Last Friday night, my horse, Rex, got very sick.  We all dread making the Friday night phone call to our vet, but in this case, it was absolutely necessary.
 
A few days earlier, Rex had broken out in hives.  There wasn't one square inch of him that did not have hives.  It had been many years since he last had hives, but "dex" (dexamethasone, a prescription corticosteroid) usually took care of it in 2 or 3 days.  It was now day 3, and he still had massive hives.  He also had bug bites on his tummy and in between his front and back legs, (probably from culicoides), which I had been battling for the past 2 weeks. 

I took him up to the barn to cold hose him.  I put my hand on the inside of his hing leg, and his skin felt like it was on fire.  He did not want to be touched, and I completely understood why.  Then I took his temperature and discovered he had a fever.  It was almost 3 degrees above what is normal for him.
 
As an aside, I believe every horse owner should know their horse's vital signs including temperature. Generally speaking, a horse's temperature range is between 99 and 101. It's important to know what's normal for your horse so you can determine the severity of a fever.  Here's a link to My Helpful Links page where you can download a free chart I put together many years ago summarizing how to check your horse's vitals.
 
Ok....Back to the Rex story....
At that point, I called my vet.  She said she would be there as soon as she finished up her current call.  When she arrived approximately 90 minutes later, she asked detailed questions about the current situation and took Rex's vitals. His temperature had gone up another whole degree in 90 minutes.  Quite frankly, Rex looked miserable.
 
After discussing various options, we decided to give Rex a Serum Amyloid A test.
 
Do You Know What a Serum Amyloid A (SAA) Test Is?
 
Give Me the Short Story....
SAA is a biomarker protein produced in the liver and secreted into the bloodstream when there is inflammation caused by an infection, trauma etc.  In a normal healthy horse, SAA is found in very very low quantities and is not secreted until inflammation occurs.  The normal SAA range is below 20 mg/L.  (milligrams per liter)  New devices enable your vet to test your horse's blood for the presence of SAA stall-side and get the results in about 8-10 minutes.  This is in contrast to sending blood off to the lab to be tested for other infection markers that can take longer to show up.  Research is ongoing to determine if and when SAA testing will supplant some forms of more traditional blood testing and when each is appropriate.

A Picture is Worth a Thousand Words....
SAA Production and Response (image by Tridelta Development Ltd)

Reference 1:  Tridelta Development Ltd website

Give Me The SAA Geeky (but not too geeky) Details....

SAA is a member of a group of proteins called Acute Phase Proteins which are thought to be part of the body’s basic first line defense against infection, disease or trauma. In response to a challenge by, for example an infection, the body sends chemical messengers to the liver which then produces and releases SAA into the bloodstream to help fight off the challenge.¹  Researchers have discovered that when there is an infection or challenge to the immune system, SAA levels begin to rise almost immediately... and they can rise to levels hundreds of times above normal.  SAA is extremely sensitive to the onset, duration, and end of the disease process. 
​
The SAA test is a simple blood test performed stall-side with a reader that is about the size of a smartphone.  The device is pictured above.  It takes about 8-10 minutes to get the results.  That means your vet will have additional valuable information about what is going on in your horse's body very quickly and can start treatment immediately.  SAA is normally present only in very low levels. As mentioned above, in a healthy horse, the normal range of SAA is below 20 mg/L (milligrams per liter.)  In response to a challenge, however, SAA is produced in very high levels often 600, 800 or even 1000 mg/L.
 
So, What Were the Results of Rex's SAA Test?
2150!!  (Yes, I did say below 20 was normal.)  In case you're wondering, I'm not missing a decimal place in the 2150. It was two thousand one hundred and fifty.  Needless to say, we started treatment immediately!  By the following morning, Rex had improved greatly.  I am happy to report that 10 days later, Rex is feeling almost 100%.  Phew!!

The Bottom Line.....
There is still much to be learned about SAA and its potential uses in identifying various diseases and medical conditions much earlier than was previously possible. Research is ongoing to determine if and when SAA testing (in horses, humans and other animals) will supplant some forms of more traditional blood testing and when each is appropriate.

• Here's a link to a great SAA Q&A in TheHorse.com
  
• You can also Google Serum Amyloid A and/or speak to your vet if you want to learn more.

Has your horse had an SAA test?  What happened?  Share your story below or on our Holistic Horse Bodyworks Facebook page.

Since this blog is personal, I want to say a BIG thank you to my vet for coming out on a Friday night and to my two good friends and barnmates who stayed with Rex and I and provided excellent support!  I also want to thank the barn owner and the barn manager who helped me care for Rex and were my eyes and ears in between my multiple visits per day taking his temperature and monitoring him.  I owe all of you big time!  It truly takes a village!!  

Q1 Answer: Yes.  Many cases of colic are actually associated with parasites.

Q2 Answer: The correct answer is E.  75% or more of saddles do not fit the horse they are used on.

Q3 Answer:  The average adult horse resting heart rate is 30-40 beats per minute.

Q4 Answer:  This is a trick question!  Horses do not have a clavicle or collar bone.

Q5 Answer:  The top 10 most toxic and poisonous plants for horse are:

• Braken Fern
• Tansy Ragwart
• Johnsongrass/Sudan grass
• Hemlock
• Locoweed
• Oleander
• Red maple trees
• Water hemlock
• Yellow star thistle/Russian knapweed
• Yew

According to Anthony Knight, BVSc, MRCVS, plant toxicologist from Colorado State University, these are the 10 most dangerous plants for horses.  Here is a link to great summary of his study in EQUUS magazine, complete with pictures of each plant, a description of the danger posed, signs and what to do if your horse becomes poisoned.

Q6 Answer:  The average, healthy adult horse that weights 1000 lbs should consume approximately 5-10 gallons of water per day if the horse lives in a temperate climate and is not working. This works out to about a half gallon to a gallon of water per hundred pounds of body weight. If the horse’s workload increases or the horse lives in a hot OR cold climate, the need for water increases. Horses with certain medical conditions may also need more water. Here is a link to great article on horses and water consumption.

Q7 Answer:   Yes.  According to a study conducted by Dr. Ava Frink, DVM, muscles and connective tissue respond to overuse by shrinking and tightening. Its response to underuse is much the same. Stiffness can result in injury, lead to inactivity, and eventually speed up the aging process of the musculoskeletal system.  

Q8 Answer:  In the equine world, laminitis and founder are often used interchangeably, but there is a difference. Laminitis is a condition that can lead to founder if the case is chronic.
 
Laminitis occurs when the soft laminae tissue in the hoof become inflamed and swell. There can also be lack of adequate blood flow. Swelling of the laminar bond between layers of the hoof lead to the initial phases of acute laminitis. As the swelling increases, so do the problems for the horse.
 
Chronic inflammation of the laminar bond can result in a bone in the foot, called the coffin bone or pedal bone, separating from the hoof wall. The laminae hold the coffin bone in place and attach it to the hoof wall. Inflammation and/or death of the laminae means they can no longer do their job of holding the coffin bone in place. As the condition progresses (or if left untreated), the coffin bone can begin to rotate and slip downward toward the sole of the foot and even through the sole of the foot. When a horse’s coffin bone rotates downward or sinks, the horse has entered a stage of chronic laminitis or founder.

Q9 Answer:  C is the correct answer.  The purpose of shims is to bring the saddle to a level and stable position.  Therefore, the shoulder that is less developed, more hallow or “smaller” is where the shim(s) should be utilized.

Q10 Answer:  The correct answer is B.  The “two finger” test is the general rule. This means riders should be able to stick two fingers in between the leather and the horse’s nose.  A tight noseband can cause both physical and psychological damage to the horse. Studies are ongoing to determine the extent of the damage.

The question of which vaccines your horse needs and how often to vaccinate him/her is complex. There is a growing debate on this important topic.  Are horse’s being over vaccinated, and is this causing harm?

Publication of a research study conducted by Oregon Health & Science University (OHSU), (a world renowned hospital and research center), suggested that adults only need a tetanus shot every 30 years, not every 10 years as is current practice.  In their paper, the researchers stated there was very little data to prove or disprove the current “every 10 years” practice.  Study data indicated adults remain protected for at least 30 years. 

This research study and the fact that there are few, if any, vaccines that are recommended annually for humans (and equine and human immune systems function the same way) got me thinking, once again, about all equine (and canine) vaccinations, not just tetanus.  Why are most horses vaccinated annually for the “core 4” if not more?  Is there data to support this vaccination schedule?

Current Guidelines
Let’s take a step back.  The American Association of Equine Practitioners (AAEP) guidelines suggest most horses should be vaccinated annually for Tetanus, Eastern/Western Equine Encephalomyelitis, Rabies and West Nile Virus.  Additional risk-based vaccines may also be given such as Strangles, Flu, EHV and Potomac Fever to name a few.  Of course, the AAEP guidelines state that vaccine decisions should be made in consultation with the owner’s vet, though a majority of horse owners and vets follow the AAEP recommended guidelines.   

How Do Vaccines Work?
Here is a quick, high level and easy to understand overview of how vaccines work provided by the Centers for Disease Control (CDC).

1) What is Immunity?

When disease germs enter your body, they start to reproduce. Your immune system recognizes these germs as foreign invaders and responds by making proteins called antibodies. These antibodies’ first job is to help destroy the germs that are making you sick. They can’t act fast enough to prevent you from becoming sick, but by eliminating the attacking germs, antibodies help you to get well.

The antibodies’ second job is to protect you from future infections. They remain in your bloodstream, and if the same germs ever try to infect you again — even after many years — they will come to your defense. Only now that they are experienced at fighting these particular germs, they can destroy them before they have a chance to make you sick. This is immunity. It is why most people get diseases like measles or chickenpox only once, even though they might be exposed many times during their lifetime.

 2) Vaccines to the Rescue

Vaccines offer a solution to this problem. They help you develop immunity without getting sick first.

Vaccines are made from the same germs (or parts of them) that cause disease; for example, polio vaccine is made from polio virus. But the germs in vaccines are either killed or weakened so they won’t make you sick.

Vaccines containing these weakened or killed germs are introduced into your body, usually by injection. Your immune system reacts to the vaccine the same as it would if it were being invaded by the disease — by making antibodies. The antibodies destroy the vaccine germs just as they would the disease germs — like a training exercise. Then they stay in your body, giving you immunity. If you are exposed to the real disease, the antibodies are there to protect you.

Why Are Vaccine Boosters Needed?
A single dose of some vaccines provides lifelong immunity to most people, while other vaccines require additional doses, i.e. a booster, in order to maintain immunity.  Sometimes boosters are needed because the immune response “memory” weakens over time.  A booster is like a reminder to the body’s immune system.
 
Vaccine Reactions
Vaccines can cause reactions in humans and in horses.  Reactions to vaccines can range from very minor to severe and life-threatening.  Equine vaccine reactions can include, but are not limited to:

• Injection site swelling—for days, weeks or even months
• Fever
• Lethargy
• Lameness
• Swelling in the limbs
• Muscle stiffness and soreness
• Anaphylaxis  (rapidly advancing life-threatening allergic reaction)

Some of these reactions can require extensive treatment and convalescence, while others dissipate on their own.

Are Annual Boosters Needed For Horses? What is the Scientific Data Supporting This Schedule? 
Many vets firmly believe that annual vaccination is necessary. However, there is curiously little research data to support this schedule which is unfortunate.  More research funding is needed.

In recent years, there has been a small but growing number of vets (and horse owners) that are rethinking the annual vaccine protocol.  This is due to mounting evidence that over vaccination is a problem due to the increasing number of negative side effects, some of which can be permanent, broadly called vaccinosis.

Here are links to 4 articles from vets who are rethinking the annual vaccination protocol.
Rethinking Vaccines, By Dr. Joyce Harman
Vaccination Protocol, By Dr. Mark Depaulo
Rethinking Vaccines, By Dr. W. Jean Dodds (article part one)  (article part two)

Each article offers a detailed explanation regarding how vaccines work, as well as the benefits, risks and side effects. They all also discuss the lack of data supporting the annual guidelines and suggest alternative ideas regarding the timing of vaccines, which vaccines to vaccinate for and titers testing.  Titers testing is a laboratory test measuring the existence and level of antibodies to a disease in the blood. Antibodies are produced when an antigen (like a virus or bacteria) provokes a response from the immune system. This response can come from natural exposure or from vaccination.  The amount and diversity of antibodies correlates to the strength of the body's immune response.  That said, titers teting has limitations and a positive or negative titers test is not a clear cut answer as to whether your horse or dog is protected.

Some Questions to Consider When Deciding on A Vaccination Schedule and Consulting with Your Vet

1. Is your horse a performance horse that attends a lot of shows/events, or more the stay-at-home type?
2. Does your horse have their own acreage with a small number of stay-at-home horses, or is your horse boarded at a big facility where there’s more risk of exposure?
3. How old is your horse?
4. How is your horse’s overall health?
5. What diseases are prevalent in your area?
6. Has your horse had a previous vaccine reaction?

 
Bottom line....
My purpose in writing about current common vaccine practices and thoughts is to enable a healthy debate and free exchange of information so each horse owner can make an informed decision about what is best for their horse’s health and well-being.  Vaccines can be a very beneficial tool to fight disease.  I am in no way suggesting that horse owners should stop vaccinating their horses.

There is no one size fits all answer as to how often your horse needs to be vaccinated and with what vaccines.  Sadly, there is little research on this complex issue.  So, stay informed on this topic and talk to your vet and other vets too!

What is your opinion?  Do you think horses are being over vaccinated?  Why or why not?  Has your horse ever had a bad reaction to a vaccine?