A novel video-endoscope-guided myringotomy technique in dogs: Investigation in the value of vertical access to the tympanic membrane from beneath the patient - a pilot study.

Myringotomy is a well-accepted method for diagnosing and treating otitis media in dogs having an intact tympanic membrane. In a recent study, the contamination rate of middle ear aspirates from the external ear canal via myringotomy was 67%. To evaluate the iatrogenic contamination rate of the middle ear aspirates by material from the ear canal, using a novel technique: Vertical access to the tympanic membrane from beneath the patient. Thirty-six ears from 20 canine Fresh cadavers with a CT scan negative for otitis externa and otitis media were video-otoscopically flushed with the ear upside. The instillation of the fluorescent dye into the ear canal and immediate retrieval were performed. With the patient positioned on a custom-made fenestrated table plate, a modified video-otoscopically guided myringotomy approaching the tympanum vertically from underneath, was performed. Contamination rates were assessed by the visual detection of fluorescent dye within the aspirated fluid, either by yellow staining solely, or a positive fluorescence test. Cytology and microbial cultivation were accomplished. Middle ear sample contamination by the material from the ear canal was identified in 2 of 36 (5.55%) ears. Neither a change in colour nor fluorescence was detected in 34 of 36 (94.44%) middle ear samples. Sixteen of 36 (44.44%) external ear canal samples and 4 of 36 (11.11%) middle ear aspirates had positive bacterial culture. This novel technique is a promising method for middle ear material collection in patients with concurrent otitis externa.

Myringotomy in dogs: Contamination rate from the external ear canal - a pilot study.

Myringotomy for sample collection from the middle ear cavity for cytology and bacterial culture is considered a routine method to diagnose otitis media in dogs. The objective of this study was to determine the rate of contamination of middle ear aspirates with material from the external ear canal obtained by video-otoscopic guided myringotomy. In canine cadavers (n = 17) free from otitis externa the external ear canals were flushed under video-otoscopic control and a fluorescent dye was instilled. After removal of residual fluid a myringotomy was performed. If air was aspirated, 1 mL of saline was instilled through the same myringotomy needle into the middle ear cavity and re-aspirated. Contamination from the external ear canal was demonstrated by positive fluorescence of the aspirate. Bacterial cultures and cytological examinations of the external ear canals and middle ear cavities were performed. Data from 28 ears under investigation were included. In 19 of 28 middle ear aspirates (67.9%), clear yellow fluorescent fluid was obtained, indicating a contamination from the external ear canal. Microorganisms were detected in 4 of 26 middle ear samples (15.4%) and in 15 of 26 external ear canals (57.7%). Sample collection by myringotomy in this study was associated with a high contamination rate, implying that the suitability of this method for detection of otitis media in patients with concurrent otitis externa is questionable. Furthermore, the potential for iatrogenic spread of pathogenic microorganisms into the middle ear cavity needs to be considered.

Thyroid testing in Sloughis.

BACKGROUND: Thyroid hormone concentrations were found to be different in Greyhounds and Whippets compared with nonsight hound dogs. HYPOTHESIS: In Sloughis, thyroid hormone concentration is lower than in nonsight hounds and comparable to Greyhounds. ANIMALS: Fifty-one Sloughis with no evidence of disease and a mean age of 4 years (range, 1-12 years). METHODS: Thyroid profiles consisting of total thyroxine (tT4), free thyroxine (fT4), free thyroxine after equilibrium dialysis (fT4 after ED), canine thyroid stimulation hormone (cTSH), and thyroglobulin antibodies as well as CBC and serum biochemistry results of Sloughis were compared with those of normal dogs. In 8 Sloughis, TSH stimulation tests were performed. RESULTS: In Sloughis, tT4 concentrations and fT4 concentrations measured by chemiluminescence were lower than those of controls (1.13+/-0.65 microg/dL compared with 2.9+/-0.8 microg/dL, P< .0001 and 11+/-4.3 pmol/L compared with 16.7+/-5.2 pmol/L, P< .0001, respectively). Concentrations of fT4 after ED and TSH were increased in Sloughis, when compared with controls (41.3+/-26.9 pmol/L compared with 20.98+/-10.29 pmol/L, P< .0001 and 0.22 +/- 0.15 pmol/L compared with 0.15+/-0.13 pmol/L, P= .0138, respectively). T4 concentration after TSH stimulation increased from 1.5 microg/dL (range, 0.2-2.7 microg/dL) to 2.7 microg/dL (range, 1.2-4.7 microg/dL); the recommended post-TSH T4 concentration was achieved by only 3 of 8 Sloughis. Hemoconcentration was found in 84.3% and hypoglobulinemia in 80.3%. CONCLUSIONS AND CLINICAL IMPORTANCE: When evaluating Sloughis for hypothyroidism, veterinarians should be aware that these dogs have different thyroid hormone concentrations than nonsight hound dogs.