Case Studies

Case 1: Feline 8 Month Old Intact Male DSH
Case 2: Canine 6 Year Old Castrated Male Dachshund
Case 3: Canine 15 Year Old Castrated Male Cocker Spaniel
Case 4: Canine 5 Year Old Spayed Female Sheepdog
Case 5: Feline 4 Year Old Castrated Male Domestic Longhair
Case 6: Canine 11 Year Old Female Husky
Case 7: Canine 4 Week Old Male Greyhound
Case 8: Canine 5 Year Old Female Cocker Spaniel
Case 9: Canine 2 Year Old Intact Female Labrador
Case 10: 9 Year Old Neutered Male Gordon Setter
Case 11: Feline 10 Month Old Female Siamese
Case 12: Canine 1 Year Old Intact Male Collie
Case 13: Canine 1 Year Old Intact Female Boxer
Case 14: Feline 10 Year Old Castrated Male Tabby DSH
Case 15: Canine 14 Year Old Intact Female Cocker Spaniel
Case 16: Feline 9 Year Old Spayed Female Persian
Case 17: Feline 4 Year Old Intact Female DSH
Case 18: Canine 10 Year Old Female Sheltie
Case 19: Feline 4 Year Old Male DSH
Case 20: Canine 9 Year Old Female Golden Retriever
Case 21: Canine 2 Year Old Standard Poodle
Case 22: Canine 6 Year Old Male English Bull Dog
Case 23: Canine 9 Year Old Castrated Male Mixed Breed
Case 24: Canine 9 Year Old Spayed Female Corgi
Case 25: Canine 11 Year Old Spayed Female Basset Hound
Case 26: Feline 7 Year Old Male Domestic Shorthair
Case 27: Canine 12 Year Old Mixed Breed Male
Case 28: Canine 7 Year Old Mixed Breed Spayed Female
Case 29: Canine 5 Year Old Mixed Breed Intact Male

Case 1: Feline 8 Month Old Intact Male DSH

History

Cat presented for castration and declaw surgery.

Physical Examination

Normal temperature, pulse, and respiration (TPR). Cat is extremely fractious and is salivating profusely.

Discussion/Interpretation

CBC reveals a marked lymphocytosis with a slight mature neutrophilia. Causes of lymphocytosis include chronic infection or inflammation, lymphocytic leukemia, and physiologic lymphocytosis. Examination of the blood film reveals numerous small lymphocytes. Lymphoblasts or atypical lymphocytes were not observed. Tests for FeLV and FIV were negative.

This is an example of a physiologic lymphocytosis and neutrophilia in a young, healthy, scared cat. Epinephrine release causes demargination of neutrophils and lymphocytosis. Both changes are transient and values return to normal within 1 - 2 hours.

Case 2: Canine 6 Year Old Castrated Male Dachshund

History

Back pain with posterior paresis for 2 days.

Physical Examination

Intervertebral disc protrusion at T13 - L1.

Discussion/Interpretation

The leukogram reveals a lymphopenia, eosinopenia, and a leukocytosis due to a neutrophilia without a left shift and a monocytosis. These changes represent the effects of glucocorticoid therapy. The dog had been given 3 mg/kg dexamethasone 2 days prior to the CBC. Glucocorticoids cause a mature neutrophilia by increasing release of mature neutrophils from the marrow storage pool, demarginating neutrophils from the marginal neutrophil pool (MNP) into the circulating neutrophil pool (CNP), and decreasing neutrophil migration into tissues. The leukocyte changes will revert to normal within a few days after cessation of glucocorticoid therapy. It is important that this leukocyte pattern not be confused with the response seen with inflammation.

This leukocyte pattern also can be typical of hyperadrenocorticism.

Case 3: Canine 15 Year Old Castrated Male Cocker Spaniel

History

Vomiting for 5 days.

Physical Examination

Dog is obese, depressed, and severely dehydrated.

Discussion/Interpretation

History of vomiting suggests that hyperproteinemia is due to dehydration. A leukocytosis is present due to a neutrophilia with a left shift (Fig. c3-1) and monocytosis. Toxic change is evident in circulating neutrophils. The leukocyte pattern indicates acute inflammation with tissue necrosis. An abdominocentesis revealed a septic neutrophilic exudate (Fig. c3-2). Serum amylase and lipase activities were both increased. The clinical diagnosis was necrotizing pancreatitis with septic peritonitis.

Figure c3-1.Canine toxic band neutrophil. Inflammation or toxemia causes morphologic changes in neutrophils. In this band neutrophil, cytoplasmic basophilia, vacuolation, and a Dohle body are evident (100x).

Figure c3-2.Abdominal fluid. Swollen degenerate neutrophils with phagocytosed bacteria indicate septic peritonitis which has caused a left shift with toxic neutrophils in the CBC (100x).

Case 4: Canine 5 Year Old Spayed Female Sheepdog

History

Partial anorexia and intermittent vomiting. Owner reports that dog is "not her usual self" during the last 2 weeks.

Physical Examination

No abnormalities detected.

Discussion/Interpretation

The CBC is unusual in that there is mild anemia with numerous NRBCs (metarubricytes). However, the metarubricytosis is not accompanied by significant anisocytosis, macrocytosis, polychromasia, or an increase in reticulocytes (Fig. c4-1). In addition, the anemia is mild and the number of NRBCs is out of proportion to the severity of anemia. This is a nonregenerative anemia because the response is disordered and causes of inappropriate metarubricytosis should be pursued. These include marrow neoplasia, myelofibrosis, lead poisoning, myelophthisis, extramedullary hematopoiesis, or severe anoxia. Basophilic stippling can be associated with lead poisoning but is not a consistent feature (Fig. c4-2). Basophilic stippling can also be seen in blood films of dogs and cats with intense erythrogenic responses to severe anemia. In this dog, the inappropriate release of metarubricytes and the stippling are reasons to submit blood for lead analysis. The blood lead level was 1.6 ppm (normal Pb <0.35 ppm). A neutrophilic leukocytosis and monocytosis are present suggesting an inflammatory response with tissue necrosis.

Diagnosis

Inappropriate metarubricytosis due to lead poisoning.

Figure c4-1.Canine blood. Several NRBCs are noted in the field that are not accompanied by polychromasia or anisocytosis. In a dog that has a very mild anemia, the NRBCs represent an inappropriate response. Causes of inappropriate metarubricytosis include acute anoxia, marrow neoplasia, myelofibrosis, extramedullary hematopoiesis, myelophthisis and lead poisoning (40x).

Figure c4-2. Canine blood. RBCs are crenated and several target cells are noted. Basophilic stippling is evident in the large RBC in center of the field as blue-black granules in the periphery of the cytoplasm. Basophilic stippling is an inconsistent finding in lead poisoning (120x).

Case 5: Feline 4 Year Old Castrated Male Domestic Longhair

History

Weight loss, anorexia, and listless for 3 weeks. Owner reports that cat never goes outside.

Physical Examination

Mucous membranes are white, rapid pulse, moderate weight loss, enlarged spleen and liver.

Discussion/Interpretation

The uncorrected WBC count was 77,200/ul. The difference between this value and the reported WBC count is due to the correction for NRBCs. Severe anemia is present with an increase in MCV and numerous NRBCs. However, the increased MCV and metarubricytosis are not accompanied by anisocytosis, polychromasia, or reticulocytosis (Fig. c5-1). The anemia in this cat is nonregenerative because the morphologic response was not orderly or proportional to the severity of anemia. Blast cells were quite large and had dark blue cytoplasm, focal perinuclear clear zone, round eccentric nucleus, and a single large nucleolus (Fig. c5-2a, Fig. c5-2b and Fig. c5-3). Mitotic figures were noted occasionally. The presence of blast cells, nonregenerative anemia, and thrombocytopenia are indications for bone marrow examination. The increase in MCV is probably due to macrocytosis and the fact that the electronic counter is including large leukocytes and blast cells in the RBC volume analysis. FeLV antigen test was positive. A bone marrow aspirate revealed diffuse infiltration with blast cells identical to those seen in blood (Fig. c5-4). Developing granulocytes and megakaryocytes were infrequent.

Diagnosis

Myeloproliferative neoplasm (Erythroleukemia).

Figure c5-1. Feline blood. Numerous NRBCs are present without any evidence of polychromasia, macrocytosis, or anisocytosis. These findings indicate that the anemia is nonre- generative. Platelets are not observed in the field (100x).

Figure c5-2a. Blast cells (arrow) are noted that are larger than a neutrophil and have an eccentric nucleus, irregular chromatin, prominent nucleoli, and focal clear zone in a dark basophilic cytoplasm.

Figure c5-2b. Large amorphous pink staining aggregates (arrows) are disintegrated nuclei (100x).

Figure c5-3. Peripheral edge of smear. Numerous disintegrated nuclei of blast cells are concentrated on the feather edge of the smear. Blast cells are fragile and tend to fragment during the preparation of smears (100x).

Figure c5-4. Bone marrow. Nonregenerative anemia, NRBCs without polychromasia, and blast cells are clear indications for bone marrow examination. Normal granulocytic and erythroid cells have been replaced by a homogenous population of blast cells identical to those seen in blood. Because of this neoplastic proliferation, the cat is severely anemic, thrombocytopenic, and leukopenic (100x).

Case 6: Canine 11 Year Old Female Husky

History

Weight loss, diminished appetite, decreased exercise tolerance, loose stools for several weeks.

Physical Examination

Pale mucous membranes, dark tarry stools. Dog is fractious and difficult to examine.

Discussion/Interpretation

Severe anemia and hypoproteinemia are evident. On initial inspection, it appears there is a regenerative response because of the anisocytosis, polychromasia, NRBCs, and reticulocyte increase. Several findings indicate that the regenerative response is abnormal. The RBC indices and morphology reveal a microcytic and hypochromic anemia (Fig. c6-1a and Fig. c6-1b) instead of the normal regenerative response to blood loss, which is macrocytic and hypochromic. Although the reticulocyte percentage is increased slightly, the absolute reticulocyte count does not indicate a significant reticulocyte response. Serum iron and serum iron binding capacity were measured and confirmed iron deficiency (Iron = 38 ug/dl, Reference Range 89 - 138; IBC = 360 ug/dl, Reference Range 177 - 400). Although the change can be subtle, RBCs in iron deficient animals are smaller and have a much larger area of central pallor due to insufficient hemoglobin content (Fig. c6-2).

Polychromatophilic RBCs and NRBCs are poorly hemoglobinated and have a vacuolated or moth-eaten cytoplasms. Marked poikilocytosis and thrombocytosis are also features of iron deficiency. A mature neutrophilia, monocytosis, and lymphocytosis are evident in the leukogram and are consistent with chronic inflammation. A new steady state in neutrophil kinetics has evolved characterized by increased neutrophil production in marrow that is equal to tissue demand. Atypical lymphocytes or lymphoblasts were not observed on the blood film. The dog was sedated for a more thorough examination which revealed a firm mid-abdominal mass. Ultrasound examination confirmed an intestinal mass with mixed echogenicity. Fine needle aspiration of the abdominal mass revealed a pleomorphic population of epithelial cells (Fig. c6-3).

Diagnosis

Intestinal carcinoma (Fig. c6-4) with chronic GI hemorrhage that caused a secondary iron deficiency anemia.

Figure c6-1a. Canine blood. Blood from the dog in Case 6 is compared with normal canine RBCs. A. Microcytosis and hypochromia is pronounced when compared with the normal RBCs in B (40x).

Figure c6-1b. Canine blood. Blood from the dog in Case 6 is compared with normal canine RBCs. A. Microcytosis and hypochromia is pronounced when compared with the normal RBCs in B (40x).

Figure c6-2. Canine blood. Microcytes, poikilocytes, and hypochromic RBCs are evident. Hypochromic RBCs have a larger area of central pallor with a thin and reduced rim of hemoglobin staining. Iron deficiency anemia is the most frequent cause of these changes in dogs and cats (100x).

Figure c6-3. Aspirate of abdominal mass. A sheet of pleomorphic epithelial cells with marked anisocytosis, anisokaryosis, variable N:C ratios, and irregular chromatin confirms the presence of carcinoma (100x).

Figure c6-4. Loop of bowel with large carcinoma. Note the ulcerated luminal surface which caused chronic hemorrhage and secondary iron deficiency anemia.

Case 7: Canine 4 Week Old Male Greyhound

 History

Puppy was healthy at birth and during the first week of life. At 2 - 3 weeks of age, puppy became acutely depressed, stopped eating, and seemed pale. In spite of supportive care, about 50 - 60% of puppies in previous litters died within a few days of showing clinical signs.

Physical Examination

Moderate depression, weakness, lack of appetite, fever (T= 103.8°F) and mucous membranes are pale and icteric. Feces are formed and bright orange in color. The spleen is enlarged. The puppy is heavily infested with ticks.

Discussion/Interpretation

The RBC morphology and reticulocytosis indicate regenerative anemia. Icterus, bilirubinuria, splenomegaly, and orange colored feces and the absence of hemorrhage indicate hemolytic disease. Causes of hemolysis include infectious agents, toxins, immune-mediated destruction, fragmentation, osmotic lysis, and congenital hemolytic disease. The blood films were reexamined for the presence of RBC parasites, Heinz bodies, spherocytes, schistocytes, and ghosts. Serologic tests for Leptospira were negative. A direct Coombs’ test was positive. A few Babesia canis organisms were identified in RBCs on the initial blood film (Fig. c7-1). Impression smear of spleen from a dead puppy revealed numerous Babesia organisms within RBCs (Fig. c7-2). Puppies were treated with diminazene aceturate. Aggressive tick control was initiated to control the transmission via ticks.

Figure c7-1. Babesia canis. Pairs of basophilic, pyriform, protozoal organisms are noted in the RBCs. Stain precipitate is also present as basophilic granules covering some RBCs (100x).

Figure c7-2. Splenic impression smear, Babesia canis. Round to oval parasites are noted within several RBCs. Round basophilic nuclear structure is noted within each protozoal organism. Disintegrated nuclei of lymphocytes are noted as round pink amorphous aggregates (100x).

The absence of an increase in MCV and the hypoproteinemia are likely due to blood loss and iron depletion secondary to hookworm disease. Hemolytic anemia and thrombocytopenia in Babesiosis are caused by immune-mediated destruction that targets RBCs and platelets. Thus, it is not unusual for the Coombs' test to be positive.

White cell data indicate an inflammatory leukogram with superimposed stress and tissue necrosis. Such a pattern is common in hemolytic conditions. The cause of the inflammatory response is the destruction of circulating red cells.

Diagnosis

Hemolytic anemia due to Babesia canis complicated by hookworm disease.

Case 8: Canine 5 Year Old Female Cocker Spaniel

History

Owner states that dog is not well and that urine appears very dark. Treated with antibiotics for a bladder infection by the previous veterinarian.

Physical Examination

T=104°F, mucous membranes are pale and icteric, large firm mass in mid-abdomen. Mild dehydration is present.

Discussion/Interpretation

The clinical presentation and laboratory data could lead in several different directions. Icterus, increased total bilirubin and increased ALT activity could indicate liver disease. Abdominal mass, fever, neutrophilic leukocytosis, left shift and monocytosis are compatible with inflammatory disease such as pyometra in an intact female.

Icterus can be caused by hemolytic disease, hepatic disease, or bile duct obstruction. In an icteric animal, always check first for evidence of hemolytic anemia. The CBC results indicate a marked regenerative response (increased reticulocytes and MCV) and the slide examination reveals anisocytosis, polychromasia, macrocytosis, NRBCs, and numerous spherocytes and ghosts (Fig. c8-1, Fig. c8-2, Fig. c8-3, and Fig. c8-4). These findings are consistent with hemolytic anemia due to immune-mediated RBC destruction. No RBC parasites were observed. The increased total protein is likely due to dehydration.

The leukocytosis with left shift is very pronounced but can be a feature of immune-mediated hemolytic anemia. The increases in ALT and total bilirubin represent the combined effects of acute RBC destruction with excess bilirubin production and secondary liver damage due to hypoxic injury as a result of severe acute anemia.

Figure c8-1. RBCs from dog with immune-mediated hemolytic anemia. Anisocytosis is marked due to the presence of macro- cytic polychromatophilic erythrocytes and spherocytes (arrow) which are the smaller cells that lack the normal central pallor (60x).

Figure c8-2. RBC agglutination. Clustering of RBCs in variable groups indicates that agglutination is present. This change is caused by antibody bridging between adjacent RBCs (60x).

Figure c8-3. Spherocytes and ghost RBCs are present. The latter indicate some degree of intravascular lysis (100x).

Figure c8-4. Marked regenerative response is evidenced by marked anisocytosis, macrocytosis, and polychromasia. Smaller RBCs without central pallor are spherocytes.

Diagnosis

Immune-mediated hemolytic disease, Coombs' positive.

Outcome

Responded to prednisone therapy.

Case 9: Canine 2 Year Old Intact Female Labrador

History

Forelimb lameness, fever and loss of appetite for 3 weeks. Dog was treated with antibiotics for 2 weeks with no improvement.

Physical Examination

T 105°F, pain in right humerus, cough with moist rales, enlarged peripheral lymph nodes. No evidence of dehydration.

Discussion/Interpretation

Mild anemia is evident with increased total protein concentration. Anemia is normocytic and normochromic (Fig. c9-1). Physical examination reveals no evidence of hemorrhage. Reticulocyte count and RBC morphology indicate no evidence of regeneration, which should be expected with hemorrhage or hemolysis and a 3 week history of disease. The increase in total protein can be due to dehydration or increased globulin synthesis in response to infection/inflammation. Since there is no evidence of dehydration, hyperglobulinemia is the likely cause. The WBC count is increased due to a moderate to marked neutrophilia with a monocytosis and a minimal left shift (2% of the WBCs in the differential count are band neutrophils). These findings are consistent with chronic inflammation. The decrease in lymphocyte numbers is due to endogenous glucocorticoid release or stress response.

The bone marrow was cellular with an increased myeloid:erythroid (M:E) ratio (Fig. c9-2). Granulopoiesis was active with normal maturation. Erythroid precursors were reduced in number but maturation appeared normal. Marrow iron stores were increased.

Figure c9-1. Canine blood. Normocytic, normochromic RBCs indicate that the anemia is nonregenerative. Segmented neutrophil and monocyte are in the field. Neutrophilia and monocytosis indicated chronic inflammation with tissue necrosis (100x).

Figure c9-2. Bone marrow. Granulocytic hyperplasia and erythroid hypoplasia are evident in the marrow smear. The majority of cells are developing granulocytes with a marked reduction in erythroid activity. The CBC and marrow changes are consistent with chronic inflammation (40x).

Summary

Nonregenerative anemia, hyperglobulinemia, and neutrophilic leukocytosis with minimal left shift and monocytosis. Bone marrow has increased iron stores and a predominance of granulocytic cells with a reduction in erythroid precursors indicating granulocytic hyperplasia and erythroid hypoplasia. These findings are consistent with anemia of inflammation.

Outcome

Fine needle aspirate of lymph nodes and lung reveal pyogranulomatous inflammation due Blastomyces dermatitidis (Fig. c9-3).

Figure c9-3. Aspirate of lymph node. Pyogranulomatous inflammation is present in the node. Majority of cells are neutrophils and macrophages with a broad-based budding yeast visible to the right of center. Morphology of yeast is consistent with Blastomyces dermatitidis.

Case 10: 9 Year Old Neutered Male Gordon Setter

 History

Adopted from humane society 1 year ago. Owner has noticed increased hair shedding and decreased physical activity.

Physical Examination

Normal body temperature. Increased pulse rate. Bilaterally symmetrical alopecia with severe weakness, weight loss, and pale mucous membranes. Abdominal mass detected on abdominal palpation.

Discussion/Interpretation

A severe anemia is present with normal RBC indices and no evidence of regeneration in the RBC morphology or reticulocyte count (Fig. c10-1). Severe thrombocytopenia, leukopenia, and neutropenia are present. These findings indicate a severe decrease in circulating blood cells or pancytopenia. Bone marrow aspiration is indicated.

Bone marrow examination revealed a severely hypocellular marrow with very few erythroid, granulocytic, or megakaryocytic precursors (Fig. c10-2). An occasional capillary fragment is noted. Most of the marrow has been replaced with fat tissue.

Figure c10-1. Bone marrow. Replacement of the normal marrow cells with adi- pose tissue and connective tissue indicates severe marrow hypoplasia. Reduction in marrow activity results in pancytopenia. This change can be caused by toxins, drugs, infectious agents, chemical injury, and immune-mediated disease.

Figure c10-2. Canine blood. Severe nonregenerative anemia and thrombocytopenia are evident. Polychromasia, anisocytosis, and macrocytosis are absent. Platelets are rarely seen (100x).

Diagnosis

Severe pancytopenia due to marrow hypoplasia/destruction. Consider toxic chemicals, drugs, infectious agents, or immune-mediated disease as possible causes.

Outcome

Ultrasound guided FNA of abdominal mass reveals a Sertoli cell tumor. Metastasis is evident in the regional lymph nodes. These tumors can secrete high levels of estrogen resulting in symmetrical alopecia and severe marrow hypoplasia. Serum estrogen levels were measured and levels were extremely high. Because of metastatic disease in the iliac and sublumbar lymph nodes, the owner elected euthanasia. The owner subsequently discovered that the dog had not been neutered and was a bilateral cryptorchid

Case 11: Feline 10 Month Old Female Siamese

History

Straining in an attempt to deliver kittens.

Physical Examination

T =104.9ºF, depressed, dehydrated, serohemorrhagic vaginal discharge; radiographs reveal macerated fetuses in genital tract.

Discussion/Interpretation

Day 1

Polycythemia is due to dehydration. Normal TPP in light of severe dehydration indicates hypoproteinemia. Leukogram reveals severe degenerative left shift, lymphopenia, and toxic neutrophils (Figure c11-1, Figure c11-2, and Figure c11-3). These changes are compatible with overwhelming or peracute inflammation of a well-vascularized tissue or body cavity. The severity of the left shift (bands exceed mature neutrophils with a normal WBC count) indicates a poor prognosis. Acute peritonitis or metritis is a likely cause. Hypoproteinemia is due to protein leakage associated with acute inflammation. Abdominocentesis reveals a neutrophilic exudate with rod-shaped bacteria (Figure c11-4).

Figure c11-1. Feline blood. Increase in band neutrophils indicates a severe left shift. Increased rouleaux formation can be caused by changes in plasma proteins as a result of inflammation (40x).

Figure c11-2. Feline blood. Inflammation can produce changes in neutrophil morphology. Two segmented neutrophils are present that have a slight increase in cytoplasmic basophilia. One of the neutrophils is very large and has abnormal nuclear lobulation which is a sign of toxic change (100x).

Figure c11-3. Feline blood. RBCs are crenated with marked rouleaux formation. Band neutrophils are extremely toxic with basophilic granular cytoplasm and Dohle bodies (100x).

Figure c11-4. Abdominal fluid. Mixture of neutrophils and macrophages are present. Phagocytosed bacteria are noted. These findings confirm septic peritonitis (100x).

Day 2

Cat was given IV fluids and antibiotics prior to exploratory laparotomy. With rehydration, PCV is reduced to normal and the hypoproteinemia is evident. Leukocyte values are similar to day 1 and indicate acute overwhelming inflammation and sepsis. Severe lymphopenia on both days is due to stress response. Exploratory surgery revealed acute metritis with a uterine perforation resulting in acute diffuse peritonitis. Ovariohystorectomy and abdominal lavage were done.

Day 5

CBC is 2 days postoperative and reveals a marked neutrophilic leukocytosis with left shift and severe lymphopenia. The leukocyte response from day 2 to day 4 is caused by the abrupt removal of the site of inflammation. A rebound neutrophilia occurs because of continued production and release of neutrophils from a stimulated bone marrow. Hypoproteinemia persists and will recover gradually during the next 2 weeks. PCV is reduced due to blood loss at surgery and the presence of severe inflammation.

Outcome

Uneventful recovery.

Case 12: Canine 1 Year Old Intact Male Collie

History

Severe vomiting and diarrhea for 12 hours.

Physical Examination

T= 98°F, P 40, 8% dehydration; dog is very weak and nearly comatose.

Discussion/Interpretation

Polycythemia and hyperproteinemia are due to dehydration. The leuko- gram reveals a normal neutrophil and lymphocyte count. The leukocyte response is not indicative of inflammation or sepsis that would be significant considerations in the differential diagnosis. With the severity of clinical signs, we would expect at least a stress leukogram. A normal leukogram with these clinical signs is indicative of diminished levels of adrenal steroids that are characteristic of acute adrenocortical insufficiency (Addison's disease).

Serum chemistries revealed prerenal azotemia, hyponatremia, hyper- kalemia, and a low baseline cortisol followed by a minimal response to ACTH stimulation.

Case 13: Canine 1 Year Old Intact Female Boxer

History

Hit by car 2 days prior to admission. Owner noticed that dog was not eating and was depressed.

Physical Examination

Multiple abrasions. Area of pain over entire left side of abdomen.

Discussion/Interpretation

Day 1

A neutrophilic leukocytosis and lymphopenia are present. Toxic neutrophils or a left shift were not observed. These findings are consistent with a stress response. However, an early (mild) inflammatory response cannot be ruled out.

Day 2 (8AM)

The condition of the dog has deteriorated clinically. Depression, poor capillary refill time, and a rapid pulse are evident. The number of leukocytes and neutrophils has decreased and there is a marked left shift with toxic neutrophils (Figure c13-1). Acute inflammation or sepsis is likely. A careful search for site or organ system involved should be undertaken. Abdominocentesis revealed a septic neutrophilic exudate indicating acute peritonitis (Figure c13-2).

Figure c 13-1. Canine blood. Both neutrophils exhibit toxic change in the form of cytoplasmic basophilia, vacuolation, and Dohle bodies. RBCs are crenated (100x).

Figure c 13-2. Abdominal fluid. Numerous degenerate neutrophils that contain a mixed population of phagocytosed bacteria are present in a proteinaceous background. Cytologic findings confirm septic peritonitis (100x).

Day 2 (3PM)

Diffuse peritonitis was evident on surgical exploration. Multiple segments of infarcted bowel were resected. A CBC just prior to surgery revealed a marked reduction in neutrophil numbers with a severe degenerative left shift and toxic neutrophils. This change occurred over a 7-hour period and is indicative of severe overwhelming inflammation and a very grave prognosis. The decrease in platelets is likely due to consumption at sites of thrombosis and infarction. The dog died shortly after the surgery.

This case illustrates the dynamic and abrupt changes that can occur in the leukogram in response to acute overwhelming inflammation.

Case 14: Feline 10 Year Old Castrated Male Tabby DSH

History

Episodes of vomiting and respiratory distress. Respiratory signs are unresponsive to antibiotics.

Physical Examination

Normal body temperature with increased respiratory rate and expiratory effort. Chest radiographs reveal several nodular radiopaque densities in the lungs. Moderate dehydration is present.

Discussion/Interpretation

Increase in PCV and TPP is due to dehydration. Leukocytosis is due to a marked eosinophilia. Causes include allergy and hypersensitivity reactions, chronic granulomatous disease, and neoplasms such as mast cell tumors or lymphoma. Eosinophilic leukemia and hypereosinophilic syndrome are infrequent causes. Parasites that reside in the lung or that have a significant tissue migration phase or exposure to the immune response are frequent causes. Allergic or granulomatous diseases of the skin, respiratory tract, female genital tract or gastrointestinal tract are also likely to produce an eosinophilic leukocytosis. Because of the respiratory signs, Paragonimus (lung fluke), Aleurostrongylus (nematode), feline heartworm, and feline asthma were considered. A transtracheal wash revealed numerous eosinophils with a few macrophages (Figure c14-1). A few large, oval, rust- colored, operculated eggs (Figure c14-2) were also noted and confirm a diagnosis of Paragonimus infection.

Figure c14-1. Transtracheal wash. Numerous eosinophils are present in the transtracheal wash indicate allergy, hypersensitivity reaction, respiratory parasites, or possible heartworm infection (100x).

Figure c14-2. Transtracheal wash. Low power scan of the sample reveals a few yellow oval Paragonimus eggs. The operculum on the eggs is not visible at this magnification. This lung fluke causes severe eosinophilic inflammation in the lung and airways (20x).

Case 15: Canine 14 Year Old Intact Female Cocker Spaniel

History

Dog was presented in a state of acute collapse. The dog resides in a household with numerous pets and prior history was vague.

Physical Examination

The animal is in fair body condition and has a purulent vaginal discharge. T = 98.7°F, rapid pulse, poor capillary refill time, moderate dehydration,and congested mucous membranes.

Abdominal paracentesis: exudate with degenerate neutrophils and rod- shaped bacteria.

Discussion/Interpretation

Day 1

The PCV and TPP are at the low end of normal and indicate anemia and hypoproteinemia when considered in light of moderate dehydration. The leukogram reveals a low normal WBC count with a severe left shift and toxic neutrophils. This response indicates acute overwhelming inflammation of a large, well-vascularized tissue or organ. The inflammation is severe enough to have depleted the marrow storage pool of mature and band neutrophils and initiate release of metamyelocytes. Causes of this type of response include acute peritonitis, necrotizing pancreatitis, acute suppurative pneumonia, acute cellulitis, or GI perfo- ration. A poor prognosis is indicated because the WBC and segmented neutrophils counts are low, and band neutrophils exceed the number of segmented cells. The site of inflammation must be identified quickly and steps taken to initiate treatment.

Radiographs and abdominocentesis indicate acute septic peritonitis (Figure c15-1). Exploratory surgery revealed acute metritis with uterine perforation and peritonitis.

Figure c15-1. Abdominal fluid. Mixture of degenerate and nondegenerate neutrophils with phagocytosed rod-shaped bacteria indicates septic peritonitis (100x).

Day 3

With rehydration, anemia and hypoproteinemia are apparent. The anemia is likely due to inflammation and hemorrhage during surgery. Hemorrhage may also cause hypoproteinemia but leakage of plasma protein associated with diffuse inflammation is a factor in this case. A moderate leukocytosis with mild left shift and monocytosis is evident. Lymphopenia indicates stress. These changes are consistent with resolving inflammation and indicate that the bone marrow has repopulated the maturation pool of mature neutrophils and that the tissue demand for neutrophils has subsided. The prognosis is much improved.

Outcome

Recovery was uneventful. Reliance on total WBC counts alone in assessing the leukogram can be misleading. When the dog was in critical condition (Day 1) the total WBC count was normal. During recovery, the total WBC count was increased. However, the severe left shift and toxic neutrophils on Day 1 indicated the true magnitude and severity of disease.

Case 16: Feline 9 Year Old Spayed Female Persian

History

Cat has been treated with several drugs for respiratory and uri- nary tract infections.

Physical Examination

The cat is depressed, listless, and has pale mucous membranes.

Discussion/Interpretation

The cat has a marked regenerative anemia as evidenced by increased MCV, anisocytosis, polychromasia, reticulocytosis, and increase in NRBCs (Fig. c16-1 and Fig. c16-2). The normal TPP and physical examination eliminate hemorrhage as a cause. Hemolytic anemia can be caused by infectious agents such as RBC parasites, immune-mediated disease, fragmentation, osmotic lysis, and toxins. Heinz bodies indicate oxidative injury due to drugs, chemicals, plant sources, or metabolic disease (Fig. c16-3 and Fig. c16-4). The presence of Heinz bodies will falsely elevate the hemoglobin measurement and cause increases in the MCH and MCHC. With the marked regenerative response, a decrease in MCHC is expected but the false increase in hemoglobin causes this value to remain within the reference range. Heinz bodies can be an incidental finding in the cat but when accompanied by marked regenerative anemia, the history should be re-examined for possible causes of Heinz body hemolysis. All previous medications were examined and one was found that contained methylene blue as part of its formulation. This compound is one of several that can cause Heinz body hemolytic anemia. Other drugs to consider include acetaminophen, benzocaine, DL methionine, phenazopyridine, and vitamin K3.

Figure c16-1. Feline blood. Anisocytosis, macrocytosis, polychromasia, and several NRBCs indicate regenerative anemia (40x).

Figure c16-2. Feline blood. Two NRBCs are compared with a small lymphocyte (arrow). Platelet numbers are adequate and a few macrocytic polychromatophilic RBCs are present (100x).

Figure c16-3. Feline blood. Small rounded projections are noted on three RBCs (arrows). These inclusions are Heinz bodies which are caused by oxidative injury. The regenerative anemia in this case is due to hemolysis secondary to Heinz body formation (100x).

Figure c16-4. Feline blood, reticulocyte stain. Reticulocytes are frequent. Both aggregate and punctate reticulocytes can be seen. Heinz bodies are small rounded turquoise inclusions (arrows) on the edge of the RBC membrane (100x).

Diagnosis

Drug-induced Heinz body hemolytic anemia.

Case 17: Feline 4 Year Old Intact Female DSH

History

Anorexia, pendulous abdomen; owners believes cat is pregnant.

Physical Examination

T=104.3°F cat is depressed, dehydrated, and has a serosanguinous vaginal discharge.

Discussion/Interpretation

In light of clinical dehydration, the cat is normoproteinemic and is more anemic than the measured PCV would indicate. The anemia is mild and appears nonregenerative because of the normal reticulocyte count and RBC morphology. There is a marked leukocytosis due to a neutrophilia, pronounced left shift, lymphocytosis and monocytosis. Dohle bodies in neutrophils indicate toxic change. This leukogram is consistent with either chronic granulocytic leukemia or chronic inflammation that involves a major organ or body cavity. The latter was confirmed by abdominal radiographs which revealed pyometra. The decrease in PCV is due to the anemia of inflammation.

The marked leukocyte response in this case was caused by chronic suppu- ration. This pattern is called a leukemoid reaction since the hematologic features are very similar to chronic granulocytic leukemia. Large internal abscesses, suppurative pyoderma, or suppuration of body cavities are frequent causes.

Diagnosis

Pyometra with leukemoid reaction and anemia of inflammation.

Case 18: Canine 10 Year Old Female Sheltie

History

Depression, anorexia, pot-bellied abdomen.

Physical Examination

Normal body temperature, increased pulse, pale mucous membranes, large abdominal mass, marked weight loss.

Discussion/Interpretation

A severe thrombocytopenia and normocytic normochromic anemia are present. A marked neutrophilic leukocytosis is present with a severe left shift that includes metamyelocytes and myelocytes. Toxic change was not evident but blast cells that appeared to be granulocytic precursors were detected (Fig. c18-1 and Fig. c18-2). Lymphocytes and monocytes are increased. In an intact female dog, the leukocyte pattern could be indicative of chronic inflammation as would occur in a closed pyometra. The severe anemia, thrombocytopenia, and excessive number of immature neutrophils are strong indication for bone marrow aspiration. The abdominal mass was a very large spleen. The bone marrow and spleen aspirates were diffusely infiltrated by large blast cells and developing neutrophil precursors (Fig. c18-3 and Fig. c18-4). Megakaryocytes and erythroid precursors were rare. Similar cells were detected in aspirates of lymph node. These findings confirmed a diagnosis of chronic granulocytic leukemia.

Diagnosis

Chronic granulocytic leukemia. The leukocyte pattern is similar to that which is found in dogs with extensive suppurative inflammation. However, in chronic granulocytic leukemia, a disproportionate number of immature neutrophils is often noted along with severe anemia and thrombocytopenia due to myelophthisis.

Figure c18-1. Canine blood. Marked leukocytosis due to a neutrophilia and a population of large round cells that are difficult to identify at this magnification (40x).

Figure c18-2. Canine blood. Segmented neutrophils are present but there is a disproportionate number of immature granulocytes present with indented, lobulated, or rounded nuclei. One of the larger cells is a blast form and has multiple nucleoli. RBCs are normocytic and normochromic indicating a nonre- generative anemia. Platelets are markedly reduced. These findings are consistent with chronic granulocytic leukemia (100x).

Figure c18-3. Bone marrow. The marrow is cellular and contains numerous large immature granulocytes and mature neutrophils. Erythroid and megakaryocytic precursors are rare (40x).

Figure c18-4. Bone marrow. Higher magnification reveals an abundance of blast cells that have a light blue cytoplasm, round or elongate nucleus, and prominent nucleoli. Toxic change is not apparent in either blood or bone marrow neutrophils (100x).

Case 19: Feline 4 Year Old Male DSH

History

Loss of appetite and lethargy for 3 days.

Physical Examination

T=104°F, pale mucous membranes, mild dehydration.

Discussion/Interpretation

A severe regenerative anemia is present with a slightly increased TPP. The regenerative response is orderly and proportional to the severity of anemia and is characterized by anisocytosis, macrocytosis, increased MCV, polychromasia, reticulocytosis, and metarubricytosis (Fig. c19-1). The absence of hypoproteinemia and clinical hemorrhage, and the presence of an intense regenerative response, icteric plasma, and agglutination are consistent with hemolytic anemia. Causes of hemolytic anemia include infectious agents, immune-mediated disease, toxins, fragmentation, and osmotic lysis. The identification of numerous H. felis organisms on erythrocytes (Fig. c19-2) coupled with the regenerative response confirms a diagnosis of Haemobartonellosis. These parasites initiate immune- mediated destruction of RBCs which frequently results in a positive direct Coombs' test.

Figure c19-1. Feline blood. Marked polychromasia, anisocytosis, and macrocytosis indicate regenerative anemia. Small basophilic coccoid or rod- shaped organisms are noted on the RBCs. A few ring forms with a light central area can be seen on a few RBCs. These organisms are Haemobartonella felis which causes a hemolytic anemia (100x).

Figure c19-2. Feline blood. In a thin area of the smear, the ring forms of the parasite are visible in small chains or groups on the RBC membrane (100x).

The number of organisms on the smear can change dramatically from day to day. Thus, if the parasite is suspected, repeated examinations of blood films may be necessary to make a diagnosis. Organisms may detach from erythrocytes if there is a time delay between blood collection and preparation of the blood film. Detached organisms may aggregate at the feather edge of the smear.

Case 20: Canine 9 Year Old Female Golden Retriever

History

Weakness, lethargy, weight loss for 5 weeks.

Physical Examination

Dog is alert but very weak; pale mucous membranes, enlarged liver and spleen, systolic heart murmur.

Discussion/Interpretation

The anemia is normocytic and normochromic with an absence of reticulocytosis or polychromasia (Fig. c20-1). These features indicate that the anemia is nonregenerative. The combination of severe nonre- generative anemia, thrombocytopenia, and neutropenia is called pancytopenia. The neutropenia is not accompanied by a left shift. Causes of this hematologic pattern include infectious agents, marrow injury due to toxins or drugs, immune-mediated disease, and neoplasia. Bone marrow aspiration is indicated because of the pancytopenia and the blast cells identified in the differential count (Fig. c20-1 and Fig. c20-2). The marrow aspirate was very cellular and contained a homogenous population of blast cells similar to those in blood (Fig. c20-3). These cells were very large and had dark blue cytoplasm, round or indented nuclei, and singular prominent nucleoli. Erythroid, megakaryocytic, or granulocytic precursors were rare.

Figure c20-1. Canine blood. Severe anemia, leukopenia and thrombocytopenia. The RBC are normocytic and normochromic indicating nonregenerative anemia.Several large hyperchromatic blast cells were noted and are especially obvious when compared with a neutrophil (100x).

Figure c20-2. Canine blood. Large blast cell has dark blue cytoplasm, round eccentric nucleus, multiple nucleoli, and focal cytoplasmic clear zone (100x).

Figure c20-3. Bone marrow. The marrow has been effaced by a homogeneous population of blast cells similar to those in peripheral blood. Normal marrow precursors are infrequent. Although this acute leukemia has over- populated the marrow, very few of the blast cells were noted in the CBC (100x).

Diagnosis

Acute leukemia. Spleen and liver were diffusely infiltrated with blast cells.

Case 21: Canine 2 Year Old Standard Poodle

History

Seems to be short of breath and listless. No clinical evidence of dehydration.

Physical Examination

Normal temperature, rapid pulse (110/minute), mucous membranes are brick red, congested, and sometimes cyanotic. Retinal, scleral, sublingual, and jugular veins are very large and engorged.

Discussion/Interpretation

A PCV of 78% in the absence of severe dehydration indicates an absolute polycythemia. Absolute polycythemias are classified as primary or secondary according to the cause or mechanism. Primary polycythemia is a myeloproliferative disorder or neoplasm characterized by excessive production of mature RBCs, normal arterial oxygen content, and normal or decreased erythropoietin levels. Secondary polycythemias are caused by hypoxemia which leads to increased erythropoietin levels. Secondary polycythemias can also be caused by excess production of erythropoietin in the absence of hypoxemia. The latter is quite rare and occurs with tumors, cysts, or space-occupying lesions of the kidney, liver, or adrenal. Chest radiographs of the Poodle revealed a pumpkin-shaped cardiac silhouette. Severe hypoxemia was confirmed by the arterial blood gas analysis (P02 = 32 mmHg, reference range 85-95 mmHg). Angiography revealed a large interventricular septal defect that allowed right to left shunting of blood. Hypoxemia resulted because a large portion of systemic venous blood bypassed the lungs. The reduced arterial oxygen content was detected by receptors in the kidney that initiated an increase in erythropoietin. This hormone is the primary stimulus for marrow erythroid hyperplasia (Fig. c21-1).

Figure c21-1. Bone marrow. The severe polycythemia in this dog is caused by overproduction of RBCs in the marrow. This is confirmed by the marked erythroid hyperplasia that is evident. The maturation is orderly and there is no evidence of neoplasia. Chronic hypoxemia caused increased erythropoietin secretion which resulted in polycythemia (40x).

Diagnosis

Absolute polycythemia secondary to hypoxemia due to cardiac defect.

Case 22: Canine 6 Year Old Male English Bull Dog

History

Prior history of otitis which responded to treatment. Mild anemia and increase in TPP noted at that time. Presented 3 months later with enlarged peripheral lymph nodes and decreased activity level.

Physical Examination

Weight loss and enlargement of all palpable lymph nodes; normal body temperature; no evidence of dehydration.

Discussion/Interpretation

A mild normocytic, normochromic anemia is present with no evidence of regeneration. PCVs in Bull Dogs fall in the upper end of the reference range because they are a brachycephalic breed. The absence of dehydration suggests that the hyperproteinemia is due to hyperglobulinemia. The PCV and TPP values are similar to previous measurements indicating that these changes are persistent. The leukogram suggests a stress response or mild inflammation. Atypical lymphocytes were not detected on the blood films. Basophilic background on the blood film is consistent with hyperproteinemia (Fig. c22-1). Fine needle aspiration of lymph nodes and protein electrophoresis are indicated.

Figure c22-1. Canine Blood. Marked hyperproteinemia produces a heavy blue background that highlights the cell membranes of the RBCs. RBC morphology does not reveal any evidence of regeneration. Platelets are reduced (100x).

Causes of generalized lymph node enlargement include lymphoma, systemic infection, and immune-mediated disease. The lymph node aspirate revealed a homogenous population of large lymphoblasts and confirmed a diagnosis of lymphoma. Bone marrow aspiration revealed a similar infiltrate (Fig. c22-2). A monoclonal gammopathy was evident in the serum protein electrophoresis and was responsible for the hyperproteinemia. Lymphoid neoplasms may produce very high levels of a single immunoglobulin which causes a monoclonal peak in the electrophoresis. Most dogs with lymphoma do not have significant hematologic abnormalities. The most frequent changes are mild nonre- generative anemia and a mature neutrophilia. Both changes are due to the presence of a neoplasm. An absolute lymphocytosis in canine or feline lymphoma is an infrequent occurrence.

Figure c22-2. Bone marrow. Normal granulopoietic and erythroid cells have been replaced by a population of large lymphoblasts that have singular prominent nucleoli (100x).

Diagnosis

Lymphoma with monoclonal gammopathy.

Case 23: Canine 9 Year Old Castrated Male Mixed Breed

History

Treated for anemia with hematinics for 2 weeks. Moderate weight loss. Anorexia and profound weakness for 2 days. Distended abdomen.

Physical Examination

Normal body temperature; pale mucous membranes and rapid respiration. Abdominocentesis reveals a large amount of bloody fluid. Dog is very weak and collapsed.

Discussion/Interpretation

A marked regenerative anemia is present as evidenced by anisocytosis, polychromasia, reticulocytosis, metarubricytosis, and an increase in MCV and a decrease in MCHC. Hypoproteinemia, the absence of icterus, and the abdominal hemorrhage confirm blood loss anemia of several days duration. A coagulation profile revealed a moderate increase in prothrombin time, partial thromboplastin time, and fibrin degradation products. These changes along with moderate thrombocytopenia and schistocytes (Fig. c23-3) indicate the presence of disseminated intravascular coagulation. The leukogram reveals a moderate neutrophilia, mild left shift, and monocytosis that are consistent with inflammation and tissue necrosis. Acanthocytes are numerous on the blood film (Fig. c23-1 and Fig. c23-2) and are frequently associated with hemangiosarcoma in the liver. The CBC results, history, and abdominal hemorrhage are compatible with hemangiosarcoma.

Figure c23-1. Canine blood. Anisocytosis, polychromasia, and macrocytosis indicate regenerative anemia. Marked poikilocytosis is due to the presence of numerous acanthocytes. These RBCs have irregular membrane projections that have variable lengths and rounded points. Platelet numbers are reduced (100x).

Figure c23-2. Canine blood. Numerous acanthocytes and spheroechinocytes are present. Acanthocytes in a dog with anemia and thrombocytopenia suggest that hepatic involvement with hemangiosarcoma should be considered (100x).

Figure c23-3. Canine blood. Marked thrombocytopenia and the presence of several schistocytes or fragmented RBCs are indications that thrombosis or DIC is occurring. Coagulation tests are indicated (100x).

Diagnosis

Hemorrhagic anemia and DIC with inflammatory leukogram. Exploratory surgery was done. A ruptured splenic hemangiosarcoma with numerous metastatic lesions in the liver was detected.

Case 24: Canine 9 Year Old Spayed Female Corgi

History

Bloody urine and weakness for 5 days.

Physical Examination

Mucous membranes are pale and melena is present. Numerous petechial hemorrhages. Abdomen is painful on palpation.

Discussion/Interpretation

Macrocytosis, reticulocytosis, polychromasia, metarubricytosis, and anisocytosis indicate regenerative anemia. Hypoproteinemia, hematuria, petechiation, and melena indicate that the anemia is due to hemorrhage as a result of the severe thrombocytopenia (Fig. c24-1). Hemolytic anemia is also a possibility. A neutrophilic leukocytosis with left shift and monocytosis indicate inflammation with possible tissue necrosis. Lymphopenia is due to stress. The eosinophilia if persistent is an indication of hypersensitivity. A coagulation profile (PT, PTT, FDP) was normal. Direct Coombs'; test and titers for Ehrlichia, Lyme disease, and Rocky Mountain Spotted Fever were negative.

Figure c24-1. Canine blood. Regenerative anemia and thrombocytopenia are pronounced. The large round granular structure in the center is a giant platelet. Large shreds of megakaryocyte cytoplasm are often found in severely thrombocytopenic animals (100x).

Aspiration of bone marrow is indicated to assess thrombopoiesis. The marrow was very cellular and revealed an increase in immature and mature megakaryocytes (Fig. c24-2). Erythroid hyperplasia was also noted. These findings indicate that the thrombocytopenia was due to excessive destruction rather than reduced production.

Figure c24-2. Bone marrow. Bone marrow examination is helpful in the assessment of thrombocytopenic animals. In this marrow there are numerous megakaryocytes in the field indicating that the decrease in platelets is due to accelerated destruction rather than decreased production (25x).

Diagnosis

Presumptive immune-mediated thrombocytopenia. Dog was treated successfully with predisone and azothioprine.

Case 25: Canine 11 Year Old Spayed Female Basset Hound

History

Dog presented for suture removal and recheck following a splenectomy that was done 8 days ago. Hemoperitoneum and a large splenic hematoma were noted during laparotomy. PCV at the time of surgery was 25%.

Physical Examination

Abdominal incision is healing normally. TPR is normal. Mucous membranes are pink with normal capillary refill.

Discussion/Interpretation

The leukogram is unremarkable except for a lymphopenia that is due to stress. A mild, normocytic, normochromic anemia is present with a minimal reticulocyte response. These findings indicate that the regenerative response is either inadequate or subsiding as the PCV approaches normalcy. Examination of the blood film is indicated in all anemic animals. Erythrocytes need to be examined for size, shape, color, and inclusions. Examination of the blood film revealed moderate numbers of coccoid, basophilic, epicellular RBC parasites (Fig. c25-1). Many of the organisms were arranged in chains that branched. The morphology of the organisms was consistent with Haemobartonella canis.

Figure c25-1. Canine blood. Chains of basophilic small coccoid organisms are noted on the surface of two RBCs. Haemobartonella canis causes a mild to moderate hemolytic anemia in dogs that have been splenectomized or treated with immunosuppressive drugs.

H. canis causes mild anemia due to extravascular hemolysis in dogs that have been splenectomized or in those that have received glucocorticoids, chemotherapy, or immunosuppressive drugs. The organism can be transmitted by blood transfusion or by biting arthropods. This dog received a blood transfusion during surgery and the donor was subsequently identified as an infected carrier.

Diagnosis

Mild anemia due to Haemobartonella canis. Dog was treated with tetracycline and made an uneventful recovery.

Case 26: Feline 7 Year Old Male Domestic Shorthair

 History

Owner reports that the cat drinks a lot of water and has been losing weight. Appetite is diminished.

Physical Examination

Cat is depressed, mildly dehydrated, and in poor body condition.

Discussion/Interpretation

The CBC reveals a moderate, normocytic, normochromic anemia with no evidence of regeneration. Hyperproteinemia is due to dehydration. The leukogram reveals a marked lymphopenia which can be due to stress or to loss or sequestration of lymphocytes. Examples of the latter include chylous effusions or protein-losing enteropathy. Absence of GI signs and negative chest radiograph eliminates these causes. Examination of the blood film did not reveal significant abnormalities.

A bone marrow aspirate revealed a cellular marrow with an increased M:E ratio, normal iron stores, and adequate megakaryocytes. Maturation in granulocytes and in the limited number of erythroid cells was normal. In light of the normal neutrophil count and the moderate non- regenerative anemia, the M:E ratio is increased due to decreased erythroid activity rather than increased granulopoiesis (Fig. c26-1). Causes of erythroid depression need to be considered. Serum chemistry results indicate severe azotemia (urea=205 mg/dl, creatinine=11.9 mg/dl). Isosthenuria and severe proteinuria with an inactive sediment were noted in the urinalysis. The azotemia and urine specific gravity were unaffected by fluid therapy and diuresis. These findings are consistent with chronic renal disease with severe proteinuria. The anemia is due to diminished erythropoietin production which causes decreased RBC production in the bone marrow. In the absence of a regenerative anemia or certain metabolic disorders, Heinz bodies are considered an incidental finding.

Figure c26-1. Feline bone marrow. In nonregenerative anemias, bone marrow assessment is extremely valuable in deciding the cause or mechanism. In this cat, diminished erythropoietin levels as a result of renal disease lead to erythroid hypoplasia. Therefore the M:E ratio is increased in the marrow due to a reduction in erythroid cells relative to the granulocytes (40x).

Diagnosis

Nonregenerative anemia due to chronic renal disease (renal amyloidosis).

Case 27: Canine 12 Year Old Mixed Breed Male

History

Male dog was admitted to the hospital 4 days ago for elective castration due to benign prostatic hypertrophy. There was no palpable tumor but the prostate was symmetrically enlarged and the dog was having difficulty urinating and defecating. He had previously been in excellent health and had an unremarkable medical history. He had no past history of bleeding. Surgery had been uneventful but petechiae and ecchymoses on the ventral abdomen were noted four days postoperatively.