Ultrasonographic Evaluation of the Muscularis Propria in Cats with Diffuse Small Intestinal Lymphoma or Inflammatory Bowel Disease

Background: An ultrasonographic pattern of thickened muscularis propria in the small intestine and lymphadenopathy have been associated with gastrointestinal lymphoma and inflammatory bowel disease (IBD) in cats. Objectives: To investigate the association of these imaging biomarkers with IBD and lymphoma in cats. Animals: One hundred and forty‐two cats with a histologic diagnosis of normal small intestine (SI) (n = 56), lymphoma (n = 62), or IBD (n = 24). Methods: Retrospective case review. Pathology records from 1998–2006 were searched for cats with a diagnosis of normal, IBD, or lymphoma, an ultrasonographic examination <28 days before surgery, and without ultrasonographic evidence of a mass. Multinomial regression analysis was used to determine the association of imaging biomarkers with disease status. Results: Cats with thickening of the muscularis propria detected by ultrasonographic examination were more likely to have lymphoma compared with normal SI cats (odds ratio [OR] = 4.0, 95% confidence interval [95% CI] 1.2–13.1, P= .021) and those with IBD (OR = 18.8, 95% CI 2.2–162.7, P= .008). Histologic samples of cats with muscularis propria thickening were more likely to have disease infiltrates in both the mucosal and submucosal layers (OR = 8.1, 95% CI 1.7–38.4, P= .008) than cats with normal SI. Cats with ultrasonographic evidence of lymphadenopathy were more likely to have a diagnosis of lymphoma (OR = 44.9, 95% CI 5.1–393.0, P= .001) or IBD (OR = 10.8, 95% CI 1.1–106.3, P= .041) than normal SI. Fifty‐six of 62 cats had confirmed or presumptive diagnosis of diffuse T‐cell lymphoma. Conclusions and Clinical Relevance: Older cats with muscularis layer thickening are more likely to have T‐cell lymphoma than IBD. The ultrasonographic pattern is associated with histologic infiltrates in the mucosal and submucosal layers of small intestine. Lymphadenopathy is associated with lymphoma or IBD.     

Prognostic value of pretreatment plasma D‐dimer level in dogs with intermediate to high‐grade non‐Hodgkin lymphoma

Pretreatment D‐dimer levels have been reported to predict survival in several types of malignancies in human patients. The objective of this study was to evaluate the prognostic value of pretreatment D‐dimer level in dogs with intermediate to high‐grade non‐Hodgkin lymphoma (NHL). In a prospective, randomized, double‐blind study of F14512 vs etoposide phosphate, we assessed the prognostic value of pretreatment plasma D‐dimer level in 48 client‐owned dogs diagnosed with intermediate to high‐grade NHL. The correlation between pretreatment plasma D‐dimer level and various clinical features, progression‐free survival (PFS) and overall survival (OS) was analysed. The median value of pretreatment plasma D‐dimer level was 0.4 μg/mL (range: 0.1‐14.3 μg/mL). High pretreatment plasma D‐dimer level (>0.5 μg/mL) was detected in 44% (21/48) of dogs. High D‐dimer levels were not correlated with naive vs relapsed lymphoma, clinical stage, substage, immunophenotype or treatment group. D‐dimer levels >0.5 μg/mL were significantly associated with inferior median PFS (54 vs 104 days, P = .011) and OS (93 vs 169 days, P = .003). In the multivariate analysis, high D‐dimer levels remained an independent predictor for worse PFS (HR: 3.21, 95% CI: 1.57‐6.56, P = .001) and OS (HR: 3.87, 95% CI: 1.88‐7.98; P < .001). This study suggests that pretreatment plasma D‐dimer level can serve as a predictor of prognosis in dogs with intermediate to high‐grade NHL. Further studies are warranted to confirm these findings.     

Predictors of Clinical Remission in Cats with Diabetes Mellitus

Background: Clinical remission is frequent in cats with well‐controlled diabetes mellitus, but few studies explored predictors of this phenomenon. Hypothesis: Data retrieved from medical records at admission might be valuable to identify likelihood of remission and its duration in diabetic cats. Animals: Ninety cats with newly diagnosed diabetes, followed‐up until death or remission. Methods: Retrospective cohort study. Data were collected from records at admission, including history, signalment, physical examination, haematology, and biochemical profile, and the occurrence and duration of remission, defined as normoglycemia without insulin for ≥4 weeks. Predictors of remission were studied with univariate and multivariate logistic regression. Factors associated with remission duration were analyzed with Kaplan‐Meier and Cox proportional hazard models. Results: Forty‐five (50%) cats achieved remission, after a median time of 48 days (range: 8–216). By study end, median remission duration was 114 days (range: 30–3,370) in cats that died and 151 days (range: 28–1,180) in alive cats. Remission was more likely with higher age (OR: 1.23, 95% CI: 1.04–1.46; P= .01) and less likely with increased serum cholesterol (OR: 0.36, 95% CI: 0.11–0.87; P= .04). Remission was longer with higher body weight (HR: 0.65, 95% CI: 0.42–0.99; P= .04) and shorter with higher blood glucose (HR: 1.01, 95% CI: 1.00–1.02; P= .02). Conclusions and Clinical Importance: Age, body weight, cholesterol, and glucose levels are suggested for prediction of remission or its duration in diabetic cats. Older cats developing diabetes may have a better outcome, possibly suggesting a slower disease progression.     

Outcome of stereotactic body radiation for treatment of nasal and nasopharyngeal lymphoma in 32 cats

BackgroundThe safety and efficacy of stereotactic body radiation therapy (SBRT) in the treatment of localized nasal lymphoma in cats has not been described.HypothesisStereotactic body radiation therapy with or without adjuvant chemotherapy is an effective and well‐tolerated treatment for localized nasal lymphoma in cats.AnimalsThirty‐two client owned cats referred to Colorado State University for the treatment of nasal lymphoma.MethodsRetrospective study of cats treated with SBRT between 2010 and 2020 at Colorado State University. Diagnosis of nasal lymphoma was obtained via cytology or histopathology. Signalment, radiation protocol, concurrent treatments, adverse effects, and survival were recorded.ResultsProgression free survival was 225 days (95% CI 98–514) and median survival time (MST) was 365 days (95% CI 123–531). No significant difference in survival was identified between cats that received 1 versus greater than 1 fraction (MST 427 vs. 123 days, P = 0.88). Negative prognostic factors included cribriform lysis (MST 121 vs. 876 days, P = 0.0009) and intracalvarial involvement (MST 100 vs. 438 days, P = 0.0007). Disease progression was noted in 38% (12/32), locally in 22% (7/32), and systemically in 16% (5/32). No cats developed acute adverse effects. Ten cats developed late adverse effects: keratitis/keratitis sicca (n = 2), alopecia (n = 4), and leukotrichia (n = 4). Twenty‐four cats (75%) had signs consistent with chronic rhinitis.ConclusionsSBRT is effective and well tolerated for treating localized nasal lymphoma in cats. Outcomes for cats with lower stage disease (canine modified Adam''s stage 3 and lower) are comparable to historic data of cats treated with fractionated radiation therapy.     

Hematology and Serum Biochemistry of Feline Immunodeficiency Virus-Infected and Feline Leukemia Virus-Infected Cats

Background: Hematological and biochemical values in cats naturally infected by feline immunodeficiency virus (FIV) or feline leukemia virus (FeLV) are not completely documented. Objective: Report differences in laboratory values between FIV‐ or FeLV‐infected and noninfected and between FIV‐ and FeLV‐infected cats. Animals: Three thousand seven hundred and eighty client‐owned cats tested for FIV and FeLV. Methods: Retrospective study. Evaluation of clinicopathologic changes in cats with defined FIV and FeLV status and for which laboratory data were available. Results: FIV‐infected cats were more likely to be neutropenic (odds ratio [OR]=3.6, 95% confidence interval [95% CI] 2.1–6.2, P < .0001) and had lower serum activities of aspartate aminotransferase and glutamate dehydrogenase than control cats; serum total protein (8.1 ± 1.1 versus 7.6 ± 1.3 g/dL, P < .001) and γ‐globulin concentrations (2.2 ± 1.1 versus 1.7 ± 1.3 g/dL, P < .001) were higher than in uninfected cats. Compared with controls, FeLV‐infected cats had a higher risk of anemia (OR = 3.8, 95% CI 2.4–6.0, P < .0001), thrombocytopenia (OR = 5.0, 95% CI 3.0–8.4, P < .0001), neutropenia (OR = 3.6, 95% CI 2.1–6.1, P < .0001), lymphocytosis (OR = 2.8, 95% CI 1.6–4.8, P= .0002), and lower erythrocyte counts (6.13 ± 2.95 × 10³ versus 8.72 ± 2.18 × 10³/μL, P < .001), thrombocyte counts (253.591 ± 171.841 × 10³ versus 333.506 ± 156.033 × 10³/μL, P < .001), hematocrit (28.72 ± 12.86 versus 37.67 ± 8.90%, P < .001), hemoglobin and creatinine concentration. Conclusions and Clinical Importance: Hematologic abnormalities are common in FeLV‐infected but not in FIV‐infected cats. Clinicopathologic abnormalities are less frequent in FIV‐infected cats and might reflect an unspecific immunologic response.     

Toxicity and outcome in cats with oral squamous cell carcinoma after accelerated hypofractionated radiotherapy and concurrent systemic treatment

Recently, a multimodal approach to oral squamous cell carcinoma (SCC) in cats, combining medical treatment and accelerated radiation therapy, showed a substantial outcome improvement in a small pilot study. Herein we retrospectively review 51 cats with unresectable, histologically confirmed oral SCC and a complete initial staging work‐up: cats in group A (n = 24) received medical anti‐angiogenic treatment consisting of bleomycin, piroxicam and thalidomide, cats in group B (n = 27) received the anti‐angiogenic treatment and concurrent accelerated hypofractionated radiation therapy with 48Gy delivered in 10 fractions. Overall median progression‐free interval (PFI) was poor with 70 days (95% CI: 48;93). In the irradiated cats (group B), however, PFI was significantly longer with 179 days (95% CI: 58;301) days, vs 30 days (95% CI: 23;38) in medically only treated cats (P < .001). Overall median overall survival (OS) was 89 days (95% CI: 55;124), again significantly longer in the irradiated cats (group B) with 136 (95% CI: 40;233) vs 38 days (95% CI: 23;54) (P < .001). In 8 of the 27 (29.6%) cats in group B, however, severe toxicity (grade 3) occurred. Neither onset nor severity of toxicity could be associated with any of the tested variables, including anatomic site, tumour size, clinical stage and duration of neoadjuvant medical treatment. Given the potential severe acute effects and the impact on quality of life after chemo‐radiotherapy, owners must be clearly informed about the risks of treatment. With the overall poor outcome and high occurrence of acute toxicity, we cannot recommend the use of this accelerated radiation protocol combined with anti‐angiogenic therapy for oral SCC in cats.     

Prognostic significance of clinical presentation,induction and rescue treatment in 42 cases of canine centroblastic diffuse large B‐cell multicentric lymphoma in the United Kingdom

Canine lymphoma is a heterogeneous group of diseases and many previous studies have evaluated the response of a mixed population of lymphoma cases to one specific treatment protocol. The aim of this retrospective study was to describe the outcome and prognostic factors in 42 cases of multicentric centroblastic diffuse large B‐cell lymphoma treated with either a COP‐type (35%) or CHOP‐type (64%) induction chemotherapy. The objective response rate to induction therapy was 94%; entire dogs had a greater rate of complete vs partial remissions than neutered dogs (P = .017). Median progression‐free survival for the first remission (PFS1) was 182 days; absence of anaemia at diagnosis (P = .002) and pretreatment neutrophil:lymphocyte ratio (NLR) below 9.44 (P = .015) were independently predictive of longer PFS1. Fifty‐eight percent of dogs received rescue protocols with an objective response rate of 81%; 31% of dogs received further rescue protocols (up to a total of 5) and the median number of protocols administered were 2. Median overall survival (OS) was 322 days, the 1‐year survival rate was 38% and the 2‐year survival rate was 9%. Lymphocyte:monocyte ratio above 1.43 (P = .031), NLR below 11.44 (P = .009), the combination of induction and rescue therapy (P = .030) and the total number of doxorubicin doses used (P = .002) were independently predictive of longer OS. Use of a COP‐type protocol induction compared with CHOP did not undermine OS providing doxorubicin was used as rescue therapy.     

Retrospective analysis of factors affecting clinical outcome following CHOP‐based chemotherapy in dogs with primary nodal diffuse large B‐cell lymphoma

Numerous factors are known to affect the prognosis of dogs with chemotherapy‐treated lymphomas. However, prognostic factors for dogs with specific subtypes of lymphoma are less clearly defined. The objective of this study was to identify prognostic factors for dogs receiving CHOP‐based chemotherapy for primary nodal diffuse large B‐cell lymphoma (DLBCL). Medical records of dogs treated for DLBCL at the Purdue Veterinary Teaching Hospital (PUVTH) from 2006 to 2016 were reviewed. Factors potentially related to prognosis were analysed using multivariable statistical methods. Ninety‐eight dogs were included in the study. Best overall response to chemotherapy was complete remission in 80 dogs (81.6%) and partial remission in 18 dogs (18.4%). Median progression‐free survival (PFS) for the entire population was 252 days (range 19‐1068). Factors significantly associated with achieving partial (rather than complete) remission following CHOP included presence of thrombocytopenia at diagnosis (OR 6.88; 95% CI 1.98‐23.93; P = .002), baseline serum globulin concentration (OR 2.63; 95% CI 1.03‐6.75; P = .044), and age at diagnosis (OR 1.36; 95% CI 1.08‐1.71; P = .009). Factors significantly associated with PFS in the lowest quartile (≤93 days) included presence of thrombocytopenia at diagnosis (OR 8.72; 95% CI 1.54‐49.33; P = .014), age at diagnosis (OR 1.47; 95% CI 1.12‐1.94; P = .005), and baseline neutrophil count (OR 1.18; 95% CI 1.02‐1.37; P = .025). Presence of thrombocytopenia, greater age, higher neutrophil count, and higher serum globulin concentration all may be associated with a particularly poor outcome in dogs receiving CHOP‐based chemotherapy for DLBCL.     

Combination vinblastine and palladia for high-grade and metastatic mast cell tumors in dogs

High-grade and metastatic canine mast cell tumors carry a guarded prognosis because of their unpredictable biologic behavior. An ideal chemotherapy regime is yet to be established. The aim of this study was to review the efficacy and toxicity of combination vinblastine and toceranib for high-grade and metastatic mast cell tumors. Twenty-eight dogs were categorized with either high-grade, lymph node metastasis or Stage IV disease. Demographics, disease, and treatment variables were compared between categories (Kruskal-Wallis test for continuous data and Fisher’s Exact test for categorical data). Survival times and progression-free intervals (PFI) were calculated and compared between groups (log rank test). The PFI was 310 d [95% confidence interval (CI): 155 to 1425] and overall survival was 373 d (95% CI: 226 to 1219). There was no difference between disease categories for PFI (P = 0.9) or survival (P = 0.5). The protocol was well-tolerated with increased liver enzyme activity and gastrointestinal toxicity most frequently observed. Progression-free intervals and survival times were similar in dogs with high-grade, metastatic and Stage IV disease.     

Risk factors for neonatal calf diarrhoea and enteropathogen shedding in New Zealand dairy farms

To investigate the risk factors for neonatal calf diarrhoea, a cross-sectional study was conducted on 97 New Zealand dairy farms. Faecal specimens from 1283 calves were scored as liquid, semi-solid or solid, and analysed for bovine rotavirus (BRV) and coronavirus (BCV), enterotoxigenic K99⁺ Escherichia coli (K99), Salmonella spp. and Cryptosporidium parvum. Calf- and farm-level data were collected by means of a questionnaire and the odds of liquid faeces calculated using mixed effects logistic regression models.Among the infectious agents, only C. parvum (odds ratio [OR] = 2.6; 95% confidence interval [CI], 1.3–5.6; P = 0.02), BRV (OR = 2.7; 95% CI, 1.3–5.9; P = 0.01) and co-infection with more than one agent (compared with mono-infection: OR = 2.5; 95% CI, 1.3–4.8; P = 0.01) were associated with increased odds of liquid faeces in calves which were 9 to 21 days old. Housing of calves in open barns so exposing them to the weather was also associated with increased odds of liquid faeces compared with closed barns (OR = 2.1; 95% CI, 1.1–12.2; P = 0.03). Vaccinating cows against calf enteropathogens (OR = 0.2; 95% CI, 0.1–0.9; P = 0.03), administering waste milk (from mastitis and/or containing antibiotics; OR = 0.4; 95% CI, 0.1–0.8; P = 0.01), the sex of calves (females compared to males OR = 0.2, 95% CI, 0.07–0.7; P <0.01), and the use of straw for bedding (OR = 0.2; 95% CI, 0.03–0.9; P = 0.03) decreased the odds of liquid faeces. Conversely, in calves that were 1 to 5 days old, only K99 was associated with liquid faeces (OR = 4.6; 95% CI, 1.2–16.1; P = 0.02). In this age group, the odds of liquid faeces were smaller on farms where females took care of the calves, compared with males (OR = 0.4; 95% CI, 0.01–0.9; P = 0.04).     

Environmental risk factors for the development of oral squamous cell carcinoma in cats

BackgroundRisk factors for oral squamous cell carcinoma (OSCC) in cats are derived from a single study dated almost 20 years ago. The relationship between inflammation of oral tissues and OSCC is still unclear.ObjectivesTo investigate previously proposed and novel potential risk factors for OSCC development, including oral inflammatory diseases.AnimalsHundred cats with OSCC, 70 cats with chronic gingivostomatitis (CGS), 63 cats with periodontal disease (PD), and 500 controls.MethodsProspective, observational case‐control study. Cats with OSCC were compared with an age‐matched control sample of client‐owned cats and cats with CGS or PD. Owners of cats completed an anonymous questionnaire including demographic, environmental and lifestyle information.ResultsOn multivariable logistic regression, covariates significantly associated with an increased risk of OSCC were rural environment (OR: 1.77; 95% CI: 1.03‐3.04; P = .04), outdoor access (OR: 1.68; 95% CI: 1.07‐2.63; P = .02), environmental tobacco smoke (OR: 1.77; 95% CI: 1.05‐3; P = .03), and petfood containing chemical additives (OR: 1.98; 95% CI: 1.04‐3.76; P = .04). Risk factors shared with CGS and PD were outdoor access and petfood containing chemical additives, respectively. A history of oral inflammation was reported in 35% of cats with OSCC but did not emerge as a risk factor.Conclusions and Clinical ImportanceThe study proposes novel potential risk factors for OSCC in cats. Although a history of inflammatory oral disease was not significantly more frequent compared with random age‐matched controls, OSCC shared several risk factors with CGS and PD.     

Prognostic significance of hypermethylation of death‐associated protein kinase (DAPK) gene CpG island in dogs with high‐grade B‐cell lymphoma

Death‐associated protein kinase (DAPK) is a serine/threonine kinase and a tumour suppressor gene. Diffuse large B‐cell lymphomas with inactivated DAPK through hypermethylation of a CpG island is known to result in a biologically aggressive phenotype in humans. This retrospective study was carried out to analyse the prognostic significance of DAPK CpG island hypermethylation in canine lymphoma. We hypothesized that DAPK CpG island hypermethylation can be a negative prognostic indicator in dogs with nodal high‐grade B‐cell lymphoma. Forty‐seven dogs with high‐grade B‐cell lymphoma, according to the updated Kiel classification, were evaluated after being treated with a CHOP (vincristine, cyclophosphamide, doxorubicin and prednisolone)‐based chemotherapy protocol. The methylation status of the DAPK CpG island was examined by methylation‐specific PCR. Progression‐free survival (PFS) and overall survival (OS) were compared using the Kaplan‐Meier analysis and log‐rank test. The cox proportional hazard regression model was used to evaluate the effect of multiple variables. Hypermethylation of the DAPK CpG island was detected in 21 of the 47 dogs. The PFS and OS in dogs with the hypermethylation (median: 220 and 266 days, respectively) were significantly shorter than those of dogs without hypermethylation (median: 301 and 412 days, respectively) (PFS, P = .036; OS, P = .007). In the multivariate analysis, hypermethylation of the DAPK CpG island remained an independent prognostic factor in predicting shortened PFS (P = .047) and OS (P = .021) as well as clinical substage b. Overall, hypermethylation of the DAPK CpG island was a negative prognostic factor in canine high‐grade B‐cell lymphoma.     

Pretreatment leukocyte ratios and concentrations as predictors of outcome in dogs with cutaneous mast cell tumours

Leukocyte ratios correlate with outcome in several human cancers. Little is known about their prognostic significance in mast cell tumour (MCT). The aim of the study was to evaluate the prognostic significance of pretreatment leukocyte concentrations and their ratios in dogs with MCT for survival. Medical records of 92 dogs with MCT were retrospectively reviewed. Tumour diagnosis was made by tumour biopsy or fine‐needle aspirate. Only dogs without prior treatment were included. Eosinophil, lymphocyte, monocyte and neutrophil concentration were obtained by ADVIA 2120? (Siemens Healthcare, Vienna, Austria). Neutrophil‐to‐eosinophil ratio (NER), lymphocyte‐to‐monocyte ratio (LMR) and neutrophil‐to‐lymphocyte ratio (NLR) were calculated from collected leukocyte concentrations. Relative eosinophil concentration (REC), NER (P < 0.001), NLR (P = 0.001) and LMR (P < 0.001) were significant prognostic factors for outcome in univariate analysis. REC (P = 0.008) and NER (P = 0.001) remained independent predictors of survival in multiple analyses. Leukocyte concentrations and ratios, especially REC and NER may serve as prognostic indicators in MCT.     

Treatment of intracranial neoplasia in dogs using higher doses: A randomized controlled trial comparing a boosted to a conventional radiation protocol

BackgroundLocal progression of intracranial tumors can be the consequence of insufficient radiation dose delivered. Dose increases in the brain must be made carefully so as not to risk debilitating adverse effects such as radiation necrosis.HypothesisA new protocol with 10 × 4 Gy + 11% physical dose increase limited to the macroscopic tumor volume results in a clinically better outcome compared to a 10 × 4 Gy protocol.AnimalsFifty‐seven client‐owned dogs with primary intracranial neoplasia.MethodsRandomized controlled trial. Twenty‐eight dogs were assigned to the control protocol (10 × 4 Gy) and 29 to the simultaneous integrated boost (SIB) protocol with 4.45 Gy dose increase. Treatment groups were compared for outcome and signs of toxicity.ResultsMild, transient acute or early‐delayed adverse radiation effects were observed in 5 dogs. Severe late adverse effects were not seen. Between the protocols, no significant differences were found for outcome (intention‐to‐treat analysis): overall time to progression (TTP) was 708 days (95% confidence interval (95% CI) [545,872]), in the control group it was 828 days (95% CI [401,1256]), and in the SIB group 627 days (95% CI [282,973]; P = .07). Median overall survival (OS) was 684 days (95% CI [516,853]), in the control group it was 724 days (95% CI [623,826]), and in the SIB group 557 days (95% CI [95,1020]; P = .47). None of the tested variables was prognostic in terms of outcome.Conclusion and Clinical ImportanceThe dose escalation used with an 11% physical dose increase did not result in better outcome.     

Retrospective analysis of outcome and prognostic factors of subcutaneous mast cell tumours in dogs undergoing surgery with or without adjuvant treatment

Subcutaneous mast cell tumours (SC MCTs) can display a different biological behaviour in dogs when compared to their cutaneous counterpart. There is a paucity of information with regards to the outcome of dogs with SC MCTs treated with surgery and/or receiving adjuvant chemotherapy. The aim of this study was to retrospectively review the outcome of dogs with surgically excised SC MCTs undergoing adjuvant treatment or not. A secondary aim was to assess prognostic factors in the same group. Fifty-two cases were included. Recurrence rate was 15% and 63% of evaluated lymph nodes were consistent with early or overt metastasis. Median survival time (range 83–1357 days) and median time to progression (range 14–1357 days) were not reached. Factors predictive of shorter overall survival time included increasing age (HR 1.29, 95% CI 1.06–1.55, p = .0092), presence of clinical signs at presentation (HR 10.44, 95% CI 2.69–40.52, p = .0007), mitotic count >4 (HR 8.69, 95% CI 2.55–29.55, p = 0.0005), presence of multinucleation (HR 4.21, 95% CI 1.35–13.18, p = .0135), use of neoadjuvant and adjuvant chemotherapy (HR 7.16, 95% CI 1.26–40.73, p = .0266). The same factors, together with increasing tumour dimensions, were predictive for shorter progression-free survival (PFS), including increasing age (p = .0012), presence of clinical signs at presentation (p = .0045), increasing tumour dimensions (p = .0004), MC > 4 (p = .0004), presence of multinucleation (p = .0282), use of neoadjuvant and adjuvant chemotherapy (p = .0485). No variables remained significant for overall survival using multivariate analysis. There was a longer survival in cases where chemotherapy was not required (HR 0.14, 95% CI 0.03–0.68, p = .0148), and this variable remained significant for PFS on multivariate analysis (HR 0.13, 95% CI 0.02–0.76, p = .02). In conclusion, our study suggests that dogs with SC MCTs, in the absence of negative prognostic factors, may have a prolonged survival when treated with surgery alone. Further studies are needed to clarify the role of adjuvant treatment for biologically aggressive SC MCTs in dogs.     

Transvenous electrical cardioversion of atrial fibrillation in horses: Horse and procedural factors correlated with success and recurrence

BackgroundTransvenous electrical cardioversion (TVEC) is 1 of the main treatment options for atrial fibrillation (AF) in horses. Large‐scale studies on factors affecting success and prognosis have primarily been performed in Standardbred populations.Hypothesis/ObjectivesTo determine factors affecting cardioversion success, cardioversion difficulty and recurrence in a predominant Warmblood study sample.AnimalsTVEC records of 199 horses.MethodsRetrospective study of TVEC procedures of horses admitted for AF without severe echocardiographic abnormalities. Horse and procedural factors for success and cumulative amount of energy (≤ 600 J vs > 600 J) were determined using multivariable logistic regression. A survival analysis was performed to determine risk factors for recurrence.ResultsTwo hundred and thirty‐one TVEC procedures were included, with a 94.4% success rate and 31.9% recurrence rate (51/160). Mitral regurgitation (OR 0.151, 95% CI 0.032‐0.715, P = .02) and AF cycle length (OR 1.05, 95% CI 1.01‐1.09, P = .02) were independent determinants for success. Catheter type (OR 0.154, 95% CI 0.074‐0.322, P < .001), previous AF episode (OR 3.10, 95% CI 1.20‐8.01, P = .02), tricuspid regurgitation (OR 2.54, 95% CI 1.25‐5.13, P = .01), and body weight (OR 1.009, 95% CI 1.003‐1.015, P = .004) were significantly correlated with cumulative amount of energy delivered. Significant risk factors for recurrence after a first AF episode were sex (stallion; HR 3.05, 95% CI 1.34‐6.95, P = .008), mitral regurgitation (HR 1.91, 95% CI 1.08‐3.38, P = .03), and AF duration (HR 1.001, 95% CI 1.0001‐1.0026, P = .04).Conclusions and Clinical ImportanceBoth horse and procedural factors should be considered when assessing treatment options and prognosis in horses with AF.     

Serum thymidine kinase 1 activity as a prognostic biomarker in dogs with chemotherapy-treated diffuse large B-cell lymphoma

Diffuse large B-cell lymphoma (DLBCL) is frequently treated with chemotherapy incorporating cyclophosphamide, doxorubicin, vincristine and prednisone (CHOP), which induces remission in 80% to 95% of cases. However, not all dogs derive meaningful benefit from CHOP, and prognostic factors for dogs with DLBCL are poorly defined. Serum thymidine kinase 1 (TK1) activity, a marker of tumour cell proliferation, has shown promising initial results as a prognostic biomarker in dogs with multicentric lymphomas. The purpose of this study was to determine if baseline serum TK1 activity is associated with clinical outcome in dogs with CHOP-treated DLBCL. Baseline serum TK1 activity was measured in banked sera from 98 dogs with CHOP-treated DLBCL using a commercially available ELISA kit. Data on other potential prognostic factors were abstracted retrospectively from electronic medical records. Multivariable statistical methods were used to identify associations between TK1 and other potential prognostic factors with progression-free survival (PFS) and attainment of complete remission. TK1 activity at baseline was not associated with PFS (p = .299) or attainment of complete remission (p = .910) following CHOP chemotherapy. Of the other prognostic factors analysed, only purebred (vs. mixed breed) status (HR 8.81, 95% CI 1.68–46.30, p = .010), attainment of complete (vs. partial) remission (HR 0.09, 95% CI 0.02–0.49, p = .006), and baseline serum C-reactive protein concentration (HR 1.19, 95% CI 1.07–1.32, p = .001) were independently associated with PFS. Based on these findings, baseline serum TK1 activity does not appear to be a useful prognostic biomarker in dogs with CHOP-treated DLBCL.