Heinz body haemolytic anaemia in a dog secondary to ingestion of a zinc toy: a case report

A 6-year-old Labrador retriever was referred for investigation of severe lethargy and suspected immune-mediated haemolytic anaemia. Clinical examination revealed pale mucous membranes and jaundice. Haematology demonstrated large numbers of Heinz bodies and a marked anaemia, which was strongly regenerative. Serum zinc concentrations were markedly elevated. Analysis of a metal toy vomited by the dog 3 days prior to presentation revealed it to be composed of almost pure zinc. A diagnosis of haemolytic anaemia secondary to acute zinc toxicity was made and supportive therapy instigated. There was a subsequent decrease in numbers of Heinz bodies and a rise in the haematocrit, and the dog made an uneventful recovery. Acute zinc toxicity resulting in haemolytic anaemia is rarely observed, and this case was also unusual in that the main clinicopathological finding was the presence of numerous Heinz bodies without other evidence of oxidative damage to red blood cells.     

Experimental onion-induced hemolytic anemia in dogs

Within one day following a single oral dose of dehydrated onions, dogs were found to have large numbers of Heinz bodies within erythrocytes. The percentage of erythrocytes that contained Heinz bodies increased slightly to a maximum on day 3 and then declined. The turbidity index increased more gradually with a maximal value on day 4. Erythrocytes with hemoglobin contracted to one side of the cell (eccentrocytes) also appeared after onion feeding. Eccentrocytes are believed to result from a direct injury to the erythrocyte membrane. As with Heinz body-containing cells, the percentages of eccentrocytes present declined as anemia developed. The packed cell volume began to decrease one day after onion administration. A mean decrease of 19 percentage points was reached by day 5. The most anemic dogs had evidence of intravascular hemolysis. Reticulocytosis was first observed five days after onion administration. A slight increase in methemoglobin content was measured four hours after onion administration. No significant changes in erythrocyte reduced glutathione concentration were measured. Transient neutrophilia occurred concomitant with the peak reticulocyte response.     

Pathomorphological changes in calf erythrocytes during phenylhydrazine-induced acute hemolytic anaemia.

In acute hemolytic anaemia of calves induced with phenylhydrazine-hydrochloride, accentuated degenerative changes in circulating erythrocytes occurred on the 5th d post-injection. Marked anisocytosis and poikilocytosis were observed. Crenated cells, acanthocytes (star-shaped cells), dacrocytes (tear drop cells), bite cells, and schistocytes predominated. Heinz bodies were the cytoplasmic hallmark of hemolytic anaemia. The regenerative nature of anaemia was evidenced by early appearance of reticulocytes in peripheral blood.     

Pathology of 2-alkyl and 2-hydroxy naphthoquinone toxicity in rats

Abstract Extract The oral administration of 2-methyl-1, 4-naphthoquinone (menadione) to rats caused oxidative destruction of the erythrocyte. Heinz body formation occurred in erythrocytes, lowered PCVs and haemoglobin Occurred in blood, with splenic and hepatic erythroclasis, and iron conservation in the spleen, liver and kidney. These effects diminished when increasingly large alkyl substitutions of the methyl group of thi naphthoquinone were made. No effect was caused by the 2-decyl derivative.     

Pathology of 2-alkyl and 2-hydroxy naphthoquinone toxicity in rats

Extract

The oral administration of 2-methyl-1, 4-naphthoquinone (menadione) to rats caused oxidative destruction of the erythrocyte. Heinz body formation occurred in erythrocytes, lowered PCVs and haemoglobin Occurred in blood, with splenic and hepatic erythroclasis, and iron conservation in the spleen, liver and kidney. These effects diminished when increasingly large alkyl substitutions of the methyl group of thi naphthoquinone were made. No effect was caused by the 2-decyl derivative.     

Scanning electron microscopy of Heinz bodies in feline erythrocytes.

Whole blood and partially lysed blood films from 5 cats having 20 to 91% of the erythrocytes containing Heinz bodies were examined, using the light microscope and the scanning electron microscope. Heinz bodies were detected in the intact erythrocytes from 3 of the cats as abruptly elevated and distinctly demarcated protuberances in various shapes, sizes, and locations. The Heinz bodies were located just beneath the cell membrane either centrally or near the cell margin and varied in their projectional magnitude. Brilliant cresyl blue staining of blood of these 3 cats revealed prominent Heinz bodies within, and projecting from, the erythrocytes. In contrast, Heinz bodies were not identified on scanning electron microscopy of intact erythrocytes of the remaining 2 cats even though Heinz bodies were found on their blood films stained with brilliant cresyl blue. Scanning electron microscopy of partially lysed blood smears of all 5 cats revealed Heinz bodies of various sizes in the erythrocyte ghosts. Furthermore, blood smears from the 3 cats having distinct Heinz bodies in intact erythrocytes revealed small dense intracellular granules distributed singly or coalesced in small clumps. Further aggregation of these clumps was assumed to result in the formation of a single large Heinz body. The 3-dimensional nature of Heinz bodies was clearly apparent in lysed blood smears.     

Relation of endogenous Heinz bodies to disease and anemia in cats: 120 cases (1978-1987)

Disease diagnosis, age, sex, and selected hematologic variables were evaluated retrospectively in a population of feline patients with high number of circulating Heinz bodies. By comparing these cats with a control population and results of additional hematologic investigation on a subsample of the cats, we tested the hypotheses that endogenous Heinz body formation is increased in specific disease states and that endogenous Heinz bodies may contribute to anemia. There was strong correlation between diabetes mellitus, hyperthyroidism, and lymphoma and Heinz body formation. Diabetic cats, in particular, consistently had marked Heinz body formation. These diseases together accounted for nearly 40% of cats with Heinz body formation, but for less than 12% of cats of the control group. The PCV of cats with Heinz bodies (29.77 +/- 9.32%) was significantly (P less than 0.001) lower than that of control cats (35.33 +/- 8.08%). Polychromasia and punctate reticulocyte number were slightly increased in cats with Heinz body formation and correlated significantly (P less than 0.001) with PCV. A subsample of 13 of the cats had significant (P less than 0.006) inverse correlation between Heinz body percentage and erythrocyte reduced glutathione (GSH) concentration. Mean GSH concentration was significantly lower in cats with Heinz bodies, compared with that in a random cat population (5.28 +/- 1.67 mumol/g of hemoglobin vs 7.06 +/- 2.10 mumol/g of hemoglobin), in which GSH values followed normal distribution. Cats with Heinz body formation were older, and were more likely to be spayed.     

Erythrocyte pathology and mechanisms of Heinz body-mediated hemolysis in cats

Despite the frequency of both oxidant drug-induced and spontaneous Heinz body formation in cats, the cellular and biochemical mechanisms by which Heinz bodies result in red blood cell (RBC) destruction and hemolytic anemia in this species remain unknown. Feline spleens are non-sinusoidal and inefficient at removing Heinz body-containing RBC from the circulation; therefore, alternative mechanisms must be involved in accelerated RBC destruction. Propylene glycol (PG) ingestion causes dose-dependent Heinz body formation and decreased RBC survival in cats. We investigated several aspects of Heinz body-containing RBC from three cats ingesting diets that provided 8.0 g PG/kg body weight for up to 3 weeks, in order to characterize cellular lesions that are associated with the presence of Heinz bodies and that might contribute to chronic, accelerated RBC destruction, as well as to gain insight into the mechanism by which PG induces Heinz body formation. Erythrocytes with PG-induced Heinz bodies had decreased levels of reduced glutathione and adenosine triphosphate and reduced deformability. There was no change in hemoglobin isoelectric focusing or membrane lipid peroxidation. Electrophoretic patterns of Heinz body-containing RBC membranes were significantly altered, and membrane surface charge distribution was disturbed. Progressively protruding Heinz bodies suggested that extrusion of Heinz bodies may be a means of cell healing and/or destruction in the absence of splenic pitting. When compared to results obtained using RBC from cats treated with the oxidant drug phenylhydrazine, significant differences were noted in packed cell volume, turbidity index, membrane heme, and morphologic appearance of Heinz bodies. Our results indicate that multiple cellular abnormalities develop in RBC with PG-induced Heinz bodies that do not cause acute hemolysis but that may shorten RBC survival. Propylene glycol-induced Heinz bodies provide an ideal model for studying the chronic effects of Heinz bodies on RBC structure and function and may be useful in understanding the mechanisms of formation and the consequences of endogenous Heinz bodies in cats.     

Morphological lesions in red blood cells from herring gulls and Atlantic puffins ingesting Prudhoe Bay crude oil

Red blood cells from nestling herring gulls and Atlantic puffins that had ingested 10 ml or more of a Prudhoe Bay crude oil/kg body weight/day for four to five days were examined by light and electron microscopy. In stained smears, red blood cells from oil-dosed birds were characterized by anisocytosis, poikilocytosis, reticulocytosis, and Heinz body formation. In transmission electron micrographs, affected cells had intracytoplasmic and intranuclear Heinz bodies, a variety of abnormal cytoplasmic vesicles, degenerate mitochondria, absence of circumferential microtubules, abnormal shape, and crenulation of the plasma membrane. The latter two cell surface anomalies were evident in scanning electron micrographs. Identical lesions were present in red cells from gulls injected with phenylhydrazine. Reticulocytosis was the only change evident in blood from gulls made anemic by hemorrhage. These observations support the hypothesis that the toxicity of ingested Prudhoe Bay oil to red cells was exerted by oxidant chemical compounds.     

Effect of diet on Heinz body formation in kittens

Heinz body formation was examined in kittens, in response to consumption of a variety of diets. A commercial salmon-based diet containing 16.5 mg of nitrite, 39 mg of histamine, and 210,000 IU of vitamin A/kg of diet (dry-matter basis) was found to induce Heinz body formation. Purified experimental diets--containing nitrite up to 405 mg/kg; histamine, 50 mg/kg; histamine 50 mg/kg plus nitrite, 45 mg/kg; or vitamin A, 250,000 IU/kg--failed to induce Heinz body formation. The effect of propylene glycol (PG) on Heinz body formation was examined by giving groups of 6 kittens purified diets containing 5 or 10% PG for 12 weeks. Two additional kittens were fed a commercial soft-moist diet containing PG for 12 weeks. All kittens fed PG developed Heinz bodies, with peak values for erythrocytes containing Heinz bodies being: 28% for kittens of the 10% PG group; 20% for kittens of the 5% PG group; and 36% for kittens of the soft-moist diet group. Kittens did not develop anemia or methemoglobinemia. Heinz body percentage required 6 to 8 weeks to decrease to the pretreatment value of less than 1% after diets containing PG were discontinued. 51Chromium-labeled erythrocytes were used to evaluate erythrocyte survival in 4 kittens of the 10% PG-fed group and in 4 control kittens. Kittens with Heinz body formation induced by 10% PG had significantly (P less than 0.001) decreased erythrocyte-survival, compared with that for controls, with half-life of 8.3 days for kittens of the PG group, compared with 12.6 days for kittens of the control group.     

Heinz body hemolytic anemia associated with high plasma zinc concentration in a dog

Acute zinc toxicosis from the ingestion of pennies was diagnosed in a dog with Heinz body hemolytic anemia (PCV = 14%), leukocytosis (51,000 cells/ml) with a left shift (3,060 band neutrophils; 37,740 segmented neutrophils) and monocytosis (4,080 cells/ml), azotemia (BUN = 60 mg/dl), bilirubinemia (total bilirubin = 5.3 mg/dl), hypokalemia (3.0 mEq/L), high serum alkaline phosphatase activity (691 U/L), high total plasma solids (8.1 g/dl), hemoglobinuria, and proteinuria. Despite aggressive medical treatment, renal failure ensued, and the dog died of cardiac arrest. The clinical signs, clinical course, and laboratory findings in this dog were similar to what has been reported in other cases of acute zinc toxicosis in dogs, with the exception of a history of generalized seizures and the findings of Heinz bodies. Although a causative relationship between plasma zinc values and Heinz body formation cannot be proven, their association suggests that oxidative damage to erythrocyte hemoglobin and cell membrane proteins may be involved in the pathogenesis of zinc-induced hemolysis.     

Sequential morphological changes in chicken erythrocytes after in vivo and in vitro exposure to phenylhydrazine-hydrochloride

In acute haemolytic anaemia of chickens, induced with the oxidant chemical phenylhydrazine-hydrochloride, maximum degenerative changes in the in vivo exposed erythrocytes occurred on day 3 after injection. Microspherocytic transformation, dumb-bell shaped red blood cells and foamy squashed nuclei predominated. Heinz body formation was the cytoplasmic hallmark of the haemolytic anaemia. Marked reticulocytosis on day 5 indicated spontaneous regeneration. In vitro exposure to the chemical agent evoked similar morphological aberrations/Heinz bodies, microspherocytic transformation and nuclear degeneration. These were induced much earlier, presumably because of the absence of a protective internal milieu. Nevertheless, a basic similarity in morphology was evident. The in vitro test system might be suitable for screening oxidant chemicals and drugs.     

Spontaneous hemangiosarcoma in the spleen and liver of a young rat

Spontaneous hemangiosarcoma in young rats is rare. In this report, we describe a case of a spontaneous hemangiosarcoma in the spleen and liver of young rats. At necropsy, multiple pale red masses were observed in the spleen. Histopathologically, solid growth and haphazardly arranged neoplastic cells were observed, although no characteristic growth pattern was observed. In contrast, irregularly sized small slit-shaped spaces containing erythrocytes were found among the neoplastic cells. Reticular fibers incompletely surrounding the neoplastic cells were observed by silver staining. Immunohistochemistry revealed that the neoplastic cells were positive for vWF and CD34. Electron microscopic examination revealed that the neoplastic cells had erythrocytes in the lumen and Weibel-Palade bodies in the cytoplasm and were arranged along a discontinuous basal lamina. These features indicate that the tumor originated from vascular endothelial cells. Based on these results, the tumor was diagnosed as a hemangiosarcoma in the spleen and liver.     

Benzocaine-induced methemoglobinemia in dogs

Methemoglobinemia developed in three dogs after the owners' use of benzocaine-containing products for topical treatment of the dogs' pruritic skin conditions. The products were intended for use in man. In two of the dogs, clinical signs of shock were observed within a few hours after the application of a skin lotion containing 5% benzocaine. Methemoglobin was assayed in one case and found to be 51% of total hemoglobin. Both dogs recovered after whole blood transfusions were given. The third dog, which had been treated for several weeks with small amounts of an anesthetic aerosol containing 20% benzocaine, was anorectic and lethargic when examined. Methemoglobin content was 30%, and Heinz bodies were observed in 20% of the erythrocytes. The methemoglobin content and proportion of Heinz bodies decreased rapidly after use of the spray was discontinued. The two benzocaine-containing products incriminated in development of the methemoglobinemia did not induce measurable increases in methemoglobin content in clinically normal dogs, when applied to unbroken skin. Small increases in methemoglobin content were measured, however, when these products were given orally to clinically normal dogs. It was concluded that the skin lesions in the three clinically affected dogs enhanced absorption of the drug, resulting in methemoglobin formation.     

Onion poisoning of young cattle

Eighty-five cattle (calves and yearlings) were allowed 1000 kg of onions (Allium cepa) a day. Signs of poisoning were observed after five days; 22 animals were affected, one fatally. New illnesses continued to occur for five days after the withdrawal of onions from the diet. Clinical signs included inappetance, tachycardia, staggering and collapse, with jaundiced conjunctivae and haemoglobinuria. Haemolytic anaemia with Heinz bodies in the red cells and leucocytosis were demonstrated.     

Contribution of propylene glycol-induced Heinz body formation to anemia in cats

Propylene glycol (PG) is a common preservative and source of synthetic carbohydrates in soft-moist pet foods. Propylene glycol was fed to cats for 5 weeks at concentrations found in commercial diets (1.6 g/kg of body weight; 12% of diet on a dry-weight basis) and for 3 weeks at concentrations exceeding usual intake (8 g/kg; 41% of diet). There was a dose-dependent increase in Heinz body percentage to 28% in cats fed the low dose of PG and to 92% in cats fed the high dose. Erythrocyte half-life, measured using [14C]-cyanate hemoglobin (Hb), decreased significantly (P less than 0.05) by 18.8% and 60% in cats fed the low and high PG doses, respectively. The PCV in cats fed the low dose was unaffected, whereas cats fed the high dose had a mean (+/- SEM) decrease in PCV from 33.5 +/- 1.05% to 26.3 +/- 1.45%, accompanied by punctate reticulocytosis and bone marrow erythroid hyperplasia. A dose-dependent increase in iron pigment was found in the liver and spleen of all cats. In cats fed the low dose of PG, erythrocyte reduced glutathione concentration actually increased from 7.02 +/- 0.56 to 9.74 +/- 0.69 mumol/g of Hb, but decreased to 2.96 +/- 0.27 mumol/g of Hb in cats fed the high dose. There was no significant increase in methemoglobin concentration. These results indicated that PG cannot be considered innocuous even at concentrations consumed by cats eating commercial diets. Heinz body-induced acceleration of RBC destruction develops in a dose-dependent manner, so that cats with greater food intake, ie, lactating queens and nursing kittens, are at greater risk for development of PG-induced Heinz body hemolytic anemia.     

Heinz Body Formation Associated With Ketoacidosis in Diabetic Cats

Oxidative damage plays an important role in the pathophysiology of diabetes and diabetic complications. Feline hemoglobin is uniquely susceptible to oxidative denaturation; therefore, Heinz body formation is a highly sensitive indicator of in vivo oxidative stress in this species. Heinz bodies also contribute to anemia. We investigated hematological and clinical biochemical changes in 30 cats with spontaneous diabetes mellitus (as compared to 15 healthy control cats) and evaluated the relationship of these changes to erythrocyte oxidative damage. Cats were categorized as ketoacidotic or nonketoacidotic based on their clinical presentation and the presence of urine ketones. Ketoacidotic cats had significantly ( P = .0009) more Heinz bodies (28.3% ± 9.1 %) than nonketotic diabetic cats (6.5% ± 1.60%) and healthy control cats (0.6% ± 0.2%). Percent Heinz bodies in diabetic cats directly correlated with plasma β-hydroxy-butyrate concentration ( r = .622; P = .0002), as well as with serum chloride concentration ( r = -0.576; P = 0.0009) and the number of monocytes ( r = .536; P = .0023). Percent Heinz bodies were negatively correlated with erythrocyte glutathione concentrations. Erythrocyte membrane lipid peroxidation was slightly but not significantly increased in diabetic cats. There were no significant associations between percent Heinz bodies and degree of anemia, hyperglycemia, or glycohemoglobin. These data indicate that ketones are associated with oxidative hemoglobin damage in cats, and suggest that ketone metabolism, ie by cytochrome P450 2E1, may be a potential source of in vivo oxygen radical generation in animals with ketosis.     

The Effects of Consecutive Day Propofol Anesthesia on Feline Red Blood Cells

This study investigated the potential for multiple exposures of propofol to induce oxidative injury, in the form of Heinz body production, to feline red blood cells. Anesthesia was induced in six healthy cats with propofol (6 mg/kg, intravenous [IV]) and maintained for 30 minutes with a propofol infusion (0.20 to 0.30 mg/kg/min, IV). The initial protocol was designed for each cat to receive 10 consecutive days of propofol anesthesia. All cats spontaneously breathed room air. Heart rate, respiratory rate, and indirect blood pressure were measured and recorded before and during anesthesia. Time to complete recovery after each infusion was measured and recorded. Heinz body analysis was performed before and after each day of propofol anesthesia. Based on predetermined criteria for discontinuing daily infusions, the mean number of consecutive days of propofol anesthesia was six and propofol administration did not continue beyond 7 days in any cat. Heart rate, respiratory rate, and indirect blood pressure did not change significantly during propofol anesthesia compared with awake values. Following the third consecutive day of propofol anesthesia, there was a significant increase from baseline in the mean percentage of Heinz bodies. Hemolysis was not detected in any cat. Recovery time significantly increased after the second consecutive day of propofol anesthesia compared with the first day. Five of six cats developed generalized malaise, anorexia, and diarrhea on day 5, 6, or 7, and two cats developed facial edema. All clinical signs resolved without treatment 24 to 48 hours after discontinuing propofol anesthesia. This study suggests that consecutive day propofol anesthesia in normal cats can induce oxidative injury to feline red blood cells in the form of excessive Heinz body formation, result in increased recovery times, and result in clinical signs of illness.     

Pathological Changes in Virus Enteritis of Mink

The lesions which characterize viral enteritis of mink (VEM) were studied in twenty-six, ten-week-old mink which had been infected by force feeding a tissue suspension containing a Wisconsin strain of mink enteritis virus. The pathogenesis of the lesions was reconstructed from gross and histopathological changes observed in animals which were selected randomly from the group each day for necropsy during the course of the disease.

Alterations were observed in the tissues of all mink examined from post-inoculation day (PID) 4 through 13. The principal macroscopic lesions which consisted of fibrinous enteritis, enlargement and hemorrhage of the spleen and edema of mesenteric and hepatic lymph nodes were most conspicuous on PID 7 and 8. Histopathological changes including necrosis and desquamation of intestinal epithelium, depletion of mature lymphocytes in lymph nodes, thymus and spleen and loss of partly differentiated myeloid and erythroid cells from spleen and bone marrow also reached full development on PID 7 and 8. However, nuclear inclusion bodies which were presumed to be a product of the causative agent and, therefore, of diagnostic significance were most prevalent on PID 3, 4 and 5. The inclusions were observed in mucosal epithelial cells of the intestine, parenchymal cells of the liver and in lymphocyte precursor cells of the spleen, intestinal lymph nodules and masenteric and hepatic lymph nodes.