Case Description—4 horses with a history of neck pain, abnormal head carriage, and related inability to perform were examined. Cranial nuchal bursitis was diagnosed in 2 horses, and caudal nuchal bursitis was diagnosed in the other 2.
Clinical Findings—All 4 horses had prominent swelling in the region between the frontal bone and temporal fossa (ie, the poll) and abnormal head carriage. Ultrasonographic examination revealed fluid distention and synovial thickening of the cranial or caudal nuchal bursa in all 4 horses. Ultrasonography-guided aspiration of the affected region was performed successfully in 3 horses. Radiography revealed bony remodeling and mineralization over the dorsal aspect of the atlas in 1 horse and a radiolucency at the axis in another. Nuclear scintigraphy revealed an increase in radioisotope uptake at the level of C2 in 1 horse. Although a septic process was considered among the differential diagnoses in all horses, a septic process could only be confirmed in 1 horse.
Treatment and Outcome—All horses were refractory to conservative management consisting of intrabursal injection of anti-inflammatory medications. Bursoscopic debridement and lavage of the affected bursae resulted in resolution of the clinical signs in all horses, and they all returned to their intended use.
Clinical Relevance—Cranial and caudal nuchal bursitis, of nonseptic or septic origin, should be considered as a differential diagnosis in horses with head and neck pain. Horses undergoing surgical intervention consisting of nuchal bursoscopy have the opportunity to return to their original degree of exercise. (J Am Vet Med Assoc 2010;237:823–829)
Objective—To determine whether a single measurement of cortisol concentration can be used to monitor dogs receiving trilostane for hyperadrenocorticism.
Design—Controlled drug efficacy trial.
Animals—103 client-owned dogs.
Procedures—Results of ACTH stimulation tests before and during trilostane treatment were evaluated. Each cortisol concentration after ACTH stimulation was classified as indicative of excessive, acceptable, or inadequate control of adrenal gland function, as outlined by the trilostane manufacturer. Baseline cortisol concentrations before and during trilostane treatment were evaluated; target variables were defined, and sensitivity, specificity, and predictive values were determined.
Results—Results of 103 and 342 ACTH stimulation tests before and during treatment were evaluated. In this population, baseline cortisol concentrations ≥ 1.3 μg/dL accurately excluded excessive suppression (defined by cortisol concentration after ACTH stimulation < 1.5 μg/dL) in 254 of 259 (98%) dogs. In addition, baseline cortisol concentrations ≤ 2.9 μg/dL correctly excluded inadequate control (defined by cortisol concentration after ACTH stimulation > 9.1 μg/dL) in 200 of 211 (95%) dogs. During trilostane treatment, baseline cortisol concentrations between 1.3 and either 2.9 μg/dL or ≤ 50% of the pretreatment baseline cortisol concentration correctly predicted acceptable control of adrenal gland function in 147 of 168 (88%) dogs.
Conclusions and Clinical Relevance—Evaluation of a baseline cortisol concentration collected 4 to 6 hours after trilostane administration in dogs with hyperadrenocorticism provided clinically useful information about control of adrenal gland function. Many dogs receiving trilostane may be adequately monitored without the expense and inconvenience of an ACTH stimulation test. (J Am Vet Med Assoc 2010;237:801–805)
Objective—To compare signalment of horses with cervical vertebral malformation-malarticulation (CVM) with that of control horses and to describe results of clinical examination, diagnostic imaging and necropsy findings, and reported outcome in horses with CVM.
Design—Retrospective case-control study.
Animals—270 horses with CVM and 608 control horses admitted to 6 veterinary hospitals from 1992 through 2007.
Procedures—Medical records of participating hospitals were reviewed to identify horses with CVM (ie, case horses) and contemporaneous control (non-CVM-affected) horses that were admitted for treatment. Signalment was compared between case horses and control horses. Results of clinical examination, laboratory and diagnostic imaging findings, necropsy results, and outcome were assessed for horses with CVM.
Results—Case horses were younger (median age, 2 years) than were control horses (median age, 7 years). Thoroughbreds, warmbloods, and Tennessee Walking Horses were overrepresented in the CVM group. Gait asymmetry and cervical hyperesthesia were frequently detected in horses with CVM. Vertebral canal stenosis and articular process osteophytosis were commonly observed at necropsy; agreement between the results of radiographic or myelographic analysis and detection of lesions at necropsy was 65% to 71% and 67% to 78%, respectively. Of 263 horses with CVM for which outcome was recorded, 1 died and 172 (65.4%) were euthanatized.
Conclusions and Clinical Relevance—Odds of a diagnosis of CVM were greater in young horses and horses of specific breeds. Detection of gait asymmetry and cervical hyperesthesia were frequently reported in association with CVM. Accurate diagnosis of lesions associated with CVM by use of radiography and myelography can be challenging. (J Am Vet Med Assoc 2010;237:812-822)
Case Description—5 aged (≥ 17 years old) horses developed life-threatening Internal hemorrhage following IV administration of phenylephrine at 3 hospitals.
Clinical Findings—All 5 horses developed severe hemothorax, hemoabdomen, or both within minutes to hours following administration of phenylephrine.
Treatment and Outcome—Four of 5 horses died of hemorrhagic shock, and 1 horse survived with a blood transfusion. The exact source of hemorrhage was Identified In only 1 horse. Medical records of all horses with nephrosplenic entrapment of the large colon and treated with phenylephrine at the University of Florida Veterinary Medical Center between 2000 and 2008 (n = 74) were reviewed. Three of these 74 (4%) horses developed fatal hemorrhage (horses 1 through 3 of this report). The risk of developing phenylephrine-associated hemorrhage was 64 times as high (95% confidence interval, 3.7 to 1,116) in horses ≥ 15 years old than in horses < 15 years old.
Clinical Relevance—The potential risks versus benefits of phenylephrine administration should be evaluated carefully, especially In old horses. (J Am Vet Med Assoc 2010;237:830–834)
Objective—To determine whether plasma N-terminal proatrial natriuretic peptide (NT-proANP) concentration could predict the outcome (survival duration) of cats with cardiomyopathy (CM).
Animals—51 cats with CM (25 with and 26 without congestive heart failure [CHF]) and 17 healthy cats.
Procedures—Cats were thoroughly examined and assigned to 1 of 3 groups (control, CM with CHF, and CM alone). Plasma NT-proANP concentrations were measured by use of a human proANP(1-98) ELISA. Survival durations were compared between CM groups.
Results—Plasma NT-proANP concentrations differed significantly among the 3 groups, and survival durations differed significantly between the 2 CM groups. Median (range) NT-proANP concentration was 413 fmol/mL (52 to 940 fmol/mL) in the control group, 1,254 fmol/mL (167 to 2,818 fmol/mL) in the CM alone group, and 3,208 fmol/mL (1,189 to 15,462 fmol/mL) in the CM with CHF group. At a cutoff of 517 fmol/mL, NT-proANP concentration had a sensitivity of 90% and specificity of 82% for detecting CM. Multivariate analysis revealed that only the variable left atrium-to-aortic diameter ratio was a significant predictor of survival duration.
Conclusions and Clinical Relevance—Plasma NT-proANP concentration may have potential as a testing marker for distinguishing healthy cats from cats with CM. It may also be useful for distinguishing CM cats with CHF from those without CHF The value of NT-proANP concentration as a predictor of survival duration was not supported in this study and requires further evaluation. (J Am Vet Med Assoc 2010;237:665-672)
Objective—To examine acid-base and hormonal abnormalities in dogs with diabetes mellitus.
Animals—48 dogs with diabetes mellitus and 17 healthy dogs.
Procedures—Blood was collected and serum ketone, glucose, lactate, electrolytes, insulin, glucagon, cortisol, epinephrine, norepinephrine, nonesterified fatty acid, and triglyceride concentrations were measured. Indicators of acid-base status were calculated and compared between groups.
Results—Serum ketone and glucose concentrations were significantly higher in diabetic than in healthy dogs, but there was no difference in venous blood pH or base excess between groups. Anion gap and strong ion difference were significantly higher and strong ion gap and serum bicarbonate concentration were significantly lower in the diabetic dogs. There were significant linear relationships between measures of acid-base status and serum ketone concentration, but not between measures of acid-base status and serum lactate concentration. Serum insulin concentration did not differ significantly between groups, but diabetic dogs had a wider range of values. All diabetic dogs with a serum ketone concentration > 1,000 μmol/L had a serum insulin concentration < 5 μU/mL. There were strong relationships between serum ketone concentration and serum glucagon-insulin ratio, serum cortisol concentration, and plasma norepinephrine concentration. Serum β-hydroxybutyrate concentration, expressed as a percentage of serum ketone concentration, decreased as serum ketone concentration increased.
Conclusions and Clinical Relevance—Results suggested that ketosis in diabetic dogs was related to the glucagon-insulin ratio with only low concentrations of insulin required to prevent ketosis. Acidosis in ketotic dogs was attributable largely to high serum ketone concentrations.
Objective—To evaluate camelids with hypertriglyceridemia with regard to signalment, clinical features of disease, and response to treatment with insulin.
Design—Retrospective case series.
Animals—23 alpacas and 8 llamas with hypertriglyceridemia.
Procedures—For analysis of medical record data, 20 hypertriglyceridemic camelids with multiple recorded measurements of serum or plasma triglycerides concentration were classified as follows: those with an initial triglycerides concentration > 60 to ≥ 500 mg/dL that were or were not treated with insulin (HT-I and HT-N camelids, respectively) and those with an initial triglycerides concentration > 500 mg/dL that were treated with insulin (lipemic [LIP-I] camelids). Only 1 recorded triglycerides concentration was available for an additional 11 hypertriglyceridemic camelids; data from those records were included in the characterization of signalment and clinical features of disease.
Results—Compared with the general population of hospitalized camelids, hypertriglyceridemic camelids did not differ significantly with respect to age or sex. Of 22 female camelids, only 7 were lactating or pregnant. Serum or plasma triglycerides concentrations in HT-N and HT-I camelids did not differ significantly at admission, but triglycerides concentrations in HT-I camelids decreased significantly after insulin treatment. Posttreatment triglycerides concentrations in HT-I camelids were significantly lower than those in HT-N camelids. During the period of hospitalization, triglycerides concentrations in HT-N camelids increased, whereas those in LIP-I camelids decreased significantly.
Conclusions and Clinical Relevance—Results indicated that hypertriglyceridemia affects llamas and alpacas of all ages and both sexes. Insulin treatment may reduce serum or plasma triglycerides concentrations in camelids with hypertriglyceridemia.
Objective—To characterize clinical signs, clinicopathologic features, treatments, and survival in dogs with naturally acquired foodborne aflatoxicosis.
Design—Retrospective case series.
Animals—72 dogs that consumed aflatoxin-contaminated commercial dog food.
Procedures—Medical records of affected dogs were reviewed. Between December 2005 and March 2006, dogs were identified as having foodborne aflatoxin hepatotoxicosis on the basis of the history of consumption of contaminated food or characteristic histopathologic lesions (subject dog or a recently deceased dog in the same household or kennel). Recorded information included signalment, clinical features, clinicopathologic test results, treatments, and survival. Data were analyzed by survival status.
Results—Most dogs were of large breeds from breeding kennels. No significant differences were found in age or weight between 26 (36%) survivor dogs and 46 (64%) nonsurvivor dogs. Severity of clinical signs varied widely; 7 dogs died abruptly. In order of onset, clinical features included anorexia, lethargy, vomiting, jaundice, diarrhea (melena, hematochezia), abdominal effusion, peripheral edema, and terminal encephalopathy and hemorrhagic diathesis. Common clinicopathologic features included coagulopathic and electrolyte disturbances, hypoproteinemia, increased serum liver enzyme activities, hyperbilirubinemia, and hypocholesterolemia. Cytologic hepatocellular lipid vacuolation was confirmed in 11 dogs examined. In comparisons of clinicopathologic test results between survivor and nonsurvivor dogs, only granular cylindruria (7/21 dogs) consistently predicted death. Best early markers of aflatoxicosis were low plasma activities of anticoagulant proteins (protein C, antithrombin) and hypocholesterolemia. Despite aggressive treatment, many but not all severely affected dogs died.
Conclusions and Clinical Relevance—Serum liver enzyme activities and bilirubin concentration were unreliable early markers of aflatoxin hepatotoxicosis in dogs. Hypocholesterolemia and decreased plasma protein C and antithrombin activities may function as exposure biomarkers.
Objective—To describe a technique for abdominocentesis in camelids and report peritoneal fluid biochemical and cytologic findings from healthy llamas and alpacas.
Animals—17 adult llamas and 5 adult alpacas.
Procedures—Right paracostal abdominocentesis was performed. Peritoneal fluid was collected by gravity flow into tubes containing potassium-EDTA for cell count and cytologic evaluation and lithium heparin for biochemical analysis. Blood samples were collected via jugular venipuncture into heparinized tubes at the same time. Cytologic components were quantified. Fluid pH and concentrations of total carbon dioxide, sodium, potassium, chloride, lactate, and glucose were compared between peritoneal fluid and venous blood.
Results—All but 3 camelids had peritoneal fluid cell counts of < 3,000 nucleated cells/μL, with < 2,000 neutrophils/μL and < 1,040 large mononuclear cells/μL. All but 1 had peritoneal fluid protein concentrations of ≥ 2.5 g/dL. Peritoneal fluid of camelids generally contained slightly less glucose, lactate, and sodium and roughly equal concentrations of potassium and chloride as venous blood.
Conclusions and Clinical Relevance—Peritoneal fluid was collected safely from healthy camelids. Compared with blood, peritoneal fluid usually had a low cell count and protein concentration, but some individuals had higher values. Electrolyte concentrations resembled those found in blood. High cell counts and protein concentrations found in peritoneal fluid of some healthy camelids may overlap with values found in diseased camelids, complicating interpretation of peritoneal fluid values.
Objective—To evaluate the effects of twice-daily oral administration of a low-dose of trilostane treatment and assess the duration of effects after once-daily trilostane administration in dogs with naturally occurring hyperadrenocorticism (NOH).
Animals—28 dogs with NOH.
Procedures—22 dogs received 0.5 to 2.5 mg of trilostane/kg (0.23 to 1.14 mg/lb) orally every 12 hours initially. At intervals, dogs were reevaluated; owner assessment of treatment response was recorded. To assess drug effect duration, 16 of the 22 dogs and 6 additional dogs underwent 2 ACTH stimulation tests 3 to 4 hours and 8 to 9 hours after once-daily trilostane administration.
Results—After 1 to 2 weeks, mean trilostane dosage was 1.4 mg/kg (0.64 mg/lb) every 12 hours (n = 22 dogs; good response [resolution of signs], 8; poor response, 14). Four to 8 weeks later, mean dosage was 1.8 mg/kg (0.82 mg/lb) every 12 or 8 hours (n = 21 and 1 dogs, respectively; good response, 15; poor response, 5; 2 dogs were ill). Eight to 16 weeks after the second reevaluation, remaining dogs had good responses (mean dosages, 1.9 mg/kg [0.86 mg/lb], q 12 h [n = 13 dogs] and 1.3 mg/kg [0.59 mg/lb], q 8 h ). At 3 to 4 hours and 8 to 9 hours after once-daily dosing, mean post-ACTH stimulation serum cortisol concentrations were 2.60 and 8.09 μg/dL, respectively.
Conclusions and Clinical Relevance—In dogs with NOH, administration of trilostane at low doses every 12 hours was effective, although 2 dogs became ill during treatment. Drug effects diminished within 8 to 9 hours. Because of potential adverse effects, lower doses should be evaluated.