Vet360 Vol 3 Issue 04 August 2016 - Page 37

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. Issue 04 | AUGUST 2016 | 37 VET360 AUGUST 2016 working.indd 37 2016/07/25 11:04 PM