International Dairy Topics — Volume 13 Number 1 11

by Andrea Fiedler, veterinarian andresearcher, Rainer Hoefler and MarkusStumpf, hoof trimmers, Germany.

There are two main subjects to discusswhen talking about thin soles of cattlehooves. On one hand an abrasive

floor, particularly a new one, can cause mas-sive abrasion of sole horn. On another,excessive hoof trimming is frequently acause of thin soles. Without immediate intervention somecows will lose their complete sole, andcorium will become uncovered, especially atthe tip of the toe. Being close to the bonethis area is very vulnerable for ascendinginfections leading to progressive, life-threat-ening inflammations. Another problem is painful soles caused bylaminitis – cows show extreme gait prob-lems and also need urgent relief of load onaffected claws.To preserve the sole and the animal fromfurther deterioration, veterinarians and hooftrimmers often recommend immediatehousing on soft ground like straw or rubbermats.Covering the hooves with padded dress-ings is also possible, but walking on concretewill destroy the dressing within one or twodays. Therefore, it is necessary to search fora useful and practical solution. To preventsore feet in horses fast setting adhesives canbe used under the sole, so why not in cows?Now a perfect method is available, whenthe corium is still not affected.

Let cows walk again

The invention of a flexible block is a solutionto the problem. These soft blocks can befixed on healthy inner claws (hind leg), butalso on all inner and outer claws.Up to now softer blocks were made ofrubber or polyurethane. The elastic compli-ance was limited, and was often combinedwith a hard glue. The new flexible Walkeaseblocks from Shoof International Ltd,Cambridge, New Zealand, are made of eth-ylene-vinyl acetate (EVA) with Shore hard-ness A 70 (± 2). These soft blocks feel like firm sponge rub-ber and are flexible. They are fixed with aspecial Walkease adhesive. Different sizescan be identified by different colours, thelargest size is blue and white.White Wedgie blocks are also available toraise the heel slightly – not recommendedfor thin soles, but in case of sole ulcers andother problems in the hind area/bulb areaof the hoof (previous research).These soft blocks can be fixed under soleswithout any problems even when the sole isvery thin or affected by laminitis (even ifthere is some pain reaction). A good way toprevent further abrasion is the attachmentof one block on each inner and outer claw –at an early stage – before the corium isexposed!A sole as flat as possible is necessary, sothe horn has to be trimmed very carefully.The additional use of the Walkease raspprovides the correct surface for theWalkease block to adhere to.

Choose the correct size that will supportthe whole hoof wall. At the hind end of thesole the block must support the heel bulb,and therefore it is necessary to use blockswhich are longer than the load-bearing sole.The block should overlap the sole byapproximately two-finger width (half of softbulb), otherwise there may be too muchpressure under the area of typical soleulcers.In recent research a wedge form of hoofblock had achieved best results for loadrelease and locomotion score. WalkeaseWedgies are available, made of the sameflexible material (these should not be usedwhen there is exposed corium or ulcersunder the tip of the toe.) In general the large blue/white-colourWalkease block (120mm long and 20mmhigh) has the best shape (the material can betrimmed if necessary).

Super glue

One of the advantages of the Walkease sys-tem is the Super Glue type adhesive with itsshort time for setting. The glue activatesvery quickly (after 5-10 seconds or so) andthe foot can then be set down. The weightof the cow is necessary to bring the glue toits perfect adhesive properties, and thisshould be done before the glue has curedcompletely. This cyanoacrylate adhesive is activated by

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Successful treatment of thin solesin dairy cows

Thin sole lesion presenting.

Thin sole apparent in cross-sectionedhoof – showing opening to infectedcorium.

Using a hoof tester to detect pain areasof thin soles.

12 International Dairy Topics — Volume 13 Number 1

moisture, so the hoof should never be driedartificially (air gun or alcohol, etc). The nat-ural hoof moisture is what activates the glue.Damp conditions are no problem. In extremely cold weather, when the air isvery dry, the activation can be assisted bybreathing deeply onto the glued block,before attaching it to the hoof (the glueshould be carried in your pocket). Using a fast-setting polyurethane adhesivewill not reliably fix these prosthetics. In poorconditions the blocks will fall off after a fewhours.

Fitting procedure

Treatment of the injured claw must be com-pleted first and then the healthy claw is pre-pared for fitting the block. In case of thinsoles because of excessive abrasion a flexi-ble block should be fixed on both hoofs –the inner and the outer. Trim the surfacecarefully, especially when the sole is thin. At least one third or a half of the sole mustbe as level as possible to give enough adhe-sive surface. The flexibility of the blocks per-mits an adapation to slight unevenness. Now use the Walkease hoof rasp (sup-plied in the kit) or a rasp for wood to pre-pare the healthy claw – even if a grinder orother cutting tool has been used to preparethe claw. The rasp provides the correct flat andclean surface for the Walkease block toadhere to. Do not dry the hoof artificially inany way. Test the Walkease block for size andshape on the healthy claw. Choose the cor-rect size that will support the whole hoofwall. Handle the Walkease block carefullyensuring the gluing face is kept perfectlyclean (every Walkease block is individuallywrapped in plastic to ensure that it is keptclean before use.) To avoid getting glue on hands, it is essen-tial that you wear gloves during this proce-dure. Apply glue sparingly to the Walkeaseblock. Do not use excessive glue (2ml maxi-mum). To wipe excessive glue off with aspatula if over-applied is recommended.There are two parts necessary to bring theglue to its perfect adhesive properties:l Press the block very firmly onto thehealthy claw. According to the manufactureryou will feel the block ‘grip’ after about 5-10seconds of steady pressure (possibly up to20 seconds in very cold or very dry condi-tions with low humidity – for examplebelow freezing). l Drop the leg carefully down for the cowto put weight on the block. This part is acrucial point. The Walkease block will notattach securely if weight is not appliedbefore the glue has completely set. This partis most important. The glue sets very quicklyunder the animal’s full weight. The excessglue is squeezed out and the block conformsto the claw surface. This improves the sur-

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Final preparation of hoof for Walkeaseapplication.

Application of Walkease adhesive on athin sole.

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face area contact giving a stronger bond. Invery cold weather the bond time mayincrease a little, so in these conditions givethe animal a little longer standing on theblock before releasing it from the crush.

Durability

Wooden blocks are very useful in tied hous-ing. In loose housing systems they areexposed to quick wear, depending on thefloor surface. So the blocks are not flat any-more and pressure damage to the hoof canoccur. Blocks of rubber or polyurethane,and other hard plastic blocks seem to have

higher abrasion resistance. Some blocks areformed with depressions, where stones ordung could cling, The rear end of theseblocks often deforms because of the weightstress. Walkease show a slight loss of heightduring 10-20 days. The rear end of theseblocks often deforms towards the bulb, butthey stay soft and so they stay comfortablefor the cow. Nearly almost no wear occurs.

Removal

Normal hard blocks have to be removedafter 3-4 weeks to prevent further injury tothe animal. It can then be necessary to trim

the hoof again and fix a new block (a currentstudy shows problems of horn growthunder blocks after that time). It is also quitenecessary to remove hard lumps of glue thatmay be left under the hoof after de-applica-tion of hard blocks. It is an empirical fact that farmers often donot remove blocks, so a self-releasing sys-tem is very interesting. Walkease blocksgenerally do not require removal. The adhesion of walkease is very good forone to three weeks. Some blocks remainlonger – up to 40 days. Walkease in theslurry pit usually are not a problem. Longlasting blocks can easily be removed byusing a nipper or pliers. n

Using brief pressure to stick Walkeaseblock.

Outer claw bandaged, inner clawblocked.

Good treatment when all the soles arethin.