Rhabdomyosarcoma is an aggressive neoplasm of primitive mesenchymal cells that have the potential to differentiate into skeletal muscle. Case selection required positive expression of both vimentin and desmin, confirmed by immunohistochemistry, and negative expression of cytokeratin. In this study of 34 young dogs, the average age at time of diagnosis was 16.5 months. The majority of tumors were located in the maxilla (n = 26, 76%), whereas a smaller subset (n = 4, 11%) occurred solely within the mandible. One (2.9%) involved the caudal mandible and maxilla, 1 of 34 (2.9%) involved the maxilla and palate, and 2 of 34 (5.8%) exclusively involved the soft palate. Of the maxillary tumors, 16 (59.2%) involved the nasal cavity. Thirty-one (91%) presented to their primary care veterinarian for acute facial swelling, with 17 (50%) cases also reporting concerns for ocular disease. Radiographically, 29 (87.8%) showed evidence of cortical lysis and loss of lamina dura surrounding the roots of teeth associated with the tumors. Histologically, neoplastic cells were small, round to spindle, and rarely had morphological features of myofiber differentiation. Radiographic findings consistent with metastasis to the lungs and/or lymph nodes were reported in 5 cases via thoracic imaging. Regional lymphadenopathy was identified in 19 (55%) cases, with metastasis cytologically confirmed in 2 patients. All 30 (100%) patients with follow-up data were euthanized due to progression of local or metastatic disease. The mean survival time was 59 days. Canine oral rhabdomyosarcomas are aggressive neoplasms that occur in young dogs and carry a poor prognosis.
Class II malocclusion in dogs is a skeletal abnormality characterized by mandibular distoclusion that can result in traumatic occlusion and compromised oral health. While associated soft tissue trauma is well recognized, the prevalence of concurrent congenital and developmental dental anomalies in affected dogs has not been systematically evaluated. The aim of this study was to determine the prevalence of dental anomalies in dogs with class II malocclusion and compare findings to dogs with normal occlusion. Medical records from three veterinary dentistry referral centers were retrospectively reviewed. Dogs with class II malocclusion were included if they had complete oral examinations, dental charting, and full-mouth diagnostic imaging. Control dogs met the same criteria. Dental anomalies were recorded, and multivariable generalized linear models were used to compare prevalence between groups while adjusting for age, sex, and body weight (p < .05). Eighty-seven dogs with class II malocclusion and 98 controls were included. Affected dogs had a significantly higher prevalence of dental crowding, persistent deciduous teeth, and rotated teeth. Other anomalies-including supernumerary teeth, hypodontia, infraeruption, enamel defects, dilaceration, fused roots, gemination, and impacted teeth-were observed but did not differ significantly between groups. Dogs with class II malocclusion are more likely to exhibit multiple dental anomalies compared to dogs with normal occlusion. These findings suggest overlapping developmental mechanisms affecting craniofacial growth and odontogenesis. Early recognition is important for timely intervention and improved patient welfare.
While the gross dental anatomy of the Virginia opossum ( Didelphis virginiana ) has been described, the radiographic appearance of the dentition and the prevalence of dental and oral pathology have not been comprehensively evaluated. The objective of this study was to characterize the intraoral radiographic dental anatomy of the Virginia opossum and to determine the prevalence and distribution of anatomic variations and pathologic conditions affecting the dentition. Oral examination, standardized photography, and full-mouth intraoral dental radiography were performed on 25 deceased free-ranging opossums obtained from a wildlife rehabilitation hospital. Findings were systematically recorded, including the presence of developmental variations, malocclusion, periodontitis, endodontic disease, and tooth resorption. Dental anatomical or developmental variations were identified in 76% of specimens, with missing teeth being the most frequent finding. Supernumerary teeth were uncommon at 8% of specimens and restricted to the mandibular first premolars. Root morphology variations were frequently observed, including convergent premolar roots in 44% of adult specimens and mandibular root dilaceration in 20%. Class III malocclusion with dental attrition occurred in 16% of specimens. Endodontic disease affected 80% of opossums. Apical obliteration of the canine pulp canal was identified in 76% of adult canine teeth and likely represents a species or age-related variation. Dental fractures were common, particularly in canine teeth, at 80%. Periodontitis was identified in 24% of opossums, primarily affecting molars. These findings establish baseline radiographic anatomy and disease prevalence to support diagnosis and treatment planning in wildlife and veterinary care.
In active force orthodontics in dogs, the ratio of root surface area (RSA) between the anchorage and target dentition is the primary factor when determining the expected relative movement patterns. Reinforced anchorage involves bonding of adjacent structures together (ie, 2 or more teeth) in the anchorage unit to increase the total attachment or RSAs. This methodology is commonly implemented in the movement of the maxillary canine tooth using active force orthodontics by bonding the maxillary fourth premolar and first molar teeth together. Cone beam computed tomography scans of mesaticephalic dogs were evaluated using third-party viewing software to determine the RSAs of the maxillary canine, fourth premolar, and first molar teeth. The RSA ratios were then calculated for the following comparisons: canine to fourth premolar (C:PM4), canine to first molar (C:M1), and canine to combined fourth premolar and first molar (C:PM4 + M1). Forty-eight dogs and 86 dental arcades met the inclusion parameters. 20.93% of dental arcades had a C:PM4 RSA ratio <1, none of the dental arcades had a C:M1 RSA ratio <1, and all but one arcade (98.81%) had a C:PM4 + M1 RSA ratio <1. Increased weight was significantly correlated with an increase in all RSA ratios. Based on these findings, the authors recommend continuing the practice of bonding the maxillary fourth premolar and first molar teeth together when applying active force orthodontics for the maxillary canine tooth in mesaticephalic patients.
Oral squamous cell carcinomas (OSCCs) are commonly diagnosed in animals, particularly African pygmy hedgehogs ( Atelerix albiventris ) (APHs). This study reviews individual hedgehog and tumor characteristics of 17 OSCCs in APHs, as well as 94 OSCC cases currently recorded in the scientific literature, to assess common trends and potential risk factors for these neoplasms in the species. A single detailed case of OSCC is described in the case series; it was submitted for autopsy with cytological and diagnostic imaging data while the remaining cases were routine histological biopsies. Histologically, OSCCs showed infiltrative trabeculae and nests of squamous epithelial cells with variable degrees of keratinization. Bone and nasal invasion were observed in some OSCCs ( n = 3), consistent with the literature. Metastasis has been rarely reported and was not recorded in this case series. Inflammation was observed in examined OSCCs, as well as in literature cases, including in the mucosa adjacent to OSCCs, suggesting a potential role of chronic inflammation in tumor promotion. This study highlights that individuals older than 2 years old with chronic stomatitis are potentially at higher risk of developing OSCCs, with the maxilla (66.0%) being the most common site of tumor development. No sex predilection is evident. Recurrence and metastatic potential remain insufficiently documented, warranting further investigation.
The purpose of this retrospective study was to determine the prevalence of nonvital incisor teeth in small breed dogs. Intraoral maxillary and mandibular radiographs of the incisor teeth obtained between January 1, 2017 and December 31, 2021 in 287 dogs previously diagnosed as having nonvital teeth and weighing <10 kg were reviewed. A total of 2682 incisor teeth were assessed and were diagnosed as nonvital if one of the following radiographic criteria was met: widened pulp canal; widened apical periodontal ligament space; periapical radiolucency; internal root resorption; external root resorption; and changes in the trabecular bone pattern around the root apex. Of the 287 dogs, 74 (25.8%) had only 1 nonvital incisor and 57 (19.9%) had 2 or more nonvital incisors. Two hundred fifty out of 2682 incisors (9.3%) evaluated were nonvital, with the maxillary incisors being 2.1 times more likely to be nonvital (95% CI [1.6-2.9]) compared to mandibular incisors. While both periodontitis ( P = .002) and class 3 malocclusion ( P = .02) significantly increased the likelihood of nonvital incisors as well, age, sex, and body weight had no significant impact. Diagnosis and treatment of nonvital teeth in the dog are important, because if these are left untreated, infection and pain may ensue. The results reported here will assist veterinarians in providing optimal therapy for dogs with nonvital incisors by increasing the index of suspicion and facilitating earlier diagnosis in animals at increased risk.
Rostral maxillary defects following curative intent surgery for maxillary neoplasms can be difficult to close. This paper describes a modified T-shaped closure following rostral maxillectomy that permits the primary mucosal closure of larger rostral maxillary defects that may not be amenable to standard closure techniques. The technique facilitates decreased incision site tension, results in a more cosmetic closure (decreased concave deformity of the muzzle), maintains normal vestibule size, preserves critical vasculature, and maintains the greatest amount of available tissue for repair of defects, should they occur. Retrospective evaluation of medical records from January 1, 2015, through January 31, 2023, at the Center for Veterinary Dentistry and Oral Surgery, Gaithersburg, MD, United States, identified 23 dogs having undergone bilateral incisivectomy and unilateral or bilateral rostral maxillectomy where this closure was utilized. Evaluation of available medical records and client interviews demonstrated successful outcomes; however, further studies are needed to validate the success rate of this technique.
Vital pulp therapy (VPT) is a dental procedure aimed at preserving tooth vitality after pulp exposure by removing part of the exposed coronal pulp and placing a protective pulp dressing material directly over the remaining pulp, followed by a tightly sealed restoration to prevent bacterial leakage at the restoration-dentin interface. Indications include recent complicated crown fracture (CCF) or traumatic malocclusion in mature, as well as immature, permanent teeth. This retrospective study evaluated the outcome of 47 teeth in 36 cats treated with VPT at a referral clinic between 2009 and 2025, using either dental radiography, cone beam computed tomography (CBCT) or both modalities. The overall success rate was 81%, supporting VPT as a viable alternative to extraction or root canal therapy in feline teeth with recent CCF or traumatic malocclusion. Although not statistically significant, teeth with CCF and associated contaminated pulps exhibited higher failure rates than teeth in traumatic malocclusion, which were cases that had crown height reduction performed in a more sterile environment, and which had uncontaminated pulp at the time of VPT. Mineral trioxide aggregate was used as the pulp capping material in all cases. Limitations include the retrospective design, limited sample size, and large variation in time from VPT to follow-up. Results emphasize the clinical benefit of VPT in cats, while highlighting the importance of case selection, sufficient follow-up, and further prospective research to optimize protocols and long-term outcomes.
A 6-year-old neutered male feline patient was presented with left sided facial swelling. A diagnosis of benign hypertrophy of the masseter and pterygoid muscles was made based on clinical, imaging, and histopathologic findings. Benign hypertrophy of masticatory muscles is an uncommon condition described in the human literature. Masseter muscle hypertrophy has been diagnosed rarely in humans with few references reporting concurrent hypertrophy of the medial and lateral pterygoid muscles. The primary inciting cause of this condition is unknown. Treatment in humans is primarily sought for cosmetic reasons with multiple treatment modalities being described including medical and surgical management. This article describes the first reported case of benign masseter and pterygoid muscle hypertrophy in the veterinary literature.
The prevalence of periodontal and dental pathology in a random canine population has not been established by a single prospective clinical evaluation using defined and accepted diagnostic criteria. A prospective anesthetized visual examination and periodontal probing, without imaging, of the canine dentition in a random dog population (369 dogs) was performed. Oral examination and periodontal probing using the American Veterinary Dental College periodontal staging criteria for clinical attachment loss and diagnosis of periodontal disease was used. Periodontal disease stages (PD)1-4 were identified in 98.6% (PD stage 1, 39% and PD stages 2-4, 59.6%) of the dogs. Periodontal disease was significantly associated with skull conformation, body weight, and age. One or more fractured teeth were found in 50.9% of the patients. Mesaticephalic skull conformations had a greater number of tooth fractures compared to brachycephalic and dolichocephalic skull conformations. There were a greater number of fractured teeth with increasing age and body weight. There were a greater number of missing teeth as patient body weight decreased. This study confirmed the prevalence of periodontal disease to be 98.6% (PD1-PD4) in dogs greater than 1 year of age in a random anesthetized dog population based on periodontal examination without radiographic assessment.
Halitosis, or oral malodor, is caused by unwanted oral microbes that metabolize proteins and produce volatile sulfur compounds (VSCs). These malodorous VSCs may negatively impact oral health as they are pro-inflammatory, and halitosis is generally considered an important marker of oral health status. A previous clinical study with 24 dogs showed that daily administration of 250 mg of a novel canine oral health postbiotic (COHP) significantly decreased VSCs by 26% compared to placebo on Day 14, with twice as many dogs showing perceptibly improved breath in the COHP group on Day 7. The present double-blinded, placebo-controlled validation study evaluated COHP's ability to reduce canine oral malodor at a reduced dose of 150 mg to confirm that the previously reported efficacy of COHP is reproducible and maintained at a lower dose. Twenty-four dogs were stratified by starting VSC levels and received either COHP or placebo as a powder topper over standard chow for 14 days. VSC levels were measured via a halimeter, and perceived malodor was assessed using a 10-point scale on Days 0, 7, and 14. VSC levels increased in the placebo group by 24% on Day 7 (P = .006) and 38% on Day 14 (P = .002), while COHP prevented VSC increases on both days, resulting in a -26% change compared to placebo on Day 14 (P = .04). VSC levels correlated with perceived malodor, and COHP trended toward a 1-point reduction in perceived malodor compared to placebo (P = .06). These findings agree with the previous study, suggesting COHP effectively reduces canine halitosis across 2 doses.
Parosteal osteosarcoma (OSA) is a subtype of surface OSA that is considered slow growing with a less aggressive biological behavior compared to central OSA and, therefore, carries a better prognosis with surgical excision. Parosteal OSA has a predilection for the skull in dogs with documented more frequent occurrences on the zygoma, maxilla, or coronoid process of the mandible, all of which present unique challenges to the oral surgeon. Ten cases of parosteal OSA of the canine maxillofacial bones are summarized and discussed in this report. The most common bone of origin was the caudal maxilla and/or zygoma in 50% of tumors. Exophthalmos was a prominent clinical sign noted in 40% of dogs. Median survival time was 14 months, with a one-year survival rate of 60%. Metastasis to the lungs was suspected in three cases. The histopathological diagnosis of parosteal OSA is crucially dependent on diagnostic imaging. When a primary bone tumor of the maxillofacial bones is suspected, it is essential for the oral surgeon and pathologist to collaborate to provide informed guidance on surgical planning, anticipated long-term outcomes, and clinical monitoring for these patients. The goals of this retrospective study are to identify key clinical and radiographic features, improve recognition for accurate diagnosis, and establish treatment recommendations for canine maxillofacial parosteal OSA.
The present study aimed to investigate the anatomical, ultrasonographic, radiographic and computed tomographic parameters of the normal temporomandibular joint (TMJ) and related structures in dogs. Ten clinically healthy adult mesocephalic dogs (8 live and 2 cadavers), aged 2 to 4 years, were included in this study. Gross anatomical dissection was performed in 2 cadaveric dogs to validate the ultrasonographic features of the TMJ. Radiography provided visualization of bony structures of the TMJ, but images were superimposed on surrounding structures. Computed tomography produced excellent and in-detail bony anatomy. Ultrasonography demonstrated superior soft tissue resolution, and visibility of the intra-articular soft structures of the TMJ and its neighboring soft tissues, such as the masseter muscle, parotid gland, and articular capsule. Gross anatomical dissection validated the ultrasound findings. This study concluded that ultrasonography is a practical, noninvasive diagnostic tool for the assessment of normal TMJ in dogs.
The oral microbiome is an important aspect of overall oral health in dogs. To investigate the ability of a postbiotic, canine oral health postbiotic (COHP), to support oral health, a double-blind, placebo-controlled study was conducted with a dirty tooth model to assess its ability to reduce volatile sulfur compound (VSC) producing microbes that cause halitosis and modulate canine oral microbiome composition. Ten client-owned dogs were randomly split into 2 groups. The groups received either the COHP or a placebo as a powder topper on food for 7 days. Oral microbiome samples were collected on day 0 and day 7 along with the buccal gingival margin. Hydrogen sulfide (H2S)-producing colonies were quantified by plating the oral microbiome samples and counting pigment-producing colonies. Additionally, oral microbiome samples were sequenced, and taxa abundance was quantified. A trend toward a reduction in H2S-producing colonies was observed in the COHP group (P = .06), but not in the placebo group (P = .9). Canine oral health postbiotic reduced the abundance of 9 times as many taxa as the placebo, including taxa that form biofilms and produce VSCs. The placebo reduced the abundance of only one taxon, which is not associated with biofilms or VSCs. The findings provide evidence for COHP's ability to promote a positive shift in the canine oral microbiome, and, together with previous results, provides evidence that it may broadly help to maintain canine oral health.
A 3-year-old neutered male domestic shorthair cat was presented with acute pain during feeding and with hypersalivation, without any history of trauma. Oral examination revealed a lateral deviation of the left mandible and a soft, painful swelling at the site of the missing left mandibular canine tooth (304). Intraoral radiographs and computed tomography (CT) demonstrated extensive bone lysis of the left mandible and a cystic lesion extending from the mandibular symphysis to the level of the mandibular fourth premolar tooth (308), within which the embedded canine tooth was located. Regional lymph nodes appeared normal on clinical and CT examination, and fine-needle aspiration of the left mandibular node showed reactive changes. A left-sided segmental mandibulectomy, from the mandibular symphysis to the mandibular first molar tooth (309), was performed to remove the cyst and the affected bone. Histopathological evaluation identified features consistent with an odontogenic keratocyst and concurrently confirmed the presence of a rhabdomyosarcoma. Three months after surgery, the cat was presented with a rapidly enlarging mass firmly attached to the soft tissues of the mandibulectomy site and it was euthanized a few days later. This case represents the first reported coexistence of an odontogenic keratocyst with a malignant neoplasm, specifically rhabdomyosarcoma, in a cat. The findings highlight the importance of thorough investigation of cystic oral lesions, as they may be associated with severe bone destruction and concurrent malignancy, even in young animals.
A variety of factors which might potentially affect the severity score of rabbits' teeth were investigated. These included the age, breed and gender of the animal as well as its cephalic index and dietary factors such as type of bowl feed and availability of hay or fresh grass. Age and cephalic index values were found to be significantly associated with the severity of dental disease, but the rabbit's gender and breed did not significantly affect this. The type of bowl feed also had an effect. However, the frequency of access to hay, fresh grass or grazing did not significantly affect this score suggesting that although some form of grass is important in the diet, the form of grass supplied to animals is not likely to affect severity scores.
Porcupine quill injuries have been reported in the veterinary literature as the source of a wide range of complications affecting separate body regions and organ systems, particularly in dogs from specific geographic locations. However, migration of porcupine quills involving the temporomandibular joint and its clinical consequences have not been previously reported. This report describes the first documented case of a dog presenting with trismus and a draining tract in the area of the left zygomatic arch several weeks following a porcupine encounter. The dog was referred as a consequence of the unsuccessful initial management of the injuries and the associated clinical signs. For this reason, advanced diagnostic imaging, including ultrasonography and computed tomography, was performed to investigate the possible cause. Surgical management for resolution of the clinical signs involved resection of the zygomatic arch, followed by partial resection of the lateral aspect of the mandibular condylar process for retrieval of the quill fragments.
