Evaluation of plasma canine C-reactive protein concentrations in dogs with otitis media, healthy dogs and dogs with chronic otitis externa

BACKGROUND

Otitis is characterised by inflammation of one or more of the structures of the ear. At present, to confirm or exclude otitis media (OM), it is most often necessary to perform a computed tomography (CT) scan or magnetic resonance imaging. Inflammation is an immune defence response found in many conditions that can be detected and tracked by measuring biological markers of inflammation as the Canine C-reactive protein (CRP).

OBJECTIVES

The objective of this study was to determine whether CRP measurement is useful as an adjunctive diagnostic tool in dogs with otitis and whether elevated concentrations correlated with disease severity/presence of OM.

ANIMALS

Twenty-four client-owned dogs were recruited over 1 year.

MATERIALS AND METHODS

The dogs were divided into three groups: chronic or recurrent otitis externa (CO), otitis media (OM) and H (healthy). The dogs with otitis underwent a CT scan of the head, measurement of the plasma CRP concentration and evaluation of a 0-3 Otitis Index Score 3 (OTIS3 score).

RESULTS

No dog (0%) in group H had an increased CRP value, compared to 20% in the CO group (one of five dogs) and 23% in the OM group (3 of 13 dogs). Plasma CRP concentrations show a statistically significant positive relationship with the OTIS3 score (p = 0.04).

CONCLUSION AND CLINICAL RELEVANCE

Plasma CRP concentration is not reliable as a discriminatory tool in cases of otitis, although there is a trend for elevation in cases with more severe disease. However, a larger study may provide a statistically more reliable correlation between the severity of OM and CRP concentrations.

Microbiological study of the auditory canal in dairy calves with otitis media

Otitis media (OM) in calves, is caused by different bacteria. OM treatment requires identification of etiological agents and antibiotic sensitivity testing. The gold standard method of bacteriological study of OM is tympanocentesis, but using this technique in farm condition would be difficult. As a hypothesis, it is possible that bacteriologic examining the auditory canal can help to accelerate the bacteriological investigation of OM. This study was conducted with the aim of comparing the microbiota of the auditory canal in healthy calves and calves with OM. The present research which was a case-control study, mainly compared control group (18 swab samples from healthy and non-infected ear) with two case groups (20 swab samples from the non-affected ear and 32 swab samples from the affected ear in unilateral OM, 11 swab samples from both affected ears in bilateral OM). The results of bacteriological investigations showed three categories of bacteria including: pathogens (Staphylococcus chromogenes, Corynebacterium pilosum, Corynebacterium ovis, Pseudomonas aeruginosa, Pasteurella multocida, Proteus vulgaris, Trueperella pyogenes, Klebsiella, Escherichia coli, Mycoplasma bovis), opportunists (Staphylococcus intermedius, Bacillus licheniformis) and commensals (Staphylococcus epidermidis, Corynebacterium bovis, Corynebacterium renale, Bacillus subtilis, Bacillus cereus). Based on the antibiotic sensitivity test of the isolates, enrofloxacin, florfenicol, and gentamicin were the chosen antibiotics for treatment. All affected animals were treated based on bacteriological results and antibiotic sensitivity tests. All treated animals were fully cured. Based on the results, it seems that in calves with OM, examining the microbiota of the auditory canal can be further studied as an alternative to tympanocentesis in farm conditions.

Interleukin-31 in serum and cerebrospinal fluid of dogs with syringomyelia

BACKGROUND

Syringomyelia is a spinal cord cavity containing cerebrospinal fluid (CSF)-like fluid. If syringomyelia asymmetrically involves the dorsal horn grey matter of the spinal cord, affected dogs show increased signs of dysesthesia and neuropathic pain, like increased itching behaviour. In the dorsal horn, amongst others, receptors for Interleukin-31 (IL-31) can be found. IL-31 is one of the main cytokines involved in the pathogenesis of pruritus in atopic dermatitis in different species. This study investigates suspected elevated levels of IL-31 in serum and CSF of dogs showing signs of pain or increased itching behaviour related to syringomyelia. The IL-31 were measured in archived samples (52 serum and 35 CSF samples) of dogs with syringomyelia (n = 48), atopic dermatitis (n = 3) and of healthy control dogs (n = 11) using a competitive canine IL-31 ELISA.

RESULTS

Mean serum IL-31 level in dogs with syringomyelia was 150.1 pg/ml (n = 39), in dogs with atopic dermatitis 228.3 pg/ml (n = 3) and in healthy dogs 80.7 pg/ml (n = 10). Mean CSF IL-31 value was 146.3 pg/ml (n = 27) in dogs with syringomyelia and 186.2 pg/ml (n = 8) in healthy dogs. Individual patients with syringomyelia (especially dogs with otitis media or otitis media and interna or intervertebral disc herniation) showed high IL-31 levels in serum and CSF samples, but the difference was not statistically significant. IL-31 serum and CSF levels did not differ significantly in dogs with syringomyelia with or without itching behaviour and with or without signs of pain.

CONCLUSION

Based on this study, increased IL-31 levels seem not to be correlated with itching behaviour or signs of pain in dogs with syringomyelia, but might be caused by other underlying diseases.

Lateral ear canal resection and bulla osteotomy with marsupialization to treat otitis media in rabbits: forty-eight procedures

OBJECTIVE

Describe lateral ear canal resection and bulla osteotomy with marsupialization (LECARBOM) in rabbits with otitis media (OM), and report outcomes, complications, bacteria cultured from middle ears, and their antimicrobial susceptibility testing (AST) results.

STUDY DESIGN

Retrospective clinical case series; single referral hospital.

ANIMALS

Forty-two rabbits with naturally occurring OM.

METHODS

Medical records (2011-2021) of rabbits with CT-confirmed OM undergoing surgery were reviewed for outcomes, complications, bacteria cultured from middle ears, and AST.

RESULTS

Surgery was performed on 48 ears, and outcomes determined 21 days postoperatively. All rabbits survived the procedure. Otitis externa resolved in all lop-eared rabbits. Of 29 ears with OM-associated head tilt, eight (28%) resolved, nine (31%) improved, seven (24%) remained unchanged and five (17%) worsened. Outcome was not associated with head tilt duration nor OM severity. Postoperative complications occurred in 12 (25%) cases, seven of which had wound margin dehiscence that healed by 21 days. The most frequent bacteria isolated were Pasteurella multocida (16%), Bordetella bronchiseptica (14%) and Staphylococcus aureus (14%). Bacteria were sensitive to azithromycin, marbofloxacin or enrofloxacin and resistant to penicillin.

CONCLUSION

LECARBOM is a well-tolerated surgical procedure to treat OM. It also improved or stabilized 83% of cases with head tilt and resolved all cases with otitis externa.

CLINICAL SIGNIFICANCE

LECARBOM with administration of an AST-sensitive antibiotic, or azithromycin when no AST is performed, should be effective in rabbits with OM. Postsurgically, it resolves or alleviates most secondary conditions such as otitis externa, head tilt and facial nerve paralysis.

Refractory otitis media and otitis externa in a koala (Phascolarctos cinereus) treated with total ear canal ablation and lateral bulla osteotomy

BACKGROUND

To the authors' knowledge, this is the first report fully describing the surgical and medical management of otitis media and otitis externa in the koala (Phascolarctos cinereus) treated by total ear canal ablation and lateral bulla osteotomy.

CASE REPORT

An adult male koala captured as part of a monitoring project in South East Queensland was diagnosed with chlamydial cystitis. Purulent discharge from the right ear was also observed; diagnostic imaging was consistent with otitis media and otitis externa. Yokenella regensburgei was repeatedly cultured from the site. Clinical signs resolved with topical antibiotic therapy; however, recrudesced following cessation of antibiotics. A total ear canal ablation and lateral bulla osteotomy was performed, followed by an extended period of systemic antibiotic therapy. Mild facial nerve paresis was observed for 4 weeks postoperatively and resolved spontaneously. The koala remained clinically healthy for the 6 months it was monitored following release.

CONCLUSION

Total ear canal ablation combined with lateral bulla osteotomy appears to be an appropriate surgical intervention for otitis media combined with otitis externa refractory to medical management in the koala. Transient postoperative facial nerve paresis is a possible complication, as documented in other species. To the authors' knowledge this is the first case of Yokenella regensburgei infection outside of humans and American alligators (Alligator mississippiensis); the clinical significance of this pathogen in the koala remains unknown.

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.

Clinical signs, MRI findings and outcome in dogs with peripheral vestibular disease: a retrospective study

BACKGROUND

Vestibular dysfunction is relatively common in dogs, with a prevalence of 0.08% reported in primary veterinary care in the UK. There are several studies investigating how to differentiate between peripheral and central vestibular disease but only limited information regarding the possible underlying causes for peripheral vestibular dysfunction in dogs. This study therefore aimed to describe the clinical signs, magnetic resonance imaging findings (MRI), underlying causes and outcome in a large population of dogs diagnosed with peripheral vestibular disease.

RESULTS

One hundred eighty-eight patients were included in the study with a median age of 6.9 years (range 3 months to 14.6 years). Neurological abnormalities included head tilt (n = 185), ataxia (n = 123), facial paralysis (n = 103), nystagmus (n = 97), positional strabismus (n = 93) and Horner syndrome (n = 7). The most prevalent diagnosis was idiopathic vestibular disease (n = 128), followed by otitis media and/or interna (n = 49), hypothyroidism (n = 7), suspected congenital vestibular disease (n = 2), neoplasia (n = 1) and cholesteatoma (n = 1). Long-term follow-up revealed persistence of head tilt (n = 50), facial paresis (n = 41) and ataxia (n = 6) in some cases. Recurrence of clinical signs was observed in 26 dogs. Increasing age was associated with a mild increased chance of diagnosis of idiopathic vestibular syndrome rather than otitis media and/or interna (P = 0.022, OR = 0.866; CI 0.765-0.980). History of previous vestibular episodes (P = 0.017, OR = 3.533; CI 1.251-9.981) was associated with an increased likelihood of resolution of the clinical signs whilst contrast enhancement of cranial nerves VII and/or VIII on MRI (P = 0.018, OR = 0.432; CI 0.251-0.868) was associated with a decreased chance of resolution of the clinical signs.

CONCLUSIONS

Idiopathic vestibular disease is the most common cause of peripheral vestibular dysfunction in dogs and it is associated with advanced age. Incomplete recovery from peripheral vestibular disease is common, especially in dogs presenting with cranial nerve enhancement on MRI but less so if there is previous history of vestibular episodes.

Otitis in a cat associated with Corynebacterium provencense

BACKGROUND

The role of corynebacteria in canine and feline otitis has not been investigated in detail; however, members of this genus are increasingly recognized as pathogens of otitis in both human and veterinary medicine.

CASE PRESENTATION

Here we report the first case of feline otitis associated with the recently described species Corynebacterium provencense. A seven-month old cat presented with a head tilt and ataxia was diagnosed with peripheral vestibular syndrome associated with an otitis media/interna. This took place 6 weeks after resection of a polyp, having initially shown a full recovery with topical ofloxacin and glucocorticoid treatment. Bacteriology of an ear swab yielded a pure culture of corynebacteria, which could not be identified at the species level using routine methods. However, the 16S rRNA gene sequence was 100% identical to the recently published novel corynebacterium species, Corynebacterium provencense. Whole genome sequencing of the cat isolate and calculation of average nucleotide identity (99.1%) confirmed this finding. The cat isolate was found to contain additional presumptive iron acquisition genes that are likely to encode virulence factors. Furthermore, the strain tested resistant to clindamycin, penicillin and ciprofloxacin. The cat was subsequently treated with chloramphenicol, which lead to clinical improvement.

CONCLUSION

Corynebacteria from otitis cases are not routinely identified at the species level and not tested for antimicrobial susceptibility in veterinary laboratories, as they are not considered major pathogens. This may lead to underreporting of this genus or animals being treated with inappropriate antimicrobials since corynebacteria are often resistant to multiple drugs.

Comparison between cerebrospinal fluid and serum lactate concentrations in neurologic dogs with and without structural intracranial disease

The objectives of this study were to investigate the relationship between cerebrospinal fluid lactate and serum concentrations in dogs with clinical signs of central nervous system disease and to establish if cerebrospinal fluid lactate (CSF) concentrations are higher in dogs with structural intracranial disease (Group Pos-MRI) compared to dogs that have clinical signs of intracranial disease but no structural brain disease (Group Neg-MRI) based on magnetic resonance imaging (MRI) findings. Using a prospective study canine blood and cerebrospinal fluid were collected in 24 dogs with neurological signs after undergoing brain MRI. Dogs were divided in 2 groups. No significant difference between serum lactate (1.57 ± 0.9 mmol/L) and CSF lactate concentration (1.34 ± 0.3 mmol/L) was detected. There was a direct correlation between CSF and serum lactate concentration (R = 0.731; P = 0.01). No significant difference was found in CSF lactate concentration between the 2 groups of dogs (P = 0.13).

Severe upper airway obstruction following bilateral ventral bulla osteotomy in a cat

A cat that underwent bilateral ventral bulla osteotomy (VBO) for treatment of otitis media and otitis interna secondary to bilateral inflammatory polyps, developed upper airway obstruction (UAO) soon after tracheal extubation. The cat was re-intubated but the UAO did not resolve at the next extubation. Eventually, tracheostomy was performed. Upper airway obstruction is a potential postoperative complication of bilateral VBO in cats.

Cardiac arrest in an American Cocker Spaniel during a deep ear flush procedure

CASE DESCRIPTION A 14-year-old spayed female American Cocker Spaniel with bilateral otitis media and no evidence of cardiovascular instability was anesthetized to allow performance of a deep ear flush. CLINICAL FINDINGS Otoscopic examination of the left ear revealed evidence of chronic inflammation; the ear was flushed with sterile saline (0.9% NaCl) solution. Examination of the right ear revealed more severe chronic inflammation than in the left ear, including a ruptured tympanum (timing of rupture unknown). The right ear was flushed with sterile saline solution, and several drops of otic medication were instilled. During infusion of saline solution, the ECG revealed a rapid decrease in heart rate until no more electrical activity was noted. Pulse also ceased to be detectable via pulse oximetry and femoral artery palpation. TREATMENT AND OUTCOME Isoflurane was discontinued immediately after recognition of cardiac arrest. Shortly after, atropine (0.04 mg/kg [0.02 mg/lb]) and epinephrine (0.3 mg/kg [0.14 mg/lb]) were administered IV, chest compressions and ventilation were performed for 2 to 3 minutes, and 3 boluses (each 5 mL/kg) of lactated Ringer solution were administered IV. The dog was extubated 8 minutes after anesthesia was discontinued, and its recovery was monitored for the next 5 hours. No further incidents of cardiac arrest occurred after recovery from anesthesia. CLINICAL RELEVANCE This case represented a rarely documented potential complication associated with otic manipulation in a dog: cardiac arrest secondary to stimulation of the auricular branch of the vagus nerve. Veterinarians should be prepared for and warn clients of this possibility prior to otic flushing.

Cholesterol Granuloma Associated with Otitis Media and Destruction of the Tympanic Bulla in a Dog

An 8-year-old, male neutered Irish Setter was presented with a 2-week history of pain upon opening the mouth and chronic otitis externa. Computed tomography examination revealed destruction of the left tympanic bulla with a soft-tissue density within the remains of the tympanic cavity. Cytology of aspirates collected from tissue adjacent to the tympanic bulla revealed suppurative inflammation and bacteria. A ventral bulla osteotomy was performed. Histopathology of granulation tissue within the remains of the tympanic cavity was diagnostic of cholesterol granuloma.

Surgical Management of Ear Diseases in Rabbits

Otitis externa and media are frequently diagnosed disorders in rabbits and are particularly common in lop-eared breeds because of the specific anatomy of the ear canal. Medical management for otitis externa and media often provides only a temporary improvement in clinical signs. Surgery by means of partial or total ear canal ablation (PECA or TECA) combined with lateral bulla osteotomy (LBO) represents a feasible approach that is well tolerated and provides a good clinical outcome. Short-term complications associated with PECA/TECA-LBO include facial nerve paralysis and vestibular disease.

Cholesterol granuloma associated with otitis media and leptomeningitis in a cat due to a Streptococcus canis infection

Cholesterol granuloma in the middle ear is a pathological condition often associated with otitis media in humans. Cholesterol granulomas in cats are rarely described. To our knowledge, this is the first report of middle ear cholesterol granuloma in a cat, associated with otitis media and leptomeningitis due to a Streptococcus canis septicemia.

A retrospective study of 29 cases of otitis media/interna in dairy calves

Epidemiological data, clinical findings, laboratory data, medical imaging, and outcomes were reviewed in 29 dairy calves with otitis media/interna. Age at admission ranged from 1 to 24 wk. The majority of calves were referred during winter. Clinical signs included drooping ear, ptosis, head tilt, abnormal nystagmus, strabismus, dysphagia, regurgitation, stiff neck, opisthotonos, facial hyperesthesia, and purulent aural discharge. Intranasal endoscopic examination of 5 animals revealed nasopharyngeal collapse in 4. Cerebrospinal fluid (CSF) was abnormal in all of 7 cases. Mycoplasma bovis was cultured from all but 1 case with external ear or tympanic bullae samples (n = 12), and Mycoplasma arginini was cultured from the remaining ear sample. Radiographs of the tympanic bullae were performed in 24 calves, tomodensitometry (CT) in 3 calves and ultrasound in 4 calves. According to medical imaging techniques or necropsy, 69% of the cases were classified as chronic. Mean duration of treatment was 23.3 d. The rate of clinical recovery was 75%. Epidemiological data, clinical findings, laboratory data, medical imaging, and outcomes were reviewed in 29 dairy calves with otitis media/interna. Age at admission ranged from 1 to 24 wk. The majority of calves were referred during winter. Clinical signs included drooping ear, ptosis, head tilt, abnormal nystagmus, strabismus, dysphagia, regurgitation, stiff neck, opisthotonos, facial hyperesthesia, and purulent aural discharge. Intranasal endoscopic examination of 5 animals revealed nasopharyngeal collapse in 4. Cerebrospinal fluid (CSF) was abnormal in all of 7 cases. Mycoplasma bovis was cultured from all but 1 case with external ear or tympanic bullae samples (n = 12), and Mycoplasma arginini was cultured from the remaining ear sample. Radiographs of the tympanic bullae were performed in 24 calves, tomodensitometry (CT) in 3 calves and ultrasound in 4 calves. According to medical imaging techniques or necropsy, 69% of the cases were classified as chronic. Mean duration of treatment was 23.3 d. The rate of clinical recovery was 75%.

Ultrasound evaluation of tympanic bulla in calves

An ultrasonographic approach for the tympanic bulla in calves is described. Ultrasound evaluation was performed through a lateral approach on 7 fetuses, 2 newborn calves, and 4 living calves of various ages. The probe was positioned caudal to the vertical mandibular ramus, ventral to the base of the ear. Three different positions of the probe were used. The tympanic bulla and adjacent structures were successfully identified and their ultrasonographic appearance described. Fluid within the tympanic bulla was visualized in 12 bullae in the cadavers and in 6 bullae in live calves. Ultrasound imaging has been shown to be useful but its diagnostic value remains to be studied in clinical cases of otitis media in calves.

Mycotic otitis media in a harbour porpoise (Phocoena phocoena)

A 9-year-old by-caught harbour porpoise (Phocoena phocoena) was subject to routine post-mortem examination. Major findings included parasitic infection (Stenurus minor) of the left middle ear and severe mycotic infection of the right middle ear. The morphological appearance of the causative organism was consistent with Aspergillus fumigatus. These pathological findings were likely to have impaired echolocation in this animal and this may have contributed to the by-catch. The ears of marine mammals should be examined routinely during post-mortem investigations.

[Clinical application of computed tomography in cattle]

Computed tomography involves the use of x-rays to produce cross-sectional images of body regions. It provides non-overlapping, two-dimensional images of all desired planes as well as three-dimensional reconstruction of regions of interest. There are few reports on the clinical use of computed tomography in farm animals. Its use in cattle is limited by high cost, the application of off-label drugs and the need for general anaesthesia. In cattle computed tomography is indicated primarily for diseases of the head, e.g. dental diseases and otitis media, and neurological disorders. Less often it is used for diseases of the vertebrae and limbs. In valuable cattle, the results of computed tomography can be an important part of preoperative planning or be used to avoid unnecessary surgery when the prognosis is poor.

Mapping the anatomy of respiratory syncytial virus infection of the upper airways in chinchillas (Chinchilla lanigera)

Although most viral infections of the upper respiratory tract can predispose to bacterial otitis media, human respiratory syncytial virus (HRSV) is the predominant viral copathogen of this highly prevalent pediatric polymicrobial disease. Rigorous study of the specific mechanisms by which HRSV predisposes to otitis media has been hindered by lack of a relevant animal model. We recently reported that the chinchilla, the preferred rodent host for studying otitis media, is semipermissive for upper-airway HRSV infection. In the current study, we defined the anatomy and kinetics of HRSV infection and spread in the upper airway of chinchilla hosts. Chinchillas were challenged intranasally with a fluorescent-protein-expressing HRSV. Upper-airway tissues were recovered at multiple time points after viral challenge and examined by confocal microscopy and immunohistochemistry. HRSV replication was observed from the rostral- to caudalmost regions of the nasal cavity as well as throughout the Eustachian tube in a time-dependent manner. Although fluorescence was not observed and virus was not detected in nasopharyngeal lavage fluids 14 d after infection, the latest time point examined in this study, occasional clusters of immunopositive cells were present, suggesting that the nasal cavity may serve as a reservoir for HRSV. These data provide important new information concerning the time course of HRSV infection of the uppermost airway and suggest that chinchillas may be useful for modeling the HRSV-induced changes that predispose to secondary bacterial infection.

Mycoplasma bovis and otitis in dairy calves in the United Kingdom

Signs of severe otitis media in 20% of dairy calves on one farm were associated with Mycoplasma bovis infection, based on isolation from the external ear canal and nares. Affected calves seroconverted to M. bovis and no other significant bacteria were isolated. Infection was considered likely to have originated from cows in the milking herd based on evidence of seroconversion and detection of infection in a milk sample. M. bovis infection should be considered when investigating otitis problems in calves.

Anatomy and ultrasonographic appearance of the tympanic bulla and associated structures in the rabbit

Otitis media is a relatively common condition in the rabbit although it can be difficult to evaluate clinically. Diagnostic imaging of the rabbit has traditionally involved radiography and there are few reports regarding the use of ultrasound. The aim of this study was to determine if the tympanic bulla (TB) and associated structures could be evaluated in the rabbit using currently available ultrasound equipment. The normal anatomy of the region was established using gross dissection and emascerated specimens and compared with the dog and cat. Ten New Zealand white rabbit cadavers were examined using two ultrasound machines and four transducers from a variety of locations. A 12 MHz linear transducer was found to be most appropriate. From a lateral approach the external ear canal could be visualized to the level of the external acoustic meatus while the TB itself could only be visualized from a ventral approach. The jugular and mastoid processes in the rabbit are very prominent and interfered with imaging of the TB from all approaches. Water-soluble lubricant introduced into the TB could be identified through the ventral bone wall of the TB and allowed the lumen and far wall to be visualised. Further work is required to determine whether ultrasound examination of the TB can be performed in live rabbits and to evaluate its benefits in the evaluation of clinical cases of otitis media.

Pseudomonas aeruginosa otitis media and interna in a chinchilla ranch

Pseudomonas aeruginosa has been associated with conjunctivitis, enteritis, pneumonia, septicemia, sudden death, and abortion in chinchillas. This case report describes an unusual clinical presentation and diagnosis of P. aeruginosa otitis media and interna with neurologic manifestations. To our knowledge, this clinical presentation has not been reported previously in chinchillas.

Clinical signs, magnetic resonance imaging features, and outcome after surgical and medical treatment of otogenic intracranial infection in 11 cats and 4 dogs

Brainstem dysfunction resulting from central extension of infection is a life-threatening complication of otitis media/interna (OMI) that has been described infrequently in dogs and cats. We review the clinical signs of disease, diagnostic findings, and results of surgical and medical treatments of brainstem disease attributable to otogenic intracranial infection in cats and dogs. Eleven cats and 4 dogs were examined because of acute, subacute, or chronic clinical signs of brain disease including central vestibular signs, altered mentation, abnormal posture/gait, cranial nerve deficits, and seizures. Results of a minimal database (CBC, serum biochemical panel, urinalysis, thoracic radiographs, and abdominal ultrasonographic images or radiographs) were within reference intervals in all animals. Magnetic resonance (MR) images of the head were acquired for all animals, and cisternal cerebrospinal fluid (CSF) from 9 of 11 cats and 3 of 4 dogs was examined. Surgical exploration and ventral bulla osteotomy were done for 12 of 15 animals, followed by 1-3 months of antibiotic therapy; the remaining animals were euthanized before treatment. In all animals, MR imaging was effective in characterizing the location and extent of the pathologic changes intracranially as well as within middle/inner ear structures. Results of CSF analysis were characteristic of bacterial infection in most of the animals with acute or subacute disease. Since long-term outcome in all treated animals was very good to excellent, it was concluded that dogs and cats with intracranial disease secondary to extension of otitis media/interna have a good-to-excellent prognosis when the condition was diagnosed and was treated by surgical exploration and appropriate antibiotic therapy.

In vitro activity of an ear rinse containing tromethamine, EDTA, and benzyl alcohol on bacterial pathogens from dogs with otitis

OBJECTIVE

To evaluate the in vitro activity of an ear rinse (ER) containing tromethamine, EDTA, and benzyl alcohol on bacterial pathogens from dogs with otitis.

SAMPLE POPULATION

Organisms were collected from ear swab specimens from the external and middle ear and included Staphylococcus spp (n = 11; Staphylococcus intermedius [7] and Staphylococcus spp [4]), Pseudomonas aeruginosa (5), Proteus spp (5), beta-hemolytic streptococcus (11), and 1 control strain of each organism.

PROCEDURES

3 test solutions were evaluated including EDTA, tromethamine, and benzyl alcohol (ER); EDTA and tromethamine (ER without benzyl alcohol [ER - BA]); and purified water. Ten-milliliter aliquots of each test solution were transferred into 36 tubes and inoculated with one of the organisms. Samples were retrieved from each tube at 0, 15, 30, 45, and 60 minutes, transferred to Petri dishes, mixed with soybean-casein digest agar, and incubated. After incubation, plates were examined for growth, and the number of colonies was expressed as CFU per milliliter.

RESULTS

ER significantly decreased bacterial growth in vitro of P aeruginosa and beta-hemolytic streptococcal organisms within 15 minutes, Proteus spp within 30 minutes, and Staphylococcus spp within 60 minutes. Comparatively, the presence of benzyl alcohol in ER significantly decreased bacterial growth of beta-hemolytic streptococcus and Proteus spp.

CONCLUSIONS AND CLINICAL RELEVANCE

On the basis of results of this study, future studies should be performed to evaluate the in vivo efficacy of ER alone as a treatment for otic infections caused by beta-hemolytic streptococcus, P aeruginosa, and Proteus spp and of ER combined with an antimicrobial agent for otic infections caused by Staphylococcus spp.

Evaluation of otoscope cone cleaning and disinfection procedures commonly used in veterinary medical practices: a pilot study

The objective of this study was to evaluate the relative efficacy of otoscope cone cleaning and disinfection methods commonly used in veterinary practices. Using sterile technique, 60 new gas-sterilized 4-mm otoscope cones were inoculated with a broth culture of 1.5 billion Pseudomonas aeruginosa bacteria per mL then allowed to dry for 10 min. Six study groups of 10 cones each were created. Group 1 served as positive control and received no cleaning or disinfection. Group 2 cones were wiped with sterile cotton-tipped applicators and gauze then rinsed with water. Group 3 cones were wiped with 70% isopropyl alcohol. Group 4 cones were scrubbed in a speculum cleaner with Cetylcide II solution (Cetylite Industries, Inc., Pennsauken, NJ). Groups 5 and 6 cones were soaked for 20 min in Cetylcide II and chlorhexidine gluconate 2% solutions, respectively. Using sterile technique and after 10-15 min drying time, the cones were swabbed in a consistent pattern, and samples were submitted for quantitative culture. Culture results showed no growth from cones soaked in Cetylcide II or chlorhexidine solutions. Two of the 10 cones wiped with alcohol, 3/10 cones wiped then rinsed with water, and 3/10 cones scrubbed with the speculum cleaner showed growth of P. aeruginosa. All (10/10) cones in the control group showed heavy growth of P. aeruginosa. These results show that P. aeruginosa can survive on otoscope cones cleaned and disinfected by several commonly used methods. Further study is needed to determine practical and optimal cleaning and disinfection methods for otoscope cones.

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.

Effect of tympanic cavity evacuation and flushing on microbial isolates during total ear canal ablation with lateral bulla osteotomy in dogs

OBJECTIVE

To evaluate differences in bacterial numbers, identity, and susceptibility in samples obtained from the tympanic cavity on entry (preflush) and after evacuation and lavage (postflush) and assess perioperative and empiric antimicrobial selection in dogs that underwent total ear canal ablation (TECA) with lateral bulla osteotomy (LBO) or reoperation LBO.

DESIGN

Prospective clinical study.

ANIMALS

34 dogs.

PROCEDURE

TECA with LBO or reoperation LBO was performed on 47 ears. Pre- and postflush aerobic and anaerobic samples were obtained from the tympanic cavity. Isolates and antimicrobial susceptibility patterns were compared.

RESULTS

Different isolates (31/44 [70%] ears) and susceptibility patterns of isolate pairs (6/44 [14%] ears) were detected in pre- and postflush samples from 84% of ears. Evacuation and lavage of the tympanic cavity decreased the number of bacterial isolates by 33%. In 26% of ears, bacteria were isolated from post-flush samples but not preflush samples. Only 26% of isolates tested were susceptible to cefazolin. At least 1 isolate from 53% of dogs that received empirically chosen antimicrobials postoperatively was resistant to the selected drugs. Anaerobic bacteria were recovered from 6 ears.

CONCLUSIONS AND CLINICAL RELEVANCE

Accurate microbiologic assessment of the tympanic cavity should be the basis for selection of antimicrobials in dogs undergoing TECA with LBO. Bacteria remain in the tympanic cavity after evacuation and lavage. Cefazolin was a poor choice for dogs that underwent TECA with LBO, as judged on the basis of culture and susceptibility testing results.

A real-time PCR assay to detect the Panton Valentine Leukocidin toxin in staphylococci: screening Staphylococcus schleiferi subspecies coagulans strains from companion animals

Recent reports suggest that methicillin-resistant strains of Staphylococcus schleiferi subspecies coagulans are now commonly isolated from dogs. Given the association of a potentially mobile SCCmec type IV element with lysogenic phage-encoded Panton Valentine Leukocidin (PVL) toxin genes in community-acquired methicillin-resistant Staphylococcus aureus strains we hypothesized that methicillin-resistant S. schleiferi ssp. coagulans strains may also encode PVL toxin genes. Forty S. schleiferi ssp. coagulans strains isolated from companion animals were studied. Susceptibility to oxacillin was determined by broth microdilution and all isolates were screened by PCR for the presence of the mecA gene. SCCmec typing was performed on 14 isolates. A real-time PCR assay was developed for the detection of the PVL genes using a SmartCycler. Pulsed-field gel electrophoresis (PFGE) was performed to determine whether S. schleiferi ssp. coagulans strains were homogeneous. Twenty-eight of the 40 isolates (70%) were resistant to oxacillin and 26/28 possessed the mecA gene by PCR. SCCmec IV was identified in seven strains; the other seven isolates were not typable by this technique. All 40 strains were negative for the PVL toxin gene. PFGE showed a heterogeneous population and 13 different profiles were determined. In conclusion, this study showed that PVL toxin genes were not detected in a heterogeneous population of methicillin-resistant S. schleiferi ssp. coagulans strains isolated from companion animals.

Brainstem and cranial nerve abnormalities: listeriosis, otitis media/interna, and pituitary abscess syndrome

This article reviews three disorders associated with multiple asymmetric cranial nerve deficits in ruminants: encephalitic listeriosis,otitis media/interna, and pituitary abscess syndrome. Emphasis is placed on encephalitic listeriosis, an infectious disease of the brainstem and cranial nerves caused by Listeria monocytogenes. The epidemiology, pathophysiology, clinical manifestations, diagnosis,and treatment of encephalitic listeriosis are reviewed, and differences between cattle and small ruminants are noted. Physical and neurologic examination findings that distinguish otitis media/interna and pituitary abscess syndrome from encephalitic listeriosis are highlighted.

Otitis media in dairy calves: a retrospective study of 15 cases (1987 to 2002)

Epidemiological data, clinical signs, complementary examination findings, antimicrobial treatments, and outcome were reviewed in 15 calves diagnosed with otitis media at the Centre hospitalier universitaire vétérinaire de l'Université de Montréal between 1987 and 2002. Age at presentation ranged from 2 to 18 weeks. A purulent ear discharge and epiphora were seen in 8/12 and 6/15 cases, respectively. Neurological signs observed were head tilt (13), eyelid ptosis (7), paresis/paralysis of the pinna (8), ataxia (2), strabismus (2), and convulsions (1). Concurrent pneumonia was frequently diagnosed (n = 11). A Mycoplasma sp. was the principal pathogen isolated from ear discharge; 6 out of 6 samples submitted were positive for mycoplasma. Tympanic bullae radiographs were considered abnormal in 12 out of 13 cases. Cerebrospinal fluid analysis was considered abnormal in 2 out of 5 cases. The antibiotic most commonly used was enrofloxacin (n = 7). Average treatment duration was 19.6 days. Four out of 8 treated animals for which follow-up information was available completely recovered. These results suggest that M. bovis is a major pathogen of otitis media in dairy calves and effective antimicrobial therapy should be of long duration.

Evaluation of outcome of otitis media after lavage of the tympanic bulla and long-term antimicrobial drug treatment in dogs: 44 cases (1998-2002)

OBJECTIVE

To evaluate the outcome of otitis media in dogs after video-otoscopic lavage of the tympanic bulla and long-term antimicrobial drug treatment.

DESIGN

Retrospective study.

ANIMALS

44 dogs with otitis media treated in an academic referral practice.

PROCEDURE

Medical records were reviewed for signalment, duration of ear canal disease, previous medical treatments, dermatologic diagnosis, results of cytologic examination and microbial culture of ear canal exudate, findings during video-otoscopy, medical treatment, days to resolution, and maintenance treatments prescribed. Four independent variables (age, duration of ear canal disease prior to referral, use of corticosteroids in treatment regimens, and infection with Pseudomonas aeruginosa) were evaluated statistically for potential influence on time to resolution.

RESULTS

Mean +/- SD (range) duration of ear canal disease prior to referral was 24.9 +/- 21.6 (3 to 84) months. Otitis media in 36 dogs resolved after lavage of the tympanic bulla and medical management; mean +/- SD (range) time to resolution was 117 +/- 86.7 (30 to 360) days. Time to resolution was not significantly influenced by any variable evaluated. Three dogs were lost to follow-up, and 4 dogs eventually required surgical intervention. Seven of 36 dogs in which otitis had resolved relapsed; 4 required additional lavage procedures.

CONCLUSIONS AND CLINICAL RELEVANCE

Results indicate that lavage of the tympanic bulla combined with medical management is an effective and viable option for treatment of otitis media in dogs.

Ear cleaning: the UK and US perspective

Ear cleaning helps maintain the normal otic environment and is important in the treatment of otitis. Over cleaning, however, may trigger otitis through maceration of the epidermal lining. Simple manual cleaning is useful for routine cleansing but doesn't remove tightly adherent debris. Bulb syringes are more vigorous but may damage the ear in inexperienced hands. Devices using mains water pressure or dental machines are also available. Thorough cleaning of the ear canals and middle ear cavity can only be achieved by retrograde flushing using specially adapted catheters, feeding tubes or video otoscopes under anaesthesia. Myringotomy, inspection and cleaning of the middle should be performed if the tympanic membrane appears abnormal. There are a wide variety of cleaning fluids available. Ceruminolytics soften and dissolve cerumen to facilitate cleaning. Surfactants emulsify debris, breaking it up and keeping it in solution. Astringents dry the ear canal surface, preventing maceration. Maintaining a low pH and incorporating antimicrobial agents can inhibit microbial proliferation and glucocorticoids can be used to reduce inflammation. Adverse effects and contraindications following ear cleaning can include maceration, contact reactions, otitis media, ear canal avulsion, vestibular syndrome, Horner's syndrome, facial nerve paralysis and deafness. Care should be exercised in selecting cleaning fluids if the tympanic membranes are ruptured.

Material in the middle ear of dogs having magnetic resonance imaging for investigation of neurologic signs

The aim of this study was to determine the prevalence and potential significance of finding material in the middle ear of dogs having magnetic resonance (MR) imaging. Of 466 MR studies reviewed, an increased signal was identified in the tympanic bulla in 32 (7%) dogs. Cavalier King Charles spaniels, Cocker spaniels, Bulldogs, and Boxers were over-represented compared to the population of dogs having MR imaging. Five (16%) dogs had definite otitis media and one (3%) had a meningioma invading the middle ear. Of the remaining dogs, 13 (41%) had possible otitis media and 13 (41%) had neurologic conditions apparently unrelated to otitis media. The most common appearance of material in the middle ear was isointense in T1-weighted images and hyperintense in T2-weighted images. There was no apparent correlation between the signal characteristics of the material and the diagnosis. Enhanced signal after gadolinium administration was observed affecting the lining of the bulla in dogs with otitis media and in dogs with unrelated neurologic conditions. In dogs without clinical signs of otitis media, finding an increased signal in the middle ear during MR imaging may reflect subclinical otitis media or fluid accumulation unrelated to inflammation. Brachycephalic dogs may be predisposed to this condition.

Medical therapy of otitis externa and otitis media

Medical regimens for the successful treatment of infectious otitis may vary widely depending on the degree of pathologic changes of the external ear canals, the status of the tympanic membranes, and the specific microorganisms involved. Chronic otitis media is especially problematic, because impaction of the bullae can be difficult to resolve and these cases often involve antibiotic-resistant bacterial organisms. In fact, the continuing emergence of resistant Pseudomonas spp and Staphylococcus spp will ensure that the medical therapy of otitis remains a dynamic art for the foreseeable future. This article considers the specific antimicrobial agents available for otic use, their potential toxicities, and guidelines for their use.

Diagnosis and treatment of otitis media in dogs and cats

Otitis externa/media is commonly found in dogs with chronic ear diseases and in cats with upper respiratory disease and polyps. Diagnosis of otitis media requires attention to history and clinical signs, but it also requires other methods of determining disease within the bulla. If the integrity of the eardrum cannot be determined, assume that there is middle ear disease and proceed accordingly. It is prudent to take necessary precautions to avoid the use of potentially ototoxic ear cleaners or topical medications in suspected otitis media cases. Therapeutic success is possible using systemic and topical treatment within the cleaned bulla. Referral to a dermatology specialist or a radiologist for a CT scan may be indicated in some refractory cases. Surgical intervention may be required to cure these difficult cases.

Comparison of ultrasonography, radiography and a single computed tomography slice for the identification of fluid within the canine tympanic bulla

Fluid accumulation within the tympanic bulla (TB) is an important diagnostic indicator in clinical cases of canine otitis media although its identification can be a challenge using currently available imaging techniques. The aim of this study was to compare ultrasound with radiography and a single computed tomography (CT) slice for the identification of fluid within the TB of canine cadavers. A random number of TB in 66 cadavers were filled with ultrasound gel. Rostrocaudal open mouth (RCdoM) radiographs and CT images were interpreted by 2 blinded radiologists and ultrasound examinations were performed by 2 blinded sonographers. The heads were then frozen and sectioned to confirm the contents of each TB. Although CT remained the most accurate method, comparable results were obtained by one of the sonographers and even the inexperienced sonographer produced results superior to radiography. Ultrasound has several advantages over the other imaging techniques and this study suggests that it may have an application in the investigation of canine otitis media although further work in live animals would be required to confirm this.

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.

Ultrasonography versus radiography for detection of fluid in the canine tympanic bulla

The tympanic bullae of 20 previously healthy cadaver animals were randomly filled with sterile saline or air. The heads were positioned using tape ties and a rostrocaudal open mouth radiograph taken. The resulting radiographs were assessed by a blinded ECVDI diplomate, with each tympanic bulla being recorded as being either air or fluid filled. Ultrasound examination of the bullae was performed, by a blinded assessor, using a B-mode 5 mHz sector probe (Sonotron-VingMed Sound A/S, PO Box 141, N3191, Horten, Norway) operating at 3 mHz. Each bulla was recorded as being either air or fluid filled. Results of radiography and ultrasonography were each compared to the actual status of the bulla in a chi square analysis. Sensitivity of radiography was 80%, with specificity of 65%. Ultrasonographic sensitivity was 100% and specificity 100%. Ultrasonography may in future provide a cheap, noninvasive, rapid and widely available method for diagnosing otitis media in clinical cases.

Otolithiasis in three dogs

Mineral opacities within the tympanic bullae, termed otoliths, were detected in three dogs by means of radiography and computed tomography. Radiographic signs of otitis externa were present in two dogs. One dog had clinical signs of vestibular disease, whereas the other two dogs had no clinical evidence of ear disease. Otolithiasis may represent mineralized necrotic material of a current or previous case of otitis media.

A review of techniques for the investigation of otitis externa and otitis media

Otitis externa, inflammation of the externa ear canal, is relatively easy to diagnose based on the history and physical examination findings. The diagnosis of otitis media, inflammation of the middle ear cavity, is more challenging, with the work-up being both costly and, at times, invasive. The pathogenesis of otitis externa has been classified into predisposing, primary, and perpetuating factors. It is critical to the management of ear disease that the clinician recognize and investigate which factors are contributing to each individual patient's ear disease. Failure to identify and address the primary and/or predisposing factors is the most common cause of chronic recurrent otitis externa. Chronic inflammation of the ear canal leads to the development of the perpetuating factors, which may be the major reason for treatment failure, regardless of the primary cause of the ear disease. In this article, the predisposing, primary, and perpetuating factors involved in ear disease will be presented, along with a review of the techniques used in the diagnosis of otitis externa and otitis media.

[Early auditory evoked potentials (EAEPs) for the clinical diagnosis of otitis media in the rabbit]

The main objectives of the study presented here were to prove the early auditory evoked potentials (EAEPs) as an objective procedure to confirm the diagnosis of otitis media in the rabbit. Therefore, in a clinical study the latencies and amplitudes of the EAEPs of 67 (ear) healthy rabbits were determined at sound pressure levels (SPLs) of 80, 60 and 40 dB. In comparison, the EAEPs of 9 rabbits with otitis media/interna were measured and the deviation of the latencies and amplitudes statistically analysed. The rabbits (no clinical signs of ear disease) showed at 80 dB SPLs the following latencies: potential 0 appeared with 0.53 ms (= average latency, +/- 0.12 ms standard deviation), potential I with an average latency from 1.26 (+/- 0.13) ms, potential II with 2.04 (+/- 0.14) ms, potential III with 2.71 (+/- 0.13) ms, potential IV with 3.72 (+/- 0.17) ms and potential V, which often was difficult to recognize, had an average latency of 4.62 (+/- 0.30) ms. In comparison to these results the rabbits with otitis media showed significant longer latencies at a sound pressure level of 80 dB for potential II, III and IV. Altogether, all mean values of latencies were prolonged in the affected rabbits. The amplitudes of the potentials of the rabbits without clinical signs of ear disease had a broad mean variation with large individual differences. The comparison of the results of EAEPs between rabbits with and without otitis media showed some differences of the latencies but these differences were not obviously enough to confirm the diagnosis of otitis media. Overall, the results showed that EAEPs with only three different sound pressure levels give no convincing results, although extensively prolonged latencies could lead suspicion on the diagnosis of otitis media. Further studies about the ascertainment of the objectively acoustic threshold in the rabbit with otitis media are necessary. The comparison of the latencies and amplitudes in the EAEPs between male and female rabbits showed longer latencies of potential III for male rabbits at 80 and 60 dB SPLs. Furthermore the results of latencies and amplitudes were compared between dwarf rabbits and other breeds. In dwarf rabbits (with an average body weight of 1420 g) significant higher amplitudes for the potentials I, II, IV and V were detectable than in other breeds (with an average body weight of 2852 g). This can be due to different body mass or different headsize.

Evaluation of different preservation and storage methods for Malassezia spp

Freezing at -80 degrees C, lyophilization, preservation in distilled water, and storage in different culture media were performed in order to find a suitable method that allowed a prolonged storage of Malassezia spp. Freezing at -80 degrees C was the only method successful at maintaining all species.

Magnetic resonance imaging of the normal and diseased feline middle ear

The magnetic resonance imaging appearance of the feline middle ear is described in three healthy cats and in five cats with middle ear disease. Owing to the good spatial resolution, multiplanar slice orientation as well as display high contrast resolution of soft tissue, in particular fluids, MR imaging was helpful prior to surgery. It is superior to radiography which failed to allow identification of the abnormality in two of our five cats. MR imaging for middle ear disease should include dorsal and transverse plane images using T1- and T2-weighted sequences. In the presence of a mass within the bulla or the external ear canal application of contrast medium is helpful.

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.