Farriers have used formalin for many years to harden horses' hooves. The action of formaldehyde on keratin is well known to be a simple cross-linking action. Methylene or bis-thioether groups are added by condensation reactions with reactive amino, sulphydryl or other groups on the keratin helix to form additional linkages to reinforce the rather labile disulphide links which occur naturally. It is quite incorrect to say that formalin hardens horn by removing water. Rather, it strengthens it by introducing these extra inter and intra-molecular links.

However, formaldehyde in its simple aldehyde state reacts too quickly. It case-hardens the hoof, thus preventing the entry of formalin to deeper layers, and also creating surface brittleness. Keratex Hoof Hardener contains formalin. It also contains another substance which effectively slows down the reactivity of the -CHO group, thus giving time for the aldehyde to penetrate the outer layers of horn. This is facilitated by the presence of yet another compound in Keratex Hoof Hardener which temporarily modifies the hydrogen bonds which join the helix coils internally and externally. Having done this, the compound then evaporates, leaving the hydrogen bonds to re-make once the aldehyde is in place.

Keratex Hoof Hardener also contains an inorganic complexing agent. One end of the molecule of this agent co-ordinates onto a nitrogen atom in the keratin molecule. The other end modifies the keratin helix, thus effectively adding an aggregate to stiffen the horn. This process resembles the consolidating effect of the melanin in hoof horn. The melanin also acts as an aggregate and confers extra strength.

Finally, Keratex Hoof Hardener contains a plasticiser to stop the horn from becoming brittle, and it also contains a powerful disinfectant to assist in maintaining general hoof health.

User Notes - Sold in 250 ml plastic bottles. Includes separate hoof brush for application.

Apply to lower half of hoof and sole, avoiding coronary band and frog.

Use daily for one week then twice weekly for general hoof maintenance.

If the hoof has been treated with any oils or greases over the past three months, degrease the hoof thoroughly with acetone before applying Keratex Hoof Hardener.  Do not use any oils or greases while using Keratex Hoof Hardener. 

Helpful hint: Pour from the bottle into the cap and work out of it to avoid getting dirt back in the bottle or spilling it.