16/4/2010
Treatment of corns
Compiled by the Australian Greyhound Veterinary Association
Aetiology
1. Trauma to the pad from objects such as stones. This causes some haemorrhage into
the deeper layers of the pad with subsequent thickening of the pad tissue
2. Penetration wounds into the pad usually from glass or other sharp objects.
Pathogenesis
Alteration of the normal tissue structure of the pad produces a thickening of the pad.
Direct trauma produces a more superficial thickening of the pad tissue
Penetration wounds induce conical shape lesion with the base being on the pad
surface and the apex directed into the pad. The apex of the corn may be in direct
contact with the insertion of the deep flexor tendon onto P3. There may be a small
vascular supply to the apex of the corn.
Clinical signs
 Thickening of the digital pad
 Firm tissue palpable in the pad
 Pain on application of pressure across the pad, and pressure directly onto the corn.
 Lameness.
 Penetration wound may be present.
 Lightly shaving the surface area of the corn to remove a thin layer of superficial
pad tissue and application of methylated spirits may more clearly outline the
affected tissue. Sometimes a white ring may be noted around the corn.
Diagnosis
 Clinical signs
 History
 Imaging.
Imaging
Lateral, A/P and oblique radiographs should be taken to ensure there is no foreign
body present in the pad.
Reduced exposure levels can be used to more clearly outline the corn tissue.
Anaesthesia
Superficial corns can be treated under sedation and or using digital nerve blocks.
Deep corns should be removed under a general anaesthetic.
Esmarks type bandages should be used to control bleeding in all corn surgery.
Treatment of superficial corns
Non surgical
Chemical cautery using compounds such as silver nitrate, ferric chloride or salicylic
acid ointments can be applied to the corn and then the dead tissue is shaved back
every 3-4 days to get down to the next layer of affected pad. This process is repeated
until the pad is normal and it may take several weeks to resolve. The foot must be
kept bandaged during the treatment.
Surgical
The thickened pad tissue is shaved from the surface of the corn. Sharp scalpel blades
must be used (sizes 21 and 23) and it may be necessary to change the blade after the
thicker tissue has been trimmed.
If a small area of the apex of the corn can be visualised then it may be excised using a
size 11 scalpel.
Once the surface pad tissue has been removed the pad will start to bleed and so the
Esmark’s bandage is necessary.
When all the thickened tissue has been removed the pad is bandaged until the tissue
has healed.
Treatment of deep Corns
Either ventral or lateral approach may be made.
Some surgeons report success using electro cautery to excise the corn tissue. Most
surgeons prefer to use scalpels.
1. Ventral (Plantar or palmar)
The corn margins are visualised and an elliptical incision is made around the margins
in an anterior posterior orientation. The blade is angled to the midline of the toe so
that a wedge of tissue is removed.
It is best to take the wedge down to the level of the flexor tendon insertion so as to
ensure that all of the corn has been removed.
If the apex is not completely removed the corn may reform.
The pad tissue is then closed with several preplaced sutures of 4/0 – 6/0 monofilament
suture material.
Alternatively the wound may be left open to heal by granulation.
The foot is bandaged until healing has occurred.
2. Lateral
An incision is made just below the skin pad junction and the pad is reflected to allow
visualisation of the apex of the corn. The corn is then excised and either the wound
left open to granulate or it is closed with several preplaced sutures of 4/0 – 6/0
monofilament suture material. The sutures then pass through the skin and the pad.
The lateral approach allows for better visualisation of both foreign bodies and the
corn apex.
Post operative care.
The wounds must be kept dressed for 2-3 weeks until the pad has healed. Care must
be taken when bandaging a greyhound’s foot to ensure that the toes are well padded
so as to prevent pressure sores developing.
Wounds which are left open to granulate should be dressed with Calcium Sodium
Alginate dressings (Kaltostat®), or similar dressings. These dressings should be
changed every 3 days.
Sutured wounds are dressed with a non adherent dressing such a Melolin®. These
dressings should be changed every 5-7 days. Sutures are removed at 2-3 weeks. The
superficial layers of the pad adjacent to the suture line will always need to be trimmed
back from the line at the time of suture removal. The foot should be kept bandaged
until the pad tissue has gained sufficient strength to be able to bear weight. At this
stage a lighter dressing using a sock or tape may be used.
Owner compliance is always a major problem and must be fully assessed at the time
of surgery. Wet bandages from urine or other sourcesis a very common problem.
Corns in Dogs: Signalment, possible
Aetiology and response to surgical
treatment
Guillard et al JSAP (2010) 51. 162168
Objectives : To describe the signalment and response to surgical
treatment, and to propose aetiopathogenetic mechanisms for the development of
paw pad corns in dogs.
METHODS; A combined retrospective and prospective study
was conducted on 30 dogs that presented with paw pad corns. The age, breed
and gender of the dogs, together with anatomical positions of the corns were
recorded. Surgical treatments involved either excision (n727) or distal digital
ostectomy (n-3), The minimum follow-up period was one year,
Results: The age at presentation was from two to 15 years. All
the breeds in this study were either greyhounds or sighthounds. Males were
aver-represented. Ninety percent of the corns were found in the digital pads
of digits three and four, and 9096 were found In the thoracic limbs. The
evidence suggests a mechanical aetiology or foreign body penetration. Longterm response to surgical excision resulted in a recurrence rate of more than
5096 (n=27). Distal digital ostectamy gave good results in selective cases
(n=3).
CLINICAL SIGNIFICANCE. Corns can cause severe
chronic lameness In greyhounds and related breeds. Long-term response to
surgical treatments is disappointing but it is recommended as an initial
treatment as it can be curative.