Ultrasound- and fluoroscopy-guided percutaneous transhepatic shunt attenuation using a vascular plug in a complex canine intrahepatic portosystemic shunt.

A 5-month-old Pembroke Welsh corgi dog was presented with a 3-month history of lethargy, inappetence, polyuria/polydipsia, and neurological signs. A diagnosis of a complex multiple intrahepatic portosystemic shunt (IHPSS) configuration was obtained by computed tomography angiogram, abdominal ultrasonography, and perioperative fluoroscopic angiography. The IHPSS was successfully attenuated by shunt embolization with a vascular plug, using a direct percutaneous hepatic approach under ultrasonographic and fluoroscopic guidance. Long-term (4 y) follow-up revealed resolution of all clinical signs. The owner elected to continue dietary modification and lactulose treatment indefinitely and the outcome was considered good. Key clinical message: Direct percutaneous hepatic approach could be considered for IHPSS attenuation in select cases where traditional transvenous approach access is considered challenging.

Atténuation percutanée trans-hépatique guidée par échographie et fluoroscopie d'un shunt porto-systémique intrahépatique canin complexe à l'aide d'un bouchon vasculaireUn chien Pembroke Welsh corgi âgé de 5 mois a été présenté avec des antécédents de léthargie, d'inappétence, de polyurie/polydipsie et de signes neurologiques depuis 3 mois. Un diagnostic de configuration complexe de shunt porto-systémique intrahépatique multiple (IHPSS) a été obtenu par angiographie par tomodensitométrie, échographie abdominale et angiographie fluoroscopique périopératoire. L'IHPSS a été atténué avec succès par embolisation du shunt avec un bouchon vasculaire, en utilisant une approche hépatique percutanée directe sous guidage échographique et fluoroscopique. Un suivi à long terme (4 ans) a révélé une résolution de tous les signes cliniques. Le propriétaire a choisi de poursuivre indéfiniment la modification du régime alimentaire et le traitement au lactulose et le résultat a été considéré comme bon.Message clinique clé :Une approche hépatique percutanée directe pourrait être envisagée pour l'atténuation de l'IHPSS dans certains cas où l'accès par voie trans-veineuse traditionnelle est considéré comme difficile.(Traduit par Dr Serge Messier).

Abdominal radiographic features of anticoagulant rodenticide toxicity in 14 dogs and 2 cats.

Background: Anticoagulant rodenticide toxicity is commonly encountered in veterinary practice that can result in internal bleeding. We have observed dogs with retroperitoneal hemorrhage secondary to anticoagulant rodenticide toxicity. However, abdominal radiographic changes in dogs with rodenticide toxicity have not been studied and retroperitoneal hemorrhage secondary to rodenticide toxicity has rarely been reported. Aim: The objective is to describe abdominal radiographic features of anticoagulant rodenticide toxicity and concurrent thoracic radiographic changes in dogs and cats. Methods: Dogs and cats diagnosed with rodenticide toxicity and with available abdominal radiographs were included in this retrospective analysis. Board-certified radiologists reviewed the abdominal and thoracic radiographs. Evaluation of abdominal radiographic changes included assessment of peritoneal or retroperitoneal effusion, subcutaneous hemorrhage, and internal hemorrhage of abdominal organs. Results: Fourteen dogs and two cats with confirmed rodenticide toxicity were included in the study. In dogs, retroperitoneal effusion (28.6%) was the most commonly observed abdominal radiographic change, followed by peritoneal effusion (14.3%). Thoracic radiographic changes in dogs included pleural effusion (63.6%) and mediastinal widening (63.6%) as the most common findings, followed by pulmonary hemorrhage (36.4%) and tracheal narrowing (36.4%). Subcutaneous hemorrhage or edema (9.1%) was also noted. No abdominal radiographic changes consistent with hemorrhage secondary to rodenticide toxicity were noted in the two cats. Conclusion: Based on our findings, it is suggested that rodenticide toxicity may result in retroperitoneal effusion even in the absence of thoracic disease. Therefore, abdominal radiographs may be valuable when suspecting hemorrhage due to coagulopathy. However, abdominal radiographic changes associated with rodenticide toxicity are considered rare in cats.

Exploring deep learning strategies for intervertebral disc herniation detection on veterinary MRI.

Intervertebral Disc Herniation (IVDH) is a common spinal disease in dogs, significantly impacting their health, mobility, and overall well-being. This study initiates an effort to automate the detection and localization of IVDH lesions in veterinary MRI scans, utilizing advanced artificial intelligence (AI) methods. A comprehensive canine IVDH dataset, comprising T2-weighted sagittal MRI images from 213 pet dogs of various breeds, ages, and sizes, was compiled and utilized to train and test the IVDH detection models. The experimental results showed that traditional two-stage detection models reliably outperformed one-stage models, including the recent You Only Look Once X (YOLOX) detector. In terms of methodology, this study introduced a novel spinal localization module, successfully integrated into different object detection models to enhance IVDH detection, achieving an average precision (AP) of up to 75.32%. Additionally, transfer learning was explored to adapt the IVDH detection model for a smaller feline dataset. Overall, this study provides insights into advancing AI for veterinary care, identifying challenges and exploring potential strategies for future development in veterinary radiology.

Retrospective evaluation of radiofrequency volumetric tissue reduction for hypertrophic turbinates in dogs with brachycephalic obstructive airway syndrome.

OBJECTIVE: The objective of this study was to retrospectively assess the effect of Radiofrequency Volumetric Tissue Reduction (RFVTR) on hypertrophic turbinates and clinical outcome in brachycephalic dogs when included in multi-level surgery (MLS). STUDY DESIGN: Clinical retrospective multicenter study. ANIMALS: 132 client-owned brachycephalic dogs. METHODS: 132 brachycephalic dogs with high-grade Brachycephalic Obstructive Airway Ayndrome (BOAS) and hypertrophic turbinates were treated with RFVTR as part of MLS of the upper airways. Intranasal obstruction was evaluated by computer tomography (CT) and antero-/retrograde rhinoscopy before and 6 months after RFVTR. The clinical records, the CT images and the rhinoscopy videos were reviewed and clinical evolution was evaluated using a standardized questionnaire. The data was scored semi-quantitatively. RESULTS: In this study, 132 patients were included for a follow-up period of 120 weeks. RFVTR resulted in minor complications, including serous nasal discharge within the first postoperative week in all dogs, and intermittent nasal congestion between 3-8 weeks after treatment in 24.3% of the patients. Rhinoscopy and CT follow-ups were available for 33 patients. Six months after treatment intranasal airspace was increased (p = 0.002) and the presence and overall amount of mucosal contact points was reduced (p = 0.039). CONCLUSION: MLS with RFVTR led to a significant reduction in turbinate volume at the 6-month follow-up examination and significant clinical improvement over a long-term period of 120 weeks. This suggests the viability of RFVTR as a turbinate-preserving treatment for intranasal obstruction in dogs with BOAS. CLINICAL SIGNIFICANCE: RFVTR is a minimally invasive turbinoplasty technique for intranasal obstruction in dogs with BOAS and can be included in MLS without increasing complication rates.

Levopositioned caudal vena cava and circumcaval left ureter with subsequent hydronephrosis and hydroureter in a dog.

The presentation and investigation of a levopositioned caudal vena cava, a rare congenital vascular abnormality seen mainly in Bernese Mountain Dogs, which resulted in ureteral compression, hydronephrosis and hydroureter. Surgical transection, transposition and anastomosis were performed to reposition the circumcaval ureter. A 19-month-old male neutered Bernese Mountain Dog was presented with a 13-month history of vague signs including intermittent abdominal pain, inappetence and diarrhoea, which were poorly responsive to medical management. Abdominal ultrasound revealed left-sided hydronephrosis and hydroureter. Further investigation included abdominal computed tomography and pre- and post-intravenous iodinated contrast, which revealed a levopositioned caudal vena cava with associated ureteral displacement to a circumcaval position, resulting in ureteral compression and proximal dilation affecting both the proximal ureter and the left kidney. The patient was also found to have concomitant gall bladder agenesis. Surgery was performed to transect, transpose and anastomose the ureter in a normal anatomical position, and the patient made an excellent clinical recovery. All gastrointestinal signs resolved within 2 weeks of surgery and remained resolved 12 months later. Follow-up ultrasound and pyelography were performed at 4-month post-surgery, revealing a mild improvement in the hydronephrosis and hydroureter. Although rare, circumcaval ureter should be considered a differential in dogs presenting with hydroureter and hydronephrosis, especially Bernese Mountain Dogs.

Imaging guided adrenalectomy with Indocyanine green fluorescence in a dog with a pheochromocytoma.

IMPORTANCE: This case report presents the successful surgical removal of a pheochromocytoma in a dog using indocyanine green (ICG) fluorescence imaging. CASE PRESENTATION: A 10-year-old, 6.87 kg, spayed female poodle was referred for an abdominal mass and eight episodes of vomiting. Computed tomography revealed masses in the spleen and left adrenal gland. Based on the plasma normetanephrine levels, the patient was diagnosed with pheochromocytoma. Subsequently, a total splenectomy and left adrenalectomy were performed. A dose of 5 mg/kg ICG was administered intravenously 24 h prior to surgery. Using ICG allowed visualization of tumor margins, aiding in complete resection and minimizing anesthesia-related risks. CONCLUSIONS AND RELEVANCE: No evidence of recurrence or metastasis has been observed for 12 months. To our knowledge, this is the first report of the surgical removal of a pheochromocytoma using intraoperative ICG imaging in veterinary medicine. This case highlights the efficacy of ICG fluorescence imaging as a valuable tool for the surgical management of adrenal tumors in veterinary medicine.

Computed tomographic reference ranges of intrathoracic caudal vena cava ratios in sedated adult dogs without cardiac, pulmonary, or hypovolemic disease.

BACKGROUND: Radiographic assessment of the intrathoracic caudal vena cava (CVC) is commonly used to evaluate hemodynamic status in veterinary patients without and with pulmonary, pericardial, or right-sided cardiac diseases. Many of these patients are now commonly evaluated with computed tomography (CT) in both emergency and referral settings. Traditional radiographic ratios in dogs, particularly the CVC height/aorta height (CVC/Ao) ratio, are often extrapolated to CT in order to determine if the CVC is normal in size. OBJECTIVES: The first goal of this retrospective study was to create an objective measurement method to evaluate the size of the CVC via CT. The second goal was to report normal CVC ratio values in both sagittal and transverse CT images. METHODS: The traditional lateral radiographic CVC ratios were extrapolated to similar ratios obtained from sagittal CT images in stable, sedated adult canine patients without known cardiac or pulmonary disease. Additionally, new methods of canine CVC ratios using transverse CT images were defined using vessel height and area. Mean, standard deviation, and 95% confidence intervals (CIs) of the CVC ratios in transverse and sagittal CT images were calculated to determine normal reference ranges. RESULTS: Ratio agreement from observers of different skill levels was moderate to excellent. Sagittal CT CVC/Ao mean was 1.07 ± 0.17 with a CI of 0.71.42. The mean and CI of transverse CT CVC/Ao height and area were 1.14 ± 0.27 and 0.781.44 and 1.36 ± 0.59 and 0.641.94, respectively. CONCLUSIONS: Application of normal sagittal and transverse CT ratio values in canine patients with and without hypotension, pulmonary, pericardial, or right-sided cardiac diseases is necessary to determine the clinical usefulness of these ratios.

Excision of a gastrointestinal stromal tumour in a dog using short-wave infrared fluorescence imaging and indocyanine green.

A 7-year-old castrated male Golden Retriever weighing 36.8 kg presented to the Veterinary Teaching Hospital with vomiting, anorexia and depression. After blood tests, radiographic, ultrasound and computed tomography examinations, a 7.85 × 5.90 × 8.75 cm mass was identified in the caecum. To visualise the tumour margin and improve the accuracy of tumour resection, intraoperative short-wave infrared imaging using indocyanine green was performed during surgery. An indocyanine green solution was injected intravenously as a bolus of 5 mg/kg 24 h before surgery. Tumour resection was performed with a 0.5 cm margin from the fluorescent-marked tissues. Histopathological examination revealed a diagnosis of a gastrointestinal stromal tumour (GIST) and the absence of neoplastic cells in the surgical margin, indicating a successful surgery. To our knowledge, this is the first case of a GIST resection in a dog using intraoperative short-wave infrared imaging.

Imaging findings in otitis media and resulting secondary lesions in dogs and cats - an image essay.

Over the past 2 decades, the increasing availability of computed tomography (CT) and magnetic resonance imaging (MRI) as well as the growing professional expertise have significantly improved the diagnostics of middle and inner ear diseases in dogs and cats. In answering some of the diagnostic questions, CT and MRT demonstrate equivalent performance. For most questions, however, there are differences in the diagnostic performance due to the physical imaging properties of the 2 modalities.CT is more sensitive in demonstrating involvement of the bulla wall and is more effective for detecting abnormal content within the tympanic bulla. In addition, with CT it is often easier to guide tissue samplings. On the other hand, structural changes of the soft tissues of the skull, head, meninges, brain, and nerves are not or only insufficiently detectable on CT images. MRI is clearly superior here. Therefore, MRI is essential for the characterization of materials inside the bulla cavity and for demonstrating the extent of any central spread of otitis media (OM).In this image essay, CT and MRI features of OM and resulting secondary lesions described in the literature are analyzed and summarized. Own image examples are used for illustration. Information on the etiology, pathogenesis, pathomorphology, and clinical signs important for understanding these changes are presented in concise descriptions.

Computed tomographic evaluation of portal vein indices in cats with the extrahepatic portosystemic shunts.

IMPORTANCE: The portal vein to aorta (PV/Ao) ratio is used to assess the clinical significance of extrahepatic portosystemic shunt (EHPSS). Previous studies using computed tomography (CT) were conducted in dogs but not in cats. OBJECTIVE: This study aimed to establish normal reference values for PV indices (PV/Ao ratio and PV diameter) in cats and determine the usefulness of these for predicting symptomatic EHPSS. METHODS: This study included 95 dogs and 114 cats that underwent abdominal CT. The canine normal (CN) group included dogs without EHPSS. The cats were classified into feline normal (FN, 88/114), feline asymptomatic (FA, 16/114), and feline symptomatic (FS, 10/114) groups. The PV and Ao diameters were measured in axial cross-sections. RESULTS: The group FN had a higher PV/Ao ratio than the group CN (p < 0.001). Within the feline groups, the PV indices were in the order FN > FA > FS (both p < 0.001). The mean PV diameter and PV/Ao ratio for group FN were 5.23 ± 0.77 mm and 1.46 ± 0.19, respectively. The cutoff values between groups FN and FS were 4.115 mm for PV diameter (sensitivity, 100%; specificity, 97.7%) and 1.170 for PV/Ao ratio (90%, 92.1%). The cutoff values between group FA and FS were 3.835 mm (90%, 93.8%) and 1.010 (70%, 100%), respectively. CONCLUSIONS AND RELEVANCE: The results demonstrated significant differences in PV indices between dogs and cats. In cats, the PV/Ao ratio demonstrated high diagnostic performance for symptomatic EHPSS. The PV diameter also performed well, in contrast to dogs.

Longitudinal analysis of echocardiographic and cardiac biomarker variables in dogs with atrial fibrillation: The optimal rate control in dogs with atrial fibrillation II study.

BACKGROUND: Rate control (RC; meanHRHolter ≤ 125 bpm) increases survival in dogs with atrial fibrillation (AF). The mechanisms remain unclear. HYPOTHESIS/OBJECTIVES: Investigate echocardiographic and biomarker differences between RC and non-RC (NRC) dogs. Determine if changes post-anti-arrhythmic drugs (AAD) predict successful RC in subsequent Holter monitoring. Evaluate if early vs late RC affects survival. ANIMALS: Fifty-two dogs with AF. METHODS: Holter-derived mean heart rate, echocardiographic and biomarker variables from dogs receiving AAD were analyzed prospectively at each re-evaluation and grouped into RC or NRC. The primary endpoint was successful RC. Between group comparisons of absolute values, magnitude of change from admission to re-evaluations and end of study were performed using Mann-Whitney tests or unpaired t-tests. Logistic regression explored variables associated with inability to achieve RC at subsequent visits. Kaplan-Meier survival analysis was used to compare survival time of early vs late RC. RESULTS: At visit 2, 11/52 dogs were RC; at visit 3, 14/52 were RC; and at visit 4, 4/52 were RC. At the end of study, 25/52 remained NRC. At visit 2, both groups had increased cardiac dimensions, but NRC dogs had larger dimensions; biomarkers did not differ. At the end of study, RC showed decreased cardiac dimensions and end-terminal pro-brain natriuretic peptide (NT-proBNP) compared with NRC. No variables were useful at predicting RC success in subsequent visits. Survival analysis found no differences between early vs late RC. CONCLUSIONS AND CLINICAL IMPORTANCE: The RC dogs had decreased cardiac dimensions and NT-proBNP, suggesting HR-mediated reverse-remodeling might benefit survival, even with delayed RC achievement. Pursuit of RC is crucial despite initial failures.

Assessment of retinal atrophy in mixed breed dogs using spectral domain optical coherence tomography (SD-OCT) and electroretinography.

The aim of the study was to characterize retinal atrophy (RA) with progressive retinal atrophy symptoms in mixed breed dogs using ophthalmoscopy, spectral domain optical coherence tomography (SD-OCT) and electroretinography (ERG).The study was performed on 13 mixed breed dogs affected by retinal atrophy (11 males and 2 females that were 1.5-14 years old). Depending on the advancement of RA, SD-OCT examinations identified retinal abnormalities ranging from layer disorganisation to advanced atrophy. The most advanced RA occurred ventral to the optic disc. Total retinal thickness in both eyes (mean ± SD) was lower in dogs with RA compared to controls dorsally (77.7 ± 39.5 µm vs 173.5 ± 13.3 µm), ventrally (33.4 ± 29.9 µm vs 139.5 ± 10.8 µm), nasally (65.0 ± 34.5 µm vs 163.9 ± 11.0 µm) and temporally (61.8 ± 41.7 µm vs 171.9 ± 11.1 µm) to the optic disc. In dogs with locally normal architecture of inner retina, loss of definition of outer retinal layers occurred in many regions. Dark and light-adapted ERGs were reduced in 2 dogs with RA and were unrecordable in 11 dogs. Lesions evident in SD-OCT scans of mixed breed dogs affected with retinal atrophy initially appear ventrally to the optic disc and ventro-dorsally in advanced RA. In all mixed breed dogs with retinal atrophy, clinical signs and SD-OCT results correlate with ERG findings.

Frequency of low-dose dexamethasone suppression test (LDDST) response patterns and their correlation with clinicopathologic signs in dogs suspected of having Cushing's syndrome: A retrospective study.

A retrospective cross-sectional study was conducted to assess the frequency of low-dose dexamethasone suppression test (LDDST) patterns in canine patients that had clinicopathologic signs consistent with Cushing's syndrome (CS). Medical records for patients of interest (N = 128) were reviewed between January 2014 and December 2020 to analyse and classify LDDST results based upon the following patterns: lack of suppression, partial suppression, complete suppression, escape, or inverse. Complete suppression, lack of suppression, partial suppression, escape, and inverse patterns were identified in 39.1%, 31.2%, 14.1%, 10.1% and 5.5% of cases respectively. LDDST results were also evaluated with respect to clinical signs, serum alkaline phosphatase (ALP) activity, urine specific gravity (USG) and adrenal ultrasonographic findings. There was no association between LDDST patterns and clinical signs (p = 0.11), increased ALP (p = 0.32), USG (p = 0.33) or adrenal ultrasonographic findings (p = 0.19). In all dogs that demonstrated complete suppression or an inverse pattern, CS was excluded by the attending clinician. The diagnosis of CS was also excluded without further exploration in 23.1%, 7.5% and 5.6% of dogs that demonstrated an escape pattern, lack of suppression and partial suppression pattern, respectively. These results suggest that the clinical significance of LDDST patterns, particularly escape and inverse patterns, are misunderstood by some clinicians, leading them to prematurely exclude the diagnosis of CS.

Effect of cranial tibial artery laceration on radiographic bone healing and perioperative complications in dogs undergoing tibial plateau leveling osteotomy.

During tibial plateau leveling osteotomy (TPLO), the laceration of the cranial tibial artery (LCTA) may occur, and the ligation of the cranial tibial artery might lead to impaired blood supply to the osteotomy site. The present case-control study aimed to evaluate the effect of LCTA on TPLO healing and the occurrence of perioperative complications. The incidence and predisposing factors to LCTA were also investigated. Fourteen cases experiencing LCTA were retrospectively enrolled from medical records of two veterinary teaching hospitals (LCTA group), whereas 28 randomly selected TPLOs that did not experience LCTA were included in the control group. Signalment data, proximal tibial epiphysis conformation, osteotomy features, perioperative complications, and bone healing were compared between the two groups. Bone healing was evaluated using the modified radiographic union scale for tibial fracture and the visual analog scale. The mean incidence was 9.6%. Bodyweight was significantly higher in the LCTA group compared to the control group (P = 0.009). Dogs belonging to the LCTA groups were significantly younger (P = 0.01). Intraoperative hypotension was significantly overreported in the LCTA group (P = 0.0001). None of the other variables differed significantly between the two groups. Dogs' size seems to be a predisposing factor, with dogs weighing >15 kg having 22 times more chance of experiencing LCTA. Due to the well-developed collateral blood supply of the canine hindlimb, LCTA and the closure of the cranial tibial artery did not appear to delay the radiographic bone healing or affect the incidence of perioperative complications.

Differences in normal nasal computed tomography findings in different dog breeds.

Background: Computed tomography (CT) is the gold standard for diagnosing canine nasal diseases. However, it cannot easily detect minor abnormalities in inflammatory diseases because they are not accompanied by obvious morphological changes. Aim: The present study aimed to compare the differences in normal CT findings of turbinate structure and mucosa between breeds to establish criteria for CT diagnosis of inflammatory diseases of the nasal cavity. Methods: CT data from 77 dogs of 5 breeds without nasal diseases were retrospectively studied. The nasal air percentage, which reflects the volume of the nasal turbinate structure and mucosa, was measured. The nasal turbinate mucosa was measured for contrast enhancement reflecting blood flow. Measurements were performed in the ventral and ethmoid turbinate (ET) regions. Comparisons were made between breeds and sections. Results: The air percentage in the ventral and ET regions was significantly different between breeds. Contrast enhancement was significantly different between breeds only in the ET. Moreover, different breeds had different correlations between body weight, age, nose length, and air percentage. Conclusion: In this study, reference values for normal CT findings of the nasal structure and mucosa were obtained, taking into account the breed, measurement section, and patient factors. The results showed that the volume of the turbinate structure and contrast enhancement of nasal mucosa differed depending on the breed. The measured values also differed depending on the cross-sections and patient factors.

CT findings in seven dogs with perforating wooden skewer foreign bodies from the gastrointestinal tract.

Background: Perforating foreign bodies from the gastrointestinal tract, such as wooden skewers, are reported in the small animal literature producing inflammatory/infectious lesions in the thorax, abdomen, and musculoskeletal system, which can be life-threatening in some instances. Several imaging modalities have been used, and advanced imaging techniques have shown a great advantage in its diagnosis and pre-surgical planning. Aim: The objective of this study is to describe the computed tomographic findings in a group of seven medium to large breed dogs with perforating wooden skewers and foreign bodies migrated from the gastrointestinal tract. Methods: The medical records database was searched for dogs with a suspected diagnosis of a perforating wooden foreign body migrated from the gastrointestinal tract in which a computed tomographic study was performed. Signalment, history, and clinicopathological findings (when available) were retrieved, and the computed tomographic studies were reviewed. Results: Clinical signs vary depending on the anatomical regions affected through the perforating pathway. All foreign bodies were identified and showed a median attenuation of 79 HU, with the most common localization being the stomach followed by the jejunum. Peritoneal fat stranding surrounding the perforation site was the most frequent computed tomographic finding. The presence of peritoneal free fluid and/or gas was uncommon. Pleural effusion, pulmonary perforation, and pneumothorax were present in most of the cases with the foreign body traversing the pleural space. Pulmonary cavitary lesions were always reported when the ending tip of the wooden skewer was within the pulmonary parenchyma. Soft tissue abscessation was recognized in all cases where the ending tip was lodged in muscular or subcutaneous tissues. Conclusion: Findings supported the variability of the secondary lesions caused by this type of foreign body and the utility of computed tomography in their recognition, as well as in the identification of the wooden skewer.

Assessment of tumor hypoxia in spontaneous canine tumors after treatment with OMX, a novel H-NOX oxygen carrier, with [18F]FMISO PET/CT.

BACKGROUND: Hypoxia is a detrimental factor in solid tumors, leading to aggressiveness and therapy resistance. OMX, a tunable oxygen carrier from the heme nitric oxide/oxygen-binding (H-NOX) protein family, has the potential to reduce tumor hypoxia. [18F]Fluoromisonidazole ([18F]FMISO) positron emission tomography (PET) is the most widely used and investigated method for non-invasive imaging of tumor hypoxia. In this study, we used [18F]FMISO PET/CT (computed tomography) to assess the effect of OMX on tumor hypoxia in spontaneous canine tumors. RESULTS: Thirteen canine patients with various tumors (n = 14) were randomly divided into blocks of two, with the treatment groups alternating between receiving intratumoral (IT) OMX injection (OMX IT group) and intravenous (IV) OMX injection (OMX IV group). Tumors were regarded as hypoxic if maximum tumor-to-muscle ratio (TMRmax) was greater than 1.4. In addition, hypoxic volume (HV) was defined as the region with tumor-to-muscle ratio greater than 1.4 on [18F]FMISO PET images. Hypoxia was detected in 6/7 tumors in the OMX IT group and 5/7 tumors in the OMX IV injection group. Although there was no significant difference in baseline hypoxia between the OMX IT and IV groups, the two groups showed different responses to OMX. In the OMX IV group, hypoxic tumors (n = 5) exhibited significant reductions in tumor hypoxia, as indicated by decreased TMRmax and HV in [18F]FMISO PET imaging after treatment. In contrast, hypoxic tumors in the OMX IT group (n = 6) displayed a significant increase in [18F]FMISO uptake and variable changes in TMRmax and HV. CONCLUSIONS: [18F]FMISO PET/CT imaging presents a promising non-invasive procedure for monitoring tumor hypoxia and assessing the efficacy of hypoxia-modulating therapies in canine patients. OMX has shown promising outcomes in reducing tumor hypoxia, especially when administered intravenously, as evident from reductions in both TMRmax and HV in [18F]FMISO PET imaging.

The echocardiographic pulmonary to left atrial ratio: A noninvasive variable for the hemodynamic classification of pulmonary hypertension in dogs.

BACKGROUND: Hemodynamic classification of pulmonary hypertension (PH) has important clinical implications. However, only a few echocardiographic variables have been used to hemodynamically classify PH in dogs. OBJECTIVE: To evaluate the echocardiographic pulmonary to left atrial ratio index (ePLAR) in dogs with PH. ANIMALS: Forty-six dogs with intermediate to high probability of PH. METHODS: Cross-sectional study. Variables were compared between dogs with precapillary PH [PrePH (n = 24)] vs postcapillary PH [PostPH (n = 22)], and with combined PH [CombPH (n = 14)] vs isolated PH [IsoPH (n = 8)] using the t-, Mann-Whitney, Pearson's Chi, or Fisher's exact test. The receiver operating characteristic curve and Youden index were used to identify the optimal ePLAR cutoff value to differentiate among the groups, intraclass correlation coefficients (ICC) were used to determine the reliability of measurements. RESULTS: The mean (SD) ePLAR of the PrePH was higher than that of the PostPH group [0.36 (0.13) vs 0.26 (0.09), respectively; P = .005]. The median (interquartile range) ePLAR of the CombPH was higher than that of the IsoPH subgroup [0.29 (0.24-0.38), vs 0.20 (0.16-0.23), respectively; P = .001]. The best cutoff value of ePLAR for identifying IsoPH was <0.245 [AUC at cutoff point = 0.86; sensitivity (95% confidence interval [CI]) = 0.71 (0.47-0.95); specificity (95% CI) = 1 (0.76-1)]. The ICC analysis indicated a high degree of reliability. CONCLUSIONS AND CLINICAL IMPORTANCE: ePLAR can be considered a valid noninvasive variable to hemodynamically classify PH in dogs with an intermediate to high probability of PH. Assessment of ePLAR can be useful in the therapeutic management of PH in dogs.

Clinicopathological and diagnostic imaging findings in a dog with neurocandidiasis.

Neurocandidiasis is systemic candidiasis with central nervous system involvement. This case report describes the clinical presentation, diagnostic test results, and histopathology of a dog with neurocandidiasis. A 3-year-old German shepherd dog was presented for a 3-day history of abnormal mentation, neck pain, and ataxia. Magnetic resonance imaging (MRI) scan of the brain revealed multifocal, small, round, intra-axial lesions within the forebrain. Examination of the cerebrospinal fluid revealed severe neutrophilic inflammation. Extensive testing for infectious diseases was negative. The dog was administered immunosuppressive doses of corticosteroids. The dog's clinical signs improved transiently but got worse 12 days after starting the treatment. Repeat MRI scan revealed multiple, intra-axial, target-like nodular lesions scattered throughout the brain parenchyma. In the temporal muscles, nodules were seen. Cytology of the fine needle aspirates of the nodules in the temporal muscles revealed a neutrophilic inflammation with hyalohyphomycosis. Postmortem examination was compatible with a severe systemic fungal infection. Candida albicans was isolated from the brain, kidney, and heart.