DERMATOLOGY
CALCINOSIS CUTIS: Calcinosis cutis is a collective
description for a group of conditions that result in
pathological calcification in the skin. These include
dystrophic calcification (seen with hyperadrenocorticism and diabetes mellitus), metastatic calcification
(seen with renal insufficiency) and it may be idiopathic
(calcinosis circumscripta). Skin lesions are usually firm,
cutaneous or subcutaneous nodules.
There is no typical distribution pattern but foot pads
are commonly involved. Several cases of foot pad
calcification have been reported in small dogs with
renal dysplasia. The lesions usually develop after or
at the same time as other signs of renal insufficiency.
Diagnosis is based on skin and renal signs, histopathology of skin biopsies and further tests to evaluate
the kidneys (serum chemistry, urine examination, ultrasound). The prognosis is guarded in most cases depending on the cause of the renal disease.
Calcinosis cutis
(Gross TL. 1997.
Calcinosis circumscripta
and renal dysplasia in a
dog. From: Veterinary
Dermatology 8(1): 27
– 32)
FOOT PAD BURNS: Chemical and thermal superficial
foot pad burn wounds may present with varying loss
of epidermis and dermis. These wounds are treated
with topical silver sulfadiazine cream and bandaged
with a non-adherent, semi-occlusive bandage. Initially, daily wound dressing and bandage change is recommended. For superficial burns, re-epithelialization
may be complete by seven to nine days. With deeper
injuries, healing may take up to 21 days, depending on
the size of the wound.
FOOT PAD FROST BITE: When the environmental
temperature drops below 0°C, blood vessels close to
the skin start to constrict to preserve core body temperature by diverting blood toward the core and away
from the cooler parts of the body. This can reduce
blood flow in some areas of the body, especially the
extremities, to critically low levels. The combination of
cold temperature and reduced blood flow can allow
the tissues to freeze, causing severe tissue injury. The
paws, ears and tail are the most common tissues to be
affected. If a dog is wet or damp, these areas are more
vulnerable to frostbite.
The initial clinical signs associated with frostbite include
discoloration (pale, grey, blue), coldness and swelling
of the affected area, pain, blisters or skin ulcers and
areas of blackened or necrotic skin. As frostbitten tissues thaw, they may become red and very painful due
to inflammation. The clinical signs of frostbite may
take several days to appear. Severely frostbitten areas
will become necrotic, die and slough off. During this
time secondary bacterial infection commonly occurs.
Diagnosis is usually based on the history and clinical
findings. Treatment is symptomatic and may include
treatment for shock and pain. Antibiotics are used to
prevent secondary bacterial skin infections.
The prognosis for frostbite depends on the extent of
the injuries. Mild cases of frostbite usually resolve with
little permanent damage while more severe frostbite
may result in permanent disfiguration or alteration of
the affected tissues. Amputation of a severely affected
body part may even be required.
Foot showing burns
of the footpads (http://
livewagbark.com/wpcontent/uploads/2015/0
7/5751084148_5085e13
502_b.jpg)
Foot showing frostbite (http://www.famouschihuahua.com/
chihuahua-health-concerns/winter-paw-care/)
FOOT PAD TRAUMA: Foot pad trauma is one of the most common causes of foot pad lesions. Examples are lacerations as a result of sharp trauma or blisters, abrasions and erosions which are frequently found in dogs who accompany their owners jogging on hard surfaces, on hot tar or who obsessively play tug-of-war. Superficial and full thickness
injuries to foot pads generally heal in a similar fashion when compared to other skin surfaces, however they heal more
slowly and with more complications.
Injured foot pads are exposed to contaminated surfaces, self-trauma and excessive motion and tension and are difficult to prepare aseptically. As a result, contamination of foot pad wounds is more common. Most superficial pad
lacerations heal without complications, regardless whether they are repaired or not, if bandaged appropriately. Full
thickness pad lacerations should be repaired with a two-layer technique and bandaged to relieve motion and pressure
on the repair.
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