Detection of endotoxin in plasma of hospitalized diarrheic calves

OBJECTIVES

To investigate whether lipopolysaccharide (LPS) is present in plasma of calves with naturally occurring diarrhea. The second objective was to determine whether plasma [LPS] correlates with clinical, hematological, biochemical, and acid-base variables, and whether [LPS] differs between surviving and nonsurviving diarrheic calves.

DESIGN

Prospective observational study (January 2012-May 2014).

SETTING

Veterinary teaching hospital.

ANIMALS

Thirty-four calves <28 days old admitted for diagnosis and treatment of diarrhea and 30 healthy control calves.

MEASUREMENTS AND MAIN RESULTS

Admission demographics, physical examination, blood gas, biochemistry analysis, and outcome data were recorded. Plasma concentration of LPS was determined using a bovine LPS ELISA assay. Plasma [LPS] was detected in both healthy and diarrheic calves. Plasma [LPS] was significantly higher in diarrheic than healthy calves (median: 0.99 ng/mL; Interquartile range (IQR): 0.068, vs 0.88 ng/mL; 0.065 ng/mL, respectively; P < 0.001). Plasma [LPS] was higher in nonsurviving (1.04 ng/mL; 0.07 ng/mL) than in surviving calves (0.98 ng/mL; 0.022 ng/mL; P < 0.001). Plasma [LPS] was higher in beef (1.07 ng/mL; 0.182 ng/mL) than in dairy diarrheic calves (0.99 ng/mL; 0.022 ng/mL; P < 0.001). In diarrheic calves, plasma [LPS] correlated with [l-lactate] (r² = 0.496; P = 0.002); hypoglycemia (r² = -0.453; P = 0.007); increased unmeasured strong ions (r² = 0.332; P = 0.050), [Mg²⁺ ] (r² = 0.475; P = 0.004), and [phosphate] (r² = 0.468; P = 0.005), and increased aspartate aminotransferase activity (r² = 0.348; P = 0.003).

CONCLUSIONS

This study highlights a potential role of LPS in the pathogenesis of metabolic derangements such as hyperlactatemia, hypoglycemia, and increased concentration of unmeasured strong anions in diarrheic calves. Further investigation evaluating the effect of LPS on l-lactate and glucose metabolism in diarrheic calves is warranted.

Association of unmeasured strong ions with outcome of hospitalized beef and dairy diarrheic calves

Increased systemic concentrations of L-lactate and unmeasured strong ions (USI) are associated with an increased risk of mortality in human neonates and adults suffering from various diseases. This exploratory study aimed to investigate if values of certain acid-base parameters, especially L-lactate and USI, on admission to hospital are associated with mortality in diarrheic calves. Fifty-five calves < 28 days old admitted to 2 teaching hospitals for diagnosis and treatment of diarrhea were included. Admission demographic, physical examination, blood gas and biochemistry analysis, and outcome data were recorded. Admission acid-base values associated with outcome were assessed using multivariable regression modeling. Calves with elevated plasma L-lactate (OR: 1.30, 95% CI: 1.08 to 1.55; P = 0.005) and USI (OR: 1.40, 95% CI: 1.12 to 1.74; P = 0.003) at admission were more likely to die or to be euthanized. This study revealed that elevated concentrations of L-lactate and USI at admission were positively associated with mortality.

Acquired multiple acyl-CoA dehydrogenase deficiency and marked selenium deficiency causing severe rhabdomyolysis in a horse

This report describes a case of severe rhabdomyolysis in a pregnant mare associated with histopathologic and biochemical features of both selenium deficiency and acquired multiple acyl-CoA dehydrogenase deficiency (MADD) due to seasonal pasture myopathy (SPM). This case highlights the importance of assessing plasma selenium levels in horses with clinical signs of pasture myopathy as this deficiency may be a contributing or exacerbating factor.

Contribution of unmeasured anions to acid-base disorders and its association with altered demeanor in 264 calves with neonatal diarrhea

Background

The quantitative effect of strong electrolytes, unmeasured anions (UAs), pCO₂, and plasma protein concentrations in determining plasma pH and bicarbonate (HCO₃⁻) can be demonstrated using the physicochemical approach. Demeanor of calves with diarrhea is associated with acidemia, dehydration, and hyper‐d‐lactatemia.

Hypothesis

Unmeasured anions are a major factor influencing changes in plasma pH and HCO₃⁻ of calves with diarrhea and UAs and strong UAs, estimated by anion gap (AG) and strong ion gap (SIG), respectively, are more strongly associated with alteration of demeanor compared to other acid–base variables.

Animals

A total of 264 calves with diarrhea from two data sets (DS1 and DS2).

Methods

Retrospective study. Forward stepwise regression was performed to determine the relationship between measured pH or HCO₃⁻, and physicochemical variables. A two‐way ANOVA was performed to investigate the association between acid–base variables and attitude (bright, obtunded, and stuporous), posture (standing, sternal or lateral recumbency), and strength of suckling reflex (strong, weak, or absent).

Results

Increased strong UAs estimated by SIG was the most important contributor to changes in measured pH and HCO₃⁻ (DS1: r² 66 and 59%, DS2: 39 and 42%, P < .0001). SIG and AG were correlated to deteriorating calf demeanor for all three clinical scoring categories: attitude, posture, and suckle reflex (P < .0001).

Conclusion and Clinical Relevance

Elevated concentrations of strong UAs were the primary cause of acidemia and had an important influence on the demeanor of calves with diarrhea. These findings emphasize the importance of the calculation of UAs when evaluating acid–base abnormalities in calves.

Septic peritonitis and uroperitoneum secondary to subclinical omphalitis and concurrent necrotizing cystitis in a colt

A 15-day-old American Quarter horse colt was presented for depression and pyrexia. Peritonitis was diagnosed following peritoneal fluid analysis. Exploratory laparotomy revealed an area of focal necrosis over the dorsal wall of the urinary bladder leading to peritonitis and uroperitoneum. The affected area of the urinary bladder was resected and the peritonitis resolved with medical treatment.

Granulocytic anaplasmosis in a horse from Nova Scotia caused by infection with Anaplasma phagocytophilum

A 16-year-old Paint stallion was presented with intermittent fever, inappetance, lethargy, icterus, distal limb edema, and submandibular lymphadenopathy. The horse was native to Nova Scotia and had never left that province. Morulae were detected in granulocytes. Ananaplasma phagocytophilum infection was confirmed by serology and polymerase chain reaction (PCR). The horse responded to treatment with oxytetracycline.

Treatment of inflammatory airway disease in young standardbreds with interferon alpha

The effect of oral treatment with natural or recombinant human interferon alpha (HIA) on inflammatory airway disease in young standardbreds was assessed in a double-blind, randomized clinical trial. A total of 34 horses with nasal discharge, excess mucus in the trachea, and a persistent cough of at least 2 weeks' duration that interfered with training completed the trial. Horses were rested for 1 week and received oral treatment with either a saline placebo, recombinant human interferon alpha (rHIA; 90 U/horse/day), or natural human interferon alpha (nHIA: 50 U/horse/day) for 5 days. There was a significant decline in nasal discharge and cough scores in all groups and the apparent response rate was similar. However, significantly fewer horses relapsed within 2 weeks once treatment was ceased when interferon rather than placebo was used (P = 0.012). Seventeen of 22 horses treated with rHIA or nHIA were cough-free 4 weeks after treatment, compared with only 4 of 12 after treatment with the placebo. Treatment with oral interferon is a useful adjunct to rest in standardbreds with inflammatory airway disease.

Peritoneal fluid values and collection technique in young, normal calves

Peritoneal fluid from 10 healthy young male Holstein calves was analyzed three times (2 to 3 days, 12 to 15 days and 27 to 30 days) during the first month of life. A new technique for collection of peritoneal fluid from calves positioned in left lateral recumbency was developed. The technique was found to be reliable and without noticeable complications. Mean peritoneal fluid nucleated cell counts, red blood cell counts, and absolute counts for mononuclear cells, lymphocytes and eosinophils did not change significantly (P </= 0.05) over the first month of life. Mean peritoneal fluid protein concentrations were significantly (P </= 0.05) higher at the earliest sampling period compared to the latter two sampling times. The mean absolute neutrophil count in peritoneal fluid at the final sampling time was significantly (P </= 0.05) higher than in the earlier two sampling times. These changes were considered to be of equivocal importance. There was no significant (P </= 0.05) correlation between the calves' white blood cell counts and peritoneal fluid nucleated cell counts, or between absolute counts of similar cell types in peripheral blood and peritoneal fluid. Peritoneal fluid from the young calves in the present study had higher mean total nucleated cell counts and lower protein concentrations when compared non-statistically to peritoneal fluid values reported in the literature for older calves and mature pregnant cattle. The young calves also had lower mean absolute eosinophil counts and higher mean absolute neutrophil cell counts than those previously reported for older calves and mature cattle. It was concluded that use of data for peritoneal fluid values in older calves or mature cattle may be inappropriate for evaluating peritoneal fluid from younger calves.

Model to predict septicemia in diarrheic calves

The difficulty in distinguishing between septicemic and nonsepticemic diarrheic calves prompted a study of variables to predict septicemia in diarrheic calves, 28 days old that were presented to a referral institution. The prevalence of septicemia in the study population was 31%. Variables whose values were significantly different (P < .10) between septicemic and nonsepticemic diarrheic calves were selected using stepwise, forward, and backward logistic regression. Variables identified as potentially useful predictors were used in the final model‐building process. Two final models were selected: 1 based on all possible types of predictors (laboratory model) and 1 based only on demographic data and physical examination results (clinical model). In the laboratory model, 5 variables retained significance: serum creatinine > 5.66 mg/dL (> 500 μmol/L) (odds ratio [OR] = 8.63, P = .021), toxic changes in neutrophils ≥ 21 (OR = 2.88, P = .026), failure of passive transfer (OR = 2.72, P = .023), presence of focal infection (OR = 2.68, P = .024), and poor suckle reflex (OR = 4.10, P = .019). Four variables retained significance in the clinical model: age ≤ 5 days (OR = 2.58, P = .006), presence of focal infection (OR = 2.45, P = .006), recumbency (OR = 2.98, P = .011), and absence of a suckling reflex (OR = 3.03, P = .031). The Hosmer—Lemeshow goodness‐of‐fit chi‐square statistics for the laboratory and clinical models had P‐values of .72 and .37, respectively, indicating that the models fit the observed data reasonably well. The laboratory model outperformed the clinical model by a small margin at a predictabilty cutoff of 0.5, however, the predictive abilities of the 2 models were quite similar. The low sensitivities (39% and 40%) of both models at a predicted probability cutoff of 0.5 meant many septicemic calves were not being detected by the models. The specificity of both models at a predicted probability cutoff of 0.5 was .90%, indicating that .90% of nonsepticemic calves would be predicted to be nonsepticemic by the 2 models. The positive and negative predictive values of the models were 66–82%, which indicated the proportion of cases for which a predictive result would be correct in a population with a prevalence of septicemia of 31%.

Model to predict septicemia in diarrheic calves

The difficulty in distinguishing between septicemic and nonsepticemic diarrheic calves prompted a study of variables to predict septicemia in diarrheic calves <28 days old that were presented to a referral institution. The prevalence of septicemia in the study population was 31%. Variables whose values were significantly different (P < .10) between septicemic and nonsepticemic diarrheic calves were selected using stepwise, forward, and backward logistic regression. Variables identified as potentially useful predictors were used in the final model-building process. Two final models were selected: 1 based on all possible types of predictors (laboratory model) and 1 based only on demographic data and physical examination results (clinical model). In the laboratory model, 5 variables retained significance: serum creatinine > 5.66 mg/dL (>500 micromol/L) (odds ratio [OR] = 8.63, P = .021), toxic changes in neutrophils > or = 2+ (OR = 2.88, P = .026), failure of passive transfer (OR = 2.72, P = .023), presence of focal infection (OR = 2.68. P = .024), and poor suckle reflex (OR = 4.10, P = .019). Four variables retained significance in the clinical model: age < 5 days (OR = 2.58, P = .006), presence of focal infection (OR = 2.45, P = .006), recumbency (OR = 2.98, P = .011), and absence of a suckling reflex (OR = 3.03, P = .031). The Hosmer-Lemeshow goodness-of-fit chi-square statistics for the laboratory and clinical models had P-values of .72 and .37, respectively, indicating that the models fit the observed data reasonably well. The laboratory model outperformed the clinical model by a small margin at a predictabilty cutoff of 0.5, however, the predictive abilities of the 2 models were quite similar. The low sensitivities (39% and 40%) of both models at a predicted probability cutoff of 0.5 meant many septicemic calves were not being detected by the models. The specificity of both models at a predicted probability cutoff of 0.5 was >90%, indicating that >90% of nonsepticemic calves would be predicted to be nonsepticemic by the 2 models. The positive and negative predictive values of the models were 66-82%, which indicated the proportion of cases for which a predictive result would be correct in a population with a prevalence of septicemia of 31%.

Paranasal sinus cyst as a cause of stridor in a standardbred colt

Sinus cysts are epithelium-lined, fluid-filled cavities that can occur in the paranasal sinuses of horses. Extensive damage to the permanent tooth buds was a significant feature in this case. The sequellae of these abnormalities, although not apparent at the time of presentation, remain an important consideration for prognosis.

Comparison of efficacy of sulbactam: ampicillin to ampicillin and saline for treatment of experimentally induced Escherichia coli diarrhea in neonatal calves

A study was conducted to compare the efficacy of sulbactam: ampicillin (SAMP) (3.3:6.6 mg/kg body weight (BW), IM, q24 h) to that of ampicillin trihydrate (AMP) (6 mg/kg BW, IM, q24 h) and 0.9% saline (SAL) (3 mL IM, q24 h) for the treatment of diarrhea in calves induced by oral inoculation with Escherichia coli strain B44 (O9:K30:K99:H-). Treatment was initiated when severe diarrhea was noted (T0) and continued for at least 3 d; or for 24 h after clinical signs resolved; or for a maximum duration of 7 d. Starting at T0, calves were examined twice daily: appetite; rectal temperature (TEMP); and fecal consistency (FECAL), mental status (ATTD), eye position (EYE), and skin elasticity (SKIN) scores were recorded. Feces collected at T0 were submitted for bacteriology, electron microscopy, and parasitology. A complete blood count was performed at T0 and T3 (24 h after third treatment). Severely dehydrated, depressed, and anorexic calves were euthanized and considered mortalities. Cause of death was determined by post mortem examination. A total of 30 calves were included in the study. Three calves were excluded from final analysis. E. coli strain B44 was cultured from feces of all calves at T0. At T2 (24 h after second treatment) mean TEMP of SAMP calves was significantly higher (P < 0.05) than mean TEMP of SAL calves; EYE and SKIN scores of SAMP calves were significantly lower (P < alpha beta = 0.025) than those of SAL and AMP calves; and ATTD and FECAL scores of SAMP calves were significantly lower (P < alpha beta = 0.025) than in SAL calves. At T3, SAMP calves had significantly lower (P < 0.05) mean hematocrit than SAL calves and lower mean total plasma protein concentration than AMP and SAL calves. Mean fibrinogen concentration in SAMP calves at T3 was significantly lower (P < 0.05) than that of calves receiving either SAL or AMP. The number of surviving SAMP calves (10/10) was significantly higher (P < alpha beta = 0.025) than the number of surviving SAL calves (2/9), but not significantly different from the surviving AMP calves (3/8).

Radiographic diagnosis of calcific aortic arteriosclerosis in a Jersey cow

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Severe psoroptic mange and endoparasitism in a Nubian doe

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Congenital dyserythropoiesis and dyskeratosis in a polled Hereford calf

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Dysuria and stranguria associated with colonic ulceration and abdominal abscess in a horse

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Mixed papillary-polypoid cystitis in a heifer

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Diagnosis of avian tuberculosis in a horse by use of liver biopsy

A 15-month-old Appaloosa colt had pyrexia, weight loss, diarrhea, and dependent edema. Abnormal laboratory findings included anemia, hypoalbuminemia, and hyperglobulinemia. Activities of liver-specific enzymes in this colt were high. Analysis of a liver biopsy specimen resulted in a presumptive diagnosis of tuberculosis. We recommend that liver biopsy be used as a diagnostic procedure if the differential diagnosis in a horse includes avian tuberculosis or granulomatous enteritis, especially if serum activities of liver-specific enzymes are high.

Antemortem diagnosis of hepatic adenocarcinoma in a ewe

A 4-year-old ewe with weight loss, anorexia, and high liver enzyme activities was diagnosed at necropsy as having cholangiocellular carcinoma that had metastasized to kidneys, adrenal glands, heart, lungs, mediastinum, and peritoneal surface of the diaphragm. Cholangiocellular carcinoma is an uncommon neoplasm of sheep. Evaluation of liver tissue obtained via ultrasound-guided percutaneous liver biopsy had suggested an antemortem diagnosis of adenocarcinoma of the liver.

Enzootic ataxia and caprine arthritis/encephalitis virus infection in a New England goat herd [corrected]

Ataxia was diagnosed in kids from a New England goat herd. Concurrent infection with the caprine arthritis/encephalitis (CAE) virus contributed to the development of hind limb ataxia and weakness in one of the kids. Six kids from this herd had signs of hind limb ataxia and paralysis. Detailed evaluation of 2 of the affected kids revealed low liver and serum copper concentrations and spinal cord demyelination. One kid also had histologic changes in the CNS and lungs, compatible with a diagnosis of CAE. Serum copper concentration was determined in affected goat kids and their dams and was compared with serum copper concentration in clinically normal kids and their dams from the same herd. Serum copper concentration also was measured in dams and kids in a control herd that had no history of ataxia. The mean serum copper concentration in affected kids was 0.125 microgram/ml, compared with 0.45 microgram/ml in unaffected kid herdmates. Kids from the control herd had mean serum copper concentration of 0.6 microgram/ml. Mean serum copper concentration in dams of kids with neurologic signs also was low (0.25 microgram/ml), compared with that (0.5 microgram/ml) in dams of clinically normal kids of the affected herd and that (0.95 microgram/ml) in dams of kids of the control herd. Results of a serologic survey (by use of agar gel immunodiffusion) of the affected herd for CAE indicated that 69.5% of the goats were seropositive. Dietary copper intake was determined to be adequate in this goat herd; therefore, copper deficiency appeared to be conditioned by an interfering substance. However, a search for interfering substances was unrewarding.

Use of hepatobiliary scintigraphy to diagnose bile duct atresia in a lamb

A neonatal lamb was admitted with icterus, hypoglycemia, increased liver enzyme activities, and delayed sulfobromophthalein clearance. Biliary and pancreatic duct atresia were documented in this lamb at necropsy. Hepatobiliary scintigraphy was useful in reaching an antemortem diagnosis of bile duct obstruction. Hepatobiliary scintigraphy, using 1.5 mCi of 99m technetium-labeled acid, was performed on the affected lamb and on an age-matched control lamb. Using a large field-of-view camera equipped with a low-energy parallel-hole collimator, right ventral oblique images of the thorax and abdomen were obtained. Images were simultaneously recorded on microdot film by use of a dedicated nuclear medicine computer. In the control lamb, there was rapid clearance of radioactivity from the blood pool, coincident with obvious accumulation of radioactivity in the liver and followed by sequential accumulation in the intrahepatic biliary system, gallbladder, common bile duct, and small intestine. Results of the study in the affected lamb were characterized by prolonged blood-pool radioactivity without appreciable hepatic uptake and by excessive renal and urinary bladder activity in the later phases of the study. Hepatobiliary scintigraphy was a safe and non-invasive procedure that provided quantitative information about the degree of bile duct obstruction in the affected lamb.

Septicemic salmonellosis and suspected phenylbutazone toxicosis in an aged pony

A 16-year-old pony with signs of intermittent abdominal pain was treated with phenylbutazone in excess of the recommended dosage. Endoscopy revealed ulceration of the esophagus, stomach, and proximal portion of small intestine. The pony developed diarrhea. Salmonella typhimurium was isolated from the blood and feces. Treatment included fluids, trimethoprim-sulfadiazine, sucralfate, and ranitidine hydrochloride. The diarrhea resolved, as did the gastrointestinal ulceration. This case was unusual because septicemia with salmonellosis is an uncommon finding in adult equids. Also, complications commonly seen in neonatal septicemia (septic arthritis, nephritis, and hepatitis) were not observed. Phenylbutazone toxicosis and stress were considered possible causes for the gastrointestinal ulceration.

Pharmacokinetics of antipyrine, acetaminophen and lidocaine in fed and fasted horses

Previous studies demonstrated that plasma clearance of organic anions such as bilirubin, bile acid, sulfobromophthalein (BSP) and indocyanine green (ICG), was reduced from 36% (bile acid) to 55% (ICG) in fasted (3 days) horses. It is believed that a general decline in carrier-mediated hepatic uptake may have accounted for those changes. However, fasting may also affect hepatic blood flow, thereby contributing to reduced clearance of these compounds. In order to test this hypothesis, plasma clearance of antipyrine, acetaminophen and lidocaine, drugs known to be cleared by the liver yet not suspected of undergoing carrier-mediated hepatic uptake, were investigated in nine healthy adult mares (three horses/drug group) before and following a 3-day fast. Results demonstrate that fasting decreased clearance of organic anions from previous studies more than clearance of drugs used in these studies. In addition, clearance of lidocaine, the drug with the highest plasma clearance and therefore the drug most likely to be affected by reduced hepatic blood flow, was affected least by fasting. Therefore, reductions in clearance of these compounds due to fasting must not be due entirely to reductions in hepatic blood flow, but must also involve reductions in intrinsic hepatic clearance.

Antipyrine and lidocaine are cleared faster in horses than in humans: acetaminophen may be handled similarly

The following studies were designed to evaluate plasma elimination kinetics of intravenously administered antipyrine, acetaminophen and lidocaine among 9 healthy adult horses and 9 healthy drug-free humans (3 each per drug group), in order to compare potential species differences in drug-metabolizing ability. Acetaminophen is largely biotransformed in humans by hepatic glucuronide and sulfate conjugation, whereas both antipyrine and lidocaine are oxidized by hepatic microsomal mixed-function oxidases. Thus, plasma clearances of these drugs are thought to reflect differences in hepatic oxidative and conjugative activity, and possibly hepatic blood flow in the case of lidocaine. Results showed that mean (+/- SD, n = 3) acetaminophen clearance was similar in both horses (4.84 +/- 0.637 ml/min/kg) and humans (4.68 +/- 0.691 ml/min/kg). However, antipyrine clearance was 10 times greater in horses (5.83 +/- 2.21 ml/min/kg) than in humans (0.536 +/- 0.110 ml/min/kg), which may reflect enhanced hepatic microsomal activity in horses. Although lidocaine clearance in humans was similar to estimated hepatic blood flow (20.6 +/- 5.81 ml/min/kg), clearance in horses was more than 2 times greater (52.0 +/- 11.7 ml/min/kg). The cause of the higher clearance of lidocaine in horses (like dogs) remains unexplained, and may involve significant metabolism of lidocaine at extrahepatic, extravascular sites, for intravascular degradation and renal excretion of intact lidocaine in horses was negligible. Although precise biochemical mechanisms underlying pharmacokinetic parameters for these drugs in horses were not determined, it is nonetheless concluded from antipyrine results that horses may have an enhanced ability (compared with humans) to clear drugs from the circulation that are primarily metabolized in the liver by phase I oxidative reactions.(ABSTRACT TRUNCATED AT 250 WORDS)

Hepatobiliary transport of indocyanine green and sulfobromophthalein in fed and fasted horses

Fasting is associated with unconjugated hyperbilirubinemia in several species, including the horse. Studies in ponies showed that a 3-day fast decreased plasma clearance of bilirubin, cholic acid, and sulfobromophthalein (BSP). Since these organic anions are conjugated with different substrates, it is possible that observed differences in plasma clearance result from a general decrease in hepatic conjugating capacity during the animals' fasting. To test this hypothesis, the effects of a 3-day fast on plasma clearance of IV injected BSP (4.4 to 5.1 mg/kg), which is conjugated to glutathione, and indocyanine green (ICG; 0.8 to 1.1 mg/kg), which is not conjugated, were studied in 10 healthy horses and 2 ponies with diverted enterohepatic circulations (indwelling T tubes). Blood samples were obtained for 30 minutes after injection, and bile samples from ponies were obtained for 3 hours. Fasting increased plasma bilirubin concentration in all animals studied (from 1.03 +/- 0.337 mg/dl in control animals to 3.49 +/- 1.01 mg/dl in fasted animals). Kinetic values of ICG disappearance were determined from single exponential functions, and those for BSP were determined from both single and curvilinear (2-exponential) functions. Plasma clearance of BSP in fed horses (8.65 +/- 1.02 ml X min-1 X kg-1) was greater than clearance of ICG (3.54 +/- 0.67 ml X min-1 X kg-1), results similar to those reported in dogs, cats, rats, and persons. Fasting significantly decreased fractional plasma disappearance rate of both BSP (-36%) and ICG (-58%) and similarly reduced plasma clearance (BSP,-48%; ICG,-55%).(ABSTRACT TRUNCATED AT 250 WORDS)

Use of 111In-labeled autologous leukocytes to image an abdominal abscess in a horse

Indium 111-labeled autologous leukocytes were used to image an abdominal abscess in a horse with a palpable abdominal mass and history of Streptococcus equi infection. A focal area of radioactivity was identified in the location corresponding to the abscess. Imaging of this focal uptake was optimal 48 hours after injection. Similar scans obtained in 2 clinically normal horses revealed no evidence of focal radioactivity in this region. The cell labeling procedure gave acceptable labeling efficiency (87.5%) but an excessive number of damaged WBC, resulting in persistent lung radioactivity on all images. No adverse effects were noted. Radiation measured in the horse and its excreta were well within acceptable limits.