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

Mitotic activity: A systematic literature review of the assessment methodology and prognostic value in canine tumors

One of the most relevant prognostic indices for tumors is cellular proliferation, which is most commonly measured by the mitotic activity in routine tumor sections. The goal of this systematic review was to analyze the methods and prognostic relevance of histologically measuring mitotic activity that have been reported for canine tumors in the literature. A total of 137 articles that correlated the mitotic activity in canine tumors with patient outcome were identified through a systematic (PubMed and Scopus) and nonsystematic (Google Scholar) literature search and eligibility screening process. Mitotic activity methods encompassed the mitotic count (MC, number of mitotic figures per tumor area) in 126 studies, presumably the MC (method not specified) in 6 studies, and the mitotic index (MI, number of mitotic figures per number of tumor cells) in 5 studies. A particularly high risk of bias was identified based on the available details of the MC methods and statistical analyses, which often did not quantify the prognostic discriminative ability of the MC and only reported P values. A significant association of the MC with survival was found in 72 of 109 (66%) studies. However, survival was evaluated by at least 3 studies in only 7 tumor types/groups, of which a prognostic relevance is apparent for mast cell tumors of the skin, cutaneous melanoma, and soft tissue tumor of the skin and subcutis. None of the studies using the MI found a prognostic relevance. This review highlights the need for more studies with standardized methods and appropriate analysis of the discriminative ability to prove the prognostic value of the MC and MI in various tumor types. Future studies are needed to evaluate the influence of the performance of individual pathologists on the appropriateness of prognostic thresholds and investigate methods to improve interobserver reproducibility.

Retrospective evaluation of the neutrophil-to-lymphocyte ratio as a prognostic marker in cats with blunt trauma (2018-2021): 177 cases

OBJECTIVE

To investigate the utility of the neutrophil-to-lymphocyte ratio (NLR) as a prognostic marker in cats with blunt trauma.

DESIGN

Retrospective study from January 2018 to December 2021.

SETTING

University teaching hospital.

ANIMALS

Medical records of 177 cats admitted with blunt trauma were evaluated. History, clinical findings, blood cell count-based ratios, thoracic radiographs on presentation, and outcome were reviewed. The Animal Trauma Triage (ATT) score was assessed in each cat and classified as mild (1-3), moderate (4-7), and severe trauma (≥8). Forty-eight healthy blood donor cats served as the control population. NLR, neutrophil counts, and lymphocyte counts were compared between cats with blunt trauma and controls, and among trauma patients.

INTERVENTIONS

None MEASUREMENTS AND MAIN RESULTS: NLR, neutrophil counts, and lymphocyte counts significantly differ in cats with blunt trauma compared to controls (p < 0.001), and NLR was higher in patients with thoracic trauma (p = 0.044). Nonsurvivors had lower lymphocyte counts (p = 0.041), although those values do not appear to be clinically relevant. A significant increase in NLR was observed with increasing severity of trauma (p < 0.001). The NLR was not associated with the length of hospitalization, intensive care assistance, or mortality.

CONCLUSION

NLR is a widely available diagnostic tool, which can be used in addition to ATT to assess trauma severity, although in our study it was not predictive of the outcome.

Retrospective evaluation of the effect of acid suppressant drugs on leukocyte ratios in dogs with mast cell tumors

BACKGROUND

Acid suppressant drugs (ASDs) are commonly used to decrease gastric acid production, but some evidence exists that ASDs exert immunomodulatory effects. Such an effect has not been investigated in dogs for which ASDs are routinely prescribed.

HYPOTHESIS

Compared to naïve subjects, dogs treated with ASDs will exhibit differences in leukocyte ratios after treatment.

ANIMALS

Fifty-one dogs with mast cell tumors (MCTs).

MATERIALS AND METHODS

Dogs with MCT that were either AS naïve or treated with ASDs (i.e., histamine-2-receptor antagonists [H2RA] or proton pump inhibitors [PPI]) were included in this retrospective study. Subjects were categorized into 3 treatment groups (AS naïve, H2RA treated, and PPI treated), and leukocyte ratios (neutrophil:eosinophil, lymphocyte:monocyte, and neutrophil:lymphocyte [NLR]) were calculated before and after treatment. A mixed effects analysis of variance on ranks was used to assess differences in ratios between treatments, between pre- and post-treatment time points, and between pre- and post-time points for each treatment. Concurrent administration of antihistamines, corticosteroids, and chemotherapeutic drugs was assessed as a confounding factor.

RESULTS

Famotidine (n = 14/14) and omeprazole (n = 12/12) were the only H2RA and PPI used, respectively. Dogs receiving famotidine had a significant increase in median NLR from pre- to post-treatment (3.429; range, 1.417-15 to 5.631; range, 2.654-92; P < 0.01) compared to PPI treated or AS naïve dogs. No differences existed in chemotherapeutic drug or corticosteroid use between groups.

CONCLUSIONS

A significant difference in NLR was identified in famotidine treated dogs compared with omeprazole treated or AS naïve dogs.

Retrospective evaluation of hematological ratios in canine parvovirosis: 401 cases

BACKGROUND

The utility of neutrophil-to-lymphocyte ratio (NLR), platelet to-lymphocyte ratio (PLR) and monocyte-to-lymphocyte ratio (MLR) as prognostic indicators has not been investigated in canine parvovirosis (CPV).

HYPOTHESIS

To evaluate whether these hematological ratios obtained at hospital admission in CPV are associated with outcome or duration of hospitalization.

ANIMALS

Four hundred one client-owned dogs presented with CPV. Methods-Retrospective multicenter cohort study. Medical records were reviewed to identify dogs with CPV. Data regarding signalment, complete blood count at admission, duration of hospitalization and outcome were collected.

RESULTS

Of the 401 dogs included in the study, 336 (83.8%) survived to discharge. The median (25th and 75th percentiles) PLR in nonsurvivors (336.56 [159.84-635.77]) was significantly higher than in survivors (217.65 [117.67-389.65]) (P = .003). The area under the receiver-operating characteristic curve for nonsurvival was 0.615 (95% CI [0.593-0.691], P = .003). A cut off of 700 showed a 21.5% sensitivity and 90% specificity for nonsurvival. No association was observed between hospitalization duration and either hematological ratios or total WBC counts. The median (25th and 75th percentiles) lymphocyte count was below reference interval in all dogs and was significantly lower in the dogs which died (0.82 × 109 /L [0.5-1.87]) than in survivors (1.27 × 109 /L [0.73-2.22]) (P = .005). The median (25th and 75th percentiles) monocyte count however was lower in survivors (0.38 × 109 /L [0.29-1.59]), than in nonsurvivors (0.73 × 109 /L [0.1-2]) (P = .002).

CONCLUSIONS

Evaluation of PLR at hospital admission might be a useful marker of disease severity and could have prognostic value in dogs with CPV.

Atypical Mitotic Figures Are Prognostically Meaningful for Canine Cutaneous Mast Cell Tumors

Cell division through mitosis (microscopically visible as mitotic figures, MFs) is a highly regulated process. However, neoplastic cells may exhibit errors in chromosome segregation (microscopically visible as atypical mitotic figures, AMFs) resulting in aberrant chromosome structures. AMFs have been shown to be of prognostic relevance for some neoplasms in humans but not in animals. In this study, the prognostic relevance of AMFs was evaluated for canine cutaneous mast cell tumors (ccMCT). Histological examination was conducted by one pathologist in whole slide images of 96 cases of ccMCT with a known survival time. Tumor-related death occurred in 11/18 high-grade and 2/78 low-grade cases (2011 two-tier system). The area under the curve (AUC) was 0.859 for the AMF count and 0.880 for the AMF to MF ratio with regard to tumor-related mortality. In comparison, the AUC for the mitotic count was 0.885. Based on our data, a prognostically meaningful threshold of ≥3 per 2.37 mm2 for the AMF count (sensitivity: 76.9%, specificity: 98.8%) and >7.5% for the AMF:MF ratio (sensitivity: 76.9%, specificity: 100%) is suggested. While the mitotic count of ≥ 6 resulted in six false positive cases, these could be eliminated when combined with the AMF to MF ratio. In conclusion, the results of this study suggests that AMF enumeration is a prognostically valuable test, particularly due to its high specificity with regard to tumor-related mortality. Additional validation and reproducibility studies are needed to further evaluate AMFs as a prognostic criterion for ccMCT and other tumor types.

Evaluation of red blood cell distribution width, neutrophil-to-lymphocyte ratio, and other hematologic parameters in canine acute pancreatitis

OBJECTIVE

To determine if RBC distribution width (RDW), neutrophil-to-lymphocyte ratio (NLR), and other hematological parameters are associated with increased odds of in-hospital mortality, increased length of hospitalization (LOH), or disease severity as measured by the Canine Acute Pancreatitis Severity (CAPS) score in dogs with acute pancreatitis (AP).

DESIGN

Retrospective, multicenter study from January 2016 to August 2020.

SETTING

Four private emergency and specialty referral centers.

ANIMALS

On initial case search, 118 client-owned dogs were identified with a clinical diagnosis of AP. Out of these cases, 114 dogs met inclusion criteria, defined as sudden onset of ≥2 compatible clinic signs (lethargy, anorexia, vomiting, or abdominal pain), a specific canine pancreatic lipase concentration >400 μg/L, hospital admission, as well as CBC and serum biochemistry run within 48 hours of initial hospitalization. Disease severity was calculated and measured using the CAPS score, in addition to LOH and in-hospital mortality.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Clinical endpoints were in-hospital mortality, LOH, and disease severity, as evaluated by the CAPS score. Overall in-hospital mortality was 36.8%. NLR was significantly associated with survival, with a higher percentage being associated with an increased likelihood of nonsurvival (odds ratio: 1.1, 95% confidence interval: 1.0-1.2; P = 0.006, adjusted P = 0.04). Increased NLR was found to be significantly associated with a longer LOH based on the unadjusted P-value (P = 0.02) but was not statistically significant based on a P-value adjusted for multiple comparisons (P = 0.12). No significant associations were noted when RDW, platelet-to-lymphocyte ratio, WBC count, mean platelet volume, RDW-to-platelet ratio, or RDW-to-total serum calcium ratio was evaluated against outcome measures.

CONCLUSIONS

This study retrospectively evaluated the prognostic utility of several readily available hematological parameters in dogs hospitalized for AP. Dogs with an increased NLR may have a higher risk of in-hospital mortality and increased LOH, although future prospective studies are necessary to confirm these findings.

A Retrospective Comparative Evaluation of Selected Blood Cell Ratios, Acute Phase Proteins, and Leukocyte Changes Suggestive of Inflammation in Cats

Neutrophil-to-lymphocyte (NLR), monocyte-to-lymphocyte (MLR), and platelet-to-lymphocyte (PLR) ratios have been proposed as diagnostic and prognostic markers for neoplastic and inflammatory diseases in dogs and cats. The aim of this retrospective preliminary study was to evaluate the relationship between these ratios and markers of inflammation routinely measured in cats. A total of 275 cats were enrolled. Complete blood count, serum amyloid A (SAA), albumin, globulin, and albumin-to-globulin ratio (AGR) data were analyzed, as well as the presence of leukocyte alterations considered suggestive of inflammation (LAI: neutrophils left shift, toxic neutrophils, and reactive lymphocytes) evaluated in blood smears. The NLR and MLR correlated positively with SAA and globulins and negatively with albumin and AGR. Higher NLR and MLR were found in cats with increased SAA and globulins and decreased albumin and AGR. The PLR correlated negatively with albumin and AGR. A higher PLR was found in cats with hypoalbuminemia. Cats with LAI had higher NLR, MLR, and PLR. In cats with no changes in parameters indicative of inflammation, 11.25, 0.42, and 528.3 were identified as upper limits for NLR, MLR, and PLR, respectively. In conclusion, the NLR, MLR, and PLR act as good inflammatory markers easily evaluated by routine hematology.

The Prognostic Role of Preoperative Hematological and Inflammatory Indices in Canine Appendicular Osteosarcoma

Hematological indices play a prognostic role in human osteosarcoma (OSA), but data are limited in dogs. The aim of this retrospective multicentric cohort study was to investigate the prognostic significance of pre-operative hematological/inflammatory indices in a cohort of client-owned dogs with appendicular OSA receiving standardized treatment. Cut-offs associated with progression-free survival (PFS) for pre-operative hematological values/ratios were established using the minimal p-value approach. Historical prognostic factors were also assessed. Statistical analyses were performed for the whole population and after the exclusion of sighthounds. Fifty-nine dogs were included (13 were sighthounds). Multivariable analysis revealed that a low neutrophil count (<4.37 × 109/L, HR0.28, CI 95% 0.13-0.61, p = 0.001), a high red blood cell count (≥7.91, HR3.5, CI 95% 1.56-7.9, p = 0.002), and a proximal humerus location (HR3.0, CI 95% 1.48-6.1, p = 0.002) were associated with shorter PFS. In the sighthound-only population, only OSA location was significantly associated with PFS in univariable analysis. When sighthounds were excluded, a low neutrophil count, a low monocyte count, and a proximal humerus location were associated with shorter PFS, in multivariable analysis. Neutrophil count and possibly monocyte and red blood cell counts can be useful prognostic markers in canine OSA treated with amputation and adjuvant carboplatin. However, not all indices are appropriate in sighthounds.

Neutrophil to lymphocyte ratio and principal component analysis offer prognostic advantage for dogs with mammary tumors

Introduction

In veterinary medicine, cancer is the leading cause of death in companion animals, and mammary gland tumors represent the most common neoplasm in female dogs. Several epidemiological risk factors, such as age, breed, hormones, diet, and obesity have been reported to be relevant for canine mammary tumors. Nowadays, the gold standard for diagnosis of canine mammary tumors is the pathological examination of the suspected tissue. However, tumor grade can only be assessed after surgical removal or biopsy of the altered tissue. Therefore, in cases of tumors that could be surgically removed, it would be very helpful to be able to predict the biological behavior of the tumor, before performing any surgery. Since, inflammation constitutes part of the tumor microenvironment and it influences each step of tumorigenesis, cellular and biochemical blood markers of systemic inflammation, such as the neutrophil to lymphocyte ratio (NLR) and the albumin to globulin ratio (AGR) have been proposed as prognostic factors for human cancer development. The NLR and the AGR have not been explored enough as prognostic factors for cancer development in veterinary medicine.

Methods

To determine the prognostic value of NLR in canine mammary tumors, clinical records including biochemistry and hematological studies of female dogs with mammary tumors and of control healthy dogs, were used to determine the pre-treatment NLR and AGR. Other clinical data included age, breed, tumor size, histological tumor grade, and survival time after surgery.

Results and discussion

It was found that a higher pre-treatment NLR value (NLR > 5) associates with less survival rate. In contrast, the AGR did not show any predictive value on the malignancy of the tumor. However, by combining the NLR with AGR, age of the dog, and tumor size in a principal component analysis (PCA), the grade of the tumor and survival after surgery could be appropriately predicted. These data strongly suggest that pre-treatment NLR values have a prognostic value for the survival rate after surgery of dogs with mammary tumors.

Clinical and Clinicopathologic Discriminators Between Canine Acute Monocytic Ehrlichiosis and Primary Immune Thrombocytopenia

Acute canine monocytic ehrlichiosis due to Ehrlichia canis (aCME), and primary immune thrombocytopenia (pITP) are major differentials for dogs presented with thrombocytopenia, and the two diseases may clinically overlap. The aim of this study was to compare dogs diagnosed with naturally occurring aCME and pITP, to establish potentially useful clinical and clinicopathologic discriminators. A clinical record-based retrospective study was performed in 35 dogs diagnosed with aCME and 29 dogs with pITP. Dogs with aCME were significantly younger, and were more likely to experience depression or lethargy, anorexia, body weight loss, fever, lymphadenomegaly, tick infestation, and ocular discharge on admission, compared to dogs with pITP. In contrast, dogs with pITP presented more frequently with overt bleeding and had a significantly higher bleeding score compared to dogs with aCME. Dogs with aCME were more likely to be anemic and hypoalbuminemic on presentation compared to dogs with pITP. Dogs with pITP had higher white blood cell and neutrophil counts as well as lower platelet counts than dogs with aCME and were more likely to present with leukocytosis, neutrophilia and monocytosis. These clinical, hematological, and biochemical findings may be helpful discriminators between aCME and pITP, on the understanding that they will be interpreted in the context of disease-specific testing.

Treatment of multiple synchronous canine mast cell tumours using intratumoural tigilanol tiglate

Mast cell tumours (MCTs) are common canine skin neoplasia. While they generally occur as single tumours, multiple synchronous MCTs (msMCTs) of de novo/non-metastatic origin are reported in a proportion of the patient population. Where there is no evidence of metastasis or lymphatic spread, MCTs are effectively controlled by surgery and other local therapies. However, treatment of de novo msMCTs can be more challenging, especially when they occur in surgically difficult locations. Here, we report the use of tigilanol tiglate, a novel small molecule registered as a veterinary pharmaceutical for the local treatment of non-metastatic MCTs, in the treatment of patients with msMCTs presenting at three Australian specialist referral centres. We also present a meta-analysis of the literature to provide a better understanding of the prevalence of canine msMCTs. Notably, nine patients with a total of 32 MCTs were treated during the study. A complete response was recorded in 26 (81%) of the individual MCTs on Day 28 after a single tigilanol tiglate injection. Of the 6 initially non-responsive MCTs, one achieved a complete response after a further tigilanol tiglate treatment. A complete response was reported at 6 months in all 22 of the tumours that were evaluable and that had recorded a complete response at Day 84. For the literature meta-analysis, 22 studies were found with prevalence estimates of msMCTs ranging from 3 to 40%; when combined, these studies yielded 3,745 patients with a prevalence of 13% (95% CI 10; 16). Overall, the results demonstrate the utility of intratumoural tigilanol tiglate as an option for the treatment of multiple MCTs where multiple surgical resections would have been required.

The impact of peripheral blood cell ratios in dogs with diffuse B-cell small lymphocytic lymphoma treated with CHOP protocol

In this study, pre-chemotherapy hematological values of 14 dogs diagnosed with diffuse B-cell small lymphocytic lymphoma were compared with the hematological data of 26 healthy dogs. Neutrophil/lymphocyte ratio (NLR), lymphocyte/monocyte ratio (LMR), platelet/lymphocyte ratio (PLR) and platelet/neutrophil ratio (PNR) were evaluated between two groups. Anemia and an increased total leukocyte count were observed in dogs with lymphoma compared to healthy ones. The PNR value was found to be significantly lower in dogs with lymphoma, It was concluded that more comprehensive studies studies are needed to clearly understand the diagnostic and prognostic importance of hematological parameters in B-cell small lymphocytic lymphoma of dogs.

Peripheral blood eosinophilia in dogs: Prevalence and associated diseases

BACKGROUND

Canine eosinophilia has not been evaluated over the last two decades. As in human local differences, changes in the prevalence and associated diseases over time can be expected.

OBJECTIVE

This study aims to determine the prevalence and causes of marked blood eosinophilia in dogs.

METHODS

Retrospective study. A total of 317 clinical histories of dogs with an eosinophil concentration > 1.5 × 109 /L (marked eosinophilia) between 2013 and 2017 were evaluated. Patients were allocated to 10 groups according to their major clinical findings.

RESULTS

Eosinophilia was present in 1,592 of 10,829 dogs (14.7%); it was mild (0.8-1.49 × 109 /L) in 78.4%, moderate (1.5 - 4.9 × 109 /L) in 20.5% and severe (> 5 × 109 /L) in 1.1% of cases. Rottweilers were overrepresented (16.1%). Of 317 cases with marked eosinophilia, 19.6% had neoplasia, 19.1% gastrointestinal disorders, 13.6% health check, 10.4% endoparasites, 6% respiratory, 5.4% neurologic, 5.4% dermatologic, 4.8% urogenital, 3.2% endocrine disorders and 12.6% miscellaneous. Lymphomas (29%) and mast cell tumours (12.9%) were the most frequent tumours in the neoplasia group. A total of 72.6% of tumour-bearing dogs were older than 8 years, while 63.6% of dogs had endoparasites, and 86% of apparently healthy dogs were younger than 5 years. Eosinophilia was significantly higher in patients with respiratory disorders (p < 0.0146). Leukocytosis was found in 50.2% of cases.

CONCLUSION

Malignancy was the most common cause of marked blood eosinophilia in older dogs and endoparasitism in younger dogs. Eosinophilia was common in apparently healthy young dogs and may be related to undiagnosed parasitic infestations.

Analytical variability and uncertainty in canine leukocyte ratios obtained with manual counts

BACKGROUND

This study aimed to determine the analytical imprecision of calculated neutrophil to lymphocyte (NLR) and lymphocyte to monocyte ratios generated from manual differential white blood cell (WBC) counts in peripheral blood smears, and to describe how to report the uncertainty around a single WBC ratio result. No information on the analytical imprecision of WBC ratios in dogs is available.

METHODS

Coefficient of variations (CVs) of paired readings of one operator on 105 smears (intraoperator variability) and of three operators on 301 smears (interoperator variability) were calculated. The interoperator agreement was examined with the Fleiss' kappa coefficient (κ). Observed total errors (TEos), expanded measurement of uncertainty (EMU) and reporting intervals (RIs) were also calculated.

RESULTS

Median CVs ranged from 3.14 to 28.28 (intraoperator) and from 5.39 to 53.85 (interoperator). No agreement among operators was found around the cut-offs. TEos were higher than allowable total errors in 32%-88% of smears. EMU ranged from 0.10 to 1.13. According to the RI, the calculated WBC ratios should be rounded to the nearest 10.

CONCLUSION

WBC ratios should be interpreted cautiously in dogs. The EMU should be reported to make the clinician aware of the uncertainty of these parameters. For example, an NLR result of 17 is needed to have high confidence that the result is above a cut-off of 6.

Canine Melanoma Immunology and Immunotherapy: Relevance of Translational Research

In veterinary oncology, canine melanoma is still a fatal disease for which innovative and long-lasting curative treatments are urgently required. Considering the similarities between canine and human melanoma and the clinical revolution that immunotherapy has instigated in the treatment of human melanoma patients, special attention must be paid to advancements in tumor immunology research in the veterinary field. Herein, we aim to discuss the most relevant knowledge on the immune landscape of canine melanoma and the most promising immunotherapeutic approaches under investigation. Particular attention will be dedicated to anti-cancer vaccination, and, especially, to the encouraging clinical results that we have obtained with DNA vaccines directed against chondroitin sulfate proteoglycan 4 (CSPG4), which is an appealing tumor-associated antigen with a key oncogenic role in both canine and human melanoma. In parallel with advances in therapeutic options, progress in the identification of easily accessible biomarkers to improve the diagnosis and the prognosis of melanoma should be sought, with circulating small extracellular vesicles emerging as strategically relevant players. Translational advances in melanoma management, whether achieved in the human or veterinary fields, may drive improvements with mutual clinical benefits for both human and canine patients; this is where the strength of comparative oncology lies.

Diagnostic and prognostic value of peripheral blood leucocyte ratios in sick cats

The objective of this study was to assess the diagnostic and prognostic utility of feline neutrophil-to-lymphocyte (NLR) and lymphocyte-to-monocyte ratios (LMR) in a variety of underlying diseases. Five-year medical records from cats presenting to the internal medicine unit of a veterinary teaching hospital were retrospectively reviewed. Cats were considered for inclusion based on complete medical records. ADVIA 120 was used for the complete blood counts; the NLR and LMR were calculated by dividing the absolute numbers of the respective leucocytes. Two hundred and nineteen sick and 20 healthy cats were included in the study. The median NLR and LMR were significantly (P < 0.05) elevated and decreased, respectively, in cats with infectious, neoplastic and chronic kidney diseases compared to controls. Additionally, cats with neoplasia had significantly higher median NLR compared to cats with urinary tract and gastrointestinal diseases. Non-survivors had significantly higher NLR and lower LMR compared to survivors. Both ratios had suboptimal prognostic performance for the outcome of sick cats (NLR sensitivity: 37.9%, specificity: 86.4%; LMR sensitivity: 69.0%, specificity: 61.0%). Many different disease categories were associated with increased NLR and decreased LMR compared to controls, but the overall prognostic performance of the two leucocyte ratios was suboptimal.

Evaluation of prognostic impact of pre-treatment neutrophil to lymphocyte and lymphocyte to monocyte ratios in dogs with oral malignant melanoma treated with surgery and adjuvant CSPG4-antigen electrovaccination: an explorative study

The role of systemic inflammation in cancer's progression has been widely investigated, especially in melanoma in humans. Pre-treatment leukocyte counts and ratios play a recognized prognostic role in several types of malignancies, but no information is available regarding canine oral malignant melanoma (COMM). The purpose of this explorative retrospective study was to investigate the prognostic impact of pre-treatment neutrophil to lymphocyte (NLR) and lymphocyte to monocyte (LMR) ratios in dogs with oral malignant melanoma that underwent surgical resection and immunotherapy with adjuvant CSPG4-antigen electrovaccination. Thirty-nine dogs with histologically confirmed oral melanoma and with available pre-treatment haematological analyses, performed at maximum 60 days before the first treatment, were retrospectively enrolled. Statistical analysis was performed to explore possible correlations among NLR and LMR with age, clinical stage, tumour pigmentation, tumour size, nuclear atypia, mitotic index, Ki67, CSPG4 expression, ulceration, bone invasion and excision margins status. The impact of NLR and LMR on overall survival time (OST) was explored among various ratio cut off and across different time points with Kaplan-Meier method. No significant relationship was identified between leukocytes ratios and histological parameters, CSPG4 expression, excision margin status, age, tumour size and clinical stage. NLR and LMR did not display a prognostic impact on the survival time of the entire population. Pre-treatment leukocyte ratios may not represent a useful prognostic factor in dogs with oral melanoma, especially in absence of distant metastatic disease.

Leukocytes Ratios in Feline Systemic Inflammatory Response Syndrome and Sepsis: A Retrospective Analysis of 209 Cases

Simple Summary

Feline sepsis is a life-threatening syndrome in which blood diagnostic and prognostic markers are limited. We investigated the differences in neutrophil-to-lymphocyte ratio and other white-blood-cell ratios between healthy and sick cats (systemic inflammation (SIRS) and/or septic cats) and then the use of these ratios as prognostic markers. This study included 76 healthy cats (blood-donors), 54 cats with SIRS and 79 cats with sepsis. A cat with an NLR > 4.53 had a 44-fold chance to have SIRS or sepsis, although only BLR and BNLR were different between SIRS and sepsis groups. The NLR has been shown as a prognostic marker in sick cats. This is a novel investigation about leukocyte ratios in the cat, and the NLR may be used as a prognostic parameter in cats with SIRS or sepsis, and BLR and BNLR demonstrate themselves as promising tools in differentiating SIRS from sepsis.

Abstract

Sepsis is a challenging condition in which hematological prognostic and diagnostic markers in cats are limited. The aims of this study were to test if there are any differences in leukocyte ratios (NLR, BLR and BNLR) between healthy, SIRS and septic cats (sick cats), and if, within sick cats, NLR, BLR and BNLR may be prognostic markers. A retrospective medical database study included 76 healthy cats (blood-donors), 54 SIRS and 79 septic cats. SIRS group was defined if cats fulfilled SIRS criteria. Sepsis was confirmed with an infectious focus on cytology or a positive culture for bacterial infection. Leukocyte ratios were compared among the three study groups and between survivors and non-survivors in sick cats. NLR resulted significantly higher in the sick group compared to healthy cats (p < 0.0001), although NLR was not different between SIRS and sepsis. An NLR > 4.53 had a sensitivity of 76% and a specificity of 93.4% to detect SIRS/sepsis (OR 44.8 95%CI 17–107). Only BLR and BNLR were significantly different between SIRS and sepsis. NLR was associated with mortality in the sick group (p = 0.04). Although NLR resulted higher in sick cats than healthy, BLR and BNLR demonstrated as promising tools in differentiating SIRS from sepsis. NLR was associated with mortality in sick cats.

Blood neutrophil-to-lymphocyte ratio (NLR) as a diagnostic marker in dogs with chronic enteropathy

Few routinely available biomarkers are clinically useful in assessing dogs with chronic enteropathy (CE) and aid in CE subclassification. The diagnostic potential of the blood neutrophil-to-lymphocyte ratio (NLR) has not been evaluated in canine CE. We evaluated the NLR in 93 dogs with CE (no steroid treatment for ≥2 wk prior) and tested for an association with clinical, clinicopathologic, and histologic characteristics and also with CE subclassification. NLR was significantly higher in CE dogs with severe clinical disease than dogs with mild clinical disease (p = 0.047). Hypoalbuminemia (p < 0.001), but not hypocobalaminemia, was associated with higher NLRs. NLR was correlated with fecal alpha₁-proteinase inhibitor concentrations (ρ = 0.47) and the serum-to-fecal alpha₁-proteinase inhibitor ratio (ρ = -0.48; both p < 0.001) but not with serum or fecal inflammatory markers nor with the overall histologic score (all p > 0.05). Dogs with steroid- or other immunosuppressant-responsive (IRE) or nonresponsive enteropathy (NRE) had significantly higher NLRs (median: 7.3) than dogs with food-responsive enteropathy (FRE; median: 3.0; p = 0.003), and a NLR ≥5.5 best distinguished both groups of dogs. No difference in NLR was detected between dogs with IRE and dogs diagnosed with NRE. These findings suggest that leukogram changes (i.e., NLR) could be clinically useful in canine CE, and that neutrophils might play a role in the systemic inflammatory response associated with canine CE. The NLR can be easily assessed on routine hematology and can potentially aid in the subclassification of dogs with CE based on the response to treatment.

Prognostic impact of clinical, haematological, and histopathological variables in 102 canine cutaneous perivascular wall tumours

Identification of prognostic factors for perivascular wall tumours (PWTs) is desirable to accurately predict prognosis and guide treatment. 100 and two dogs with surgically excised PWTs without distant metastasis were retrospectively enrolled in this multi-institutional study, and the impact of pre-treatment leukocyte parameters, clinical and histopathological variables on local recurrence (LR) and overall-survival time (OST) were evaluated. Increasing values of white blood cell count (WBCC), neutrophil count (NC) and neutrophil-to-lymphocyte ratio (NLR) were significantly correlated with the hazard of LR in univariate analysis. WBCC and NC remained prognostic when adjusted for margins, grade, tumour size, location and skin ulceration, but lost their significance when adjusted for mitotic index and necrosis, whilst NLR remained prognostic only when close margins where categorised as infiltrated. Castrated males had a higher hazard of LR than intact males in univariate analysis, but significance was lost in multivariate models. Ulcerated PWTs and those located on the distal extremities had a higher hazard of LR both in univariate and multivariate analysis. Histological grade, necrosis, mitotic count, and infiltrated margins were all associated with LR both in univariate and multivariate analysis. Boxer breed, older age, ulceration, grade III, necrosis >50% and higher mitotic count were correlated with shorter OST, although breed and age lost their significance in multivariate analysis. Prognostication of surgically excised PWTs should be based on both clinical and histopathological variables. If validated in further studies, leukocyte counts and NLR may aid the clinician in identifying dogs at higher risk of LR before treatment.

Peripheral blood cell ratios as prognostic factors in canine diffuse large B-cell lymphoma treated with CHOP protocol

Diffuse large B-cell lymphoma (DLBCL) is the most common haematopoietic tumour in dogs and recognized as clinical model for its human counterpart. Recently, neutrophil-to-lymphocyte (NLR) and lymphocyte-to-monocyte (LMR) ratios have been shown to predict time-to-progression (TTP) and lymphoma-specific survival (LSS) in dogs with DLBCL treated with CHOP-based chemotherapy. We retrospectively evaluated in 59 dogs diagnosed with DLBCL the prognostic value of haematological parameters and derived ratios: NLR, LMR, platelet-to-lymphocyte (PLR) and platelet-to-neutrophil (PNR) ratios for TTP, LSS and associated secondary end-points (time-to-progression-rate [TTPR] and lymphoma-specific survival-rate [LSSR]) as rates at 180 and 365 days. PNR is an independent prognostic marker (p ≤ .001) for TTPR/180 and 365 days, dogs with a PNR above 0.032 were more likely to progress before 180 days (sensitivity 46.5%, specificity 87.5%, p = .004). On univariate analysis, NLR showed a prognostic significance for LSSR/180 (p = .006) and LSSR/365 (p = .009). A baseline NLR value below 7.45 was positively associated with survival at 180 days (sensitivity 52%, specificity 85.3%, p = .025). The presence of substage b, was associated with early progression and decreased survival at 180 days (p = .031). Anaemia significantly reduced LSSR at 365 days (p = .028). This is the first study evaluating PLR and PNR in canine DLBCL and demonstrates that PNR could be a predictor of early lymphoma progression. Since peripheral blood cell composition can be affected by several non-oncological causes, the development of larger multicenter studies with homogeneous inclusion criteria could help to better determine the true predictive values of blood cell ratios in dogs' DLBCL treated with CHOP chemotherapy.

Are Leukocyte and Platelet Abnormalities and Complete Blood Count Ratios Potential Prognostic Markers in Canine Sepsis?

Background: Sepsis is a common disease in which early diagnosis and prognosis assessment are the main aims in order to arrange a prompt and effective treatment. Objectives: (1) To compare leukogram parameters (WBC, segmented and band neutrophils, lymphocytes, monocytes), platelet count (PLT), mean platelet volume (MPV), and some leukocyte/platelet ratio such as NLR, NBNLR, PLR, and MLR between dogs with systemic inflammatory response syndrome (SIRS) and sepsis. (2) To investigate any difference in the trend of these latter parameters between survivors and non-survivors septic dogs. Animals: 57 dogs with confirmed sepsis and 57 dogs with non-septic SIRS. Methods: A review of the medical records was conducted in order to find dogs with sepsis. Sepsis was defined as the presence of an infectious focus with fulfillment of systemic inflammatory response syndrome criteria (SIRS). Septic dogs had to have a CBC at admission and another CBC within 48 h from the previous timepoint. Purebreds with CBC breed-related abnormalities were excluded, together with dogs without confirmed sepsis and dogs with only a single CBC. NLR, NBNLR, PLR, and MLR were calculated. Univariate analysis of all blood parameters studied was assessed between SIRS and septic dogs. Generalized Estimating Equations models for repeated measures were used to test if the blood parameters studied were modified between survivors and non-survivors in the septic group. Results: Septic dogs had lower median segmented neutrophils count and NLR compared to SIRS dogs (p = 0.02 and p = 0.04, respectively). Lastly, septic dogs had a higher prevalence of toxic neutrophil than SIRS dogs (p = 0.01). We found that for a 1-unit increase of PLR and MLR, the risk of death increased by 50.5 and 60%, respectively. Conclusion and Clinical Importance: Evaluation of NLR at hospital admission may be a useful marker of inflammation, although it showed low sensitivity in differentiating SIRS and septic dogs. The monitoring of some CBC parameters, especially PLR and MLR may be useful in the establishment of prognosis in septic dogs.

Prognostic utility of preoperative neutrophil-lymphocyte ratio in cats with malignant mammary tumors

Although studies have determined the neutrophil-lymphocyte ratio (NLR) to be a useful prognostic predictor in various human cancers, little is known regarding its preoperative prognostic significance in feline mammary tumors (FMTs). Thus, the present study aimed to determine the prognostic utility of preoperative peripheral blood NLR in malignant FMTs. Accordingly, medical records of 34 cats that had undergone mastectomy were searched, after which those histopathologically confirmed to have malignant FMTs were included. Univariate analysis was used to determine the effect of each variable on one-year survival time. Factors determined to be significant during univariate analysis were subsequently included for multivariate analysis. Receiver operating characteristic analysis was used to assess the accuracy of the tests for predicting one-year survival. Univariate analysis showed that a high NLR and large tumor size were significantly associated with shorter survival times (P < 0.01, for both). No significant differences in other factors were observed. Multivariate analysis showed that a high NLR (hazard ratio, 25.03; 95% confidence interval, 2.98-210.40; P < 0.01), but not tumor size and age, was an independent prognostic factor for poor outcomes. The sensitivity and specificity of the NLR (cut-off, 5.67) for predicting one-year survival were 93.8% and 88.9%, respectively. This study suggests that the NLR could potentially be used as a preoperative prognostic factor in FMTs. Preoperative NLR may help to establish therapeutic modalities by allowing prognostic evaluation among cats with mammary tumors.

Neutrophil-to-Lymphocyte Ratio (NLR) in Canine Inflammatory Bowel Disease (IBD)

Inflammatory bowel disease (IBD) is a multifactorial chronic inflammatory disorder leading to structural changes in the intestinal wall. In humans, the neutrophil-to-lymphocyte ratio (NLR) has been proposed as a promising marker of IBD. This study evaluated the possible clinical and prognostic significance of the NLR in dogs with IBD. This retrospective study enrolled 41 dogs diagnosed with IBD presented to University of Pisa from January 2017 to January 2018. For each dog, age, sex, canine chronic enteropathy clinical activity index (CCECAI), endoscopic and histopathological grading were recorded. Complete blood count, serum total protein, albumin, cholesterol, and C-reactive protein at the time of endoscopy were recorded. A control group (CG) of healthy dogs from a blood donor database was built. NLR was calculated for both IBD and CG as the ratio between absolute neutrophils and lymphocytes. Presence of crypt distension, lacteal dilation (LD), mucosal fibrosis, intraepithelial lymphocytes was recorded. Follow-up information was obtained from electronic medical records and dogs were classified as responders and non-responders based on CCECAI variation between admission and the first recheck. IRE dogs showed higher NLR compared to healthy dogs. NLR correlated negatively with total protein, albumin, and cholesterol and correlated positively with CCECAI. Dogs with LD showed higher NLR than dogs without LD. Non-responders showed higher NLR compared to responders. In conclusion, as in IBD human patients, the NLR acts as an inflammatory marker providing further information on severity of the disease and could be useful in predicting treatment response.

Refining the "double two-thirds" rule: Genotype-based breed grouping and clinical presentation help predict the diagnosis of canine splenic mass lesions in 288 dogs

Prediction of the likely histopathological diagnosis of canine splenic masses can guide appropriate decision-making. This study explores the predictive effect of breed and clinical presentation on the diagnosis of a canine splenic mass. Records from the Royal Veterinary College, United Kingdom (2007-2017) were reviewed. Dogs with a histopathologic or cytologic diagnosis from a splenic mass, or imaging findings consistent with disseminated metastatic disease, were included. Signalment, physical examination, haematology results, imaging findings and pathology reports were recorded. Breeds were grouped according to several permutations of their phenotype and then by clustering of breeds based on single nucleotide polymorphism analysis. Binary logistic regression was performed to identify predictors of malignancy and haemangiosarcoma. Two hundred and eighty-eight dogs were identified: 27% female and 63% male, 21% entire and 79% neutered; German Shepherd was the most common breed (11%). Median age was 10 years and median bodyweight 25 kg. Thirty-eight percent of dogs presented with haemoabdomen; a splenic mass was found incidentally in 28%. Sixty percent had a malignant tumour of which haemangiosarcoma comprised 66%. On multivariable analysis, genotype-based breed group (P = .004), haemoabdomen (P < .001) and neutrophil count (P = .025) predicted malignancy, and genotype-based breed group (P < .001) and haemoabdomen (P < .001) predicted haemangiosarcoma. Genotype-based breed group and occurrence of haemoabdomen may have predictive value to diagnose malignant splenic masses and more specifically haemangiosarcoma. The effect of genotype-based breed grouping was a superior predictor of the diagnosis of a canine splenic mass lesion compared with all phenotype-based groupings tested.

Neutrophilia is associated with a poorer clinical outcome in dogs with chronic hepatitis

BACKGROUND

Liver disease is a common cause of morbidity and mortality in dogs. Currently, it is challenging to prognosticate in these cases. The aim of this study was to evaluate the utility of the haematological variables in dogs with chronic hepatitis.

METHODS

Dogs with chronic hepatitis confirmed on histopathology had presenting haematological values retrospectively obtained and evaluated against survival time. Eighty-two dogs met the inclusion criteria and their data analysed.

RESULTS

Neutrophilic patients, with a count greater than 12×10⁹/l, controlled for sex and age, had a shorter survival time (P≤0.01). In dogs, neutrophilia at presentation predicted a poor outcome, whereas the other haematological parameters were not prognostically informative. When the dogs were split into even quarters on the basis of their neutrophil count, those within the higher quartiles had poorer survival times. Neutrophilia was associated with a poorer survival time in comparison to those patients with a lower count.

CONCLUSION

The relationship between neutrophils, inflammation and clinical outcome is deserving of future study in dogs with chronic hepatitis.

Ultrasound is a poor predictor of early or overt liver or spleen metastasis in dogs with high-risk mast cell tumours

Conflicting evidence exists regarding the importance of routine abdominal ultrasound (US) with hepatic and splenic fine needle aspiration (FNA) cytology during staging of canine mast cell tumours (MCT). The objective of this study was to correlate ultrasonographic and cytologic findings in dogs with strictly defined high-risk MCTs and to determine the influence on outcome. Our hypothesis was that US poorly predicts visceral metastasis in high-risk MCTs and that early metastasis is associated with improved outcome when compared to overt metastasis. US of liver and spleen correlated to cytologic results, categorized as no metastasis, early metastasis or overt metastasis. Of 82 dogs prospectively enrolled, 18% had early visceral metastasis and 7% had overt metastasis on cytology; 67% with visceral metastasis had regional LN metastasis. US was a poor predictor of metastasis with sensitivity, specificity, positive predictive value and negative predictive value for the spleen of 67%, 68%, 21% and 94%, respectively and for the liver of 29%, 93%, 56% and 82%, respectively. Median time to progression (TTP) for dogs with no metastasis, early metastasis and overt metastasis was not reached, 305 and 69 days, respectively (P < .001). Median survival time (MST) for the 3 groups were not reached, 322 and 81 days, respectively (P < .001). High Patnaik or Kiupel grade, early metastasis, overt metastasis and adequate local control were significantly associated with outcome. Early visceral metastasis was associated with poorer outcome compared to dogs without metastasis, however, a subset of dogs experienced long-term control.

Evaluation of leukocyte counts and neutrophil-to-lymphocyte ratio as predictors of local recurrence of feline injection site sarcoma after curative intent surgery

Local recurrence (LR) is the major concern in the treatment of feline injection-site sarcoma (FISS). Pretreatment leukocyte counts and ratios have been reported as diagnostic and/or prognostic markers in human and canine oncology. The aim of this retrospective study was to explore the prognostic impact on LR and overall survival time (OST) of pretreatment neutrophil-to-lymphocyte ratio (NLR), white blood cell count (WBCC), neutrophil count (NC) and lymphocyte count (LC) in cats with surgically excised FISS. Eighty-two cats with histologically confirmed FISS at first presentation, without distant metastases, and with available pretreatment haematological analyses were retrospectively enrolled. The correlation of NLR, WBCC, NC, LC with tumour variables and patient variables was explored. NLR was correlated with tumour size (P = .004), histological pattern of tumour growth (P = .024) and histotype (P = .029), while WBCC and NC were associated with ulceration (P = .007, P = .011) and pattern of growth (P = .028, P = .004). No significant relationships emerged between LC and any of the considered variables. The impact of NLR, WBCC, NC, LC on LR and OST was then estimated in univariate and multivariate analysis. In univariate analysis, NLR, WBCC and NC were significant prognostic factors for both LR and OST. NLR, WBCC and NC remained prognostic in multivariate analysis for LR but not for OST. When NLR, WBCC and NC were jointly analysed, WBCC was the marker with the greater impact on LR. Preoperative NLR, WBCC and NC may aid in identifying cats at higher risk of LR.

Patient and tumour factors influencing canine mast cell tumour histological grade and mitotic index

The aim of this study was to identify patient and tumour factors most frequently associated with high histological grades of canine mast cell tumours (MCTs). Search criteria in a shared database of multiple Animal Referral Hospital locations within Australia generated 400 canine MCTs in 286 patients. Patient and tumour data were extrapolated and the association between a tumour being histologically high grade and patient and tumour factors, including: patient breed, patient gender and neuter status, patient age at MCT excision, tumour location and tumour size was assessed using univariate analysis. The study consisted of 90 (21.9%) tumours meeting histological high-grade criteria. Shar peis were the most likely breed to have high grade MCTs, whereas the Pug and the Golden Retriever were the least likely breeds to develop high-grade MCTs. No significant difference in risks could be established between the age at which the tumour was excised, or the gender and neuter status of patients. MCTs of the inguinal region were the most likely single location to be high grade. Tumour size did not influence the likelihood of a tumour being high grade or low grade. The results of this study suggest that patient and tumour factors may play a role in the histological grades of canine MCTs.

Clinicopathological findings in 41 dogs (2008-2018) naturally infected with Ehrlichia ewingii

Background

Ehrlichia ewingii is the most seroprevalent Ehrlichia‐infecting dogs in the southern and mid‐western United States. Fever, lameness, and polyarthritis are commonly reported findings in dogs naturally infected with E. ewingii.

Objectives

To evaluate clinicopathologic findings in a population of dogs naturally infected with E. ewingii.

Animals

Forty‐one dogs PCR positive for E. ewingii and PCR negative for other targeted vector‐borne organisms.

Methods

Retrospective study. Clinical and clinicopathologic data including physical examination findings, CBC, serum biochemistry, urinalysis (UA), symmetric dimethylarginine (SDMA), and vector‐borne disease diagnostic results were reviewed.

Results

Frequent clinical diagnoses other than ehrlichiosis (28/41; 68.3%) were renal disease (7/41; 17.1%) and immune‐mediated hemolytic anemia (IMHA) (6/41; 14.6%). The most frequent physical examination finding was joint pain (14/41; 34.1%). Prominent hematologic and biochemical abnormalities included abnormal lymphocyte counts (22/36; 61.1%); neutrophilia (21/37; 56.8%); increased alkaline phosphatase (20/35; 57.1%) and alanine transaminase (14/35; 40%) activities; and increased SDMA concentration (11/34; 32.4%). Urinalysis abnormalities included proteinuria (20/27; 74%), most with inactive sediments (16/20; 80%). Dogs were seroreactive by Ehrlichia canis immunofluorescence assay (IFA; 17/39; 43.6%) and Ehrlichia ELISA (34/41; 82.9%). Seroreactivity by IFA for other vector‐borne pathogens included Bartonella (1/39; 2.6%), Rickettsia rickettsii (spotted‐fever group rickettsiae) (12/39; 30.8%), and Borrelia burgdorferi by ELISA (1/41; 2.4%).

Conclusions and Clinical Importance

Renal disease, IMHA, proteinuria, neutrophilia, abnormal lymphocytes, and increased liver enzyme activities were common in this group of E. ewingii‐infected dogs. Studies are needed to determine if E. ewingii contributes to comorbidities or is a precipitating factor in clinical syndromes in persistently infected dogs.

Utility and Prognostic Significance of Neutrophil-to-Lymphocyte Ratio in Dogs with Septic Peritonitis

Systemic inflammation is known to cause WBC abnormalities, specifically neutrophilia and lymphopenia. The neutrophil-to-lymphocyte ratio (NLR) is a simple and affordable biomarker that has been used in human clinical settings of sepsis but has not been investigated in veterinary species. We evaluated NLR in dogs with septic and nonseptic systemic inflammatory diseases and compared with a healthy dog population. An NLR ≥6 had an 84.39% sensitivity and 86.95% specificity to identify dogs with systemic inflammatory states; however, no ratio distinguished septic and nonseptic causes. The NLR was not associated with length of hospitalization, morbidity based on the acute patient physiologic laboratory evaluation scoring system, or mortality. The disassociation may be due to the retrospective nature of the study, including a restricted population size and acquisition of only a one-time blood sample. NLR is currently of limited use for diagnosis and prognosis in systemic inflammatory states in dogs, and larger, prospective studies are necessary to further evaluate NLR.

Oncolytic Sendai Virus Therapy of Canine Mast Cell Tumors (A Pilot Study)

Background: Canine mastocytomas (mast cell tumors) represent a common malignancy among many dog breeds. A typical treatment strategy for canine mastocytomas includes surgery, chemo- and radio-therapy, although in many cases the therapy fails and the disease progression resumes. New treatment approaches are needed. Aims: The goal of this pilot study was to examine safety and efficacy of oncolytic Sendai virus therapy administered to canine patients with cutaneous or subcutaneous mastocytomas. Materials and Methods: Six canine patients, with variable grades and stages of the disease, received virus therapy, either as a monotherapy, or in combination with surgery. The therapy included two or more virus applications administered weekly or biweekly. Each application of Sendai virus (107-108.6 EID50) consisted of multiple individual 0.01-0.1 ml injections delivered intratumorally, intradermally around a tumor, and under a tumor bed. Results: The treatment was well tolerated, with minor transitory side effects. Of the six dogs, two did not receive surgery or any other treatment besides the virus injections. The other four animals underwent radical or debulking surgeries, and in three of them the subsequent administration of Sendai virus completely cleared locally recurrent or/and remaining tumor masses. Five dogs demonstrated a complete response to the treatment, the animals remained disease free during the time of observation (2-3 years). One dog responded only partially to the virotherapy; its after-surgical recurrent tumor and some, but not all, metastases were cleared. This dog had the most advanced stage of the disease with multiple enlarged lymph nodes and cutaneous metastases. Conclusion: The results of the pilot study suggest that Sendai virus injections could be safe and efficient for the treatment of dogs affected by mastocytomas.They also suggest the need of further studies for finding optimal schemes and schedules for this kind of therapy.

Comparison of two melphalan protocols and evaluation of outcome and prognostic factors in multiple myeloma in dogs

Background

Multiple myeloma (MM) in dogs typically is treated with melphalan. A daily melphalan dosing schedule reportedly is well tolerated and associated with favorable outcome. Although anecdotally a pulse dose regimen has resulted in successful responses, little long‐term outcome and safety data is available regarding this dosing regimen for dogs with MM.

Hypothesis/objectives

(1) To compare outcome and adverse event profiles between pulse dose and daily dose melphalan schedules and (2) to report prognostic factors in dogs with MM treated with melphalan. We hypothesized that both protocols would have similar outcomes and tolerability.

Animals

Thirty‐eight client‐owned dogs diagnosed with MM receiving pulse dose (n = 17) or daily dose (n = 21) melphalan.

Methods

Retrospective cohort study assessing outcome and adverse events in dogs receiving either protocol. Risk factors were evaluated for their prognostic relevance.

Results

Both regimens were well tolerated and similarly effective, with an overall median survival time of 930 days. Renal disease and neutrophil‐to‐lymphocyte ratio (NLR) were negative prognostic factors, whereas hypercalcemia and osteolytic lesions were not prognostic factors in this study population.

Conclusions and Clinical Importance

Positive results support the use of either dosing regimen for the treatment of dogs with MM, and renal disease and NLR were negative prognostic factors. Prospective, controlled, and randomized studies are warranted to confirm these findings.