Immunoglobulin M-capture enzyme-linked immunosorbent assay testing of cerebrospinal fluid and serum from horses exposed to west nile virus by vaccination or natural infection

The West Nile (WN) virus, present in the United States since 1999, is a cause of encephalomyelitis in birds, alligators, humans, and horses. No data exist regarding detection of anti-WN virus immunoglobins in equine cerebrospinal fluid (CSF). The aims of this study were to evaluate the blood-brain barrier (BBB) in WN virus-infected (WNE) horses, to compare diagnostic testing in serum and CSF, and to describe the immunoglobulin M (IgM) response in serum and CSF of vaccinated horses. CSF was collected from the lumbosacral (LS) space (n = 13) or the allanto-occipital (AO) space (n = 14) of WNE horses. The albumin quotient (AQ) and IgG index were calculated, and the IgM-capture-enzyme-linked immunosorbent assay (MAC-ELISA) was used to detect anti-WN virus IgM in serum and CSF. CSF collected from the LS site had a higher (P < .02) IgG index compared to the AO site (0.34 +/- 0.04 versus 0.22 +/- 0.04 [mean +/- SE], respectively). The mean AQ, irrespective of collection site, did not exceed reference values. There was 100% agreement between CSF and serum testing for IgM by MAC-ELISA testing. However, the positive to negative antigen ratios were higher (P < .001) in CSF (34.5) versus serum (8.5), indicating lower nonspecific reactivity in CSF samples. Horses vaccinated against WN virus did not develop an IgM response at 1:400 mg/dL in serum; however, a few horses developed a weak IgM response in serum but not in CSF. In conclusion, MAC-ELISA testing of serum and CSF were equivocal. Also, examination of CSF data from WNE horses suggests a normal BBB integrity and increased intrathecal production of antibodies.     

Red maple (Acer rubrum) leaf toxicosis in horses: a retrospective study of 32 cases

BACKGROUND: Ingestion of wilted red maple leaves by horses can result in severe hemolytic anemia and methemoglobinemia. Little is known about what factors influence the outcome of red maple leaf toxicosis in horses. HYPOTHESIS: Our hypothesis was that physical examination findings, clinicopathologic variables or therapeutic modalities may predict outcome in horses with red maple leaf toxicity. ANIMALS: Horses with red maple leaf toxicosis presented to referral hospitals in the southeast region of the United States. METHODS: A multi-institutional retrospective study was designed to identify factors that predict mortality in horses with red maple toxicosis. RESULTS: Thirty-two horses with red maple toxicosis were identified, 19 of which died. Twenty-nine horses presented with anemia and 24 had clinicopathologic evidence of systemic inflammation. Renal insufficiency was identified in 12/30 (41%) horses. Laminitis (9/28) and colic (13/30) also were identified in horses with red maple toxicosis, but development of these 2 conditions did not have a negative effect on short-term survival. Horses with red maple toxicosis that survived to discharge were likely to have developed pyrexia during hospitalization (P = .030). Horses that were treated with a corticosteroid had a significantly increased likelihood of death (P = .045). There was no significant relationship between initial serum hemoglobin concentration, methemoglobin concentration, or percentage methemoglobin and mortality in this horse series. CONCLUSIONS AND CLINICAL IMPORTANCE: This study suggests that information obtained on initial examination cannot be used to accurately predict survival in horses with red maple toxicosis, but horses that receive corticosteroids are unlikely to survive.     

Pancreatitis in cats: diagnosis and management of a challenging disease

Feline pancreatitis can be a very difficult disease to diagnose and often requires a combination of clinical suspicion, appropriate physical examination findings, elevations in serum feline pancreatic lipase immunoreactivity, and changes on abdominal ultrasonography consistent with pancreatic disease. The diagnostic difficulties encountered are related to a lack of specific and readily attributable clinical signs in cats. The sensitivity and specificity of the diagnosis of pancreatitis are highest when a combination of tests is utilized; but even when such tests are employed, the diagnosis is still problematic, especially in cats with chronic pancreatitis. Therapy is symptomatic and focuses on maintaining fluid volume, controlling pain and vomiting, preventing infection, and adjusting to changes in the cat's condition as they occur.     

Spiders associated with the meadow and tree canopies of orchards respond differently to habitat fragmentation

The response of animal communities to habitat quality and fragmentation may vary depending on microhabitat associations of species. For example, sensitivity of species to woody habitat fragmentation should increase with their degree of association with woody plants. We investigated effects of local and landscape factors on spider communities in different microhabitats within Swiss apple orchards. We expected a stronger negative effect of woody habitat fragmentation on spiders inhabiting tree canopies compared to spiders living in the meadow. The 30 orchards that we sampled varied in woody habitat amount and isolation at landscape and patch scales. Local factors included management intensity and plant diversity. Spiders associated with meadow were affected by plant diversity, but not by fragmentation. In contrast, spiders associated with canopies responded to isolation from other woody habitats. Surprisingly, we found both positive and negative effects of habitat isolation on local abundance. This indicates that differences in dispersal and/or biotic interactions shape the specific response to habitat isolation. The relative importance of local and landscape factors was in accordance with the microhabitat of the spiders. Thus, considering microhabitat associations can be important for identifying processes that would be overlooked if sampling were pooled for the whole habitat.     

Effects of continuous rate intravenous infusion of butorphanol on physiologic and outcome variables in horses after celiotomy

A randomized, controlled, blinded clinical trial was performed to determine whether butorphanol administered by continuous rate infusion (CRI) for 24 hours after abdominal surgery would decrease pain and surgical stress responses and improve recovery in horses. Thirty-one horses undergoing exploratory celiotomy for abdominal pain were randomly assigned to receive butorphanol CRI (13 microg/kg/h for 24 hours after surgery; treatment) or isotonic saline (control). All horses received flunixin meglumine (1.1 mg/kg IV q12h). There were no significant differences between treatment and control horses in preoperative or operative variables. Treatment horses had significantly lower plasma cortisol concentration compared with control horses at 2, 8, 12, 24, 36, and 48 hours after surgery. Mean weight loss while hospitalized was significantly less for treatment horses than control horses, whether expressed as total decrease in body weight (13.9+/-3.4 and 27.9+/-4.5 kg, respectively) or as a percentage decrease in body weight (2.6+/-0.7 and 6.3+/-1.1%, respectively). Treatment horses were significantly delayed in time to first passage of feces (median times of 15 and 4 hours, respectively). Treatment horses had significantly improved behavior scores during the first 24 hours after surgery, consistent with the conclusion that they experienced less pain during that time. Butorphanol CRI during the immediate postoperative period significantly decreased plasma cortisol concentrations and improved recovery characteristics in horses undergoing abdominal surgery.     

Nonsecretory Multiple Myeloma in a Dog: Immunohistologic and Ultrastructural Observations

A 12-year-old, female spayed Chihuahua was diagnosed with nonsecretory multiple myeloma on the basis of multiple osteolytic lesions, histological evidence of plasma cell infiltrate on a bone biopsy, and absence of a monoclonal protein on serum and urine electrophoresis. A 6-week course of prednisone therapy resulted in no clinical improvement and the dog was euthanized 2 weeks after presentation because of progressive neurological impairment. Bone marrow specimens were processed and stained for ultrastructural and immunohistologic evaluation. Staining with antisera to immunoglobulin (Ig) G, IgM, and IgA was negative. Tumor cells in both the pelvic and rib masses displayed prominent reactivity with an antibody specific for a canine β1 integrin similar to VLA-4; however, the tumor cells failed to stain with antibodies known to react predominantly with antigens on B-lymphocytes (major histocompatibility complex class II, CD45RA, and CD21) or T-lymphocytes (Thy-1). The tumor cells also failed to stain with an antibody specific for the β-subunit (CD18) of the leukocyte integrins (CD11/CD18). Ultrastructural studies performed on bone marrow specimens revealed a pleomorphic population of plasma cells with moderate amounts of rough endoplasmic reticulum, erythrophagocytosis, and lack of crystalline inclusions.     

Occupational per-patient radiation dose from a conservative protocol for veterinary (18) F-fluorodeoxyglucose positron emission tomography

The occupational external radiation dose to human medical personnel from positron emission tomography (PET) radiopharmaceuticals has been documented, but to date no corresponding veterinary staff dose data are available. Electronic personal dosimeters (EPDs) were used in this study to measure the per-patient external radiation doses to veterinary staff using a PET/CT (PET combined with computed tomography) protocol in which the patient radiopharmaceutical dose was injected after anesthetic induction. Radiation doses were recorded for the nuclear medicine technologists, the on-duty anesthesiology technologist, and an occasional observer from 19 veterinary (18) F-fluorodeoxyglucose PET/CT studies. Patient mass range was 2.8 to 61.0 kg (22.3 kg mean) and injected activity averaged 6 MBq kg(-1) . The dose range received by nuclear medicine technologists per procedure was 0-30 μSv (9.1 μSv mean), by anesthetists 1-22 μSv (8.2 μSv mean), and by the observer 0-2 μSv (0.5 μSv mean). In both feline and canine studies, placement of the EPD on staff was a significant predictor of radiation dose. Additional significant predictors of staff radiation dose from canine studies included job position and injected activity. The per-patient occupational radiation doses to veterinary PET/CT technologists were slightly greater than those reported for human nuclear medicine PET/CT technologists, but were comparable to estimated radiation doses for nurses caring for nonambulatory human PET/CT patients. Efforts toward maintaining staff radiation doses as low as reasonably achievable (ALARA) will be important as veterinary PET/CT caseload increases.