Ultrasonographic liver nodules are more often benign lesions in dogs with hemoperitoneum secondary to splenic tumor rupture.

OBJECTIVE: To evaluate the reliability of preoperative abdominal ultrasonography as a staging tool for dogs with hemoperitoneum due to presumed splenic tumor rupture, focusing on the detection of metastatic lesions in the liver. ANIMALS: 99 dogs from 20 emergency and specialty hospitals across the US. METHODS: Dogs with nontraumatic hemoperitoneum secondary to splenic tumor rupture were included. A post hoc analysis was conducted on data from a nationwide prospective trial investigating novel treatments for canine hemangiosarcoma. The accuracy of preoperative staging was assessed by comparing ultrasonographic findings with intraoperative observations and histologic findings. RESULTS: On preoperative ultrasonography, there was a 20% incidence of liver lesions identified, with no association to liver lesions seen during operation. Notably, 22% of liver lesions observed during operation were missed on preoperative ultrasonography. The presence of liver lesions on preoperative ultrasonography was associated with a higher likelihood of a benign splenic tumor diagnosis. There was no association between the identification of liver lesions on preoperative ultrasonography and the presence of metastatic disease on liver biopsy, with a sensitivity and specificity of 19% and 82%, respectively. Additionally, ultrasound had low sensitivity in detecting intra-abdominal lesions beyond the liver and spleen, with 82% of these lesions missed preoperatively. CLINICAL RELEVANCE: This study challenges conventional perceptions around the approach to staging in dogs with hemoperitoneum. These findings advocate for a reevaluation of the staging approach, with more comprehensive modalities like whole-body CT or MRI potentially being more warranted.

Associations of abdominal discomfort and length of clinical signs with surgical procedure in 181 cases of canine small intestinal foreign body obstruction.

BACKGROUND: Gastrointestinal foreign bodies are a common indication for abdominal exploratory surgery. OBJECTIVES: The objective of this study was to evaluate the relationship of pre-operative abdominal discomfort and duration of clinical signs with surgical resolution of canine small intestinal foreign body obstructions (SIFBO). METHODS: We performed a retrospective study of 181 canine abdominal exploratory surgeries for confirmed SIFBO at two referral hospitals. Animals were categorized into five surgical groups (gastrotomy after manipulation into the stomach, enterotomy, resection-and-anastomosis [R&A], manipulated into colon, already in colon) and further grouped by whether entry into the gastrointestinal tract (GIT) was required. RESULTS: Abdominal discomfort was noted in 107/181 cases (59.1%), but no significant differences in abdominal discomfort rates were present among the surgical groups or between GIT entry and no entry groups. Clinical sign duration was associated with surgical procedure; median durations were R&A = 3 days (range, 1-9), enterotomy = 2 days (range, 1-14), gastrotomy = 2 days (range, 1-6), already in colon = 1.5 days (range, 1-2), and manipulated into colon = 1 day (range, 1-7). In a pairwise comparison, differences in the duration of clinical signs were found for obstructions manipulated into the colon versus R&A, gastrotomy versus R&A, and in colon versus R&A. When patients were grouped according to GIT entry, cases with entry had a longer duration of clinical signs (median = 2 days [range, 1-14] versus 1 day [range, 1-7], respectively). CONCLUSIONS: Abdominal discomfort was not associated with surgical complexity; however, the duration of clinical signs was associated with surgical complexity, with longer duration being associated with entry into the GIT and R&A. Despite statistical significance, the maximum difference of 2 days between surgical groups is unlikely to be clinically relevant.

Pharmacokinetic Exposures Associated With Oral Administration of Sorafenib in Dogs With Spontaneous Tumors.

Sorafenib is a multi-kinase small molecule inhibitor that targets serine/threonine and tyrosine kinases including the RAF kinase family, VEGFR-2, and PDGFR. The aim of this study was to evaluate the systemic pharmacokinetics of a previously defined tolerable oral dose of sorafenib in tumor-bearing dogs. Six client-owned dogs with a cytologic or histologic diagnosis of cancer were enrolled in this open-label, tolerability study. Dogs were administered sorafenib at an intended dose of 3 mg/kg and serum samples were obtained for analysis of sorafenib serum concentrations at 0, 1, 2, 6, 12, 24, 48, 72, 96, and 168 h post-drug administration. Median time to peak serum sorafenib concentration occurred at 4 h (range 2-12 h) resulting in an average serum concentration of 54.9 ± 33.5 ng/mL (118.2 ± 72.1 nM). Mean sorafenib levels declined by over 70% relative to peak serum concentrations by 24 h in all dogs, suggesting the value of at least twice daily administration. Doses of 3 mg/kg were well-tolerated and no patients in the study experienced adverse events that were attributable to sorafenib. Future trials in dogs with cancer are recommended at this dosing schedule to assess the effect of sorafenib administration on anti-tumor efficacy signals and relevant pharmacodynamic target modulation in vivo.

Prevalence and clinical features of thoracolumbar intervertebral disc-associated epidural hemorrhage in dogs.

BACKGROUND: Intervertebral disc-associated epidural hemorrhage (EH) in dogs is a poorly understood neurological condition. OBJECTIVE: To compare the clinical presentation, magnetic resonance imaging (MRI) changes, and clinical outcome of dogs with acute thoracolumbar intervertebral disc herniation (TL-IVDH) with and without EH. ANIMALS: One hundred sixty client-owned dogs that underwent MRI and hemilaminectomy for acute TL-IVDH at a private practice in Colorado, including 63 dogs with EH and 97 dogs without EH. METHODS: Retrospective review of medical record data from 160 dogs presenting sequentially to a single practice with acute TL-IVDH that underwent MRI and hemilaminectomy surgery. RESULTS: Sixty-three of 160 (39%) dogs had confirmed EH. French Bulldogs were significantly overrepresented (23/63; odds ratio [OR]: 4.1; 95% confidence interval [CI]: 1.8-9.0; P < .001) of the EH cases. Dogs with EH were more likely to present with clinical signs less than 48 hours than were dogs without EH (24-48 vs 48-72 hours; OR: 2.4; 95% CI: 1.2-4.6; P = .02) and were more likely to be nonambulatory on presentation (OR: 2.1; 95% CI: 1.0-4.1; P = .04). Dogs with EH were more likely to have <50% cross-sectional spinal cord compression than dogs without EH (OR: 2.3 vs. 0.4; 95% CI: 1.2-4.4 and 0.2-0.9, respectively), longer longitudinal spinal cord compression (3 spaces vs 1 space, P < .001), and greater intrinsic spinal cord change (grade 3/severe vs grade 1/mild; P < .001) based on MRI. The location of the intervertebral disc herniation in French Bulldogs with EH was more likely to be thoracolumbar (OR: 10.8; 95% CI: 2.1-55.7; P = .03). CONCLUSIONS AND CLINICAL IMPORTANCE: French Bulldogs have a high prevalence of intervertebral disc-associated EH. Dogs with EH have a shorter clinical course and are more likely to be nonambulatory on initial presentation.

Feasibility of circulating tumor DNA analysis in dogs with naturally occurring malignant and benign splenic lesions.

Comparative studies of naturally occurring canine cancers have provided new insight into many areas of cancer research. Development and validation of circulating tumor DNA (ctDNA) analysis in pet dogs can help address diagnostic needs in veterinary as well as human oncology. Dogs have high incidence of naturally occurring spontaneous cancers, demonstrate molecular heterogeneity and clonal evolution during therapy, allow serial sampling of blood from the same individuals during the course of disease progression, and have relatively compressed intervals for disease progression amenable to longitudinal studies. Here, we present a feasibility study of ctDNA analysis performed in 48 dogs including healthy dogs and dogs with either benign splenic lesions or malignant splenic tumors (hemangiosarcoma) using shallow whole genome sequencing (sWGS) of cell-free DNA. To enable detection and quantification of ctDNA using sWGS, we adapted two informatic approaches and compared their performance for the canine genome. At the time of initial clinical presentation, mean ctDNA fraction in dogs with malignant splenic tumors was 11.2%, significantly higher than dogs with benign lesions (3.2%; p = 0.001). ctDNA fraction was 14.3% and 9.0% in dogs with metastatic and localized disease, respectively (p = 0.227). In dogs treated with surgical resection of malignant tumors, mean ctDNA fraction decreased from 11.0% prior to resection to 7.9% post-resection (p = 0.047 for comparison of paired samples). Our results demonstrate that ctDNA analysis is feasible in dogs with hemangiosarcoma using a cost-effective approach such as sWGS. Additional studies are needed to validate these findings, and determine the role of ctDNA to assess burden of disease and treatment response in dogs with cancer.

Prospective observational study of dogs with splenic mass rupture suggests potentially lower risk of malignancy and more favourable perioperative outcomes.

Haemoperitoneum secondary to ruptured splenic tumours can be either benign or malignant in origin. The majority of previous studies of canine haemoperitoneum have been retrospective, which are associated with well-recognized biases, such as the potential to underappreciate the diversity of outcomes in a complex presentation such as haemoperitoneum. This study seeks to prospectively define perioperative morbidity and mortality of haemoperitoneum in dogs secondary to ruptured splenic masses. Forty dogs with haemoperitoneum secondary to a ruptured splenic mass met the inclusion criteria. As expected, the cohort predominately consisted of older large breed dogs. All dogs underwent preoperative staging and had a splenectomy performed. Histopathologic analysis was performed on the splenic mass, as well as any possible metastatic lesions that were noted intra-operatively. Perioperative care outside of splenectomy was delivered in specialty practices using current conventional approaches to care (eg, transfusions and anti-arrhythmic medications). Fifteen dogs (37.5%) had benign splenic tumours and were cured with surgery alone, whereas 62.5% had malignant disease (most often haemangiosarcoma [HSA]). Surgical outcomes were highly favourable in the vast majority of dogs. Indeed, 38 dogs (95%) survived and were discharged after a median hospitalization of 39.5 hours. Independent predictors of longer hospitalization times included receiving a transfusion and the development of an arrhythmia. Although small, this cohort defines distinctive and optimistic perspectives for dogs with haemoperitoneum from splenic tumour rupture. These favourable outcomes from this prospective study are sufficient to ask if larger prospective studies should be conducted to better inform owners during this challenging cancer emergency presentation.