confidence in the clinical setting.

Transrectal ultrasonographic characterization of the accessory sex glands, pelvic urethra, and ureters in normal geldings.

Transrectal ultrasound of the internal urogenital tract may be used to aid in the diagnosis of reproductive tract and urinary tract pathology in both stallions and geldings. Abnormalities of the accessory sex glands of geldings are uncommon, although prostatic masses have recently been described in adult geldings presenting with dysuria, stranguria, and/or hematuria. The purpose of this study was to describe the normal ultrasonographic features and sizes of the accessory sex glands, caudal ureters, and pelvic urethra in clinically normal geldings. Eleven healthy geldings with no history of urogenital tract pathology were evaluated by a single observer experienced in ultrasound of the stallion accessory sex glands. The ultrasonographic appearance, relative anatomic relationships and sizes of the accessory sex glands, caudal ureters, and pelvic urethra were investigated using both rectal linear array and microconvex array transducers. Summary statistics including mean, standard error, confidence intervals, and range were calculated for each structure. There were no statistically significant differences in measurements between the left and right sides of paired structures or between measurements obtained with different transducers. Fluid was present in the seminal vesicles of 7 of 9 subjects. Midline cysts of the urethra as well as bulbourethral gland and prostatic cysts were identified. The normal reference ranges defined in this study will be useful in the clinical evaluation of geldings with suspected internal urogenital tract pathology.

Evaluation of coagulation and fibrinolysis in horses with atrial fibrillation.

OBJECTIVE: To evaluate horses with atrial fibrillation for hypercoagulability; plasma D-dimer concentrations, as a marker of a procoagulant state; and a relationship between coagulation profile results and duration of atrial fibrillation or presence of structural heart disease. DESIGN: Case-control study. ANIMALS: Plasma samples from 42 horses (25 with atrial fibrillation and 17 without cardiovascular or systemic disease [control group]). PROCEDURES: Results of hematologic tests (ie, plasma fibrinogen and D-dimer concentrations, prothrombin and activated partial thromboplastin times, and antithrombin activity) in horses were recorded to assess coagulation and fibrinolysis. Historical and clinical variables, as associated with a hypercoagulable state in other species, were also recorded. RESULTS: Horses with atrial fibrillation and control horses lacked clinical signs of hypercoagulation or thromboembolism. Compared with control horses, horses with atrial fibrillation had significantly lower antithrombin activity. No significant differences in plasma fibrinogen and D-dimer concentrations and prothrombin and activated partial thromboplastin times existed between horse groups. In horses with atrial fibrillation versus control horses, a significantly larger proportion had an abnormal plasma D-dimer concentration (10/25 vs 2/17), test results indicative of subclinical activated coagulation (18/25 vs 6/17), or abnormal coagulation test results (25/121 vs 7/85), respectively. CONCLUSIONS AND CLINICAL RELEVANCE: Horses with atrial fibrillation did not have clinical evidence of a hypercoagulable state, but a higher proportion of horses with atrial fibrillation, compared with control horses, did have subclinical activated coagulation on the basis of standard coagulation test results.

Myocardial insult and arrhythmias after acute hemorrhage in horses.

OBJECTIVE: The objectives of this investigation were to: (1) Determine if acute hemorrhage is associated with increased plasma cardiac troponin I (cTnI) concentration or cardiac arrhythmias, (2) to describe the types of arrhythmias and their clinical course in horses following acute hemorrhage, (3) to determine the ability of clinical or clinicopathological variables to predict an increase in cTnI concentration and the presence of arrhythmias, and (4) to determine the associations of cTnI and cardiac arrhythmias with outcome. DESIGN: Prospective observational study. SETTING: Large animal veterinary teaching hospital. ANIMALS: Eleven client-owned adult horses admitted for treatment of acute hemorrhage (HG) and 4 adult horses undergoing controlled blood collection (BDG). METHODS: Serial cTnI concentrations were measured and continuous ECGs were obtained from the HG and BDG groups. Statistical tests were used to determine associations among acute hemorrhage and plasma cTnI concentrations, the presence of cardiac arrhythmias, clinicopathologic data (heart rate [HR], packed cell volume [PCV], total plasma protein [TPP], plasma lactate, and plasma creatinine concentrations), and outcome. RESULTS: Plasma cTnI concentration and ECG were within reference intervals at all time points in the BDG. All horses in the HG had increased cTnI (ranging from 0.1-29.9 ng/mL). Arrhythmias were detected in 8 of these horses. There was an association between acute hemorrhage and increased cTnI (P = 0.004, ρ = 0.77), and the presence of arrhythmias (P = 0.026, ρ = 0.64). There were associations among plasma cTnI concentration and the presence of arrhythmias (P = 0.005), arrhythmias requiring treatment (P = 0.036), and poor outcome (P = 0.024). CONCLUSIONS: Acute hemorrhage results in myocardial injury that can be detected by measuring cTnI concentration. Arrhythmias were frequent in hospitalized horses following acute hemorrhage.

Hypertensive cardiomyopathy in horses: 5 cases (1995-2011).

OBJECTIVE: To describe the prognosis and clinical, echocardiographic, and pathological features of hypertensive cardiomyopathy in horses. DESIGN: Retrospective case series. ANIMALS: 5 horses with cardiac hypertrophy and systemic hypertension. PROCEDURES: Demographics, history, physical and cardiological examination findings, diagnosis, clinical progression, prognosis, and pathological findings were obtained from medical records. RESULTS: The primary diagnosis was chronic laminitis in 3 horses and chronic renal failure in 2. Persistent tachycardia, hypertension, chronic laminitis, or a combination of these prompted the cardiac evaluations. Blood pressure values (median [range]), measured noninvasively, were determined as 190 mm Hg (183 to 261 mm Hg) for systolic pressure, 126 mm Hg (100 to 190 mm Hg) for diastolic pressure, and 155 mm Hg (126 to 222 mm Hg) for mean pressure. No arrhythmias were reported. For the left ventricle, all horses had increased relative wall thickness, mean wall thickness, and ventricular mass. The interventricular septum was thickened at end diastole (n = 5) and in peak systole (4). The left ventricular internal diameter was small at end diastole (n = 4) and in peak systole (3). The left ventricular free wall was thickened at end diastole (n = 3) and in peak systole (4). No associations between blood pressure and variables consistent with hypertrophy were detected. All horses were euthanized because of the grave prognosis of the primary diseases. All 3 horses that underwent postmortem evaluation had cardiovascular abnormalities. CONCLUSIONS AND CLINICAL RELEVANCE: Hypertensive cardiomyopathy should be considered as a comorbid diagnosis in horses with laminitis or chronic renal failure. Information about the development, progression, reversibility, importance of early detection, and long-term sequelae of this condition is needed.

Effect of general anesthesia on plasma cardiac troponin I concentrations in healthy horses.

OBJECTIVE: To evaluate the effect of general anesthesia on plasma cTnI concentrations in horses. ANIMALS, MATERIALS AND METHODS: Thirty-two horses undergoing general anesthesia and either elective surgery or MRI without surgery were prospectively studied. Twenty-nine horses (22 surgical, 7 imaging) completed the study. Plasma cTnI concentrations were determined prior to anesthesia and at 6, 12 and 24 h following discontinuation of the inhalant anesthetic. RESULTS: All horses had cTnI values within the reference range at all time points. Six horses (21%) developed detectable cTnI 6 or 12 h following anesthesia. Risk factors for detectable cTnI include increasing age and dorsal recumbency. Horses with detectable cTnI had significantly lower mean and diastolic arterial blood pressures than those without detectable cTnI. CONCLUSION: Uncomplicated general anesthesia with or without surgery does not result in cardiac troponin I elevations above the reference range in the first 24 h postoperatively.