Traumatic pericardial rupture with secondary cardiac herniation in a dog.

OBJECTIVE: To describe the unique finding and treatment of a dog with cardiac herniation due to traumatic pericardial rupture. CASE SUMMARY: A 6.5-year-old entire male Yorkshire Terrier was presented for further management after being hit by a car. Despite suspected significant intrathoracic trauma at that time, the patient regained hemodynamic stability and had orthopedic surgery to correct a right iliac fracture. The patient was readmitted to the hospital 12 days following the initial visit due to considerable respiratory difficulty after accidentally being dropped several feet. Thoracic radiographs revealed an unusual severe mediastinal shift to the left with an atypical position of the cardiac silhouette against the left lateral thoracic wall. Due to the severe respiratory compromise of the patient and newly developed pneumothorax, an exploratory thoracotomy was recommended, where a complete rupture of the pericardium was identified, with secondary left-sided prolapse of the heart. Other more common intrathoracic injuries (ie, lung perforation, rib fractures) were also identified and partially repaired. The patient recovered successfully and was discharged 4 days postoperatively. NEW OR UNIQUE INFORMATION PROVIDED: This is the first case report in the veterinary literature of traumatic pericardial rupture and cardiac herniation. According to human case descriptions, this is a rare and often fatal occurrence, which can be significantly challenging to diagnose preoperatively or antemortem. Emergency veterinary clinicians should be aware of this rare but important complication of blunt thoracic trauma. Surgical intervention may be necessary in cases with suspected or confirmed entrapment of great vessels or cardiac chambers, although these abnormalities were not present in this case.

Hyperechogenicity of the pyloroduodenal junction in small dogs: Population prevalence in 175 dogs and histological correlation in 14 specimens.

At the pyloroduodenal junction (PDJ), an increase in wall echogenicity is frequently observed. A prospective study was performed to assess the PDJ sonographically in 175 adults and small dogs (>1 year old, <11.4 kg (25 lb)) over 12 months to evaluate the prevalence of this finding. Additionally, changes in echogenicity were correlated with histology in 14 postmortem specimens. A scoring system of echogenicity change centered on the mucosa and submucosa of the PDJ was implemented; 0: no change, 1: mild, 2: moderate to marked. Other included parameters were age, sex, breed, gastric distention, gastric contents, and reported vomiting at the time of presentation. Hyperechogenicity of the PDJ was highly prevalent (scores 1 and 2: 85.7%). No statistical association between hyperechogenicity of the PDJ and age, sex, gastric distention, gastric contents, or vomiting was identified. Hyperechogenicity of the PDJ is thought to represent an anatomical transition zone, and based on histology, hyperechogenicity of the PDJ may represent a variation in distribution and amount of fibrous connective tissue, glandular number, and glandular dilation within the submucosa and mucosa.

Hippocampal size did not differ between epileptic and non-epileptic dogs using volumetric and subjective methods.

Hippocampal changes in epilepsy may manifest as hippocampal atrophy/sclerosis. A recent human study suggests that the demonstration of hippocampal volume loss is more reliable using quantitative evaluation methods. The aim of the present study was to obtain volumetric data in both epileptic and healthy dogs, to compare hippocampal volumes in both groups, and to compare subjective and volumetric assessment. Volumetric measurements of the hippocampi, lateral ventricles and hemispheria were performed in 31 epileptic and 15 control dogs. There was a positive association between the body weight and the hemispheric volume, as well as between the hemispheric volume and the ipsilateral hippocampal volume. There was no significant correlation between age and the volume of any measured brain structures. There was no statistically significant difference between the hippocampal volumes of the control group and the epileptic group. A statistically significant difference between the two groups for hippocampus/hemispherium ratio or hippocampal asymmetric ratio was not identified. An extrapolated hippocampal volume based on body weight was not possible in this study population.

Canine calvarial subperiosteal hematomas are fluid to soft tissue attenuating mass-like lesions with smoothly marginated peripheral mineralization on CT.

Subperiosteal hematomas are accumulations of blood between a bone and the periosteum leading to elevation of the periosteum. When ossified they have a mineralized outer rim. For this retrospective, multi-institutional case series, medical records were searched to identify dogs that underwent CT for focal calvarial swellings noted acutely after trauma. A total of four dogs were included. Computed tomography images were reviewed for each case. The focal swellings had progressed in size during the weeks after the head trauma until the time of imaging. Findings in all cases included a fluid to soft tissue attenuating mass-like lesion with smoothly marginated peripheral mineralization. Diagnosis was confirmed in two cases by cytology and/or histopathology. Therefore, authors recommend that subperiosteal hematoma be included in the differential diagnosis list for dogs with these clinical and CT characteristics. Based on our review of the literature, this is the first report to describe the CT features of calvarial subperiosteal hematomas in dogs.

Ultrasonographic measurement of adrenal gland-to-aorta ratio as a method of estimating adrenal size in dogs.

BACKGROUND: Adrenal size has been used as the principal criterion for differentiating a normal gland from adrenal hyperplasia. The objectives of this study were to establish an ultrasonographic measurement of adrenal gland-to-aorta (adrenal/Ao) ratio to estimate the adrenal size and to assess the effects of bodyweight, age and sex on the adrenal/Ao ratio in non-adrenal gland disease dogs. METHODS: Two hundred and thirty-four dogs (120 entire females and 114 entire males) considered non-adrenal gland disease were included in this study. Dogs were allocated into three bodyweight categories (<10 kg, 10-20 kg and >20 kg), and four age groups (<1 year, 1-5 years, 5-10 years and >10 years old). Measurements of the maximal thickness of caudal pole of both adrenal glands and the aortic luminal diameter in sagittal plane were performed on the ultrasonographic images. Three different ratios were calculated for each dog. RESULTS: Sex and age did not influence on the adrenal/Ao ratio. There were differences (P<0.05) between the three dog sizes for adrenal/Ao ratio, being the highest value for small size and the lowest value for large size. CONCLUSIONS: In this study, only bodyweight influences the ultrasound measurement of the adrenal/Ao ratio in non-adrenal gland disease dogs.

A Review of Immunotherapeutic Strategies in Canine Malignant Melanoma.

In dogs, melanomas are relatively common tumors and the most common form of oral malignancy. Biological behavior is highly variable, usually aggressive, and frequently metastatic, with reported survival times of three months for oral or mucosal melanomas in advanced disease stages. Classical clinical management remains challenging; thus, novel and more efficacious treatment strategies are needed. Evidence-based medicine supports the role of the immune system to treat neoplastic diseases. Besides, immunotherapy offers the possibility of a precise medicinal approach to treat cancer. In recent years, multiple immunotherapeutic strategies have been developed, and are now recognized as a pillar of treatment. In addition, dogs represent a good model for translational medicine purposes. This review will cover the most relevant immunotherapeutic strategies for the treatment of canine malignant melanoma, divided among five different categories, namely, monoclonal antibodies, nonspecific immunotherapy activated by bacteria, vaccines, gene therapy, and lymphokine-activated killer cell therapy.

Computed tomographic retrograde positive contrast cystography and computed tomographic excretory urography characterization of a urinary bladder diverticulum in a dog.

A one-year-old intact male German shepherd dog was referred with a 3-month history of dysuria and pollakiuria. Physical examination revealed a large firm mass in the caudal abdomen. Findings from survey radiography, negative contrast cystography, computed tomographic (CT) retrograde positive contrast cystography, and CT excretory urography were consistent with a large urinary bladder diverticulum. An exploratory laparotomy revealed a normal wall appearance in the ventral compartment (true bladder) and marked thinning of the wall in the dorsal compartment (diverticulum). Both ureters inserted into the ventral compartment. The dorsal compartment was excised and histopathology confirmed the diagnosis of urinary bladder diverticulum.

Selected serum oxidative stress biomarkers in dogs with non-food-induced and food-induced atopic dermatitis.

BACKGROUND: Oxidative stress (OS) has been shown to be involved in the pathogenesis of human and canine atopic dermatitis (AD) through several distinct mechanisms. Selected serum biomarkers of OS (sbOS) have been validated in normal dogs and studied in several canine diseases. To the best of the authors' knowledge, the sbOS evaluated in this study have not previously been described in canine AD. HYPOTHESIS/OBJECTIVES: The aims of the study were to evaluate a panel of sbOS in dogs with food-induced (FIAD) and non-food-induced (NFIAD) AD: cupric reducing antioxidant capacity (CUPRAC), ferrous oxidation-xylenol orange (FOX), ferric reducing ability of the plasma (FRAP), paraoxonase-1 (PON1), trolox equivalent antioxidant capacity (TEAC) and serum total thiol (THIOL). The aim was to compare these metabolites with those in healthy control dogs, and to correlate sbOS with validated pruritus and CADESI-04 severity scales in dogs with AD. ANIMALS: Forty six healthy, nine NFIAD and three FIAD client-owned dogs were included. METHODS: The study was designed as a cohort study. RESULTS: There were significant differences in atopic dogs when compared to healthy dogs for all of the sbOS analysed. CONCLUSIONS AND CLINICAL RELEVANCE: These findings suggest that OS could play a role in the pathogenesis of canine NFIAD and FIAD. In addition, the evaluation of sbOS could be useful for precision medicine to help to detect atopic dogs that might benefit from antioxidant-targeted therapies.

IMAGING DIAGNOSIS-COMPUTED TOMOGRAPHY FINDINGS IN A DOG WITH SPONTANEOUS TRANSMURAL MIGRATION OF A TEXTILOMA INTO THE CECUM.

A 3-year-old spayed female dog was presented with 3-month history of severe bilateral uveitis subsequent to previous ovariohysterectomy. Physical examination revealed moderate abdominal pain. Computed tomography showed a nonobstructive heterogeneous mass-like lesion with a speckled gas pattern (spongiform pattern) within the cecum. Exploratory laparotomy revealed a surgical swab in the lumen of the cecum with severe adhesions. Histopathological examination demonstrated a chronic inflammatory pyogranulomatous reaction to the retained swab embedded within the intestinal wall, consistent with transmural migration of the swab from the peritoneal cavity into the cecum.

IMAGING DIAGNOSIS-RADIOGRAPHY AND COMPUTED TOMOGRAPHY OF RADIOULNAR ISCHEMIC NECROSIS IN A JACK RUSSELL TERRIER.

A 7-year-old Jack Russell Terrier with a history of minor trauma was presented for lameness of the left forelimb. Radiography and computed tomography demonstrated a localized radioulnar osteolytic lesion with cortical bone loss and enthesiophytes. Based on results of diagnostic imaging and histopathological examination, the final diagnosis was radioulnar ischemic necrosis (RUIN), complicated by pathologic fracture. A rare disorder of unknown etiology, RUIN may be secondary to tearing of the interosseous ligament and potential ischemia. It should be differentiated from neoplastic or fungal disease. To the authors´ knowledge, this is the first canine case report describing RUIN.

Novel approach to magnetic resonance imaging of epileptic dogs - T2 relaxometry of the brain with emphasised hippocampus.

Hippocampal sclerosis is the most common imaging finding of intractable human epilepsy, and it may play an important role in canine and feline epileptogenesis and seizure semiology, too. The magnetic resonance imaging (MRI) criteria of hippocampal sclerosis are T2 hyperintensity, shrinkage and loss of internal structure. The detection of these changes is often challenging by subjective visual assessment of qualitative magnetic resonance (MR) images. The recognition is more reliable with quantitative MR methods, such as T2 relaxometry. In the present prospective study including 31 dogs with idiopathic epilepsy and 15 control dogs showing no seizure activity, we compared the T2 relaxation times of different brain areas. Furthermore, we studied correlations between the hippocampal T2 values and age, gender and skull formation. We found higher hippocampal T2 values in the epileptic group than in the control; however, these findings were not statistically significant. No correlations were found with age, gender or skull formation. In the individual analysis six epileptic dogs presented higher hippocampal T2 relaxation times than the cut-off value. Two of these dogs were also evaluated as abnormal in the visual assessment. Individual analysis of hippocampal T2 relaxation times may be a helpful method to understand hippocampal involvement in canine epilepsy.

Subcutaneous extraskeletal osteosarcoma in a metatarsal footpad in a cat.

BACKGROUND: Extraskeletal osteosarcomas (ESOSAs) are rare neoplasms in humans and animals. In cats, ESOSA has been reported to arise from orbital, ocular, intestinal, mammary and subcutaneous locations. Subcutaneous ESOSA occurs most commonly at sites used for vaccination including interscapular, dorsal lumbar or thigh areas. Previous reports of feline cases have not documented the use of advanced diagnostic imaging to exclude a primary bone tumour. OBJECTIVE: To describe the clinicopathological and advanced imaging findings of a subcutaneous ESOSA occurring in a metatarsal footpad of a cat and to report the one year follow-up status. ANIMAL: A 9-year-old neutered male domestic short hair cat. METHODS: Physical, abdominal ultrasonographic and computed tomographic examinations, and excisional biopsy for histopathological and immunohistochemical evaluation. RESULTS: The cat presented with mild focal erythematous swelling of the left metatarsal pad. ESOSA was diagnosed through advanced diagnostic imaging and histopathological examinations. Histopathological findings were consistent with osteosarcoma. No primary bone disease was observed on computed tomography. The owners declined limb amputation. One year after diagnosis, the cat was alive without disease progression. CONCLUSIONS AND CLINICAL IMPORTANCE: Extraskeletal osteosarcoma should be considered in the differential diagnosis of soft tissue swelling in footpads in cats. Advanced diagnostic imaging is recommended to exclude primary bone tumours.

Evaluation of an ultrasound-guided technique for axillary brachial plexus blockade in cats.

Objectives The aim of this study was to evaluate and refine an ultrasound (US)-guided technique to block the brachial plexus (BP) at the level of the axillary space in live cats. Methods Eight adult experimental cats were enrolled into the study. The animals were sedated and positioned in dorsal recumbency with the limb to be blocked abducted 90º. The US transducer was placed in the axillary region and a non-traumatic peripheral nerve block needle was inserted in-plane with respect to the transducer, medial to the BP up to the level of the axillary artery. Lidocaine 1% (0.4 ml/kg) was injected as the needle was being progressively withdrawn in a caudal-to-cranial direction. The efficacy of the block was confirmed by evaluation of the motor and sensory functions of the blocked forelimb. Motor blockade was assessed observing the position of the blocked leg on standing and walking patterns. Sensory blockade was evaluated by the stimulation of mechanical nociceptors in the dermatomes supplied by the four major sensory nerves of the distal thoracic limb. Results The BP was successfully located by US in all cases. The achieved BP block was complete in six cats (75%) and partial in the remaining two cats (25%). All animals recovered uneventfully from the sedation and the BP blocks. Conclusions and relevance The US-guided block at the axillary space evaluated in this study is a feasible, reproducible and safe technique to block the BP plexus in experimental live cats.

IMAGING DIAGNOSIS-URETHROVAGINAL FISTULA CAUSED BY A MIGRATING GRASS AWN IN THE VAGINA.

A young intact female dog was presented with urinary incontinence. Abdominal ultrasound revealed the presence of hyperechoic linear structures within the cranial vagina suggestive of foreign material. A computed tomography (CT) retrograde vaginourethrogram demonstrated the presence of a fistulous tract between the urethra and vagina. A presumptive diagnosis of urethrovaginal fistula due to migration of foreign material was made. The grass awn was removed with vaginoscopic-guided retrieval. Fourteen days later, surgical repair of the fistula and an ovariohysterectomy were done. This case report emphasizes the usefulness of CT for diagnosis and precise anatomical localization of genitourinary tract fistulas.

Comparison of two techniques for ultrasound-guided axillary brachial plexus blockade in cats.

Axillary blockade of the brachial plexus (BP) is advocated in humans and dogs for surgical procedures carried out on the foot, carpus and elbow as it provides complete analgesia distally from above the elbow joint. The aim of this study was to develop an ultrasound (US)-guided approach to block the BP in cats. Two groups of 12 feline cadavers each were used to compare two different techniques to block the BP at the axillary level. The reliability of the techniques was assessed by anatomical and computed tomography (CT) studies. Cadavers of the first group were positioned in dorsal recumbency with the forelimb to be blocked adducted (thoracic limbs flexed and orientated caudally) (FAD technique). The second group was positioned in dorsal recumbency with the forelimb abducted 90° (FAB technique). The accuracy of the techniques was determined by US after injecting 1 ml blue ink along the BP nerves, and by CT after injecting 1 ml of an iodinated contrast medium. The anatomical and CT studies confirmed the accuracy of the US location of the BP nerves. Staining of the axillaris, musculocutaneous, radialis, medianus and ulnaris nerves was observed in 100% of cats using the FAB technique and in 66% of the cats using the FAD technique. Rate of complications was higher in the FAD technique. In conclusion, a US-guided axillary approach to the BP by the use of a FAB technique is a safe and feasible procedure to block the BP in the cat. Further studies are needed to ascertain whether the technique can be applied in a clinical setting.

IMAGING DIAGNOSIS-SPONTANEOUS PNEUMOMEDIASTINUM SECONDARY TO PRIMARY PULMONARY PATHOLOGY IN A DALMATIAN DOG.

A 1.5-year-old, 23 kg intact male Dalmatian dog was evaluated for acute respiratory insufficiency without a previous history of trauma or toxic exposition. Imaging revealed pneumomediastinum, pneumothorax, diffuse unstructured interstitial pulmonary pattern, pulmonary interstitial emphysema, and pneumoretroperitoneum. Histopathological evaluation of the lungs revealed perivascular and peribronchial emphysema, mild lymphocytic interstitial pneumonia with atypical proliferation of type II pneumocytes in bronchioles and alveoli. A lung disease resembling fibrosing interstitial pneumonia in man and cats has been previously reported in Dalmatians and should be included as a differential diagnosis for Dalmatians with this combination of clinical and imaging characteristics.

Imaging diagnosis-infiltrative lipoma causing spinal cord and lumbar nerve root compression in a dog.

A 12-year-old, male, fox terrier dog presented with an abnormal gait of the left pelvic limb. Computed tomography revealed a large, homogeneous, hypoattenuating, noncontrast enhancing mass within the left epaxial muscles that invaded the L5-6 vertebral canal and caused spinal cord compression. Imaging findings were consistent with an infiltrative lipoma. The mass was removed and a left hemilaminectomy was performed in the affected area. Histopathology confirmed the mass to be an infiltrative lipoma. The dog recovered and regained neurologic function within 2 weeks. Computed tomography assisted preoperative planning by characterizing the shape, size, and location of the mass.

Correlative ultrasound anatomy of the feline brachial plexus and major nerves of the thoracic limb.

Brachial plexus avulsions commonly occur in cats due to traumatic injuries involving the shoulder. Ultrasound may be an effective method for detecting injured nerves. Additional applications may include characterization of brachial plexus neoplasms and guidance of anesthetic nerve blocks. Aims of this study were to describe ultrasonographic approaches and the normal appearance of this plexus and other major nerves of the thoracic limb in cats. Eight feline cadavers were used to determine anatomic landmarks, obtain cross-sectional anatomic images of the target nerves, and compare these with ultrasound images. An ultrasonographic study was performed in five fresh feline cadavers to assess the brachial plexus and its major components at the levels of the axilla and proximal, middle and distal (lateral and medial approaches) humeral regions. Five healthy adult cats were recruited for an in vivo ultrasonographic study using the same protocol described for the cadaver ultrasonographic study. The roots of the brachial plexus appeared as a cluster of small, round hypoechoic structures surrounded by a hyperechoic rim in the axillary approach. The radialis, medianus, and ulnaris nerves were individually visualized on proximal and middle humeral approaches. The medianus and ulnaris nerves were easily identified on the medial aspect of the humerus in the distal approach. The superficial branch of radialis nerve was seen on the lateral aspect of the distal humerus approach. The nerves appeared as oval-to-round hypoechogenic structures with a hyperechogenic rim. Future studies are needed to compare findings from this study with those in cats with confirmed brachial plexus injuries or other lesions.