West Nile in Colorado 2016

Horse Positive for West Nile Virus in Weld County

A horse was diagnosed positive for West Nile Virus infection this week.  The virus infected his nervous system and caused it to be unable to stand and move normally.  This virus is routinely vaccinated against in our practice, and if your horse received the routine spring vaccination, should be protected against infection.  It usually takes approximately 3 weeks after a booster for the vaccination to protect your horse.  If you are not sure if your horse was vaccinated this spring, or if you are concerned that a booster may be indicated, please contact our office at 303-841-6006 or click here.



EIA (Coggin’s) Test

What is a Coggin’s test, and why do I need to get one for my horse?  

New horse owners ask about Coggin’s testing frequently, and not having one when you need it is a real headache.  The test checks for antibodies to a particular virus, the Equine Infectious Anemia (EIA) virus.  It is named for it’s inventor, Dr. Leroy Coggins.  The test is regulated by the federal government, can only be drawn by a licensed and accredited veterinarian, and must be run in a federally accredited laboratory.

There are several important reasons to get an EIA test on your horse.

  • Interstate Travel.  Most states require a negative EIA test within 12 months of entry to their state.  Usually a Certificate of Veterinary Inspection (a “Health Certificate”) is also required, and additional requirements vary from state to state.  We have current information on travel to all states as well as foreign countries.
  • Purchase of a new horse.   Our recommendation is that you get a new EIA test run when you buy a new horse, prior to concluding the purchase.  The federal government has specific regulations for managing positive horses, none of which you want to be involved with.  In addition, all infected horses eventually die from the virus, which likely makes the purchase a poor decision.
  • For Medical Diagnosis.  Horses that are depressed, anemic, running a fever that doesn’t resolve, or have other specific signs suggestive of EIA infection will have an EIA test run for diagnostic purposes.

Where do you run the EIA test, and how long does it take?

Our laboratory is federally accredited to run EIA tests, and has been for a number of years.  It is the only local laboratory in Elbert County.  We routinely run the tests several days a week, and results usually take only a few days.  In cases of an emergency (“I forgot that I needed a new one and I’m leaving this afternoon is the usual emergency!”)  we can get while you wait results for you at an additional expense.







This is what an EIA test report looks like.  

Our lab uses Globalvetlink for reporting.  The report comes to you via email as a PDF which you can open and print whenever you like.

Rabies Spreading in Our Area

It appears that the skunk population has spread Rabies virus across the Denver area this year.  To the right is the communication we received from the health department, which urges animals in contact with humans be immunized, or boosted as necessary for Rabies. This is especially important for horse owners because of the transmission risk due to exposure to a rabid horse’s saliva when putting the bit in the mouth or other activities that expose owners to secretions from the horse’s body.  If your horse had it’s booster in the last year, he or she is protected.  We consider the horse to be a “buffer” between wild animals like skunks that are infected and humans.  Call the office today at 303-841-6006 to get your horse’s protection up to date!

Please share the following message with your staff:

Over the last two months, Tri-County Health Department has responded to four incidents involving skunks with confirmed or highly suspected rabies infection in urban areas of the city of Aurora. Three of the four incidents resulted in skunks potentially exposing both humans and pets to rabies. All people and pets have received appropriate follow up and treatment. Thus far in 2016, rabid skunks have been identified in urban areas of Adams, Arapahoe, Douglas and Jefferson counties. The geographic spread of skunk rabies westward through the Denver Metropolitan Area is unprecedented.

Public Health anticipates more incidents of contact between humans or domestic animals and rabid skunks in both rural and urban settings. Your office may be responding to calls or incidents represent a potential rabies exposure, which needs to be investigated promptly. Please follow these steps:

  • Notify Tri-County Health Department at 303-220-9200 within 24 hours of any incident where a domestic animal (pet or livestock) might have had physical contact with a suspect rabid animal, including:
    • Bites by rabies reservoir species (skunk, bat, fox or raccoon)
    • Biting animal is acting sick, abnormal or has symptoms suggestive of rabies
    • Biting domestic pet dies in quarantine
    • Bites by wild carnivores (bobcat, coyote, mountain lion, bear)
  • Contact Tri-Counw Health Department prior to euthanasia if a domestic animal bit a person within the past 10 days and the pet owner is requesting euthanasia.
  • Actively reach out to clients with pets that are overdue on their rabies vaccinations and advise them to come in for a booster dose.

Spring Vaccinations keep your horse healthy!

Spring vaccinations are an important part of keeping your horse healthy. The routine spring vaccine includes protection for:

  • Eastern and Western Equine Encephalomyelitis (also called “Sleeping Sickness”)
  • Influenza (“Flu”)
  • Rhinopneumonitis (also called “Equine Herpes”, EHV)
  • Tetanus
  • West Nile Virus
  • Rabies

These are diseases that are commonly encountered in horses. Here in Colorado, the highest risks of exposure are for West Nile virus and Rabies, as well as the respiratory viruses. We immunize for these in the spring because the encephalitis and West Nile viruses are spread via mosquito bites. Protection persists through the entire mosquito season. If your horse travels to the deep south or the coasts, a second encephalitis booster is recommended in the fall to provide year round protection for these diseases. Rabies vaccine should be boosted once yearly in the horse.

Laminitis (Founder)

“My horse has foundered, what does that mean?”  Laminitis (founder) is a lameness condition that is characterized by the loss of the normal attachment of the hoof to the coffin bone.  There are a variety of causes for this disease including an episode of overeating in the grain room, hormonal causes, and as an after effect of high temperature or severe infection.  Rarely it can be caused by damaged circulation from a wound or other loss of circulation.  When the attachment of the hoof to the bone is damaged, the loss of attachment is usually most severe at the front of the hoof, which results in the most tearing at that point.  On a radiograph from the side of the foot, it appears that the tip of the coffin bone has rotated downward, creating the classic x-ray image of a foundered foot.   Traditionally, severity has been assessed by the number of degrees of difference between the front of the coffin bone and the hoof wall, termed degrees of rotation.  The more rotation, the worse the laminitis episode is thought to be, and the less likely the horse will return to normal.  Occasionally, the damage to the attachment is so severe that the entire hoof becomes detached from the bone, leading to the bone dropping straight downward with no rotation.  These are termed “sinkers”, and the prognosis is much less favorable than a horse with a less severe amount of rotation.

Laminitis can be difficult to prevent.  There are a number of metabolic events that occur when a horse develops laminitis.  In some instances, like the grain overload situation, the horse consumes a large amount of grain and as it passes through his digestive system, the grains ferment, and toxins called endotoxins are released.  These toxins alter blood flow to the foot, cause damage to the lining of the blood vessel in the laminae, and in that way damage the hoof attachment.  Laminitis can also occur after a colic episode, and the endotoxin release from the GI disturbance is thought to have a similar effect.  There are a number of stress related that are involved as well, with cortisone one of the most important.  Horses that have a cresty neck and are obese are at increased risk for laminitis because of a direct adverse effect of insulin on the laminae.  Horses with Equine Metabolic Syndrome have significantly elevated insulin levels continuously, and the effect of increased cortisone in the blood stream makes the insulin level climb higher.  Eventually, a critical level is reached, the laminae are damaged, and a laminitis episode ensues.  Horses that have PPID (Equine Cushings Disease) have persistently elevated cortisone levels in their bloodstream, which causes insulin resistance as well.  Treatment of these conditions involve weight management, dietary changes, and medication to control the PPID if it is present.



This image demonstrates the loss of normal parallel architecture between the front of the hoof and the front of the coffin bone, termed rotation of the coffin bone.  It also shows a very elongated toe and long heel with a steeper than normal angle of the bottom of the bone compared to the ground.  This is described as an elevated palmar angle.  Both issues must be addressed by corrective hoof trimming when managing a laminitis episode.