What you see. The starting point for addressing any equine health related issue is your observation.


Tail Hair Loss, Broken Hairs at Base


It takes about two years for a horse's tail hairs to grow full-length. The tail is vital for swatting flies. Thus, the loss of tail hair is undesirable for reasons beyond mere cosmetic appearance.

Broken hairs at the tail base usually indicate that a horse has been rubbing its tail head. This is commonly associated with insect irritation and hypersensitivity. Pinworm infestation also causes irritation to the skin around the anus. There may be increasing incidence of Pinworm infestation as resistance to parasite control compounds increased. Irritated, dirty sheaths can cause geldings to rub their tail heads.

Similarly, mares that have accumulations of material around the udder, or smegma accumulation in the clitoral fossa within the vulva can also engage in this behavior. Very rarely, the hair shafts spontaneously break from nutritional or toxic causes.

  • Code Yellow

    Contact Your Vet at Your Convenience for an Appointment

your role


What To Do

Inspect the mane carefully for evidence of similar hair loss there. Evaluate the facility for evidence of rubbing. Consider your parasite management program and whether insect irritation could be a contributing cause. Check the vulva and udder areas in mares. Assess the sheath in geldings. Share your findings and concerns with your vet.

your vet's role

Your vet can assess your overall management and the horse's general health, and help you manage many of the predisposing causes. Diagnostics may be run for parasites, including pinworms. In some cases, additional bloodwork and diagnostics may be necessary.
Questions Your Vet Might Ask:
  • Are flies bothering the horse?
  • What is the horse's age, sex, breed and history?
  • What is your parasite control program?
  • Do you notice many small skin bumps over the body (hives)?
  • Do you notice skin lesions elsewhere?
  • Are you seeing hair loss involving the mane?
  • What are the results of the Whole Horse Exam (WHE)?

Diagnoses Your Vet May Consider

The cause of the problem. These are conditions or ailments that are the cause of the observations you make.

Very Common
Less Common
more diagnoses

further reading & resources


Helpful Terms and Topics

Written, reviewed or shared by experts in equine health

Author: Doug Thal DVM Dipl. ABVP