The Scoop On Fecal Egg Counts

QUESTION: 

I have read a lot on Fecal Egg Counts over the past few months.  Could you discuss the appropriate use of counts here in Colorado?

 

ANSWER:

In the last Ask a Vet, we discussed rotational deworming and its application here in Colorado.  Fecal Egg Counts (FEC’s) are a tool that we use to help us direct rotational deworming.  A FEC is a test the counts the actual number of parasite eggs within the horses’ manure.  This is done by submitting a small sample of manure to your veterinarian.  Your veterinarian then runs a floatation test on the sample and counts the number of parasite eggs that are present in that sample, reported as eggs per gram of feces.  The ideal time to run the test is about 3 months after the last dose of dewormer was given, which allows an appropriate timeframe for parasite eggs to reappear.  This gives you the baseline amount of parasites that your horse has present without interference from any deworming drugs.

 

At this point, each horse within a herd can be ranked in regards to the amount of parasite eggs that they are shedding.  This ranking is dependent upon each horse’s individual natural immunity to internal parasites.  The extended timeframe since the last deworming gives us insight into the immune system of the horse and its ability to naturally fight off parasites, rather than the efficacy of the last dewormer used. 

 

We will generalize and place each horse into a broad category of parasite shedding.  If, a horse is found to be a “low” shedder, then it is possible that the horse can be dewormed less frequently (once every 6 months).  These horses have a higher natural immunity to parasites, and are less likely to accumulate a large number of parasites within their system.  Many horses fall in the “moderate” shedder category.  Normal deworming for these horses would be considered quarterly rotational deworming (previously discussed here), where the horse is dewormed about every 3 months.  The “high” shedders are the problem horses.  These are often older or immune compromised horses, which are unable to fight of parasites.  These horses should be dewormed more frequently (up to 5 or 6 times a year). 

 

The second part of the Fecal Egg Count is the egg reduction test.  After the “baseline” is established, a second test sample is taken 10 to 14 days after deworming.  This sample allows us to determine if there is a drug resistance problem within your herd.  If the dewormer that you gave is effective, then a horse should have a significant (>90%) reduction in the number of eggs seen within the manure.  If there is less than 90% reduction in the number of eggs, then the dewormer that you used lacks efficacy or you have resistant parasites to that dewormer present in your horse.  In combination with appropriate rotational deworming, Fecal Egg Counts can help guide parasite control for your horse, and potentially save you some money on deworming products.  More importantly, FEC testing can help you to more closely monitor you horses’ health, and potentially help save you money in the long run.

Rotational Deworming… What’s the Right Choice?

QUESTION: 

Can you please discuss “appropriate” rotational deworming?

Due to the influx of deworming questions, we will tackle them in 2- 3 parts over the next few months.

 

ANSWER:   

Standing in the feed store, there are dozens of packages of dewormers, and the age old question of, “which one do I use now?” goes through every horse owners mind.  The answer to this question is not always a simple one.  To appropriately deworm your horse through the year, a rotational deworming program is essential. 

            Here in Colorado, we usually recommend quarterly rotational deworming.  Some herds may require more frequent or less frequent deworming, depending on fecal egg counts. (To be discussed here at a later date). 

Rotational deworming is exactly what it sounds like, rotating through different chemical classes of drugs throughout a year’s timeframe.  Though the name brand might be different, the active ingredient is the important part to rotate.  The idea behind rotating the chemical classes is to reduce the chance of a parasite developing resistance to a type of drug (much like antibiotic resistance).

            To begin rotational deworming this fall on an adult horse our recommendation is using an avermectin product.  There are dozens of avermectin products on each shelf, with various name brands (to name a few – Equell, Equimectrin, Ivercare, Rotectin, Zimectrin, and Horse Health Ivermectin and Quest Gel).  Avermectins have a very broad base of activity, but there are a few types of worms that are not killed.

            In the winter quarter, we usually recommend, for an adult horse a benzimidazole product.  When you’re at the counter, the easy way to remember is that you are looking for an active ingredient that ends with “azole.”  A few name brands in this class are Safe-Guard, Panacur, and Anthelcide EQ. 

            In the spring quarter (usually about the time you see us for spring shots), we rotate back to an avermectin product, but usually include praziquantel.  The praziquantel is effective against tapeworms.  The name brands in this class are Equimax, Zimectrin Gold, and Quest Plus.

            To come full circle and cover a full year, in the summer MVS likes to use a pyrantel salt based dewormer.  Some name brands in that class are Strongid Paste, Rotectin P, Pyrantel Pamoate paste and Liqui- Care P.

As another alternative to quarterly deworming, there is the option of daily deworming (feeding a small amount of dewormer every day).  Using one of these products, you still need to “rotate” and 2 times a year give a paste dewormer.  Our recommendations for these horses on daily dewormers are to use an avermectin once a year, and then a benzimidazole about 6 months later. 

            With appropriate rotation of deworming products, your horse should maintain a minimal parasite load. 

            Look for the next post regarding Fecal Egg Counts to round out your deworming knowledge.

 

 

In Summary:

MVS Rotational Deworming Recommendations (Quarterly Deworming Schedule):

 

–         Fall:  Avermectin (Ivermectin or Moxidectin)

–         Winter:  Benzimidazoles (Fenbendazole or Oxibendazole)

–         Sping: Praziquantel w/ Avermectin

–         Summer:  Pyrantel Pamoate

 

Horse Rabies In Colorado

rabies_shotQUESTION:
I have heard on the news over the last week or so about a couple of cases of Rabies in horses here in Colorado. Should we be vaccinating the horses for Rabies?

ANSWER:
The short answer is yes, here at MVS, we are currently recommending rabies vaccines for all of our equine patients.
There are many different “variants” of rabies, but here in Colorado we are concerned about only two. Bat rabies is carried in insectivorous bats (they eat only insects) here in Colorado and there is a low incidence of exposure and therefore transmission of the disease. Skunk (or terrestrial) rabies is carried by skunks and has a higher chance of exposing domestic pets and horses. Here in Colorado we have always had an incidence of bat rabies (though never reported in horses before 2009). Since 2008 there have been an increasing number of cases of skunk rabies reported. This has also led to a small increase in the number of domestic animals that have been exposed and tested positive for rabies, including a small number of horses. Since 2009, El Paso, Adams, and Douglas counties have each reported a case of rabies in a horse.

For a small cost each year, a horse can be protected from this 100% fatal disease. The vaccine is effective at protecting the horses, and is also quite safe. For a disease like rabies, where there are very serious public health ramifications to you and your family, the rabies vaccine is a great idea. Although the risk of exposure is still small, a properly vaccinated horse is the only horse that will survive infection with rabies.

As a note, we spoke with the state veterinarian today, and they confirmed that a horse has to be vaccinated by a licensed veterinarian to be considered protected from the disease. Therefore, in the event of a suspected rabies exposure, if your horse was not vaccinated by a veterinarian, they will be considered unvaccinated by the State of Colorado!

Why do I need to float my horse’s teeth?

floating_teethQUESTION:
Over the past couple of months, I have been having some trouble with my 5 year old gelding tossing his head while I am riding. He takes the bit normally, and then shortly after we begin working, he starts throwing his head around, and gets quite agitated. We can usually work through it, but it is troublesome. I don’t remember him doing anything like this last summer, could there be a medical issue?

ANSWER:
There are a number of possible reasons for the head tossing. The most common reason that we find here at MVS for head tossing, is dental issues.
One of the most important lines of communication with our horses can be through the mouth. Halters, bridles and bits are all a means of communicating our intentions when riding and also when leading our horses. An often overlooked reason for this line of communication to break down can be due to problems with the horse’s mouth.
Dental work in horses has progressed quite a bit in the past 10 years. Gone are the days of simply running a float up in a horse’s mouth with no sedation or restraint. To perform a full dental exam, we will most likely want to sedate your horse and use a full mouth speculum. This allows us to examine the entire mouth, all the way to the teeth in the very back of the mouth. Routine exams of the mouth usually find sharp points on the outside surfaces of the upper teeth, next to the cheeks. These sharp points can cause painful oral ulcers, which can be exacerbated when bridles/headstalls place pressure over the area of the ulcer with their cheek bands. A common complaint from a horse that is in need of dental work is that the horse has been “throwing his head” or “fighting the bit”. This is a result of these painful oral ulcers being aggravated with the bridle. We will be able to assess this type of problem with a full mouth speculum exam.
A good time to think of getting your horse’s first dental exam is around the time that your horse begins training/riding lessons. This corresponds with the first time that we ask our horses’ to take a bit as well. A common misconception is that only older horses need dentistry performed. Young horses actually get much more out of routine dentistry than their older counterparts. Young horse teeth are softer than older horse teeth and as a result can change more quickly than old horse teeth. This means that the edges of your young horse’s teeth can develop points on them that are as sharp as puppy teeth! Imagine trying to learn about a bit and bridle with those needle sharp points digging into your cheek or tongue. With a complaint of training difficulties in a young horse, one of the first things to is his mouth.

Horses that receive dental work on a regular basis are able to avoid some of these uncomfortable conditions. Regular dental work will also give us the opportunity to detect other abnormalities in the mouth as well. Malocclusions, or disruptions to the normal chewing surface of the tooth, can lead to fractures, tooth root infections, and a decrease in feed efficiency. Timely diagnosis and treatment of these problems will help to keep your horse healthy and making the most of his feed for years to come. We recently were able to work on a horse that just celebrated his 30th birthday. Since he has had regular dental work done for over 20 years, he still has a VERY healthy set of teeth left with which to chew. In contrast, I have seen 30 year old horses without regular dental care have very few healthy teeth left with which to chew hay. This can lead to weight loss, and a host of other health problems.

Communication with our equine friends is always an important aspect of enjoying our time riding. Doing everything that we can to eliminate distractions to the horse will only ensure that we have the most open lines of communication, leading to the optimum performance from our trusted mounts. When your horse clearly understands what it is that you are asking him to do, then he is much more likely to respond well to your request. With proper dental care, you can make the most of this season riding, and communicating, with your horse.