PINWORMS – literally a pain in the butt!

Any horse owner who has watched their horse rub it’s backside raw will tell you how frustrating it can be to treat pinworms.

The reason for this is largely to do with the life cycle of pinworms. 

  1. The life cycle is long (approx 5mths), compared to most other worms which have a life cycle of approximately 3 weeks. Immature stages of the worm are less sensitive to dewormers so may survive post-treatment. 
  2. Adult pinworms live in the rectum, whilst other worms live in colon or intestine. 
  3. Adult females exit the rectum and lay eggs around the anus of your horse. The females then pass out of the anus and die.

REMEMBER – Pinworms do not show up on a fecal egg count as the adult worms lay the eggs externally!


Signs : 

  • Tail rubbing 
  • Hair loss loss over the base of the tail 
  • Red/inflamed skin 
  • Irritability & restlessness

Treatment : 

Management of pinworms is labour intensive and lasts several weeks to months. Successful treatment is two-fold and involves correct use of dewormer and strict hygiene practices to reduce contamination and re-infection.

  1. Due to overuse of certain wormers, some compounds are no longer effective at killing pinworms. We recommend a combination of fenbendazole / pyrantel (eg. Strategy T). The number of treatments is determined by each individual case. Contact us for more information regarding your horse.
  2. Disinfect any area your horse has come into contact with (stable doors, gates, feed bins, fences). 
  3. Wash all rugs thoroughly 
  4. Pick up manure 1-2 times a day
  5. Wash your horses perianal area daily with dilute betadine solution. Adult female worms are most active overnight so this is best done first thing in the morning. 
  6. Wipe your horses perianal, tail and dock area several times a day to remove any eggs. We recommend disposable wipes so you can easily throw these out. Do not re-use sponges. 
  7. There is some anecdotal evidence that application of vaseline around the perianal area might be helpful.

Remember, it is also important to rule out other causes of tail rubbing such as allergies or dermatitis. Please contact us on 0427 072 095 if you would like more information.