Efficacy and side effects of radiation therapy in comparison with radiation therapy and temozolomide in the treatment of measurable canine malignant melanoma.

Prognosis for unresectable canine malignant melanoma (MM) is typically poor, and therapeutic approaches remain largely palliative. A bi-institutional trial was conducted to compare efficacy and safety of radiation therapy (RT) and RT with post-radiation temozolomide in dogs with chemotherapy-naïve, measurable MM. RT consisted of 5 × 6 Gy fractions over 2.5 weeks. Dogs whose owners wished to pursue chemotherapy received adjuvant oral temozolomide (60 mg m-2 for 5 days every 28 days). Fifteen dogs were treated with RT only (Group 1) and 12 dogs subsequently received temozolomide (Group 2). Overall response rate was similar between Group 1 (86.7%) and Group 2 (81.1%). Median time to progression (TTP) was significantly longer in Group 2 (205 days) compared to Group 1 (110 days; p = 0.046). Survival time was not significantly different between groups. Both treatments were well tolerated. Post-radiation temozolomide has a good safety profile, and may improve TTP in MM when compared to coarse fractionated RT.

Diagnostic value of cytological analysis of tumours and tumour-like lesions of the oral cavity in dogs and cats: a prospective study on 114 cases.

Neoplastic or non-neoplastic masses are common findings in the oral cavity of cats and dogs. The aim of this prospective study was to compare the results of cytological examinations of lesions of the oral cavity following fine-needle aspiration (FNA), fine-needle insertion (FNI), and impression smear (IS) with histopathological results being considered as the diagnostic gold standard. In total, 85 dogs and 29 cats were included in the study. Cases were included when histology and cytology (FNA, FNI, and/or IS) were available from the same lesion; κ-agreement and accuracy between cytological and histopathological results were calculated. Eighteen cytological specimens were excluded, with a retrieval rate of 84.2%. Of the 96 samples analysed, FNA, FNI, and IS were available from 80, 76, and 73 animals, respectively. Overall, 60/67 (89.6%) and 21/29 (72.4%) lesions were neoplastic in dogs and cats, respectively, with the remaining being non-neoplastic. For all lesions, κ-values obtained by FNA, FNI, and IS were in dogs 0.83 (95% confidence interval [CI]: 0.77-0.90), 0.87 (95% CI: 0.81-0.93) and 0.75 (95% CI: 0.67-0.84), respectively, and in cats 0.92 (95% CI: 0.87-0.96), 0.92 (95% CI: 0.88-0.97) and 0.86 (95% CI: 0.79-0.92), respectively. The diagnostic accuracies of FNA, FNI, and IS in dogs with neoplasia were 98.2%, 98.1%, and 91.8%, respectively, and in cats with neoplasia were 95.6%, 95.6% and 95.8%, respectively. In conclusion, the high agreement with histopathology suggests that cytological examinations by FNI, FNA, and IS are all appropriate methods to correctly diagnose lesions of the oral cavity in dogs and cats.

Dental and craniofacial findings in eight miniature schnauzer dogs affected by myotonia congenita: preliminary results.

Myotonia is a clinical sign characterized by the delay of skeletal muscle relaxation following the cessation of a voluntary activity or the termination of an electrical or mechanical stimulus. Recently, Miniature Schnauzers with myotonia congenita associated with defective chloride ion conductance across the skeletal muscle membrane were identified. Congenital myotonia in these dogs appears to follow an autosomal recessive mode of inheritance. Craniofacial and dental findings of eight Miniature Schnauzer dogs with myotonia congenita are described in the present paper. These findings include: delayed dental eruption of both deciduous and permanent dentition: persistent deciduous dentition; unerupted or partially erupted permanent teeth: crowding and rotation of premolar and or incisor teeth: missing teeth: increased interproximal space between the maxillary fourth premolar and first molar teeth: decreased interproximal space between the maxillary canine and lateral incisor teeth: inability to fully close the mouth due to malocclusion: distoclusion: and, decreased mandibular range of motion. A long narrow skull with a flattened zygomatic arch and greater mandibular body curvature were also consistent findings in the affected dogs. The small number of dogs studied prevents conclusive statements about the origin of these abnormalities, however it is interesting that only 1 of 45 unaffected Miniature Schnauzer dogs showed similar traits.

Radiographic study of the maxillary canine tooth of four mesaticephalic cats.

The radiopaque and radiolucent anatomical structures that are superimposed over the root of the maxillary canine tooth in mesaticephalic cats were identified on digital radiographs made at various angles. The vomer bone, the nasal bone, the palatine fissure, and the infraorbital foramen were not superimposed over the root of the canine tooth in the range of angles examined. Superimposition with the palatine sulcus (which is rarely visible clinically because of silhouetting of the soft tissues) only occurred at extreme horizontal (cross-sectional arc) angles. The second premolar tooth was superimposed at a cross-sectional angle of 80 degrees and 90 degrees. The structures of concern in the interpretation of radiographs of the maxillary canine tooth in mesaticephalic cats are the conchal crest, the line of conjunction between the vertical body of the maxilla and its palatine process, the incisivomaxillary canal (which is rarely visible on radiographic images), and the lachrymal canal. Because of their anatomical vicinity, the radiographic position of these structures relative to the maxillary canine tooth can only be minimally changed. It was not possible to identify an "ideal" angle to radiograph the maxillary canine tooth in these four mesaticephalic cats. However, an acceptable compromise between minimal distortion of the image and satisfactory visualization of the root was obtained with the radiographic beam (rostro-caudal rotation) angled at 80 degrees and the skull (rotation in cross-sectional arc) angled at 70 degrees.

Treatment of traumatic dental displacement in dogs: six cases of lateral luxation.

In dogs and cats, the most common causes of dental injury are fights with other animals, car accidents, falls from a height, and chewing on hard materials such as bones or rocks. The trauma more often causes fracture of the teeth, but sometimes avulsion or luxation can occur. Avulsion is the complete displacement of the tooth out of the alveolar socket and luxation is the partial displacement of the tooth. Tooth luxation and avulsion represent dental emergencies. Time is an important factor for successful treatment; the prognosis becomes poorer the longer the tooth is out of the socket. This paper describes the guidelines for treatment of dental displacement in cats and dogs and presents six cases of dental lateral luxation in dogs seen at the Veterinary Hospital of the University of Pennsylvania (VHUP) in the period from May 1996 to September 1997.

Radiographic study of the maxillary canine tooth in mesaticephalic dogs.

Radiology is the most important diagnostic technique for evaluation of the radicular structure of the tooth and adjacent areas. However, superimposition of other oral or nasal structures often creates difficulties when interpreting radiographic images. The purpose of this study was to identify and locate any anatomical structures that may be superimposed over the root of the maxillary canine tooth in radiographs of dogs. Results showed that the nasal conchae minimally interfere with the visualization of the tooth. The vomer bone and maxillary structures (the conchal crest, the line of conjunction between the maxillary body and the palatine process, and the palatine sulcus) are visible as linear radiopacities, and were found to be responsible for most of the radiographic features in this area. The incisivomaxillary canal and the palatine fissure caused radiolucent images. The incisivomaxillary suture and the nasoincisive suture may appear as radiolucent images in young skulls and linear radiopacities in older skulls. It appears from this study that a compromise between minimal superimposition of dental and non-dental structures and small image distortion is needed to obtain diagnostic radiographic views of the maxillary canine tooth in mesaticephalic dogs. The relative positions of the conchal crest, the line of conjunction between the vertical body of the maxilla and its palatine process, the incisivomaxillary canal, and the tooth, cannot be changed radiographically because of the close anatomic position of these structures.