CONTRAST-ENHANCED COMPUTED TOMOGRAPHIC IMAGING OF THE AUDITORY TUBE IN MESATICEPHALIC DOGS

Computed tomography after contrast medium injection was performed in three mesaticephalic canine cadavers to image the auditory tube. Cadavers were positioned in lateral recumbency for imaging. A myringotomy incision was made in the left tympanic membrane of each dog, and contrast medium was infused into the ear canal and middle ear through a balloon-tip catheter. With this method, contrast medium filled the left bulla and auditory tube in all three cadavers. Computed tomography following contrast medium injection was effective for evaluation of the canine auditory tube. Future studies are required to determine the usefulness, as well as the safety, of this procedure in the evaluation of the auditory tube in other breeds of dogs as well as dogs with otitis     

Tracheal resection and anastomosis for congenital stenosis in a dog

A one-year-old Cocker Spaniel dog was presented for the investigation of exercise-related stridor and respiratory embarrassment evident since birth. Radiography demonstrated a segmental tracheal stenosis at the thoracic inlet which was found to result from the congenital absence of tracheal rings at this point. The stenotic segment was resected at surgery and an end-to-end tracheal anastomosis performed. The dog now enjoys normal respiratory and exercise function with minimal narrowing of the trachea at the site of the anastomosis.     

Surgical management of 2 different presentations of ear canal atresia in dogs

A 6-year-old French spaniel and a 14-month-old German shepherd dog were diagnosed with ear canal atresia. Based on presentation, computed tomography, and auditory function evaluation, the first dog underwent excision of the horizontal ear canal and bulla curettage, and the second underwent re-anastomosis of the vertical canal to the external meatus. Both dogs had successful outcomes.     

Systematic identification of endobronchial anatomy during bronchoscopy in the dog

The endobronchial anatomy of 10 inflated, air-dried, canine lungs and 8 healthy anesthetized, sternally recumbent, mixed-breed dogs was evaluated, using a flexible fiberoptic bronchoscope. On the basis of the order of branching of lobar and segmental bronchi observed in these lungs, a nomenclature system was devised to systematically identify individual lobar, segmental, and subsegmental bronchi during bronchoscopy in the dog.     

External auditory canal atresia of probable congenital origin in a dog

A nine-month-old Labrador retriever was referred to the Clinica Veterinaria Privata San Marco because of frequent headshaking and downward turning of the right ear. Clinical examination revealed that there was no external acoustic meatus in the right ear. Computed tomography confirmed that the vertical part of the right auditory canal ended blindly, providing a diagnosis of external auditory canal atresia. Cytological examination and culture of fluid from the canal and the bulla revealed only aseptic cerumen; for this reason, it was assumed that the dog was probably affected by a congenital developmental deformity of the external auditory canal. Reconstructive surgery was performed using a "pull-through" technique. Four months after surgery the cosmetic and functional results were satisfactory.     

Multifocal odontoblastic dysplasia in a dog

A two-year-old Boerboel dog presented for a discolored left maxillary canine tooth. Dental radiographs revealed abnormally mineralized pulp within the discolored tooth. Similar radiographic findings were also seen in both maxillary third incisor teeth and in the remaining canine teeth to varying degrees. The discolored tooth was treated by surgical extraction and histopathology revealed abnormal dentin deposition within the canal indicative of dentin dysplasia. Although not previously documented in the dog, the pulpal changes in multiple teeth of the dog reported here were similar to those described for odontoblastic dysplasia in humans. This case report includes a review of developmental abnormalities of dentin in humans and pulpal response to inflammation and injury.     

Omentalisation of a caudal mediastinal abscess in a dog

A caudal mediastinal abscess was diagnosed in a 2-year-old German Short-haired Pointer with acute onset of lethargy, pyrexia and tachypnoea. The abscess was managed surgically by median sternotomy, abscess content evacuation and omentalisation of the abscess cavity via the diaphragm. Although surgical management of mediastinal abscesses has been reported previously, this is the first report to describe successful management of the condition in a dog by omentalisation.     

Segmental inertial properties in dogs determined by magnetic resonance imaging

Data regarding the segmental inertial properties of the dog are currently unavailable, although such parameters are needed for dynamic analyses of canine motion. The purpose of this study was to measure the segmental inertial properties in three medium sized dogs of average build using magnetic resonance imaging. The parameters included the mass, location of centre of mass and moments of inertia for each body segment. The normalised results will serve as a preliminary foundation for various biomechanical studies in dogs, although further study is required to characterise them for specific dog breeds and to determine how they may be affected by age and gender.     

Phase II study of oral docetaxel and cyclosporine in canine epithelial cancer

The goal of the current study was to determine the efficacy of oral docetaxel in combination with cyclosporine in the treatment of canine epithelial cancer. Requirements for eligibility were histological confirmation of epithelial neoplasia, measurable disease, no chemotherapy treatment within 2 weeks, and a life expectancy of ≥3 months. Fifty‐one dogs were enrolled. All dogs received 1.625 mg kg^?1 of docetaxel with 5 mg kg^?1 of cyclosporine (DT/CSA) by gavage. Ten dogs had progressive disease at 2 weeks, one dog died, and one dog was withdrawn from the study. Thirty‐nine dogs were given a second dose of DT/CSA, three each receiving a third or fourth dose. Eight dogs had a dose reduction (1.5 mg kg^?1) and six dogs had treatment delays primarily for gastrointestinal toxicity. The overall response rate was 16.7% (8/48 had a partial response there were no complete responses). The highest response rate was seen in dogs with oral squamous cell carcinoma (50%; 6/12).     

Radiographic findings and clinical factors in dogs with surgically confirmed or presumed colonic torsion

Colonic torsion is a life‐threatening condition in dogs and radiographic findings for this condition have not been well described. The purpose of this retrospective case series was to describe radiographic findings and clinical signs in a group of dogs with colonic torsion. Inclusion criteria were dogs presenting during the period of 2006 and 2016, and that had abdominal radiography and a surgically confirmed or presumed diagnosis of colonic torsion. For each dog, clinical data were recorded from medical records and imaging findings were recorded from retrieved plain radiographs and positive contrast radiographs in which barium enema was performed. Fourteen dogs met inclusion criteria. Of these, nine dogs had colonic torsion confirmed at surgery, with five dogs having surgical confirmation of colonic congestion or mesenteric torsion. Radiographic findings included segmental distention of the colon (14/14), focal narrowing of the colon (11/14), displacement of cecum (11/14), displacement of descending colon (14/14), and mild to no small intestinal distention (14/14). In cases where barium enema was performed, focal narrowing of the colon and longitudinal striations that course in a helical pattern were identified, termed the “torsion sign.” Vomiting was the most common clinical sign observed (12/14), followed by abdominal pain in a small majority of cases (8/14). Severe abdominal pain and hypovolemic shock were uncommon in the patients reported (3/14). Colonic torsion should be considered as a differential diagnosis for dogs with radiographic segmental colonic distention with displacement of the descending colon and cecum. Barium enema is recommended for more definitive diagnosis.     

Microneurovascular Free Digital Pad Transfer in the Dog

By cadaver dissections, the fifth digit of the canine hind limb was determined to have a consistent neurovascular anatomy, and therefore be a suitable donor for an axial pattern digital pad flap. The defined digital pad flap was transferred to the region of an excised metacarpal pad by microneurovascular anastomoses in five operations on four dogs. One flap failure was considered to result from failure of the venous anastomosis. In all four successful transfers, cutaneous sensation was reestablished on average in 78 days. There was histologic evidence of nerve regeneration across the anastomosis in one dog at week 24. The transferred pads of three dogs monitored for 15 months underwent hypertrophic changes. There were no complications in two active dogs. In one dog, superficial ulceration of a region of the flap adjacent to the pad required surgical revision. This dog continued to show mild lameness after daily runs of 3 to 4 km.     

Canine cutaneous epitheliotropic T‐cell lymphoma: a review

Cutaneous epitheliotropic T‐cell lymphoma in the dog is a rare neoplastic condition with unknown aetiology. The dermatitis is characterized by infiltration of neoplastic T lymphocytes with a specific tropism for the epidermis and the adnexal structures. The different clinical and histological forms (mycosis fungoides, pagetoid reticulosis and Sézary syndrome) are reviewed. The disease in the dog resembles the human syndrome, but in 80% of the canine cases, neoplastic cells are CD4^?/CD8⁺ versus CD4⁺/CD8^? in 90% of the human patients. Prognosis is poor with a survival time from few months to 2 years. Treatments frequently have a low efficacy. New protocols using lomustine may improve the poor prognosis of the disease.     

Use of CD9 and CD61 for the characterization of AML‐M7 by flow cytometry in a dog*

Acute megakaryoblastic leukaemia (AML‐M7) is a rare myeloproliferative disorder in domestic animals. Recently, thanks to the greater availability of immunophenotype techniques, precise diagnosis is more easily made. The morphological evaluation has its limitations, especially in the study of poorly differentiated cells. Few reports have described AML‐M7 in dogs using flow cytometry. This clinical case points out the utility of flow cytometry in the characterization of AML‐M7 in a 3‐year‐old German Shepherd dog. Flow cytometry investigation has established megakaryocytic lineage involvement by showing the presence of two megakaryocyte/platelet associated antigens (CD9 and CD61). In human medicine CD9 may be used as a platelet and megakaryocyte marker. There is an evidence of cross‐reactivity of human anti‐CD9 monoclonal antibody with canine samples. To our knowledge, the use of CD9 has never been described before, for this purpose in the dog.     

Aural cholesterol granuloma in a dog

A five-year-old female Irish setter was referred for surgery for a left-sided aural mass. The dog was generally well, but had signs of left-sided otalgia for one week. Biopsy identified the lesion as a cholesterol granuloma. The mass was removed three weeks later by a total canal ablation/lateral bulla osteotomy. The dog recovered from surgery without any complications. Ten months later, there was no evidence of recurrence. The purpose of this paper is to report the clinical and histopathological findings of this unusual form of granuloma which has not previously been reported in the canine ear.     

An end‐to‐end urethral anastomosis after inguinal tunnelization: a new technique in a dog

An 8‐year‐old male dog was presented with a peri‐urethral intrapelvic mass with the characteristics of a sarcoma on computed tomography and cytology evaluation. A two‐step procedure leading to a permanent urinary diversion was performed. During the same procedure, the caudal pelvic urethra and mass were resected and an extrapelvic anastomosis of the pelvic portion of the urethra to its penile portion was performed after passage of the pelvic urethra through the inguinal canal. The procedure successfully produced a tension‐free end‐to‐end urethral anastomosis and no complications were observed during the postoperative period. Histologically, the lesion was reported as a narrowly excised liposarcoma. A 4‐week course of curative intent of radiotherapy was initiated 2 weeks after surgery. Eight months later, the dog was free of clinical signs.     

Experimental Use of Fluoroalkyl Cyanoacrylate in Canine Urethral Anastomosis

The results of a study designed to evaluate a fluoroalkyl cyanoacrylate tissue adhesive as an adjunct to suture anastomosis of the severed canine pelvic urethra are presented. The urethral anastomotic sites were evaluated by contrast radiography, gross pathology, and histopathology. Urethral anastomosis resulted in a clinically functional urethra in all 6 control dogs (suture anastomosis) and 5 of the 6 test dogs (suture anastomosis plus adhesive). A severe stricture at the anastomotic site developed in 1 dog in the test group. Evidence of leakage was detected by contrast radiography in 1 dog of each group. Microscopic evidence of incomplete closure was detected in 4 control dogs and 2 test dogs. An extensive granulomatous inflammatory reaction was associated with use of the adhesive. The lower incidence of microscopic leakage observed in the test dogs was attributed to fibroplasia induced by the cyanoacrylate and not to the adhesive properties of the cyanoacrylate.     

Clinical outcome in 23 dogs with exocrine pancreatic carcinoma

Exocrine pancreatic carcinoma is uncommon in the dog and the veterinary literature surrounding the disease is minimal. Twenty‐three cases of canine exocrine pancreatic carcinoma were reviewed in a retrospective manner to obtain information on clinical presentation, behaviour and survival associated with the disease. Presenting clinical signs were nonspecific and included anorexia, lethargy, vomiting and abdominal pain. The overall median survival time was only 1 day but was confounded by the large number of dogs that were euthanized shortly after diagnosis. Metastatic disease was detected in 78% of cases at the time of diagnosis, attesting to the aggressive nature of the disease. Neither lymph node metastasis, tumour size nor tumour location had an impact on overall survival. Only one patient was a previous diabetic who is contrary to reports of the disease in people and felines. This retrospective study reaffirms the need for early detection measures to optimize disease control. However, the benefits of therapy with surgery or radiation and adjuvant chemotherapy remain to be elucidated in dogs with exocrine pancreatic carcinoma.     

Outflow tract segmental arrhythmogenic right ventricular cardiomyopathy in an English Bulldog

A 5-year-old English Bulldog was presented for acute onset of syncope and fatigue caused by sustained ventricular tachycardia with left bundle block morphology and inferior axis. This arrhythmia had the electrocardiographic features of a ventricular tachycardia arising from the right ventricular outflow tract (RVOT), as described in an experimental canine model and in people. Since a RVOT aneurysm was identified by echocardiography, a segmental form of arrhythmogenic right ventricular cardiomyopathy (ARVC) was suspected. Gross examination of the heart confirmed the bulging of the RVOT and histological examination of the ventricular myocardium revealed segmental involvement of the RVOT with transmural fibro-fatty degeneration. To the authors' knowledge, this is the first reported case of AVRC in an English Bulldog and the first example of segmental AVRC described in the dog.     

Inductively coupled plasma mass‐spectrometric determination of platinum in excretion products of client‐owned pet dogs

Residues of antineoplastic drugs in canine excretion products may represent exposure risks to veterinary personnel, owners of pet dogs and other animal care‐takers. The aim of this study was to measure the extent and duration of platinum (Pt) excretion in pet dogs treated with carboplatin. Samples were collected before and up to 21 days after administration of carboplatin. We used validated, ultra‐sensitive, inductively coupled plasma‐mass spectrometry assays to measure Pt in canine urine, faeces, saliva, sebum and cerumen. Results showed that urine is the major route of elimination of Pt in dogs. In addition, excretion occurs via faeces and saliva, with the highest amounts eliminated during the first 5 days. The amount of excreted Pt decreased over time but was still quantifiable at 21 days after administration of carboplatin. In conclusion, increased Pt levels were found in all measured excretion products up to 21 days after administration of carboplatin to pet dogs, with urine as the main route of excretion. These findings may be used to further adapt current veterinary guidelines on safe handling of antineoplastic drugs and treated animals.