Prevalence of naturally occurring non-AB blood type incompatibilities in cats and influence of crossmatch on transfusion outcomes.

BACKGROUND: Recognition of the feline red blood cell (RBC) antigen Mik and the presence of naturally occurring anti-Mik antibodies resulting in acute hemolytic transfusion reactions prompted the recommendation to perform a crossmatch before a cat's first RBC transfusion, but this guideline has not yet become a standard practice. OBJECTIVE: To determine the prevalence of naturally occurring non-AB alloantibodies detectable by tube crossmatch, and to compare transfusion outcomes in cats with and without a crossmatch performed. ANIMALS: Three hundred cats that received an RBC transfusion, with or without a major crossmatch performed. METHODS: Retrospective study. RESULTS: Major crossmatch incompatibilities were documented in 23 of 154 transfusion-naive cats (14.9%) and in 15 of 55 previously transfused cats (27%; P = 0.042). Type-specific packed RBCs (pRBCs) were administered to 167 and 82 cats with and without a crossmatch, respectively. Median volume of pRBCs administered during the first transfusion was 5.3 mL/kg (range, 2.4-18 mL/kg). Median change in PCV scaled to dose of pRBCs was +0.8%/mL/kg; administration of crossmatch-compatible pRBCs was not associated with a greater increase in PCV. Febrile transfusion reactions occurred more often in cats that received non-crossmatched (10.1%) compared to crossmatched (2.5%) pRBCs (P = 0.022). Seventy-six percent of cats that received pRBC transfusions survived to hospital discharge. A crossmatch was not associated with improved survival to discharge or at 30 or 60 days posttransfusion. CONCLUSIONS AND CLINICAL IMPORTANCE: The prevalence of naturally occurring non-AB incompatibilities is sufficiently high to justify the recommendation to perform a crossmatch before all (including the first) RBC transfusions in cats.

What can we learn from osteoarthritis pain in companion animals?

The lack of successful translation of basic research discoveries into safe and effective treatments for chronic pain patients has led to increased scrutiny of the preclinical models used in pain research, particularly for osteoarthritis, where there is a significant disconnect between the animal models used to study the structural versus symptomatic aspects of the disease. Companion dogs offer a unique opportunity to assess osteoarthritis pain in a physiologically relevant 'model' of the disease. Approximately 20% of the canine pet population spontaneously develops osteoarthritis, translating to at least 15 million dogs in the United States alone. As in humans, pathogenesis of canine osteoarthritis involves changes in all tissues of the synovial joint including articular cartilage, subchondral bone, and periosteum. The dominant symptom of osteoarthritis for both humans and dogs is pain, and the current therapeutic goal for both species is management of that pain and associated loss of function. To capture clinically and translationally relevant pain severity and pain impact data in the companion canine osteoarthritis 'model', clinical metrology instruments have been validated. These instruments, which assess changes in spontaneous pain-related behaviours, over extended periods of time, in the dog's home environment, are used to evaluate the efficacy of novel interventions for chronic pain in canine osteoarthritis studies. There is evidence that these results in companion dogs can reliably predict efficacy in humans. Across many classes of compounds in which there have been studies in companion animal chronic pain conditions and the same conditions in humans, the analogous results have been seen. In addition, many of the drugs used to treat pain in people are successfully used off-label to treat pain in dogs as well. If preliminary indications of predictability hold true, companion dogs may be embraced as a missing link in the translation of osteoarthritis treatment from mice to men.

Preoperative thoracic radiographic findings in dogs presenting for gastric dilatation-volvulus (2000-2010): 101 cases.

OBJECTIVE: To identify the incidence of clinically significant findings on preoperative thoracic radiographs in dogs with gastric dilatation-volvulus (GDV) and to determine if those findings are associated with survival. DESIGN: Retrospective study from 2000 to 2010. SETTING: Urban university small animal teaching hospital. ANIMALS: One hundred and one dogs diagnosed with GDV that had thoracic radiographs obtained preoperatively, and medical records available with the following information available: signalment, time of presentation, respiratory status, plasma lactate, presence of cardiac arrhythmias, reason for thoracic radiographs, radiographic findings, and outcome. INTERVENTIONS: None. RESULTS: Findings on preoperative thoracic radiographs included small vena cava (40%), esophageal dilation (39%), microcardia (34%), aspiration pneumonia (14%), cardiomegaly (5%), pulmonary nodule (4%), pulmonary edema (2%), sternal lymphadenopathy (1%), and pulmonary bullae (1%). Eighty-four percent of dogs (85 out of 101) survived to discharge. Dogs without cardiomegaly on presenting thoracic radiographs had a 10.2 greater odds of surviving to discharge. CONCLUSIONS: The most common findings on preoperative thoracic radiographs include esophageal dilation, microcardia, and a small vena cava while the incidence of pulmonary nodules was low. A negative association between survival and presence of cardiomegaly on preoperative thoracic radiographs in dogs with GDV supports the need to obtain these images for prognostic information in spite of the emergency surgical nature of the GDV. The main limitations of this study include the possibilities of type I and type II errors, the retrospective nature of the study, and the lack of well-defined criteria for obtaining thoracic radiographs.

Measurement of resiniferatoxin in cerebrospinal fluid by high-performance liquid chromatography.

A sensitive and simple high-performance liquid chromatographic (HPLC) assay was developed for the quantification of resiniferatoxin (RTX) in canine cerebrospinal fluid (CSF). A reversed-phase C(18) column and acetonitrile in 0.02 M NaH(2)PO(4) as mobile phase provided satisfactory resolution for RTX analysis. Direct HPLC analysis of the CSF samples without sample extraction or preparation improves the accuracy and detection limits of this assay. This assay was applied to measure CSF RTX content to test this method for research and clinical applications related to studies examining its analgesia effects.