Surgical treatment of middle ear cholesteatoma using an oral approach in 2 dogs

Middle ear cholesteatoma is caused by the formation of epidermoid cysts that result in distention and enlargement of the tympanic bulla with subsequent destruction of surrounding tissues. We report treatment of middle ear cholesteatoma in 2 dogs, via an oral surgical approach. Abnormal tympanic bulla contents and the wall compressing the pharynx were successfully removed in both cases. Computed tomography imaging, surgical findings, and histopathology results were consistent with middle ear cholesteatoma in both cases. The outcomes in both cases suggest that an oral surgical approach may be an alternative treatment for middle ear cholesteatoma in dogs.Key clinical message:Despite the limited number of cases described herein, our report indicates that the direct oral approach for canine cholesteatoma may be and alternative approach.     

Middle ear disease associated with congenital palatine defects in seven dogs and one cat

Medical records of eight dogs and one cat with congenital palatine defects were reviewed retrospectively. Five of the dogs had nasal discharge and seven had radiographic signs of middle ear disease, but no clinical signs of ear disease were identified in any of the dogs, nor were any reported by their owners during a one- to five-year follow-up period. One dog had an ipsilateral impairment of hearing detected by brainstem auditory evoked responses. The cat had clinical and radiographic signs of middle ear disease. These findings suggest that, as in humans, congenital palatine defects in dogs and cats may predispose to middle ear disease. Any associated deafness could cause problems for working dogs.     

MRI findings of a middle ear cholesteatoma in a dog

This article describes the MRI features of a middle ear cholesteatoma in an 8 yr old flat-coated retriever. Physical examination revealed pain on opening the jaw, and otoscopic examination showed tympanic membrane rupture associated with hyperplastic tissue at the entrance of the middle ear. Standard MRI sequences allowed for the identification of a severely expanded bulla containing material that was isointense to brain tissue on T1-weighted images and of mixed intensity on T2-weighted and fluid-attenuated inversion recovery sequences. No postcontrast enhancement of the content was present, but the lining of the bulla was partially enhanced. The images allowed evaluation of the surgical margins and the secondary changes due to the expansion of the mass. Surgery was performed and histopathology confirmed the presumptive diagnosis of cholesteatoma. In the present case, MRI appeared to serve as a good alternative to computed tomography for the diagnosis of cholesteatoma.     

Bilateral ear canal neoplasia in three dogs

Bilateral ear canal infections are common in dogs. Ear canal neoplasia is usually associated with unilateral problems, and is uncommon in dogs. To the best of the author's knowledge, bilateral aural neoplasia has not been reported in dogs, and only four case reports were found in the human literature. This report presents three dogs that had bilateral tumours in their ear canals. They were presented with bilateral otitis externa. All three dogs exhibited tissue proliferation of both ear canals that did not respond to glucocorticoids. Treatment consisted of total ear canal ablation, and tissues were submitted for histopathological evaluation. Case # 1 (a 10-year-old, male cocker spaniel) was diagnosed as ceruminious gland carcinoma. Cases # 2 and 3 were diagnosed as squamous cell carcinoma. Case # 1 was diagnosed 4 years earlier as having keratinization disorder, which was causing its chronic ear problems. Case # 2 (a 5-year-old, female French bulldog) was diagnosed 4 years earlier as having atopic dermatitis, which did not respond to hyposensitization, and only partially responded to glucocorticoids therapy. Case # 3 (a 9-year-old, male German shepherd) was diagnosed by the referring veterinarian as having unilateral ear canal proliferation 2 months prior to presentation. However, otoscopic examination showed bilateral proliferation that obstructed both canals. In summary, bilateral ear canal neoplasia should be considered in cases of nonresponsive, proliferative aural pathology.     

Clinical results of lateral ear resection in dogs

Twenty-six dogs had lateral ear resection performed for the treatment of chronic otitis externa. After a mean follow-up period of 4.5 years, 17 of the 26 dogs were available for physical examination. The remaining 9 dogs died prior to this review; their owners were surveyed by questionnaire. In the examined group, the resolution of clinical signs was good in 41% of the dogs, improved in 12%, and poor in 47%. A good result was defined as the elimination of clinical signs, with minimal or no care required from the owner. An improved status was assigned to dogs that experienced occasional recurrence of signs requiring professional attention. A poor result was defined as no improvement.     

Partial foot amputation in 11 dogs

Eleven dogs with malignant tumors of the digits and feet were treated with partial foot amputation. Partial foot amputation involved amputation of one or both central weight-bearing digits. Lameness occurred in all dogs but resolved in eight dogs at a median of 37 days postoperatively. In the remaining three dogs, lameness improved but did not resolve. Tumor control was excellent, with no evidence of local recurrence in 10 dogs. One dog underwent limb amputation. Based on these results, partial foot amputation may be recommended in the management of malignant tumors of the canine foot in which more than one digit must be amputated to achieve adequate surgical margins.     

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.     

Inflammatory polyps of the middle ear in 5 dogs

OBJECTIVE: To describe inflammatory polyps of the middle ear in 5 dogs. STUDY DESIGN: Case series. ANIMALS: Five dogs with ear disease. METHODS: Medical records (1995-2001) were reviewed to identify dogs with inflammatory polyps of the middle ear. Signalment, clinical signs, ancillary diagnostic procedures, treatment, postoperative complications, and outcome were recorded. Owners and referring veterinarians were contacted to document outcome. RESULTS: Dogs with inflammatory polyps of the middle ear were male and aged 4 to 13 years. Two dogs had bilateral polyps, whereas 3 had unilateral polyps. The most common clinical presentation was otitis externa and media, with radiographic evidence of otitis media. Polyps were treated by ventral bulla osteotomy (VBO) in 1 dog and total ear canal ablation with lateral bulla osteotomy (TECA-LBO) in 4 dogs. Polyps consisted of a fibrovascular stroma infiltrated with neutrophils, macrophages, lymphocytes, and plasma cells. The overlying epithelium was frequently ulcerated. Immediate postoperative complications included a seroma after VBO (1 dog) and transient unilateral facial nerve paralysis after bilateral TECA-LBO (1 dog). No recurrence occurred within 9 to 69 months. CONCLUSIONS: Unilateral or bilateral, inflammatory polyps can occur in the middle ear of dogs in association with otitis externa and media. No recurrence occurred after surgical removal of the polyps. CLINICAL RELEVANCE: Inflammatory polyps of the middle ear in dogs can be a cause of otitis externa/media. Surgical removal of aural polyps has a good prognosis.     

Neoplasia involving the middle ear cavity of dogs

Eleven cases of neoplasia which involved the middle ear cavity of dogs are recorded. Eight of the tumours originated in the external ear canal and comprised four adnexal tumours, one squamous papilloma and three adenocarcinomas of the ceruminous glands. Papillary adenomas were recognised within the middle ear cavity of two dogs. In one animal the precise origin of an anaplastic carcinoma involving the middle ear could not be determined. Only five of the tumours were amendable to surgical excision and four dogs survived for more than eight months after surgery.     

Methicillin-resistant Staphylococcus aureus infections in 11 dogs

Methicillin-resistant Staphylococcus aureus infection was identified in 11 dogs. The infection was associated with surgical treatment especially orthopaedic surgery. Infection after traumatic wounding, and recurrent pyoderma was also seen. Oral antibiotic treatment improved or resolved the infection in nine of the 11 dogs, although the methicillin-resistant isolates were susceptible to relatively few antibiotics.     

Bacteriology of the horizontal ear canal of dogs

Of 57 dogs included in a survey of the bacteriology of the horizontal ear canal, 31 showed clinical signs consistent with ear irritation. Twenty-six dogs were presented for other reasons and were asymptomatic for ear irritation. All dogs sampled were anaesthetized and sterile moistened swabs used to sample the horizontal ear canal. Swabs were introduced through a sterilized (121°C for 15 min) polypropylene otoscope cone and care was taken to prevent contamination of the cone with material from elsewhere in the ear canal. Swabs were processed within 20 min of sampling and cultures were incubated aerobically and anaerobically. Swabs from the ears of asymptomatic dogs were mixed in broth prior to plating to ensure optimal elution of small numbers of organisms from the swabs. Very small numbers of bacteria and yeasts were isolated from asymptomatic dogs while Pseudomonas spp. and Proteus spp. were frequent isolates from symptomatic dogs with chronic irritation. The significance of these findings is discussed in relation to the sampling and culturing techniques used in this and other surveys.     

Subtotal ear canal ablation in 18 dogs and one cat with minimal distal ear canal pathology

A modified technique for performing total ear canal ablations is described. This technique requires less dissection than the standard technique and maintains a portion of the distal vertical ear canal. Subtotal ear canal ablations were performed in 18 dogs and one cat for the treatment of otitis externa or masses of the horizontal ear canal. Animals with otitis externa had minimal involvement of the distal ear canal. Dermatological problems associated with the remaining ear canal and pinnae occurred in eight animals and resolved with medical management. Normal ear carriage was maintained in all animals with erect ears. Further investigation is required before the procedure can be recommended as a treatment for otitis externa not caused by masses or anatomical abnormalities of the horizontal ear canal in dogs with pendulous ears.     

Molecular characterization of Prototheca in 11 symptomatic dogs

Protothecosis is an uncommon disease caused by algae of the genus Prototheca. In dogs, the infection is usually first localized to the colon but has the propensity to later disseminate hematogenously to many other organs, with marked tropism for the eyes and central nervous system. Diagnosis is established by culture and/or evidence of Prototheca organisms in cytologic or histologic preparations. Species characterization, however, requires molecular investigations. Our laboratory set up a real-time PCR targeting portion D1/D2 of the 28S rRNA for identification of Prototheca species from both positive cultures (of rectal swabs and urine) and formalin-fixed, paraffin-embedded tissue. Prototheca bovis, P. ciferrii, and P. wickerhamii were characterized in 11 dogs with systemic or cutaneous protothecosis. Prototheca identifications were phylogenetically consistent with the new taxonomy proposed for this genus based on the mitochondrial cytochrome b gene. As a pilot study, we screened feces and rectal scrapes from 200 asymptomatic dogs, using 2 cohorts of stray and owned animals, to determine the prevalence of intestinal carriage of Prototheca spp. The Prototheca-negative results from both cohorts of healthy dogs suggest that predisposing factors related to the host probably contribute more to the acquisition of clinical disease than exposure to contaminated environments.     

Soft palate hypoplasia and concurrent middle ear pathology in six dogs

This retrospective clinical study describes six consecutive cases of bilateral hypoplasia/malformation of the soft palate in dogs in which associated middle ear disease was investigated and the palatine defects were surgical repaired. Radiographic abnormalities of the tympanic bullae were seen in both ears of all six dogs (12 of 12). Negative tympanocentesis findings were recorded in 11 of 12 ears. A purulent otitis media was confirmed in one ear of one dog, and loss of hearing was also demonstrated in this ear on brainstem auditory evoked response hearing assessment. There was no evidence of hearing loss on brainstem auditory evoked response in any of the remaining ears. Surgical repair of the soft palate defect was undertaken in all six dogs. Long-term assessment of the clinical outcome was considered excellent in five dogs and reasonable in one dog (mean 18 months, range seven to 27 months). It would appear that surgical intervention for the treatment of bilateral palatine malformation/hypoplasia may be associated with a better prognosis than reported previously. The lack of middle ear effusion and associated hearing impairment suggests that the underlying aetiology of middle ear pathology in dogs suffering from congenital palatine defects may be different from that observed in human beings. The true nature of the radiographic bullae changes seen in dogs with soft palate defects remains unclear.     

The pathology of the external ear canal in dogs and cats

A survey of factors which predispose the canine ear to otitis externa is presented. In resected ear specimens of 106 dogs, otitis externa without tumour was found on 58 occasions. In 46 dogs tumours were diagnosed in 15 cases with an otitis externa. In two dogs an inflammatory polyp was found. In the resected ear specimens of 48 cats, otitis externa was diagnosed 27 times, in 6 cases combined with an inflammatory polyp. In 21 cases neoplasia was present. The otitis externa was mainly a chronic proliferative inflammation characterised by hyperkeratinization, hyperplasia of the sebaceous and ceruminous glands, fibrosis and infiltration with plasma cells, lymphocytes and macrophages, often containing ceroid pigment.