Effects of canine influenza infection and DA2PP vaccination on the development of platelet-associated immunoglobulins and platelet counts in dogs.

BACKGROUND: Immune thrombocytopenia (ITP) is commonly associated with platelet-associated immunoglobulins (PAIg). Demonstration of PAIg can help determine etiologies for thrombocytopenia. In humans, ITP and thrombocytopenia have been associated with various vaccinations and influenza infections, respectively. OBJECTIVES: We aimed to evaluate platelet counts and PAIg in research dogs with H3N2 and in research and client-owned dogs routinely vaccinated for distemper, adenovirus-2, parainfluenza, and parvovirus (DA2PP). The hypotheses were that H3N2 infection but not DA2PP vaccination would decrease platelet counts, and neither would result in the detection of PAIg. METHODS: Three pilot studies. Platelet counts and PAIg, measured by direct flow cytometry as %IgG, were evaluated in eight research Beagles following experimental infection with H3N2 (experiment 1), nine research Beagles vaccinated for DA2PP (experiment 2), and thirty client-owned dogs vaccinated for DA2PP (experiment 3). All animals were considered healthy at the start of the experiments. RESULTS: Transient, self-resolving decreases in platelet counts and increases in %IgG occurred following H3N2 infection, and one dog became thrombocytopenic and positive for PAIg. Following DA2PP vaccination, %IgG increased in research and client-owned dogs, but only one dog was considered positive for PAIg with a concurrent increase in platelet count. Mean PAIg increased from baseline in client-owned dogs following vaccination. CONCLUSIONS: Transient PAIg and thrombocytopenia can occur following H3N2 infection, while routine vaccination for DA2PP in this group of dogs was not associated with the development of thrombocytopenia or clinically relevant formation of PAIg.

A canine case of Ehrlichia canis infection without a history of being in an endemic area in Japan.

A mixed-breed, 8-year-old male dog developed neutropenia, thrombocytopenia, and hyperglobulinemia. Bone marrow hyperplasia and splenic plasmacytosis were cytologically observed. The dog had never been outside of Tokyo or Shizuoka Prefecture. Splenectomy was performed to confirm and remove the cause of splenic plasmacytosis. A histopathological diagnosis of splenic plasmacytoma was made; however, serum protein electrophoresis showed polyclonal gammopathy. Further screening was performed, and Ehrlichia canis infection was confirmed. The dog was treated with doxycycline for 5 weeks. After the antibiotic therapy, no relapse of neutropenia, thrombocytopenia, hyperglobulinemia, or positive polymerase chain reaction result of E. canis infection was observed for 3 years. Careful attention should be given to ehrlichiosis when exploring the cause of pancytopenia or hyperglobulinemia, regardless of the travel history.

Use of human intravenous immunoglobulin for the treatment of 12 dogs with newly diagnosed malignant disease and presumed secondary immune-mediated thrombocytopenia.

OBJECTIVES: To evaluate the safety and efficacy of human intravenous immunoglobulin in dogs with newly diagnosed malignancy and presumed secondary immune-mediated thrombocytopenia. MATERIALS AND METHODS: Twelve client-owned dogs with newly diagnosed malignant disease and presumed secondary immune-mediated thrombocytopenia were prospectively enrolled to receive a single infusion of human intravenous immunoglobulin at a dose of 0.5 to 1 mg/kg intravenous over 8 hours. A complete treatment response was defined as a platelet estimation of ≥40,000 platelets/µL within 24 hours and a partial response within 48 hours from the completion of human intravenous immunoglobulin infusion. No treatment response was defined as a platelet estimation remaining <40,000 platelets/µL over 48 hours from the completion of the human intravenous immunoglobulin infusion. This pilot study had a prospective, open-label, uncontrolled design. RESULTS: Out of the 12 enrolled dogs, seven completed the study. A complete treatment response to human intravenous immunoglobulin was identified in one lymphoma dog and a partial response was noted in another lymphoma dog. The remaining 10 dogs had no response to human intravenous immunoglobulin. No clinically relevant adverse reactions to human intravenous immunoglobulin occurred in any of the 12 initially enrolled dogs during the infusion and over a 3-month follow-up period for the seven surviving dogs. CLINICAL SIGNIFICANCE: The results of this study suggest that the use of human intravenous immunoglobulin in dogs with newly diagnosed malignant disease and presumed secondary immune-mediated thrombocytopenia appears safe, but not effective for the treatment of thrombocytopenia. Larger multi-centre, prospective, double-blinded, placebo-controlled, outcome-based, malignancy-specific studies are needed to further evaluate these preliminary findings.

Potent immunogenicity and neutralization of recombinant adeno-associated virus expressing the glycoprotein of severe fever with thrombocytopenia virus.

Severe fever with thrombocytopenia syndrome (SFTS) is an infectious disease caused by a tick-borne virus called severe fever with thrombocytopenia syndrome virus (SFTSV). In recent years, human infections through contact with ticks and through contact with the bodily fluids of infected dogs and cats have been reported; however, no vaccine is currently available. SFTSV has two glycoproteins (Gn and Gc) on its envelope, which are vaccine-target antigens involved in immunogenicity. In the present study, we constructed novel SFTS vaccine candidates using an adeno-associated virus (AAV) vector to transport the SFTSV glycoprotein genome. AAV vectors are widely used in gene therapy and their safety has been confirmed in clinical trials. Recently, AAV vectors have been used to develop influenza and SARS-CoV-2 vaccines. Two types of vaccines (AAV9-SFTSV Gn and AAV9-SFTSV Gc) carrying SFTSV Gn and Gc genes were produced. The expression of Gn and Gc proteins in HEK293T cells was confirmed by infection with vaccines. These vaccines were inoculated into mice, and the collected sera produced anti-SFTS antibodies. Furthermore, sera from AAV9-SFTSV Gn infected mice showed a potent neutralizing ability, similar to previously reported SFTS vaccine candidates that protected animals from SFTSV infection. These findings suggest that this vaccine is a promising candidate for a new SFTS vaccine.

Large granular lymphocyte lymphoma in 65 dogs (2005-2023).

Large granular lymphocyte lymphoma (LGLL) is a rare form of lymphoma in dogs. Limited information exists regarding presentation, treatment response, and outcome. The aim of this single-institute, retrospective study was to characterise clinical presentation, biologic behaviour, outcomes, and prognostic factors for dogs with LGLL. Cytologic review was also performed. Sixty-five dogs were included. The most common breed was the Labrador retriever (29.2%), and the most common presenting signs were lethargy (60.0%) and hyporexia (55.4%). The most common primary anatomic forms were hepatosplenic (32.8%) and gastrointestinal (20.7%). Twenty dogs (30.8%) had peripheral blood or bone marrow involvement. Thirty-two dogs were treated with maximum tolerated dose chemotherapy (MTDC) with a response documented in 74.1% of dogs. Dogs ≥7 years, and those with neutropenia or thrombocytopenia at diagnosis had the reduced likelihood of response to treatment. For dogs treated with MTDC median progression-free interval (PFI) was 17 days (range, 0-481), the median overall survival time (OST) 28 days (range, 3-421), and the 6-month and 1-year survival rates were 9.4% and 3.1%, respectively. On multivariable analysis, monocytosis and peripheral blood involvement were significantly associated with shorter PFI and OST. Long-term survival (≥100 days) was significantly associated with intermediate lymphocyte size on cytology. Dogs with LGLL have moderate response rates to chemotherapy but poor overall survival. Additional studies are needed to further evaluate prognostic factors and guide optimum treatment recommendations.

Doxorubicin and zoledronate treatment in a dog with hemophagocytic histiocytic sarcoma.

A 6-year-old castrated male greyhound dog was referred for hemophagocytic histiocytic sarcoma (HHS) diagnosed following splenectomy. Severe thrombocytopenia, mild hypoalbuminemia, mild hypocholesterolemia, and mild hyperbilirubinemia were present. Abdominal ultrasound findings were concerning for hepatic metastasis. Doxorubicin and zoledronate combination therapy was initiated. The dog improved clinically and its thrombocytopenia, hypoalbuminemia, and hyperbilirubinemia resolved. The dog appeared well for 147 d before tumor progression was noted. The dog was treated with lomustine as a final measure, with no response. The dog survived for 6 mo with chemotherapy. To the authors' knowledge, this is the first report of clinical benefit of chemotherapy for HHS. Key clinical message: Doxorubicin should be considered for treating canine HHS since this variant of the disease is historically refractory to lomustine. Further research regarding efficacy of doxorubicin and zoledronate should be pursued.

Traitement à la doxorubicine et au zolédronate chez un chien atteint de sarcome histiocytaire hémophagocytaire. Un lévrier mâle castré de 6 ans a été vu pour un sarcome histiocytaire hémophagocytaire (HHS) diagnostiqué à la suite d'une splénectomie. Une thrombopénie sévère, une hypoalbuminémie légère, une hypocholestérolémie légère et une hyperbilirubinémie légère étaient présentes. Les résultats de l'échographie abdominale étaient préoccupants quant aux métastases hépatiques. Un traitement associant doxorubicine et zolédronate a été instauré. Le chien s'est amélioré cliniquement et sa thrombocytopénie, son hypoalbuminémie et son hyperbilirubinémie ont disparu. Le chien semblait en bonne santé pendant 147 jours avant de constater une progression tumorale. Le chien a été traité avec de la lomustine comme mesure finale, sans réponse. Le chien a survécu 6 mois grâce à la chimiothérapie. À la connaissance des auteurs, il s'agit du premier rapport faisant état d'un bénéfice clinique de la chimiothérapie pour le HHS.Message clinique clé :La doxorubicine doit être envisagée pour traiter le HHS canin puisque cette variante de la maladie est historiquement réfractaire à la lomustine. Des recherches plus approfondies concernant l'efficacité de la doxorubicine et du zolédronate devraient être poursuivies.(Traduit par Dr Serge Messier).

Evaluation of factors influencing survival time in 77 dogs with lymphoma.

Background: Canine lymphoma is one of the most commonly reported hematopoietic tumors. Aim: A few retrospective studies have involved complex evaluations including diagnostic features and treatment protocols, but these studies infrequently demonstrate variable factors that affect survival time, and comparisons among chemotherapeutic protocols are limited. This study aimed to identify prognostic factors that can be simply detected in dogs with lymphoma, such as abnormalities in physical and hematologic findings, and treatment protocols. Methods: Clinical records of 77 dogs diagnosed with lymphoma were retrospectively reviewed. Results: The author newly identified leukocyte and platelet abnormalities as negative prognostic factors. Furthermore, this study suggests that decreased gastrointestinal toxicity and improvements of hematologic abnormalities, such as anemia, thrombocytopenia, and lymphocytosis or lymphoblasts, in peripheral blood during chemotherapy act as positive prognostic factors. Finally, strict adherence to therapeutic protocol and selecting multiple agents as rescue protocol are important to prolong survival time. Conclusion: This study identified indicators to be used as prognostic factors through survival analysis.

Causes of thrombocytopenia in dogs in the United Kingdom: A retrospective study of 762 cases.

BACKGROUND: Thrombocytopenia is a common laboratory abnormality in dogs, and numerous diseases have been associated with its development. Estimates for the sensitivity and specificity of the degree of reduction of platelet concentration for the diagnosis of primary immune-mediated thrombocytopenia (pITP) have not been reported. OBJECTIVES: To report the prevalence of different causes of thrombocytopenia in dogs in the United Kingdom and to investigate the utility of platelet concentration to differentiate causes of thrombocytopenia. METHODS: Medical records of 762 dogs with thrombocytopenia presented to seven referral hospitals from January 2017 to December 2018 were retrospectively reviewed. Cases were assigned into the following categories: pITP, infectious diseases, neoplasia, inflammatory/other immune-mediated disorders and miscellaneous causes. The prevalence of the different categories was estimated, and platelet concentrations were compared. Receiver-operating characteristic (ROC) curves were used to investigate the utility of platelet concentration to differentiate between causes of thrombocytopenia. RESULTS: The most common disease category associated with thrombocytopenia was neoplasia (27.3%), followed by miscellaneous causes (26.9%), pITP (18.8%), inflammatory/immune-mediated disorders (14.4%) and infectious diseases (12.6%). Dogs with pITP had significantly lower platelet concentrations (median 8 × 109 /L, range: 0-70 × 109 /L) than dogs in the other four categories. Platelet concentration was useful for distinguishing pITP from other causes of thrombocytopenia (area under ROC curve = 0.89, 95% confidence interval 0.87, 0.92), with a platelet concentration ≤12 × 109 /L being 60% sensitive and 90% specific. CONCLUSIONS: Severe thrombocytopenia was highly specific for a diagnosis of pITP, which was more prevalent in this UK population of thrombocytopenic dogs compared with previous epidemiological studies. Conversely, the proportion of dogs with infectious diseases was lower than in previous reports from other locations.

Contribution of Hemogram Plan in the Horse's Clinical Evaluation.

The interpretation of the blood count is essential to help the equine clinician in the diagnosis, prognosis, patient management, and control of equine diseases. Hematologic alterations often reflect the condition of the individual or an overall response to a pathological situation. A thorough clinical examination of the patient is essential to correctly interpret the hematological results. The most common abnormalities in the erythrogram are mainly anemia and polycythemia. The frequent causes of anemia in horses are acute and chronic blood loss, hemolytic anemia, and anemia caused by chronic disease. Evaluation of leukogram, including a total white cell count, a differential cell count, absolute numbers of specific leukocytes can help identify abnormalities that may suggest specific diseases such as a viral or bacterial infection, inflammatory disorders or even a neoplastic process. The platelet count is most often used to monitor or diagnose conditions that cause too much bleeding related with thrombocytopenia; it can be due to multiple mechanisms such as reduction of thrombopoiesis (myeloptisis, myelofibrosis, myeloproliferative disease, and idiopathic medullary aplasias or due to the effect of mielosuppresive drugs), increased peripheral destruction of platelets (immune mediated thrombocytopenia), consumption (dissemined intravascular coagulation) sequestration of the spleen and loss of platelets by idiopathic origin.

Hemophagocytic syndrome in a cat with immune-mediated hemolytic anemia.

A 10-year-old spayed female domestic short-haired cat presented with depression, anorexia, and tachypnea. A complete blood count revealed moderate regenerative anemia, severe leukopenia, and mild thrombocytopenia. Antibodies against feline immunodeficiency virus (FIV) were also detected. Abdominal radiography and ultrasonography revealed severe splenomegaly. Cytologic evaluation of the spleen revealed macrophagic infiltration with hemophagocytosis. Bone marrow aspiration revealed erythroid hyperplasia with no other abnormalities. A presumptive diagnosis of hemophagocytic syndrome secondary to immune-mediated hemolytic anemia was made based on a positive direct Coombs test result. Blood transfusion, prednisolone, and immunosuppressive treatments were performed; however, the blood abnormalities did not improve. The cat was then administered prednisolone and chlorambucil, followed by splenectomy. Leukopenia immediately recovered, and packed cell volume increased slightly. However, the blood abnormalities recurred, and the cat died. To the best of our knowledge, this is the first report of hemophagocytic syndrome secondary to immune-mediated disease in an FIV-positive cat.

Investigation of platelet measurands in dogs with hematologic neoplasia.

INTRODUCTION: Thrombocytopenia has been associated with some neoplastic processes, including hematologic neoplasia. There is no information regarding specific changes in platelet measurands in dogs with hematologic neoplasia compared with healthy dogs. The objectives of our study were to establish RIs, evaluate platelet measurands in dogs with hematologic neoplasia, and compare these measurands in patients with hematologic malignancies with or without thrombocytopenia. METHODS: This was a retrospective study. Platelet measurands were determined using the ADVIA 120 Hematology analyzer when a CBC was performed and included the platelet count, MPV, platelet distribution width (PDW), plateletcrit (PCT), mean platelet component (MPC), platelet component distribution width (PCDW), mean platelet mass (MPM), platelet mass distribution width (PMDW), and number of large platelets. Reference intervals were determined retrospectively using data from 129 healthy dogs. Patients with hematologic neoplasia (n = 50) were identified through retrospective evaluation of medical records from the Auburn University Veterinary Teaching Hospital and separated into thrombocytopenic (n = 20) and nonthrombocytopenic groups (n = 30). RESULTS: Platelet count and PCT were significantly higher in older healthy dogs compared with younger dogs. Significant differences were identified when comparing healthy dogs with those with hematologic neoplasia without thrombocytopenia for PDW, PCDW, PMDW, and the number of large platelets, indicating the presence of more heterogeneous platelets. Thrombocytopenic dogs with hematologic neoplasia had significantly decreased MPCs and increased MPVs, MPMs, and PCDWs compared with nonthrombocytopenic dogs with neoplasia. CONCLUSIONS: Dogs with hematologic neoplasia had more heterogeneous platelets, whereas thrombocytopenic patients with neoplasia had more activated platelets.

Amikacin prevents platelet aggregation in feline venous blood samples.

INTRODUCTION: Physiologically, feline platelets are more reactive and prone to aggregation, which interferes with platelet counts using automated counters and manual methods. The use of aminoglycoside amikacin in association with EDTA has proven to be efficient in preventing platelet aggregates in cases of pseudo thrombocytopenia (PTP) in people. OBJECTIVES: This study evaluated the efficacy of amikacin in preventing platelet aggregation in EDTA-containing feline blood samples and investigated the possible effects on hematologic measurands. MATERIALS AND METHODS: Blood samples (1.0 mL) collected from 100 healthy cats were stored in two EDTA tubes: 0.5 mL in a microtube containing 10 µL of 250 mg/mL amikacin (EDTA-AMK group) and 0.5 mL in a microtube containing only K2 EDTA 10% (EDTA group). A CBC was executed with an automated impedance blood analyzer, and a microscopic examination of the blood smears was performed. RESULTS: Platelet clumps were observed in 56% of samples from the EDTA group and 5% of samples from the EDTA-AMK group. Platelet counts (PLT), plateletcrit (PCT), and WBC counts were significantly higher (P < .001) in the EDTA-AMK group compared withi the EDTA group. CONCLUSIONS: Amikacin prevents platelet aggregation in feline venous blood samples and does not cause clinically relevant changes in other hematologic measurands. To our knowledge, this is the first report showing the use of amikacin in preventing platelet aggregation in feline blood samples. Based on this study, amikacin could be added to EDTA collection tubes for complete blood counts in cats.

Increased risk of select glucocorticoid adverse events in dogs of higher body weight.

There are limited data on glucocorticoid treatment in dogs. The purpose of this study was to investigate whether dogs of higher body weight experienced more adverse events when receiving glucocorticoid therapy. Data pertaining to glucocorticoid therapy was abstracted from the records of 61 dogs that were prescribed glucocorticoids for treatment of immune-mediated thrombocytopenia or hemolytic anemia from 2014 to 2019. The odds of developing muscle atrophy and polyphagia during therapy were increased by 30% for each 5 kg of additional body weight. Almost half of the dogs (44.3%) fluctuated > 15% from baseline weight during therapy. Dogs whose body condition scored as above ideal were at increased risk (odds ratio = 4.2) for being diagnosed with urinary tract infection. Our findings suggest that standard linear glucocorticoid dosing may place higher body weight dogs at increased risk of developing adverse events. Accelerated glucocorticoid tapering and/or alternative dosing schemes in dogs with higher body weights may be prudent in efforts to improve tolerance and client compliance.

Risque accru d'événements indésirables liés aux glucocorticoïdes chez les chiens de poids corporel plus élevé. Les données sur le traitement par glucocorticoïdes chez le chien sont limitées. Le but de cette étude était de déterminer si les chiens de poids corporel plus élevé présentaient plus d'événements indésirables lorsqu'ils recevaient un traitement par glucocorticoïdes. Les données relatives au traitement par glucocorticoïdes ont été extraites des dossiers de 61 chiens auxquels des glucocorticoïdes ont été prescrits pour le traitement d'une thrombocytopénie à médiation immunitaire ou d'anémie hémolytique de 2014 à 2019. Les risques de développer une atrophie musculaire et une polyphagie pendant le traitement ont augmenté de 30 % pour chaque 5 kg de poids corporel supplémentaire. Près de la moitié des chiens (44,3 %) ont fluctué > 15 % par rapport au poids de base pendant le traitement. Les chiens dont l'état corporel était supérieur à l'idéal présentaient un risque accru (rapport de cotes = 4,2) de recevoir un diagnostic d'infection des voies urinaires. Nos résultats suggèrent que le dosage linéaire standard de glucocorticoïdes peut exposer les chiens de poids corporel plus élevé à un risque accru de développer des événements indésirables. Une diminution accélérée des glucocorticoïdes et/ou des schémas posologiques alternatifs chez les chiens ayant un poids corporel plus élevé peuvent être avisés dans les efforts visant à améliorer la tolérance et l'observance du client.(Traduit par Dr Serge Messier).

Anaplasma phagocytophilum in domestic cats from Germany, Austria and Switzerland and clinical/laboratory findings in 18 PCR-positive cats (2008-2020).

OBJECTIVES: Anaplasma phagocytophilum is considered the most significant rickettsial pathogen affecting cats. The organism is transmitted by ticks of the species Ixodes ricinus in Central Europe and can cause granulocytic anaplasmosis in pets, wildlife and humans. The aims of this study were to assess the frequency of positive test results for A phagocytophilum in cats in Germany, Austria and Switzerland, as well as to evaluate clinical and laboratory findings in cats with positive PCR results. METHODS: This study included the results of direct (PCR) and indirect detection methods (immunofluorescence antibody tests [IFAT]) requested by veterinarians in Germany, Austria and Switzerland between 2008 and 2020 from the LABOKLIN laboratory (Bad Kissingen, Germany). The veterinarians treating the PCR-positive cats were contacted by telephone to enquire about their clinical signs, laboratory findings, management and outcomes. RESULTS: In total, 244/1636 cats (15%) tested positive by direct (PCR: n = 27/725 [4%]) and/or indirect detection methods (IFAT: n = 221/956 [23%]). In 18/26 cats with PCR results positive for A phagocytophilum, additional information about clinical signs, laboratory findings, treatment and outcome was obtained. Of these 18 cats, five had comorbidities independent of their infection with A phagocytophilum. The most common clinical signs in PCR-positive cats (total/without comorbidities) were lethargy (83%/92%), fever (83%/85%) and thrombocytopenia (61%/62%). Overall, more than half (57%) of the cats with and without comorbidities recovered clinically. CONCLUSIONS AND RELEVANCE: Infections with A phagocytophilum should be considered as differential diagnoses in cats with tick infestation, lethargy, fever and thrombocytopenia. The clinical signs and laboratory findings are consistent with published case reports in cats. Ectoparasite prophylaxis in cats is recommended throughout the entire year.

Transient thrombocytopenia in a cat following G-CSF treatment.

A 4-year-old, castrated male, Russian blue cat with idiopathic epilepsy was diagnosed with neutropenia. The neutropenia was classified as idiopathic after blood tests and abdominal imaging did not reveal an infectious, inflammatory or neoplastic aetiology. As a treatment trial for idiopathic neutropenia, the cat was administered granulocyte colony-stimulating factor by subcutaneous injection once daily for 3 days. Two weeks after completion of granulocyte colony-stimulating factor therapy, the cat developed severe thrombocytopenia, with the granulocyte colony-stimulating factor therapy considered to be the most likely cause. No treatment was initiated, and the thrombocytopenia had resolved spontaneously by 2 weeks after diagnosis. This is the first reported case of transient severe thrombocytopenia in a cat following granulocyte colony-stimulating factor treatment.

Presumptive hemophagocytic syndrome associated with immune-mediated anemia in two Miniature Dachshunds.

This report describes the cases of two Miniature Dachshunds who were suspected to have immune-mediated hemolytic anemia (IMHA) and were treated with immunosuppressive therapy. However, progression of anemia, increases in C-reactive protein (CRP) and total-bilirubin (T-Bil) levels, splenomegaly, transition to nonregenerative anemia, and thrombocytopenia occurred after the treatment. Splenectomy and bone-marrow aspirations were performed subsequently. Both dogs were diagnosed with hemophagocytic syndrome (HPS) associated with IMHA. Unfortunately, they died 9 and 6 days later. These findings indicate that some cases of refractory IMHA have the pathogenicity of HPS. HPS should be included as a differential diagnosis of refractory IMHA concurrent with thrombocytopenia. Continuously elevated CRP and T-Bil levels may be helpful indicators in the detection of HPS associated with IMHA.

Retrospective evaluation of thrombocytopenia and tumor stage as prognostic indicators in dogs with splenic hemangiosarcoma.

OBJECTIVE: To identify physical examination and perioperative CBC variables in dogs with splenic hemangiosarcoma (HSA) that could aid in predicting progression-free interval (PFI) and overall survival time (OST) in affected dogs. ANIMALS: 70 client-owned dogs with splenic HSA treated with splenectomy and chemotherapy between September 2004 and October 2016. PROCEDURES: A retrospective search of the University of Minnesota Veterinary Medical Center medical records database was performed to identify dogs with splenic HSA treated with splenectomy and with evidence in the medical records of intent to treat with chemotherapy. Data collection included dog signalment and body surface area, results from CBCs performed within 6 days before to 2 days after splenectomy, whether dogs had hemoabdomen or received transfusions, and tumor stage. Hematocrit, WBC count, and platelet count were treated as categorical variables (divided into terciles: above, within, or below reference limits) because of variation among reference intervals for the numerous analyzers used. Associations between variables and PFI or OST were investigated with Cox regression analyses, and hazard ratios (HRs) for a shorter PFI or OST were reported. Population Pearson correlation coefficient (ρ) analysis was performed to identify potential associations between variables of interest. RESULTS: Stage 3 HSA was identified as a negative prognostic indicator of PFI (HR, 6.6) and OST (HR, 4.5). Perioperative thrombocytopenia was similarly associated with shorter PFI (HR, 2.2) and OST (HR, 2.0). Results for Hct correlated (ρ = 0.58) with those for platelet count, and although our findings did not indicate a notable association between anemia and shorter PFI, such could not be ruled out. CONCLUSIONS AND CLINICAL RELEVANCE: The prognostic value of thrombocytopenia warrants further substantiation to understand causal and mechanistic connections, and the presence of thrombocytopenia ultimately may prove valuable in guiding treatment recommendations for dogs with splenic HSA.

Neutropenia in dogs receiving vincristine for treatment of presumptive immune-mediated thrombocytopenia.

BACKGROUND: Neutropenia is an adverse effect of vincristine when used in multidrug chemotherapy protocols. OBJECTIVE: To determine the incidence of neutropenia, identify potential risk factors for neutropenia, and determine the effect of neutropenia on outcome, in dogs receiving vincristine for treatment of immune-mediated thrombocytopenia (ITP). ANIMALS: One hundred twenty-seven client-owned dogs presumptively diagnosed with ITP. METHODS: In this retrospective cohort study, medical records were reviewed to identify dogs presumptively diagnosed with ITP, and treated with vincristine, over a 15-year period. Logistic regression was used to identify risk factors for the development of neutropenia in dogs receiving vincristine. Time to platelet count ≥40 000 platelets/µL, survival, and duration of hospitalization were compared between neutropenic and non-neutropenic dogs. RESULTS: Vincristine was administered to 127 dogs with presumptive ITP; 19 became neutropenic. Administration of cyclosporine was significantly (P < .001) associated with the development of neutropenia (odds ratio: 12.97, 95% confidence interval: 4.17, 40.35). There was no difference in median time to ≥40 000 platelets/µL between neutropenic dogs (4 days; range, 1-14 days) and non-neutropenic dogs (3 days; range, 0-48 days). Percentage survival to discharge was 95% in both groups, but median duration of hospitalization was significantly longer in neutropenic dogs (6 days; range, 3-22 days) compared to non-neutropenic dogs (4 days; range, 2-15 days). CONCLUSIONS AND CLINICAL IMPORTANCE: Cyclosporine administration was associated with the development of neutropenia in dogs receiving vincristine, which might be related to effects on metabolism of vincristine. Neutrophil counts should be monitored in dogs receiving vincristine treatment for ITP, particularly if administered in conjunction with cyclosporine.

Immune-mediated haemolytic anaemia and thrombocytopenia in 25 adult equids: 1997-2016.

BACKGROUND: Information concerning clinical presentation, conditions associated with immune-mediated haemolytic anaemia (IMHA) and thrombocytopenia (IMTP) and outcome in equids is lacking. Previous case reports suggest that immune-mediated disease and neoplasia are associated. OBJECTIVES: Characterise the clinical presentation, clinicopathologic data, underlying conditions, treatment and outcome of IMHA and IMTP cases in equids. We hypothesise that IMHA with concurrent thrombocytopenia occurs more often than IMHA or IMTP alone, and that neoplasia is commonly associated with these immune diseases and cases frequently have a poor prognosis. STUDY DESIGN: Retrospective case-control study. METHODS: Medical records were reviewed from 1997 to 2016. Twenty-five equids were diagnosed with IMHA, IMTP or IMHA with thrombocytopenia by Coombs test or flow cytometry. Controls were equids presented for nonimmune-mediated disease immediately prior to and after study animals. Fisher's exact test was used to compare between groups for categorical variables (P < .05). Results reported as odds ratios (OR) and 95% confidence intervals (CI). Unpaired t test and Mann-Whitney test were used to compare between groups for continuous variables (P < .05). RESULTS: Neoplasia incidence was significantly higher in the study population (28%) versus controls (8%) (P = .04). Equids with primary disease were more likely to survive to discharge than equids with secondary disease (8/9 vs 7/16; P = .03; OR = 13.3; 95% CI: 1.3-134.7). Survivors had a significantly lower blood urea nitrogen (BUN) than those that died or were subjected to euthanasia (survivors, 6.1 ± 2.5 mmol/L vs nonsurvivors, 9.9 ± 3.1 mmol/L P = .003). The odds of short-term mortality were higher in horses presenting with increased BUN (OR = 19.5; 95% CI, 1.8-214.1; P = .009). MAIN LIMITATIONS: Retrospective nature of the study, small case numbers and limited long-term follow-up. CONCLUSIONS: Primary IMHA/IMTP cases have a reasonable prognosis and warrant treatment. Secondary cases have a poor prognosis, and are frequently associated with cancer. BUN may have utility as a prognostic indicator for IMHA/IMTP cases.

Carboplatin-induced myelosuppression as related to body weight in dogs.

Smaller dogs are known to have an increased risk of chemotherapy-induced myelosuppression for doxorubicin, mitoxantrone and melphalan. This retrospective study aimed to determine if dogs <15 kg and <10 kg experienced greater degrees of myelosuppression following treatment with carboplatin chemotherapy compared with dogs ≥15 kg. One hundred and one dogs treated with carboplatin for a variety of malignancies were retrospectively analysed. Eight dogs (61%) weighing <10 kg, three (38%) weighing 10 kg to <15 kg and 14 (17%) weighing ≥15 kg experienced a grade 3 or 4 neutropenia. Five dogs (38%) weighing <10 kg, two (25%) weighing 10 kg to <15 kg and 13 (16%) weighing ≥15 kg experienced a grade 3 or 4 thrombocytopenia. Dogs <10 kg were significantly more likely to develop a grade 3 or 4 neutropenia following carboplatin than dogs ≥10 kg (3.5 RR; 95% CI, 1.9-6.3; P < .001). Dogs <15 kg were also significantly more likely to develop a grade 3 or 4 neutropenia than dogs ≥15 kg (3 RR; 95% CI, 1.6-5.6; P = .004). Dogs <10 kg were significantly more likely to develop a grade 3 or 4 thrombocytopenia than those dogs ≥10 kg (2.5 RR; 95% CI, 1.1-5.6; P = .006). Hospitalization was significantly more likely for dogs <10 kg vs ≥10 kg (P = .014) as well as for dogs <15 kg vs ≥15 kg (P = .039). This study demonstrates an increased risk of carboplatin-induced myelosuppression in dogs <15 kg, and particularly those <10 kg. This information should be considered by clinicians when making decisions regarding the initial carboplatin dose for smaller canine patients, especially those <15 kg.