Hydrops fetalis caused by a complex congenital heart defect with concurrent hypoplasia of pulmonary blood vessels and lungs visualized by micro-CT in a French Bulldog.

BACKGROUND: Hydrops fetalis (HF) is fluid accumulation in fetus body cavities and subcutaneous tissue. The condition has been described in various farm and companion animal species, including dogs. Most of cases result from a heart defect. Exact nature of this defect is rarely clarified. CASE PRESENTATION: A newborn, male French bulldog puppy with severe HF underwent a full anatomopathological examination to diagnose the primary cause of HF. Based on the anatomopathological examination, fetal ultrasound, and micro-computed tomography, transposition of the great arteries with hypoplasia of the ascending aorta, aortic arch interruption, ostium secundum atrial septal defect, severe tricuspid valve dysplasia, as well as hypoplasia of pulmonary vessels and lungs were diagnosed. CONCLUSIONS: This is the first report of HF caused by severe, complex congenital heart defects with concurrent pulmonary vessel and lung hypoplasia.

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.

Diagnostic value of ultrasonography in identifying unilateral ovarian luteoma in a dog.

Background: Diagnosing ovarian tumors in dogs can be challenging since the clinical symptoms are often generic. The present case report underscores a rare case in which a suspected unilateral ovarian tumor in a dog was initially identified using ultrasonography and subsequently confirmed to be a luteoma through postoperative histopathology. Case Description: An 8-year and 6-month-old female Maltese dog presented with a 10-day history of vulvovaginal bleeding, hematuria, and decreased appetite. Physical examination revealed only vaginal bleeding, with no other abnormalities. Laboratory examinations showed no abnormalities, while abdominal radiography revealed the presence of cystic calculi as the sole abnormality. Abdominal ultrasound revealed an enlarged right ovary with regular contour and echogenicity, featuring unusual cystic components surrounding the right ovarian parenchyma. Furthermore, irregular thickening with multiple cystic lesions was observed in the endometrial wall of the bilateral uterine horns, indicative of cystic endometrial hyperplasia. Ultrasonographic findings suggested unilateral right ovarian disease. During ovariohysterectomy, the right ovary was slightly larger than the left ovary and adhered to the surrounding mesenteric fat layer and right pancreatic parenchyma. Histopathological examination confirmed the diagnosis of luteoma in the right ovary. Three days after surgery, the patient's clinical signs exhibited complete improvement, with the return of normal appetite. Conclusion: This case report highlights a rare diagnosis of unilateral ovarian luteoma based on mild ultrasonographic abnormalities, which was ultimately confirmed on histopathological examination.

Findings of an Extraluminal Leiomyosarcoma of the Urinary Bladder in a Dog.

A 9 yr old male miniature poodle presented with acute diarrhea, vomiting, and a distended abdomen. A large and firm mass was palpated in the caudal abdomen. Radiography showed a large soft-tissue mass in the mid ventral abdomen. The mass was mildly contrast-enhancing and in contact with the right cranial aspect of the bladder on computed tomography. The mass was heterogeneous with minimal blood flow on Doppler examination. Surgery confirmed its origin of the urinary bladder, and it was diagnosed leiomyosarcoma on pathology. This is the first report of extraluminal leiomyosarcoma of the bladder wall with imaging characteristics using various modalities.

Clinical outcomes of 20 brachycephalic dogs with thoracolumbar spinal deformities causing neurological signs treated with spinal stabilization using 3D-printed patient-specific drill guides.

OBJECTIVE: To describe the clinical outcomes for pugs and French bulldogs with congenital vertebral malformations, undergoing thoracolumbar spinal stabilization surgery using 3D-printed patient-specific drill guides. To evaluate the accuracy of pedicle screw placement in this group of dogs. STUDY DESIGN: Retrospective descriptive study. ANIMALS: Twenty dogs (12 pugs and eight French bulldogs). METHODS: Medical records searched between August 2018 and March 2021 for pugs and French bulldogs diagnosed with congenital vertebral abnormalities via magnetic resonance imaging (MRI) scan and computed tomography (CT) scan causing T3-L3 myelopathy signs that underwent spinal stabilization surgery using 3D-printed patient-specific drill guides followed by a postoperative CT scan. The short-term outcome was based on the neurological grade (modified Frankel score-MFS) on the day after surgery, day of discharge, and at the follow-up examination at 4 to 6 weeks after surgery. The mid-term outcome was obtained via an online questionnaire (or direct examination in one case). RESULTS: Twenty dogs met the inclusion criteria (19/20 grade 2 MFS, 1/20 grade 4 MFS). No complications were reported in the immediate postoperative period and optimal pedicle screw placement was obtained in 169/201 of screws. Twenty-four hours after surgery 16/20 dogs displayed an unchanged neurological grade. Short-term outcomes revealed a static (17/20) or improved (2/20) neurological grade. Ten owners participated in the online questionnaire. All patients were reported to be ambulatory; however, 7/10 dogs displayed abnormal gait. Neurological signs had remained static (6/10) or improved (3/10) in comparison with the dogs' preoperative status at a median of 883.5 days from the surgery. CONCLUSION: Dogs in this study had a favorable short-term outcome and mid-term outcome evaluation revealed a static/improved neurological status. CLINICAL SIGNIFICANCE: Thoracolumbar spinal stabilization surgery using 3D-printed patient-specific drill guides showed a favorable outcome in brachycephalic breeds affected by vertebral deformities.

Computed tomographic features of canine intracranial and jugular foraminal masses involving the combined glossopharyngeal, vagus, and accessory nerve roots.

A chronic cough, gag, or retch is a common presenting clinical complaint in dogs. Those refractory to conservative management frequently undergo further diagnostic tests to investigate the cause, including CT examination of their head, neck, and thorax for detailed morphological assessment of their respiratory and upper gastrointestinal tract. This case series describes five patients with CT characteristics consistent with an intracranial and jugular foraminal mass of the combined glossopharyngeal (IX), vagus (X), and accessory (XI) cranial nerves and secondary features consistent with their paresis. The consistent primary CT characteristics included an intracranial, extra-axial, cerebellomedullary angle, and jugular foraminal soft tissue attenuating, strongly enhancing mass (5/5). Secondary characteristics included smooth widening of the bony jugular foramen (5/5), mild hyperostosis of the petrous temporal bone (3/5), isolated severe atrophy of the ipsilateral sternocephalic, cleidocephalic, and trapezius muscles (5/5), atrophy of the ipsilateral thyroarytenoideus and cricoarytenoideus muscles of the vocal fold (5/5), and an ipsilateral "dropped" shoulder (4/5). Positional variation of the patient in CT under general anesthesia made the "dropped" shoulder of equivocal significance. The reported clinical signs and secondary CT features reflect a unilateral paresis of the combined cranial nerves (IX, X, and XI) and are consistent with jugular foramen syndrome/Vernet's syndrome reported in humans. The authors believe this condition is likely chronically underdiagnosed without CT examination, and this case series should enable earlier CT diagnosis in future cases.

Surgical management of urethral obstruction secondary to perineal liposarcoma in a dog: a case report.

BACKGROUND: Swelling of the perineal region in male dogs is most commonly caused by a perineal hernia. Clinical signs associated with perineal hernia are constipation, tenesmus or stranguria. This case report documents a rare cause of perineal swelling created by the growth of a malignant tumour leading to urethral obstruction and subsequent stranguria. CASE PRESENTATION: An 11-year-old neutered male German Shepherd was presented for swelling in the perineal region and stranguria for three days. Complete blood count and serum biochemistry were unremarkable. Ultrasound revealed a heterogeneous mass in the perineal region. Retrograde urethrography showed a severe narrowing of the urethra caudal to the pelvis. A fine-needle aspirate of the mass was highly suspicious for liposarcoma. Staging was performed by computed tomography (CT) of the thorax and abdomen. Total penile amputation in combination with pubic-ischial pelvic osteotomy, transposition of the remaining urethra through the inguinal canal, V-Y-plasty cranial to the prepuce and preputial urethrostomy were performed to remove the tumour. Histopathology confirmed a well-differentiated liposarcoma with complete histological margins. Six months after the surgery the dog was doing well and there were no signs indicating local tumour recurrence. CONCLUSIONS: Wide surgical excision is generally recommended for soft tissue sarcomas, however this is sometimes not feasible for large tumours. In the case reported here, tumour resection was achieved by a combination of several surgical techniques with a good clinical outcome.

Intracranial invasion of a mast cell tumour in a dog: A case report and review of the literature.

An 11-year-old, female-neutered beagle was presented with a growing soft tissue mass arising within the deep tissues of the left cranial cervical region. At presentation, facial asymmetry was evident along with palpable lymphadenomegaly. Magnetic resonance imaging demonstrated a locally invasive cervical mass with intracranial invasion through focal osteolysis of the occipital bone. After antihistamine administration, cytology confirmed mast cell tumour (MCT) with metastasis to local lymph nodes and liver. The owner chose to pursue lomustine and prednisolone, which were dispensed, but, before home administration, prolonged seizures/status epilepticus occurred prompting euthanasia. Postmortem examination confirmed a high-grade MCT associated with, and infiltrating through, muscle, calvarium, dura mata, leptomeninges and the underlying brain. We present the clinical, imaging, and pathological findings of an unprecedented case of extracranial MCT tumour causing osteolysis of an imperforate flat bone (occipital bone) and intracranial invasion.

Bleb characteristics assessed by ultrasound biomicroscopy correlate with intraocular pressure after Ahmed glaucoma valve surgery in dogs.

OBJECTIVE: To assess the characteristics of blebs formed after Ahmed glaucoma valve (AGV) surgery in dogs using ultrasound biomicroscopy (UBM) and to analyze their correlation with postoperative intraocular pressure (IOP). ANIMALS: 16 eyes (13 dogs) were diagnosed with primary angle-closure glaucoma and were followed up after AGV surgery from June 2021 to September 2023. METHODS: In this prospective study, UBM examinations were performed to assess bleb characteristics, including bleb wall thickness and reflectivity. IOP at the time of UBM imaging and the duration from AGV surgery to UBM imaging were recorded. Histological examination of an enucleated eye removed due to uncontrolled IOP leading to blindness was also conducted. RESULTS: A significant correlation was observed between IOP and relative reflectivity (Pearson r = 0.60; P = .01), and a negative correlation was observed between bleb wall thickness and relative reflectivity (Pearson r = -0.72; P = .002). No significant correlation was observed between the duration from AGV surgery to UBM imaging and either bleb wall thickness or relative reflectivity, respectively. Histological examination of the enucleated eye revealed collagen-rich fibrous encapsulation of the bleb wall, including myofibroblasts that exhibited positive α-smooth muscle actin immunostaining. CLINICAL RELEVANCE: In dogs that underwent AGV surgery, less dense, thick-walled blebs on UBM tended to maintain IOP within the normal range. However, denser, thinner-walled blebs showed IOP levels above the normal range despite the use of antiglaucoma medications. UBM is a useful tool for evaluating bleb characteristics and their influence on IOP regulation after AGV surgery in dogs.

Atypically located accessory splenic hemangiosarcoma in a Dog: Diagnostic value of triple-phase computed tomography.

A 10-year-old Cocker spaniel presented with lethargy. Triple-phase computed tomography was obtained with a contrast test bolus at the level of porta hepatis, which revealed a right lower abdominal mass. The mass was not connected to other abdominal organs; however, a linear structure was observed connecting the splenic hilum to the mass, which was suspected to be the feeding vessel. The arterial phase image was obtained again with a contrast bolus at the level of the celiac artery. A prominent contrast-enhanced feeding artery originating from the splenic artery to the mass was observed. Histopathology confirmed an accessory splenic hemangiosarcoma.

Cervical intervertebral disc disease in 307 small-breed dogs (2000-2021): Breed-characteristic features and disc-associated vertebral instability.

OBJECTIVE: To evaluate the breed-characteristic features of cervical intervertebral disc disease (C-IVDD) and associated vertebral instability in small-breed dogs and to present the concept of intervertebral disc degeneration and associated instability stage, method of diagnosis, treatment and outcomes. ANIMALS: In total, 307 client-owned dogs with C-IVDD treated with spinal cord decompression with or without vertebral stabilization (2000-2021). METHODS: Information on age, sex, affected sites, stabilized sites, diagnostic methods for vertebral instability and outcomes were retrieved. The patient's age, affected sites (cranial vs caudal discs), and frequency of vertebral stabilization were compared in six CD and five NCD breed. Multivariable analyses of the chondrodystrophic (CD) vs non-CD (NCD) groups, and vertebral stabilization (dogs stabilized vs dogs not stabilized) were performed. RESULTS: In total, 222 (72.3%) and 77 (25.1%) were CD and NCD breeds, respectively. Vertebral instabilities were diagnosed based on the survey radiographs with computed tomography/magnetic resonance imaging (n = 2), dynamic myelography (n = 29), intraoperative spinal manipulation (n = 11) or second surgery in dogs with persistent postoperative paraspinal pain (n = 3). Of these dogs, 295 (96.1%) recovered (median follow-up: 8.5 [range, 1-119] months). Significant differences in age, affected sites and frequency of stabilization were noted among the breeds. Older age and frequent vertebral stabilization were the associated factors for the NCD breed dogs. Male dogs, caudal discs affected (C5-T1) and the NCD breed dogs were risk factors for the dogs with vertebral stabilization. CONCLUSION: Vertebral stabilization is indicated for small-breed dogs with cervical disc-associated vertebral instability.

Uterine horn intussusception in immediate post-partum in a Pomeranian Spitz dog.

A 2-year-old Pomeranian-Spitz dog (5.8 kg) was admitted with symptoms of uterine prolapse and lethargy 1 day after whelping three puppies. The prolapsed uterus was corrected, but the next day, prolapse reoccurred. To fix the cervix to the abdominal wall, the dog underwent a surgery operation where intussusception in the left horn of the uterus was found. Ovariohysterectomy was performed as the treatment of choice. The diagnosis of intussusception is challenging, and exploratory laparotomy is the reliable diagnostic approach. Although uterine intussusception is rare, it should be one of the important considerations in dogs within the post-partum period.

Surgical treatment and outcome of haematomyelia with a traumatic cause in a dog and a cat.

Two surgically treated haematomyelia cases were documented. One dog and one cat were presented for acute progressive paraplegia following a fall from height incident. Neurological examinations suggested a L4-S3 myelopathy in both cases. Radiography and magnetic resonance imaging in both cases revealed no fracture or subluxation of the spine, but well-defined intramedullary mass lesions in lower lumbar regions compatible with haemorrhage and haematoma formation. Exploratory surgeries were performed over the lesions. Dark-red friable masses were removed via myelotomy. Histopathological examinations revealed organizing haematomas at the acute to subacute stage. Postoperatively, both cases improved and regained ambulation. The dog walked normally but remained urinary and faecal incontinent 9 months after the surgery. The cat was continent and ambulatory with a paraparetic gait 5 months after the surgery. In both cases, the outcomes and the patients' quality of life were considered satisfactory by the owners.

Successful surgical attenuation of portosystemic shunt in a dog with imaging-diagnosed portal vein aplasia.

An 8-month-old female Maltese dog was referred for examination with a history of circling, dullness, and drooling. Serum biochemical analysis revealed hyperammonemia, with microhepatica observed on radiography. Computed tomography angiography revealed a portosystemic shunt originating from the right gastric vein and inserting into the prehepatic caudal vena cava. Portal blood flow to the liver was not observed. Based on computed tomography angiography, the dog was tentatively diagnosed with portosystemic shunt with portal vein aplasia. An exploratory laparotomy was done to obtain a definitive diagnosis. The dog had no subjective clinical signs of portal hypertension during a temporary occlusion test of the portosystemic shunt. A thin-film band was placed around the portosystemic shunt to achieve partial attenuation. There was no evidence of hepatic encephalopathy in the long term after surgery, and the dog's liver volume increased over time. Computed tomography angiography at 6 mo after surgery identified well-visualized intrahepatic portal branches. Key clinical message: We inferred that a direct occlusion test is a reliable diagnostic technique that overcomes the limitations of diagnostic imaging methods, including computed tomography angiography, and is a good technique for determining whether surgical attenuation is possible in dogs with suspected portal vein aplasia.

Atténuation chirurgicale réussie d'un shunt porto-systémique chez un chien avec une aplasie de la veine porte diagnostiquée par imagerie. Une femelle bichon maltais âgée de 8 mois a été référée pour examen avec une histoire de tournis, apathie et salivation excessive. L'analyse biochimique du sérum a révélé une hyperammionémie, avec un petit foie observé lors des radiographies. Une angiographie par tomodensitométrie a révélé un shunt porto-systémique prenant son origine de la veine gastrique droite et s'insérant dans la veine cave caudale pré-hépatique. Le flot sanguin porte au foie n'était pas observé. Sur la base de l'angiographie par tomodensitométrie, un diagnostic présumé de shunt porto-systémique avec aplasie de la veine porte a été émis. Une laparotomie exploratoire a été effectuée afin d'obtenir un diagnostic définitif. Le chien ne présentait pas de signe clinique subjectif d'hypertension portale durant un test d'occlusion temporaire du shunt porto-systémique. Une bande de film mince a été placée autour du shunt porto-systémique pour causer une réduction partielle. Il n'y avait aucune évidence d'encéphalopathie hépatique à long terme après la chirurgie, et le volume du foie du chien a augmenté dans le temps. Une angiographie par tomodensitométrie effectuée 6 mo après la chirurgie a permis de bien visualiser des branches portes intra-hépatiques.Message clinique clé :Nous avons déduit qu'un test d'occlusion est une technique diagnostique fiable qui surpasse les limites des méthodes d'imagerie diagnostique, incluant l'angiographie par tomodensitométrie, et est une bonne technique pour déterminer si une réduction chirurgicale est possible chez des chiens chez qui on soupçonne une aplasie de la veine porte.(Traduit par Dr Serge Messier).

Small intestinal obstruction secondary to kinetic sand ingestion in a dog.

Objective: To describe a case of small intestinal obstruction secondary to kinetic sand ingestion in a dog. Animal: An 11-year-old neutered male shih tzu dog with a 2-day history of anorexia. Procedure: Abdominal radiographs revealed a small intestinal bowel loop dilated with radiopaque material, consistent with sand ingestion. The dog's only sand exposure was to kinetic sand. After 8 h of medical management, radiographs were consistent with a small intestinal obstruction. Results: The dog underwent exploratory laparotomy, which revealed distal jejunal and ileal distention with palpable soft foreign material that could not be milked into the colon. The sand was removed through a single enterotomy. The dog was discharged 4 d after surgery. Conclusion and clinical relevance: The hydrophobic properties of kinetic sand may make it more likely than regular sand to cause intestinal obstruction that requires surgery. With the increasing popularity and availability of kinetic sand for domestic use, clinicians should have a high index of suspicion for kinetic sand impaction and secondary intestinal obstruction.

Obstruction du petit intestin à la suite de l'ingestion de sable à modeler (Kinetic Sand) chez un chien. Objectif: Description d'un cas d'obstruction du petit intestin secondaire à l'ingestion de sable à modeler chez un chien. Animal: Chien shih tsu mâle castré âgé de 11 ans avec une historique d'anorexie depuis 2 jours. Procédure: Des radiographies abdominales ont révélé une anse du petit intestin dilatée avec du matériel radio-opaque, compatible avec une ingestion de sable. Une exposition à du sable à modeler était la seule exposition connue pour ce chien. Après 8 h de gestion médicale, les radiographies étaient compatibles avec une obstruction du petit intestin. Résultats: Une laparotomie exploratoire a révélé une distension du jéjunum distal et de l'iléon avec du matériel étranger mou palpable qui ne pouvait être transité dans le côlon. Le sable a été retiré à la suite d'une entérotomie simple. Le chien a obtenu sont congé médical 4 j après la chirurgie. Conclusion et signification clinique: Les propriétés hydrophobes du sable à modeler le rendent plus propice que le sable régulier à causer une obstruction intestinale et de nécessiter une chirurgie. Avec la popularité et disponibilité grandissante du sable à modeler pour usage domestique, les cliniciens devraient avoir un degré élevé de suspicion pour l'impaction par le sable à modeler et l'obstruction intestinale secondaire.(Traduit par Dr Serge Messier).

Relationship between clinical parameters and malformations in dogs diagnosed with atlanto-axial instability.

Atlanto-axial instability is a common disease that affects toy-breed dogs. Most cases of atlanto-axial instability are congenital. Furthermore, patients with atlanto-axial instability are predisposed to other concurrent diseases. Therefore, this study aimed to retrospectively determine the presence of concurrent diseases in cases with atlanto-axial instability using imaging data and analyze the relationship between clinical parameters and the incidence of complex malformations. The clinical data and imaging findings of 41 toy-breed dogs diagnosed with atlanto-axial instability were analyzed using their medical records and imaging data. Occipital dysplasia (17/27), atlanto-occipital overlapping (22/34), dens dysplasia (27/41), Chiari-like malformation (8/34), syringomyelia (5/34), lateral ventricular enlargement (20/36), and intracranial arachnoid cyst (5/35) were observed in patients with atlanto-axial instability. The body weight of the patients in the groups with atlanto-occipital overlapping and lateral ventricular enlargement was lower than that of those in the groups without these diseases (1.78 ± 0.71 vs 2.71 ± 1.15 kg, P = 0.0269, 1.60 ± 0.40 vs 2.75 ± 1.08 kg, P = 0.001, respectively). Furthermore, when the correlation between the total number of concurrent diseases and the age at onset and body weight was examined, it became clear that lower body weight was associated with the incidence of a greater number of concurrent diseases. Thus, the findings of this study suggest that toy-breed dogs are more likely to present with complex malformations and should be evaluated carefully with additional examinations and treatment methods.

Relationship between syringomyelia and myxomatous mitral valve disease in Cavalier King Charles spaniels.

BACKGROUND: Syringomyelia (SM) and myxomatous mitral valve disease (MMVD) are highly prevalent in Cavalier King Charles spaniels (CKCS). Cardiac status in CKCS with and without SM is currently unknown. OBJECTIVES: To investigate the association between SM and MMVD severity in CKCS and CKCS with SM with and without clinical signs of SM. ANIMALS: Fifty-five CKCS: 40 with SM (22 symptomatic and 18 asymptomatic) and 15 without SM. METHODS: A combined retrospective and prospective study. MRI and echocardiography were used to diagnose SM and MMVD, respectively. The association between SM and MMVD severity (left ventricle internal diameter in diastole normalized to bodyweight [LVIDDN] and left atrium to aortic ratio [LA/Ao]) were tested using multivariable linear regression analysis adjusting for sex and age. RESULTS: Overall, no significant difference in LVIDDN and LA/Ao was found between CKCS with or without SM. However, CKCS with symptomatic SM had significantly smaller LVIDDN (1.45 [1.30-1.50]) (median [IQR]) and LA/Ao (1.20 [1.10-1.28]) compared to CKCS with asymptomatic SM (1.60 [1.50-1.90] and 1.40 [1.20-1.75]) as well as CKCS without SM (0.24 [0.03-0.45] and 0.30 [0.05-0.56]) (all P values <.03). CONCLUSIONS AND CLINICAL IMPORTANCE: An association between MMVD and SM was not confirmed in this cohort of CKCS, indicating that MMVD and SM do not co-segregate. However, CKCS with symptomatic SM had smaller left ventricle and atrial size compared to CKCS with asymptomatic SM and CKCS without SM.

Dimensional and spatial computed tomographic abnormalities of the rectum and prostate are only partly reversible after surgical repair of perineal hernia in dogs.

Caudal protrusion of pelvic organs and dilatation and deviation of the rectum with perineal hernia (PH) have not previously been studied using CT, and it is not known how completely the changes normalize after PH repair. Objectives of this prospective experimental case series were to evaluate the dimensions and shape of the rectum and the volume, location, and other features (enhancement pattern, presence of cysts, and mineralizations) of the prostate of 66 dogs on CT before and 3 months after PH repair. The rectal cross-sectional areas were measured at intrapelvic and caudal locations, and the shape was categorized as straight, deviated, flexure, or caudal fold on dorsal images. According to paired samples t-tests, the caudal rectal dimensions were significantly larger (P < .001) than the intrapelvic dimensions both before and 3 months after PH repair, and according to linear mixed models, the intrapelvic dimensions increased significantly (P < .001) after repair. Before PH repair, the most common rectal shape was flexure (69.2%); after repair, the number of dogs having a straight rectum increased significantly (P < .001) according to the McNemar paired-samples proportion test. We were also able to show that rectal dimensions increased after PH repair despite straightening in most dogs. According to the linear mixed model, prostate ratio volume, and according to Wilcoxon signed ranks test, the number of prostates with intraprostatic cysts decreased significantly (both P < .001) after PH repair, but the proportion of prostates located in the caudal or perineal area did not. Small mineralizations remained in some dogs.

Enlargement of the hepatic artery is present in dogs with a congenital extrahepatic portosystemic shunt and is independent of shunt insertion into the systemic circulation.

The accurate diagnosis of portovascular anomalies has been facilitated by improvements in diagnostic imaging technology. In humans, hepatic arterial blood flow changes in response to the reduction in portal blood flow. The hepatic arterial buffer response characterizes an intrinsic regulatory mechanism in response to reduced portal venous blood flow, which results in hepatic arterial enlargement. At the authors' institution, enlargement of the hepatic artery has been anecdotally observed in a population of dogs with extrahepatic portosystemic shunting, consistent with previous literature that documents variability in hepatic arterial size. In this retrospective, blinded, analytical study, a hepatic artery:aorta (Ha:Ao) ratio was assessed on CT studies from 112 dogs, with (n = 43) and without (n = 69) an extrahepatic congenital portosystemic shunt in order to compare the hepatic artery size independent of body weight between the two populations. A significant increase in the Ha:Ao ratio was documented in dogs with an extrahepatic portosystemic shunt (EHPSS) compared with those dogs with no EHPSS independent of the location of shunt insertion into the systemic circulation (P < .001). Three cases had repeat CT after surgery, and all had Ha:Ao ratio reductions following treatment. The authors propose that this may be an additional imaging feature observed in dogs with an EHPSS.

CT features of cutaneous and subcutaneous canine mast cell tumors and utility of conventional and indirect lymphography to detect clinically unknown mast cell tumors and to map the sentinel lymph nodes.

Computed tomography is frequently used to stage canine mast cell tumors (MCTs). The aims of this prospective, observational study were to describe the CT features of MCTs, to evaluate the performance of CT in detecting additional or incidental MCTs, to distinguish between cutaneous (cMCT) or subcutaneous (scMCT) MCTs, and to identify one or multiple sentinel lymph nodes (SLNs) by indirect CT lymphography (ICTL). Seventy-two dogs affected by 111 MCTs were included. The recorded parameters were: shape, size, attenuation (Hounsfield units [HU]), location (cutaneous or subcutaneous), and presence of fat stranding. The SLNs were compared with the regional lymph nodes and supplementary MCTs were registered. Mast cell tumors mostly appeared with well-defined margins (89%), round/oval shape (71%), homogeneous enhancement (90%) with a mean postcontrast density of 62.0 ± 23.4 HU and associated with fat stranding (43%). Cutaneous mast cell tumors were more frequently round (P = .003), whereas scMCTs were oval (P = .011) with a larger mean maximal diameter (2.91 ± 1.57 cm vs 1.46 ± 1.28 cm, P = .002) and more feeding vessels (77% vs 39% P = .044). Compared with histopathology, CT accuracy in differentiating cMCTs and sMCTs was 57%, with an interobserver agreement of 88% (three reviewers). Indirect CT lymphography showed the SLN in 82 of 85 (97%) cases, 32% of them not corresponding to the regional node. CT showed additional or incidental MCTs in 23 of 72 (32%) dogs. In conclusion, the common CT appearance of canine cMCTs and scMCTs is reported with some statistical differences between the two categories. CT is useful in identifying clinically undetected MCTs and SLNs, although it shows low accuracy in distinguishing between cMCT and scMCT.