Despite careful ingredient screening for aflatoxin, low
concentrations may get into your petfood undetected. A clay
called HSCAS (Novasil) can provide you with better assurance of
Recent research at Texas A&M University has established
better ways to inactivate aflatoxins. Earlier this year, dozens
of dogs in the US died after eating aflatoxin-contaminated,
commercial petfoods. The use of HSCAS could have prevented
Aflatoxin is a naturally occurring mycotoxin produced by two
types of mold: Aspergillus flavus and Aspergillus parasiticus.
Aspergillus flavus is widespread in nature and is most often
found when certain grains are grown under stressful conditions
such as drought.
Aflatoxins are potent liver toxins and carcinogens.
Suppression of the immune system is also a common effect. Among
the various mycotoxins, aflatoxins have been the subject of the
most intensive research. The losses sustained from companion
animal toxicity and death are incalculable.
Aflatoxin control measures include using genetically
engineered, resistant crops and ensuring appropriate storage
conditions. These precautionary steps are followed by careful
testing of susceptible commodities for aflatoxins and banning
the lots that, in the US, exceed the regulatory action level of
20 parts per billion for aflatoxin B1. It is the most toxic
type and is regarded as the "sentinel" substance for all other
aflatoxins. HSCAS clay has lately been shown to be a good
In a presentation at Petfood Forum 2006, Timothy Phillips,
PhD, summarized research in his lab at Texas A&M
University. It has focused on the development of innovative
sorption strategies for the detoxification of aflatoxins. In
particular, the lab has employed isothermal analyses and
molecular modeling techniques to characterize and design
clay-based materials for the enterosorption, and inactivation,
of aflatoxins in the gastrointestinal tract.
Hydrated sodium calcium aluminosilicate (HSCAS) has been
shown to prevent the adverse effects of aflatoxins in various
animals when included in the diet. Studies have also confirmed
that HSCAS can alter the bioavailability of aflatoxin in dogs
(Bingham et al., Food Chem. Toxicol., 2004). Fortunately, HSCAS
does not interfere with the utilization of vitamins and
micronutrients in the diet. However, it is important to note
that it does not protect animals against other mycotoxins.
Clay minerals are structurally and chemically diverse. Many
are ineffective and/or nonselective for aflatoxins. Based on
the Texas research, all aflatoxin sequestering agents should be
rigorously evaluated in vitro and in vivo and should meet the
Efficacy in multiple animal species;
Safety in long-term studies;
Negligible interactions with vitamins and
Favorable thermodynamic characteristics of ligand sorption;
Tolerable levels of priority metals and dioxins/furans.
HSCAS is commonly used as an anti-caking agent in animal
feeds. It tightly and selectively adsorbs aflatoxin. The
following is an abstract from Bingham et al., Food Chem.
In a crossover study, six dogs were randomly fed a
commercial dog food (no-clay control) or the same commercial
dog food coated with HSCAS (0.5% by weight). These dogs were
administered a subclinical dose of aflatoxin B1. Diets were
switched and the process repeated. The HSCAS coated diet
significantly reduced urinary aflatoxin M1 by 48.4%Â±16.6 SD
versus the control diet.
The conclusion: HSCAS protects dogs fed diets with even
minimal aflatoxin contamination. Despite regular and careful
ingredient screening for aflatoxin, low concentrations may
reach the final product undetected. Therefore, HSCAS may
provide the petfood industry further assurance of canine diet
Aflatoxin management systems ultimately function like an
insurance policy. Not every facility requires the same
insurance plan. It is important to tailor a mycotoxin
management program to fit the needs of individual