Hematocrit (HCT)
| Units | Canine | Feline | Equine | Bovine | Alpaca | Caprine | |
| HCT | % | 41 – 58 | 31 – 48 | 34 – 46 | 25 – 33 | 26 – 45 | 28 – 44 |
| Increased | |
| Artifact | False increases in MCV (HCT is a calculated value): Uptake of water with storage (delayed processing) or hyper-osmolality (hypernatremia, hyperglycemia etc), agglutination |
| Relative change to blood water | Dehydration (common), splenic contraction (horses particularly) |
| Absolute ↑ in RBC mass | Primary polycythemia (polycythemia vera or chronic erythroid leukemia, rare), secondary polycythemia due to appropriate secretion of erythropoietin (hypoxia) or inappropriate secretion of erythropoietin (renal cysts/neoplasia, other neoplasia) |
| Decreased | |
| Artifact | Hemolysis (in vitro), false decreases in MCV (excess EDTA – common, hyponatremia) |
| Relative change to blood water | IV fluid dilution, splenic relaxation (anesthetic agents, tranquilizers) |
| Absolute ↓ in RBC mass | Anemia – Hemorrhage, hemolysis, ↓ production |
RBC
| Units | Canine | Feline | Equine | Bovine | Alpaca | Caprine | |
| RBC | x 106/μL | 5.7 – 8.5 | 6.9 – 10.1 | 6.6 – 9.7 | 5.0 – 7.2 | 10.6 – 18.4 | 13.6 – 23.7 |
| Increased | |
| Artifact | Thrombocytosis with large platelets (marked, rare) |
| Relative change to blood water | Dehydration (common), splenic contraction (horses particularly) |
| Absolute ↑ in RBC mass | Primary polycythemia (polycythemia vera or chronic erythroid leukemia, rare), secondary polycythemia due to appropriate secretion of erythropoietin (hypoxia) or inappropriate secretion of erythropoietin (renal cysts/neoplasia, other neoplasia) |
| Decreased | |
| Artifact | Hemolysis (in vitro), clotting of sample, agglutination |
| Relative change to blood water | IV fluid dilution, splenic relaxation (anesthetic agents, tranquilizers) |
| Absolute ↓ in RBC mass | Anemia – Hemorrhage, hemolysis, ↓ production |
Hemoglobin
| Units | Canine | Feline | Equine | Bovine | Alpaca | Caprine | |
| Hgb | g/dL | 14.1 – 20.1 | 10.9 – 15.7 | 11.8 – 15.9 | 8.7 – 12.4 | 11 – 19.3 | 8.9 – 13.8 |
| Increased | |
| Artifact | Lipemia (common), Heinz bodies, nRBC |
| Iatrogenic | Oxyglobin therapy |
| Relative change to blood water | Dehydration (common), splenic contraction (horses particularly) |
| Absolute ↓ in RBC mass | Anemia – Hemorrhage, hemolysis, ↓ production |
| Decreased | |
| Relative change to blood water | IV fluid dilution, splenic relaxation (anesthetic agents, tranquilizers) |
| Absolute ↓ in RBC mass | Anemia – Hemorrhage, hemolysis, ↓ production |
Mean Cell Volume (MCV)
| Units | Canine | Feline | Equine | Bovine | Alpaca | Caprine | |
| MCV | fL | 64 – 76 | 40 – 52 | 43 – 55 | 38 – 51 | 22 – 28 | 16 – 22 |
| Increased | |
| Artifact | RBC clumping or agglutination, storage-changes (swelling – common), hyperosmolality (e.g. hypernatremia) |
| Physiologic | Breed (Greyhounds, Miniature and Toy Poodles), fetal RBC |
| Anemia | Regenerative anemia (immature RBCs can have bigger volumes, but not always) |
| Osmotic/membrane abnormailities | Hereditary stomatocytosis (e.g. Alaskan Malamutes, Miniature Schnauzers, Pomeranians, Drentsche Patrijshond) |
| Defects in nuclear maturation/DNA synthesis | Primary myelodysplasia, folate and Vitamin B12 deficiency (both uncommon), hydroxyurea (interference with DNA metabolism) |
| Inherited abnormalities in erythropoiesis | Congenital dyserythropoietic anemia (Polled Hereford cattle, Poodles) – uncommon |
| Idiopathic | Hyperthyroidism (reported in some cats) |
| Decreased | |
| Artifact | Excess EDTA (common), hyponatremia |
| Physiologic | Age (puppies, kittens, foals, calves), breed (Akitas, Shiba Inu, Shar Pei, Siberian Husky) |
| Iatrogenic | Chloramphenicol, lead (secondary iron deficiency) |
| Iron deficiency | Iron deficiency, nutritional deficiency (copper, pyridoxine), excess zinc (interferes with iron absorption) |
| Hepatic dysfucntion | Portosystemic shunts |
| Idiopathic | Inherited dyserythropoietic disorder in English Springer Spaniels (rare) |
MCHC
| Units | Canine | Feline | Equine | Bovine | Alpaca | Caprine | |
| MCHC (Mean corpuscular hemoglobin concentration) |
g/dL | 33-36 | 32 – 35 | 34 – 37 | 34 – 38 | 42 – 49 | 32 – 34 |
| Increased | |
| Artifact | Lipemia (common), Heinz bodies (uncommon), hemolysis (in vitro or in vivo), oxyhemoglobin, nRBC (uncommon), agglutination, excess EDTA (common) |
| Decreased | |
| Artifact | RBC swelling with storage (common), hyperosmolality (e.g. hypernatremia) |
| Anemia | Regenerative anemia (normal or high MCV), iron deficiency anemia (low MCV) |
| Functional iron deficiency | Portosystemic shunts (low MCV) |
| ↓ Hemoglobin production | Lead poisoning, vitamin B6 deficiency, copper deficiency (all uncommon causes) |
| RBC swelling | Hereditary stomatocytosis |
RDW
| Units | Canine | Feline | Equine | Bovine | Alpaca | Caprine | |
| RDW (RBC distribution width) |
% | 10.6 – 14.3 | 13.2 – 17.5 | 16.3 – 19.3 | 15.0 – 19.4 | ND | 17.8 – 24.4 |
An index of the variation in cell volume within the red blood cell population. Will be increased if there are increased numbers of smaller or bigger RBC (see MCV for causes of smaller and larger RBC). A low RDW is not a meaningful finding.
nRBC
| Units | Canine | Feline | Equine | Bovine | Alpaca | Caprine | |
| nRBC | /100 WBC | 0-1 | 0-1 | 0 | 0 | 0 – 3 | 0 |
| Increased | |
| Physiologic | Species – camelids, dogs (Miniature Schnauzers, Dachshunds), premature neonates/fetuses |
| Bone marrow injury | Sepsis, heat stroke (dogs), endotoxemia (mainly cats and llamas); horses – rare |
| Dyserythropoeisis | Hereditary macrocytosis (Miniature and Toy Poodles); neoplasia (acute myeloid leukemia, myelodysplastic syndrome) |
| Splenic dysfunction | Splenic hemangiosarcoma, exogenous corticosteroids, post-splenectomy |
| Idiopathic | Heat stroke (dogs) |
| Toxins | Lead toxicosis (calves) |
Reticulocytes
| Units | Canine | Feline | Equine | Bovine | Alpaca | Caprine | |
| Reticulocytes | % | 0.2 – 1.5 | 0.1 – 0.7 | ND | ND | ND | ND |
| x 109/L | 11 – 92 | 9-61 | ND | ND | ND | ND |
These are immature anucleated RBC and are quantified as part of the regenerative response. This is primarily done for dogs and cats. In general, the absolute reticulocyte count is used to assess if an anemia is regenerative or not. For more information, see assessment of regeneration.
| Increased | |
| Normal | Dogs with mid to high normal hematocrit (>45%) |
| ↑ erythropoeisis | Regenerative anemia (Hemorrhage or hemolysis), lead poisoning (may be due to erythropoiesis or increased release), compensated hemolytic anemia (non-anemic animals), absolute polycythemia (primary or secondary – non-anemic animals) |
| Within reference intervals or decreased | |
| Normal | Dogs and cats with hematocrits in the reference interval |
| ↓ erythropoeisis | In anemic animals indicates a non-regenerative anemia or decreased/defective bone marrow production: Suppression from extramedullary disease (e.g. inflammatory disease), lack of erythropoietin (e.g. chronic renal disease), bone marrow disease (many causes) |
WBC
| Units | Canine | Feline | Equine | Bovine | Alpaca | Caprine | |
| WBC | x103/µL | 5.7 – 14.2 | 5.1 – 16.2 | 5.2 – 10.1 | 5.9 – 14.0 | 7.1 – 18.6 | 7.2 – 17.7 |
An increased or decreased WBC can be from many causes. It is more useful to look at the nature of the increased or decreased WBC, i.e. the specific leukocytes that are increased or decreased rather than the WBC in isolation.
Neutrophils
| Units | Canine | Feline | Equine | Bovine | Alpaca | Caprine | |
| Neutrophils | x103/µL | 2.7 – 9.4 | 2.3 – 11.6 | 2.7 – 6.6 | 1.8 – 7.2 | 3.5 – 11.7 | 1.9 – 9.5 |
Most common: Corticosteroids (stress), epinephrine (physiologic) and inflammation
| Increased | |
| Marginating → circulating pool | Physiologic neutrophilia (catecholamines), stress neutrophilia (corticosteroids) |
| ↑ Bone marrow release | Inflammatory cytokines |
| ↑ Bone marrow production | Granulopoiesis – many causes |
| ↓ Tissue migration | Bovine/canine leukocyte adhesion deficiency |
| Delayed apoptosis | Corticosteroids, inflammation |
| Decreased | |
| Physiologic | Dog breeds (Tervuren Shepherds, Australian Shepherds, Labrador Retrievers) |
| Circulating → marginating pool | Acute endotoxemia |
| ↓ Bone marrow release | Myelokathexis (not reported in animals) |
| ↓ Bone marrow production | Bone marrow aplasia, ineffective myelopoiesis (immune-mediated, infectious agents, drugs, histiocytic disorders), myelophthisis (leukemia, lymphoma, histiocytic sarcoma), drug-induced injury, cyclic hematopoiesis in grey collies; infectious agents (FIV, FeLV, Ehrlichia canis) |
| ↑ Tissue migration | Bacterial sepsis, tumor necrosis, abscess, endotoxemia |
| ↑ Destruction | Immune-mediated neutropenia, hemophagocytic syndromes, histiocytic sarcoma, drugs (chemotherapeutic agents), toxins and viruses (e.g. canine parvovirus, feline panleukopenia, bovine virus diarrhea) |
| Idiopathic | Vitamin B12 deficiency/”Imersland-Gräsbeck syndrome” (Border Collies, Giant Schnauzers), idiopathic neutropenia (cats) |
Band neutrophils
| Units | Canine | Feline | Equine | Bovine | Alpaca | Caprine | |
| Band neutrophils | x103/µL | 0 – 0.1 | 0 – 0.1 | 0 | 0 | 0 | 0 – 0.1 |
Increases in band neutrophils indicate inflammation and is usually, but not always, accompanied by toxic change in neutrophils.
| Increased | |
| Inflammation | Usually acute or ongoing, higher numbers are seen with more severe inflammation, left shift can include earlier precursors (e.g. metamyelocytes or myelocytes) when inflammation is severe. |
| Neoplasia | Myeloid leukemia (acute or chronic), may be accompanied by dysplasia |
Lymphocytes
| Units | Canine | Feline | Equine | Bovine | Alpaca | Caprine | |
| Lymphocytes | x103/µL | 0.9 – 4.7 | 0.9 – 6 | 1.2 – 4.9 | 1.7 – 7.5 | 1.1 – 5.5 | 2.6 – 11.7 |
Most common cause is physiologic or age-related lymphocytosis. In adult animals, should consider chronic lymphoid leukemia or leukemic phase of small or intermediate lymphoma. Antigenic stimulation can also result in a lymphocytosis in adult animals but is less common.
| Increased | |
| Physiologic | Age (< 6mths – puppies, kittens, foals); catecholamine-induced shift of lymphocytes (epinephrine response, particularly in cats, horses, young animals) |
| Antigenic stimulation | Infectious: Ehrlichia canis, bovine leukemia virus, bovine leukemia virus induced persistent lymphocytosis, feline leukemia virus, Theileria, Babesia Chronic inflammation: Inflammatory bowel disease, cholangiohepatitis |
| Neoplasia | Lymphoid leukemia, lymphoma, , thymoma |
| Other | Hypoadrenocorticism |
| Decreased | |
| Most common | Endogenous/exogenous corticosteroids, acute bacterial/viral infection |
| Iatrogenic | Glucocorticoid therapy, immunosuppressive drugs, radiation therapy, adrenocorticotropic hormone administration |
| Stress response | Endogenous/exogenous corticosteroids, hyperadrenocorticism |
| Acute inflammation | Endotoxemia, bacterial, viral infection |
| Loss of lymphocytes | Lymphocyte-rich effusions (e.g. chylothorax), loss of lymph (e.g. lymphagiectasia) |
| Lymphocytolysis | Viral infection, corticosteroids |
| Immunodeficiency | FIV, FeLV Severe combined immunodeficiency: horses (Arabian, Appaloosa), dogs (Welsh Corgi, Jack Russell Terrier, Basset Hound); Bovine hereditary zinc deficiency (lethal trait A46) |
Monocytes
| Units | Canine | Feline | Equine | Bovine | Alpaca | Caprine | |
| Monocytes | x103/µL | 0.1 – 1.3 | 0 – 0.7 | 0 – 0.6 | 0 – 0.9 | 0 – 1.0 | 0 – 0.9 |
| Increased | |
| Iatrogenic | Glucocorticoids, ACTH, granulocyte colony stimulating factor (G-CSF) administration |
| Stress response | Endogenous/exogenous corticosteroids (dogs, cats), ACTH administration, hyperadrenocorticism |
| Inflammation | Infectious: acute and chronic bacterial (e.g. Mycobacterium, Nocardia, Actinomyces), rickettsial infections, fungal (histoplasmosis, blastomycosis, cryptococcosis, coccidioidomycosis, aspergillosis), protozoal infections Necrosis: hemorrhage, hemolysis, infarction Immune-mediated hemolytic anemia |
| Paraneoplastic response | Lymphoma |
| Neoplasia | Acute and chronic monocytic leukemia, acute myelomonocytic leukemia |
| Decreased |
Eosinophils
| Units | Canine | Feline | Equine | Bovine | Alpaca | Caprine | |
| Eosinophils | x103/µL | 0.1 – 2.1 | 0.1 – 1.8 | 0 – 1.2 | 0 – 1.3 | 0.1 – 4.3 | 0 – 0.8 |
| Increased | |
| Physiologic | Estrus, pregnancy (dog) |
| Inflammation | Parasites – endoparasites (e.g. Aleurostrongylosis, Dilofilariasis), ectoparasites ; eosinophilic granuloma complex, eosinophilic inflammatory bowel disease (cats); eosinophilic myositis, eosinophilic panosteitis, eosinophilic gastroenteritis (dogs) |
| Immune-mediated | Allergic and hypersensitivity reaction (common) |
| Neoplasia | Paraneoplastic eosinophilia (mast cell tumors, lymphoma, squamous cell carcinoma); chronic eosinophilic leukemia (rare) |
| Other | Hypoadrenocorticism |
| Idiopathic | Idiopathic hypereosinophilic syndrome (Rottweilers, cats) |
| Decreased | |
| Iatrogenic | Exogenous corticosteroids |
| Stress leukogram | Endogenous corticosteroids |
Basophils
| Units | Canine | Feline | Equine | Bovine | Alpaca | Caprine | |
| Basophils | x103/µL | 0 – 0.1 | 0 – 0.2 | 0 – 0.2 | 0 – 0.3 | 0 – 0.4 | 0 – 0.3 |
| Increased | |
| Immune-mediated (accompanies eosinophilia) |
Allergies; parasites: fleas, ticks, gastrointestinal parasites, vascular parasites (e.g. Dirofilaria immitis and Dipetalonema reconditum) |
| Neoplasia | Mast cell tumors, chronic myeloproliferative disease (chronic myeloid leukemia), essential thrombocythemia (chronic platelet leukemia), basophilic leukemia (rare) |
| Decreased | |
| Urticaria and anaphylaxis, some inflammatory and immunologic conditions, corticosteroid administration, neoplasia, and hemorrhage. |
Platelets
| Units | Canine | Feline | Equine | Bovine | Alpaca | Caprine | |
| Platelets | x 103/μL | 186 – 545 | 195 – 624 | 94 – 232 | 252 – 724 | 220 – 817 | 247 – 912 |
| Increased | |
| Reactive thrombocytosis | Neoplasia, chronic inflammatory diseases, immune-mediated disease (immune-mediated hemolytic anemia, non-regenerative immune-mediated anemia), trauma (fractures, diaphragmatic hernia), drugs (especially antineoplastic agents and corticosteroids), iron deficiency anemia, splenic contraction (horses), splenectomized animals (transient) |
| Neoplastic thrombocytosis |
| Decreased | |
| Artifact | Clumping, venipuncture difficulties |
| Iatrogenic | Hemodilution |
| ↓ Production | Infection (Ehrlichia, FIV) |
| ↑ Consumption | Hemorrhage, DIC |
| ↑ Destruction/clearance | Immune-mediated thrombocytopenia |
| Loss | |
| Sequestration | Hypersplenism |
MPV
| Units | Canine | Feline | Equine | Bovine | Alpaca | Caprine | |
| MPV | fL | 8.4 – 14.1 | 9.1 – 24.3 | 5.3 – 8.4 | 5.7 – 8.0 | 4.4 – 6.9 | 5.3 – 9.4 |
Total Protein-Ref
| Total Protein-Ref. | g/dL | 5.9 – 7.8 | 5.9 – 7.5 | 5.2 – 7.8 | 5.9 – 8.1 | 6.0 – 7.5 | ND |
