Evaluation of the canine tympanic membrane by positive contrast ear canalography.

Positive contrast ear canalography was described briefly in 1973 as a method for detecting rupture of the tympanic membrane in dogs with otitis media. The purpose of this study was to evaluate the sensitivity and usefulness of the technique. The ears of 10 normal canine cadavers and 31 dogs with clinical signs of ear disease were examined using otoscopy, radiography and contrast radiography after infusing 2 to 5 ml of positive contrast medium into the ear canals. These examinations were repeated in the cadavers after the tympanic membrane had been punctured with a Spreull needle. In the cadavers 14 of 19 (74 per cent) of the tympanic membranes were visible otoscopically; contrast medium did not enter the tympanic bulla of any of the ears before the tympanic membrane was ruptured, but was visible in the bulla in every ear after rupture. In the clinical study, 40 of 61 (66 per cent) of the tympanic membranes were visible otoscopically, and 12 appeared to be ruptured. Radiographic signs of otitis media (increased opacity and/or thickening of the tympanic bulla) were identified in seven ears. Canalography was positive for rupture of the tympanic membrane in 13 ears, including four in which it appeared to be intact otoscopically. In normal canine ears, canalography was a more accurate method for detecting iatrogenic tympanic membrane rupture than otoscopy. In dogs with ear disease, canalography may be more sensitive for otitis media than either otoscopy or survey radiography.

Arteriovenous fistula involving the prepuce of a dog.

A nine-year-old male Ibizan hound had a network of large tortuous pulsating blood vessels on the prepuce that enlarged gradually over a five month period. A diagnosis of arteriovenous fistula was based on clinical signs, angiography and Doppler ultrasonography. Ligation of the major vascular supply to the fistula resulted in only temporary improvement. Definitive treatment was by wide excision, with penile amputation and scrotal urethrostomy.

Surgical treatment of urinary incontinence resulting from a complex congenital abnormality in two dogs.

Two young dogs were presented for the investigation of urinary incontinence. Both were found to have complex urogenital anatomy including a micropenis and a midline vestibuloperineal fistula situated just below the anus. Both dogs were considered to be intersexes and had the karyotype 78XX. In both cases, incontinence was attributed to increased resistance to the passage of urine, with vaginal reflux and subsequent passive leakage. This report details the investigation of these dogs and their surgical treatment to resolve the urinary incontinence.

A method for controlling portal pressure after attenuation of intrahepatic portacaval shunts.

Two dogs had right divisional intrahepatic portacaval shunts within the right lateral lobe of the liver. In both dogs, an extrahepatic portacaval vascular anastomosis was created, using an autologous right external jugular vein graft. The intrahepatic shunts were completely attenuated using a prehepatic intravascular caval approach. The creation of the vascular graft allowed postattenuation rises in portal pressure to be controlled, preventing the development of life threatening portal hypertension. Both dogs recovered from the procedure. One dog is clinically normal and does not require medication (8 months postoperatively); the other dog was euthanatized 5 months after surgery because of renal failure. Scintigraphy studies, performed before surgery, showed significant shunting of portal blood away from the liver (shunt indices 65% and 59%), whereas, similar studies done 4 weeks afterwards showed almost normal portal blood flow (shunt indices 16% and 18%, respectively).

Ultrasound-guided catheter biopsy of the lower urinary tract: technique and results in 12 dogs.

Ultrasound-guided catheter biopsy of lesions affecting the lower urinary tract was attempted in 12 dogs with mucosal lesions affecting the bladder (nine) or urethra (three). Histological biopsies were obtained by catheter biopsy in 10 dogs, enabling diagnosis of transitional cell carcinoma in five, papilloma in two, prostatic carcinoma in two and chronic cystitis in one. Cytological samples alone were obtained in two dogs, one of which enabled a diagnosis of transitional cell carcinoma; the other contained evidence of haemorrhage and inflammation, but squamous cell carcinoma was found in a subsequent excisional biopsy. Intravesicular haemorrhage after biopsy was observed ultrasonographically in two dogs. Ultrasound guidance enables accurate determination of biopsy catheter position. The size of biopsies obtained by this method may limit the accuracy of histological diagnosis.