CVM recognizes that readers of this Risk Assessment will have diverse training and expertise, and not all will be familiar with the practice of veterinary medicine. The purpose of this Appendix is to (1) acquaint readers with a process used by veterinarians (and specifically veterinarians working with livestock) as part of the evaluation of the health of an animal, and (2) how we interpreted veterinary examination reports on animal clones as part of the evaluation of the overall risk assessment process. It is not intended to be a guidance for veterinarians working with animal clones or any other livestock.
A. Introduction to the Comprehensive Veterinary Examination
The standard veterinary procedure that forms the basis of the CVE is referred to as the “Problem Oriented Medical Approach (POM).” Traditionally, this approach involves a Chief Complaint followed by a Physical Exam, which then generates a Problem List. The veterinarian then develops a list of Differential Diagnoses (probable causes), from which a Diagnostic Plan is formulated, including the conduct and interpretation of laboratory work. This leads to a revised Problem List based on laboratory data that implicate particular diseases or conditions. The new information results in a revised Differential Diagnosis and revised Diagnostic Plan (if additional work is still needed). All of the data finally results in a Therapeutic Plan. The owner of the animal is then informed by a Client Education Plan (Weed 1970).
Comprehensive veterinary examinations (CVEs) are systematic approaches for examining domestic livestock animals, and making informed judgments as to their health. The CVE contains both objective and subjective information, and requires experienced veterinarians familiar with the animal breeds and species to be evaluated. For each breed and species, the veterinarian is able to judge whether any observation is “normal” within the range of biologic variability. The POM is the standard medical examination and evaluation technique. This approach compares the non-healthy patient to the clinically normal animal. Each abnormal observation is recorded in a “problem list.” The veterinarian ultimately refines and compiles the problem list to develop a list of differential diagnoses that would account for the problems found on the exam. The notion of “normal” is difficult to define and articulate, and, of necessity, requires subjective assessment and expert judgment. In contrast, measurements such as temperature, pulse, respiratory rate, weight, height, etc., are objective and, in principle, easier to define as “within normal range.” Experienced examiners will agree that published “normal ranges” of these values can be slightly exceeded without judging the animal to be unhealthy. The CVE, by an experienced practitioner, employs both objective and subjective information to maximize the information gathered in examinations.
B. The Importance of Species-Specific Standards
As the purpose of this Appendix is to provide an overview of the CVE, it will not explicitly address every difference among the four species under consideration in this Risk Assessment. This Appendix will discuss the general approaches that are employed in performing such examinations. Species differ in, among other things, size, shape, demeanor, physiology, nutritional needs, and husbandry. Because of this, cows are examined differently from swine, goats, or sheep. For example, an experienced veterinarian or animal handler would not approach a dairy cow by moving toward her head first. Dairy cows are accustomed to being approached from the rear because that is how they are approached when they are milked. Other species-specific differences may be physiologically determined (e.g., birth weight ranges, reproductive behavior, gestation length) or as the result of species- or breed-specific husbandry (e.g., age of weaning, handling, and feeding practices). Thus, comparing the birth weight of Holstein and Longhorn calves would be inappropriate, as is comparing piglet weaning weights in facilities that wean at different ages.
C. How a Veterinarian Performs a Comprehensive Veterinary Examination
The physical examination portion of a CVE for any age of animal usually begins with an observation from a distance, so as not to influence the animal’s response. An animal approached by a human who is not normally involved in the animal’s care can affect its demeanor and respiratory rate. First, the consulting veterinarian observes the animal’s behavior and general appearance from a distance far enough not to provoke anxiety. The veterinarian notes the animal’s posture, resting respiratory rate, vocalizations, eating/cud chewing, excretory functions (defecation/feces and urination), gait, body condition, conformation, and general skin and coat appearance.
The subsequent close examination occurs in a systematic fashion. A CVE is generally carried out in anatomical order, usually from head to tail (except for dairy cows). If any abnormalities are discovered during the course of the examination, they are listed by functional systems, which include
- Special senses (eyes, ears, nose, mouth)
- Skin and Coat
- Musculo/Skeletal (including a body condition score)
- Peripheral Lymph Nodes.
Often, the veterinarian begins with inserting a thermometer in the rectum to measure body temperature, and, if appropriate for the species, takes a peripheral pulse in the tail (sheep with docked tails are the exception). The veterinarian then begins the examination at the head. The eyes, ears, mouth, and nose are examined. Hydration, anemia status, and other physiological measures can be assessed by examining mucous membrane color, feeling the gums for moistness, and pinching the skin to look for tenting, a sign of dehydration. The veterinarian then looks at the eyes to determine the degree to which they may be sunken from possible dehydration, whether there is any yellow coloration (jaundice from liver dysfunction), abnormal odors or discharges, whether the pupils are of similar size and symmetry (neurological function), and may perform a retinal fundic exam. While working on the head, the veterinarian can look at, smell, and touch the mouth, teeth, tongue, gums, lips, ear position, eyelid position, nostril flaring, feel for muscle atrophy, even breath from the nostrils, tongue tone, and look for drooling (ptyalism). The veterinarian then proceeds to the neck, where s/he looks, listens (auscults) and feels (palpates) for lumps, enlarged lymph nodes, salivary gland abnormalities, larynx, changes in the size or symmetry of the thyroid gland or trachea, the strength and regularity of the jugular pulse, and abnormal tracheal and pharyngeal sounds.
The next area examined is the thorax. The veterinarian observes respiratory excursions more carefully than from the initial distance overview, and notes abnormalities such as abdominal breathing or forced expirations. The veterinarian auscults (listens with a stethoscope) the heart and lungs and listens for signs of thoracic disease. Some veterinarians choose to look at the front legs and feet at this time and note any skin, musculoskeletal, hoof, or other lesions. Another approach is to look at all four legs and gait separately as its own system.
The abdomen of the animal is examined by auscultation and palpation. In ruminants, for example, the veterinarian watches the left side of the animal’s abdomen for rumen movements; these are related to cud chewing. S/he then listens to the left side of the abdomen to hear the rumen moving, and palpates the prefemoral and prescapular lymph nodes. Peritonitis (in cows) is investigated by pinching the withers to see if the cow buckles down or lordoses (arches downward) her spine. If lordosis is not observed, the animal may have peritonitis caused by hardware disease (traumatic reticulo-pericarditis, usually caused by accidental ingestion of nails or wire). In addition, while on the left side, the veterinarian pushes in on the rumen to determine fill and consistency, uses a stethoscope to listen for “normal” borborygmi (intestinal sounds), and thumps on the cow’s side to determine whether a displaced abomasum is present by listening for the characteristic pinging sound of the displacement. While examining the abdomen, s/he also has access to the umbilicus, the udder (females), prepuce (males), tail, perineum, escutcheon, and back legs. The right side of the abdomen is examined similar to the left. Pings on the right have different meanings than those on the left in all species. Lymph nodes are palpated on the right as well. The abdomen may be balloted (punched to feel for a wave of fluid). In smaller ruminants and pigs, the veterinarian palpates the abdomen by placing her/his hands behind the rib cage and pushing in and up (toward the spine) to feel for any abnormal viscera and for a gravid uterus.
In mature female animals, the veterinarian checks the mammary glands for symmetry, temperature fluctuations, swelling, or pain. The veterinarian then examines the teats at their distal end for streak canal abnormalities. Next s/he examines the milk for abnormalities such as watery or clumpy consistency, clotting, an off-color or odor, or the presence of blood. The mammary lymph nodes are examined.
External genitalia are also examined as part of the CVE (additional examinations are required for Breeding Soundness Examinations), including the vulva, prepuce, scrotum and testicles. Internal female and male genitalia are examined during rectal palpation.
If the limbs had not been examined during the thoracic and abdominal exam, they would be examined next. Skin, hoof, conformation, swollen or hot joints, sore ligaments, and lameness (gait abnormalities) are evaluated.
As ancillary tests, the veterinarian may elect to perform rectal palpation for gastrointestinal, genitourinary, cardiovascular, renal, lymph nodes, and musculoskeletal abnormalities.
Specific Considerations for Neonatal CVEs
Practitioners generally recommend examining calves, piglets, kids, and lambs within a few hours of birth for general demeanor including alertness, ability to stand, ability to suckle, respiratory excursions, mobility, etc. The neonate is then examined for cleft palate, naval abnormalities, and joint and limb abnormalities, and their chests are ausculted for cardiac abnormalities. Body temperature is also measured. Non-patent anus, or atresia ani may be discovered. Pigs, specifically, are examined for umbilical or inguinal hernias.
The newborn animals are weighed, and those measurements entered into a birth weight database used to calculate Expected Progeny Differences (EPD), especially in beef cattle. (Cattle producers use these real data to improve their herds.) Birth weights also determine “calving ease” for the dams. Passive transfer of immunity from colostrum is measured by taking blood samples and measuring IgG and total protein at approximately 24 hours post partum after the calf has had an opportunity to consume colostrum.
Specific Considerations for Juvenile CVEs
In addition to the general physical exam information on weaning weight, age at weaning, and weight gain is often collected. The producer often keeps health records, which may include sick days, diagnoses, therapeutic records, laboratory data, etc. In particular, animals may be monitored for infections at the navel, in the joints, lungs (pneumonia), and gastrointestinal system (diarrhea).
3. Specific Considerations for Mature Animal CVEs
Most cattle, swine, sheep, and goats do not live out their natural lifespans in commercial production facilities. Thus, for utility in assessing health of the animal prior to use, producers may perform formal CVEs as close to the animal’s final use (e.g., slaughter) as possible, although health records may be maintained by producers for as long as the animal is alive. Health records include illnesses, therapies, growth, weight gain, and might also include feed efficiency (for meat animals), milk production, reproductive records, and dry matter intake in dairy cows, among others.
Specific Consideration for Reproductive Stage Examinations
Breeding Soundness Examinations (BSEs) have been developed and standardized by many professional societies and graduate veterinary schools. Among others, the Society of Theriogenology has a standardized protocol for bulls (http://www.therio.org/). Its utility in comparison with others has been reviewed by Higdon et al. (2000). Shipley (1999) and Levis at the Ohio Pork Industry Center of the Ohio State University Extension (http://porkinfo.osu.edu/levis.html#Top) have published guides for evaluating reproductive performance in boars (intact male pigs). Breeding soundness exams have been developed for the small ruminants (e.g., rams and bucks) and can be found at web sites of the Utah State University Extension and the University of Minnesota, among others.
Briefly, a BSE includes evaluation of reproductive behavior, anatomical status, and evaluation of semen quality. Behavioral observations include libido, recognition of receptive females, and appropriate mounting behavior. Anatomic evaluations include body condition, with particular attention to the eyes, feet, and legs. Physical examinations are generally performed externally and rectally. The testes, scrotum, and epididymis are palpated, and scrotal circumference measured. The penis and prepuce are examined for appropriate anatomic development (e.g., penile deviations) as well as inflammation, abscesses, or adhesions. The prostate and seminal vesicles are evaluated by rectal palpation. Semen quality is evaluated by looking at volume, color, motility, and morphology. Evaluations are made in the context of age, breed, and species-specifics. Once breeding has occurred, measures of fertility generally are recorded.
Evaluations of female reproductive function have not been formalized in the same manner as those for males, largely due to the role of the stud in modern agricultural practice. Nonetheless, there are standard reproductive function examinations that carry the same importance in female animals as do the male examinations. The female-specific examinations include behavioral and anatomic components. Evaluation of germ cell production is generally not measured except by fertility and fecundity. Behavioral observations include age at onset of estrous behavior (puberty), behavior at parturition, offspring acceptance, and mothering behavior. Anatomical evaluations include body condition, examination of external genitalia, and evaluation of the internal reproductive tract by rectal palpation, vaginal speculum, and ultrasound (if clinically indicated). Fertility is monitored by recording the number of coital or insemination attempts needed for conception, (although, in the event of conception failure, the male contribution is also considered). The producer often keeps records of abortion incidence, birthing interval, retained placenta (especially for cows), mastitis (inflamed mammary gland or udder), and metritis (infected uterus). The colostrum management program is often monitored and evaluated using a colostrometer for colostrum quality and blood levels of IgG in the calf for transfer of passive immunity.
D. Interpreting the Comprehensive Veterinary Examination for Animal Clones
The CVE was devised for sick animals, and works well when the patient has a chief complaint requiring diagnosis and therapy. Laboratory work is designed to gather evidence to support the clinical diagnosis. For animal clones, however, the CVE is attempting to prove the negative (i.e., this animal is not materially different from a sexually reproduced animal), and therefore attempting to “prove” that the animal clone is healthy. Examination and diagnostic testing (such as blood work) as a screen for healthy animals (or animal clones) to determine if the animals have a general, non-specific occult abnormality is not straightforward. In the absence of the “complaint, diagnosis, and treatment” paradigm, if one value is out of range in an otherwise apparently healthy animal with an otherwise “normal” clinical chemistry screen, it is difficult to determine what level of concern to place on the anomalous value.
Reference ranges are based on a population of “normal” animals for a particular laboratory and species. In general, the reference ranges result from the collection of all of the measurements that have been taken by that laboratory, and calculation of the mean. The reference range is then set at the mean plus or minus two standard deviations, or a p<0.05 or 95 percent confidence interval. In other words, of any 20 test runs, one will have a value that is out of the range based on the statistical cut-offs as previously defined.
There may also be biological explanations for “out of range” values. For example, alkaline phosphatase is an enzyme found in every tissue, and is released when the cells of that particular organ or tissue are damaged. Elevated levels can be associated with diseases of the bones such as rickets, osteomalacia, hyperparathyroidism, and bone tumors, or as part of such normal processes as healing fractures, pregnancy, or growth.
To place this discussion in the context of the whole animal, we refer to the adage that “one treats the patient, not the blood work.” CVM’s determination that there is a biologically relevant difference between an animal clone and a sexually reproduced animal was based on a combination of statistical validity, weight of evidence, biological plausibility, and clinical impression; that is, a reliance on the body of evidence and expert veterinary judgment.
E. Parameters Evaluated in the Comprehensive Veterinary Exam for a Risk Assessment
The following series of tables presents the parameters used in evaluating the health status of animal clones when incorporated into a CVE.
Table H-1: Clinical Chemistry Parameters Associated with Organs and Organ Systems
(adapted from Hayes Principles and Methods of Toxicology 1994)
Table H-2: Animal Health Measures for Evaluating Livestock, Including Animal Clones - General Health Status
Condition at Birth and Perinatal (+48 hours) Period
|Caesarian/Vaginal Delivery||Birthing ease|
|Examination of Placenta||Cotyledon numbers|
|Immediate Post-parturition assistance||Fetal-neonatal transition|
Comprehensive Neonatal Examination
Take notice if LOS is present, especially in cattle and sheep.
|IgG||at 24-48 hours after birth|
Table H-3: Animal Health Measures for Evaluating Livestock, Including Animal Clones - Condition During Juvenile Post-Weaning Period (All Species)
Comprehensive Juvenile Animal Examination
Normal growth rate
Health/therapeutic records, with special attention to
|Diabetes||previously noted in animal clones|
|Nervousness||previously noted in animal clones|
Table H-4: Animal Health Measures for Evaluating Livestock, Including Animal Clones - Reproductive
(for males and non-dairy females, during first breeding cycle; early in lactation for dairy animals)
Comprehensive Breeding Soundness Examination (Males)
per established guidance on a species-specific basis
For seasonal breeders, exam should be performed during breeding season.
|Concomitant IgG measure in calf for measure of colostrum quality in beef calves, kids, and lambs. First parity dairy animals may not produce adequate quality colostrum. Comparisons should thus be made for appropriate parity level.|
Table H-5: Animal Health Measures for Evaluating Livestock, Including Animal Clones - Maturity, Aging, Lifespan
(immediately before animal use (e.g., slaughter))
Comprehensive Mature Animal Examination
- Respiratory rate
- Appetite/Feed consumption
- Body condition
- Body conformation
- Special Senses (ear, eyes, nose, throat)
- Peripheral lymph nodes
Health records kept on all breeding animals, and on all primary animal clones. They include all veterinary diagnoses, therapies, and vital statistics such as birth weight, weaning weight, physical exam findings, etc.
|Growth Performance/Weight gain|
Signs and Symptoms Observed in Animal Clones
-Other unspecified signs of early aging
Table H-6: Animal Health Measures for Evaluating Livestock, Including Animal Clones - Clinical Measurements
|CIAP (calf intestinal alkaline phosphatase)||for bovine species|
|Gamma glutamyl transferase|
|Hemo/Leukograms ( CBC)|
|Red Blood Cell count|
|WBC count including Differential|
|Blood (including leukocytes)|
The following table describes the nature of the laboratory tests that have been performed during a CVE, and what they measure. Some common abbreviations, expanded explanations of the functional descriptions, and how the tests are used in differential diagnosis were added during the review of the submitted data as part of the risk assessment.
|Table H-7: Standard Large Animal Panel (Blood Biochemistry) Often Performed During a CVE|
|Sodium (Na +)||Diet||Principle cation of extracellular fluid (ECF or plasma). Maintains osmotic pressure of ECF. Cannot evaluate the electrolytes (Na +, K +, Cl -, HCO 3) by themselves. They are interdependent. Their regulation depends on hydration status, disease, aldosterone, renin-angiotensin, acid/base status, etc. Low Na + may indicate - diarrhea, vomiting, congestive heart failure, renal disease, ruptured bladder. Elevations may indicate - dehydration, vomiting and diarrhea, inadequate intake, renal failure, increased salt intake, artifact from improper sample handling.|
|Potassium (K +)||Diet||Principle cation of intracellular fluid (ICF). Maintains osmotic pressure within the cell (osmotic balance). Elevations effect cardiac function. Plasma levels may be altered by diarrhea, renal failure, metabolic or respiratory acidosis (causes elevated K +, a.k.a. hyperkalemia), anorexia, hypoadrenocorticism (Addison’s disease), ruptured bladder, artifact from hemolysis of sample.|
|Chloride (Cl -)||Diet||Major plasma (ECF) anion. Used to calculate the anion gap. Also affected by acid/base status. Reductions seen with chronic vomiting.|
(HCO 3 -)
|Metabolism||Indicative of the CO 2 concentration in blood, buffers blood from radical pH changes. Used to diagnose metabolic or respiratory acidosis or alkalosis.|
|Anion Gap||Calculated||Calculated value to represent the unmeasured anions in the blood. High anion gap may indicate ketoacidosis, lactic acidosis, renal failure (uremic acidosis) and ethylene glycol toxicosis (organic acidosis). Low anion gap is RARE. It may indicate low plasma albumin, or high calcium|
|Blood Urea Nitrogen (BUN)||Liver||Urea is produced by liver and excreted by kidneys. High values may be pre-renal (dehydration), renal (disease of kidney), or post renal (disease of ureter, bladder or urethra). Low values may indicate chronic liver failure (lack of production) or dietary protein deficiency.|
|Creatinine||Muscle||Product of creatine metabolism by muscle tissue and excreted by kidneys. Used as an important measurement of kidney function. Resting level directly related to muscle mass. Higher in non-castrated males than females.|
|Calcium (Ca ++)||Diet, bone||Regulated by parathyroid hormone and calcitonin (from the thyroid). Vitamin D synthesized in liver important in dietary absorption. Acid base status and albumin level can affect blood levels. Co-factor for many enzymes. Key role in bone development, blood coagulation, cell growth, neuro-muscular transmission. Intestinal absorption may be affected by diarrhea or vitamin D deficiency.|
|Phosphorus (P)||Diet, bone||Similar to Ca ++ Indicative of parathyroid and thyroid gland function, renal function. Important as a buffer for the blood. Blood level primarily regulated by the kidneys. Abnormalities related to dietary deficiency, renal excretion and hormonal imbalances that would also affect Ca ++.|
|Magnesium (Mg ++)||Diet||Required for normal muscle and nervous tissue function. Co-factor for many enzymes, especially kinases and phosphatases. Influences the regulation of serum calcium. Mostly clinical relevance in a deficiency known as “Grass Tetany” usually from acutely feeding the cattle lush rye pasture which is notorious for Mg ++ deficiency.|
|Total Protein (TP)||Liver, Immune System||Consists mostly of proteins produced by liver (albumin, carrier proteins) and immunoglobulins. Used as indicator of total plasma volume.|
|Albumin (alb)||Liver||Regulates plasma osmolarity. Binds certain molecules (some drugs, Ca ++). Deficiency can be increased loss or decreased production. Loss may come from malfunctioning kidneys, intestine, or leakage into a body cavity. Decreased production may come from chronic liver failure.|
|Globulin (glob)||alpha-, beta-liver; gamma-B lymphocytes||Sum of globulins produced by the liver (transport proteins, like haptoglobin) and immunoglobulins (passive acquired from colostrum or endogenous production from B lymphocytes that have matured into plasma cells).|
|Albumin/Globulin Ratio (A/G)||Calculated||Used to determine if there is an overproduction of gamma globulin which may occur in autoimmune disease. Low values may be due to insufficient albumin (see albumin for discussion)|
|Glucose||Digestion, liver glycogen, synthesis||Indicative of the energy state of the animal. Can be reduced (hypoglycemia) in anorexia or due to artifact (sample handling), increased in diabetes mellitus (rare in cattle) or stress (common in cattle)|
|Alanine Aminotransferase (AST)||Liver, muscle||Present in liver and released if liver is damaged. May also indicate skeletal and cardiac muscle damage.|
|Sorbitol Dehydrogenase (SDH)||Liver||Present in cytosol of liver cells. High serum levels may indicate liver damage.|
|Alkaline Phosphatase (Alk Phos)||Organ Membranes||Present in hepatocytes, biliary epithelium, osteoblasts, placenta, intestine, and kidney. May be high in young animals due to bone growth. Also an indicator of cholestasis (impaired bile flow).|
|Gamma glutamyltransferase (GGT)||Organ Membranes||Present in hepatocytes, biliary epithelium, and kidney. Used to detect cholestasis. Has no involvement with the skeletal system to differentiate it from alkaline phosphatase. It is a better indicator of biliary stasis in large animals.|
|Total Bilirubin (T bili)||Hemoglobin Degradation||Increase in bilirubin can result in icterus (jaundice). Used as a measure of liver maturity and function.|
|Indirect Bilirubin||Hemoglobin Degradation (Non-Conjugated)||Bilirubin not conjugated to various carbohydrates for transport into bile in to the liver (elevations are from pre-hepatic sources). Value may be elevated by hemolysis or internal hemorrhage. Used to assess hepatobiliary function.|
|Direct Bilirubin||Hemoglobin Degradation (Conjugated)||Bilirubin conjugated to various carbohydrates for transport to allow for inclusion into micelles in bile for transport from the liver (elevated in post-hepatic obstruction). Elevated with biliary outflow obstruction. Used to assess hepatobiliary function.|
|Pancreas||Used by GI system to aid in digestion of starch and sugars. Elevations indicate pancreatic inflammation. Not important in ruminant species.|
|Cholesterol||Liver Synthesis, diet||Precursor for synthesis of steroid hormones, bile acids, and vitamin D. Constituent of cell membranes and bile micelles. Variations may be secondary to endocrine, hepatic, or renal disease.|
(CK or CPK)
|Muscle (skeletal and cardiac), Brain||Intracellular enzyme in skeletal and cardiac muscle. Used to detect damage to muscle.|
|Iron (Fe ++)||Diet||Ferric Iron associated with transferrin. Iron deficiency is often suspected as the cause of anemia.|
|TIBC (Total Iron Binding Capacity)||Transferrin production by Liver||Used as measurement of the total amount of transferrin.|
|Random Bile Acids (hBA)||Liver||Produced by liver and secreted into bile. Elevations indicate reduced liver function and not necessarily inflammation or biliary stasis.|
|Lipemia - Index||Lipids in plasma||Measure of the level of lipids in the circulation. Can be caused by diets high in fats and influenced by postprandial (after eating) sampling.|
|Hemolysis - Index||Lysis of red blood cells||Caused by lysis of red blood cells which results in release of hemoglobin into the plasma. Also used as an indicator of sample quality.|
|Icterus - Index||Bilirubin in plasma||Index measured by the color of plasma to indicate the amount of bilirubin. It is qualitatively measured by comparing to standard colors. It varies with labs, species, liver disease, dietary intake of carotene in cattle, among other things.|
|Insulin Like Growth Factor I (IGF-I)||Liver||Synthesized by the liver in response to growth hormone. Used as an indicator of the amount of growth hormone being produced. Elevations can be related to increased nutritional status, low values to negative energy balance. Higher in growing animals.|
|Estradiol (E 2)||Ovary||Synthesis is controlled by gonadotropins. Synthesis rates related to ovarian function in females. Used to monitor follicular and luteal activity.|
|Cortisol||Adrenal Cortex||Synthesis is regulated by the hypothalamus and pituitary. Involved in normal metabolism. Elevated levels are associated with stress.|
|Triiodothyronine (T3)||Thyroid Gland||Synthesis is regulated by the hypothalamus and pituitary. Involved in normal metabolism.|
Complete Blood Count
|Hematocrit (Hct)||Refers to the percent of blood that is occupied by red blood cells. Low values are good indicators of anemia.|
|Hemoglobin (Hb)||Protein used by red blood cells to distribute oxygen to other tissues and cells in the body. Low values are good indicators of anemia.|
|Red Blood Cells ( RBC)||The absolute concentration of red blood cells in the blood. A low red blood cell count is defined as anemia. High count is polycythemia.|
|Mean Corpuscular Volume (MCV)||The actual volume of the red blood cells. Larger red blood cells may indicate anemia due to B 12 or folic acid deficiency, also may caused by increase in reticulocytes; smaller red blood cells may indicate anemia due to iron deficiency.|
|Mean Corpuscular Hemoglobin ( MCH)||This test measures the amount of hemoglobin in red blood cells. Both hemoglobin and hematocrit are used to calculate this number. Low levels indicate anemia. Of limited diagnostic value.|
Hemoglobin Concentration (MCHC)
|This test measures the amount of hemoglobin in red blood cells. Both hemoglobin and hematocrit are used to calculate this number. Low levels indicate anemia.|
|RDW evaluates the range of sizes of RBCs in a blood sample. If anemia is suspected, based on other blood counts, RDW test results are often used together with MCV results to determine the cause of anemia.|
|White Blood Cells (WBC)||Leukocytes (WBCs) are produced by the immune system (in bone marrow) to help defend against infection. A high WBC count likely indicates an infection, whereas a low number might be an acute response where readily available cells are summoned to the site of infection or due to immunosuppression.|
|Segmented Neutrophils (segs)||Phagocytic cells present to guard against infection, particularly bacterial. Segmented neutrophils are mature neutrophils, and are the predominant white cell in non-ruminant mammals.|
|Banded Neutrophils (bands)||Immature neutrophils. Elevated levels occur in response to a recent infection.|
|Lymphocytes (lymphs)||T-cells, B-cells, and natural killer (NK) cells. Viral infections can either increase or decrease the total percentage of lymphocytes. It is the predominant white cell in ruminants.|
|Monocytes (monos)||Monocytes are a type of phagocyte that mature into macrophages. A low number can indicate a higher risk of bacterial infection.|
|Eosinophils (eos)||Active in killing parasites, can inhibit mast cells or release mediators of inflammation. A high number of eosinophils can indicate allergies or parasitic infections.|
|Basophils (basos)||Function unclear. A type of phagocyte that produces the anti-inflammatory protein histamine.|
|Platelets (Thrombocytes)||Tiny cells produced by the bone marrow to help blood clot formation. High number might indicate a blood disease. A decreased platelet count is called thrombocytopenia. Used to measure immune system function.|
|Measures the average volume of platelets. May be artifactually high due to clumping of platelets in blood sample.|
|Total Protein-refractometer (TP-ref)||The total amount of protein in the plasma measured by a refractometer.|
|RBC Morphology||General morphology (shape) of red blood cells. Poikilocytes - RBCs of irregular shape. Schizocytes - poikilocytes from fragmentation due to flowing through damaged small vessels.|
|Parasites||The blood sample is examined for the presence of parasites.|
Complete Blood Count
|WBC Exam||Morphological appearance of the white blood cells.|
|Plasma Appearance||General appearance of the plasma.|