Spring 2008 Newsletter

SEVS News                               

Dr. Jeske Noordergraaf

Welcome to another spring newsletter from Sunrise Equine Veterinary Services.  It has been a very long and cold winter and some horses have been suffering as much as we have.  We have seen a preponderance of horses with laminitis or colic.  Our thoughts have been that horses are reluctant to move as the ground is so hard and icy and the weather is so cold.  The horses are not burning many calories moving around and the circulation isn’t being stimulated by activity leading to these problems. 

Several events are coming up this spring.  First, we are having a speaker who will give a presentation on stomach ulcers in horses on March 24^th in the evening. We have learned that any horse under stress can develop stomach ulcers so this is a big concern for show horses and sick horses. Even if you don’t think that your horse is stressed, come, enjoy dinner with us, meet other local horse lovers and learn. Our annual Coggins clinic will be held on Saturday, April 19^th.  

Worms are a big concern for horses.  Read about the resistance that parasites are developing to our current dewormers in an article in this newsletter.  To help with this resistance problem, we are recommending doing more fecal exams.  At our upcoming events, we are offering fecals at a very reduced price to help you determine how effective your deworming program is.  All we need is a small amount of fresh manure to determine both the types of parasites your horse has and the number of parasites. 

We are approaching our busy season.  Please call early to schedule your appointment so your horses is protected with current vaccinations and Coggins results are up-to-date before beginning trail riding or showing.  Coggins tests that are in the office by Wed afternoon will have results by Friday at noon.  Other items included in the spring tune-up are:  vaccinations, dental work, sheath cleaning,  deworming or fecals and wellness exams to discuss any concerns you may have with your horse. 

We will have assistants riding in our trucks with us part of the time this spring and summer.  In the office we will have Sue, Julie, Deb and Robyn to help with scheduling and answering questions.  Dr. Emily Steele, Dr. Kirsten Voigt and I are all looking forward to seeing you either at your barn or ours. We appreciate your horses being caught before we arrive. 

Thank you for your continued support and for recommending us to your friends.  We hope to see you on the trails, too.

Items of Interest

We now offer the latest in Digital X-Ray !

 The advantage is that the images are higher quality, the results are instantaneous and we can leave a CD for your viewing pleasure!

You can now haul your horse in for an appointment.

Our barn is a great environment for lameness exams, dental work, breeding procedures and routine care.

We also have the capability to board horses overnight for simple procedures and treatments.  Hauling in for an appointment or boarding your horse for care that requires multiple treatments can save you money and the hassle of leaving work early to meet the veterinarian at your farm.

Intestinal Parasites Are Becoming Resistant!!

Jeske Noordergraaf, VMD 

Horses are a lot of work to take care for but horse owners obviously think that it is time well spent and enjoyed.  Along with many other horse owners, I prefer cleaning the barn to cleaning my house.  Are my horses more appreciative than my family?  Maybe not, but the barn just smells good.  I don't mind scooping manure at all but seeing worms in the manure is unpleasant especially if the worms are roundworms or ascarids and you were planning on spaghetti for dinner. 

Intestinal parasites are harmful to horses.  They can cause colic, weight loss, unthriftiness, and make the horse rub its tail.  Regular deworming is very important but how do you know if your program works?  Fecal egg counts determine what type of eggs your horse is shedding and how many of each is present.  At a recent seminar that I attended the presenting veterinarian discussed resistance.  The drugs we have are no longer as effective since intestinal worms are adapting and unfortunately there are no new drugs ready to be released.  The recommendation is thus to do more testing to determine if there is a problem along with pasture management and knowledge of the parasite lifecycle. Horses do not need to be 100% parasite free as they do develop some resistance.

There are eight common types of intestinal worms in horses: roundworms, small strongyles, large strongyles, tapeworms, pinworms, bots, lungworm and threadworm.  Roundworms tend to be a problem in the young and usually by 18 months of age the horse has developed resistance and it is then unusual to see  these passed after deworming.  The main clinical sign seen in a horse infected with roundworms is unthriftiness with rare reports of death due to impaction or rupture of the small intestine.  The large adult parasites (up to 40 cm long) reside in the small intestine where they produce eggs that are passed in the feces.   It only takes 10 – 14 days for these eggs to develop into the infective larval stage and foals become infected by ingesting them.  The larvae then migrate through the liver and lungs on their way back to the small intestine where the cycle repeats itself.  The entire cycle takes 3 months to complete.  To stop this life cycle, foals need to be dewormed to kill the adults parasites before they start passing eggs which would then be available for other foals of the same age or succeeding generations.  It is extremely difficult to remove the eggs that are already present in the pasture so ideally, young stock should be moved to pastures where only adults have been.  The eggs are very resistant and can survive in the environment for years.  Most dewormers are effective at killing these roundworms. 

In adult horses, Large strongyles are an important problem.  Heavy infections are common in all horses but most common in those 1 to 3 years of age.  Clinical signs include loss of condition and anemia.  The large strongyle larvae spend extended periods migrating through blood vessels and other organs but cause the most serious problems when they are in the cranial mesenteric artery and cut off the blood supply to the intestine.  This is a common cause of colic especially in young horses.  The adult parasites are plug feeders which means that they take big bites out of the intestinal lining as they attach.  Spreading out the manure in a pasture is not recommended as the interior of even scattered manure is moist enough for development to the third stage and then this stage can survive even Minnesota winters. 

Small strongyles cause the most common parasite problem of horses.  The adults reside in the cecum and colon where they feed on plugs of mucosa, leaving small erosions and hemorrhage at each feeding site.  Adult small strongyles also cause the clinical signs of ill-thrift and anemia.  This is the most common parasite we see on farm calls as they can be on our rectal sleeve after doing a rectal exam.  This is when the expression that a picture is worth a thousand words holds true.  These parasites can encyst in the wall of the small intestine for many months before continuing their development into the lumen.  In the wall of the intestine, they cause inflammation and decreased GI motility leading to colic.  The only dewormer effective against the encysted stage is the double dose of fenbendazole for 5 consecutive days. 

Bot flies are visible in the late summer and fall.  The females lay eggs on the horses legs and mane.  The life cycle of this parasite takes about 1 year.  As we all know, these eggs are very sticky. When the horse itches the area with the eggs, the bot eggs end up in the horses mouth where they live for a few weeks burrowing into the mucous membranes of the lip and tongue causing a transient irritation.  The larvae then migrate to the stomach and grow there for 10 months until being passed in the manure where they pupate in the ground.  Stomach bots cause mechanical blockage, colic, or rupture of the stomach wall and resultant peritonitis or infection of the abdomen.  We often wait till after the first frost to deworm with a dewormer that will kill the adults in the stomach but remember that eggs left on the legs are still infective. 

We all blame Pinworms for a horse rubbing its tail.  The female worm lays eggs around the anus which cause the itchiness.  The egg masses can be seen as yellow/grayish streaks when the tail is lifted.  The infective larva develops within the eggshell 4 to 5 days after the pregnant female has cemented it to the skin of the anus.  Masses of cement gradually dry, crack, and detach from the skin in flakes containing thousands of infective eggs.  These flakes adhere to mangers, water buckets, and walls, thus contaminating the environment of the stable. 

Threadworms are generally just a problem in foals aged 2 weeks to 4 months and seldom persist in animals older than 6 months.  Foals become infected either by nursing as the larvae are in the mares milk or by penetration of the skin by infective larvae.  The signs seen include diarrhea and enteritis and a fecal exam will show a large number of parasite eggs.  The larvae seem to go dormant in the mammary gland of mares and only cause problems for the foals.  Mares can be infected without these eggs showing up on a fecal exam. 

Tapeworms are the most recent target of dewormers.  The horse becomes infected by ingesting forage mites which contain a developmental stage of the mite.  The adults live in the small intestine and cecum near the valve between them and can cause colic as a result of a blockage.  The new praziquantel dewormers are effective for these parasites. 

The last parasite that I am going to mention is the Lungworm.  There are also several other types of parasites but these are less common.  Lungworms are frequently found in fecal sample from donkeys but infection is rarely associated with signs of respiratory disease in this host.  In horses, lungworms can be the cause of chronic coughing.  Infection occurs by ingestion of the infective third-stage larvae while grazing.  These larvae then travel from the intestine via the lymphatics and blood to the lungs where they develop to the adult stage in the bronchial tree.  To reduce the risk of infection in horses, contact with untreated donkeys should be avoided. 

Our recommendation over the years has been to deworm horses every 6 to 8 weeks.  There are no new dewormers ready to be released and thus we must work with what we have.  To keep the parasite load down in the pasture, collect feces frequently.  Fecal collection before parasite larvae have migrated out from the fecal pile is the single most important measure that can be taken to prevent problems.  The next recommendation is to actually test the feces for parasite eggs.  There may be a few horses that have the majority of the parasites and these horses will need to be treated more often.  Management factors such as good stable hygiene and paddock rotation and reserving the least contaminated pastures for horses and foals is helpful.  At the end of the grazing cycle, treatment with a compound effective against small strongyle larvae in the intestinal mucosa should prevent outbreaks during the late winter or the following spring.  One other recommendation is to deworm any new horse that comes to your facility and keep the horse isolated for 72 hours to prevent introduction of anthelmintic resistance.

Take advantage of our reduced cost fecal exams and learn which of your horses are carrying the highest parasite load.

 Suggested Deworming Schedule 2008

April - Panacur Powerpak (Fenbendazole)

            (Double Dose Fenbendazole for 5 days in a row)

         
May - Fecal Exam

June - Ivermectin (Equell)

August - Pyrantel Pamoate (Strongid)

October - Ivermectin/ Praziquantel  (Equimax)

December - Ivermectin (Equell)

February - Pyrantel Pamoate (Strongid)

•We recommend deworming foals at 30 days of age with a double dose of   Panacur  by weight  each day for 5 days  in a row to kill parasite larvae.  Then every other month  with rotating dewormers.

•New horses  with no deworming history - Start with a fecal exam , then  deworm as directed by your veterinarian.

•We carry all these dewormers at our office along with Strongid C2X, the daily dewormer. We recommend a fecal test before and after to check to check your deworming program.

•The purpose for the  Panacur Powerpak is to kill the encysted  larva in the small intestinal wall.  No other dewormer is able to treat these and spring seems to resume their lifecycle.

2008 Vaccination Recommendations

SEVS Barn Seminar

When:   Monday,  March 24, 2008

Where:  Sunrise Equine Veterinary Services

              39318 Poor Farm Road, North Branch

Time:    6:30 p.m.- 8:00 p.m.

Speaker:  Jim Kokett,  Merial

 Join us for a Subway sandwich and refreshments to learn about the  many things that can cause our horses stress and ulcers.    

Jim Kokett  from Merial will be here giving a  presentation on the prevention and treatment of Equine Gastric Ulcers. Horses affected by stomach ulcers may have many signs ranging from weight loss, recurrent colic, diarrhea and sub-optimal performance.   

We are offering $5.00 fecal tests tonight.

(Bring 1 small fresh apple from each of your horses in a baggie .)

EIA Clinic 

When:  Saturday April 19, 2008

Where: Sunrise Equine Veterinary Services

             39318 Poor Farm Road, North Branch

Time:   1:00 p.m. - 3:00 p.m. 

Have your horse Coggins tested at a reduced rate.

 Vaccinations also available at a reduced rate.

 Fecal testing available today for $5.00 !

(Bring one small fresh apple from each horse in a baggie !)

Directions:  From North Branch -  7 miles East on Highway 95 to Poor Farm Road. (1/2 mile east of County Road 9). Turn left (north) on Poor Farm Road.  Sunrise Equine is the 3rd place on the left and is the staging area for the incoming trailers.

Please bring your last EIA form along to assist us with the paperwork!       Thanks!

Special Thanks to Fort Dodge Animal Health

for sponsoring our newsletter

Special Thanks to Fort Dodge Animal Health for sponsoring our newsletter!