A General Overview of Diarrhea in Foals (Part 1 of 3)
Articles Blog

A General Overview of Diarrhea in Foals (Part 1 of 3)

November 17, 2019


Diarrhea is the most common ailment to foals, with almost every foal experiencing diarrhea
at some point. However, as an owner, it can be very difficult
to determine if the diarrhea that your foal is experiencing is life-threatening, if you
should consult a veterinarian, and what treatment, if any, should be given. In this three-part series, I will review the
common non-infectious and infectious causes of diarrhea and the recommended steps that
should be taken when diarrhea occurs. There are many causes of non-infectious diarrhea
in foals, such as Foal Heat Diarrhea, Errors in Feeding, Antibiotic Induced Diarrhea, Parasites,
Lactose Intolerance, and Secondary Gastric Ulceration and Meconium Impaction. Foal heat diarrhea is the most common cause
of non-infectious diarrhea in foals. This is the diarrhea that occurs nearly in
all foals between seven and ten days of age. It’s called foal heat diarrhea, or scours,
because it coincides with the foal’s dam’s first heat cycle or estrous follow foaling. It was previously thought that hormonal changes
in the mare’s milk composition was the cause of this diarrhea; however, orphan foals or foals separated from the dam also experience diarrhea at this time. As veterinarians, we now believe that the
cause of this diarrhea is a change in the normal flora, or bacteria, that populate the
foal’s intestine and this causes a transient change in the digestive process, which results
in diarrhea. Other causes of non-infectious diarrhea, such
as errors in feeding, usually have a history to implicate them. This, for example, is seen in foals which
are bucket fed, such as orphans. Errors can occur in the concentration of the
milk replacer used or the frequency of feeding. Lactase is made by the cells in the tips of
the small intestinal mucosal brush border. Primary lactase deficiency is rare in foals,
but secondary deficiency, due to intestinal damage by infectious agents such as rotavirus
or Clostridium difficile is not uncommon. Although lactose intolerance can be confirmed
by testing, supplementation is inexpensive, practical and safe, and therefore testing
is rarely performed. It is important to remember that foals of
this age can also be affected with other more serious forms of diarrhea. Infectious causes of diarrhea usually result
in a whole body or systemic response to the infection and the foals are usually depressed
and quiet. In addition to this change in attitude there
are several other ways to tell the difference. Monitor the foal’s rectal temperature. A foal’s normal rectal temperature is between
99 and 101.5 degrees Fahrenheit. Monitor the foal to make ensure that he or
she is nursing adequately. A normal healthy foal will nurse several times
an hour and will run to nurse the mare on someone entering the stall. If the mare’s udder is full, dripping milk,
or if the foal has ‘milk staining’ of the forehead, it is likely that it is not nursing
adequately and that it is sick. Monitor the foal for diarrhea. Normal nursing foals have a yellowish, pasty
manure, which is totally normal. Foals with diarrhea have a more watery feces
which is variable in color and diarrhea may stay the hindquarters or can be seen dripping
from the tail. If you notice any of these signs in your foal,
you should contact your veterinarian immediately and separate the mare and foal from other
young stock until the likely cause of the diarrhea can be determined. Thank you for watching. In the second video of this series, I discuss
the various infectious agents that often lead to diarrhea in foals.

Leave a Reply

Your email address will not be published. Required fields are marked *