- The test you may be most familiar with is looking at your horse’s hydration status. This is looking at the number of red blood cells circulating as a percentage of the total blood volume – this is referred to as the packed cell volume or PCV.
What do blood tests show in horses?
Blood tests can be used to look for antibodies to diseases such as equine infectious anaemia, equine viral arteritis, and piroplasmosis (a tick-borne disease). Negative test results will allow the horse to be bred or transported with no risk to other horses.
What is CA in horse blood test?
or prolonged time between blood collection and analysis. CA Calcium. Low levels may be associated with low protein levels. BUN Blood urea nitrogen.
What is neu in horse blood test?
Neutrophils – These are the most common white blood cells in the horse. They move rapidly to sites of infection or inflammation within the body. A low number of neutrophils (neutropaenia) is most often a result of an increase in demand for them.
What is the normal red blood cell count in horses?
The red blood cell count (RBC) is a measure of the number of circulating red blood cells in a given volume It is typically expressed as millions of cells per microliter. A normal RBC count in horses ranges between 6.5-11.9.
What does high white blood cell count mean in horses?
An elevated white blood cell count signals your horse is fighting an infection or inflammation. There are five types of white blood cells: basophils, eosinophils, lymphocytes, monocytes and neutrophils. Each type gives a vet clues as to the problem your horse has.
What does a low white blood count mean in horses?
A very low white blood cell count ( leucopenia ) can also be a sign of infection. This often occurs in response to a sudden severe infection and is seen before the horse has time to increase the production of white blood cells to respond to an infection or other inflammatory challenge.
What if neutrophils are high?
If your neutrophil counts are high, it can mean you have an infection or are under a lot of stress. It can also be a symptom of more serious conditions. Neutropenia, or a low neutrophil count, can last for a few weeks or it can be chronic.
What is an SAA test for horses?
The Clinical Pathology Laboratory in the AHDC is now offering Serum Amyloid A (SAA) testing. SAA is an acute phase reactant that is a sensitive and specific marker of inflammation in horses (a reported interval is <5 to 20 ug/ml). Values increase in response to inflammation and rapidly decline with resolution.
What causes high AST in horses?
Aspartate aminotransferase (AST) – Elevated AST levels are seen in cases of acute liver or muscle damage. Levels peak 24 – 48 hours following injury and will return to normal 10 – 21 days following resolution. Combined with CK measurements, AST provides a useful measurement of muscle damage in cases of ‘tying up’.
What causes high liver enzymes in horses?
Increased hepatic enzyme activity often is a result of secondary liver disease from toxemia, hypoxia, and so forth, and hepatic function remains normal in most horses with these disorders.
What does high fibrinogen mean in horses?
Fibrinogen is an acute phase reactant protein and the liver increases production of this protein in response to inflammatory cytokines. It is considered a moderate, but delayed, marker of inflammation in horses. Concentrations increase within 24-48 hours of an inflammatory stimulus and moderate increases are seen.
What are the symptoms of equine infectious anemia?
What are the clinical signs? The disease is characterized by recurrent febrile episodes, anemia (low red blood cell count), thrombocytopenia (low blood platelet count), inappetance, depression, rapid loss of weight and edema (fluid swelling) of the lower parts of the body, and sometimes incoordination.
Why would a horse be anemic?
The main causes of anemia in horses are blood loss (usually from injury, but also from conditions like cancer or gastric ulcers), blood-cell destruction and reduced red blood cell production. Some infections, including equine infectious anemia, babesiosis and trypanosomiasis, lead to the destruction of red blood cells.
Is Red Cell good for horses?
Supports healthy blood cell production Red Cell is a palatable yucca-flavored vitamin-iron-mineral supplement for horses. Red Cell is formulated to provide supplemental vitamins and minerals that may be lacking or are in insufficient quantities in a horse’s regular feed.
Blood Tests Explained
Obtaining a blood sample from your horse can be done for a variety of reasons, including sickness, tracking response to therapy, and basic health and fitness assessments. Many different chemicals can be detected in the bloodstream. The purpose of this guide is to explain what is being measured and what anomalous findings may indicate. It is common practice to provide reference ranges, which indicate the usual values of measurement for a horse. These figures are frequently for the typical horse, and as a result, some horses will naturally fall outside of these ranges without affecting the results.
Red Blood Cells are a kind of blood cell.
This percentage might range from as low as 24 percent to as high as 48 percent.
Anemia is often indicated by a low platelet count and red blood cell count.
- Strength, dullness, decreased appetite, and decreased exercise tolerance are all indicators that your horse may be suffering from anaemia.
- Most of the time, it indicates that the horse is dehydrated or that the animal has been “wound up” previous to the blood sample being taken.
- Other disorders, such as anemia, might induce a rise in the PCV and RBC count in rare cases.
- The reason why the PCV and RBC count do not always correspond is due to variations in the typical red blood cell volume.
- A measure of the average quantity of haemoglobin found in each red blood cell, known as Mean Corpuscular Haemoglobin (MCH).
- The protein found in red blood cells that permits them to transport oxygen throughout the body is known as hemoglobin.
- Blood Cells of the White Blood Cell Type It is estimated that the horse has five different kinds of white blood cells (leukocytes).
White Blood Cell Count (WCC) – The total number of white blood cells in the blood is represented by this value.
It is possible that an excessive amount of bacterial or viral infection, bone marrow illness, or endotoxaemia will cause a reduction in the total number of white blood cells (leukopaenia).
In the body, they are able to migrate quickly to areas of infection or inflammation due to their speed.
When there has been a quick outbreak of an infectious or inflammatory process, it is possible that the neutrophils in the blood have been depleted as a result of the response.
Neutropaenia can be caused by a decrease in neutrophil production as well as by endotoxaemia.
This is most commonly caused by a bacterial or viral infection, an accident, stress, or the use of medication.
Cells called monocytes are critical in the breakdown of damaged tissues as well as the eradication of microorganisms.
Additionally, monocytosis may be observed during the healing period following a viral infection.
Eosinophils — These cells are most typically connected with parasite illness as well as with allergy diseases, according to the National Institutes of Health.
Like monocytes, eosinophils can be absent in a blood sample from clinically normal horses, and so eosinopaenia is not a clinically important finding in these animals.
Basophilia is a condition in which they are detected in large quantities, and it may signify a long-standing allergic illness or the continued recovery from colic.
Excitation and exercise, as well as some malignancies, can result in lymphocytosis (an increase in the number of lymphocytes).
Endotoxaemia, which is characterized by decreased lymphocyte counts, can occur as a result of stress, viral infection, or a severe and overpowering bacterial infection.
Thrombocytopenia is defined as a decline in the number of circulating platelets, which is frequently caused by an immune-mediated illness that causes platelet destruction.
It is only in rare cases when an increase in the number of circulating platelets is seen.
Biochemical Examinations The presence of certain substances in a sample of your horse’s blood can provide information on the function of certain organs or metabolic pathways.
Adrenocorticotropic hormone (ACTH) is a hormone that is measured in the diagnosis and therapy of Cushing’s illness, among other things.
Alkaline Phosphatase (ALP) is a digestive enzyme that breaks down alkaline phosphate.
The age-related reference ranges are quite diverse.
Levels will reach their maximum 24 – 48 hours after the injury and will return to normal 10 – 21 days after the damage has been resolved.
Bile acids – These are expelled in the bile as bile salts, which are salts of bile acids.
Blood cortisol levels may be elevated in horses suffering from Cushing’s disease or in horses that are under stressful conditions.
Increased levels in the horse nearly invariably indicate acute muscular injury, as previously stated.
When measuring muscle injury, CK is frequently measured in conjunction with AST.
Horses with primary kidney disease or other disorders affecting the kidneys, such as dehydration, shock, and post renal obstructions, may have elevated amounts of creatinine in their urine.
Increased levels of bilirubin in the blood suggest liver illness.
It is also possible to detect an increase in the presence of overtraining.
In suspected cases of horse metabolic syndrome, as well as in some cases of equine Cushing’s illness, this parameter is determined.
Elevated glutamate dehydrogenase (GLDH) levels are specifically associated with acute liver disease (ALD).
During the course of an examination into horse metabolic syndrome, it may be determined whether or not insulin levels are increased in the animals.
Body produces and breaks down lactate on a continual basis, which is called lactate production.
It is necessary to divide LDH into its distinct isoenzymes since they are associated with different organs.
Increased LDH may suggest liver, muscular, or intestinal illness, depending on the exact isoenzyme that has been elevated.
Variations in the total protein value may be due to changes in the values of one or more of the proteins found in the blood, such as the following: Albumin – Increased levels of albumin are nearly invariably caused by dehydration, as previously stated.
Protein can be excreted from the body through the colon, which is the most frequent route, or it can be excreted through the kidney.
The total globulin protein is composed of three fractions: alpha, beta, and gamma globulins, respectively.
When a horse is fighting an illness, increased globulin levels may be seen in the blood.
When these levels are low, it suggests that the mare’s colostrum did not adequately transmit immunity to the foal, and the foal may require transfusion of plasma containing higher gamma globulin levels to recover.
Serum amyloid A (SAA) and fibrinogen are two examples of such substances.
In reaction to tissue injury, fibrinogen levels will rise.
Fat Transport by Triglycerides – Triglycerides are responsible for the transportation of fat throughout the body.
Urea – Urea is a waste product generated by the liver and eliminated by the kidneys.
ElectrolytesCalcium – Because the bulk of this electrolyte in the blood is tied to albumin, the levels of this electrolyte should be evaluated in relation to albumin levels.
Insufficient amounts may be caused by liver illness, insufficient nutrition, or late pregnancy or breastfeeding.
Horses with low chloride levels are frequently observed after they have sweated excessively.
The presence of low phosphate in horses whose blood samples were collected shortly after exercise is not uncommon.
Potassium loss is the cause of the low levels.
High levels may be an accidential finding when red blood cells have broken down (haemolysed) in the sample prior to testing, or they may be the result of muscle damage during the testing procedure itself.
Low amounts of the hormone can also be detected in young foals who have suffered bladder injury. In most cases, elevated sodium levels indicate that the person is dehydrated.
Top 10 Blood Tests
Your horse is feeling under the weather, and your veterinarian is stumped as to what’s wrong. “I think we should probably do some basic laboratory work,” he says. “Perhaps that will assist us in determining what to do.” Every horse owner has given the go-ahead for “basic lab work,” which includes a complete blood count and chemistry panel, as well as other tests. I’ll try to clear up some of the ambiguities surrounding basic blood work. Starting with the most common reasons I recommend blood work and the factors I take into consideration when interpreting the results, I’ll move on to the next section.
The importance of blood work in the toolbox of your veterinarian, as well as how to make the most of the results, will be discussed.
BLOOD-TEST BASICS
The blood in your horse’s body serves as his primary internal transport system. His blood transports oxygen from his lungs to his other organs, distributes nutrients from his intestines, transports proteins or other specialized cells to the locations where they are needed, and removes waste items from his body for removal. When your horse is in good health, the components in his blood tend to stay within a specific range of values. When anything is wrong, it is possible for one type of cell or chemical to go out of balance.
- A sample of blood can be subjected to hundreds of different tests, ranging from a basic count of red blood cells to a test for hormone levels that could suggest the presence of a specific illness.
- This test offers information on the amount and characteristics of red and white blood cells that are circulating in your horse’s system, as well as a breakdown of the different types of white blood cells in your horse’s system.
- These tests also include the evaluation of proteins that are implicated in inflammation.
- Your horse is losing weight at an alarming rate.
If your veterinarian judges that these fundamental concerns aren’t the source of your horse’s weight loss and he discovers nothing odd during a physical examination, he may recommend blood tests to rule out more serious reasons of your horse’s weight loss, such as liver or kidney disease, in your horse.
- There are three main causes of fever: inflammatory problems, viral infections (such as the flu), and bacterial infections (such as the flu).
- It can also assist your veterinarian in determining the severity of your horse’s condition.
- A blood test may be necessary if your horse stops eating but is otherwise healthy and your veterinarian is unable to detect anything abnormal during a physical exam.
- It just doesn’t seem like your horse is right.
- Screening on a regular basis.
- This is especially beneficial for older horses that are prone to chronic illnesses that develop gradually with age.
- Although routine blood testing can provide you and your veterinarian with a great deal of information about your horse’s health, a single lab value or combination of tests does not necessarily convey the complete story about your horse’s condition.
To get the most out of your horse’s blood results, be sure your veterinarian has a complete history of your horse’s health and is capable of doing a comprehensive physical examination.
TOP TEN TESTS
It is possible that you may be overwhelmed by a list of as many as 40 or 50 tests on your CBC and chemistry panel report, each with findings, a normal range, an indicator of whether the test is normal or abnormal, and comments from the laboratory. Even your veterinarian may find it difficult to understand! The significance of each and every statistic on the report depends on the circumstances of your horse. If you are treating a post-operative colic patient in critical care, the tests that we pay the greatest attention to will be different from the tests that an internal medicine expert will pay close attention to in a general practice environment.
Every single aberrant figure does not always indicate that your horse is suffering from a condition.
A high figure, on the other hand, may suggest a problem, but a result that is below the usual range has little significance.
Test1: Red Blood-Cell Count (RBC)
What it is is as follows: When you check your horse’s RBC, you can see how many red blood cells are circulating in the horse’s circulation. What it informs you is as follows: A low RBC count might suggest anemia, whereas a high RBC count is most often associated with dehydration. Anemia in horses is most usually caused by another chronic condition in the horse’s body. If your veterinarian observes that your pet’s RBC count is extremely high, he or she may recommend fluid treatment. Tests that are related: It is always necessary to perform a few additional tests in addition to the RBC, including the hematocrit (also known as “packed-cell volume” or PCV), which measures the proportion of red blood cells in relation to the total volume of blood, and the hemoglobin, which measures how much of the protein hemoglobin is present in the blood.
Test2: White Blood-Cell Count (WBC) and Differential
The nature of the phenomenon is as follows: When you check your horse’s RBC, you can see how many red blood cells are currently circulating in his or her circulation. What it informs you of is the following. A low red blood cell count may suggest anemia, whereas a high red blood cell count is more often associated with dehydration. A horse’s anemia is most likely caused by another chronic condition in the horse’s body. Veterinary fluid treatment may be recommended if your pet’s red blood cell count (RBC) is very high.
Test3: Fibrinogen
In short, fibrinogen is a protein that is created in the liver and released early in the course of an infection or an inflammation. What it informs you is as follows: A fibrinogen level that is substantially increased implies chronic inflammation. If it is significantly raised, it may suggest an infection somewhere in the body, which can aid your veterinarian in determining whether or not to provide medicines. The presence of an abnormally high fibrinogen level is associated with numerous abscess-producing illnesses.
A test for Serum Amyloid A, another acute-phase inflammatory protein, offers information that is comparable to the one described above. This test may be performed “stall-side” in order to obtain quick findings, and it can be important in determining whether or not to treat with antibiotics.
Test4: Creatinine
What it is:Creatinine is a waste product of muscle metabolism that is excreted through the kidneys.What it tells you:A high creatinine level indicates that your horse’s kidneys are not functioning properly.Related tests:If your horse’s kidneys are failing, the blood urea nitrogen level (see below) is likely to be elevated as well.What it tells you:A high creatinine level indicates that your horse’s kidneys are failing.
Additionally, electrolyte abnormalities such as high calcium and reduced phosphorus are associated with renal failure, as is decreased red blood cell count (RBC).
Test5: Blood Urea Nitrogen (BUN)
What it is:Urea is a waste product of protein breakdown in the liver, and it is excreted by the kidneys in the same way as creatinine is eliminated. What it informs you is as follows: Elevated BUN levels are most typically associated with renal failure, while this test can also indicate other conditions such as dehydration in some cases. Anemia caused by liver illness or a low-protein diet may result in decreased BUN levels. Tests that are related: When examining renal disease, creatinine and BUN are frequently examined simultaneously, as are calcium, phosphorus, and red blood cells (RBC).
Test6: Gamma Glutamyl Transferase Enzyme (GGT)
This enzyme assists in the metabolism of nutrients as well as the management of inflammation in the body, according to its definition. It has a particularly vital role in the liver, where it aids in the breakdown of medicines and poisons. What it informs you is as follows: A high level of GGT is most frequently linked with liver or bile duct disorders. bile (a chemical generated by the liver) is sent to the gut, where it assists in the absorption and digestion of fats, among other things, through a tube called the bile duct.
GGT levels can also rise in the presence of acute (rapid) liver damage.
Tests that are related: With chronic liver injury, a low RBC count and a reduced albumin level (see Test10) may be seen.
Other diagnostic procedures, such as liver function tests, ultrasonography, or biopsy, are used to make a more specific diagnosis in some cases.
Test7: Bilirubin
What it is is as follows: A substance called bilirubin is expelled in bile after being liberated from hemoglobin (the oxygen-carrying component of red blood cells). It is unconjugated bilirubin that is the first breakdown product that is transported to the liver for processing. As soon as bilirubin enters the liver, it is conjugated with another material, which makes it dissolvable in water and so expelled. Total bilirubin, conjugated bilirubin, and unconjugated bilirubin are all measured by the lab.
Unconjugated bilirubin levels rise in the presence of liver disease or when your horse is just not eating, so this reading should be viewed with caution.
Tests that are related: BILirubin elevations are frequently examined in conjunction with other liver tests such as GGT, liver function tests, ultrasounds, and biopsies, among other things.
Test8: Creatine Kinase Enzyme (CK)
This enzyme breaks down molecules that are associated with energy storage in order to release energy for muscular contraction. What it does: What it informs you is as follows: Elevated creatine kinase (CK) readings indicate muscular breakdown, and they are most frequently observed following a tie-up (severe muscle cramping) event. Within a few hours of a severe incident, the concentration of creatinine might rise to dangerously high levels. After anything as simple as an intramuscular injection or a particularly challenging training session, levels that are somewhat raised or “slightly over normal” might be seen.
This enzyme takes a bit longer to reach its peak concentration in your horse’s bloodstream and remains in the bloodstream for a little longer than CK.
The discharge of myoglobin into your horse’s circulation as a result of severe bouts of muscle breakdown can be harmful to your horse’s kidneys.
Test9: Glucose
Sugar is running in your horse’s system, and it is what it is. What it informs you is as follows: In a variety of disorders, such as Cushing’s disease and insulin resistance, elevated blood sugar levels might be observed. If your horse is really ill, his glucose levels may be raised as a result of shock or a severe systemic illness. It is very rarely raised shortly after a meal or in reaction to a “fight-or-flight” response. Tests that are related: If your horse’s blood glucose level is elevated, it may be recommended that you get him tested for Cushing’s illness or insulin resistance.
Test10: Protein
What it is: Total protein is a term that refers to the measurement of albumin and globulin together. When the liver produces albumin, it performs a variety of critical tasks. These include aiding in the maintenance of fluid balance in the bloodstream and the transportation of vital molecules throughout the body. Globulins are proteins that are generated by the liver and by the immune system in response to infection. They also serve a variety of roles and include antibodies that aid in the fight against infection.
Severe diarrhea or other gastrointestinal illnesses can also cause protein levels to decline significantly.
Tests that are related: Protein levels can be affected by a wide range of diseases and factors. If protein levels are abnormal, the results of tests for renal disease and liver disease, as well as the results of the complete blood count (CBC), will all be carefully evaluated.
McKee-Pownall Equine Services
| Term | Definition |
|---|---|
| CBC | Complete blood count, includes RBC, HGB, HCT, WBC, differential, MCV, MCH, MCHCplatelet values |
| RBC | Total red blood cell count, if low = anemia, if high = erythrocytosis |
| HGB | Hemoglobin –measures the oxygen carrying ability of the RBC |
| HCT | Hematocrit –measures % of red blood cells in whole blood, also called “packed cell volume” (PCV) |
| MCV, MCHMCHC | Calculated values that correlate the amount of hemoglobin and the size of the red blood cells |
| Platelets | A component of the blood clotting system |
| WBC | Total white blood cell count, which provides an overall number of all types of WBC’s – neutrophils, lymphocytes, monocytes, eosinophilsbasophils. They play a role in inflammation and fighting infection |
| Differential | Quantifies the amount and relative percentage of neutrophils, lymphocytes, monocytes, eosinophilsbasophils |
| Neutrophil | These cells typically make up about 2/3 of the total WBC count. |
| Lymphocyte | Usually make up about 1/3 of the total WBC count. If your horse was stressed at the time of collection (recent excitement of exercise) this may elevate the count. |
| Monocytes,Eosinophils,Basophils | Typically very low percentage on the differential, elevations can indicate certain inflammatory conditions such as allergies or parasitism. |
| Term | Definition |
| Chemistry Profile | panel of tests that analyzes organ (kidney, liver etc.) functions |
| NA | Sodium. Plays a role in water regulation. Main source is from the diet, and level can indicate intake or possibly loss (diarrhea) |
| K | Potassium. Elevated levels can be deadly! Increases can be due to renal disease, Addisons, HYPP in Quarter Horses. Low levels can be due to decreased intake or loss (diarrhea), excessive sweating. |
| tC02 | Total bicarbonate level. Increased levels indicate metabolic alkalosis. Decreased levels indicate metabolic acidosis. Important in racing industry as increased levels = positive test, fines, suspensions etc. |
| CK | Creatine kinase. Muscle enzyme, elevated with muscle damage. Peaks 4-6 hrs. after injury. Peaks before AST. |
| GLU | Glucose. Can be elevated with a recent meal, decreased with liver dysfunction, or prolonged time between blood collection and analysis. |
| CA | Calcium. Low levels may be associated with low protein levels. |
| BUN | Blood urea nitrogen. Increases with kidney disease. Decreases with liver failure, low protein dietanabolic steroid use. |
| CRE | Creatinine. Increases with kidney disease. |
| AST | Liver and muscle enzyme, will be elevated with liver or muscle damage. Peaks about 24 hours after injury has occurred |
| TBIL | Total bilirubin level.Measures liver function. May be elevated by liver diseaseanorexia (not eating). |
| GGT | Liver enzyme, elevated with bile stasis, large colon obstruction. |
| ALB | Albumin, a type of blood protein; can be decreased in chronic liver disease, inflammation, kidney disease, intestinal malabsorptionmalnutrition. Increased levels indicate severe dehydration. |
| GLOB | Globulins, a type of blood protein; often increased with inflammation, immune-mediated diseasesome neoplasms. Decreased levels occur with passive transfer failure in foals, severe protein loss. |
| A/G Ratio | Compares the ratio of the amount of albumin to globulins |
| TP | Total protein, measures protein in the blood; can indicate dehydration if elevated. Decreases with kidneyGI disease, liver failurestarvation |
Blood Tests for Performance Horses: How Helpful Are They?
The dates are January 17, 2020 through June 4, 2021. The condition, fitness, and overall health of the horses under their care is something that owners and trainers of performance horses are constantly seeking for new ways to assess them. Are managers providing the appropriate hay and grain in the appropriate amounts at the appropriate times? Is it possible that they are working the horses too much or not enough? If so, does the horse have some sort of concealed condition about which the owner is completely oblivious.
After all, the outcome will indicate virtually everything about this particular horse’s current condition, right?
A blood test can be useful in detecting the health of a horse, and a series of blood tests can be even more useful in determining the horse’s condition.
On the issue of blood analysis and its relevance to feeding performance horses, Per Spangfors, a veterinarian at Euro-Vets AB in Simlangsdalen, Sweden, presented a paper for a Kentucky Equine Research (KER) nutrition conference on the topic of feeding performance horses.
The author stated that the majority of people believe such statistics to be the ultimate truth and that this figure will remain static until the next blood sample is taken.” As long as the individual in question also compares that number with a reference value and determines that his horse’s value is within the anticipated boundaries for health, the clinical image is of little consequence to him, and regardless of how the horse seems, he believes that he is in good condition.
If the horse enters a competition and fails, the individual raises his or her eyebrows and asks why the blood test did not indicate that the horse was not in a fit state to compete in the event in question.
Furthermore, he should be aware that the clinical image of his horse is the truth, regardless of what the blood test and normal values show, and he should have sought the advice of an expert regarding the interpretation of the studies, but the absolute truth is never disclosed.” Depending on the time of day, exercise routine, food, feeding schedule, and other factors, the horse’s blood chemistry is continually changing.
The interpretation of blood tests is an art, according to Spangfors, even if the samples are obtained at the same time every day for a period of time.
You must be able to see patterns in the figures and comprehend the dynamics that exist between the various parameters.
First and foremost, when you discuss the real-world issue with the horse handler and compare the outcomes of the tests, you may improve your ability to interpret test findings.
It is feasible to make educated guesses about the nutritional status of specific nutrients if you have a reputable laboratory and know which parameters to check and when to collect the samples.” The author went on to say, “In general, it is far simpler to recognize when something is wrong than it is to recognize when the situation is ideal.
- Alternatively, it is simple to identify a copper shortage, but difficult to determine when copper is best for this horse.
- When training a horse, it is important to consider the findings of the tests in conjunction with what you see and feel about the horse.
- “However, because it is only a statistical value, there are numerous exceptions.
- Due to the fact that analysis processes, analytical temperatures, hardware, and sample handling varies from one laboratory to another, each laboratory must have its own set of normal values.
- The finest normal data are obtained directly from the horse.
For this reason, standardizing your sample processes and making notes on sampling circumstances for future reference are also recommended.” Spangfors went on to say, “The vast majority of the characteristics measured in blood provide an unspecific picture of the metabolic processes,” says the author.
- We may find patterns in the figures as a result of this, and we do not necessarily need numbers outside of the typical ranges to identify pathologic circumstances.
- A variety of dietary abnormalities have an impact on the hormonal system.
- This is why, if you examine a large number of characteristics, you can detect a pathogenic pattern.
- In order to accurately evaluate hormone levels, additional care must be taken, and the test is most often utilized to confirm a suspected abnormality identified by an ordinary blood test.
- Thus, glucose tolerance tests may be used to stimulate insulin, T4, T3, and cortisol production, whereas thyroid releasing hormone can be used to stimulate just T4 and T3 production (TRH).
According to Spangfors, “normal values should be utilized with extreme caution, and comparing a fresh sample to earlier samples from the same horse is the preferred way.”
What a blood test can tell you
Despite the fact that blood tests can give your veterinarian with a great deal of information about your horse’s health, the results of these tests can be difficult to interpret. Veterinarian Anna Hollis, from the American Humane Society, explains what these tests check for. There are a variety of reasons why your horse may need to have a blood sample drawn. Many veterinary facilities now promote a “well horse” program, which may involve yearly blood tests to check on the overall health of your horse.
Many illnesses and abnormalities with organ function can be effectively treated or managed to extend or improve the quality of your horse’s life if they are discovered and treated early enough.
Blood tests are commonly used to diagnose hormonal diseases such as PPID (Cushing’s disease) and to look for signs of possible tapeworm infection using the tapeworm ELISA test.
How is the blood collected?
Blood is normally drawn from the jugular vein in your horse’s neck, which can be drawn from either side of the horse’s neck. Normally, blood is collected in special containers, which are typically specifically constructed tubes known as Vacutainers. These containers can be basic or include different compounds that help to preserve the blood for a range of tests. Other blood veins, such as the cephalic vein on the inside of the front leg, can also be used to collect blood, but the jugular vein is the most commonly utilized since it is easily accessible and most horses don’t seem to mind being poked or prodded during the operation.
Different types of test
Many different components make up blood, and it can be examined as whole blood or after it has been separated into serum (the liquid element of the blood that contains no cells) and plasma (which includes cells) (which is serum plus proteins that are involved with clotting).
Whole blood testing
The total amount of red blood cells, white blood cells, and platelets in the blood is determined by testing the whole blood.
- Red blood cells are the cells that transport oxygen throughout the body. Horses often have a high packed cell volume (PCV) due to the fact that they are built to be athletes and, as a result, require a large number of oxygen-carrying cells to function well. Horses with a PCV of 35–45 percent are common among Thoroughbreds, with warmbloods and draft horses having a somewhat lower PCV of 30–40 percent. White blood cells are cells in the blood that fight illness. There are numerous distinct forms of white blood cells, including neutrophils, lymphocytes, monocytes, eosinophils, and basophils. Neutrophils are the most common type of white blood cell. The cells differ in terms of what they perform, where they are produced, and how long they remain in the circulation after being removed. A leucocytosis is an increase in the total white blood cell count that can occur at times of stress or excitement, during physical activity, and when infection or inflammation occurs. Increased white blood cell count is known as leucopaenia, and it is typically an indication of infection because the white blood cells are redirected out of the circulation and into an infection-infected region where they can fight the infection. In rare cases, leucopaenia can be caused by a decrease in the generation of white blood cells. The neutrophil is the most abundant white blood cell in the body of a healthy horse, accounting for around 50–70 percent of the total white blood cell count. The lymphocyte, which accounts for 30–45 percent of all white cells, is the second most frequent kind of white cell. In tiny quantities, eosinophils (white blood cells), monocytes (white blood cells), and basophils (red blood cells) are present
- Platelets (red blood cells) are involved in the blood clotting process. They will frequently clump together during routine blood analysis, resulting in an erroneous count when the study is performed by a machine. If your veterinarian suspects a problem with clotting, he or she may collect blood in a special tube intended to minimize platelet clumping. A blood smear will be examined under a microscope to validate the machine’s platelet count
- Clotting times may also need to be measured in some cases. Depending on whether your horse is suspected of having a blood clotting problem, this procedure may be conducted before to a liver biopsy (since the liver is critical for the production of proteins that regulate bleeding) or after a liver biopsy. This entails specialized tests being done on blood samples that have been collected in specific tubes.
Serum and plasma testing
The serum or plasma is analyzed in order to rule out any other potential abnormalities.
- Evaluating muscle enzymes (CK and AST) for evidence of muscle damage, and liver enzymes (often GGT and AST, but also other enzymes such as SDH) for indicators of liver damage is standard procedure. Because the bile acids are a good indicator of liver function, they are frequently tested in situations when there is an increase in GGT or AST levels. It is also possible to test for liver function using bilirubin, however this is less precise and alterations can be noticed in horses with a variety of different diseases, most notably when they are not eating as much as they should. Renal function is measured by urea and creatinine levels in the blood
- Protein levels in the blood are monitored both as a total protein level and as levels of albumin and globulin, which are the primary proteins that contribute to the total protein level. An rise in total protein may be due to an increase in albumin, globulin, or both
- Fibrinogen and SAA are examined to search for symptoms of infection or inflammation, as well as to monitor the response to therapy. A decrease in total protein may be due to a decrease in albumin, globulin, or both. It is important to note that the SAA increases extremely fast during an illness and decreases very quickly once the infection has begun to cure, thus this might be an useful sign that your horse is receiving the necessary medication. As a result, SAA may be monitored frequently – for example, every 48–72 hours – in severely ill horses, where it can be used as an early indicator of whether things are getting better or worse
- Electrolytes are frequently included as part of a routine blood profile, and increases or decreases in electrolyte concentration can be caused by a variety of conditions, so changes in electrolyte concentration should be interpreted with caution
Specialist blood tests
Along with determining the overall health of your horse’s body, blood tests may be used to detect indications of exposure to certain infections, infection with specific illnesses, and changes in hormone levels.
- When it comes to older horses, PPID is quite frequent and can cause a variety of clinical issues, including an increased risk of laminitis, infections, hoof abscesses, and dental difficulties. Fortunately, it is now relatively straightforward to diagnose and treat the disorder, since a simple blood test can be performed to check for the presence of a hormone known as ACTH. When the ACTH levels are extremely elevated, the diagnosis of PPID can be established with confidence. When there are borderline or unclear results, further tests may be performed to help explain the situation
- Nevertheless, in the vast majority of cases, the diagnosis is straightforward. In order to ensure that the horse’s ACTH levels remain within normal range after treatment, the test should be repeated periodically. Equine metabolic syndrome (EMS) is a disease in which the horse’s insulin and glucose levels are not properly controlled. This leads to fat deposition, a predisposition to gaining weight, and an increased risk of laminitis, among other symptoms. Blood glucose and insulin testing can aid in the diagnosis and management of EMS
- Tapeworm testing can also be beneficial. ELISA is used to monitor tapeworm burdens because, in contrast to other forms of worm, tapeworms are difficult to detect on the basis of a faecal worm egg count since they do not release eggs on a consistent basis. This blood test has been created to screen for antibodies to tapeworms in order to determine whether or not a horse has recently been exposed to a large number of tapeworms in order to assist diagnose the situation. The presence of a very high result would indicate the need to employ a particular wormer that targets tapeworms. Strangles, on the other hand, take a long time to reduce in antibody levels, even after effective treatment, therefore repeated positive findings should be read with care
- Testing for the presence of antibodies to the bacterium that causes strangles has been established to aid in the diagnosis of the disease. In particular, because some horses might have the bacterium without displaying any clinical indications, this is an extremely valuable test. Because antibody levels do not rise until two weeks after infection with the disease, the test cannot be used to rule out a horse who has only recently been exposed to the disease. However, a negative result in the majority of cases indicates that the horse does not pose a risk of spreading strangles to other animals. Because he is not a carrier and is not likely to be incubating the disease, if the antibody levels come back as very low – a negative result – the horse is generally considered to be safe to move to another yard. If the horse does not come from a yard suspected of having strangles, the horse is generally considered to be safe to move to a new yard. The blood test can also be utilized in the treatment of a strangles epidemic or for the detection of other infections. The majority of the time, horses are needed to have negative tests for a variety of illnesses before they may be used for breeding or moved overseas. Tests for antibodies to illnesses such as equine infectious anaemia, equine viral arteritis, and piroplasmosis can be performed on blood samples taken from the horse (a tick-borne disease). If the test findings are negative, the horse will be able to be bred or transferred without putting other horses at danger.
Cross matching
Horses, like people and dogs, have a variety of blood types to choose from. It is feasible to administer blood transfusions to horses; however, cross matching should be undertaken prior to administering a blood transfusion to a horse. Especially crucial when providing blood to a broodmare or a horse that has already received a blood transfusion since they are more prone to become sensitized and react negatively when given blood from a blood type that is different from their own. Fortunately, horses seldom require blood transfusions; nevertheless, this means that there are only a few laboratories that can provide a cross-matching service.
If your horse is unfortunate enough to require a transfusion, blood will most likely be drawn from a horse who is likely to be a universal donor (often a draft type gelding) rather than waiting for a cross matching result, which can take several hours.
Interpreting the results
Blood testing is quite difficult, and there are a variety of reasons why your veterinarian may decide to collect a sample of your horse’s blood. In addition, it’s important to keep in mind that there are several factors that might cause a blood test result to be abnormal; thus, if you have any questions about your horse’s test results, your veterinarian is the best person to guide you through them.
What can your horse’s blood tell you?
A lithium heparin tube, a serum tube, and an EDTA tube are three types of tubes that are often used for electrolytes, biochemistry, and CBC testing, among other things. When we work as veterinarians, it is something we do virtually every day: we take blood samples from our patients in an attempt to figure out what is wrong with them internally. What we’re looking at, though, is something you may not have thought about. This article is intended to provide you with a high-level overview of the types of tests that may be conducted on blood and, consequently, the advantages of doing blood tests when your horse is sick.
Complete Blood Count
A complete blood count (CBC) examines the number and composition of red blood cells, as well as the number and composition of white blood cells such as neutrophils, lymphocytes, monocytes, basophils, eosinophils, and platelets. When it comes to horse hydration testing, you may be most familiar with the results of this procedure. This is done by calculating the number of red blood cells in circulation as a proportion of the total blood volume – this is known as the packed cell volume, or PCV, for short.
- The haematology results of a mare suffering from a bacterial illness are shown here; notice the raised white blood cell count and granulocytes.
- White blood cells are responsible for combating these germs.
- An increase in the eosinophil count in your horse is usually connected with parasitism or allergies.
- Fibrinogen can be measured in the bloodstream.
Biochemistry
Biochemistry is the study of enzymes, proteins, and by-products created by the body, and it can assist us in determining the source of a health problem. However, several of these enzymes are not exclusive to a single organ and might be raised owing to a variety of factors. This is a concern because So the results must be interpreted in light of the clinical picture and other blood results, in addition to their own interpretation. In general, a basic biochemistry profile will allow us to look at enzymes that are associated with the health of the kidneys, liver, and muscle, to mention a few organs and tissues.
- Globulin levels can be raised in chronic inflammation, while albumin levels can be low if the protein is being wasted, as in diarrhoea, or if there is a problem with the creation of the protein, like in liver illness.
- The enzyme aspartate aminotransferase (AST) can be high in situations of muscle injury, such as when your horse ‘tied up,’ as well as elevated in cases of liver damage, according to the National Institutes of Health.
- Again, this must be considered in the context of the clinical picture, and it is possible that additional diagnostic modalities, such as ultrasonography, will be required to see the liver.
- Lactic acid is created when cells are forced to operate under anaerobic circumstances, i.e.
This is more likely to occur in horses who are dehydrated, animals that have low blood pressure (hypovolaemia), or horses that have endotoxemia. The glucose levels of sick young foals are especially critical because they quickly consume their own reserves of glucose.
Electrolytes
Electrolytes are ions such as potassium, chloride, sodium, calcium, and magnesium that are necessary for the proper function of cells. Electrolytes are important for the normal function of cells. Their levels might fluctuate in unexpected ways, which can be life or death in some cases. For foals, this is particularly true since they are extremely sensitive to variations in salt levels. It is common for horses that are kept on fluids for extended periods of time without eating to require potassium supplements.
Viruses
Your horse’s blood may be checked for viruses, the most recent of which being the Hendra virus, which is now in the news. There is, however, a lengthy number of additional viruses, including the Herpes virus, the Ross River virus, the Kunjin virus, the Rotavirus, and the Coronavirus, to mention a few examples. The difficulty is that we cannot request a ‘virus test’ that will screen for any and all viruses; rather, we must request a particular virus test for a specific infection, which can be difficult.
We may be able to detect what sort of microbe is causing the problem in your horse with the use of the CBC and biochemistry tests, as well as your horse’s clinical symptoms.
There is no direct therapy for viruses, only supportive care, and this is the only option available.
Hormones
We can also check for specific hormone levels. When insulin levels are high, this indicates the presence of the Equine Metabolic Syndrome, when ACTH levels are high, this indicates Cushing’s syndrome, and when oestrone sulphate levels are high in a gelding, this indicates the presence of an abdominal testicle that has become lodged in the abdomen.
Drug Screening
Finally, drug remnants in your horse’s blood can be detected and examined. The Equestrian Australia organization, for example, conducts drug testing at tournaments for drugs such as phenylbutazone, local anesthetic, tranquilizer and sedative. These can also be checked for during pre-purchase inspections if the customer so desires. Some of these drugs can be found in the body for many weeks after usage, while others, such as anabolic steroids, can be identified for much longer periods of time.