Ear Disease In Dogs Research Articles

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.

Changes in the ear canal microbiota of dogs with otitis externa.

Otitis externa (OE), one of the most common ear diseases in dogs, is caused by bacterial pathogens such as Staphylococcus sp. To understand the network of microbial communities in the canine ear canal affected with OE, we performed a cross-sectional study using next-generation sequencing. Ear swab samples were collected from 23 OE-affected and 10 healthy control dogs, and the 16S rRNA gene sequenced using Illumina MiSeq. The otic microbiota in the OE-affected dogs showed significantly decreased alpha diversity compared to controls. The community composition also differed in the affected group, with significantly higher relative abundance of the phylum Firmicutes and the genus Staphylococcus (P=0·01 and 0·04 respectively). Contrary to our expectations, the severity of the disease did not impact the otic microbiota in OE-affected dogs. The ear canal microbiota of OE-affected dogs is distinct from that of healthy dogs, irrespective of disease status. This study, one of the few detailed analyses of the otic microbiota, can provide practical information for the appropriate treatment of canine OE.

Prevalence of ear diseases in dogs – a retrospective 5-year clinical study

Prevalence of ear diseases in dogs – a retrospective 5-year clinical study

Management of Otitis in Rabbits

Diseases of the ear are common in pet rabbits. The basic anatomy of the “standard” rabbit is similar to the canine and feline ear; however, there are a few important differences. Otitis refers to inflammation of one or more structure of the ear and includes otitis externa (the ear canal), otitis media (tympanic membrane, bony acoustic duct, and tympanic cavity), and otitis interna (inner ear). Etiology and clinical presentations of the different classifications of otitis in rabbits are revised in this article. Available techniques for a thorough diagnostic work up and recommendations for a tailored medical treatment are presented from the available literature. Numerous surgical techniques have been described for management of ear disease in dogs, and many have been extrapolated for use in rabbits, occasionally without considering significant differences in anatomy between species, especially in the lop rabbit. The authors report both the advantages and disadvantages associated with the available surgical techniques that have been described to treat rabbit ear disease. Because of limited case numbers and follow-up data, retrospective information on long-term outcome for these procedures is not available.

Complication Rates After Bilateral versus Unilateral Total Ear Canal Ablation with Lateral Bulla Osteotomy for End-Stage Inflammatory Ear Disease in Dogs: 79 Ears.

To determine whether perioperative complication rates are different between unilateral (ULS) versus single-stage bilateral (BLSS) total ear canal ablation-lateral bulla osteotomy (TECA-LBO) surgeries. Retrospective case series. Fifity-seven dogs (79 ears) undergoing TECA-LBO at a single institution over 14 years. Medical records of dogs undergoing TECA-LBO for end-stage inflammatory non-neoplastic ear disease from March 1999 to September 2013 at the Colorado State University Veterinary Teaching Hospital were evaluated for intraoperative and early postoperative complications associated with the procedure. Inclusion criteria were clinical and/or histopathologic diagnosis of chronic otitis externa, surgical treatment by TECA-LBO, and a minimum of 2 week follow-up data. Twenty dogs (40 ears) underwent BLSS and 37 dogs (39 ears) had ULS. Complications were recorded for 29 of 40 ears (72.5%) in the BLSS group (40.0% facial nerve, 15.0% ocular, and 32.5% minor incisional complications) and 25 of 39 ears (64.1%) in the ULS group (33.3% facial nerve, 12.8% ocular, and 23.1% minor incisional complications). Dogs undergoing BLSS did not have a significantly higher total complication rate, or higher neurologic, ocular, or incisional complication rates, than the ULS procedure. No major anesthetic complications affecting outcome were recorded for either group. Anesthetic and early surgical complication rates after ULS and BLSS were not significantly different in our study. Offering single-stage bilateral TECA-LBO procedures for otherwise healthy dogs with end-stage inflammatory otitis externa is a viable treatment option without additional risk for complication.

First identification of methicillin-resistant Staphylococcus pseudintermedius strains among coagulase-positive staphylococci isolated from dogs with otitis externa in Trinidad, West Indies

BackgroundOtitis externa is a common inflammatory ear disease in dogs caused by a variety of pathogens, and coagulase-positive staphylococci are frequently isolated from such infections.ObjectiveTo identify antimicrobial susceptibility profiles and methicillin-resistant strains among coagulase-positive staphylococci isolated from otitis externa in dogs.MethodsA cross-sectional study was performed over 2 years on 114 client-owned dogs presented to the Veterinary Teaching Hospital with a primary complaint of ear infections. Swabs were obtained from both ears and cultured for staphylococci which were subsequently confirmed as coagulase-positive using rabbit plasma. Antimicrobial susceptibility assays were assessed on all isolates followed by subsequent genetic analysis for species identification and detection of the mecA gene.ResultsSixty-five coagulase-positive staphylococci were isolated from 114 client-owned dogs. The isolates exhibited resistance against neomycin (58.5%), streptomycin (49.2%), penicillin (49.2%), polymyxin B (44.6%), tetracycline (36.9%), sulphamethoxazole/trimethoprim (33.8%), kanamycin (33.8%), doxycycline (32.3%), norfloxacin (23.1%), amoxicillin/clavulanate (20%), ciprofloxacin (20%), enrofloxacin (18.5%), gentamicin (16.9%), and cephalothin (9.2%). Forty (61.5%) of the isolates were resistant to at least three or more antimicrobials and 10 were sensitive to all. Using a multiplex polymerase chain reaction assay based on species-specific regions of the thermonuclease (nuc) gene, 38/65 (58.5%) isolates were classified as Staphylococcus aureus, 23/65 (35.4%) as S. pseudintermedius, 2/65 (3.1%) as S. intermedius, and 2/65 (3.1%) as S. schleiferi. Analysis for the mecA gene revealed two positive isolates of S. pseudintermedius which were oxacillin-resistant, representing a first report of such organisms in the Caribbean.ConclusionDespite the relatively high prevalence of multidrug-resistant coagulase-positive staphylococci in Trinidad, these are largely susceptible to gentamicin consistent with use in clinical practice. The first detection of methicillin-resistant S. pseudintermedius (MRSP) in dogs is likely to have implications on the treatment options for otitis externa in dogs and potential public health significance.

Prevalence of ear disease in dogs undergoing multidetector thin-slice computed tomography of the head.

Previous reports describing the prevalence of ear diseases in dogs have primarily been based on dogs presenting with clinical signs of disease. The prevalence of subclinical ear disease remains unknown. The purpose of this cross-sectional retrospective study was to describe the prevalence of lesions consistent with middle and external ear disease in dogs presented for multidetector computed tomography (CT) of the head and/or cranial cervical spine at our hospital during the period of July 2011 and August 2013. For each included dog, data recorded were signalment, CT findings, diagnosis, and treatment. A total of 199 dogs met inclusion criteria. Nineteen dogs (9.5%) were referred for evaluation of suspected ear disease and 27 dogs (13.5%) had histories or physical examination findings consistent with otitis externa. A total of 163 dogs (81.9%) had CT lesions consistent with external ear disease (i.e. ear canal mineralization, external canal thickening, and/or narrowing of the external canal). Thirty-nine dogs (19.5%) had CT lesions consistent with middle ear disease (i.e. soft tissue attenuating/fluid material in the tympanic bullae, bulla wall thickening or lysis, and/or periosteal proliferation of the temporal bone). Findings from this study indicated that the prevalence of external and middle ear disease in dogs could be higher than that previously reported.

Avaliação ultrassonográfica do meato acústico em cães

O propósito deste trabalho foi determinar a viabilidade da ultrassonografia para avaliar o canal auditivo externo de cães, aferindo a espessura e arquitetura da parede do conduto auditivo e bula timpânica. Foram avaliados 10 cães da raça Retriever do Labrador não portadores de otite externa. O exame foi realizado com o aparelho de ultrassonografia bidimensional e transdutor linear de 14 MHz, com todos os animais sob efeito de anestesia geral. O exame foi efetivado antes e depois do conduto ser preenchido com solução salina, promovendo uma janela acústica anecóica. A artéria maxilar foi identificada com o Doppler colorido o que facilitou a localização da bula timpânica em todos os cães. A definição da imagem da parede proximal ao transdutor foi pior quando comparada à parede distal r em todos os animais, isto devido à proximidade da parede com a face de leitura do transdutor. Nos cães que apresentavam uma maior quantidade de cerúmen a superfície do epitélio estava com uma camada hiperecóica mais evidente. A membrana timpânica não foi identificada em nenhum animal. Conclui-se que ultrassonografia é viável e deve ser mais pesquisada na contribuição diagnóstica das doenças óticas em cães.

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.

Preventive Ear Care for Dogs and Cats

Prevention of ear disease in dogs and cats depends on early detection of factors that predispose these animals to otitis externa. This article reviews the conditions and diseases that place the dog and cat at risk for otitis externa. Routine care of the ears is discussed, and otoscopic examination and techniques for cleaning the external auditory canals are described. Avoidance of potentially harmful therapeutic procedures and irritating or ototoxic pharmacologic substances is emphasized.

Pityrosporum pachydermatis weidman of canine origin

Though asporogenous yeasts were numerically greater in otitic than in healthy material, their incidence in healthy and diseased external ears was very similar and it is unlikely that they are of importance as causal agents of ear disease in dogs. They were identified as Pityrosporum pachydermatis Weidman by the fact that they multiplied on a broad base, showed no fermentative ability and grew readily on various media without added oleic acid, olive oil or other fatty substances. During the reproductive cycle, individual oval-shaped cells were seen without polar buds or visible evidence of blastospore formation. All strains hydrolysed urea and grew well on egg media with or without added glycerol or an extract of Mycobacteriumphlei . They were mostly resistant to antibiotics but were sensitive to high dilutions of certain commercial antiseptics. A growth-promoting factor for P. pachydermatis was produced by some pathogenic and non-pathogenic strains of staphylococci.

Otitis Externa in the Dog*

Abstract— The findings of two recent surveys of external ear disease in dogs are summarized, with particular reference to the aetiology of the condition and the results obtained with some methods of treatment.The commonest predisposing factors to otitis were clinical skin disease and ectoparasitic infestation, in that order. The appearance of the discharge in affected ears appeared to be related to the tissue changes present and to the nature of the infectious agents.Antibiotic sensitivity tests were of value and most cases responded promptly to appropriate medical treatment. In the more chronic cases, which were usually associated with considerable changes of the epithelium, treatment was often prolonged and about one in ten showed no improvement.Where medical treatment failed, thorough cleaning of the ear, under general anesthesia, was of value.A surgical technique is described which has been used with success in a number of cases and which, in certain circumstances, appears to have some advantage over the methods described by Zepp and Singh and Rao.