Clinical Pathology
Kristin Canga, RVT

• Page 68 – Lab Pro book
• ‘Clinical Application’ box (Iron
Deficiency Anemia) on pg. 12 of A&P book
• Pages 55 – 57 Lab Pro book (about counting reticulocytes)

• Literally means “no blood” but clinically means an
______________ ____________________below normal in any of the following values:
– ________________________________________
– ________________________________________
– ________________________________________
• In other words, anemia is a condition of reduced oxygen carrying capacity of RBCs
– Rate of RBC ______________________ = decreased
– Rate of RBC ______________________ = increased

• A thorough ___________ must be obtained.
– This helps the doctor know: what the patient has been
____________ /____________, where they have been, how long they have been suffering, and possibly
_________ the anemia has occurred.
• A physical exam should be completed.
– Put your ____________ on the animal!
– Look for _____________, _____________,
_____________, active bleeding, elevated heart/respiratory rates, etc…
• A complete _____________evaluation is a MUST.

1. __________________________of clinical signs
– ______________ onset suggests acute
_________________ or ______________
– ______________ onset suggests chronic
______________ or bone marrow depression
2. Evidence of blood loss
– ______________
– ______________
– ______________
– Blood in ______________

3. ____________________________
4. Existence of an underlying condition or prior illness
– ____________________________
– ____________________________
– ____________________________
5. Exposure to drugs
- human ______________ , ______________
6. Exposure to toxic ______________ in the
______________
- ______________ , poisonous _________,
______________

1. ______________
– Suspect: infection, leukemia, hemorrhage, or hemolysis
2. Character of ___________________:
– ______________
– ______________ – liver disease or hemolysis
– ______________ + ______________ = hemolysis
– ______________ - hypoxia
– ______________ or ______________ = platelet or vascular defect

3. Palpation
– ______________
– ______________
– ______________
– ______________
4. ______________ signs of underlying disease
5. External wounds
– ______________
– ______________
– ______________

• Classification is to aid in discovering the _______________ and to help guide __________________.
• Remember: Anemia is not a __________________, but a sign of an underlying health concern.
• Anemia may be considered ___________________ or
________________________ and is generally classified/diagnosed in one of two different ways:
1. By RBC ________ and ____ concentration a. RBC ____________________ (MCV, MCHC)
2. By bone marrow response a. ________________________________ b. ________________________________

Initial laboratory tests to evaluate the anemic patient include (but not limited to):
1. ______________ (and color of supernatent plasma)
2. Total ______________ protein
3. Examination of ______________ and
____________________________
4. Total ______________ count
5. ______________ estimation
6. ______________ concentration
7. Total ______________ count
8. ______________ **
9. ______________ evaluation **


• What is it measuring?
• Normal ranges for dogs?
• Normal ranges for cats
• Plasma (supernatent) colors?

• What is it measuring?
• How is it measured?
• What is normal range for dogs and cats?

• As a rule, the following values should be considered:
– RBC total numbers should be in the ______________ .
(10 6 /μL)
– Plt total numbers should be in the ______________ of
______________ . (200,000 – 500,000/μL)
– WBC total numbers should be in the ______________ to
____________________________ . (6,000 – 17,000/μL)
• Neutrophils: 60 – 77%
• Lymphocytes: 12 – 30%
• Monocytes: 3 – 10%
• Eosinophils: 2 – 10%
• Basophils: rare (<2%)
In dogs and cats

• What area are you evaluating?
• How are cells arranged?
• Are RBCs normal?
• How many WBCs are counted?
• How many fields are counted for plt. estimation?
• What is calculation for plt. estimation?

• Overall count should be in ______________ to
____________________________ . (6,000-
17,000)
• Total count calculated by machine
 Manual hemacytometer is rare in clinic and diluent is no longer available.
• Increased WBCs = ______________
• Decreased WBCs = ______________

• Done by machine.
• Aids us in calculating average
______________ of RBCs (_______)
• Aids us in calculating average ______ concentration within RBCs (_______)
• Can aid in calculating average
______________ of Hb within average RBC.
(_______)
*** MCH is LEAST accurate***

• MCV: ____________________________
• MCHC: ____________________________
• MCH: ____________________________

• Hb concentration is ~_______ of PCV (in g/dL)
• Total RBCs are ~_______ of PCV (in millions)

• Recall that MCV (mean corpuscular volume) describes the average volume of the individual RBC
– Normal MCV = _____________________
– Increased MCV = _____________________
– Decreased MCV = _____________________
FORMULA: (PCV / Total RBC) X 10 = MCV (femtoliters)
Normal MCV = canine: 60 – 77 fl. feline: 40 – 55 fl.

• The MCV of a patient with a PCV of 12% is:
– Step 1: Recall the formula:
• (_______/ ______________) X 10 = MCV (femtoliters)
– Step 2: Remember the ROT
• total RBC ≅ _______ PCV so:
• ______________ = ______________
– Step 3: plug in the numbers
• ___________________________________
• Is this normal for k9/fel?
• How would you classify this RBC?

• Possible causes of Increased MCV:
– Increased _____________________activity = #1
• Reticulocytosis
– Congenital (___________&_________________)
– Cats with _______ (+/- anemia)
• Possible causes of Decreased MCV:
– ______________ deficiency = #1
– Congenital disorder (_______and ______________)

• MCHC (mean corpuscular hemoglobin concentration):
– Describes the ratio of the _______of hemoglobin to the ______________in which it is contained
(concentration of hemoglobin in the avg. RBC)
– Normal MCHC = ______________
– Decreased MCHC = ______________
– High MCHCs = artifact WHY???

(______ / ______) X ______= MCHC (g/dL)
Normal MCHC = canine: ______________g/dL feline: ______________g/dL
• Remember the ROTs?
• If you calculate MCHC by estimating Hb, the values will always come out the same.
• Lets do the math!

• The MCHC of a patient with a PCV of 33% is:
– Step 1: Recall the formula
• (_______ / _______) X _______= MCHC (g/dL)
– Step 2: Remember the ROT
• Hb ≅ _______ of PCV so:
• _______= _______
• Step 3: Plug in the numbers
• __________________________________________

• The patient’s Hb is 9g/dL, and their PCV is 30%
• Formula: (_______/_______) x _______
• SO: _______________________=_____g/dL
• Is this normal for k9? Fel?
• How would it classify the RBC?

• Severe _______deficiency
• Marked, regenerative anemia
– ____________________________RBCs that do not yet have their full complement of Hb.
MCHC increase:
• Presence of ______________, ______________, and ___________ can interfere with tests and
______________increase MCHC
• True _____________________anemia cannot exist; the erythrocyte cannot be oversaturated with ______.

MCV normal
MCHC normal
Normocytic
Normochromic
MCHC decreased
Normocytic
Hypochromic
MCV increased
MCV decreased
Macrocytic
Normochromic
Microcytic
Normochromic
Macrocytic
Hypochromic
Microcytic
Hyprochromic

Normocytic ; Normochromic
Macrocytic Microcytic Hyperchromic Hypochromic

• You will need to know HOW to do this for VTNE, even though it is the _______accurate of the indices.
• Calculates the average _______of Hb contained in average RBC.
• (_______/_______) x _______= MCH in picograms (pg)
– Normal ranges:
• K9: _______pg
• Fel: _______pg

• The MCH of a patient with a PCV of 54% is:
• Step 1: Remember the formula
– (_______/_______) x _______= MCH
• Step 2: Remember the ROT
– Hb ≅ _______ PCV and RBCs ≅ _______ PCV
• _______ = _______ and _______ = _______
• Step 3
– Plug in the numbers:
• _____________________pg

• Most applicable way to differentiate between:
– ________________________ and
________________________ anemia

Regenerative anemia
– Characterized by evidence of increased ______________ and delivery of new erythrocytes into ______________
(usually within 2-4 days).
– Usually suggests bone marrow is responding appropriately to either:
• _____________________ (acute or chronic; internal or external) or
• _____________________ (intravascular or extravascular)
– Involves determining whether absolute
_____________________ numbers are increased in the blood.

Non-regenerative anemia
– Lack of circulating ______________ RBCs in the face of _______ indicates a nonregenerative anemia and likely results from bone marrow ______________.
• Either reduced erythropoiesis or defective erythropoiesis
– No response evident in ______________blood.
(usually ______________; ______________)
– _____________________examination may be helpful with the diagnosis.

1. Blood Loss Anemia
Acute _____________________– relatively large amount of blood lost in a brief period. (______________;
______________)
– PCV initially = ______________
– Reticulocytes should appear ~_______ hrs (peak within ~ 1 week)
– Causes: a. ______________
– Internal or external
– Accidental or surgical b. ______________disorders c. Bleeding ______________ or large ______________

Chronic blood loss (_______Deficiency Anemia) – lost
______________and ______________for a period of time.
a. Parasites
– ______________, _______, blood-sucking _______, coccidia spp.
b. GI ulcers and neoplasms c. Inflammatory bowel disease d. Overuse of ______________donors
• Note: neonates can become iron deficient due to lack of adequate dietary _______ intake.

• Body compensates for anemia by lowering _______-
_______ affinity, preferential shunting of blood to vital
_______, increased ______________output (tachycardia), and increased levels of _____________________.
• With decreasing _______ stores, erythropoiesis is limited and RBC’s become ______________and deficient in
_______ (______________and _____________________).
– Hallmark of iron deficiency anemia is decreased _______.
• Keratocytes & schistocytes
• Clinical signs include: lethargy, weakness, decrease exercise tolerance, anorexia, lack of grooming, mild systolic murmur .

• 2. _____________________: increased rate of erythrocyte _______________________ within the body.
a. Immune-mediated
-_____________________
-_____________________
- Incompatible _____________________ a. Blood Parasites
-Hemotrophic Mycoplasmas
- ______________________spp.
- ________________________

c. Heinz body anemia
– Plants
• Onions*, garlic
– ______________________
– Drugs or Chemicals
• ( ______________________ , Propylene glycol, Zinc,
Copper, Methylene blue, Naphthalene,
______________________ , phenothiazine, benzocaine
– Diseases (in cats)
• Diabetes mellitus
• Hyperthyroidism
• Lymphoma

d. ______________________ induced hemolysis
RBC glycolysis is inhibited by hypophosphatemia; no glycolysis = no ATP (energy) for RBC = cell lysis
• Diabetic cats
• Enteral alimentation

e. Other Microorganisms
– ______________________
• Clostridium spp. and Leptospirosis (cattle)
– ______________________
• ______________________ f. ______________________ intoxication (usually calves)
– can also occur as a result of inappropriate administration of
______________________ therapy.
g. ______________________ RBC defects
– ______________________ (shortened RBC lifespan)
– RBC membrane transport defects
– Chronic intermittent hemolytic anemia (Abyssinian and
Somali cats)

h. Miscellaneous
– Metabolic disorders (anything that interferes with synthesis of ______________________ , RBC, etc. or anything that interferes with
______________________ processes of RBC)

• Most non-regenerative anemias are
______________________
• Further sub-classified based on whether
______________________ (neutrophil production) and ______________________
(platelet production) are also affected.
• Animals with non-regenerative anemia in conjunction with ______________________
(neutropenia and thrombocytopenia) usually have
____________ cell injury.
– Possible causes: drugs, toxins, viruses (FeLV), radiation, and immune-mediated stem cell injury.

1. Reduced ______________________ a. Chronic ______________________ disease b. Endocrine deficiencies c. Inflammation and neoplasia d. Cytotoxic damage to the
______________________
• Estrogen toxicity
• Cytotoxic cancer drug therapy
• Chlormphenicol (cats)
• Radiation
• Other drugs

e. Infectious agents
– FeLV
– ______________________ spp.
– ______________________ f. Immune-mediated
– Continued treatment with recombinant erythropoietin
– ______________________ aplastic anemia g. Congenital/inherited h. ______________________ and other
______________________ disorders

2. Defective ______________________ a. Disorders of ___________ synthesis
– Iron, copper, and pyridoxine deficiencies; lead toxicity; drugs b. Folate and ____________ deficiencies c. Abnormal ______________________
• can be inherited, drug-induced or idiopathic

• Probably the most important diagnostic tool used in the evaluation of anemia.
• Fewer _____________ erythrocytes are present in anemic animal; more
______________________ are present.
• Expressed as a _____ of the RBCs present.
• The lifespan of a normal RBC is about 110 days
(dogs) and 68 days (cats).
– Bone marrow should replace ___ % of the RBCs daily so the reticulocyte count should be _____-______%.

1. Gently mix 4 drops of blood with 4 drops of new methylene blue in a test tube.
2. Let mixture stand for 15 minutes
3. Use 1 drop of mixture to prepare a diagnostic blood film and observe under high-power, oilimmersion field.
4. Count 1,000 RBCs while separately keeping track of the number of reticulocytes (only aggregate form)
5. Divide the reticulocyte number by 1,000 and convert to a percentage. (Multiply by 100)

• If you see 10 retics on slide 1 and 15 on slide
2, your total is 25 reticulocytes.
• 25/1000 = 0.025 x 100 = 2.5%

• Performed to take in account the reduced number of circulating
RBC’s in the anemic animal.
– Called CRC or Corrected Reticulocyte Count
– FORMULA:
• Observed retics % x PCV / normal PCV
• (Normal PCV: use 45% for dogs and 35% for cats)
Ex: 2.5% X 30% / 45% = 1.67%
Note: This calculation is necessary because the reticulocyte count is misleading in anemic patients. The problem occurs because the reticulocyte count is not really a count but rather a percentage : it reports the number of reticulocytes as a percentage of the number of red blood cells. In anemia, the patient's red blood cells are reduced, creating an elevated reticulocyte count.