Clinical Signs, Computed Tomographic Imaging, and Management of Chronic Otitis Media/Interna in Dairy Calves

Abstract

A 3½-week-old Holstein heifer calf was presented to Cornell University Hospital for Animals (CUHA) with a 2-week history of intermittent fever, coughing, and decreased growth and a 1-week history of drooling and droopy ears. The calf had been treated with several antibiotics without marked improvement. On physical examination, the calf was depressed, underweight, bradycardic (heart rate 60 bpm) and febrile (103.4ЊF, 39.7ЊC). Clinical signs attributable to cranioventral pneumonia included bilateral mucopurulent nasal discharge, coughing, and abnormal bronchial tones. Intermittently, there were food particles in the nasal discharge, ptyalism, difficult prehension and mastication of food, and regurgitation of green material from both the nose and mouth. Neurologic examination revealed depression, bilateral facial nerve paresis (decreased lip, eyelid, and ear tone; absent palpebral or menace reflex), and bilateral vestibular disease (balance loss to either side, no head tilt, and loss of physiologic vestibular nystagmus). No abnormal nystagmus was observed, but the eyeballs did not show the physiologic vestibular eyedrop on head and neck extension. The gait was normal. The diagnosis of bilateral cranial nerve (CN) VII and VIII disease suggested bilateral otitis media/interna. Deep palpation of the base of the ears elicited a pain response and nonodorous otorrhea was present, indicating a component of otitis externa. Upper airway and esophageal endoscopy was consistent with dysphagia and disturbed esophageal motility and showed tracheal mucopus, nasopharyngeal collapse, dorsal displacement of the soft palate, and esophageal dilatation with few contractions. Thoracic radiography and transtracheal aspirate cytology (many degenerate neutrophils, few macrophages, large amounts of mucus, no bacteria) confirmed the presence of bronchopneumonia. The transtracheal aspirate yielded Arcanobacter pyogenes and Mycoplasma spp., but fluorescent antibody testing for common respiratory viruses was negative. CBC results were normal. Lumbosacral cerebrospinal fluid (CSF) had a slightly high nucleated cell count (9 nucleated cells/L, normal Ͻ5 cells/L; total protein concentration 17 mg/dL, normal Ͻ70 mg/dL). Lateral skull radiographs did not show abnormalities, but computed tomography (CT) imaging indicated that both tympanic bullae and the right petrous temporal bone were enlarged,

Computed Tomography of the Normal Bovine Tarsus

“…Another limitation of the use of CT in bovine practice is that the diameter of the gantry is not large enough to allow the passage of the whole body of the animal. However, it is possible to obtain a CT scan of the entire body (Lubbers et al., ) of calves and the head (Van Biervliet et al., ) and limbs (Raji et al., ) of cattle. Despite its cost, the use of CT should be considered for economically valuable cattle for achieving a comprehensive diagnosis and planning of a surgical intervention (Kofler et al., ).…”

“…Currently, CT enjoys a prominent role in the diagnosis and evaluation of many bovine diseases (Nuss et al., ). An ever‐increasing number of clinical reports involving CT assessment of bovine diseases are appearing in literature (Frame et al., ; Van Biervliet et al., ; El‐Khodery et al., ; Frederick et al., ; Becker et al., ; Lee et al., ). Because of the complexity of the bovine tarsus, a CT anatomy guide with standard reconstruction planes is necessary for accurate interpretation of CT images in patients.…”

Mycoplasma bovisInfections in Cattle

“…Imaging (radiography, computed tomography) has been used as an aid in the diagnosis of otitis media/interna in calves. 10,54 How Should Samples Be Collected and Handled?…”

“…1 In mycoplasma otitis media, the affected tympanic bullae contain suppurative to caseous exudate and have often undergone extensive osteolysis. 9,54 During field necropsy the ventral aspect of the bulla can be opened and swabbed or aspirated for culture. Joints with M. bovis arthritis contain nonodorous fibrinous to caseous exudate accompanied by fibrosis.…”

“…There is 1 report of successful surgical treatment of a calf with M. bovisassociated otitis media-interna in which a bilateral tympanic bulla osteotomy was performed. 54 Because improved efficacy is observed when treatment is initiated early in the course of experimental disease, early recognition and treatment of cases are likely to be When Might Metaphylactic Antimicrobials be Indicated for M. bovis-Associated Disease?…”