Lunging for Back Strength

In virtually all disciplines peak performance depends on the horse’s ability to drive deeply from the hindquarters, to round and lift its back, and to move freely up front.  The key to beautiful, free movement is a properly conditioned horse with a strong back.  Several things can adversely affect a horse’s back such as a poor fitting saddle, slipping on bad ground, being out of alignment, or improperly conditioned back muscles.  A horse suffering from back pain may experience decreased flexibility and a limited range of motion, and it may exhibit avoidance behavior and other performance-related issues.  If your horse is showing any of these behaviors, it is important to get a thorough examination to diagnose and treat the animal’s problems. The physical examination should include a thorough history, the visual inspection of top-line musculature for symmetrical or asymmetrical muscle atrophy, the palpation of boney spinous pain or back muscle pain, and an evaluation of the horse’s movement in a straight line and in both directions on a lunge line.  The veterinarian may determine that the horse needs further diagnostic assessment that may include x-rays, ultrasound, or the use of other diagnostic imaging tools.  Once a diagnosis is made, a treatment plan will be tailored to the individual horse and may include chiropractic, acupuncture, magnawave, shockwave, injections of the back muscles or articular processes, systemic anti-inflammatories, or muscle relaxers.    After the primary condition is diagnosed and treated, prevention of further back soreness is crucial. Long periods of rest for a horse with back problems are not recommended because this could lead to loss of valuable epaxial muscle tone, to persistent back pain, and possibly slow the horse’s return to work.

Following a tailored rehabilitation and exercise management program is very important to ensure a complete and speedy recovery from a back injury or back pain.  After the initial work up and treatment on the horse is completed by a veterinarian, an individualized rehabilitation protocol for the horse should be prescribed.  Often a painful horse will need an exercise program that involves a “workout” without carrying the weight of a rider or constricting tack.  The key to developing strong back (epaxial) muscles is an effective lunging program.  Such a program requires minimal equipment, and a committed owner/trainer that is willing to follow a specific workout schedule.  An effective lunging protocol requires a neck stretcher (elastic reins), a non-constricting surcingle, a snaffle bit, lunge line, a large area with good footing, and a watch or clock.  The following lunging/back conditioning program was adapted from Dr. Audrey DeClue and Dr. Bob Racich of Lake View Equine Veterinary Clinic in Roberts, Wisconsin.

  1. Week One: Lunge your horse daily with a surcingle set (not tight) and a neck stretcher (elastic reins), and a snaffle bit. Set the reins at the sides of the surcingle or between the horse’s front legs.  Try to achieve a head position PERPENDICULAR to the ground, but don’t demand a head set that is uncomfortable for the horse.  Encourage the horse to long trot in both directions until slightly sweating. To prevent straining tendons or ligaments, be sure to lunge in as large a circle as possible and change directions every 5 minutes.  Cantering is also acceptable, but the main goal is for the horse to move deeply, not fast.  The purpose of the neck stretcher is to encourage the horse to flex at the poll, to lift its withers and to flex its back.  By moving in frame, without a constricting saddle, or the weight of a rider, the horse should develop stronger back muscles.
  2. Week Two: Same as week one; however, after lunging, you may ride the horse lightly, at a long trot and low head set. No lateral, collected, or tight circle work.  Large circles and straight lines are the best.
  3. Week Three: Same as week two; lunge first, then ride until a good warm-up is accomplished, and then progress back to regular work level.

Ground driving with long lines is a good alternative to lunging, but requires a higher skill level by the handler.  A Pessoa Rig will also work in replacement of the neck stretcher.  The neck stretcher (elastic reins) can be purchased from most equine supply catalogs for around $20.  The neck stretcher is a simple aid that ensures proper head and neck carriage and encourages effective use of the back.  The elastic reins have an adjustable piece above the poll, run down through the snaffle bit and hook under the horse’s legs.  The main pressure point is above the poll, which promotes proper neck and back flexion.  Unlike side reins, that put pressure at the corners of the mouth, the elastic reins simply run through the bit and use the mouth as a fulcrum, rather than as a direct pressure point.

The horse should have regular evaluations by a properly trained professional to monitor the response to the rehabilitation exercise program.  A positive response to this rehabilitation lunging program is the improvement of the top line musculature, decreased pain on palpation of the spine and back, and increased suppleness and flexibility during lunging.  A strong, well developed back will lead to a happier horse that is more flexible and able to perform maneuvers with the desired movement when ridden.

Synergy of Animal Chiropractic, Acupuncture and Magnawave Therapy

1+1+1= synergy. Synergy is “the interaction or cooperation of two or more organizations, substances, or other agents to produce a combined effect greater than the sum of their separate effects.

I have witnessed the synergy of the therapies that I use to treat animals in my practice. Namely, I use chiropractic, acupuncture, and magnawave therapies on most of my small animal patients with obscure neurologic conditions. Although I do use each of the therapies individually, I have noticed particularly impressive results when I have employed them in combination.

I want to share a success story with you about Hooch, a 4 year old boxer, who benefited from the synergy of regular veterinary medicine, integrative therapies, and good cooperation on the part of his owners. The first time I saw Hooch, he was not using his left hind leg correctly. He had no proprioception in that foot; thus, he was not bearing weight on the bottom of his foot. His toes were knuckling over and he had sores on the top part of his toes from dragging his leg behind him. The owners reported that two weeks prior Hooch had been playing outside with his housemate, a French Bulldog, and came in non-weight bearing on his left, hind leg. They took Hooch to their regular veterinarian and the X rays showed no broken bones. Their veterinarian suspected a pinched nerve and recommended anti-inflammatories and rest for 2 weeks. Unfortunately, Hooch did not improve during that time frame. At that point, their veterinarian recommended my services for the nerve damage.

On the first visit, I treated Hooch with acupuncture, magnawave and mild chiropractic adjustments since we suspected a pinched nerve. I also recommended some stretching and range of motion exercises that the owners could do at home. Five days later, Hooch came back to my office and we saw some improvement. He was able to correct his toe placement about every 3 steps.The owners were very happy with his progress and we continued with the same therapeutic protocol.

The next week, the owners came back with Hooch whose condition was greatly improved. He placed his foot correctly 90% of the time.

One week later, I saw Hooch again and he actually wanted to run and play!

Hooch still has some movement and nerve deficits in the left hind leg, but he is placing the foot more correctly, the sores on the top part of his toes have healed, and his muscles in the hindquarters are more developed. I recommended short, controlled, leash walks, supervised socialization time with his housemate, and rest for the next month. Additionally, Hooch will receive the three therapies every two to three weeks. Thereafter, assuming Hooch continues to improve, we will maintain him with monthly treatments. Hooch’s progress is a testament to the efficacy of acupuncture, magnawave and chiropractic therapy on neurologic conditions, generally, and the synergetic effects that result when we use the three therapies together.

I am grateful for Hooch’s dedicated owners who are committed to continuing with his therapy and at home exercises. It is rewarding to be able to provide effective therapeutic services for animals, similar to Hooch, with obscure nerve or movement conditions that are difficult to diagnose and treat. The synergistic effects of chiropractic, acupuncture, and magnawave therapies have helped me treat several animals with movement issues. As a veterinarian, it is gratifying to have access to therapies that help restore injured animals’ functionality, fully in some cases, and partially in others, and enable them to lead happy, active lives.

Lameness in horses

Just like human athletes, horses need to be conditioned properly to perform at their peak level.  In the beginning of the season, or after a long time not working, horses should be worked lightly and consistently (about 60 days) to build up their muscles, strength, and endurance. During this “legging up” period, the horses should do a variety of stretching and strength training exercises to properly develop strong muscles, tendons, and ligaments and protect their joints.

Knowing what is normal for your horse’s movement, behavior, or body structure will aid in catching a small issue before it turns larger. Early signs of pain or soreness may start with acting grumpy or unwilling to work. There may be an abnormal swelling, heat or painful area over the body, neck, or legs. They may start refusing to be caught, grumpy when being saddled or stiff going one direction versus another.

One option for owners when their horse becomes lame may include giving the horse a few days to rest in a stall or small paddock. If an area on the body is swollen or has heat, it may respond to cold water therapy by using a hose, or doing topical liniments or poultice. Sometimes a horse will benefit from a few days of anti-inflammatory medication, such as Bute or Banamine. These medications are similar to humans taking aspirin or Tylenol for minor pain.

When the lameness is severe it is time to call the vet. Severe lameness causes the horse to show major signs of pain, such as short striding on a limb, or bobbing its head. Or if a minor lameness persists for a long time and does not get better with a rest period. Sometimes lameness can be so severe that it may end the career of a show horse, especially if that horse is being judged on its movement.  Luckily there are good diagnostics and good therapies that have developed in the past few decades that can help many horses recover from injuries.

A horse in poor body condition, or has poor conformation (body structure) can be more prone to lameness. Their body is not in shape to handle the work load or the poor conformation will put more stress on joints, tendons or ligaments.  A horse’s job can cause lameness in certain areas. Jumping horses can be prone to soreness in their back or hind limbs from the power that it takes to jump. These horses can also be prone to front end soreness from landing on their front legs. Reining, barrel, and cow horses can get sore in multiple areas due to the quick turns, acceleration, and stopping fast. Dressage and Western Pleasure horses can be sore in multiple areas from the strength that it takes to do the collected movement for a long time period. Race horses can get sore in the front feet and fetlocks or knees from extended high speed and poor track conditions.

Good wellness care is the best prevention of lameness. Good nutrition plays a role in proper development of strong muscles and good body condition. An exercise program to properly condition the horse so that it can stand up to the physical demands of the discipline you are asking the horse to perform is also very important.  There are good joint supplements that can help the animal. Routine chiropractic care can help keep the body in alignment and may help prevent a major injury. Joint injections are useful for inflamed and sore joints.

Lameness is a part of owning a horse. Knowing what is normal and that there are good tools available help our horses perform longer and give us peace of mind.

Detecting Lameness

As I stated earlier, assessing the gaits of the equine can be challenging. It takes a lot of practice and a good eye to pick out subtle lameness. Not all lameness is obvious to the average person. First, let’s define lameness as soreness or “off” (subtle) to lame (obvious) in one or more legs. A lame horse will typically “short stride” (shorten swing phase) on the affected leg. Pain causes the horse to spend less time bearing weight on the affected leg.

When I assess a horse, I watch it travel in a circle and/or in a straight line. Hard or firm surfaces are better to visualize subtle soreness whereas; obvious lameness will easily show up on soft ground. I typically observe the horse at the trot and sometimes at a lope/canter. The trot helps most lameness to be seen easily as it is a two beat gait (see last month’s article). Some hind end soreness is better observed at the lope/canter.  I look for 3 key things when watching a horse travel. The length of the stride, how long the feet “hold the ground” and head bobbing.

To assess length of stride, I observe the horse on a circle. I watch all four legs and see how far they reach out in front of themselves before hitting the ground. I look for both front and both back legs to reach out evenly. If a horse is not striding out as much in one leg I will later perform flexion tests on that leg to help pinpoint which joint or area is plaguing the horse. Stifle soreness will generally show up as a shorter stride, dragging of the toe and is more pronounced on outside of the circle.

The second thing I assess is how long the feet “hold the ground”. If the horse is sore in a leg, they typically are quick off that leg in the first phase of the stride to avoid prolonged concussion and compression. For example, a horse that is sore in a hock is quick off it at the lope/canter, especially if that leg is on the inside of the circle. Often times, the hip of the affected leg will hike higher than the non-affected leg or the hock appears to have a “popping” action. I will then flex the hock for one minute and watch the horse travel at a trot, in a straight line on hard ground. This causes the lameness to be more pronounced.

Head bobbing is the third thing I look for with lameness. It can be subtle at the trot or very obvious at the walk. The head will rise when the sore leg hits the ground to shift the weight to the hind end and ease pressure on the front. Hind end lameness will bob head down on sore leg to shift weight to the front end. Head bobbing may be subtle or very obvious depending on the area causing the soreness.

Lameness can be very challenging to diagnose. Often times soreness resolved in one limb leads to the discovery of an issue in another. I often say it’s like “peeling the layers” of an onion. There are many videos on the internet to aid you in visualizing normal equine gait and different lameness.

Equine Biomechanics and Gait Analysis

This article will be the first of two in a series on equine biomechanics and gait analysis. I will first talk about conformation. In order to understand a horse’s biomechanics and assess its motion and gaits, we first must take a horse’s conformation (body structure) into consideration. To evaluate a horse’s conformation for correctness and balance, it must be viewed from the left and right side, as well as from the front and back. A well balanced horse has a better chance of moving efficiently, which results in less stress and lessens the likelihood of injury. So what do we look for when we assess a horse’s conformation?

First, when viewing the horse from the side, the forehand must be balanced with the hindquarters. When the forehand and hindquarters are balanced, the withers are level or slightly higher than the level of the croup, and the center of gravity is located more toward the rear of the horse. A horse’s center of gravity is a theoretical point in its body around which its mass is equally distributed. This point can be found by transecting a vertical line from the highest point of the withers, to the ground and a horizontal line from point of the shoulder to the point of the Buttock.

Most horses must learn to rebalance their center of gravity when moving and when being ridden. How much weight is shifted depends on the horse’s conformation, the rider’s position, the gait, the degree of collection, and the style of performance. The higher degree of collection, the more the horse steps under the center of gravity with the hind limbs. When the forehand is larger than the hindquarters, a horse’s center of gravity tends to be forward. This causes the horse to travel heavily on its front feet. The extra stress on the front end can set the stage for increased concussion to the feet, stress on the tendons, ligaments, and joints, and an increased chance for lameness.

Second, the top line should be smooth, the neck should tie well into the shoulder and the limb angles should be correct for that breed. Interestingly, a horse’s front limbs are not attached to the rest of the spine by a collar bone as are the arms in humans. Rather, a horse’s front limbs are attached to the rest of the skeleton by strong muscles that make up the shoulder “girdle.” The nature of this attachment requires the horse to use its long neck to balance the motion that originates when the hindquarters engage.

There are many other characteristics of a horse’s conformation that can affect a horse’s movement, too. For example, the neck length should be greater or equal to the back length. The hip, from the loin to the point of the buttock, should be at least two thirds the length of the back. If the neck is shorter than the horse’s back, a horse tends to have decreased flexibility and a harder time balancing its motion. Longer-backed horses tend to “hollow” out because they have a harder time lifting, and rounding their backs, and moving their hindquarters underneath their center of gravity. Horses with a shorter hip in comparison to the neck or back tend to lack propulsion/impulsion. 

As you can see, a horse’s conformation is a key component to movement. Some horses cannot physically or really struggle to do what we ask because their conformation won’t allow them. Keep conformation in mind when purchasing a horse for a specific job. It will help both you and the horse be happier.


Biomechanics of Normal Equine Gait

Assessing the gaits of the equine can be difficult. Educating yourself on proper movement and watching multiple horses can help the average horseman to recognize proper or improper movement. The use of video is very useful as the stride is faster than the human eye can process.

I want to talk about the common gaits of walk, trot, lope/canter and gallop. There are some breeds that pace or rack but due to length of this article, they will not be discussed here. Within each gait of the equine is what we call the stride. The stride has two phases. In the first phase the hoof is in contact with the ground. The limb is under concussion and compression forces are occurring during phase one of the stride. Phase two of the stride is the swing phase or movement of the hoof. As the heel leaves the ground, this is called break over.  Then the toe pushes off, called propulsion.

The walk is a four beat symmetrical gait. Propulsion for the walk starts in the hind legs and the front legs follow. For example, right hind, right front, left hind, left front. The walk also contains a diagonal which is difficult to see without video technology. The link at the end of this article shows a great example.

The trot is a 2 beat, natural gait. The legs move together in diagonal pairs. For example, the right hind moves forward with the left front following and the left hind moves forward with the right front following. The trot has variations to the length of stride and rate of speed.

The lope or canter is a restrained form of the gallop. It is a 3 beat gait with the diagonal legs paired in movement. For example, if the horse is traveling to the left, the right hind is the driving leg. The left hind and right front move together for balance, followed by left front and a moment of suspension. The gallop is a strung out lope/canter. It is faster than the lope/canter, a 4 beat gait, asymmetrical and has a longer period of suspension. To visualize the natural gaits of the horse watch the video below:

Chinese Food Therapy for Dogs and Cats



 Cool/Cold DietsWarm/Hot DietsNeutral 
Chinese cabbage
Winter melon
Sweet potato
Bitter Melon
Chrysanthemum, green tea
Green Pea
Brown Rice
Wheat flour
Sesame/Flaxseed OIl
Barley Sprouts (green)
White Rice
Rice Vinegar
Brown Sugar
Olive OIl
Sweet Rice
String Beans
White Fish
Deer Meat






What should I feed my dog?

Our dog owners commonly ask, “What should I feed my dog?” Choosing your pets diet can be a difficult task as there are so many choices. Dog owners should assess the activity level, age and current health condition of their pet before choosing or changing the diet. Some of the newer holistic or whole food diets are not recommended for puppies or geriatric dogs. Dogs with special health conditions may have additional needs that should be discussed with your veterinarian.

The dog is a domesticated ancestor of the wolf. Dogs are carnivores. They were designed to eat meat and thrive best on this type of diet. When the dog ate its prey they also ingested some level of greens or grains found in the stomach. The main stay of the diet should be from a meat source.   

There are basically three choices when it comes to doggy diets.

The first is COMMERCIAL diet. Those are the dry or moist diets that can be found at the grocery or pet stores. They contain grains as their main ingredient, usually corn or wheat. The meat source is typically a meat by-product. Meat by-product can come from a variety of sources but is defined as not fit for human consumption. Depending on the source the protein value can be poor. There is definitely a wide variety of commercial brands but the bottom line is they are usually deficient in meeting your dog’s nutritional needs.

The second choice is a “NATURAL” diet. These diets can also be dry or moist. The biggest and most beneficial difference is that they don’t contain corn or wheat. The meat source is also a better quality. These diets can be found at pet or feed stores. These diets provide better nutrition then the commercial diet. Unfortunately, they are still processed and just because the bag says “natural” on it does not mean it’s the best choice.

The third diet is a WHOLE food diet. They are made with unprocessed foods. They contain quality meat protein source and are very palatable. They are cooked or raw. Whole food diets can be prepared by you or can be purchased. There are many quality whole food diets that can be purchased at some pet or farm type stores. They are generally fresh or frozen. A whole food diet most resembles what a carnivore would eat. The biggest drawback is the higher cost.

As with people, a dog’s health is partially based on a healthy diet. A healthy diet for our dogs is a diet that closely resembles what a carnivore would eat. A natural diet can be supplemented with additional meat, vegetables and eggs. There are numerous whole food diets on the internet or may be obtained from your veterinarian.

Shedding light on equine endeavors

Shedding light on equine endeavors Seminar provides a variety of details on keeing your horses healthy.

Photo by: Wendy Pauly for the TH

shedding-lightChristine Woodford, DVM, gives the audience tips for good horse performance last week. Woodford was the keynote speaker at a horse seminar held in Dubuque.

Horse enthusiasts gathered recently to break bread and learn more about their four-legged friends. Three Rivers Town & Country Store, in Epworth, Iowa, sponsored a dinner and seminar last Tuesday at the Best Western Midway Hotel in Dubuque. About 45 attendees listened to talks on feeding horses and equine conformation (how the animal is built). Katie Kotz, equine and lifestyle specialist for Three Rivers, organized the event. She started the night with a discussion on feeding for weight gain.

While many humans struggle to avoid packing on extra pounds, some horses need to gain weight. Horses might need to improve their condition to look better in the show ring, improve fertility, increase growth or performance, in preparation for sale, or to recover from neglect. Kotz discussed how to assess a horse’s condition using real-world examples. She updated the group on the progress of Lola, a horse the Kotz family is fostering after she was rescued by the Dubuque Regional Humane Society.

Lola was very thin but has been gaining weight. She also had her teeth worked on and is learning better behavior. Kotz was joined by Fran Minnaert, with Land O’Lakes Purina. Minnaert discussed some characteristics of Purina products. After some audience participation on judging horse conditioning and running some feed calculations, Kotz turned the floor over to Christine Woodford, DVM.

Woodford, of Mt. Vernon, Iowa, is certified in animal chiropractic care and acupuncture. These services can relieve stress and pain in horses, similar to the relief they can provide humans.
Woodford spoke to the group about equine conformation and gait analysis. The body structure of a horse is important to consider before studying his gait.

“Balanced conformation is important so the horse can perform well,” Woodford said.
She gave the audience tips on how to examine their horses. The veterinarian also explained how some imperfections could be worked around to make horses comfortable and to perform better.

Woodford also noted that sometimes, a horse just might not be built right for certain activities. But horses are resilient and even a short, stocky pony might be good at going over jumps.

After discussing how horses are put together, Woodford tied conformation to how horses move. A well-balanced horse is likely to move with good rhythm. This should yield a healthy horse, free of pain that might be associated with activities. When something is out of balance, the horse can feel pain. Risk factors for soreness include unbalanced feet, an unbalanced rider, poorly fitting equipment or poor conditioning. Fortunately, steps can be taken to correct many issues. Woodford noted, “Proper foot care is important for horses all year.”

Horse hooves grow year-round but faster in warmer months. Keeping the hooves trimmed and level can help the animal move with balance. Woodford also explained how to examine a horse for lameness (soreness) in their legs. She noted that owners should be sure their horses are trained to be led at the walk and trot pace when they are healthy. If an injury is suspected, a horse will need to be led at these gaits to help the vet determine the problem.

Shedding light on equine endeavors Seminar provides a variety of details on keeing your horses healthy.
Sunday, November 22, 2009

You can view the story by clicking on the link below or copying and pasting the link into your browser:

What bloodwork tells you about your horse

Before you can understand what blood tests are and how they can help diagnose ailments in your horse, it’s a good idea to understand some of the basics about the study of blood–hematology.

Blood tests are a part of veterinary medicine known as laboratory medicine. This branch of medicine is used by your veterinarian–along with physical examination findings–to aid, confirm, or disprove a suspected diagnosis.

When all is normal, most of the components of blood are regulated to a very narrow concentration that varies only slightly from horse to horse. Because of that fact, a reference range for what is normal is available for comparison. Many blood components change in a very predictable way relative to a disease process; therefore, blood tests can be extremely valuable aids in disease diagnosis and determining health status.

The RBC’s main function is to carry oxygen throughout the body, while the various WBCs mainly carry out immune system functions. The red and white blood cells are manufactured within the bone marrow and released into the bloodstream. A small quantity of red and white blood cells are manufactured in the spleen. Platelets are cells that function in blood clotting, and are also manufactured in the bone marrow.

The main protein in the blood is albumin, which is manufactured in the liver, as are other proteins, including ones involved with blood clotting. One example is fibrinogen.

Hematology is used to examine a horse’s red and white blood cell counts. The common name for evaluating these components of the horse’s blood is a complete blood count or CBC. The first test in this category is the packed cell volume or PCV (also called hematocrit). The PCV is the percentage of red blood cells compared to the liquid component of blood, called the plasma. A low red cell mass would indicate anemia, and an increased red cell mass would indicate dehydration (or an overproduction of red cells, which is extremely rare in the horse). There are many causes of anemia (low red blood cell count), including chronic parasitism, blood loss, and chronic inflammation.

This reminds us that a single laboratory test only helps a little with finding the cause of a problem, but when used in combination with other tests and clinical examination, the puzzle can become more clear.

For example, with chronic parasitism there is often weight loss and a low blood protein concentration, and with chronic inflammation there might be low-grade fevers and an increased blood protein concentration. Hemoglobin (the protein within the RBC that contains iron) is normally 10-18 grams per deciliter of blood; a low hemoglobin level in conjunction with anemia would be an indication of iron deficiency anemia. The more common cause of iron deficiency anemia is not dietary, but chronic inflammation or the “anemia of chronic disease” (iron is tied up in the infection-fighting processes of the immune system).

Looking at the total WBC count and the differential can help diagnose various types of inflammation. For example, with severe acute inflammation/infection, the WBC count might decrease with the appearance of immature neutrophils. With more slowly developing or chronic inflammation/infection, the total WBC count tends to increase. With allergic-type inflammation, increases in the numbers of eosinophils and basophils might be noted. The monocyte is the “clean-up” cell of the body, so with chronic inflammation there usually is an increase in the number of monocytes. The WBC count is also useful in determining if you are getting a response to treatment. For example, with a mild/ moderate case of pneumonia, you would expect an increase in the WBC count. If the antibiotic of choice is correct, you would expect–in addition to improvement in the clinical signs–the WBC count to decrease toward the normal range.

If the infection is extremely intense and involves a vigorous bacteria (or virus), the WBCs are consumed rapidly and the total count decreases because consumption exceeds production. With less intense and more chronic infections, the WBC count increases. Blood testing can provide important information, but it almost always needs to be interpreted relative to the clinical examination findings, history, and additional testing in order to arrive at an accurate diagnosis of the problem.


Remember that blood is approximately 60% water and approximately 40% red and white blood cells, with the rest of “blood” containing hundreds of elements, electrolytes, enzymes, and proteins.

We are now interested in some of the components in the blood’s “serum.” The serum is the clear-to-yellowish fluid remaining after the blood sample is allowed to clot and has been centrifuged (spun so that the red cells are removed). The serum contains electrolytes, a variety of proteins, enzymes, and many waste products of metabolism.

The first components measured in a blood chemistry profile are typically the electrolytes sodium, potassium, and chloride. The major function of electrolytes in the body is electrical in nature. For example, when a nerve ending is stimulated, the signal is transmitted to the brain, spinal cord, or muscle by the movement of sodium across the nerve cell membrane. Another example is the collection of cells controlling the trigger for contraction of the top part of the heart (the atria); the signal also depends of the movement of sodium across the cell membrane. Potassium also is closely involved with nerve conduction and muscle contraction.

Electrolytes can also be “lost” through severe or chronic diarrhea or kidney dysfunction.

Another relatively common cause of electrolyte changes (particularly potassium) is a ruptured bladder in foals. The potassium in urine is absorbed into the bloodstream via the lining of the abdominal cavity–a clinical sign of high potassium is an abnormally low heart rate (bradycardia). Electrolyte alterations also can be caused by severe sweating.

The next components often measured in a chemistry profile include calcium, phosphorus, and magnesium. These electrolytes are very important in bone health and muscle contraction.

Changes in these electrolytes can be related to diet, various illnesses, sweating/ dehydration, kidney dysfunction, and other problems. For example, the inflammatory intestinal disease caused by the blister beetle (cantharidin toxicity) is often associated with a decrease in serum calcium.

Phosphorus and/or magnesium increases or decreases are typically associated with extreme dietary imbalances.


Serum protein is an important component of a serum chemistry profile that is typically differentiated into the two “main” proteins (there are many others in relatively small concentrations), the albumin and globulins. Albumin is a protein manufactured within the liver that is mostly responsible for water balance within the blood system. Typical causes of decreased albumin include kidney disease, a decrease in albumin production by the liver, or a malabsorption condition of the gastrointestinal system (sometimes caused by chronic parasitism).

Globulins, or immunoglobulins, are the proteins of the immune system. A common cause of increased globulins is excess production stimulated by chronic inflammation or infection–a long-standing chronic abscess is often a cause of increased globulins Two commonly measured enzymes are SGOT–standing for serum glutamic oxaloacetic transaminase (also called AST)–and CPK (standing for creatine phosphokinase), which are the muscle enzymes.

Elevations of CPK and SGOT are indictors of muscle inflammation–tying-up or rhabdomyolysis. The term “rhabdo” means muscle and “myolysis” means rupture of muscle cells.

The CPK and SGOT are very sensitive indicators of skeletal muscle damage, and they rise in concentration proportionally with the amount of damage. A bit of timing is required in order to obtain the most sensitive results; CPK rises (due to its leakage from muscle cells into the blood system) approximately six to eight hours after the onset of muscle inflammation, and SGOT rises after approximately 12-14 hours. The absolute peak of CPK concentration and the time it takes to return to normal are important indicators of the severity of muscle damage and the response to therapy.

The next compound is creatinine, which is a waste by-product of muscle metabolism that is eliminated very efficiently via the horse’s kidneys. The serum concentration of creatinine is directly related to kidney function; therefore, an increase in serum creatinine is an indicator of renal insufficiency. Creatinine monitoring is useful for a variety of illnesses and conditions that can affect kidney function. For example, severe cases of tying-up can release the protein myoglobin into the blood system, which can be toxic to the kidneys. Monitoring creatinine evaluates how well the kidneys are coping and if additional treatment is necessary.

The next two take a look at liver function. The enzymes SDH (sorbitol dehydrogenase) and GGT (gamma-glutamyltransferase) are associated with liver function. Diseases that cause liver damage or inflammation cause an increased serum concentration of SDH and/or GGT.

Another liver-related compound is bilirubin, which is a compound secreted by the liver into the intestine to aid in digestion. Increases in serum bilirubin concentration can be caused by bile duct obstruction via infection and occasionally even bile stones (gall stones in humans, but horses don’t have gall bladders). Due to the lack of a gall bladder, rises in serum bilirubin concentration can also be caused by relatively short periods of being off feed. Increased serum bilirubin is responsible for the yellowing of skin (jaundice or icterus) often observed with liver disease or hepatitis. Of course, there are more blood tests than can be discussed in this one article, but these are the ones horse owners will most often hear about when they have a sick or injured horse. Remember that some of these tests will need to be done repeatedly over a period of time to see if the levels of various substances in your horse’s blood are rising or falling as an indication of whether he’s getting better, or worse. If you have questions about specific tests done on your horse, ask your veterinarian.