Controlling Bots

 

Photo Credit: Lauren Langley

Have you ever noticed the tiny yellowish eggs that are laid usually on the inside of your horse’s front legs in late summer, early fall?  Bot flies (adults resemble bees) are responsible for laying those eggs on your horse.  Horses serve as a host for bot fly reproduction.  The bot flies can also lay eggs on the horse’s belly and jawline.  

You may be wondering, how are bot eggs a problem for my horse?  Once the flies start laying eggs on the horse, the horse becomes irritated and reacts by biting or kicking and as a result ingests the eggs.  Once the eggs are ingested, they attach to the stomach wall and develop into mature larvae.  Clinical signs that your horse is infested with bots: difficulty swallowing, ulcers, intestinal obstructions, and other digestive disorders.

Photo Credit: Lauren Langley

What can you do?  Remove the bot eggs if you can with a bot knife.  Be careful not to rub your eyes if you come in contact with the bot eggs which can infect human eyes.  You can also treat for bots after a killing freeze.  Most of the time, a killing freeze kills off the bot flies and that is an ideal time to treat for bots.  Make sure you are selecting a dewormer product that lists bots on the label.  Always consult with your veterinarian when selecting a dewormer product and for the best time to treat.

Introduction to Equine Dry Lots

Managing horses on small acreage can be challenging.  One of the challenges often faced is the need for grazing but being limited on space.  Dry lots can serve many purposes but the main purpose is to have somewhere to confine horses when pastures need time to rest and regrow.  It is important to consider grading and footing when thinking about putting in a dry lot.  Without the proper grade and footing layers, the dry lot will not stand the test of time.  

Follow along with Lauren Langley, Livestock Extension Agent as she introduces the concept and benefits of installing an equine dry lot. You will also hear from two horse farm owners that have installed a dry lot and how it has helped them achieve their goals.

For more information about equine dry lots please visit: https://alamance.ces.ncsu.edu/wp-content/uploads/2021/05/Equine-Dry-Lot.pdf?fwd=no or contact your local Extension Agent for advice.

Getting Ready for Foaling

Mares that are allowed to follow the natural progression of estrus through foaling should start having their foals soon.  The season runs from about May 1 through the summer months.  If you have decided that it would be great to have young horses born on your farm, you may want to take stock of the supplies to have on hand for foaling.

Decide whether a foaling stall or a clean paddock will be used.  In either case, the key word is CLEAN!  If using a stall, be sure that the walls, feeder, and waterer are all cleaned with soapy water and then disinfected.  Ideally, the stall should not be used until the mare is ready to foal.  Add a thick layer of fresh straw bedding just before she starts.

If using a paddock, it does not need to be large.  It should be securely fenced, especially if predators or the neighbor’s dogs are a problem.   Ideally, the paddock should be grass and should not be used until the mare is ready to foal so there aren’t any manure or urine spots.

Here are some things to have handy for when the mare gets ready to have her foal.  This list is not exhaustive, and others may have some items to add, but this covers most scenarios:

-       Stainless steel bucket (clean and disinfected)

-       Access to water (warm water preferred)

-       Towels

-       Soap

-       Gauze

-       OB sleeves

-       Scissors

-       Twine or strong string

-       Enemas – in case the meconium does not pass right away

-       Antibacterial solution for dipping the navel

-       Small container to use for dipping the navel

-       Umbilical clamp or rubber bands

-       Disposable latex gloves (good luck finding any right now!)

-       Obstetric lubricant

-       Blankets

-       Flashlight or headlamp with fresh batteries

-       Cell phone

-       Phone numbers for the veterinarian or a neighbor with experience with foaling

-       Tail wrap or gauze

Be sure to have these items ready before the mare starts to get restless, the udder starts filling out, the muscles over the tail heal and around the croup start relaxing, and/or a mucus discharge is noticed.  Other signs of impending parturition include watching the calendar to see when 340+ days have passed since breeding, milk calcium levels reaching 200 parts per million – mares usually foal within 48 hours of reaching this level - or waxing of the teats.  Again, when this is noticed, parturition will usually occur within 48 hours.

Being prepared will help reduce the potential of problems when the foal decides it is ready to see the world.  As was mentioned above, the operative word is clean to reduce the chance of bacterial infection.  The cleaner the stall, paddock, and checklist items are, the better chance the newborn and the mare have to avoid unnecessary infections or stress. 

Some of the items on the list may not be needed, but if a situation occurs and one or more of those items are needed, there won’t be a delay while the item is found, and cleaned.  Time is critical during foaling and delays add to the stress that is already pretty high for the mare and her foal. Being prepared and avoiding problems help insure that the foal is healthy and the mare recovers quickly.  There are few sights more picturesque than a mare with her newborn foal in a clean paddock. Being prepared helps put that picture together. 

Health Checks

February is a good month to take care of some health essentials for horses.  With the trail ride and horse show season fast approaching, it is a good time to have a Coggins test done.  The Coggins test checks a horse for the presence of Equine Infectious Anemia (EIA) antibodies.  Of course, we want those tests to come back negative, and 99% of them do.  Those test results are important to anyone who will be taking their horses off the farm to locations where horses form several areas will be comingled – places like horse shows and trail rides. Those negative Coggins papers must accompany each horse wherever they go.  As mentioned, February is a great time to get the Coggins test done and get the results back before transporting horses.  The Coggins papers are good for one year, and the process must be repeated.

Some counties hold Coggins Clinics in cooperation with a veterinarian to help folks with just a few horses get the test done.  Check with your county’s NC Cooperative Extension center to see if any of these clinics are scheduled.  There will be two of these held in Granville County this year.  One is on Saturday, February 15, and the second will be on Friday afternoon, February 21.  Call the Granville County NC Cooperative Extension Center at (919) 603-1350 for details.

These clinics also offer vaccinations for the common equine diseases.  The ones most often made available in this area include eastern/western equine encephalitis + tetanus, rabies, West Nile Virus, flu + rhinovirus, and strangles. Check with your veterinarian to make sure that any additional vaccination needs are met as the core vaccines vary across the country.

While at a clinic, or when the veterinarian visits your farm, it is a good idea to get a routine health check for the horse. Most veterinarians will include this if done in conjunction with a Coggins test or when providing vaccinations.  They will also check teeth and make sure that there are no issues there.  If teeth need to be floated, that will likely be a separate appointment at the veterinarian’s clinic.

One last item – be sure to keep a check on your horse’s hooves.  We are experiencing a long period of mud, so be sure to check feet frequently.  Keep them cleaned out and make sure that no infections develop. Common things to check for are obsesses, thrush, fungus growing on the lower legs, heat in the hoof wall or sole, general lameness, or sensitivity.  If some work needs to be done on the feet, be sure to call the farrier sooner than later.  Before riding the trail or entering the ring at a horse show, be sure that the feet are good to go.

Parasite Control Options for Horses

A comprehensive parasite control program involves more than deworming your horse on a regular basis. The most important feature is the ability to reduce the number of parasites and eggs in the environment. Secondly, the program should be effective with the fewest number of treatments necessary. Finally, the program should be broad spectrum to control many different types of parasites.

Preventative medication is a very important component of parasite control. The bad news is that there is no single program that works for all situations. However, there are many different programs available, these include:

Targeted Dosing: This strategy involves testing the level of parasite burdens in individual animals. Standard fecal egg counts should be performed once monthly. Also tapeworm testing via fecal testing or serology (blood testing) should be done twice yearly. All animals that are positive over a certain cut off level should be treated. A yearly treatment for "bots" should also be included during the winter. This program is only appropriate for adult horses and should be considered on a farm with a dedicated manager where good grazing management is in place.

Strategic Dosing: This strategy involves treating all pastured animals at regular intervals with an appropriate product. The interval between dosing can be determined by the egg reappearance period (ERP)of the medication, which is shorter for young animals. The ERP is the period after medicating an animal with a dewormer until there are significant numbers of parasite eggs present again in the feces. The animals are only treated during the spring/summer season when the risk for increased egg loads is highest.

Interval Dosing: This strategy is the one most commonly used. It is similar to Strategic Dosing; however, animals are treated year round at regular intervals. As the duration of parasite kill varies from product to product and even between farms, the interval between doses should be determined by the ERP or by guidelines set by your veterinarian based upon products used. This program may be appropriate for farms where there are frequent new additions to the group, at more casually managed (hobby) farms and in young animals.

Daily Deworming: This strategy involves the addition of a parasite control medication to the horse's daily ration. This program is appropriate for most adult grazing horses; however, additional periodic deworming with other products is usually necessary. Twice yearly treatment with ivermectin (Eqvalan, Phoenectrin, Zimectrin), ivermectin/praziquantel (Equell) or moxidectin (Quest) has been recommended. This program can select somewhat for resistant organisms since the parasites are continuously exposed to a low level of the drug.

Click here for more information about deworming your horse.

Source: Jeremy D. Frederick, DVM, University of Minnesota

Do Fly Predators Fit In Your Fly Control Program?

Stable Flies and House Flies are two of the more common species of flies that bother horses during the warm months, especially around barns and stables.  Since it is April 1 (no fooling!), warmer temperatures are almost here, so it is time to consider what the fly control program will consist of during the rest or 2019.

Most horse owners and barn managers incorporate several fly control tools into the program to achieve the best results.  One method is mechanical control – removing manure, old bedding, and other fly breeding areas from the stable or barn.  Often this material can be composted, which will destroy any eggs and larvae during the process of turning this material into a pretty good soil amendment for gardens and landscapes.  Another is using insecticides to eliminate flies in concentrated areas, barriers are used to prevent flies from landing on the horse, especially around the face and eyes. Other tools include feed-through products for larvae control, and fly traps.

One tool that doesn’t get much discussion is the use of fly predators on horse farms.  These predators are tiny wasps that do not sting people or animals, but instead search for fly larvae to lay their eggs in. The predator larvae hatch inside the fly larvae and feed on it, preventing that fly larvae from becoming and adult fly. This helps to break up the fly life cycle and reduces the fly pressure around the horses.

There are several species of fly predators, and they are fairly specific to the type of fly they will help control.  They work best on either house flies or stable flies.  Some of the more commonly found species of fly predators and the type of flies they control are:

·     Spalangia nigroaenea - attacks both house and stable flies. 

·     Muscidifurax raptor– attacks house flies.

·     Muscidifurax zararaptor – attacks house flies.

·     Spalangia nigra – attacks stable flies.

·     Spalangia cameroni – attacks stable flies

·     Spalangia endius  - attacks stable flies

There are other species that will attack horn flies and face flies, but house and stable flies tend to be the ones found in stables and barns where the fly predators are more effective and cost efficient.

To use the fly predators in a fly control program, identify “hot spots” around the barn, and distribute the predators near those according to recommended populations of predators for the number of horses present.  The fly predators will travel up to 80 yards to find manure that contains fly larvae to parasitize. However, the fly predator population will not keep up with fly numbers throughout the fly season, so monthly releases of the fly predators through the control season are recommended.

Take care when using fly control insecticides if using the fly predators.  Don’t spray near the areas where fly predators have been released as the insecticide will also kill the fly predators.  If using a feed-through fly control product, the fly predators may be better used around concentrations of grass clippings, old bedding, or old round bales left on the ground. House and stable flies will lay eggs in these materials, so if they are not handled properly, these materials can be a breeding ground for flies.

There is no magic treatment that will totally eliminate the fly problem, which is why an integrated control program using different methods is recommended.  Sanitation, barriers, mechanical controls, insecticides, and biological controls can be combined to provide wide-spectrum fly control. Perhaps fly predators can be an effective tool to help in the fly control battles this summer.

New School of Thought on Parasite Management

         Often as the Small Ruminant and Equine Extension Agent I get calls regarding horses and parasites. In recent years the industry has begun to see a shift in the way we approach and handle internal parasites of many species, particularly horses.  In the past, parasite management in adult horses was largely based on knowledge that is now considered to be outdated. The purpose of this article is to discuss the new approach to parasite management in adult horses. It is important to note that these are merely researched based suggestions and it is still important for one to work closely with their veterinarian in developing a farm specific parasite program.

         In order to fully understand the scope of the parasite issue, horse owners must understand the parasites at hand, dewomers, and resistance. It is important to understand why these changes in parasite managment have occurred. Recent research has demonstrated the following:

1.    Switch in type of parasite focus. Large strongyles have for the most part been eradicated and new parasites of focus are small strongyles and tape worms. A recent survey performed in the Southeast United States, focusing on small strongyles, found that 95% of herds demonstrated a resistance to panacur, 53% of herds were resistant to Anthelcide ® and 40% of herds were resistant to Strongid ®. Horse owners should note that small stronglyes affect all grazing horses so focus should not be for complete eradication but rather to treat only when needed. Small stronglye parasites are low pathogenic, meaning they only produce a disease when parasite loads are high.

2.    Increase in anthelmintic (dewormer) resistance across the board, which is the ability of worms to survive treatment; this problem has occurred due to old school of thought where one should rotate type of dewormer every two months and the lack of accurate dosing resulting from not having a true weight of the horse.

3.    Adult (over age of 3) horses vary greatly in regards to needing to be dewormed due to immune response.

Dewormers can be grouped into 3 drug classifications: Benzimidazoles, Pyrimidines, and Macrocyclic Lactones. Knowing the drug classification of a dewormer can help owners to stop rotation of dewormers.  The table below denotes these classifications and common horse dewormers that fall into their category.

Drug Class	Common Dewormers
Benzimidazoles	Fenbendazole (Panacur ® ) and Oxybendazole
Pyrimidines	Pyrantel (Strongid ® )
Macrocyclic Lactones	Ivermectin and Moxidectin (Quest ® )

         There are many factors to consider when developing a parasite management protocol for your farm. When working with your veterinarian these are a few things horse owners should take into consideration:

1.    Ivermectin is a larvicidal (will kill larvae) and a boticide. If used every 6 months large strongyles will be eliminated from your farm. It is equally important when introducing a new horse on farm one should deworm them immediately, stall them for a minimum of 4 days to prevent worm contamination.

2.    Horses develop an immunity to roundworms.

3.    Eggs can last for years in the environment so preventing contamination is essential.

4.    Perform fecal egg counts. Fecal egg counts will provide one with the type of parasites and load of parasites. Knowing what worms and how many are present one can determine how to treat or even if treatment is necessary.

5.    Fecal egg count reduction tests can provide horse owners with information necessary to determine if a dewormer is still working on farm.

EPG = Egg Per Gram

                EPG Pre-treatment – EPG 14d post-treatment  x 100 = FECRT      

                           EPG pre-treatment

6.    Products containing praziquantel (Equimax ®) are effective against tapeworms. Tapeworms are carried by the pasture mite which dies after first hard frost. So, deworming with a product containing praziquantel is recommended yearly.

7.    Pasture management is a vital aspect of parasite management. Overpopulating and overgrazing pastures will inevitably lead to parasite transmission. Picking up manure piles in pastures instead of dragging them are now considered better options to reduce contamination.