Outcomes of surgically treated sialoceles in 21 cats: A multi-institutional retrospective study (2010-2021).

OBJECTIVE: To report the outcomes of cats that underwent surgical correction for sialoceles. STUDY DESIGN: Multi-institutional retrospective cohort study. ANIMALS: Twenty-one client-owned cats. METHODS: Medical records were examined of cats diagnosed with sialocele, which underwent surgical intervention over an 11-year period at one of 10 referral hospitals. The data collected included signalment, clinical signs, diagnostic imaging, histopathology, surgical procedures performed, and postoperative complications. RESULTS: The most common presenting complaints for cats with sialocele included dysphagia and ptyalism. Only two cats had a recent history of trauma, and one was diagnosed with a concurrent sialolith. Most displayed visible tissue swelling, with ranulae being most common. Surgical treatment consisted of sialoadenectomy and/or marsupialization. Intraoperative complications occurred in three cats, and postoperative complications in five cats. No recurrence or development of contralateral sialoceles were reported during the follow-up period (30-968 days). CONCLUSION: The majority of cats did not have a clear underlying cause for developing a sialocele. The sublingual and mandibular salivary glands were presumed to be the most commonly affected. Mandibular and sublingual sialoadenectomy and/or marsupialization provided resolution of clinical signs to the 21 cats that underwent these procedures. CLINICAL SIGNIFICANCE: Sialocele, although rare, should remain a differential diagnosis when managing cats with relevant clinical signs. Surgical intervention appears to offer resolution of signs with apparently low overall risk of complication or short-term recurrence. In cats it is necessary to evaluate whether sialoadenectomy is necessary, or whether marsupialization alone should be attempted as a less invasive first-line surgical intervention.

Pilot Study Evaluating the Use of Typodonts (Dental Models) for Teaching Veterinary Dentistry as Part of the Core Veterinary Curriculum.

Periodontal disease is one the most common disease pathologies in small animal medicine, yet new graduates report they feel unprepared to perform dentistry in general practice. Novel methodologies to close the knowledge gap in veterinary dentistry need to be identified. Typodonts (dental models) are commonly used in human dental schools to teach basic principles prior to practice on clinical patients and have been shown to be an effective teaching tool. The study aimed to determine if independent study and self-guided practice on a veterinary typodont prior to a structured, in-person cadaver laboratory with feedback increases students' perceived dentistry clinical skills in performing periodontal techniques. We calculated the knowledge gap before and after the cadaver laboratory by comparing the students' perceived and desired skill levels in performing periodontal charting, ultrasonic cleaning, hand scaling, and root planing. Ninety-six percent of students reported that practice with the dental typodont prior to the cadaver laboratory increased their comfort level in performing periodontal skills. However, practice did not result in a significant decrease in knowledge gap compared with participation in the cadaver laboratory alone. Although students perceived a benefit to practicing with the typodont, self-guided practice was not effective in decreasing the knowledge gap, most likely due to a lack of structured feedback with typodont use. Further investigation into the use of typodonts with direct feedback prior to structured laboratory or, alternatively, as an additional practice tool following a structured laboratory would further define if there is a benefit to typodont practice in veterinary dentistry.

Influence of skull biometrics on cosmetic reconstruction after incisivectomy and nasal planectomy reconstruction in dogs.

OBJECTIVE: To identify biometric skull measurements that are associated with tension and excess narrowing of the resultant nasal aperture during cosmetic nasal planectomy reconstruction. STUDY DESIGN: Ex vivo study. ANIMALS: Twenty cadavers of mesocephalic dogs. METHODS: Cosmetic reconstruction was performed after incisivectomy and nasal planectomy. Preoperative and intraoperative skull measurements included width of the nasal planum, rostral and caudal maxilla, labial flap, and maxilla at ostectomy site; the length of the nose, labial flap, and philtrum incision; lip thickness; and philtrum placement. Ratios of select width to length measurements were calculated. Correlation was tested between skull biometrics and tension during reconstruction as well as resulting opening of the nasal aperture. RESULTS: Breeds included golden retriever, pit bull, Labrador retriever, beagle, shepherd, basset hound, boxer mix, cocker spaniel, and Great Dane. No biometric ratios were predictive of procedural success. The most important objective measurements that were significantly correlated with inferior outcome included width of the nasal planum (>3 cm), width of the caudal maxilla (>6.2 cm), lip thickness (>0.5 cm), width of the labial flap (>2.9 cm), length of the incision created to make the cosmetic "philtrum" (longer incisions >2.8 cm), and philtrum placement (more dorsal placement). CONCLUSION: Tension during reconstruction and decreased resultant nasal aperture were associated with wider facial features and thicker lips as well as directly impacted by cosmetic philtrum design and placement. CLINICAL SIGNIFICANCE: Standardized preoperative measurements may help guide clinical decision making in choosing and executing a nasal planectomy reconstructive technique.

Clinical Characterization of Canine Acanthomatous Ameloblastoma (CAA) in 263 dogs and the Influence of Postsurgical Histopathological Margin on Local Recurrence.

Canine acanthomatous ameloblastoma (CAA) has been reported to be the most common odontogenic tumor in dogs. This retrospective study evaluated 263 dogs with histopathologically confirmed CAA. Within this data set, CAA presents most commonly in the rostral mandible in adult large breed dogs, with golden retriever dogs being overrepresented. Patients with appropriate follow-up after curative intent surgery were evaluated to assess the effect of histopathological margin on local tumor recurrence. No local recurrence was noted in any patient. This study raises questions about what the recommended surgical margin should be for treatment of CAA. It also serves as a stimulus for discussion as to whether further treatment for CAA is required when inadequate surgical margins are obtained, or if medical surveillance would be an appropriate management recommendation. Prospective studies are necessary to answer these questions.

The Influence of Force Direction on the Fracture Pattern and Fracture Resistance of Canine Teeth in Dogs.

Biomechanical studies of the elongated canine tooth of animals are few, and thus our understanding of mechanical and physical properties of animal teeth is limited. The objective of the present study was to evaluate the influence of force direction on fracture resistance and fracture pattern of canine teeth in an ex vivo dog cadaver model. Forty-five extracted canine teeth from laboratory beagle dogs were standardized by hard tissue volume and randomly distributed among 3 force direction groups. The teeth were secured within a universal testing machine and a load was applied at different directions based on testing group. The maximum force to fracture and the fracture pattern classification were recorded for each tooth. After correcting for hard tissue cross-sectional area in a multivariate analysis, no significant difference in the amount of force required for fracture was apparent between the different force direction groups. However, the influence of force direction on fracture pattern was significant. The results of this study may allow the clinician to educate clients on possible causal force directions in clinically fractured teeth and, thus, help prevent any contributing behavior in the future.

Apical Microleakage in Root Canals Obturated With 2 Different Endodontic Sealer Systems in Canine Teeth of Dogs.

An apical dye leakage test was utilized to compare 2 endodontic sealer systems commonly used in veterinary endodontic treatment. Rotary instrumentation followed by injection of 2 different sealers (GuttaFlow 2 and AH Plus) and a single master cone obturation technique were compared. Following obturation and restoration, specimens were immersed in India ink for 48 hours. A tooth mineral clearing technique was utilized to render the tooth samples transparent. Subsequently, the apices were evaluated for prevalence and magnitude of apical dye penetration under magnification. Statistical analysis of the results revealed no significant differences in the prevalence or magnitude of apical dye penetration between groups.

The Influence of Axial Grooves on Dislodgment Resistance of Prosthetic Metal Crowns in Maxillary Fourth Premolar Teeth of Dogs.

The reported failure rate for full veneer crowns in dogs is suboptimal, particularly in teeth with naturally poor retentive features such as the maxillary fourth premolar tooth of dogs. Although the data regarding crown retention on the maxillary fourth premolar in dogs are limited, there are data that suggest the crown failure rate could be similar to that of the canine tooth. Thus, methods to improve retentive features of the preparation design should be pursued. The objective of the present study is to quantify the influence of axial grooves on the dislodgment resistance of full veneer metal crowns in dogs. Crown dislodgment testing was performed on cast alloy dies of the maxillary fourth premolar tooth with unfavorable retentive features prepared with and without axial grooves, to quantify the difference in force required to dislodge a cemented full veneer crown. The force required to cause crown dislodgment was recorded for each crown. Statistical analysis revealed a significant increase ( P < .001) in the force required for crown dislodgment in teeth prepared with axial grooves compared to those prepared without axial grooves.

The Influence of Axial Grooves on Dislodgment Resistance of Prosthetic Metal Crowns in Canine Teeth of Dogs.

The reported failure rate for full veneer crowns of canine teeth of dogs is suboptimal, particularly in teeth with naturally poor retentive features, such as those with low height/diameter (H/D) ratios or high convergence angles (CAs). The objective of the present study was to evaluate the application of axial grooves in an effort to develop a crown preparation design that enhances the retention of full veneer crowns in dogs. Crown dislodgment testing was performed on cast alloy dies of canine teeth with unfavorable retention features (low H/D and high CA) prepared with (n = 14) and without axial grooves (n = 15) to evaluate the force required to dislodge a cemented full veneer crown. The crown/die units were secured within a universal testing machine and a load was applied at the 45° oblique direction from distal to mesial to replicate the vector encountered during biting-pulling action. The maximum force required to cause crown dislodgment was recorded for each crown. Statistical analysis revealed a significant increase in force required for crown dislodgment when axial grooves were included in the crown preparation design ( P < .001). Crown retention is improved in canine teeth with otherwise poor retention features when axial grooves are made in the labial and palatal/lingual walls during crown preparation.

Case report: Sepsis secondary to infected protracted parotid sialocele after maxillofacial oncologic surgery in a dog.

An 8-year-old male intact mixed breed dog was treated for a 3.7×3×3.6 cm grade 1 multilobular osteochondrosarcoma (MLO) arising from the dorsal aspect of the right coronoid process with a coronoidectomy, a zygomectomy, and a caudal maxillectomy. Ten months later, the dog presented for a swelling near the right angular process, which was presumed to be a locoregional recurrence. Blood work and initial staging tests (abdominal ultrasound) had mild abnormalities of no clinical concern/significance. The dog was hospitalized with a plan for computed tomographic (CT) scan of skull and chest the following day. Overnight, the swelling rapidly increased, and the dog became laterally recumbent, febrile, and hypotensive. Laboratory evaluation revealed hypoglycemia, elevated lactate, and elevated band neutrophils with moderate toxicity, most consistent with sepsis. The dog was stabilized with fluid resuscitation, intravenous (IV) antibiotics, IV dextrose, and pressor support. Once stabilized, a contrast CT scan was performed, which revealed evidence of an infected parotid gland sialocele. To our knowledge, this is the first veterinary case that describes sepsis secondary to an infected protracted parotid sialocele.

Risk stratification scheme based on the TNM staging system for dogs with oral malignant melanoma centered on clinicopathologic presentation.

Introduction: Oral malignant melanoma (OMM) is the most common malignant oral neoplasm in dogs. Tumor recurrence, progression, and regional and distant metastasis remain major obstacles despite advanced therapy. Tumor size has been a consistent, key independent prognostic factor; however, other clinical and histopathologic features impact prognosis and likely influence optimal treatment strategies. Adoption of a risk stratification scheme for canine OMM that stratifies groups of dogs on defined clinicopathologic features may improve reproducible and comparable studies by improving homogeneity within groups of dogs. Moreover, it would aid in the generation of multidisciplinary prospective studies that seek to define optimal treatment paradigms based on defined clinicopathologic features. Methods: To build a platform upon which to develop a risk stratification scheme, we performed a systematic review of clinicopathologic features of OMM, with particular attention to levels of evidence of published research and the quantitative prognostic effect of clinicopathologic features. Results: Tumor size and presence of bone lysis were repeatable features with the highest level of evidence for prognostic effects on survival. Overall, with strict inclusion criteria for paper review, the levels of evidence in support of other, previously proposed risk factors were low. Factors contributing to the challenge of defining clear prognostic features including inconsistencies in staging and reporting of prognostic variables, incomplete clinical outcome data, inhomogeneous treatment, and absence of randomized controlled studies. Discussion: To overcome this in the future, we propose a risk stratification scheme that expands the TNM system to incorporate specific designations that highlight possible prognostic variables. The ability to capture key data simply from an expanded TNM description will aid in future efforts to form strong conclusions regarding prognostic variables and their influence (or lack thereof) on therapeutic decision-making and outcomes.

Kinematic performance of a novel temporomandibular joint replacement prosthesis under bite-force conditions in dogs and cats.

OBJECTIVE: To evaluate the kinematics and stability of the temporomandibular joint (TMJ) of cats and dogs with and without a TMJ replacement (TMJR) prosthesis under simulated bite forces and mouth opening. ANIMALS: Sixteen cadaver skulls from domestic cats (n = 8) and medium- to large-breed dogs (n = 8). METHODS: Intact TMJs were tested. Following condylectomy and coronoidectomy, the skulls were fitted with a TMJR prosthesis unilaterally and retested. Prosthesis was similarly implanted in the contralateral TMJ in 4 cats and 4 dogs before retesting. Left and right bite motions were evaluated before bite contact to peak bite force (200 N in dogs, 63 N in cats). Mouth opening motion was recorded. Mandibular displacement under load was evaluated in 3 orthogonal planes. Maximal displacement was compared between TMJR groups and native TMJ. Prosthesis-bone motion of the temporal and mandibular components was evaluated during simulated bites and mouth opening. RESULTS: TMJR resulted in joint motion not demonstrably different from the native TMJ, with the ability to fully open and close the mouth and with minimal laterotrusion. The TMJR prosthesis demonstrated similar stability after unilateral and bilateral replacement during bite force and with an open mouth. Mean implant-bone motion during bite simulations for the temporal and mandibular TMJR components was ≤ 60 µm in cats and ≤ 30 µm in dogs. CLINICAL RELEVANCE: A novel TMJR can be implanted and allows normal jaw motion. Joint stability is maintained after TMJR implantation in the TMJ of dogs and cats TMJ that is devoid of muscular support.

Clinicial-pathologic correlations of non-trauma related Odontodysplasia in 28 dogs: 2013-2023.

Odontodysplasia is an uncommon dental developmental disorder associated with enamel, dentin, pulp abnormalities, and overall tooth morphology. The affected tooth is grossly abnormal in size and contour and is commonly associated with swelling of the affected area and failure of eruption. Histologically, the enamel and dentin are hypoplastic and hypomineralized. Odontodyplasia occurs most commonly in response to direct trauma to the developing tooth bud (enamel organ and dental follicle). Data on the prevalence and features of non-traumatic odontodysplasia are lacking. Medical records of dogs diagnosed with odontodysplasia were reviewed at the William R. Pritchard Veterinary Medical Teaching Hospital (VMTH), University of California, Davis, for 10 years (from 2013 to 2023). Dogs with a known history of facial trauma, persistent deciduous tooth or teeth over the region of odontodysplastic tooth or teeth, and endodontic disease of the persistent deciduous tooth or teeth were excluded from the study. Twenty-eight dogs were included in this retrospective study, representing an incidence of 1.4 per 100 dogs presenting over 10 years. Regional odontodysplasia (RO) was identified in twenty-two dogs, and generalized odontodysplasia (GO) was found in six dogs. Both comprehensive oral examination and diagnostic imaging were essential in diagnosing and assessing the presence of odontodysplasia. Awake oral examination failed to identify odontodysplasia in almost 70% of the RO cases. Secondary diseases or lesions in odontodysplastic teeth, such as periodontal disease, endodontal disease, and perio-endo lesions, were commonly seen and were particularly more frequently identified in strategic teeth (canine and carnassial teeth) than non-strategic ones. Similarities, such as female predilection, maxilla more commonly affected, and clinical signs, were observed between RO in dogs and those reported in people. The exact etiology of non-traumatic odontodysplasia remains elusive, and the condition may be of multifactorial causality.

Diagnostic yield of dental radiography and digital tomosynthesis for the identification of anatomic structures in cats.

Introduction: Digital tomosynthesis (DT) has emerged as a potential imaging modality for evaluating anatomic structures in veterinary medicine. This study aims to validate the diagnostic yield of DT in identifying predefined anatomic structures in feline cadaver heads, comparing it with conventional intraoral dental radiography (DR). Methods: A total of 16 feline cadaver heads were utilized to evaluate 19 predefined clinically relevant anatomic structures using both DR and DT. A semi-quantitative scoring system was employed to characterize the ability of each imaging method to identify these structures. Results: DT demonstrated a significantly higher diagnostic yield compared to DR for all evaluated anatomic structures. Orthogonal DT imaging identified 13 additional anatomic landmarks compared to a standard 10-view feline set obtained via DR. Moreover, DT achieved statistically significant higher scores for each of these landmarks, indicating improved visualization over DR. Discussion: These findings validate the utility of DT technology in reliably identifying clinically relevant anatomic structures in the cat skull. This validation serves as a foundation for further exploration of DT imaging in detecting dentoalveolar and other maxillofacial bony lesions and pathologies in cats.

Success of orthodontic treatment of linguoverted mandibular canine teeth using a direct inclined plane appliance.

This study evaluated the success rate of orthodontic treatment of linguoverted mandibular canines in dogs using a directly applied inclined plane device. Medical records were retrospectively evaluated at 11 veterinary dental specialty hospitals from 1999 to 2021. Malocclusion classes included 41.7% in class 1, 47.2% in class 2, 6.9% in class 3, and 4.2% in class 4. The severity of linguoversion was mild in 7.6% of teeth, moderate in 33.9%, and severe in 58.5%. There was complete resolution of linguoversion in 71.2% of teeth, functional resolution in 25.4%, and failure in 3.4%. The median treatment time was 42 (11-174) days. Adjuvant orthodontic treatments were performed at the same time as the inclined plane in 45.7% of teeth, including active force orthodontics, extractions of non-strategic teeth, gingivectomy, and odontoplasty. While the inclined plane was in place, 31.4% of dogs required an anesthetized appliance adjustment, and at the time of appliance removal, complications occurred in 19.4% of dogs. Of the teeth that had initial resolution, 14.4% had rebound movement that required additional treatment. This study supports the idea that an acrylic inclined plane is a good treatment option for linguoverted mandibular canines, with a 96.6% success rate within a median of 6 weeks. Yet, orthodontic retention may be necessary in these cases to avoid the need for additional therapies.

Feline chronic gingivostomatitis current concepts in clinical management.

PRACTICAL RELEVANCE: Feline chronic gingivostomatitis (FCGS) is a debilitating disease for cats and a challenge for veterinarians and cat caregivers alike. Recent literature indicates that the disease is immune-mediated in nature and likely associated with a chronic viral infection in patients with higher alpha diversity of their subgingival microbiome. The immune-mediated nature of FCGS includes both local as well as systemic effects, and the transcriptomic analysis of affected patients supports these findings. TREATMENT OPTIONS: Localized therapy in the form of surgical extraction of all, or nearly all, teeth continues to be the mainstay of treatment. For cats that do not respond to surgical management, medical management, in the form of immunosuppressive or immunomodulatory therapy, remains an option. Analgesia is of fundamental importance. Immunomodulation utilizing mesenchymal stromal cell therapy provides an alternative treatment avenue for refractory patients and likely targets the chronic viral infection present in this disease. The potential for treatment stratification and use of novel systemic treatment options may be revealed as the molecular pathways involved in this disease are better described. AIMS: This review outlines current and emerging concepts linking available science pertaining to FCGS and clinical management of the disease. EVIDENCE BASE: The article draws on the best evidence base at this juncture and is also driven by the authors' collective experience of working on the disease for over a decade.

Clinical success of guided tissue regeneration for treating vertical bone and furcation defects in dogs.

This study evaluated the clinical success rate of guided tissue regeneration (GTR) for treating advanced periodontal disease in a large canine cohort. A total of 112 GTR procedures performed from 2003-2021 were retrospectively evaluated, including pre- and post-treatment (3-12 months) periodontal probing depths of 104 treated teeth, dental radiographs of 73 treated teeth, and both diagnostic modalities in 64 treated teeth. Probing depth, radiographically apparent bone height, bone graft material, barrier membrane material, and tooth extraction adjacent to the GTR site were investigated as factors affecting success. Vertical bone defects were evaluated separately from furcation defects. GTR was clinically successful, defined as objective improvement in probing depth, objective decrease in radiographic vertical bone defect, and subjective radiographic gain in bone height in 90.3% of vertical bone defects. Success was significantly associated with the magnitude of initial probing depth and the type of barrier membrane used. GTR was clinically successful, defined as objective improvement in furcation probing and subjective radiographic improvement of the bone in the furcation in 22.2% of furcation defects. When F3 lesions were excluded, GTR was successful in 64.3% of furcation defects. GTR is an appropriate treatment to maintain teeth in the oral cavity of dogs with proper client counseling and patient selection, but it is most likely to be successful in vertical defects.

Evaluation of the efficacy of the Lentulo spiral filler operated at four different speeds and with two different techniques in cadaveric canine teeth of dogs.

This study evaluated the effect of filling technique and rotational speed on the efficacy of sealer cement placement using the Lentulo spiral filler. Cadaveric maxillary and mandibular canine teeth (n = 74) from age and breed matched fresh-frozen adult canine cadaver heads were utilized. Following routine mechano-chemical preparation, teeth were randomly divided into 8 treatment groups with varying rotational speeds [250-2,000 revolutions per minute (RPM)] and fill techniques (backfill technique versus pumping technique). The quality of the sealer cement fill was evaluated radiographically before and after master gutta percha cone placement. Percentage of voids present in the apical, midbody, and coronal portions of the tooth were subjectively scored as: no voids present, voids present in less than 25% of the area, voids present in 25-50% of the area, voids present in greater than 50% of the area. The apex was also scored as underfilled, adequately filled, or overfilled. Operating the Lentulo spiral filler at 2,000 RPM resulted in the best quality fill regardless of filling technique. The pumping technique with placement of the master gutta percha cone had a higher probability of success as compared to the backfill technique, but this finding lacked significance. Regardless of speed or technique, the apical region had the highest quality of fill. The addition of the master gutta percha cone improved the quality of fill. Therefore, we recommend using the Lentulo spiral filler at higher speeds with a pumping technique (followed by addition of a master gutta percha cone) to improve the quality of epoxy resin-based sealer cement placement.

Variation in knowledge, attitude, and practices toward antibiotic use among diplomates of the American Veterinary Dental College: a survey-based study.

OBJECTIVE: To evaluate the knowledge, attitudes, and practices toward antibiotic use among board-certified veterinary dentists. SAMPLE: 104 veterinarians board certified by the American Veterinary Dental College. METHODS: A 30-question survey was generated from an online platform and sent via email listserv to board-certified veterinary dentists. Responses were examined to identify patterns or correlations among the variables of interest. RESULTS: There were 104 board-certified veterinary dentists who responded. The majority reported using prophylactic intraoperative antibiotics sparingly for dental procedures and predominately for patients with historic endocarditis or on immunosuppressive doses of steroids. For healthy patients, they reported that antibiotics are often prescribed during jaw fracture repair, maxillectomy/mandibulectomy, and treatment of stage 4 periodontal disease or periapical lucencies. Knowledge of antibiotic resistance and evidence-based antibiotic use were not significantly different between different practice sectors (academia vs private practice) or dependent on the duration of board certification. Dentists who did not believe antibiotics used postoperatively reduce local postoperative infection rates were less likely to prescribe injectable intraoperative antibiotics for the prevention of postoperative infection. No other variables were associated with the likelihood of prescribing intraoperative antibiotics. More than 95% of veterinary dentists surveyed agreed that specific antibiotic use guidelines for veterinary dentistry would help reduce inappropriate use of antibiotics. CLINICAL RELEVANCE: There are differences among veterinary dentists regarding which procedures and patient-specific comorbidities they believe necessitate the use of prophylactic antibiotics. The development of a consensus statement and prospective studies of current antibiotic use are important next steps to improving antibiotic stewardship in veterinary dentistry.

Contrast-enhanced and indirect computed tomography lymphangiography accurately identifies the cervical lymphocenter at risk for metastasis in pet dogs with spontaneously occurring oral neoplasia.

For dogs with oral tumors, cervical lymph node (LN) metastasis alters treatment and prognosis. It is therefore prudent to make an accurate determination of the clinical presence (cN+ neck) or absence (cN0 neck) of metastasis prior to treatment. Currently, surgical LN extirpation with histopathology is the gold standard for a diagnosis of metastasis. Yet, recommendations to perform elective neck dissection (END) for staging are rare due to morbidity. Sentinel lymph node (SLN) mapping with indirect computed tomography lymphangiography (ICTL) followed by targeted biopsy (SLNB) is an alternative option to END. In this prospective study, SLN mapping followed by bilateral END of all mandibular LNs (MLNs) and medial retropharyngeal LNs (MRLNs) was performed in 39 dogs with spontaneously occurring oral neoplasia. A SLN was identified by ICTL in 38 (97%) dogs. Lymphatic drainage patterns were variable although most often the SLN was identified as a single ipsilateral MLN. In the 13 dogs (33%) with histopathologically confirmed LN metastasis, ICTL correctly identified the draining lymphocentrum in all (100%). Metastasis was confined to the SLN in 11 dogs (85%); 2 dogs (15%) had metastasis beyond the SLN ipsilaterally. Contrast enhanced CT features had good accuracy in predicting metastasis, with short axis measurements less than 10.5 mm most predictive. ICTL imaging features alone were unable to predict metastasis. Cytologic or histopathologic SLN sampling is recommended prior to treatment to inform clinical decision-making. This is the largest study to show potential clinical utility of minimally invasive ICTL for cervical LN evaluation in canine oral tumors.

The diagnostic yield of preoperative screening for oral cancer in dogs over 15 years, part 1: locoregional screening.

OBJECTIVE: Determine locoregional diagnostic yield of 4-site screening (head, neck, chest, and abdomen) to diagnose metastatic disease or clinically significant comorbid diseases in dogs with oral cancer. ANIMALS: 381 dogs with histologically confirmed oral tumors. METHODS: Medical records from 381 dogs with histologically confirmed oral tumors that underwent preoperative screening were retrospectively reviewed. RESULTS: Skull and neck CT scan was performed on 348 patients. Bone lysis was present in 74.4% of tumors. Oral squamous cell carcinoma, sarcomas, and T2-T3 (> 2 cm) tumors had a significantly (P < .05) increased incidence of lysis compared to odontogenic and T1 (< 2 cm) tumors, respectively. Minor incidental findings were present in 60.6% of CT scans. Major incidental findings were found in 4.6% of scans. The risk of diagnosing an incidental finding increased by 10% and 20% per year of age for minor and major findings, respectively. Lymph node metastasis was diagnosed with CT or cytology in 7.5% of cases (10.7% of nonodontogenic tumors, 0% of odontogenic tumors). Oral malignant melanoma, oral squamous cell carcinoma, and T3 tumors had the highest prevalence of metastatic disease at the time of staging. The presence of bone lysis was not associated with cervical metastasis. CLINICAL RELEVANCE: Major incidental findings were rare (< 5%) but primarily included secondary extraoral tumors. Lymphatic metastasis was diagnosed in 10.7% of nonodontogenic tumors, but cytology was not performed in the majority of cases and often included only a single mandibular node. Therefore, these results likely underestimate the incidence of lymphatic metastasis. Guided lymph node sampling is highly recommended, especially for oral malignant melanoma, squamous cell carcinoma, and T2-T3 tumors.