Current News

Alsike Clover Toxicity in Horses

Hay or pasture containing a large percentage of alsike clover is generally not recommended for horses.  Why is this?  What are the symptoms of alsike poisoning?  Why is it that some horses seem to be able to eat alsike with no ill effects?  The confusing aspect of the disease is that none of these questions have straightforward answers.  Firstly, the compound that causes the toxicity is not known for sure.  Secondly, the symptoms vary and thirdly, susceptibility seems to depend on the area where the alsike is grown and the individual horse.

The most common symptom of alsike clover poisoning is photosensitization or a reaction to light.  The real problem, however, which is not so readily observed, is liver damage.

The photosensitization is not caused directly by the alsike, but rather is a secondary problem.  Dr. A.A. Seawright has summarized the literature concerning photosensitization.  Alsike clovers may contain some compound, possibly an alkaloid, which causes liver dysfunction.  If this cirrhosis of the liver is allowed to continue, death may result.

The plant material that the horse eats contains chlorophyll.  Bacteria in the intestinal tract change the chlorophyll into another substance, phylloerythrin.  This is all quite normal.  In an animal with a healthy liver, the phylloerythrin is removed from the blood by the liver, and excreted in the bile.  However, in an animal where the liver has been damaged, it cannot pick up the phylloerythrin.  It then is carried by the blood and deposited in the skin cells.  When light of a certain wavelength is absorbed by the skin it reacts with the compound, damaging the cell and causing inflammation and redness.  This occurs only on areas unprotected by thick skin, hair covering or pigmentation, such as in black skin.  Therefore, liver damage may be present without any signs of photosensitization.  Some horses may die within 24 hours of alsike consumption.

Symptoms of Photosensitization:

·         Lining of eyelids, or conjunctiva, become red and swollen

·         Inflammation and lesions of the muzzle, mouth, tongue, eyes, eyelids and ears, with discharge from the lesions

·         Jaundice

·         Nervousness

·         Digestive disorders; “off feed”

·         Brownish urine

·         Clay-colored feces

These are all possible symptoms; animals may show all of these or none.


If you notice symptoms that you suspect indicate alsike clover toxicity, remove horses from pasture and change their feed.  Contact your veterinarian to obtain a correct diagnosis.  There is no specific remedy, but treatment may combat secondary infections.  Some relief may be obtained by keeping the horse in a dark or shaded area.

If your only available pasture has alsike clover in it, you may wish to remove it or reduce alsike clover content in the forage.

A quick method for identifying different clovers

Identification of the different clovers used for forage can be difficult at times because they all display similar features.  The quickest method of identifying the different clovers is by comparing where the flower appears on the plant.

White Clover is low growing white and tall growing ladino clover have a white flower that terminates a single stalk coming from the above-ground stem (stolon).  The leaflets are also found on separate stalks from the stolon

Alsike clover flowers are usually pink and white in color but can be darker depending on growing conditions.  The flower stem originates from the same point off the main stalk as separate leaflet stems.


The Pioneer Spirit

Steven M. Haugen,DVM

33845 SW TV Hillsboro, OR  97123

Care Credit

We will soon be offering Care Credit.  We will offer the 6 months with NO interest plan.  You must apply and be approved prior to the services being done.

This plan requires minimum monthly payments.  If paid within the 6months there is no interest but if not paid within the 6 months there will be interest assessed from the purchase date.

A lot of places are now doing this program.  For more information or to apply go to

New Things Here at Pioneer Vet

We now have a new Ultrasound Machine.  This machine is a diagnostic ultrasound that is much improved for tendon, ligaments and joints.  It still has the probe for reproductive work but is more portable and light weight than our last one.  I bought my first ultrasound machine in about 1984 or 1985.  It was a good machine and at the time nobody in this area had one and ultrasound didn’t exist.  There was no such thing in Vet School, again it didn’t exist.  It was exciting and soon we began looking at everything we could.  We looked at lameness problems and I was told by Colorado State that you couldn’t ultrasound tendons but we were doing it.  Veterinarians were sending each other pictures and ideas of what they were doing and seeing.  Now we look at reproductive, tendons, joints, eyes, hearts, colics and have established normals and of course we realize we still don’t understand it all.  I Ultrasound my own fractured knee and hip and can see the progress the cold laser makes.  I am ultrasounding my skull and brain but haven’t seen anything too remarkable.

As for a treatment or therapeutic ultrasound we have a therapeutic ultrasound we can rent fairly in-expensively for sore backs, hips, tendons and torn muscles.  We can rent it with a Veterinarian’s or Chiropractor’s prescription also.

Volume 2 Issue 7   503/648-6472

April 2012



He-Max is a liquid Vitamin high in B-Vitamins and Iron for the treatment and prevention of anemia in horses.  I have been looking for something since Visorbin went off the market that I felt would be effective for treating anemia in horses.  Columbia Equine has been using this product and feels it is working well.  We now carry this product but I still like Lixotinic for Liver Disease horses because it has a Liver faction that the horses don’t have.

Target IR or target insulin resistance, is a Vitamin designed for horses that are on grass hay.  Loyd, Inc makes the thyroid powder that we have been using and they developed this to meet requirements of horses with metabolic diseases such as hypo-thyroid and insulin resistance horses.  These horses are often on grass hay and no grains but it could apply to any horse primarily on grass hay.



New Face at Pioneer Vet

Greetings and Salutations!

My name is Sarah Cyders and I am very excited for the opportunity to get to know both all of you and your horses. I have loved horses since I was old enough to hold a stuffed pony. I grew up in North Portland and was unable to live the dream of horse ownership until relocating to Scappoose in 1995. I bought my first horse soon after and have owned horses ever since. I currently own two beautiful draft cross geldings and live in Cornelius.

I began learning to trim my own horses early on when my first horse hated male farriers and there were no female farriers to be found. I began studying barefoot eleven years ago and decided to take my horses bare. I started trimming horses for friends and co-workers here and there and becoming a farrier seemed to be a likely next step for me. I became a Certified Barefoot Hoof Care Provider and have built up a thriving business in the area.

In addition to trimming horses, I am currently a full time Pre-Veterinary Medicine student and this spring I am completing year four of my Pre-Vet requirements at Portland State University. I plan to apply to Oregon State’s College of VeterinaryMedicine for admittance to become a large animal Veterinarian .

I have enjoyed the opportunity to work as an assistant to Dr. Haugen both to learn first-hand the daily challenges of being a Vet, and also to expand my knowledge in routine and emergency care. It is my privilege to join the staff with Phyllis and Suzanne, who have made me feel very welcome. I look forward to getting my hands dirty, my brain full, and to meeting the many clients of Pioneer Veterinary Services.

Sarah Cyders

The Naked Hoof    



New Hyaluronic Acid (HA)

Hyaluronic Acid (HA) is injected into joints to increase the synovial fluids lubricating properties and to activate tissue repair in articular cartilage.  We have been using some form of HA since about 1984.  This drug has never been designed for those bone-on-bone, end-stage or severely degenerative joints where the cartilage is gone.  However, Dr. Mark Revenaugh is participating in a study that uses a new cross linked (thicker binding) HA that stays in the joint longer and may work on those bone-on-bone arthritic horses. 

You need to have your horse blocked to the specific joint that is causing the problems and rechecks to follow-up on the injection.  If interested call us or Dr. Revenaugh’s office at (503)632-9151.

Dr. Revenaugh also has a MRI machine that can help with diagnosing lower leg problems.  He can get up to the knee and hocks on horses.



New Products

Healing Salve: Can be applied to wounds and abrasions to promote healing.  You can also use it as an anti-fungal and anti-itch salve.  It is 100% All Natural.  Comes in an 8 oz jar.

Chlorhexidine 1% Ointment:  It is just like the name brand Nolvasan Ointment that has been discontinued and is no longer available.  Comes in an 8 oz. and 16 oz. Jar

Excede Antibiotic: Is a two dose antibiotic that is given IM every 48 hours.

Dormosedan Gel: Is an oral gel sedative that you put under the tongue.  Works well for farrier and/or vet work on those more difficult horses.

White Lightning Soaking Boots and Solution:  We are now caring these products for White Line, Hoof Cracks, Thrush and those difficult to treat foot problems.

Super Pro-Biotic:  These pro-biotics in this formula we are caring are the most powerful available and are resistant to most antibiotics.  This product is designed to restore normal intestinal flora, build up on the colon wall, and help to regulate food absorption.


Washington NOW Requires a Health Certificate

Even if you are only going into Washington for the day or even a couple hours you HAVE TO have a Health Certificate…  Your options are a certificate that is good for 30 days or a Passport that is good for 6 months.

The Passport does require that you fill out some info on the back of the passport and send to the state at the end of the 6 months or after your last trip if sooner.


Testing for Equine Herpies Virus (EHV-1)

            You can do a couple of different test for the Herpies EHV-1.  There is a Blood Test and a Nasal Swab Test.  Dr. Haugen has talked to Dr. McKenzie @ OSU regarding the different tests for EHV-1 and Dr. McKenzie says the Blood Test is her test of choice.

            If you are concerned that your horse may have been exposed to this virus we can draw a blood sample and send it to the lab for testing.  If you want the Nasal Swab Test it cost the same. Both tests take 2-5 days to get results.