Spring into Action: Essential Tips for Equine Deworming

Equine deworming is a crucial aspect of horse care, but outdated practices have led to widespread drug resistance. This blog provides a comprehensive guide to modern deworming strategies, emphasizing targeted treatments based on fecal egg counts (FECs), strategic dewormer selection, and supportive care for your horse.

Spring is a time of renewal, growth, and, for horse owners, a chance to prioritize their equine partners' health. One essential aspect of spring horse care is deworming. Parasites, such as strongyles and ascarids, can pose significant health risks to horses if left unchecked. A proactive and strategic deworming plan is key to keeping your horses happy, healthy, and parasite-free. Modern deworming focuses on targeted treatments based on fecal egg counts (FECs) to minimize drug resistance, a growing concern in equine health. Here are some general tips to guide your springtime deworming routine. It's crucial to consult a veterinarian to develop a personalized deworming plan based on FECs and individual horse needs.

Parasite control is a cornerstone of equine health, yet it can often feel overwhelming with so many products, schedules, and strategies to consider. Understanding the basics of deworming can help horse owners make informed decisions to keep their equine partners healthy and happy. Let’s break down the essentials of deworming and how to develop an effective parasite control plan.

Understanding how parasites thrive and impact horses is essential for effective control. Environmental factors play a significant role; for instance, warm, humid climates promote strongyle larvae development, while bot flies are more active during specific seasons. Knowing what you're up against is the first step. Here are some common equine parasites:

Strongyles (Large and Small):

• Small strongyles are the most common and can encyst in the gut lining, making them harder to target.
  • It's important to understand the complexity of detecting encysted small strongyles. These larvae have the ability to burrow into the lining of the horse's large intestine, where they become "encysted." While encysted, they are in a dormant state, and they do not produce eggs that are passed in the manure. Therefore, a standard fecal egg count (FEC) will not detect encysted small strongyles. This burrowing and encystment make it very difficult to determine the burden of small strongyle larvae in a horse. The fact that they are not shedding eggs while encysted means that they are essentially "hidden" from traditional diagnostic methods. Moxidectin is particularly effective against encysted small strongyle larvae, but should be used strategically due to resistance concerns.
• Large strongyles are less common but more damaging, as they can cause significant blood vessel damage.

Ascarids (Roundworms):

• Primarily affect young horses, causing growth delays and intestinal blockages. Ascarid resistance to common dewormers is a growing concern.

Tapeworms:

• Often go undetected but can cause colic by affecting the junction between the small intestine and cecum.
• While FECs don't detect tapeworms, alternative diagnostic methods, such as saliva testing, are available. These tests offer a way to assess tapeworm exposure and inform targeted deworming strategies.

Bots:

• These are larvae of bot flies that attach to the stomach lining and cause irritation.

Pinworms:

• Pinworms are also a common parasite that can cause tail itching. They are diagnosed with the tape test.

For many years, the common practice was to routinely rotate dewormers every 8-12 weeks, regardless of a horse’s actual parasite burden. While well-intentioned, this practice has led to widespread drug resistance among parasites. Over-deworming unnecessarily exposes parasites to treatments, allowing resistant strains to thrive and spread.

To address this issue, the modern approach emphasizes targeted deworming based on need rather than a fixed schedule.

Fecal Egg Count (FEC) tests can be a valuable tool in parasite control. They measure the number of parasite eggs in a sample of manure, helping you determine whether your horse needs deworming and which parasites are present. Using FECs allows for targeted deworming, a method that combats the increasing problem of drug resistance. Here’s how they work:

• Baseline Monitoring: Conduct FEC tests regularly throughout the year to monitor parasite levels.
• Targeting High Shedders: Horses vary in their susceptibility to parasites. Roughly 20% of horses in a herd shed 80% of the parasite eggs. Identifying and targeting these high shedders helps reduce overall pasture contamination.
• Post-Treatment Checks: Conduct FEC tests 10-14 days after deworming to ensure the treatment was effective.

Keep in mind that FEC tests are most accurate when conducted during times when horses are actively shedding parasite eggs.

Choosing the right dewormer is crucial and should be guided by fecal egg count (FEC) results, targeted parasites, and veterinary recommendations. Here are the main classes:

Macrocyclic Lactones (Ivermectin, Moxidectin):

• Primarily for strongyles and bots.
• Moxidectin targets encysted small strongyles.
• Use strategically due to resistance concerns. However, due to resistance concerns, these medications should only be used when needed, based on FEC results.

Benzimidazoles (Fenbendazole, Oxibendazole):

• Effective against ascarids and some strongyles.
• Fenbendazole is available in various forms, including the "5-Day PowerPak" which involves a five-day consecutive treatment. This treatment was historically used to target encysted small strongyles and is the only product approved to act as a larvicidal treatment for stubborn EL3 (early stage) and L4 small strongyles. Fenbendazole is known for its relatively high safety margin, making it suitable for foals, senior horses, and debilitated animals. However, due to widespread resistance, its effectiveness against encysted larvae is now highly variable. Moxidectin is now often preferred for encysted strongyles.
• Use judiciously due to resistance. It is very important to consult your veterinarian, and perform a fecal egg count reduction test to determine if a benzimidazole product will be effective on your farm.

Pyrantel:

• Targets strongyles.
• Double dose can be used for tapeworms, but praziquantel is superior.
• Resistance is widespread.

Praziquantel:

• Specifically for tapeworms.
• Recommended over pyrantel for tapeworm control.
  Praziquantel is most frequently combined with:
  • Ivermectin: This combination provides coverage against tapeworms, strongyles, bots, and other internal parasites. This is a very common combination.
  • Moxidectin: Similar to ivermectin, moxidectin combined with praziquantel offers broad-spectrum control, including encysted small strongyles. This is another very common combination.
• Use when needed, or when a saliva test shows a need.

Specific Parasite Considerations:

Ascarids (Roundworms):

• Ascarid resistance to ivermectin, moxidectin, pyrantel, and benzimidazoles is a growing concern.
• Benzimidazoles (fenbendazole, oxibendazole) and pyrantel salts are currently the most effective treatments.
• Fenbendazole may be used against migrating larvae.

Pinworms:

• Pinworms have developed resistance to ivermectin.
• Benzimidazoles are currently the preferred treatment.
• Cleaning the area around the tail base can help relieve clinical signs. The tape test is the most effective diagnosis.

Bots:

• Bots can be treated with ivermectin or moxidectin in the late fall or early winter.
• Moxidectin's effectiveness can vary depending on the bot larvae's life stage.
• It is important to note that a boticide is not a specific medication, but instead refers to a medication that treats bots.

Deworming alone isn’t enough to control parasites. Good pasture management practices can significantly reduce your horse’s exposure to parasite larvae. Clean paddocks and pastures at least twice a week to reduce egg contamination. Rotate pastures to give grass time to recover and reduce parasite loads.

Supporting Your Horse During Deworming:

• Monitor for Signs of Discomfort: Keep an eye out for any signs of colic, diarrhea, or decreased appetite. Contact your veterinarian if you observe any concerning symptoms.
• Proactive Gut Support Tip: To further support your horse during parasite die-off, consider supplementing with ingredients like:
  
  • Slippery Elm Bark: To soothe and protect the gut lining.
  • L-Glutamine: To aid in gut repair.
  • Probiotics (e.g., Saccharomyces boulardii, Lactobacillus strains): To restore gut balance.
  • Inulin: A prebiotic to feed beneficial gut bacteria.
  • Aloe Vera: To reduce gut inflammation.

These ingredients can help alleviate discomfort and promote gut health during this time. Always consult your veterinarian before adding new supplements to your horse.

Every horse is unique, and a one-size-fits-all approach doesn’t work for deworming. Collaborating with your veterinarian ensures a personalized and effective parasite control plan. Your vet can assist with conducting and interpreting FEC tests. They can recommend the appropriate dewormer for your horse’s needs and also provide guidance on managing specific parasites in your area.

Understanding deworming is the key to effective parasite control. By learning about parasites, using fecal egg counts, selecting the right dewormer, and practicing good pasture management, you can safeguard your horse’s health and reduce the risk of drug resistance. Remember, a proactive and informed approach is always better than a reactive one.

DISCLAIMER: The information provided in this blog is for educational and informational purposes only and is not intended as a substitute for professional veterinary advice, diagnosis, or treatment. While ScoopRX strives to provide accurate and up-to-date information, we are not veterinarians, and the content herein should not be considered veterinary guidance. Always consult with a licensed veterinarian before making decisions regarding your horse’s health, including deworming protocols, supplement use, and parasite management strategies. ScoopRX is not responsible for any outcomes resulting from the use or misuse of the information provided in this blog.