Cell-free DNA (cfDNA) is derived from apoptosis/necrosis, active cellular secretion, and lysis of circulating cancer cells or micrometastases. In humans, cfDNA is widely used in cancer diagnosis, but veterinary research has yet to be actively conducted to establish it as a cancer biomarker. This retrospective study analyzed cfDNA levels in samples collected from dogs with neoplastic disease (n = 38), clinically ill dogs without neoplasia (n = 47), and healthy dogs (n = 35). cfDNA levels and clinical data were compared among groups, and prognostic analyses were performed within the neoplastic group. Furthermore, continual cfDNA measurements were performed during the chemotherapy of six dogs with lymphoma. Dogs with neoplasia showed significantly higher cfDNA concentrations than dogs without neoplasm, and the cfDNA oncentration in the lymphoid neoplasia group was significantly elevated among all neoplastic groups. Dogs with neoplasia and a plasma cfDNA concentration above 1,247.5 μg/L had shorter survival rates than those with levels below this threshold (26.5 vs. 86.1%, respectively, P < 0.05). In cases with complete remission in response to chemotherapy, the cfDNA concentration was significantly decreased compared with the first visit, whereas the cfDNA concentration was increased in cases with disease progression or death. Interestingly, a significant correlation was found between lymph node diameter and cfDNA concentration in dogs with multicentric lymphoma (R2 = 0.26, P < 0.01). These data suggest that changes in cfDNA concentration could be used as a diagnostic biomarker for canine neoplasia. Furthermore, increased plasma DNA levels might be associated with shorter survival time, and cfDNA concentrations may reflect the response to chemotherapy.

Background: this study aimed to identify potential biomarkers for the screening and therapeutic monitoring of sepsis in canine pyometra and correlations with clinical parameters. Samples were collected from a total of 90 dogs with pyometra and 26 healthy female controls. The levels of inflammatory biomarkers and clinical parameters recorded in the dogs with pyometra at presentation were compared with those in the healthy subjects. In addition, consecutive samples from 22 dogs with surgically corrected pyometra and nine healthy controls, were compared before and after ovariohysterectomy. Results: significant leucocytosis, anaemia, hyperglobulinaemia, hypoalbuminaemia, and elevated activities of the alanine aminotransferase and alkaline phosphatase (ALP) enzymes, were observed in the dogs with pyometra at presentation. Moreover, the concentrations of acute inflammatory proteins of C-reactive protein (CRP) and serum amyloid A (SAA), as well as those of cell-free DNA (cfDNA), were significantly higher in the dogs with pyometra. cfDNA was the most sensitive biomarker for systemic inflammation, based on the receiver operating characteristic curve analysis (area under the curve = 0.959). After surgical removal of the inflamed uterus, leucocyte and red blood cell counts, cholesterol, albumin, globulin levels, and the ALP activity significantly decreased. The levels of inflammatory parameters such as interleukin-6 (IL-6), high-mobility group box 1 (HMGB1), and procalcitonin (PCT) also significantly decreased after surgical treatment. Conclusions: these findings indicate that cfDNA, CRP, and SAA have the potential to be used as clinical biomarkers for screening canine sepsis, whereas PCT, IL-6, and HMGB1 may be useful biomarkers for the therapeutic monitoring of canine sepsis.

Bacillus amyloliquefaciens is a gram-positive bacterial species that is utilised as a probiotic in humans and animals. There are no reports of infective endocarditis (IE) in dogs. An 8-year-old, spayed, female Maltese presented with a 1-month history of fever, depression, weight loss, and hindlimb lameness. Laboratory test results indicated non-regenerative anaemia, neutrophilia, hyperglobulinemia, and proteinuria. Echocardiography revealed vegetation on the septal leaflet of the mitral valve and thromboemboli in the left atrium. Consecutive blood culture results revealed that the blood samples were consistently positive for Bacillus amyloliquefaciens, which is generally considered a probiotic bacterial species for animals. Broad-spectrum antibiotics (amoxicillin-clavulanic acid and cefotaxime) and anticoagulants (clopidogrel and rivaroxaban) were administered for 4 months. The clinical signs were responsive to antibiotic treatment. After 4 months, the dog was no longer febrile and the size of the thromboemboli in the left atrium had decreased. Bacteria were no longer isolated in blood cultures after antibiotic therapy. To the best of our knowledge, this is the first case report of canine IE caused by bactaeremic infection with Bacillus amyloliquefaciens.

A 1‐year‐old, castrated, male, domestic short‐haired cat with pruritic, multifocal, crusted ulceration of the skin over the dorsal aspect of the neck and scapulae was presented. The cat also had a history of depression and anorexia. A causative agent for the lesion was not identified on a general dermatological examination. Histopathology revealed diffuse epidermal ulceration and loss with replacement by neutrophilic inflammation and necrotic debris. Idiopathic ulcerative dermatitis (IUD) was diagnosed based on history, physical examination and histopathology. To prevent self‐trauma and secondary bacterial infection, light bandages and glucocorticoid ointment were applied. After a month of management, the lesions markedly improved. Approximately 3 months after the initial presentation, the cat died; necropsy confirmed an IUD and non‐effusive (dry form) feline infectious peritonitis (FIP). This report describes a rare case of IUD in a cat with concurrent FIP. However, no association between IUD and FIP was found.

This report describes the first clinical case of a transfusion-associated Mycoplasma haemocanis infection in a dog in Korea. A 6-year-old male Maltese underwent a red blood cell transfusion for idiopathic immune-mediated hemolytic anemia. Eighteen days after the blood transfusion, the recipient’s packed cell volume decreased and basophilic organisms were found on erythrocytes. A polymerase chain reaction and sequential analysis showed that both the donor dog and recipient dog had M. haemocanis. Six weeks after doxycycline administration, no organisms were detected and the recipient’s anemia had improved.

Background The association of gut microbiota with cancer etiology and prognosis has been demonstrated in humans and rodents but has not been studied in dogs with different types of tumors. Hypothesis/Objectives To analyze microbiome composition according to tumor progression based on metastasis, recurrence, and therapeutic response in canine tumors. Animals Thirty‐two client‐owned dogs were divided into 3 groups: healthy (n = 9), with lymphoma (n = 12), with nonlymphoid tumors (n = 11). Methods Retrospective case series included animals were divided into subgroups according to the nature and severity of their tumors. Feces were screened for the 16S rRNA gene. Results Overall, alpha diversity was significantly reduced in dogs with tumors (n = 23; 12 lymphoid and 11 nonlymphoid) compared to healthy dogs (n = 9). Bacteroides had lower abundance in canine tumors at genus level. Staphylococcus showed significantly reduced abundance in dogs with aggressive tumor progression. Higher white blood cell (WBC) and neutrophil counts and lower hematocrit were significant in dogs with aggressive tumor. Spearman's rank correlation coefficient analysis revealed several measurements that showed moderate to strong correlations, including Coprococcus with total WBC count, neutrophil count, and hematocrit in the aggressive tumor group, and Saccharimonas with serum albumin and sodium concentration in all tumor dogs. Conclusion and Clinical Importance The diversity of the gut microbiome was significantly reduced in dogs with tumors compared to healthy dogs. Correlations were found between changes in blood measurements and changes in microbiome composition in relation to paraneoplastic syndrome.

Canine T-zone lymphoma (TZL) is a mature T-cell lymphoma in dogs. The diagnosis and sub-classification are impossible without biopsy or immunophenotyping by flow cytometry. An 11-year-old, spayed, female Golden Retriever presented with lymph node enlargement. Clinical examination was consistent with canine multicentric lymphoma. However, immunophenotyping revealed positive for CD3, CD4, CD5, CD8, CD21, TCRαβ, and MHCII but negative for CD34, CD45, CD79a, and TCRγδ. Histopathology revealed lymphocytes expanding to the cortex-preserving architecture and thinning of the nodal capsule, and CD3 positive but PAX-5 negative. Owing to the indolent nature of TZL, careful monitoring approach without clinical intervention was utilized.

Lymphoma is a severe condition characterized by the proliferation of neoplastic lymphoid cells. A 4-year-old female mongrel dog presented with solitary lymph node enlargement. Significant right prescapular lymphadenopathy and abdominal enlargement were observed during physical examination. A complete blood count revealed lymphocytosis, and a peripheral blood smear revealed lymphoblastosis and Mott cells. Fine needle aspiration cytology (FNAC) of the right prescapular lymph node revealed a predominant population of lymphoblasts and Mott cells. Based on the FNAC and blood smear results, the patient was diagnosed with leukemic state multicentric B-cell lymphoma with Mott cell differentiation. Subsequent PCR for antigen receptor rearrangement and flow cytometry revealed that the patient exhibited cross-lineage rearrangement (CLRA) and lineage infidelity (LI), respectively. CHOP-based chemotherapy was initiated, however, the patient’s disease was progressive. The patient died three months after the initial presentation. Mott cell differentiation in canine B-cell lymphoma (MCL) has rarely been reported in the veterinary literature and seems to show an unusual clinical course. To the best of our knowledge, no reports of MCL with CLRA and LI exist. We report the clinical features, diagnosis, and treatment of MCL with CLRA and LI.