Clinical, Biochemical, and Hematological Characteristics, Disease Prevalence, and Prognosis of Dogs Presenting with Neutrophil Cytoplasmic Toxicity

Abstract

Neutrophil cytoplasmic toxicity is manifested as an abnormality in cell size or the cytoplasmic content upon examination of Romanowsky-stained blood smears, and is traditionally associated with infection and inflammation. The purpose of this retrospective study was to investigate the association of such changes with clinical and clinicopathologic characteristics, diseases, and prognoses in dogs. Dogs with neutrophil toxicity (n ϭ 248) were compared with negative controls (n ϭ 248). Statistical analyses included chi-square tests, independent t-tests, nonparametric Mann-Whitney tests, the chi-square trend test, and survival analysis. Dogs with neutrophil toxicity had a significantly higher prevalence of pale mucous membranes, tachycardia, fever, abdominal organomegaly, icterus, melena, and hematuria. Most mean hematologic variables were significantly different between groups. Dogs with neutrophil toxicity had a significantly (P Ͻ .05) higher prevalence of leukocytosis, leukopenia, neutrophilia, neutropenia, anemia, hyponatremia, hypokalemia, hypoproteinemia, hypoalbuminemia, and hypocalcemia. The prevalence of pyometra, parvovirus infection, acute renal failure, peritonitis, immune-mediated hemolytic anemia, disseminated intravascular coagulation, pancreatitis, septicemia, and neoplastic disorders was significantly higher among these dogs. Case fatality, hospitalization length, and treatment cost were significantly (P Ͻ .001) higher in dogs with neutrophil toxicity. Neutrophil toxicity severity was significantly (P Ͻ .0035) and positively associated with neutropenia, and negatively associated with leukocytosis and neutrophilia. A significant trend (P ϭ .05) toward increasing case fatality with an increase of neutrophil toxicity was observed. In the neutrophil toxicity group, dogs with leukopenia (Ͻ5.0 ϫ 10 3 /mm 3 ) had a significantly (P Ͻ .0001) higher case fatality compared to dogs with normal or high leukocyte counts. We conclude that evaluation of blood smears for neutrophil cytoplasmic toxicity provides useful clinical information and can serve as a good prognostic predictor.Key words: Canine; Döhle bodies; Hematology; Leukocytes; Toxic changes; Toxic neutrophils.T oxic neutrophils have abnormalities in cell size, nuclear shape and consistency, and cytoplasmic content, which are evident upon examination of Romanowskystained blood smears.1,2 Toxic changes occur in neutrophils during their development in the bone marrow, and are divided into 3 categories: nuclear, cytoplasmic, and giant neutrophils.1,2 The most commonly noted and important changes are the cytoplasmic ones, which include diffuse basophilia, granulation, foamy vacuolation, and the presence of Döhle bodies.1,2 Cytoplasmic basophilia appears as a bluish gray to dark-blue cytoplasm as opposed to the normal neutral cytoplasm of the cell, and results from RNA and ribosome retention in the neutrophil's cytoplasm during the maturation process.1,2 Toxic granulation refers to the presence of azurophilic granules in the neutrophil's cytoplasm, and is pres...

Association of Presence of Band Cells and Toxic Neutrophils with Systemic Inflammatory Response Syndrome and Outcome in Horses with Acute Disease

“…Findings are similar in dogs: hospitalized dogs with DLS were more likely to die or be euthanized in hospital than dogs without DLS . In dogs with toxic change, case fatality, duration of hospitalization, and treatment cost were increased, and in contrast to cats, case fatality rate increased significantly with increasing toxic grade . It should be noted that dogs have the largest neutrophil storage pool, thus the presence of a neutropenia or DLS is more significant than in other domestic mammals because it reflects an intense peripheral demand for neutrophils that has depleted a large storage pool.…”

“…6 In dogs with toxic change, case fatality, duration of hospitalization, and treatment cost were increased, and in contrast to cats, case fatality rate increased significantly with increasing toxic grade. 7 It should be noted that dogs have the largest neutrophil storage pool, thus the presence of a neutropenia or DLS is more significant than in other domestic mammals because it reflects an intense peripheral demand for neutrophils that has depleted a large storage pool. Because of the smaller size of their storage pools, neutropenia and DLS in cats and horses can develop with lesser inflammatory stimuli, and in horses in particular might not suggest the same severity of illness as in dogs.…”

“…This scale was modified from previously published tables grading toxic change in dogs and cats. 7,8 There is surprisingly little information in the veterinary literature on how to accurately and reliably grade toxic change. We modified the published grading scheme slightly by removing the category of "giant toxic neutrophils" because none were seen in our equine population, and by changing the definition for mild cytoplasmic vacuolation.…”

“…3,7,8 Neutrophil toxic change might be an early indicator of acute systemic illness and has been associated with disease severity, case fatality, hospitalization duration, and cost of treatment in dogs. 7 Similarly, in cats, the detection of toxic neutrophils is associated with disease severity, duration of hospitalization, and treatment cost. 8 To our knowledge, no studies have been conducted that have specifically evaluated band neutrophils and toxic change in adult equine emergency admissions and therefore, the value of the microscopic review of peripheral blood smear in adult horses is unknown.…”

Hindlimb lameness and gait abnormalities in bitches with pyometra

“…Neutrophil left shift and cytoplasmic toxicity are common (Borresen 1980, Hardie 1995, Aroch and others 2005). Common serum biochemistry abnormalities include azotaemia, increased hepatobiliary enzymes activity, hypercholesterolaemia, hypoalbuminaemia and hyperglobulinaemia (Borresen 1980, Hagman 2004).…”