Worming your horse is a vital part of maintaining their health, as internal parasites (worms) can negatively impact their condition, performance, and overall well-being.
However, it’s not always easy to know when your horse needs worming. Horses may not always show obvious signs of worm infestations, but there are certain symptoms to watch for that can indicate the need for treatment. Here’s how you can tell if your horse needs worming and the signs you should look for.
1. Change in Coat Condition
A dull, rough, or patchy coat can be a sign that your horse may have an internal parasite problem. Worms can affect a horse’s overall health, and one of the visible signs is a coat that looks unhealthy or less shiny. If your horse’s coat loses its shine, becomes dry, or looks scruffy despite good nutrition and care, worms could be the culprit.
What to Look For:
- Dull, lifeless coat
- Hair loss or patches of hair thinning
- Flaky or dry skin
2. Poor Weight Gain or Weight Loss
Worms compete with your horse for nutrients, which can cause weight loss or prevent your horse from gaining weight even with a good diet. In foals and young horses, a worm burden can stunt growth. If your horse seems to be eating normally but is either losing weight or struggling to gain weight, internal parasites could be to blame.
What to Look For:
- Weight loss or inability to gain weight
- Muscle wasting or a sunken appearance
- Pot-bellied appearance (particularly common with roundworms)
3. Dull or Decreased Energy Levels
If your horse seems lethargic, weak, or just lacks its usual energy and enthusiasm, worms could be affecting its overall vitality. Parasites can deprive your horse of essential nutrients, which can lead to reduced stamina and fatigue. Horses that are normally lively may seem sluggish and uninterested in work or play when they have a worm burden.
What to Look For:
- Lethargy or sluggish behavior
- Decreased interest in exercise or daily activities
- A lack of enthusiasm or energy during riding or turnout
4. Changes in Appetite
Some horses may show changes in appetite if they have worms. This can vary from a sudden increase in appetite (trying to compensate for nutrient loss) to a noticeable decrease in interest in food. In some cases, horses may start to eat unusual objects (pica) to try to get more nutrients.
What to Look For:
- Increased or decreased appetite
- Eating unusual objects like dirt or bedding (pica)
- Difficulty in maintaining or gaining body condition despite eating normally
5. Diarrhea or Loose Manure
While diarrhea can be caused by various factors (like diet or stress), it can also be a symptom of a heavy worm infestation. Some types of worms, particularly strongyles or tapeworms, can irritate the horse’s digestive system, leading to loose stools or diarrhea. Horses with parasites might have a change in the consistency of their manure, or they may experience frequent, watery stools.
What to Look For:
- Diarrhea or loose manure, especially if it’s not related to diet or stress
- Soft or mushy manure
- Frequent droppings or change in bowel movement consistency
6. Colic or Abdominal Pain
Worms can sometimes cause colic or digestive upset, especially if there is a high worm burden. The physical presence of worms can irritate the intestines, leading to cramping or discomfort. Some types of parasites, such as large strongyles, can cause significant damage to the horse’s gut, resulting in abdominal pain or colic symptoms.
What to Look For:
- Signs of colic (pawing, rolling, looking at the flank)
- Abdominal discomfort or bloating
- Loss of appetite due to pain
7. Visible Worms in Manure
While it’s not always easy to detect internal parasites just by looking at your horse, one obvious sign that your horse needs worming is if you notice visible worms in its manure. Some worms, such as tapeworms and strongyles, may appear in the droppings, especially after treatment. If you observe these types of worms, it’s time to schedule worming.
What to Look For:
- Small, white, rice-like segments in the manure (tapeworms)
- Long, thin, spaghetti-like worms (roundworms)
- Worms or egg masses in the manure
8. Itching or Tail Rubbing
If your horse is constantly rubbing its tail or hindquarters, this may be due to pinworms, a common intestinal parasite. Pinworms cause irritation in the rectal area, which leads to tail rubbing or scooting. This type of parasite is more common in young horses, but adult horses can also get them.
What to Look For:
- Frequent tail rubbing or scooting behavior
- Irritation around the tail or hindquarters
- Scratching or biting at the hind end more than usual
9. Unusual Behavior or Increased Irritability
Horses with heavy worm infestations can sometimes exhibit behavioral changes, such as irritability, nervousness, or discomfort. This can be due to the physical discomfort caused by worms, or it can stem from a lack of proper nutrients, which may make the horse more sensitive or less tolerant of normal activities.
What to Look For:
- Increased nervousness or irritability
- Unexplained mood swings or behavioral changes
- Signs of discomfort when being ridden or groomed
10. Foals and Young Horses Are at Higher Risk
Young horses, such as foals and weanlings, are particularly vulnerable to worms. Because their immune systems are still developing, they’re more susceptible to parasitic infections. In foals, common signs of worm infestations include poor growth, a pot-bellied appearance, and failure to thrive.
What to Look For in Foals:
- Pot-bellied or bloated appearance
- Poor growth or failure to thrive
- Reduced activity levels or lethargy
How to Prevent and Treat Worm Infestations
- Fecal Egg Counts (FEC): The most accurate way to determine if your horse has a worm infestation is to perform a fecal egg count. This test analyzes your horse’s manure for eggs and larvae, helping to assess the type and number of parasites present.
- Regular Deworming Schedule: Follow your vet’s advice on a deworming schedule. This may involve rotating different types of wormers to avoid resistance and target a broad range of parasites.
- Pasture Management: Keep your horse’s environment clean by picking up manure regularly and rotating pastures to limit exposure to worm larvae. Consider grazing management and limiting exposure to areas that are heavily contaminated.
Final Thoughts
While some horses may show clear signs of worm infestations, others may not display symptoms until the infestation becomes severe. Regular deworming, fecal egg count testing, and attention to signs of worms are essential in keeping your horse healthy. If you notice any of the signs mentioned above, it’s important to consult your veterinarian, who can recommend the best course of action for deworming and parasite control.