A 3-year-old Pygmy Wether was presented for chronic hindlimb paralysis. A neurological exam revealed nonambulatory paraplegia with absent deep pain nociception, lack of hindlimb withdrawal reflexes, and paraspinal pain on palpation with T3 to L3 neurolocalization. MRI of the lumbar spine revealed an extensive, dorsal to dorsolateral, severely compressive, heterogeneously contrast-enhancing extradural lesion of the lumbar spine with intervertebral foraminal extension into the surrounding paraspinal musculature. Vertebral bone marrow involvement was also noted in the L5 and L6 vertebrae. A diagnosis of lymphoma was obtained after cytological sampling. This is the first case report describing specific MRI findings (signal characteristics, enhancement pattern, and perilesional changes) in a goat with paraspinal lymphoma.

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±1.57cm vs 1.46±1.28cm, 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.

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.

Stereotactic body radiation therapy (SBRT) is an increasingly used alternative treatment option for nonresectable hepatocellular carcinoma (HCC) in people. Comparatively, the publication of SBRT of dogs with HCC is limited. The objective of this retrospective, descriptive case series was to evaluate the clinical outcomes and toxicity data of SBRT in dogs with HCC and imaging-documented primary liver tumors using volumetric-modulated arc therapy delivery at two private institutions. Medical records of 14 dogs treated between 2018 and 2023 were reviewed. All dogs had macroscopic tumors, and 9 of 14 dogs had HCC diagnoses confirmed on cytology or histopathology. The median longest tumor diameter was 5.5cm. The median percentage of planning target volume relative to liver volume was 27.1%. Most dogs were treated with three daily fractions of 7-7.5Gy. All dogs completed their radiotherapy protocols. Three of nine HCC dogs experienced partial responses and clinical improvement. Five of nine HCC dogs had stable disease. Overall median survival time was 164 days for nine HCC dogs (range: 93-706 days). One late grade 5 liver and two late grade 3 kidney side effects were reported. One dog received repeated SBRT to the same HCC treatment field, and one dog had two courses of SBRT to bifocal HCC treatment fields, both with no more than grade 2 acute and chronic toxicities.