Anatomical and Computed Tomography Study of the Mandible of the Patagonian Huemul (Hippocamelus bisulcus): Ecological and Clinical Insights.

Given the high prevalence of skeletal and mandibular diseases in the Patagonian Huemul, comprehensive anatomical studies are essential to understand the impact of nutritional deficiencies and support conservation efforts. The aim of this study is to provide a detailed anatomical characterisation of three exhumed mandibles of Patagonian huemul (Hippocamelus bisulcus) through three-dimensional reconstructions obtained from computed tomography data and semi-automatic segmentation, documenting their distinctive features. The findings revealed distinctive features in the mandible, consistent with the browsing habits of herbivores, such as a robust coronoid process, a wide and deep pterygoid fossa, a significantly lower mandibular condyle compared to other deer species and a unique configuration of the mandibular canal with a curved caudal portion and a straight rostral portion. These anatomical adaptations are likely related to the species' feeding habits and behaviour. The study also addressed the challenges of researching an endangered species, given that access to biological material is restricted by strict regulations in Chile and Argentina. These restrictions limited the available sample size and hindered the acquisition of additional specimens, which could affect the generalisation of the results. Despite these limitations, the research provides valuable anatomical insights that are fundamental for the biology, clinical practice and management of specimens. In conclusion, the mandibles of both juvenile and adult Patagonian huemul demonstrate distinctive features characteristic of browsing herbivores. The findings can serve as a basis for future comparative studies on mandibular anatomy and function in this endangered deer species as well as in other herbivorous deer.

Radiologic and computed tomography evaluation of the beaks from three bird species.

This study aimed to evaluate the beaks of three species of birds using radiography and computed tomography (CT). The mean lengths of maxillary and mandibular rostra on radiographs were highest for toco toucan, followed by buff-necked ibis, and least for red-legged seriema birds. The height and width of maxillary and mandibular rostra measured on CT had mean values highest for toco toucans, followed by red-legged seriema, and least for buff-necked ibis. Except for the proximal region of the maxillary rostrum, the HU values were positive for other regions of the maxillary and mandibular rostra in the buff-necked ibis and red-legged seriema and negative in all for the toco toucan.

Combined use of body condition score, radiography, ultrasonography and computed tomography in body condition evaluation of crab-eating fox (Cerdocyon thous).

This study aimed to evaluate the application of radiography, ultrasonography, and computed tomography (CT) as auxiliaries in the determination of body fat and musculature in crab-eating foxes (Cerdocyon thous). Eight animals were evaluated and classified based on the body condition score (BCS) scale. The total cut volume, total visceral volume, total subcutaneous volume, visceral fat volume, subcutaneous fat volume, and total fat volume were measured. The correlation of the BCS with the other data was determined. In the ultrasound, there was a correlation of the vertebral epaxial musculature score (VEMS) with body weight, BCS, muscle mass score (MMS), animal's height, and height at the withers. In the radiographic analysis, the amount of subcutaneous fat obtained in L3 vertebrae did not present a significant correlation with BCS, as opposed to L6. In the tomographic analysis, TFV/L6, VFV/L6, and SFV/L6 correlated with BCS in L3, and only SFV /L6 in L6. When the ratios between fat volumes were correlated, the correlation with BCS occurred only in L6 in the TFV/TBV, SFV/SVC, and VFW variants. Radiography and CT were effective and had a good association with BCS. With the CT it was possible to demonstrate the distribution of total fat at the level of the L3 slice. The ratio of calculations considering the length of the L6 vertebra was more adequate, while at the level of L6 the ratio between the volumes of the compartments was more effective.

Morphology and computed tomography of the larynx in the white-eared opossum (Didelphis albiventris).

The white-eared opossum (Didelphis albiventris) is a Neotropical marsupial that occurs in the Brazilian territory. The larynx is an important organ of vocalization in mammals, although, other laryngeal functions are more fundamental for survival of mammals than phonation. The anatomical knowledge of respiratory structures is pivotal for a better understanding of the species. Thus, this study aimed to examine the larynx of the white-eared opossum by gross anatomy, computed tomography and histological description. For this, 10 adult (six females and four males) white-eared opossums (D. albiventris) were used. The white-eared opossum larynx was formed by epiglottis, thyroid, cricoids and arytenoid cartilages and a corniculate process. There is a similarity between the larynx of this marsupial and those reported in other wild mammals, regarding the number of cartilages and their location. Histologically, the epiglottis consisted of elastic cartilage and thyroid, cricoid and arytenoid cartilages were composed of hyaline cartilage. The epiglottis protruded rostrally into the nasal part of the pharynx, above the soft palate, and this is probably a marsupial characteristic as the fact that the thyroid and cricoid cartilages were ventrally fused. The hyoid apparatus was similar to that of other animals, with the same bony constitution, but with a greatly reduced stylohyoid bone. Histologically, the larynx was similar to those of other species such as koala, armadillo, crab-eating foxes and giant anteaters. The knowledge of the larynx morphology is important for the anatomical features of the species and clinical and surgical procedures, such as endotracheal intubation.

Tomographic evaluation of the glands and lymph nodes of the cervical region in the crab-eating fox (Cerdocyon thous).

The present study aimed to determine references of normality of computed tomographic (CT) images of mandibular and parotid salivary glands (PSGs), medial retropharyngeal and mandibular lymph nodes and thyroid gland of 10 clinically healthy crab-eating foxes, Cerdocyon thous. The location, shape, homogeneity of the parenchyma, and length, height, width and pre- and post-contrast attenuation values were evaluated. The anatomical structures in the crab-eating foxes studied here presented anatomical landmarks similar to those described for domestic dogs, and showed a regular shape and homogenous parenchyma, except for the PSGs, that showed predominantly heterogeneous parenchyma. The thyroid gland topography in the crab-eating fox, though very similar, is not identical to the domestic dog and the presence of isthmus between the lobes was not detected. The values obtained from crab-eating foxes are within the normal range, although in the upper limits of dogs. There was a significant difference in the attenuation values between the right and left lobes of the thyroid gland, being greater in the left thyroid lobe. CT attenuation values ranges for this neotropical canid can be incorporated into routine staging procedures in the veterinary care of the crab-eating foxes. Furthermore, the CT images obtained were similar to those of healthy dogs, and the information obtained can be considered as initial tomographic references of normality in the cervical structures of the crab-eating fox, in order to aid in the diagnosis of future diseases that can affect this neotropical canid.

Brain volumetry from CT-scan endocasts of three neotropical carnivores.

Studies on brain anatomy can clarify specific evolutionary and behavioural aspects of wild animals. The rich diversity in a broad range of habitats makes carnivorans especially eligible for studying the relations between the brain form and behaviour, cognitive, sensorial and motor traits. This study compared the brain's contour and total and segmented brain volumetry in three species of neotropical carnivorans. CT images of 17 skulls of three species were acquired: Conepatus chinga (n = 6), Galictis cuja (n = 6) and Lontra longicaudis (n = 5). Three-dimensional endocasts allowed for estimating the brain's total and segmented volumes (olfactory bulb, rostral cerebrum, caudal cerebrum and cerebellum/brain stem). The average volume percentage of the segments was compared interspecifically and intraspecifically between the sexes. The otter has a notably more complex gyrification, typical for semiaquatic carnivorans. Proportionally, the olfactory bulb was significantly larger in hog-nosed skunks, possibly due to a better sense of smell for capturing insects. The proportional volumes of the rostral cerebrum, caudal cerebrum and cerebellum/brain stem segments did not differ between these species. Social behaviour traits and tactile, motor and balance skills were probably not sufficiently distinct to reflect differences in the brain segments analysed in these three species.

Computed tomography angiography aids in predicting resectability of isolated liver tumors in dogs.

OBJECTIVE: To assess the accuracy of CT angiography (CTA) in predicting resectability, degree of surgical difficulty, and individual factors that may impact resectability of isolated hepatic masses in dogs. ANIMALS: Prospective study of 20 dogs with 21 isolated hepatic masses. PROCEDURES: All CTAs and surgeries were performed between June 16, 2013, and November 30, 2016, at The Animal Medical Center in New York. Preoperative CTA images were evaluated by a board-certified surgeon (n = 2). A preoperative assessment was completed, documenting several predetermined factors aimed at predicting resectability of each mass and the degree of surgical difficulty. Resectability was divided into gross resectability and complete histologic excision. Following surgery, the surgeon completed a postoperative assessment documenting the intraoperative findings. Independently, a blinded board-certified radiologist analyzed the images and completed an identical preoperative assessment. RESULTS: The radiologist was more accurate in lesion localization compared to the surgeon (P = .023). Seventeen (17/21) masses were grossly resectable in surgery. Two additional (2/21) masses that were deemed grossly resectable were incompletely excised on histopathologic analysis. Both the surgeon and radiologist were accurate in their prediction of gross resectability and complete excision. Major vascular involvement, multilobar involvement, and right-sided laterality negatively affected resectability. The surgeon was significantly more accurate in predicting the degree of surgical difficulty (κ = 0.50) when compared to the radiologist (κ = 0.38). CLINICAL RELEVANCE: Preoperative CTA of isolated hepatic masses is useful in prediction of surgical difficulty and resectability, as well as identifying several factors that impact resectability.

Giant and potentially malignant bullae in a dog.

Background: Primary lung neoplasms are, frequently represented by solid, solitary, or multiple formations. However, malignant cavitary lesions may be presented as lung adenocarcinomas. Those malignant lesions differ from benignant bullae by the thickness heterogeneity of its surrounding shape. Case Description: The present clinical case reports a 14-year-old female dog, of mixed breed, with an increase in the coughs frequency, fatigue, and exercise intolerance. A chest X-ray was taken, a large emphysematous cystic area was found, with thickened and irregular walls located in the left caudal pulmonary lobe, which measured 8 × 7.5 × 3 cm, and rejected the bronchial branch corresponding to the left caudal pulmonary lobe, in addition to thickening of the bronchial walls, compatible with bronchopathy. The tomographic examination of the cavity showed an air content structure, oval to round in shape, with irregular thick hyperattenuating walls measuring approximately 0.4 cm in thickness, occupying more than 30% of the left hemithorax, and pulmonary lobectomy was chosen. Histopathology confirmed the diagnosis of bronchoalveolar adenocarcinoma, with the presence of sparse areas of necrosis and dystrophic calcification. Conclusion: The present case successfully diagnosed a malignant bulae, after a surgical remove. The tomographic finds although not confirmatory, suggest a malignant component by the shape and thickness of its wall. The tomographic exam is of great importance, because only through it, it is possible to evaluate if there is lymph node or pleural involvement or the presence of small metastasis foci. There is indication for surgery and histopathological examination of the piece for a definitive diagnosis.

Relation of fibrocartilaginous embolism and acute and non-compressive nucleus pulposus extrusion with imaging tests: case report / Relação de embolia fibrocartilaginosa e extrusão aguda e não-compressiva do núcleo pulposus com testes de imagem: relato de caso

Fibrocartilaginous embolism (FCEM) and acute, non-compressive nucleus pulposus extrusion (ANNPE) are non-compressive myelopathies that are difficult to differentiate. The definitive diagnosis is obtained only with histology, but the presumptive diagnosis is made through clinical signs and imaging tests. The aim of this study is to report the imaging tests performed for the diagnosis of a neurological clinical case and discuss the best diagnostic method. After attending the patient, complementary tests were requested. Radiography results showed no change. The computed tomography diagnostic impression indicated distal protrusion between C6-C7, T11-T12, T13-L1 followed by mild spinal cord compression defined by the presence of a ventral hyperattenuating region. Magnetic resonance (RMI), showed a slight T2W hypersignal, well delimited in the gray matter, lateralized to the right, over the cranial third of C7. Concluding that the magnetic resonance is the method that brought more information for the diagnosis, in which the others were not described medullary alterations pertinent to FCEM and ANNPE. With their fair prognosis, the absence of histological diagnosis of these diseases may be a limiting factor in this study and, in relation to the RMI alterations being very similar between FCEM and ANNPE it is not possible to diagnose fully accurately.

A embolia fibrocartilaginosa (EFC) e a extrusão aguda não compressiva do núcleo pulposo (EANCNP) são mielopatias não compressivas de difícil diferenciação. O diagnóstico definitivo é obtido apenas com a histologia, mas o diagnóstico presuntivo é feito por meio de sinais clínicos e exames de imagem. O objetivo deste trabalho é relatar os exames de imagem realizados para o diagnóstico de um caso clínico neurológico e discutir o melhor método diagnóstico. Após o atendimento do paciente, foram solicitados exames complementares. Os resultados da radiografia não mostraram nenhuma alteração. A impressão diagnóstica da tomografia computadorizada indicou protrusão distal entre C6-C7, T11-T12, T13-L1, seguida de leve compressão medular definida pela presença de região hiperatenuante ventral. À ressonância magnética (RM), apresentava discreto hipersinal em T2W, bem delimitado na substância cinzenta, lateralizado à direita, sobre o terço cranial de C7. Concluiu-se que a ressonância magnética é o método que mais trouxe informações para o diagnóstico, os demais métodos não foram descritos alterações medulares pertinentes à EFC e à EANCNP. Com seu prognóstico favorável, a ausência de diagnóstico histológico dessas doenças pode ser um fator limitante neste estudo. Em relação às alterações do RM serem muito semelhantes entre EFC e EANCNP, não é possível diagnosticar com total precisão.

Computed tomography and anatomy of the abdominal structures in the giant anteater (Myrmecophaga tridactyla).

The giant anteater (Myrmecophaga tridactyla) is the largest of the Neotropical vermilinguans. This animal is the second mammal most frequently run over on the roads of Cerrado biome, Brazil. Therefore, it is pivotal to know the anatomy of this species to contribute to the clinical care of these animals. Thus, the aim of this study was to identify the anatomical structures in the abdominal region of the giant anteater using computed tomography (CT). For this, the tomographic analysis was performed in sequential order in the craniocaudal direction in five giant anteaters. Moreover, four giant anteater corpses were used for anatomical studies, where two corpses were sectioned in cross sections of approximately 3 cm each, and two animals were dissected to identify the abdominal organs. The association between CT and anatomical study allowed the visualization of anatomical structures found in the abdominal cavity, such as the topographic anatomy facilitates the identification of organs on CT images. The findings of this study demonstrated that CT is a good technique to provide detailed information about the anatomical structures in the abdominal cavity and that this study can be used as CT and anatomical reference for veterinarians who care for wild animals.

Extended reality veterinary medicine case studies for diagnostic veterinary imaging instruction: Assessing student perceptions and examination performance.

Educational technologies in veterinary medicine aim to train veterinarians faster and improve clinical outcomes. COVID-19 pandemic, shifted face-to-face teaching to online, thus, the need to provide effective education remotely was exacerbated. Among recent technology advances for veterinary medical education, extended reality (XR) is a promising teaching tool. This study aimed to develop a case resolution approach for radiographic anatomy studies using XR technology and assess students' achievement of differential diagnostic skills. Learning objectives based on Bloom's taxonomy keywords were used to develop four clinical cases (3 dogs/1 cat) of spinal injuries utilizing CT scans and XR models and presented to 22 third-year veterinary medicine students. Quantitative assessment (ASMT) of 7 questions probing 'memorization', 'understanding and application', 'analysis' and 'evaluation' was given before and after contact with XR technology as well as qualitative feedback via a survey. Mean ASMT scores increased during case resolution (pre 51.6% (±37%)/post 60.1% (± 34%); p < 0.01), but without significant difference between cases (Kruskal-Wallis H = 2.18, NS). Learning objectives were examined for six questions (Q1-Q6) across cases (C1-4): Memorization improved sequentially (Q1, 2 8/8), while Understanding and Application (Q3,4) showed the greatest improvement (26.7%-76.9%). Evaluation and Analysis (Q5,6) was somewhat mixed, improving (5/8), no change (3/8) and declining (1/8).Positive student perceptions suggest that case studies' online delivery was well received stimulating learning in diagnostic imaging and anatomy while developing visual-spatial skills that aid understanding cross-sectional images. Therefore, XR technology could be a useful approach to complement radiological instruction in veterinary medicine.

Morphometric descriptive report of scleral ossicle rings, by ultrasound and computed tomography, in three Testudines specimens / Relato descritivo morfobiométrico dos anéis de ossículos esclerais, por ultrassonografia e tomografia computadorizada, em três espécimes de Testudines

The scleral ossicle rings function has been related to mechanical protection, muscle fixation, support for eyeball shape and visual accommodation. There are few morphobiometric reports on these rings in different Testudines species, and we performed ultrasound (US) and computed tomography (CT) of the scleral ossicle rings in one green turtle (Chelonia mydas), one black-bellied slider (Trachemys dorbigni) and one red-footed tortoise (Chelonoidis carbonarius). The US and CT of the ossicle rings were performed for anatomical identification. The thickness, density, width, and diameters of each ring were measured. The US and CT of the scleral ossicle rings of three animals showed single and continuous circular structures, located in the anterior pole. These structures were easily observed in C. mydas, whose rings were the biggest, thickest and widest. The T. dorbigni CT presented decreased dimensions and the ossicles were the most difficult to identify. Bone density in the superior region was greater than in the inferior of each ring in all animals. Non-invasive imaging exams are good tools to study the anatomy of the ocular skeleton. The scleral ossicle rings of the three specimens presented general morphological similarities and CT enabled visualizing a greater number of details of the ring bone morphology.

Os anéis de ossículos esclerais têm sua função relacionada à proteção mecânica, fixação muscular, suporte para o formato do bulbo ocular e acomodação visual, contudo existem poucos relatos morfobiométricos sobre esses anéis em diferentes espécies de Testudines. Desta forma, foi realizada a avaliação morfobiométrica, por ultrassom (US) e tomografia computadorizada (TC), dos anéis de ossículos esclerais em uma tartaruga verde (Chelonia mydas), um tigre-d'água (Trachemys dorbigni) e um jabuti-piranga (Chelonoidis carbonarius). Foram realizadas US e TC dos anéis esclerais dos três animais para identificação anatômica, espessura, densidade, largura e diâmetros. A US e a TC dos três animais mostraram estruturas circulares únicas e contínuas, localizadas no polo anterior. Estas estruturas foram facilmente observadas na C. mydas, cujos anéis eram os maiores, mais espessos e mais largos. A TC da T. dorbigni apresentou dimensões reduzidas e os ossículos foram dificilmente identificados. A densidade óssea na região superior foi maior comparativamente a parte inferior de cada anel, em todos os animais. Exames de imagem não invasivos mostraram-se bons instrumentos para estudo do esqueleto escleral. Os anéis de ossículos esclerais dos três espécimes apresentaram semelhanças morfológicas gerais e a TC permitiu visualizar um maior número de detalhes da morfologia óssea do anel.

Novel computed tomographic analysis demonstrates differences in patterns of bone mineral content between fracture configurations in distal condylar fractures of the third metacarpal/metatarsal bones in 97 Thoroughbred racehorses.

OBJECTIVE: To evaluate bone mineral content patterns between fracture configurations using novel CT image analysis. ANIMALS: CT images from 97 Thoroughbred racehorses with third metacarpal/tarsal condyle fractures provide the case population for analysis. PROCEDURES: Fractures were grouped by radiographic appearance. Image analysis objectively measured area of highly attenuating pixels (aHAP), areal density of highly attenuating pixels (dHAP) utilizing novel convex hull analysis, and subjective assessment of apparent attenuation intensity ranking (AAIR) for each fracture. Differences between fracture configuration groups were evaluated. RESULTS: Analysis of dHAP identified lower-density regions of highly attenuating pixels in propagating fractures and higher-density regions of highly attenuating pixels in unicortical fractures (P = .028). Complete and incomplete configurations were almost indistinguishable in dHAP (P = 1.000). The ratio of dHAP between fractured and nonfractured condyles revealed higher density gradients between condyles in unicortical (P = .040) and incomplete (P = .031) fractures than propagating fractures. CLINICAL RELEVANCE: Differences in patterns of bone mineral content were identified between propagating, bicortical (incomplete and complete), and unicortical fractures of third metacarpal/tarsal bone condyles. Computer-assisted geometric measurement of dHAP identified on CT images could help to assess fracture risk in equine athletes. This application may have greater relevance as standing CT screening becomes more available.

Anatomy of the nasolacrimal duct in Persian cats determined by computed tomographic dacryocystography.

OBJECTIVE: This study sought to describe the anatomical characteristics of the nasolacrimal duct of Persian cats as observed by computed tomographic dacryocystography. ANIMAL STUDIED: Ten cats weighing 3-6 kg (three live cats and seven cadaveric specimens). PROCEDURES: The animals were submitted to bilateral computed tomographic dacryocystography, totaling 20 nasolacrimal ducts. Dorsal, sagittal, and transverse planes were studied. Two additional skulls were also dissected following latex injection into the nasolacrimal duct. The length and width of the nasolacrimal duct and lacrimal canaliculi, and the distance between the nasolacrimal duct and the root of the upper canine tooth at the point of closest proximity were measured. RESULTS: The nasolacrimal duct followed a convoluted course, particularly in the middle and rostral portions. Duct stenosis (width reduction equal to or >75%) and dilations (width increase equal to or >50%) were also detected, particularly in the rostral portion. Nasolacrimal duct length and width ranged from 1.3 to 1.5 cm and 1.5 to 2.3 mm, respectively. Mean lacrimal canaliculus length and width corresponded to 3.1 mm and 0.4 mm, respectively. Mean distance from the nasolacrimal duct to the canine tooth was 2.4 mm. The root of this tooth interfered with the course of the nasolacrimal duct. CONCLUSION: This study provided anatomical information for clinical assessment of the nasolacrimal drainage system in Persian cats.

Tumor Venéreo Transmissível (TVT) nasal com metástase óssea em um cão / Nasal transmissible venereal tumor (TVT) with bone metastasis in a dog

Background: Transmissible venereal tumor (TVT) is a highly contagious round cell neoplasm that affects dogs, and itis usually transmitted through coitus. The tumor is mainly located in the genital area; however, the neoplasm can also beextragenital, affecting the nose, mouth, and eyes, as well as the skin and superficial lymph nodes. Cytological examinationis the most commonly used method for definitive diagnosis due to its low cost and fast execution. Chemotherapy, radiotherapy, surgical resection, and other procedures such as cryosurgery are the possible treatment options. The objective ofthis report was to describe a case of extragenital TVT with nasal primary site and metastasis in the bone tissue in a dogtreated at a private veterinary hospital in the city of Belém, Pará, Brazil.Case: A 6-year-old male domiciliary Labrador Retriever dog, weighing 24.2 kg, received oncologic treatment in a privateveterinary hospital in the city of Belém, Pará, Brazil. The animal had a history of neoplastic disease, and he had undergoneTVT resection associated with chemotherapy treatment more than 3 years ago. The clinical examination revealed a volumeincrease in the periorbital region, left lateral ocular displacement, left nostril excessive epistaxis, recurrent sneezing, cough,and pain signs, and tumor metastasis was suspected. Complementary exams of oncological cytology, computed tomography(CT), hemogram, and serum biochemistry were requested for diagnosis and staging of the condition, and supportive therapywas prescribed. The cytological report showed a dense population of neoplastic round cells with characteristics of TVT. CTindicated the presence of a heterogeneous hypodense mass with irregular contours and partially defined limits, with slightuptake of the intravenously injected contrast medium that obliterated the nasal cavity, maxillary recess, nasopharyngealmeatus, frontal sinus, and sphenoid sinus on the left side...(AU)

Tumor Venéreo Transmissível (TVT) nasal com metástase óssea em um cão / Nasal transmissible venereal tumor (TVT) with bone metastasis in a dog

Background: Transmissible venereal tumor (TVT) is a highly contagious round cell neoplasm that affects dogs, and itis usually transmitted through coitus. The tumor is mainly located in the genital area; however, the neoplasm can also beextragenital, affecting the nose, mouth, and eyes, as well as the skin and superficial lymph nodes. Cytological examinationis the most commonly used method for definitive diagnosis due to its low cost and fast execution. Chemotherapy, radiotherapy, surgical resection, and other procedures such as cryosurgery are the possible treatment options. The objective ofthis report was to describe a case of extragenital TVT with nasal primary site and metastasis in the bone tissue in a dogtreated at a private veterinary hospital in the city of Belém, Pará, Brazil.Case: A 6-year-old male domiciliary Labrador Retriever dog, weighing 24.2 kg, received oncologic treatment in a privateveterinary hospital in the city of Belém, Pará, Brazil. The animal had a history of neoplastic disease, and he had undergoneTVT resection associated with chemotherapy treatment more than 3 years ago. The clinical examination revealed a volumeincrease in the periorbital region, left lateral ocular displacement, left nostril excessive epistaxis, recurrent sneezing, cough,and pain signs, and tumor metastasis was suspected. Complementary exams of oncological cytology, computed tomography(CT), hemogram, and serum biochemistry were requested for diagnosis and staging of the condition, and supportive therapywas prescribed. The cytological report showed a dense population of neoplastic round cells with characteristics of TVT. CTindicated the presence of a heterogeneous hypodense mass with irregular contours and partially defined limits, with slightuptake of the intravenously injected contrast medium that obliterated the nasal cavity, maxillary recess, nasopharyngealmeatus, frontal sinus, and sphenoid sinus on the left side...

Retrospective study on the incidence of cats and dogs' spinal injuries by computed tomographic scan. Part I: Cervical and Cervicothoracic / Estudo retrospectivo sobre incidência de injúrias em coluna vertebral de cães e gatos por meio de exame tomográfico. Parte I: Cervical e Cervicotorácica

Injuries involving the spine are frequent in dogs and knowledge of them is important to define the patient's treatment and prognosis. The objective of this retrospective study was to describe the epidemiological profile of animals and lesions in the cervical (C1-5) and cervicothoracic (C6-T2) spine diagnosed through tomographic examination. Compilation of computed tomography (CT) reports for the referred regions was carried out in a diagnostic center between 01/04/2017 and 30/04/2020, with or without contrast, from the clinical routine, in order to relate the most common lesions and their locations, as well as the species, breeds and ages most affected. A total of 1164 CT scans were performed in the period, 57.56% (n=670/1164) for the spine, with 89.7% (n=601/670) reports accessed, where both regions referred to here totaled 26.95% of the studies (n=162/601). Male mixed-breed dogs (MBD) showed the most lesions. For the cervical spine, the most identified lesion was disk extrusion and the site was C3-C4, while the mean age for lesions was 8.09±3.55 years. As for cervicothoracic, disk mineralization was more frequent and the mean age for lesions was 6.96±2.93 years. It was concluded that the spine is the main target of CT scans, that lesions related to the intervertebral disk were the main ones identified, and older MBD animals are the main ones affected.

As lesões envolvendo coluna vertebral são frequentes em animais de companhia, podendo ocorrer à nível vertebral, medula espinal, disco intervertebral, meninges ou raízes nervosas, e o conhecimento das mesmas é importante para definir o tratamento e prognóstico do animal. O objetivo desse estudo retrospectivo foi descrever o perfil epidemiológico dos animais e das lesões em coluna vertebral cervical (C1-5) e cervicotorácica (C6-T2) diagnosticadas por meio de exame tomográfico. Realizou-se a compilação de laudos de tomografias computadorizadas para as referidas regiões realizadas em centro diagnóstico comercial, entre 01/04/2017 a 30/04/2020, contrastadas e não-contrastadas, provenientes da rotina clínica, a fim de relacionar as lesões, raças e locais mais comuns. Foram realizados 1164 exames tomográficos no período avaliado, sendo 57,56% (n=670/1164) para a coluna, com 89,7% dos laudos acessados (n=601/670), sendo que as regiões cervical e cervicotorácica somaram 26,95% dos estudos (n=162/601). Em ambas regiões, os cães sem raça definida (SRD) machos foram os que mais demonstraram lesões. Para a coluna cervical, a lesão mais identificada foi extrusão de disco e o local mais afetado foi C3-C4, enquanto a média de idade para lesões foi 8,09±3,55 anos. Já para cervicotorácica, a mineralização de disco foi mais frequente e média de idade para ocorrência de lesões foi de 6,96±2,93 anos. Concluiu-se que a coluna vertebral foi o principal alvo de tomografias, as lesões relacionadas ao disco intervertebral foram as mais identificadas, sendo animais SRD com idade avançada os mais acometidos.

Retrospective study on the incidence of cats and dogs' spinal injuries by computed tomographic scan. Part II: Thoracolumbar and lumbosacral / Estudo retrospectivo sobre incidência de injúrias em coluna vertebral de cães e gatos por meio de exame tomográfico. Parte II: Toracolombar e Lombossacral

For vertebromedullary injuries, epidemiological knowledge is essential to guide the choice of the most effective diagnostic method. The objective of this retrospective study was to describe the epidemiological profile of animals and thoracolumbar and lumbosacral spine lesions diagnosed by computed tomography scan. A compilation of CT scan reports for the aforementioned regions performed in a comercial diagnostic center from 04/01/2017 to 04/30/2020, contrasted and non-contrasted, from routine, was performed in order to list the most common lesions and their locations, as well as the species, breeds and ages most affected. There were 1164 CT scans performed in the period evaluated, all of them in dogs, 57,56% (n=670) for the spine, with 89,7% reports accessed (n=601), where the regions mentioned here added up to 73,05% studies (n=439). In both regions, male French Bulldog dogs had the most injuries. For the thoracolumbar region, disk mineralization, followed by extrusion, were the most frequent injuries, while the site was T12-13 and the mean age 6,5±3,63 years old. In the lumbosacral, disk protrusion was most frequent, the most affected site was L7-S1 and age 6,65±3,79 years. It was concluded that the spine is the main target of CT scans, and that lesions related to the intervertebral disk were the main ones identified, with chondrodystrophic animals being more predisposed to injury.

Para lesões vertebromedulares é indispensável o conhecimento epidemiológico para direcionar a escolha do método diagnóstico mais eficaz. O objetivo desse estudo retrospectivo foi descrever o perfil epidemiológico dos animais e das lesões em coluna vertebral toracolombar e lombossacral diagnosticadas através de exame tomográfico. Realizou-se a compilação de laudos de tomografias computadorizadas para as referidas regiões realizadas em centro diagnóstico comercial, entre 01/04/2017 a 30/04/2020, contrastadas e não-contrastadas, provenientes da rotina, a fim de relacionar as lesões e seus locais de ocorrência, bem como a espécie, raças e idades mais comuns. Foram realizados 1164 exames tomográficos no período avaliado, sendo 57,56% (n=670) para a coluna, com 89,7% laudos acessados (n=601), nos quais as regiões toracolombar e lombossacral somaram 73,05% dos estudos (n=439). Em ambas as regiões, os cães Bulldog Francês machos foram os que mais apresentaram lesões. Para a região toracolombar, a mineralização de disco, seguida pela extrusão, foram as lesões mais frequentes, enquanto o local foi T12-13 e a média de idade 6,5±3,63 anos. Na lombossacral, a protusão de disco foi mais frequente, o local mais afetado foi L7-S1 e idade de 6,65±3,79 anos. Concluiu-se que a coluna vertebral é o principal alvo de tomografias, e que as lesões relacionadas ao disco intervertebral foram as principais identificadas, sendo os animais condrodistróficos mais predispostos a lesões.

Qualitative and quantitative evaluation of the ventricular system and brain parenchyma in healthy dogs of different skull conformation on computed tomography scans.

This study aimed to perform quantitative and qualitative evaluations of the lateral and third ventricles, and brain parenchyma, in healthy dogs of different skull conformations on CT scans. Forty-five adult client-owned dogs were divided into three groups according to skull conformation: G1 (dolichocephalic)-15 German Shepherds; G2 (mesaticephalic)-15 Rottweilers; G3 (brachycephalic)-15 Boxers. Transverse plane images were used for quantitative and qualitative evaluations of the lateral ventricles and third ventricle, and pre- and post-contrast brain parenchyma. The height of both ventricles and brain was measured at the level of the interthalamic adhesion. Ventricle height, brain height, and ventricle/brain height ratio were statistically higher in G3 compared with G1 and G2 that were similar. The third ventricle was visible but unmeasurable in five dogs from G1 and three from G2. In G3, all dogs had third ventricle visible and measurable in all images. Asymmetric ventricles were seen in five dogs in Group 1 and Group 2, and seven in Group 3. Brain parenchyma had homogenous density in 80% of the dogs in all groups. Contrast enhancement of the rostral midline was visualized in all dogs. In conclusion, brain CT scans of healthy dogs showed that the qualitative data were similar among groups, but lateral ventricle and brain measurements in brachycephalic dogs differed from the dolichocephalic and mesaticephalic dogs.

Pneumocephalus and suppurative meningoencephalitis in a dog after craniofacial trauma

Background: Pneumocephalus is characterized by the presence of gas in the intracranial compartment, and it can be developed by trauma, craniofacial surgery or spontaneously. Clinical signs start within days or months after the injury and vary according to the site of involvement. Computed tomography is the ideal diagnostic tool, however skull radiography can also be used. Treatment varies according to the severity of the case, and it can be conservative or associated with surgical intervention in the most severe cases. The purpose of this report is to describe the case of a dog that developed pneumocephalus and suppurative meningoencephalitis after head trauma caused by a bite from another dog. Case: A 2-month-old bitch, mixed breed, with 3.2 kg, was referred to the Veterinary Hospital because it had been bitten on the head by another dog. Shortly after the incident, the animal showed no clinical signs. However, 2 days later, the bitch became depressed and in persistent lateral decubitus. A lesion with a crust of approximately 0.5 cm was found close to the occipital region, with bone irregularity on palpation. The animal was in lateral decubitus with muscular hypotonia, bilateral mydriasis unresponsive to light and stupor. Radiographic images showed parietal fracture and pneumocephalus. Based on the findings of physical and laboratorial exams, diagnosis of suppurative meningoencephalitis and pneumocephalus secondary to craniofacial trauma was established. Empirical broad-spectrum antimicrobial therapy was started in addition to mannitol, corticoids, and analgesics. The animal was referred for surgical debridement by trepanation, when samples were collected to bacterial culture, which was negative. Despites the care, the animal died 14 h after the surgical procedure. Histopathological examination of the frontal cortex was performed, being the histological changes compatible with suppurative meningoencephalitis. Discussion: Dog bites on the head and neck are particularly severe, and can create intracranial bleeding, disfigurement of the face, damage to peripheral structures or cranial fractures. In this report, through radiographic images, it was found that the patient had an intracerebral aerocele, since there was presence of gas in the intracranial compartment. This alteration should always be considered in animals with neurological alterations and a history of craniofacial trauma. The main neurological changes observed in the reported case were unresponsive to mydriasis and altered mental status 2 days after the trauma, and this delay in the onset of clinical signs is frequently reported in cases of pneumocephalus. Neutrophilia and leukocytosis observed can be justified by the suppurative meningoencephalitis, confirmed by the histopathological exam. Antimicrobial therapy should be started as soon as possible, and the choice must be based on their capacity to cross the blood-brain barrier and the broad spectrum. The administration of antibiotics before collecting the material for bacterial culture may explain the negative result of this test, so that it is not possible to determine whether the intracranial gas observed on the radiograph may have developed from the trauma or because of gas-producing bacteria. Head trauma can induce suppurative meningoencephalitis and pneumocephalus even in the absence of perforating wounds at the time of the consultation. The neurological signs can start days after the trauma. Besides the clinical and surgical treatments, the prognosis of any bacterial infection of the central nervous system is poor.