Are Fall Booster Shots Right for Your Horse?

 We've had a few cool nights here in the Carolinas and it finally feels like fall has arrived!  You may be thinking longingly of the rides you'll have without dripping sweat.  Maybe you even have a few fall trips planned?  Calling your veterinarian to schedule vaccinations is probably at the bottom of your list...those shots are only due in the spring right?  

Despite the cooler temperatures, those pesky disease carrying mosquitos we all despise will linger sometimes as late as November.  Mosquitos are known to transmit WEE/EEE (Western/Eastern Equine Encephalitis) and WNV (West Nile Virus).  You probably vaccinated against these illnesses in the spring, but over time, vaccines can lose some of their efficacy, depending on the health & condition of your horse and their environment.  Your veterinarian can tell you if a booster is best for your horse.  

In addition to insect borne disease, there are a number of respiratory infections that plague horses in the fall and winter months.  Two common examples that can be vaccinated against are herpes virus complex (including rhinopneumonitis "rhino") and equine influenza.  Not every horse needs to be vaccinated against these infections, but horses at higher risk for exposure may benefit from a dose of added protection.  Horses you plan to show or travel with this fall or horses stabled at a barn with lots of horses coming and going from other places are considered at higher risk.  Your veterinarian will be able to tell you if your horse falls into this category.  

The American Association of Equine Practitioners (AAEP) has recommendations for vaccine schedules for horses in various levels of work. Having a relationship with a local veterinarian that can help you create a vaccine schedule that fits your horse is the key to successful prevention of disease.  

If your horse is a candidate, talk with your veterinarian and consider fall vaccinations.  You don't want to miss a minute of the best rides of the season!

Parasites: An Ounce of Prevention is Worth a Pound of Cure

Many of us are familiar with the previous standard for deworming horses - a rotational system where a different class of dewormer is administered every 8 weeks like clockwork to all horses on the property. The problem with that, we now know, is that it increases parasite resistance, which in turn decreases the efficacy of those dewormers in the future. Let’s break down how this can happen: 

1. Dewormers are administered and susceptible parasites are successfully destroyed. 

2. The less susceptible (stronger) parasites are left behind, but have now encountered the dewormer and have the opportunity to form resistance to it.

3. Those less susceptible, now more resistant parasites continue to exist in the internal and external environments, and continue to multiply.

4. The same dewormer is administered again, but the parasites are now resistant and unaffected by it.

According to a recent article from PennState Extension**, “small strongyles have widespread resistance to benzimidazoles, moderate resistance to pyrimidines, and early indications of resistance to macrocyclic lactones. Ascarids have widespread resistance to macrocyclic lactones and early indications of resistance to both benzimidazoles and pyrimidines.” The article goes on to say that horses tend to develop immunity to ascarids (roundworms) while young, so small strongyles become the main parasite we worry about becoming resistant in our mature adult horses.

Table 1: Taken from University of Minnesota Extension

Fortunately, horse owners have several tools in their toolbox to reduce and prevent this resistance from building up on their farms in the first place. The proverbial “ounce of prevention” can include: 

1. Manure Management - You’ve probably noticed your horses avoiding grazing in certain areas in the pasture, specifically where they have pooped. This is a natural instinct to avoid parasites. When complete removal of manure from an area for composting is not practical, like a pasture for example, we tend to look towards harrowing or dragging to break up manure and spread it around. This can be beneficial in a dry, hot climate where temperatures have been high and rainfall low consistently for several weeks. This is more helpful for strongyles than roundworms, which can withstand the hot and dry conditions. However, in a moderately warm and moist environment, spreading the manure can be more harmful than helpful altogether. This can take away the horses’ ability to graze around the infected feces. The best case scenario is to be able to keep horses off of a pasture for several hot and dry weeks after harrowing or dragging.

2. Rotational Grazing - Moving horses from one pasture to another in general can be extremely beneficial for the horses as well as the pastures. A period of rest gives the grass time to recover and strengthen its root system before being grazed again, making it heartier overall. What you see on top of the ground in a pasture is typically reflective of what the root system beneath it looks like. Parasites also like to live in the bottom 2-4 inches of the grass, so being able to pull horses off of a pasture when they get down to about 4 inches can greatly reduce their exposure to parasites in the first place. The less parasites they ingest, the less there will be for you to have to get rid of. Stocking density comes into play here as well. It is important to make sure there is enough grass relative to the amount of horses it is expected to support.

3. Fecal Egg Counts (FECs) - These tests are a great way to estimate the current parasite load of your horse at a given time. It is important to ensure that the sample being tested is fresh, uncontaminated, and handled correctly. This test can help evaluate how effective a dewormer was when administered. It is important to note that this test is not perfect. It does not reflect adult worm load or larva, and has been known to miss tapeworm and pinworm infections as well. The main parasite a fecal egg count detects is strongyle eggs. Therefore, it is still recommended to deworm adult horses at least one to two times each year for the parasites that may not have been detected on tests, like tapeworms, pinworms, bots, etc. Fortunately, anthelmintic resistance has not been reported in these parasites as strongly as it has with small strongyles.

4. Knowledge - Understanding the life cycle of different parasites can be extremely beneficial to horse owners when they go to plan their parasite management strategies. Timing treatments and preventative methods to coincide with stages of the life cycle is important. You want to make sure you are conducting FECs, administering dewormer, spreading manure, and rotating pastures, all at the right time to minimize parasite burden. 

Finally, it's important to remember that just like with most other things, horses can vary significantly from one to the next when it comes to factors that influence deworming needs. Things like age, shedding rates, and natural immunity can be so different between individuals that it is virtually impossible to develop an effective one-size-fits-all plan for a farm. Make sure to involve your veterinarian in developing a plan for each individual horse. You can also contact your local extension office for further resources to help with pasture management, conducting fecal egg counts, and much more.

**https://extension.psu.edu/decoding-dewormers-types-resistance-concerns-and-use-for-horses

Common Types of Colic

 Colic is a word that terrifies horse owners. Colic is caused by many factors, including things we usually can’t control, such as a sudden weather change. Luckily, colic doesn’t always have to result in expensive surgery or euthanasia. There are multiple types of colic, and most can be treated if caught early. The four main types of colic that occur in our area are gas, impaction, sand, and twisted gut.

Gas colic is the most common, has the most straightforward treatment, and is usually not fatal. Gas colic can be caused by sudden changes in feed, ulcers, dehydration, stress, and insufficient forage intake. Horses may appear extremely painful, but this usually resolves with pain medication, fluids, and walking. This type of colic can be prevented by feed and environmental management. 

Impaction colic can be caused by feeding lower quality or stemmy feed materials, ingesting foreign materials such as seeds, and improperly chewed food.  This is common in horses who are older or need their teeth floated. Impaction colic can sometimes be treated by a veterinarian administering fluids, mineral oil, and anti-inflammatories. Impaction colic can be fatal if not treated quickly.  Owners can prevent an impaction by feeding appropriate forage for their horse, dental maintenance, and ensuring their horse drinks adequate water. 

Sand colic is common in horses that live in sandy areas, like the Sandhills and Coastal Plains of North Carolina, and who eat their hay off the ground. The sand irritates the intestinal lining causing pain and disruption of digestion. If not treated promptly, the loose sand in the intestines can harden and form stones, which are painful and may cause an impaction. This can be prevented by feeding out of a hay net or raised bale feeder, and giving supplements like Sandclear and Sandpurge.

The final common type of colic is the twisted gut, which occurs when some part of the intestine twists around itself and is almost always fatal.  The twist can sometimes be corrected by surgery if caught early, but often the tissue in the intestines begins dying before surgery can be performed. Preventing the other mild types of colic can help prevent a twisted gut. 

It is important to know the signs of colic so treatment can be started as soon as possible. Talk to your veterinarian to develop a plan so you can be prepared if your horse does colic. 

Signs of colic:

• Kicking at their stomach

• Flank watching

• Pawing the ground/acting anxious

• Bloating

• Excessive sweating

• Rolling

• Not eating or drinking

• Stretching 

• Not passing manure

• Tacky gums

• Heart rate over 50 beats per minute

• Lack of gut sounds using a stethoscope

If you suspect that your horse is experiencing colic:

• Begin walking your horse

• Call your veterinarian to inform them your horse is colicing

• Administer an oral anti-inflammatory medication as advised by your veterinarian

• Remove feed

• Keep horses in an open area to prevent getting caught on something if they roll.

• Ask your veterinarian to come to your farm if

• There is no improvement from walking and anti-inflammatories 

• You do not know how long the colic has been occurring or has occurred for several hours.

• Vital signs are abnormal.

• Gums appear dark red or purple

• If any of the above signs occur for longer than 30 mins.