By Richard Laven (BVetMed PhD MRCV) – Massey University Farm Services, New Zealand.
Hoof blocks are a crucial part of the effective treatment of cattle lameness due to claw horn problems such as white line disease. While corrective hoof trimming alone can reduce weight bearing in the affected claw, using a hoof block is more effective in preventing weight bearing (therefore, reducing pain) and increasing the healing rate. Hoof blocks are also effective when used on cows that have not been lame for very long. Therefore, in cases of treating lame cows with claw problems, the question should be ‘Why should I not use a block?’ rather than ‘Should I?’. That is, unless there is a good reason to not use a block, and every lame cow with a claw problem should get one.
There are three types of block on the market; plastic blocks with a shoe design (such as the CowSlip), wooden/hard plastic or rubber blocks which are a flat hoof-shaped block (e.g. Bovi-Bond or FuturaPad), and soft EVA blocks (Walkease). Ideally, we want a block to last 3-4 weeks before coming off, and of the three types only the first two (the ‘hard’ blocks) will last for this period of time. So if you have a damaged claw and the other claw on the same hoof is normal, you should always use one of the ‘hard’ blocks. Currently, there is very little evidence as to which type is best other than shoe-type blocks probably stay on slightly longer than standard flat blocks. This is unlikely to be clinically significant in most cases, so basing the choice of block on personal preference is perfectly acceptable.
If the non-lame claw is also damaged, then putting a hard block on the non-lame claw can produce more problems than it solves. This could include causing pain and discomfort, delaying healing and damaging the ‘non-lame’ claw. Removing the hard block one or two weeks after putting it on can also be difficult and cause the cow more pain. Therefore, the recommendation is not to use blocks in cases where there is also damage to the non-lame claw, or to shape the block so that pressure is not put onto the affected area (e.g. the white line if both claws have damaged white lines).
The advent of the soft Walkease means that blocks can be used even if the non-lame claw has some damage. The soft block dissipates the pressure so damages the non-lame claw less and is easy to remove. Therefore, I would recommend, except in exceptional cases, using a Walkease block where the non-lame claw is not strong enough to take a hard block. If the cow doesn’t respond as well as hoped, then it is easy to pick the foot up, take the block off and examine the sole of the non-lame claw. Walkease do not last 3-4 weeks so are probably not appropriate for severe cases. However, for mild cases, especially farmer-treated cases, they can be very useful especially if the cow is observed closely. Should the block get lost or worn down, the foot is picked up and the Walkease easily replaced (or a hard block applied) if the claw problem has not resolved completely.