Cell Morphology Flashcards
Erythrocytes of what species?
Normal Canine
Morphology: relatively large, uniform red blood cells with central pallor.
Lifespan: 110 – 120 days
Erythrocytes of what species
Normal Feline
“Morphology: relatively small red blood cells with some variability in size and shape and little to no central pallor.
Lifespan: 65 – 76 days
Erythrocytes of what species?
Normal Equine
Morphology: relatively small, uniform red blood cells with little to no central pallor.
Lifespan: 140 – 150 days
Other features: rouleaux may be prominent in healthy horses. Polychromatophils are not observed in blood of healthy horses and rarely observed with anemia (degree of regenerative response to anemia in horses cannot be assessed by quantifying reticulocytes). Foals (up to 1 year of age) may show microcytosis due to physiologic iron deficiency.”
Erythrocytes of what species?
Normal Bovine
Morphology: relatively small red blood cells with mild anisocytosis and a small amount of central pallor.
Lifespan: 160 days
Other features: basophilic stippling common with regenerative response. Young calves (< 3 months) may show marked poikilocytosis, thrombocytosis, and microcytosis (microcytosis may persist up to 1 year of age due to physiologic iron deficiency). Polychromatophils are rare in healthy cattle.”
Erythrocytes of what species?
Normal Camelid
Morphology: llamas, alpacas, and camels have small, flat, oval-shaped red blood cells.
Lifespan: 60 days
Other features: mild anisocytosis and poikilocytosis may be present in healthy llamas. Mean corpuscular hemoglobin concentration (MCHC) in camelids are significantly higher than other species (usually 40-50 g/dL).”
What is this abnormal morphology?
Acanthocytes
“Morphology: red blood cells with irregular spicules projecting from the cell surface. Spicules are variable in shape (blunt or bulbous tips), variable in size, and unevenly distributed around the periphery of the cell.
Look alike: echinocytes
Clinical relevance: may be associated with certain underlying disorders including hemangiosarcoma (dogs), liver disease (dogs and cats), disseminated intravascular coagulation (dogs), vasculitis (dogs), iron deficiency anemia (dogs). May also be observed in animals on high lipid diets. Small numbers may be normal in young ruminants (calves).”
What is this abnormal morphology?
Echinocytes
“Morphology: red blood cells with small, regular spicules projecting from the cell surface. Spicules are uniform in shape with sharp or blunt tips, uniform in length, and evenly spaced around the periphery of the cell.
Look alike: acanthocytes
Clinical relevance: usually an artifact with no pathological significance (stored blood, excess EDTA, increased blood pH). May occasionally be observed with certain drugs (furosemide in horses, doxorubicin in dogs and cats). May occasionally be observed with certain disorders (electrolyte depletion, glomerulonephritis, snake envenomation, burns, bee stings).”
What is this abnormal morphology?
Eccentrocytes
“Morphology: red blood cells with a clear crescent-shaped area along one side of the periphery. Formed by the fusion of two layers of oxidized cell membrane with no hemoglobin in between.
Commonly seen with: Heinz bodies
Clinical relevance: indicates oxidant injury to red blood cells. Oxidant injury may result from certain drugs (propofol and acetaminophen in cats) or from toxins (onions, red maple leaves in horses, zinc in dogs, copper in sheep, anticoagulant rodenticide in dogs, and skunk musk in dogs). Oxidant injury may also result from certain diseases (lymphoma and diabetes mellitus in dogs).”
What is this abnormal morphology?
Keratocytes
“Also called: blister cells (vesicle), helmet cells (ruptured)
Morphology: red blood cells with a blister-like vesicle on the margin, or a bite-shaped defect with horn-like projections on the margin (which results from rupture of vesicle).
Commonly seen with: schizocytes and acanthocytes (if caused by fragmentation injury), microcytosis and hypochromia (if caused by iron deficiency), eccentrocytes and Heinz bodies (if caused by oxidant injury)
Clinical relevance: indicates fragmentation injury to red blood cells related to vascular abnormalities (ie. disseminated intravascular coagulation, glomerular disease, vasculitis, hemangiosarcoma), mechanical fragility of red blood cells (ie. iron deficiency), or oxidant injury (ie. toxicity). May be associated with hepatic lipidosis in cats. Small numbers of keratocytes may be normal in healthy cats. “
What is this abnormal morphology?
Schizocytes
Also called: schistocytes
Morphology: red blood cell fragments. Usually oblong with irregular margins, but may appear in a variety of shapes and sizes.
Commonly seen with: keratocytes and acanthocytes (if caused by fragmentation injury), microcytosis and hypochromia (if caused by iron deficiency)
Clinical relevance: indicates fragmentation injury to red blood cells related to vascular abnormalities (ie. disseminated intravascular coagulation, glomerular disease, vasculitis, portosystemic shunts, hemangiosarcoma) or mechanical fragility of red blood cells (ie. iron deficiency). Small numbers of schizocytes may be normal in healthy dogs.”
What is this abnormal morphology?
Spherocytes
“Morphology: red blood cells with a spherical rather than biconcave shape. Spherocytes appear smaller than normal red blood cells, with loss of central pallor in dogs.
Look alike: microcytes (may be difficult to distinguish microcytes from spherocytes in cats, horses, and cattle due to lack of central pallor in normal red blood cells)
Commonly seen with: other features of immune-mediated hemolytic anemia (IMHA) including ghost cells, polychromatophils, and agglutination of red blood cells
Clinical relevance: large numbers of spherocytes are associated with IMHA. Spherocytes may also be observed in stored or transfused blood. Very small numbers of spherocytes in the feathered edge may not have any clinical significance. Presence of spherocytes does not usually affect mean cell volume (MCV) on CBC because cell volume is the same (cell has decreased diameter but increased roundness).”
What is this abnormal morphology?
Poikilocytosis
“Morphology: poikilocyte is a generic term to describe red blood cells with abnormal shape. Poikilocytosis refers to large numbers of abnormally shaped red blood cells.
Commonly seen with: poikilocytosis may include acanthocytes, echinocytes, eccentrocytes, keratocytes, and schizocytes as well as red blood cells with abnormal shape that do not fit available descriptors. Poikilocytosis may be accompanied by features of various underlying disorders.
Clinical relevance: depends on number, shape, and context. Marked poikilocytosis may be normal in young ruminants, some goat breeds, and pigs with artifactual crenation of erythrocytes. Pathological poikilocytosis is common in sick cats (ie. liver disease, cardiomyopathy, etc) and in animals receiving chemotherapy.”
What is this abnormal morphology?
Codocytes
Also called: target cells
Morphology: canine red blood cells with a bullseye appearance. Caused by increased ratio of cell membrane to hemoglobin content which results in a central bulge.
Look alike: torocytes
Clinical relevance: may be associated with regenerative anemia (polychromatophilic codocytes), iron deficiency anemia (hypochromic codocytes), liver disease and hypercholesterolemia (normochromic codocytes). Only observed in canine red blood cells with central pallor.”
What is this abnormal morphology?
Macrocytes
Morphology: red blood cells that are larger than normal, may be hypochromic or normochromic.
Look alike: polychromatophils (also larger than normal but stain dark purple).
Commonly seen with: other features of regenerative anemia (polychromatophils, anisocytosis, basophilic stippling).
Clinical relevance: commonly associated with regenerative anemia. In horses, macrocytosis may be the only observable feature of regenerative anemia. May be normal in Poodles. Macrocytosis usually corresponds to increased mean cell volume (MCV) on CBC.”
What is this abnormal morphology?
Microcytes
Morphology: red blood cells that are smaller than normal. May be hypochromic or normochromic. Central pallor is preserved (in dogs).
Look alike: spherocytes (may be difficult to distinguish spherocytes from microcytes in cats, horses, and cattle due to lack of central pallor in normal red blood cells).
Commonly seen with: other features of iron deficiency anemia (hypochromasia).
Clinical relevance: often associated with iron deficiency and portosystemic shunts. May be normal in young animals (puppies and kittens 4-8 weeks of age, calves and foals up to 1 year of age) due to physiologic iron deficiency. May also be normal in Japanese dog breeds (Akita, Shiba Inu). Microcytosis usually corresponds to decreased mean cell volume (MCV) on CBC.”
What is this abnormal morphology?
Anisocytosis
Morphology: variation in red blood cell size due to the presence of red cells larger than normal (macrocytes and polychromatophils), red cells smaller than normal (microcytes and spherocytes), or both.
Commonly seen with: features of regenerative anemia (macrocytosis and polychromatophils), features of iron deficiency (microcytosis and hypochromasia), features of IMHA (spherocytes, ghost cells, agglutination).
Clinical relevance: depends on underlying condition.”
What is this abnormal morphology?
Polychromatophils
Morphology: immature red blood cells that stain dark purple on Romanowsky stains (Wright’s, Diff-Quick) due to retained cytoplasmic RNA. Larger than normal red cells.
Commonly seen with: features of regenerative anemia (macrocytosis, anisocytosis, nucleated red blood cells)
Polychromatophils versus reticulocytes: both are immature red blood cells containing RNA. Reticulocytes stain blue with new-methylene blue. Polychromatophils stain purple with Romanowsky stains. Aggregate reticulocytes stain purple on Romanowsky stains so aggregate reticulocytes are polychromatophils. Punctate reticulocytes cannot be distinguished from normal red blood cells on Romanowsky stains.
Clinical relevance: increased polychromatophils (polychromasia) indicates that bone marrow is responding to anemia. Anemia is considered regenerative if sufficient polychromatophils are present. If a robust polychromatophilic response is not present in an anemic patient, it is important to evaluate a blood smear using new-methylene blue stain to detect reticulocytes. Horses do not release polychromatophils in response to anemia (they release macrocytes). Small numbers of polychromatophils may be normal in healthy dogs.”
What is this abnormal morphology?
Reticulocytes
Morphology: immature red blood cells that stain blue with new-methylene blue due to precipitation of retained cytoplasmic RNA. Aggregate reticulocytes are less mature with large amounts of RNA that form dark blue clumps or strands. Punctate reticulocytes are more mature with small amounts of RNA that form small blue dots.
Commonly seen with: features of regenerative anemia (macrocytosis, anisocytosis, polychromatophils, nucleated red blood cells)
Polychromatophils versus reticulocytes: both are immature red blood cells containing RNA. Reticulocytes stain blue with new-methylene blue. Polychromatophils stain purple with Romanowsky stains. Aggregate reticulocytes stain purple on Romanowsky stains stains so aggregate reticulocytes are also polychromatophils. Punctate reticulocytes cannot be distinguished from normal red blood cells on Romanowsky stains.
Clinical relevance: increased reticulocytes (reticulocytosis) indicates that bone marrow is responding to anemia. If a robust polychromatophilic response is not present in an anemic patient, it is important to evaluate a blood smear using new-methylene blue stain to detect reticulocytes. Anemia is considered regenerative if sufficient reticulocytes are present. A reticulocyte count (percentage or absolute count) quantifies the number of aggregate reticulocytes present (punctate reticulocytes are not included in the reticulocyte count because they are more mature and do not reflect current regeneration).”
What is this abnormal morphology?
Hypochromasia
Morphology: red blood cells that stain pain with increased central pallor and thin rim of hemoglobin (decreased hemoglobin content).
Look alike: torocytes (increased central pallor with normal thick rim of hemoglobin).
Commonly seen with: other features of iron deficiency (anemia, microcytes).
Clinical relevance: usually associated with advanced iron deficiency. May also be observed with other deficiencies (copper, vitamin B6) or toxicities (chronic lead poisoning). Hypochromasia can be associated with decreased mean corpuscular hemoglobin concentration (MCHC) on CBC.”
What is this abnormal morphology?
Torocytes
Morphology: red blood cells with increased central pallor and a normal thick rim of hemoglobin creating a “punched out” appearance.
Look alikes: codocytes (bullseye), hypochromasia (increased central pallor with thin rim of hemoglobin)
Clinical relevance: artifact with no clinical significance.”
What is this abnormal morphology?
Ghost cells
Morphology: red blood cells that stain very pale due to loss of hemoglobin through intravascular lysis.
Commonly seen with: other features of immune-mediated hemolytic anemia (IMHA) including spherocytes, polychromatophils, and agglutination of red blood cells.
Clinical relevance: indicates intravascular hemolysis. Most commonly observed with IMHA, but may also be associated with intravascular hemolysis caused by other conditions (oxidant injury, parasitemia, snake envenomation, hypophosphatemia).”
What is this abnormal morphology?
Agglutination
Morphology: three-dimensional clumps of red blood cells. Caused by antibodies binding red blood cells together.
Look alike: rouleaux. Agglutination can be distinguished from rouleaux with a saline dilution test: place one drop of blood on a slide, add 4 – 10 drops of 0.9% NaCl, examine the slide as a wet mount with a coverslip. Saline dilution will disperse rouleaux but not agglutination.
Clinical relevance: usually indicates immune-mediated hemolytic anemia (IMHA).”
What is this abnormal morphology?
Rouleaux
Morphology: stacks of red blood cells (like a stack of coins).
Look alike: agglutination. Rouleaux can be distinguished from agglutination with a saline dilution test: place one drop of blood on a slide, add 4 – 10 drops of 0.9% NaCl, examine the slide as a wet mount with a coverslip. Saline dilution will disperse rouleaux but not agglutination.
Clinical relevance: normal in healthy cats and healthy horses. Presence of rouleaux in dogs and cattle, or excessive rouleaux in cats and horses, indicates hyperglobulinemia (inflammation, neoplasia, renal disease).”
What is this abnormal morphology?
Basophilic Stippling
Morphology: numerous small, blue, punctate inclusions in red blood cells. Caused by spontaneous aggregation of ribosomes in the cytoplasm.
Look alike: Mycoplasma
Commonly seen with: features of regenerative anemia (macrocytes, anisocytosis, polychromatophils), features of lead poisoning (nucleated red blood cells, polychromatophils)
Clinical relevance: may be seen with regenerative anemia (especially in cattle but also in dogs and cats). May be seen with lead poisoning in the absence of anemia.”
\What is this abnormal morphology?
Heinz Bodies
Morphology: dense round granules at the periphery of a red blood cell. Result from oxidant injury to red blood cells which causes hemoglobin to precipitate and form intracellular inclusions.
Commonly seen with: eccentrocytes
Clinical relevance: indicates oxidant injury to red blood cells. Oxidant injury may result from certain drugs (propofol and acetaminophen in cats) or from toxins (onions, red maple leaves in horses, zinc in dogs, copper in sheep, anticoagulant rodenticide in dogs, and skunk musk in dogs).”
What is this abnormal morphology?
Howell-Jolly bodies
Morphology: small, round, dark purple inclusions within red blood cells. Usually only 1 per red cell. Howell-Jolly bodies are nuclear remnants (small fragments of non-functional nucleus that were not expelled when the red blood cell was released from the bone marrow).
Look alike: parasitemia (ie. Anaplasma marginale, Mycoplasma sp.)
Clinical relevance: normal in healthy cats and healthy horses. Presence of Howell-Jolly bodies in dogs and cattle, or excessive numbers in cats and horses, can be associated with: regenerative anemia, impaired splenic function (ie. splenectomy, corticosteroids), and erythroid dysplasias.”
What is this abnormal morphology?
Nucleated Red Blood Cells
Metarubricyte: most mature form of nucleated red blood cell (nRBC). Nuclei are small and pyknotic, often eccentric, with condensed (smooth dark) chromatin. Cytoplasm is smooth and uniform and may stain red or purple. Basophilic stippling may be present.
Rubricyte: less mature forms of nRBC. Nuclei are larger and centred with chromatin more clumped than metarubricytes. Cytoplasm may stain purple or dark blue.
Look-alike: nRBC (particularly rubricytes) may resemble lymphocytes. nRBC can be distinguished from lymphocytes based on nuclear chromatin (nRBC have small pyknotic nuclei with condensed or clumped chromatin that stains dark, while lymphocytes have larger nuclei with non-condensed heterogenous chromatin that stains lighter) and cytoplasm (nRBC have smooth uniform cytoplasm staining red to purple to dark blue with ruffled or irregular borders, while lymphocytes have slightly grainy or heterogenous cytoplasm that stains dark purple to blue with smooth round borders). See images at top of page for comparison of nRBC versus lymphocytes.
Clinical relevance: nRBC are most commonly seen in dogs, cats, and camelids with strongly regenerative anemias. Less commonly associated with other conditions such as lead poisoning, abnormal splenic function, bone marrow injury. nRBC are rare in cattle and horses, even with strongly regenerative anemias.”
What is this normal morphology?
Neutrophils
Also called: mature neutrophils, segmented neutrophils (segs), polymorphonuclear cells (PMN)
Morphology: granulocyte with an indented (segmented) nucleus and white or pale pink cytoplasm. Canine and bovine neutrophils may contain small pink cytoplasmic granules, while feline and equine neutrophils typically lack visible granules.
Look alike: other granulocytes (eosinophils, basophils)
Commonly seen with: bands (left shift), toxic change
Clinical relevance: neutrophils are the most common leukocytes in peripheral blood of healthy animals, except cattle in which lymphocytes predominate). Neutrophila (↑ neutrophils in peripheral blood) is most commonly associated with acute stress (epinephrine release), corticosteroids, inflammation, and bacterial infection.”
What is this abnormal morphology?
Bands (left shift)
Morphology: bands are immature neutrophils with an unsegmented horseshoe-shaped nucleus.
Commonly seen with: toxic change
Clinical relevance: left shift (↑ bands in peripheral blood) indicates inflammation. Left shift is more pronounced with more acute and more severe inflammation and is usually accompanied by toxic change. Inflammatory cytokines stimulate neutrophil production and release of both mature (segmented) and immature (band) neutrophils from the bone marrow.”
What is this abnormal morphology?
Toxic Change
Morphology: toxic change refers to abnormalities in the cytoplasm of neutrophils including vacuolation (clear round areas that may coalesce to create a foamy appearance), Döhle bodies (dark blue irregular granules), and cytoplasmic basophilia (darker staining of cytoplasm). Toxic change can occur in mature (segmented) and immature (band) neutrophils.
Look alike: monocytes
Commonly seen with: bands (left shift)
Clinical relevance: toxic change indicates inflammation. Usually accompanied by left shift (increased number of bands). Inflammatory cytokines stimulate neutrophil production and release of both mature (segmented) and immature (band) neutrophils from the bone marrow.”
What is this normal morphology?
Monocytes
Morphology: leukocytes with pleomorphic nuclei (usually lobulated but may be round or kidney-shaped) and blue-gray cytoplasm containing occasional vacuoles or fine pink granules. Monocytes are larger than most other leukocytes. Considerable variation in appearance within and between species.
Look alike: band neutrophils (canine monocytes may have band-shaped nuclei), lymphocytes (equine monocytes may resemble lymphocytes).
Clinical relevance: monocytosis (↑ monocytes in peripheral blood) may be associated with corticosteroids (in dogs), granulomatous inflammation, immune-mediated diseases, tissue necrosis, and neoplasia. Monocytes leave the blood and transform into macrophages within tissues, so significant inflammation or immune-mediated disease may be present without causing monocytosis.”
What is this normal morphology?
Eosinophil
Morphology: granulocyte with a segmented (often bi-lobed) nucleus and numerous pink-to-orange (eosinophilic) cytoplasmic granules. Considerable species variation in number, size, and shape of eosinophil granules. Considerable variation within and between dog breeds regarding number, size, and shape of eosinophil granules.
Look alike: other granulocytes (neutrophils, basophils)
Clinical relevance: eosinophils may be seen in small numbers in the blood of healthy animals. Eosinophilia (↑ eosinophils in peripheral blood) is usually associated with allergies/hypersensitivities or parasitic infections and is often accompanied by basophilia.”
What is this normal morphology?
Basophil
Morphology: granulocyte with a large irregularly lobulated nucleus, lavender-staining cytoplasm, and numerous purple (basophilic) cytoplasmic granules. Considerable species variation in appearance of basophils.
Look alike: mast cells, other granulocytes (neutrophils, eosinophils)
Clinical relevance: basophils are rare in the blood of healthy animals. Basophilia (↑ basophils in peripheral blood) is usually associated with allergies/hypersensitivities or parasitic infections and is often accompanied by eosinophilia.”
What is this normal morphology?
Mast cells
Morphology: leukocyte with a large round nucleus and numerous dark purple or blue cytoplasmic granules. Usually seen at the feathered edge of blood smear. Considerable variation in appearance of mast cells.
Look alikes: other leukocytes with cytoplasmic granules (basophils, eosinophils)
Clinical relevance: not present in the blood of healthy animals. In dogs, mastocytemia (↑ mast cells in peripheral blood) may be associated with neoplasia or with non-neoplastic conditions such as allergic reactions and severe inflammation (IMHA, pancreatitis, peritonitis, pleuritis, parvoviral enteritis). In cats, the presence of mast cells in the blood is almost always associated with neoplasia. Neoplastic mastocytemia may occur secondary to solid mast cell tumors (visceral or cutaneous) or due to primary bone-marrow-derived mast cell leukemia.”
What is this (ab)normal morphology?
Giant platelets
Also called: macroplatelet
Morphology: very large platelets (larger than red blood cells). Morphology may be normal or abnormal depending on underlying cause.
Clinical relevance: giant platelets are often (but not always) immature platelets produced in response to peripheral causes of thrombocytopenia. Giant platelets may be observed in healthy animals (most common in cats). Giant platelets may also result from congential disorders (inherited macrothrombocytopenias).”
What is this (ab)normal morphology?
Platelet Clumps
Morphology: clusters of numerous platelets. Platelets in clumps may be granulated (non-activated) or degranulated (activated).
Look alike: clumps of degranulated platelets must be differentiated from strands of fibrin. Platelet clumps may be embedded within strands of fibrin. Fibrin appears darker and more striated than the cytoplasm of clumped platelets.
Clinical relevance: platelet activation and clumping are common during blood collection in healthy cats. Platelet clumping may occur during conditions that lead to platelet activation including clot formation (damaged endothelium), vasculitis, endocarditis, foreign bodies (stents), infectious agent (particularly viruses), and snake venom.”
What is this parasite?
Anaplasma marginale
Morphology: small, round, dark purple inclusions located at the periphery of red cells. Usually 1 – 2 bacteria per red cell. Present in up to 90% of red cells.
Look alike: Howell-Jolly bodies
Clinical relevance: Anaplasma marginale is an intracellular bacteria that infects erythrocytes of cattle. Causes severe acute hemolytic anemia.”
What is this parasite?
Babesia
Morphology: single or multiple pear-shaped (pyriform) organisms within red blood cells. Organisms stain dark purple around the periphery and clear in the centre.
Look alike: Histoplasma capsulatum
Commonly seen with: other tick-borne rickettsial organisms (ie. Ehrlichia, Mycoplasma, Anaplasma).
Clinical relevance: Babesia sp. are parasitic protozoa that infect erythrocytes of dogs, cats, horses, sheep, and cattle. Causes hemolytic anemia and coagulopathy (ie. disseminated intravascular coagulation).”
What is this parasite?
Cytauxzoon relis
“Morphology: small ring-shaped piroplasms with a dark eccentric nucleus inside red blood cells. Usually 1 – 2 piroplasms per red cell.
Look alikes: siderocytes, Howell-jolly bodies, Babesia felis
Commonly seen with: Mycoplasma haemofelis (concurrent infection)
Clinical relevance: Cytauxzoon felis is a protozoal parasite that infects cats. Causes severe (often fatal) disease with non-specific clinical signs; pancytopenia and coagulopathy are common; post-mortem findings include hemorrhage, edema, and thrombosis.”
What is this parasite?
Mycoplasma
“Morphology: small blue cocci, rings, or rods on the surface of red blood cells. May be observed in the background between red blood cells (bacteria fall off of red cells in blood samples > 24 hours old).
Look alikes: stain precipitate (especially with blood samples > 24 hours old), basophilic stippling
Clinical relevance: Myclopasma are epicellular bacterial parasites that infect erythrocytes of dogs, cats, cattle, and pigs. Causes hemolytic anemia.”
What is this parasite?
Histoplasma
“Morphology: intracellular yeast-like organisms with a pseudocapsule in the cytoplasm of neutrophils and monocytes. May be 1 – 20 organisms per cell. Organisms may be present in > 25% of neutrophils and monocytes.
Look alike: Babesia
Clinical relevance: Histoplasma capsulatum is a dimorphic fungus that exists as a mycelial form in the environment and as a yeast form in a host’s body. Causes severe (often fatal) disease with variable clinical signs depending on organ systems affected (chronic GI signs most common in dogs, respiratory signs most common in cats).”
What is this parasite?
Setaria equina
Morphology: long worm-like organism in the background of peripheral blood smear.
Look alike: trypanosomes, other filarial organisms such as equine onchocerciasis (Onchocerca cervicalis) and canine heartworm (Dirofilaria immitis)
Clinical relevance: Setaria equina is a parasitic roundworm that infects horses. Adult worms live in the abdominal cavity and usually cause no clinical signs. Mild peritonitis may result from very heavy abdominal infestations. Blindness may result if worms develop in the eye.”
What is this parasite?
Trypanosomes
Morphology: elongated organism with undulating membrane, dark nucleus located centrally, small round purple dot (kinetoplast) located at anterior end, and flagellum extending from posterior end. Usually seen in a curved C or U shape. Some variation in appearance between Trypanosoma sp.
Look alike: microfilaria
Clinical relevance: Trypanosoma sp are parasitic flagellate protozoa that infect several domestic and wild animals. Trypanosoma cruzi infects dogs in North America and causes cardiac disease (Chaga’s disease). Trypanosoma theileria infects cattle in North America but is usually not pathogenic. Some species of Trypanosoma may cause hemolytic anemia.”
