Retrospective study of the presentation, diagnosis and management of 16 cats with otitis media not due to nasopharyngeal polyp

Video-Assisted Ventral Bulla Osteotomy to Remove a Bullet Foreign Body in a Cat

A 7 yr old castrated male domestic shorthair presented for assessment of a chronic left head tilt, losses of balance, and positional nystagmus. A computed tomographic scan of the head revealed several fragments of a metallic foreign body in the left tympanic cavity. The foreign material was removed under endoscopic assistance through a minimally invasive ventral bulla osteotomy. No complications were noted during the immediate postoperative period. Follow-up 5 mo after surgery revealed complete resolution of the neurological signs with no evidence of recurrence. Foreign bodies associated with middle ear infection have not been previously reported in the cat. They should now be included in the differential diagnosis of vestibular disease. Endoscopic-assisted foreign body removal in the middle ear seems to be a safe and efficient way to retrieve small foreign bodies in bullae in cats.

Imaging findings in otitis media and resulting secondary lesions in dogs and cats - an image essay

Over the past 2 decades, the increasing availability of computed tomography (CT) and magnetic resonance imaging (MRI) as well as the growing professional expertise have significantly improved the diagnostics of middle and inner ear diseases in dogs and cats. In answering some of the diagnostic questions, CT and MRT demonstrate equivalent performance. For most questions, however, there are differences in the diagnostic performance due to the physical imaging properties of the 2 modalities.CT is more sensitive in demonstrating involvement of the bulla wall and is more effective for detecting abnormal content within the tympanic bulla. In addition, with CT it is often easier to guide tissue samplings. On the other hand, structural changes of the soft tissues of the skull, head, meninges, brain, and nerves are not or only insufficiently detectable on CT images. MRI is clearly superior here. Therefore, MRI is essential for the characterization of materials inside the bulla cavity and for demonstrating the extent of any central spread of otitis media (OM).In this image essay, CT and MRI features of OM and resulting secondary lesions described in the literature are analyzed and summarized. Own image examples are used for illustration. Information on the etiology, pathogenesis, pathomorphology, and clinical signs important for understanding these changes are presented in concise descriptions.

Evaluation of endoscopic-assisted feline lateral bulla osteotomy: a cadaveric study

OBJECTIVES

The aims of the study were to investigate if feline middle ear anatomy can be visualized using endoscopy via a lateral bulla approach and to determine if scope-assistance increases rates of successful entry into the hypotympanum during feline total ear canal ablation and lateral bulla osteotomy (TECA-LBO).

METHODS

A total of 13 feline cadaver heads underwent CT to confirm the absence of pre-existing middle ear disease. For each head, an electronic coin toss was used to determine which ear would undergo endoscope-assisted TECA-LBO; a traditional TECA-LBO without the use of the scope was performed on the contralateral side. In endoscope-assisted procedures, a 1.9 mm scope was intermittently inserted into the tympanic bulla via a lateral bulla approach and used to identify middle ear structures, visualize the bony septum and confirm entry into the hypotympanum. After the bilateral TECA-LBO, the cadaver heads were imaged again and assessed for evidence of entry through the septum.

RESULTS

Soft tissue and osseus structures of the middle ear were readily visualized with a 1.9 mm scope. Success rates for entry into the hypotympanum were high between both endoscope-assisted and traditional procedures, with entry confirmed for 12/13 ears in each group.

CONCLUSIONS AND RELEVANCE

Endoscope assistance can facilitate the identification and examination of middle ear structures but does not appear to increase the success rate of entry into the hypotympanum during feline TECA-LBO, as entry through the bony septum was consistently accomplished even without scope-assisted visualization. Alternative benefits to scope assistance may exist, and future studies to elucidate its impact on rates of intraoperative trauma to middle ear structures are indicated.

A Pandora's box in feline medicine: presenting signs and surgical outcomes in 58 previously hoarded cats with chronic otitis media-interna

OBJECTIVES

The aim of the present study was to report clinical findings, surgical complications and outcomes for previously hoarded cats treated surgically for otitis media-interna (OMI) and to investigate the risk factors for complications and poor outcomes.

METHODS

A retrospective study was conducted of 58 cats from an institutional hoarding environment that underwent ventral bulla osteotomy (VBO).

RESULTS

Inappetence was uncommon at presentation (9/58, 16%) compared with pruritus/alopecia (50%), nasopharyngeal signs (45%), otitis externa (OE) (79%) and otitis interna (OI) (ataxia ± head tilt/head excursions) in 40%. Purulent aural discharge occurred in 36% and polyps in 26%. The tympanic bulla wall was moderately or severely thickened radiographically in 38/108 (35%) ears. Cultures were positive for Streptococcus equi subspecies zooepidemicus in 26/48 (54%) cats. Of the 58 cats, 40 (69%) had complications after the first VBO and 19/30 (63%) after the second. Of 101 complications, 56 (55%), from 27/88 (31%) surgeries, were considered serious, including life-threatening perioperative complications in seven, OI in eight, prolonged anorexia in six and worsening of pruritus/alopecia in nine cases. Three cats developed xerostomia (dry mouth) after the second VBO. Pruritus/alopecia, nasopharyngeal signs, OE and purulent aural discharge resolved in a statistically significant proportion of cats but persisted in some. Full resolution of OI was uncommon. OI preoperatively, and surgery performed by a generalist (vs specialist) surgeon, were risk factors for OE at recheck (OI: odds ratio [OR] 4.35; 95% confidence interval [CI] 1.21-15.70; P = 0.02; surgery: OR 3.64; 95% CI 1.03-12.87; P = 0.045). No other prognostic indicators were identified. No variables tested were significantly associated with risk of serious complications or euthanasia.

CONCLUSIONS AND RELEVANCE

Surgical management of chronic OMI was successful in most cases but was not benign and not always beneficial. The analysis was unable to identify clinically helpful outcome predictors. Optimal management of chronic feline OMI remains a challenge, particularly for animal shelters. Less invasive approaches and chronic medical management require further investigation.

Otitis media and interna with or without polyps in cats: association between meningeal enhancement on postcontrast MRI, cerebrospinal fluid abnormalities, and clinician treatment choice and outcome

OBJECTIVES

The aim of this study was to evaluate the association between meningeal enhancement (MgE) and cerebrospinal fluid (CSF) analysis results, their individual association with bacteriology results from affected ear samples and whether these test results influenced clinicians' therapeutic choice in cats with otitis media and interna (OMI).

METHODS

This was a multicentre retrospective study carried out over an 8-year period. Cats diagnosed with OMI, with or without a nasopharyngeal polyp, leading to peripheral vestibular signs were included. Only cats for which MRI with postcontrast T1-weighted sequences and CSF analyses available were included. Cats with intra-axial MRI lesions or empyema were excluded.

RESULTS

Fifty-eight cats met the inclusion criteria. MgE was reported in 26/58 cases, of which nine had an abnormal CSF result (increased total nucleated cell count [TNCC] or total protein); 32/58 cases had no MgE, of which 10 showed abnormal CSF results. There was no association between bacteriology results (external ear canal or bulla) and MgE or abnormal CSF results. CSF abnormalities were statistically significantly more common in acute cases (n = 16/37) than in chronic cases (n = 3/21; Fischer's test P = 0.04). Prednisolone was prescribed in 10/16 cases with increased TNCC. Among the 42 cases with normal TNCC, 15 received prednisolone and 13 received non-steroidal anti-inflammatory drugs. Various antimicrobial drugs were prescribed in 53/58 cats. Duration of antimicrobial treatment was similar, regardless of positive bacterial culture (5.58 vs 4.22 weeks), abnormal CSF (5.83 vs 4.76 weeks) or MgE (5.33 vs 4.90 weeks).

CONCLUSIONS AND RELEVANCE

No association was found between the CSF and MgE results. Furthermore, no association was found between MgE, CSF or bacteriology findings. In addition, abnormal CSF results might lead the clinician to treat with corticosteroids, but they did not have any impact on duration of antimicrobial treatment. CSF abnormalities were seen significantly less frequently in chronic cases. The outcome tended to be poorer when MgE was detected on MRI.

Transoral ventral tympanic bulla osteotomy in cats: 13 cases (2016-2019)

OBJECTIVE

To analyze the results of transoral ventral bulla osteotomy (TOVBO) in cats.

ANIMALS

13 client-owned cats treated by TOVBO between February 2016 and February 2019.

PROCEDURES

Medical records of cats with a diagnosis of middle ear disease (MED) that underwent TOVBO were reviewed. The procedure was similar to the one described for dogs. Short-term follow-up was obtained via clinical examination before discharge and at day 15 postoperatively. Long-term follow-up was performed via telephone interview.

RESULTS

13 cats (age range, 8 months to 12 years) underwent unilateral (n = 10) or bilateral (3) TOVBO (16) for the treatment of tympanic bulla (TB) infection (10), nasopharyngeal inflammatory polyps (5), or bullet retrieval from the TB (1). There were no intraoperative complications. One cat with a poor preoperative status died at postoperative day 3 from pneumonia. Eight cats experienced postoperative complications including head tilt (n = 2), Horner syndrome (3), loss of appetite (2), and temporary blindness (1). Collected samples confirmed the presence of nasopharyngeal inflammatory polyps (5), or otitis media (8). Six months after surgical intervention, 9 cats were free of MED signs.

CLINICAL RELEVANCE

This oral approach provided a good access to the TB in all cases. The complications observed after TOVBO were similar to those for VBO. In cats, TOVBO seems to be an acceptable and safe minimally invasive alternative to the other approaches of the TB to address MED.

Clinical reasoning in feline vestibular syndrome: which presenting features are the most important?

OBJECTIVES

The aim of this study was to evaluate whether clinical variables from the history, clinical presentation, and physical and neurological examinations of cats with vestibular syndrome were statistically predictive of the underlying diagnosis.

METHODS

In total, 174 cats presenting with vestibular syndrome between January 2010 and May 2019 were investigated. Univariate statistical analysis of clinical variables was performed and those statistically associated with a diagnosis were retained for multivariable binary logistic regression modelling.

RESULTS

The seven most prevalent diagnoses represented 95% of vestibular presentations, which included: otitis media/interna (n = 48), idiopathic vestibular syndrome (n = 39), intracranial neoplasia (n = 24), middle ear polyp (n = 17), feline infectious peritonitis (n = 13), thiamine deficiency (n = 13) and intracranial empyema (n = 11). Idiopathic vestibular syndrome was commonly associated with non-purebred cats and had 17.8 times the odds of an improving clinical progression (95% confidence interval [CI] 1.3-250.0; P = 0.03). Intracranial neoplasia was associated with older age and chronic onset of clinical signs, and was significantly more likely to have a central vestibular neuroanatomical localisation (95% CI 8.5-344,349,142.0; P = 0.015) with postural deficits on neurological examination. Thiamine deficiency was more common in female cats, with 52.6 times the odds of a waxing and waning clinical progression (95% CI 1.2-1000; P = 0.038) and 6.8 times the odds of presenting with bilateral vestibular signs (95% CI 1.0-45.7; P = 0.047) and wide excursions of the head (95% CI 1.0-45.7; P = 0.047). Middle ear polyps were associated with 8.8 times the odds of presenting with Horner syndrome (95% CI 1.5-50.0; P = 0.015).

CONCLUSIONS AND RELEVANCE

Although it may be difficult to identify the underlying diagnosis in cats with vestibular syndrome from the presenting features alone, there are instances in which discrete clinical features may help to guide clinical reasoning when evaluating cats with vestibular presentations.

Clinical Techniques: When and how to do a myringotomy - a practical guide

A myringotomy is a surgical incision made in the tympanic membrane (TM). This gives access to the middle ear for sampling, flushing and instilling topical therapy. It should be considered whenever the TM is intact and there is clinical evidence of otitis media, abnormal TMs and/or abnormal diagnostic imaging. Samples should be collected for cytological investigation and culture, and then the external ear should be cleaned and dried (if required). Myringotomies should be performed under general anaesthesia and, wherever possible, using a video otoscope; the enhanced view and instrument ports facilitate the technique and reduce the risk of complications. The myringotomy incision should be made in the caudoventral quadrant of the TM using an appropriately sized urinary catheter to collect samples and flush the middle ear cavity. A thorough understanding of the anatomy, technique and potential ototoxicity of topical therapy is needed to minimize the risk of neurological and other complications. The TM usually heals within 35 days if kept free of infection.