A620
Parasites

 

Clinical Signs: Signs of infection are most common in young, very old or diseased animals. Most parasite infections cause weight loss, unthriftiness and poor weight gains. Some parasites can cause diarrhea, decreased appetite, and colic. If the parasites are migrating through the lungs, there may be coughing and nasal discharge. If the infection is extremely severe, death may occur.

Disease Transmission: Each one of the internal parasites is spread by orally ingesting the parasite in its infective stage. This most commonly occurs during grazing. The external parasites are spread by direct contact or having infested animals in close association with other animals.

Diagnosis:
  1. Internal Parasites - Most of these infections can be detected using a fecal egg count. This is done by collecting a fecal sample and sending it in to the local veterinarian for a fecal flotation. See page D220 for more specifics. These infections can also be diagnosed at necropsy.
  2. External Parasites - Actual parasites or any signs associated with general infestations can be observed during a routine examination of the animal.

Treatment/Prevention: Differences in treatment are based on the common parasites encountered and the geographical location in which a particular horse resides. It is recommended that a local veterinarian be consulted for specifics on timing and frequency of treatments. The following are a few of the available products:

For Internal Parasites:

Product Trade Name   

Active Ingredient   

**Effective Against

Eqvalan, Ivercare   

Ivermectin   

#1-3, 5, 7-9, 13

Quest   

Moxidectin   

#1-9, 13

Strongid   

Pyrantel   

#1-3, 5, 7-12

Dyrex   

Piperazine   

# *1, 5, *8, 9

Anthelcide   

Oxybendazole   

#1-3, 5, 7-9

Panacur   

Fenbendazole   

#1-3, 5, 7-9 

*   This product is effective against S. vulgaris and Oxyuris only 40-60% of the time.
** These numbers correspond with the numbers found above. For suggestions on a 
    specific deworming schedule see page A622.

Additional Management Ideas:
  1. Whatever deworming schedule is chosen, it is essential to rotate the use of each product to help minimize resistance build-up on the farm. When a particular product is used over and over again, parasites can become resistant to that de-wormer.
  2. Keep stalls and paddocks manure free.
  3. Do not spread manure on pastures.
  4. Keep feeders and water buckets manure free.
  5. Rotate pastures frequently and do not over graze.

External Parasites: There are many different sprays and pour-ons that are effective against most external parasites. It is important to remember to read the product label to ensure that each specific product can be given to horses. Pay close attention to dosage and administration instructions.