CHANGES IN ECHOCARDIOGRAPHIC VARIABLES OF LEFT VENTRICULAR SIZE AND FUNCTION IN A MODEL OF CANINE NORMOVOLEMIC ANEMIA

The objective of this study was to document changes in echocardiographic variables of left ventricular size and function noninvasively during acute normovolemic anemia. This model was developed as a pilot study with the purpose of providing baseline information to investigate the pathophysiology, and more specifically the effect on the heart, of canine babesiosis-induced anemia. The study group comprised of 11 mature healthy Beagle dogs that weighed between 9 and 15 kg. Severe normovolemic anemia was induced over a 3-4-day period by serial bleeding while maintaining normovolemia by autotransfusing plasma and infusing crystalloids. The dogs were then allowed to recover. Preanemic (mean Hct 46.7%, standard deviation [SD] 2.4%) echocardiographic variables of left ventricular performance (Fractional shortening, ejection fraction, end-systolic and end-diastolic ventricular volumes, cardiac index, and heart rate) were compared with those in the severely (mean Hct 15.3%, SD 1.1%), moderately (Hct mean 24.7%, SD 1.5%), and mildly (mean Hct 33.5%, SD 2.5%) anemic states, and between the anemic states. With the exception of end diastolic volume, there was a statistically significant (P < 0.05) increase in all variables in the severely anemic state vs. the preanemic and the mild and moderate anemic states. In concordance with previous invasive models, a hyperdynamic state of the left ventricle develops in response to experimentally induced acute canine normovolemic anemia in the conscious dog. Echocardiography has promise as a noninvasive technique of evaluating the cardiac changes in dogs having canine babesiosis.     

The incidence of thoracic trauma in dogs with skeletal injury

One hundred dogs with skeletal injury were evaluated for co-existing thoracic abnormalities. Parameters used to assess thoracic trauma were physical examination, thoracic radiographs, electrocardiograms and arterial blood gas PaO₂. Thoracic abnormalities were found in 57 per cent of the dogs. Within this group, 77 per cent had abnormal thoracic radiographs, 44 per cent had abnormal low PaO₂, and 30 per cent had cardiac arrhythmias. No clinical signs suggestive of thoracic injury were found on physical examination in 79 per cent of the dogs with thoracic lesions.     

COMPARISON OF FLAT-PANEL DIGITAL TO CONVENTIONAL FILM-SCREEN RADIOGRAPHY IN DETECTION OF EXPERIMENTALLY CREATED LESIONS OF THE EQUINE THIRD METACARPAL BONE

Radiographic diagnosis of equine bone disease using digital radiography is prevalent in veterinary practice. However, the diagnostic quality of digital vs. conventional radiography has not been compared systematically. We hypothesized that digital radiography would be superior to film-screen radiography for detection of subtle lesions of the equine third metacarpal bone. Twenty-four third metacarpal bones were collected from horses euthanized for reasons other than orthopedic disease. Bones were dissected free of soft tissue and computed tomography was performed to ensure that no osseous abnormalities were present. Subtle osseous lesions were produced in the dorsal cortex of the third metacarpal bones, and the bones were radiographed in a soft tissue phantom using indirect digital and conventional radiography at standard exposures. Digital radiographs were printed onto film. Three Diplomates of the American College of Veterinary Radiology evaluated the radiographs for the presence or absence of a lesion. Receiver operator characteristic curves were constructed, and the area under these curves were compared to assess the ability of the digital and film-screen radiographic systems to detect lesions. The area under the ROC curves for film-screen and digital radiography were 0.87 and 0.90, respectively ( P =0.59). We concluded that the digital radiographic system was comparable to the film-screen system for detection of subtle lesions of the equine third metacarpal bone.     

COMPARATIVE PERFORMANCE OF RADIOGRAPHY AND COMPUTED TOMOGRAPHY IN THE DIAGNOSIS OF MIDDLE EAR DISEASE IN 31 DOGS

The purpose of this study was to compare computed tomography (CT) and radiography for diagnosing the presence and severity of middle ear disease in dogs with a history of chronic otitis externa. Thirty-one dogs undergoing a total ear canal ablation and bulla osteotomy were studied. Three normal dogs served as controls. All dogs were examined using radiography and CT. Three radiologists independently evaluated imaging studies in random order. A visual analog scale method was used for scoring certainty and severity of middle ear disease. Surgical findings were recorded intra-operatively. Bulla lining samples were submitted for histopathologic evaluation and scored by a single pathologist who also used a visual analog scale system. Findings from both imaging modalities agreed more closely with surgical findings than with histopathologic findings. With either surgical or histopathologic findings as the gold standard, CT was more sensitive than and as specific as radiographs for predicting presence and severity of middle ear disease. Observer performance with CT was more consistent than the performance with radiographs in the detection of changes that occur with middle ear disease. Both radiography and CT were more accurate for predicting the severity of the disease than its presence. Findings indicate that CT is more accurate and reliable than radiography in diagnosing middle ear disease for dogs having concurrent otitis externa, but only when severity of disease is moderate or high. With low severity of disease, diagnostic certainty for both modalities becomes more variable.     

IMPROVED DETECTION OF METASTATIC HEPATIC HEMANGIOSARCOMA NODULES WITH CONTRAST ULTRASOUND IN THREE DOGS

Three dogs with a splenic hemangiosarcoma were imaged with conventional gray-scale ultrasound and no lesions were identified in the liver. After administration of intravenous ultrasound contrast medium (Definity) small, poorly enhanced, hypoechoic nodules were identified in the liver in each dog. The spleen and liver lesions were identified at surgery and the dogs underwent splenectomy and nodule biopsy. All lesions were identified histologically as hemangiosarcoma. These preliminary results suggest that contrast ultrasound may result in improved detectability of metastatic hepatic hemangiosarcoma.     

Surgical Correction of Congenital Bilateral Choanal Atresia in a Foal

Congenital bilateral choanal atresia was corrected surgically in a neonatal foal. Presenting clinical signs included complete obstruction of the upper airway, which had been relieved by tracheotomy. The diagnosis was confirmed by endoscopic examination and contrast radiography. Bilateral nasal flaps were used to gain access to the caudal nasal cavity, allowing removal of obstructive tissue and restoration of normal respiration. Malocclusion developed secondary to surgical intervention and resultant damage to suture lines of developing flat bones of the skull. Nine months postoperatively, the asynchronous growth of the mandible and maxilla had not resulted in difficulty during mastication. Respiration, although audible during periods of exercise, was acceptable to the owners.     

Implantation of an Uncemented Total Hip Prosthesis Technique and Initial Results of 100 Arthroplasties

A porous-coated modular total hip system was developed for uncemented implantation in dogs. The operative technique was developed in cadaver bones and live animals. One hundred uncemented total hip arthroplasties were performed in 92 dogs. Results were successful in 98% of the joints during follow-ups of 3 months or more. Complications included three luxations of the prosthetic joint, two fissure fractures of the femoral cortex, and one complete displacement of the acetabular component from its bony bed. Four complications were resolved successfully.     

Importance of the Straits of Florida spawning ground to Atlantic sailfish (Istiophorus platypterus) and blue marlin (Makaira nigricans)

Much of the uncertainty in managing highly migratory pelagic species results from the scarcity of fisheries-independent data relevant to determining long-term trends in abundance, migratory movements, and the relative importance of different spawning grounds. To address these issues, we used an ichthyoplankton-based method to quantify the overall level of spawning of sailfish ( Istiophorus platypterus ) and blue marlin ( Makaira nigricans ) in the Straits of Florida (SF). We estimated that during the 2 years (2003–2004) of the study, 4.60 × 10¹¹ sailfish eggs and 4.49 × 10¹¹ blue marlin eggs were produced on an annual basis in this region. These egg production values, when combined with estimates of annual fecundity for each species and the most recent stock assessment estimate of total biomass, indicate that about 2.1% of Western Atlantic sailfish spawning and 1.6% of Atlantic-wide blue marlin spawning occurs in the SF. Additionally, pop-up satellite tags deployed on sailfish at the start of the spawning season revealed their short residency times in the SF, suggesting that a large (≈13%) transient portion of the sailfish population is responsible for the SF egg production. Overall, this study provides a critically needed fisheries-independent method of quantifying spatial and temporal trends in the abundance of highly migratory species. The application of this methodology in the SF indicated that above-average levels of sailfish and blue marlin spawning occur in this area and, possibly more importantly, that the SF is a migratory bottleneck for these species.     

Metastasis of osteosarcoma to the bladder in a Finnish harrier: a case report

Osteosarcoma has not been previously reported to have metastasized to the urinary bladder in the dog. Here such a case is reported; the diagnosis was based on clinical, radiological, scintigraphic and histological verification of the primary and metastatic tumours.