Every time we change clocks around here Dr. Lacher starts to go on and on about checking fecal egg counts on our patients.  It always makes me wonder what happens when they clean my litter box but Dr. Lacher told me she doesn’t work on cats, only snuggles with us.  I did get her to answer about fecal eggs counts on horses and thought I would blog about it this week so here goes:

Around the early 1980s a revolution happened in equine parasite control:  Ivermectin.  With the use of this drug, horse owners could easily and safely remove parasites from their horses on a regular basis.  Doses of up to ten times normal would not cause problems and since it was a new class of drug parasites were annihilated.  Horse owners were happy, horses were happy, drug companies were happy and veterinarians were happy they no longer had to tube deworm.

We traveled along in our little universe until the late 1990s thinking everything was great and fine.  Worms were a thing of the past and we should keep our horses healthy by deworming every 6-8 weeks.  Sure resistance could be a problem but we just rotated products and that was that.

And we were wrong, very, very wrong.

Dewormers all have what is known as an egg reappearance period.  This is the time it takes to begin seeing parasite eggs in a fecal egg count after administering a product.  For Ivermectin this is 6-8 weeks, fenbendazole and pyrantel 4-6 weeks and moxidectin 10-12 weeks.  You should never administer a dewormer sooner than its egg reappearance period and ideally it should be at least double that time frame.  So by using Ivermectin too often we were killing off any and all sensitive parasites and only allowing the ones resistant to treatment to survive.  We were creating super worms!

Most of us do not have these super worms on our properties and can avoid their creation through intelligent deworming using fecal egg counts.  And here is where we get back to changing your clock and checking a fecal.  Turns out in Florida we kill off a tremendous amount of the parasite load during our very hot summers.  Parasite eggs cannot survive prolonged temperatures over 85 degrees.  Once temperatures have decreased below 85 degrees for about 7-10 days in a row we have the potential to drastically increase our horse’s exposure to viable parasites!  This means that if we check a fecal now and determine our horse’s parasite burden we can ensure they are treated effectively through our prime parasite season.  By checking their burden again in the spring we can maximize the effects of a final deworming before warm temperatures decrease the need for drugs.  This allows us to deworm only the horses that need it when they need it with the drug they need.

The next way we minimize resistance among the wee beasites is by keeping a low worm burden in our horses.  “Whoa!” you say my horse is not going to have any worms!!  Our horses were designed to have a low parasite burden and do just fine as long as the numbers don’t get too high.  In fact recent research has shown low levels of intestinal parasites to be important in combating diseases of the immune system.  More importantly for this topic, by keeping a small amount of worms around we ensure that resistant and non-resistant parasites breed, creating offspring who are susceptible to our deworming drugs.  So again, fecal egg counts help us identify only those horses with very high burdens and target only them for therapy.   This reduces the number of parasites exposed to drugs unnecessarily.  This is known as refugia for those scientific types who enjoy spending time on Wikipedia.

Fecal egg counts also allow us to check for resistance to drug classes.  When performing counts we always recommend a recheck fecal on any high shedders 10-12 days after dewormer administration.  This allows us to make sure there was a significant drop in egg counts.  If there isn’t, we know resistant parasites are a problem and we can take steps to address this very serious issue.

Deworming has definitely gone from a one schedule fits all to a customized program for you, your horse and your property.  The Doctors and Technicians at Springhill Equine have been great about answering my questions while I supervise from the counter and I’m sure they would answer yours as well!

That’s all from the countertop this week.  May your litter box be clean and your food bowl full!!

In recognition of this year’s theme for our Third Annual Springhill Equine Open House! Hope to see you Saturday, October 8^th from 10 a.m. to 1 p.m.!

Hurricane Andrew was an eye-opening event for Florida horse owners.    Many horses died in their stalls because their barns collapsed around them, fences failed allowing horses to get out on roadways or tangled in the fencing and wandering horses got electrocuted or suffered severe dehydration looking for water sources.  This led to the Sunshine State Horse Council gathering together information on what worked and didn’t work to save lives.  In this newsletter we have pulled together the most pertinent information for our area and given you a place to start planning.

A huge lesson learned was to be prepared!  Assessing your risk level and forming a plan for your animals, your family and yourself ahead of time is key.  There are many fantastic websites such as www.sshc.org/evac/disaster.htmand www.ready.govwhich will help you start.  We face some unique challenges when evacuating our horses.  If you decide to evacuate it must be done early since your horse trailer will become difficult to drive once winds get above 35-40 mph.  It will also be necessary to leave someone to take care of the horses while evacuated and transport all feed and hay needed.  It may be an option to “locally” evacuate your horses to a more secure location.  Checking with local horses show facilities (like Canterbury), neighbors and friends may provide a safe alternative. Many of us have more horses than trailer space so decisions will have to be made about which horses get evacuated and which ones stay home.  These decisions are always easier to make before the hurricane is headed straight for us!

To the surprise of many, the safest place for your horse is in a large, well fenced pasture.  What fencing was best was also surprising.  As it turns out, mesh fences such as no-climb worked best.  Mesh fencing acted as a net to grab debris and wrap it up.  The fence also withstood very strong winds and was still effective at containing livestock.  Board fencing and barbed wire caused the most damage.  Flying debris broke boards, which became flying debris themselves, allowing livestock to escape.   Barbed wire caused numerous horrific lacerations, causing horses to be euthanized.  By giving horses a large fenced area they were able to move around to the safest location and weather the storm there.  Another important tip when setting up your property: ensure pastures are set up to keep horses away from power lines if they come down.

Horses that were found following Hurricane Andrew had to be reunited with their owners.  The importance of animal identification was further highlighted by Hurricane Katrina.  Microchips proved to be the most definitive way to prove identity but only up close.  Rescue personnel found large phone numbers written in grease pen to be the most helpful.  Your phone number on your horse allowed them to identify readily that the horse was owned, who the owner was and the address of the owner.  If area phones were working, rescue workers could then contact the owners.  Because area phones are often down, it is recommended to put a second phone number on your horse of someone who lives out of the area.  There are several ways to get all this information on your horse.  One way is to write everything in permanent fabric marker on a strip of sheet.  Braid this in to your horse’s mane and/or tail.  This can also be done with dog tags.  Writing down all your information on a piece of paper, placing it in a Ziploc bag and duct tapping it to your horse’s halter is another way to keep critical information on your horse.

A few quick things were identified that proved helpful post-disaster:

– Install a hand pump on your well. 

–  As you landscape your property, use native plants. Native plants are used to native weather and are less likely to be uprooted.

–  Get mobile home tie downs to secure vehicles and trailers – in the middle of the largest open area away from trees and buildings.

–  Have a disaster supply kit that includes: flashlight, battery operated radio, extra batteries,  fire  extinguishers, chlorine bleach, blankets, clothing, ready to eat food, first aid supplies, water,  prescription medicines, eyeglasses and cash. Update and check equipment at the beginning of each hurricane season.

–  Have on hand a box packed with halters, leads, duct tape, tarps and plastic, fly spray and animal medical supplies including bandages and medicines. Store in water proof container and secure

–  A two week supply of animal feed and medications should be brought in to the house and
stored in water proof containers

– Photograph or video property and animals, and take film/tape with you if you must evacuate.

Don’t forget – the most important thing you can do to be prepared for disasters:  Attend the Third Annual Springhill Equine Open House this Saturday October 8^th from 10am to 1pm.  We will have information on a wide variety of disasters and Connie Brooks, an internationally recognized Disasters and Animals response specialist.

Florida or Japanese yew can kill your horse quietly in a matter of minutes – it is common to find the dead animal next to the yew. Animals will show nervousness, trembling, ataxia, and collapse will occur as the poison slows the heart to a stop.  Only 6 to 8 oz. will kill a large animal, and all species are susceptible to poisonings (including you people!). Do not plant this anywhere your animals may gain access to, or in a place where clippings may be thrown over the fence to your animals.

Yew

Red Maple

Red maple ingestion causes hemoglobin, the molecule in red blood cells that carries oxygen to the body, to change into methemoglobin, a less efficient form, for reasons unknown. This also results in rupture of the red cells, called hemolytic anemia. This effect is specific to horses. Wilted or dried leaves are the most dangerous (the toxin concentrates as leaves get ready for autumn). Fresh leaves do not appear to cause a problem. Signs of toxicity include dehydration, depression, and change in gum color (blue to brown, also yellow or “icteric”).  Increases in heart rate and respiratory rate are mild, but the urine will become dark red to brown. Death generally occurs 1-5 days following ingestion of a lethal dose.

Black, wild, and laurel cherry trees contain cyanide, which turns the horses’ gums red. This is a result of a decline in oxygen utilization.  Symptoms usually onset 30 minutes to an hour of ingestion.  The most toxic parts of the plant are the leaves and the seeds. One laurelcherry berry can kill a horse, and all animals are susceptible to cyanide toxicity.  There are many other species of plants that produce cyanide compounds, including elderberry, heavenly bamboo, hydrangeas, and various clovers.

Laurelcherry flowers

Oak leaves and acorns contain tannins, the substance that makes the Santa Fe River red.  The redder the leaf, the higher the tannins. Tannins cause kidney damage, making it difficult to form urine and regulate water and electrolytes. Clinical signs include colic, depression, frequent or no urination, constipation and/or bloody diarrhea.  “Oak bud poisoning” occurs when weather damages most available forages, and the budding oaks and acorns are most of what’s left.  In 1985, oak bud poisoning killed over 1,000 cattle in Sacramento, CA when snowfall left nothing but oak leaves to eat. Cattle and sheep seem most susceptible, while horses, goats and chickens are occasionally affected. Pigs seem to be resistant. All species of oak should be considered dangerous.

If it is an ornamental plant, has waxy leaves, seed “pods” of some kind, or berries, it probably isn’t something your horse should be eating. Most notable pods to stay away from include Crotalaria species, a yellow-flowered plant commonly referred to as “rattlebox.”  Ingestion of rattlebox can result in liver failure in the horse. Common signs with chronic toxicity are icterus, and signs of forebrain disease such as a change in attitude with depression, circling, and head pressing.

 Rattlebox

Another dangerous plant tip… don’t ever use black walnut shavings for your horses’ bedding.  It will result in laminitis with even limited exposure.

Thanks for visiting my counter, may your litterbox be clean and food bowl full!

The pituitary gland is a normal part of the typical mammalian brain, sitting at the base of the brain just above the two optic nerves (one from each eye). There are three lobes in the pituitary gland – one of which is the “pars intermedia.” For reasons unknown, the cells in this region begin to increase in size, increase in number, and/or change into a benign tumor – called an adenoma. This underlying change seems to be the primary contributor to Cushing’s disease in the horse, which is different from, say, a dog, who may develop Cushing’s due to a problem in the pituitary gland or the adrenal gland.  The pituitary gland, in both species, regulates the adrenal glands’ production of cortisol (commonly known as adrenaline). It is primarily the effects of cortisol that result in the symptoms seen with PPID.

Symptoms of PPID can vary based on the stage of the disease and specific proteins that are being overproduced by the horse’s pituitary gland. The average age is 20 years, but horses 7 years or older can develop the disease. Ponies and Morgans have a high incidence of the disease. The most commonly recognized sign of PPID in horses is a long, curly hair coat with abnormal shedding patterns.  Another common sign is excessive drinking (considered >25-30L (8-10 gallons) in the normal horse) and/or urination.  Bulging eyes, abnormally located fat deposits, inappropriate lactation, muscle atrophy, and/or weight loss may also be seen. Related problems that can occur in horses with PPID include laminitis, fertility problems, chronic infections or recurrent hoof abscesses, and blindness.  Blindness in horses may occur when growth of the pituitary gland results in compression of the optic nerves.

There is more than one way to diagnose Cushing’s disease in your horse. The “gold standard” test is called the Dexamethasone Suppression Test – it is considered the most reliable.   The horse is given an injection of dexamethasone, a type of steroid.  Then a blood sample is taken approximately 18-20 hours later.  If the horse is not able to reduce his own level of cortisol in response to the steroid we injected (“doesn’t suppress”), he is considered positive for Equine PPID.  This test can be performed with the horse in-hospital overnight, or with two farm call visits. The other test for Equine Cushing’s is a baseline ACTH measurement (a hormone that is produced by the normal and abnormal pituitary). If, at rest, the ACTH is above a certain level, it can be presumed that the excess production is a result of PPID.  These are the two most reliable and commonly performed diagnostic tests for Equine PPID.

While treatment of PPID is not curative, it can significantly improve your horse’s quality of life, ability to fight off infections, and potentially fertility in older broodmares. The most effective treatment for Equine PPID is pergolide powder, given by mouth as a top-dress to feed or via syringe once daily. Sometimes the initial dose of pergolide must be adjusted to fit your horse’s disease severity and response – repeating the above diagnostic tests once your horse is started on pergolide treatment can help determine if the given dose is appropriate. Pergolide treatment costs about $80 per month, and is given for the remainder of the horse’s lifetime. While expensive, it may reduce your horse’s future discomfort, and your future medical expenses related to management of laminitis, chronic infections, or infertility. Other treatment options include cyproheptadine, which is generally less expensive, but seems to show less consistent benefits than what has been seen in studies when compared with pergolide. It has been used in combination with pergolide for the purpose of improving its efficacy. Other important aspects of treatment and management of PPID in horses include a good preventative medicine program (vaccines, deworming, dentals), clipping of the long hair coat in summer, management of infections with antibiotics, corrective farriery for laminitis and hoof abscesses, and maintaining a good body condition with an appropriate feeding schedule.

If you suspect your horse may be affected with Equine PPID, and are interested in diagnostic testing and/or treatment, please contact the office to schedule an appointment. For any further questions about this newsletter, feel free to contact Dr. Lacher or Dr. King by phone or email.

The defnition of senior or geriatric horse is very individual dependent.  Some of our patients are slowing way down at 18 to 19 years, others are being ridden 3-4 times per week and even still showing in to their late 20s.  Many factors determine how your horse handles the years but diet, exercise history and genetics are very strong components.

I drew from some human research to determine that the biggest reason we slow down as age is fat.  Young adult humans are at maximum muscle mass which slowly declines over the years and is replaced by fat.  Nerve conduction velocity decrease and we lose some ability to move oxygen from our lungs to our tissues.  But I said slow down, not stop.  This means many older horses can continue to compete, trail ride or whatever you wish.

The type and extent of conditioning primarily will depend on several factors, including the age of the horse, training history, body condition, and the main goal of the conditioning program. For example, the amount of training that is reasonable for a 15-year-old horse will likely be considerably greater than for a horse in his mid-20s. However, regardless of age, we need to consider the horse’s training history carefully. There are many eventers, show jumpers, and endurance horses which have sustained a high level of fitness throughout their teen years–those horses appear capable of training and competing at a level not far below that of a much younger horse. However, because they are well-schooled in their respective events, these seasoned campaigners often can remain competitive with a lower training volume. This helps reduce excessive wear and tear on the musculoskeletal system.

The situation will be much different for the middle-aged and older horse which has received little exercise for a number of years. A much more cautious approach to conditioning is required.  As well, there is an impression among riders and trainers that those horses take more time to attain fitness compared to the youngsters.  Therefore, you must start out very gradually, be patient, and closely monitor your horse for signs that indicate you are overdoing it.  For horses of any age, injury and lameness can occur when the training volume is increased rapidly.  Carefully palpate tendons and ligaments of the lower limbs for signs of heat, swelling, and pain.

Obviously, the level of training also will depend on whether or not you are aiming to compete your horse. This is a reasonable goal for the teenager, but (in most cases) less reasonable for the horse in his mid-20s. More realistic is a program of regular light exercise that helps maintain body condition and muscle tone, and allows the horse to be used for trail riding or similar tasks. This is a win-win situation–regular exercise will help prevent or even reverse some of the age-related changes in muscle mass and strength, and will also improve your horse’s quality of life. Daily turnout is another way to ensure that the horse receives regular exercise, and is certainly important for maintaining good spirits.

The most common limiting factor in older horses is chronic lameness.  It’s a good idea to have one our Doctors examine your older horse before putting the previously idle horse back into work. Lameness associated with foot pain is common in older horses, and some medication as well as special shoes might be necessary.  Pain associated with degenerative joint disease is common; again our Doctors will be able to identify these problems and make recommendations concerning pain relief and exercise programs.

It is advisable to schedule regular veterinary check-ups, particularly for horses in their 20s. Keep a close eye on the joints, tendons, and ligaments of the legs–any stiffness or swelling might signal the recurrence of an old problem and the need to moderate the conditioning program.

Start your conditioning program slow.  Monitor your horse’s response to increased work very closely.  As a guide, do not increase the weekly training distance by more than 5%. Three 10-15 minute sessions per week on the longe line or under saddle might be an appropriate place to begin–the length of these workouts can be increased over the next month. Then, you can add another weekly session and/or begin to increase the intensity of the workouts gradually by inserting some low-speed cantering. Try to vary the workouts as much as possible to maintain the horse’s interest. If possible, include a little hill training–this will help muscles strengthen.

Be cautious during the hot summer months, particularly when beginning training during the summer.  Older humans and animals are often less able to lose body heat during exercise, in part because of a decline in cardiovascular performance and a reduction in sweat gland function.  For that reason, it is wise to limit exercise on very hot days–either shorten the duration of work or reduce the intensity of exercise. In hot weather, actively cool the horse after exercise by applying cold water over the neck and body.  Also allow him to drink a moderate amount of water after exercise to replace fluid losses due to sweating.

Watch your older horse’s weight while increasing workloads.  Some older horses can have trouble absorbing nutrients from their feed.  If your horse is having trouble maintaining weight with an increased work load consider switching to a Senior diet.  With their easily digestible nutrients and higher fat content they are the perfect choice.  Additional fat in the form of vegetable oil can also be added to increase weight.

Hope these guidelines help you keep your older horse in work!