EQUINE | NHRA Excerpts
NHA LABORATORY WARNING ON
HORSERACING PROHIBITED SUBSTANCES
WHICH ARE CONTAINED IN READILY AVAILABLE
PREPARATIONS
A very large proportion of the substances which are
prohibited in horseracing are those substances that
reduce the pain of injury and associated inflammation.
Responsible and controlled treatment with anti-
inflammatory, antipyretic and analgesic substances
play an important role in the correct recovery
procedure. From a welfare perspective, the use of
such substances as a masking agent is considered to
be cruel as they may well aggravate an underlying
injury.
Humans also experience such pain with injuries
such as cuts, abrasions, bumps, sprains and strains.
Since humans are in a position to self-medicate using
substances responsibly, there is a significant need for
such substances to be available in preparations that
are accessible in shop fronts and that are affordable.
Problems arise inadvertently when such preparations,
available without the requirements of medical
consultation and prescription, enter the stable yard.
The ease in obtaining these preparations does not
suitably emphasize the fact that they are prohibited in
racing. It is also unclear what constitutes a prohibited
substance dose for a horse when using a preparation
intended for humans and how this could result in a
prohibited substance positive.
Within this document a warning is issued with
regard to the use of such prohibited substances
and preparations that are readily available. When
these preparations are used in the horse they enter
the bloodstream including those that are topically
administered. This affects the horse, not only where
it was administered, but also systemically (within
20
other parts of the body). It is critical that the dose and
elimination rate of the particular substance is carefully
investigated and considered, with the required
veterinary guidance and advice, in combination with
a sufficient withdrawal safety
margin.
• Salicylic acid and salicylic acid (salicylate)
derivatives: These preparations typically
contain either salicylic acid or acetylsalicylic
acid (e.g.Aspirin), methyl salicylate (e.g. Sloan
Deep Heat and Rigly’s Horse Liniment) or
dimethylamine salicylate (e.g. Reparil gel).
The withdrawal period of such substances is
recommended to be at least 36 hours. If repeated
doses or high doses are used then this period
must be increased.
• Dimethyl sulfoxide (DMSO): This is an oily
substance and it is an analgesic and anti-
inflammatory. This substance however also
forms part of some topical preparations, with
the function to increase the absorption of other
substances. The withdrawal period for DMSO
prior to racing is at least 48 hours.
• Paracetamol: This natural pharmaceutical is
contained in some components of horse feed.
As a result it is found in the specimens of
most horses. Pharmaceutical preparations of
paracetamol include a variety of pain (headache)
and antipyretic (fever reducing) human
medications. Paracetamol is not recommended
for therapeutic use in horses. As a high dose is
required for a desired effect in the horse, the
administration of paracetamol may result in a
highly elevated level of this substance, which
would result in a positive finding.
• Equine Health Update •