Feet First®: Functional Sow Claw Trimming

Claw trimming has been shown to benefit sows that experience lameness caused by unequal weight bearing on overgrown toes and dew claws. To control claw horn overgrowth and help limit lameness, it is necessary to trim the claw and restore normal conformation and weight distribution. In addition, correction of existing claw lesions may further benefit sow performance. 

Sow Claw Trimming 

  • Proper trimming cannot be done unless the animal is adequately restrained and poses no danger to inflict injury to itself or the trimmer. A well-designed chute that is safe for sow and operator is required. 
    • The Feet First® Chute, from Zinpro Corporation, utilizes a patent-pending design to safely restrain sows during claw trimming. It gently, quietly and efficiently raises sows off the ground, providing easy access to the foot for examination and trimming. For more information about the Feet First Chute, contact your local Zinpro representative.  
  • Trimming equipment includes a small angle grinder with a very coarse sand disc, a pair of hoof nippers and a sharp hoof knife used for corrective trimming of claw lesions.  
  • The whole foot, including the interdigital space, should be cleaned and inspected and lesions recorded. Proper identification of lesions is important in order to make appropriate adjustments according to cause.

4-Step Claw Trimming Technique

Claw trimming is designed to help control claw horn overgrowth and help limit lameness by restoring normal conformation and weight distribution. Following is an overview of the 4-Step claw trimming technique developed by the Feet First® team.

Step 1

Step 1: Trim the Toes

  • Use nippers to reduce toe length. Do this in several increments, inspecting the end of the toe after each cut to determine if another cut can be done safely.
  • The ideal toe length is about 50 mm.
  • With some sows, there may be one overgrown toe on the foot, and one very short (stunted) toe. In these cases, you may not be able to reduce the long toe to match the length of the short toe.

Step 2

Step 2: Straighten the Wall

  • Toe overgrowth often curves or buckles the dorsal wall, making it concave.
  • Use the angle grinder to straighten the wall by removing excess wall horn below the area where buckling occurs.
  • The wall should be straight from the coronary band to the bearing surface.

Step 3

Step 3: Balance the Sole and Heel

  • Use the grinder to reduce the sole depth. The objective is to have a flat and level sole area across both claws for functional weight bearing of the foot.
  • It is common for the outside (lateral) claw to be more overgrown than the inside (medial) claw, so the lateral claw will need more sole horn removed. The medial claw often only needs flattening, with minimal sole horn removal.  
  • If the heel is overgrown, remove soft tissue with the grinder or hoof knife. The outside heel is often more overgrown than the inside heel, but with care these can be made even (except in cases where the inside heel is small and underdeveloped).
  • The heel should not be trimmed all the way flat to match the sole, as it acts as a ‘first impact’ shock absorber when the sow walks.

Step 4

Step 4: Trim Dew Claws

  • Overgrown dew claws are prone to injury and can interfere with normal locomotion of the sow.
  • An ideal dew claw horn should be approximately 20 mm long.
  • Use the nippers to reduce dew claw length. Do this in increments until a satisfactory length is obtained. 
  • Use the angle grinder to round off the end of dew claws.

Good Foot Example

  • Use a sharp hoof knife to remove loose and undermined horn to the point where reattachment of the horn with the underlying tissues becomes evident. This procedure should be done with care as to avoid damage resulting in hemorrhage and damage to the underlying corium. 

Caution: Do not draw blood from the claw when trimming. If you draw blood, you have trimmed too aggressively and have penetrated the corium. It is better to leave a little extra horn than to remove too much.