INTERDIGITAL CYSTS

  INTERDIGITAL CYSTS


In between the fingers of the paws you notice some abscesses that grow in size when liquid or pus accumulates. This is probably due to an infection that has access to the tissues under the skin. Before the abscesses appear, the dog insistently licks his paw between the fingers. A short while later, he starts to limp due to the pain he feels, and as the tumefaction increases, he won't let you examine his paw. After a few days the abscesses pop, releasing pus and blood, thus alleviating the pain. As long as there are no complications, these heal normally and the animal recuperates completely. Nevertheless, they tend to reappear in one or more paws. Humid fomentations (do not burn) help evacuate the pus faster. You can also form a cataplasm of bread crumb soaked in hot milk. Once you have gotten rid of the pus, clean really well, apply an antiseptic and bandage it well so that it doesn't get infected. It is always convenient to consult the vet in order to avoid that from happening again and so you can find the cause. "Interdigital dermatitis" can be the beginning of an "interdigital pioderma", which can give way to deep furuncles all over the paw.

  INTERDIGITAL FURUNCULOSIS


Interdigital furuncles, often incorrectly referred to as interdigital cysts, are painful nodular lesions located in the interdigital webs of dogs. Histologically, these lesions represent areas of nodular pyogranulomatous inflammation—they are almost never cystic.

Etiology: 
The most common cause is a deep bacterial infection. Many dog breeds (eg, Shar-Pei, Labrador Retriever, English Bulldog) are predisposed to bacterial interdigital furunculosis because of the short bristly hairs located on the webbing between the toes, prominent interdigital webbing, or both. The short shafts of hairs are easily forced backward into the hair follicles during locomotion (traumatic implantation). Hair, ie, keratin, is very inflammatory in the skin, and secondary bacterial infections are common. Less commonly, foreign material is traumatically embedded in the skin. Demodicosis ( Mange in Sheep and Goats) may be a primary cause of interdigital furunculosis. Canine atopy ( Allergic Inhalant Dermatitis: Introduction) is also a common cause of recurrent interdigital furunculosis. 

Clinical Findings and Lesions: 
Early lesions of interdigital furunculosis may appear as focal or generalized areas of erythema and papules in the webbing of the feet that, if left untreated, rapidly develop into single or multiple nodules. The latter usually are 1-2 cm in diameter, reddish purple, shiny, and fluctuant; they may rupture when palpated and exude a bloody material. Interdigital furuncles are most commonly found on the dorsal aspect of the paw, but may also be found ventrally. Furuncles are usually painful, and the dog may be obviously lame on the affected foot (or feet) and lick and bite at the lesions. Lesions caused by a foreign body, eg, a grass awn, are usually solitary and often occur on a front foot; recurrence is not common in these cases. If bacteria cause the interdigital furunculosis, there may be several nodules with new lesions developing as others resolve. A common cause of recurrence is the granulomatous reaction to the presence of free keratin in the tissues. 

Diagnosis: 
This is often based on clinical signs alone. The major differential diagnoses are traumatic lesions and neoplasia, although the latter is rare. The most useful diagnostic tests include skin scrapings for Demodex mites, impression smears, or fine-needle aspirates to confirm the presence of an inflammatory infiltrate. Unusual or recurrent lesions should be excised for histopathologic examination. Solitary lesions may require surgical exploration to find and remove foreign bodies such as grass awns. 

Treatment: 
Interdigital furuncles respond best to a combination of topical and systemic therapy. Cephalexin (20 mg/kg, PO, tid, or 30 mg/kg, PO, bid) is recommended for 4-6 wk of initial therapy. However, because the lesions are pyogranulomatous, it may be difficult for antibiotics to penetrate them; therefore, >8 wk of systemic antibiotic therapy may be required for lesions to completely resolve. These lesions are often complicated by concurrent Malassezia spp infections. Oral ketoconazole or itraconazole (5-10 mg/kg) for 30 days may be indicated. The presence of Malassezia can be documented by cytologic examination of nail bed debris and/or impression smears of the skin. Topical foot soaks in warm water with or without an antibiotic solution (eg, chlorhexidine) and the application of mupiricin ointment are recommended. Some dogs may benefit from antibiotic wraps and bandaging. Antihistamines given for the first several weeks of treatment may partially alleviate pruritus, if present. Glucocorticoids are contraindicated. 

Chronic, recurrent interdigital furunculosis is most often caused by inappropriate antibiotic therapy (too short, wrong dose/dosage, wrong drug), concurrent corticosteroid administration, demodicosis, an anatomic predisposition, or a foreign body reaction to keratin. Lesions that recur in spite of therapy can also be a sign of an underlying disease, eg, atopy, hypothyroidism, or concurrent Malassezia infection. Lesions in confined dogs are likely to recur unless the dog is removed from wire or concrete surfaces. In some chronic cases, surgical excision or surgical correction of the webbing via fusion podoplasty may be needed. Alternatively, pulse antibiotic therapy (full dosage therapy 2-3 times/wk) or chronic low dosage antibiotic therapy (eg, 500 mg/dog, PO, sid) may help maintain clinical remission and provide pain relief in dogs with chronic lesions. This therapy is recommended only when the inciting cause cannot be identified (eg, idiopathic pyoderma), treated (eg, anatomic predisposition), or resolved (eg, chronic infection caused by foreign body material or keratin). 


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  INTERDIGITAL DERMATITIS

Interdigital dermatitis is an inflammatory, irritating dermatitis between the toes. Applying of astringent agents such as mercurochrome or gentian violet will dry out the infected areas. Prevent the dog from licking the infected areas by using an Elizabethan collar or a bucket. You may have to consult a veterinarian when antibiotics and antihistamine injections are necessary.

    INTERDIGITAL PROBLEMS IN DOGS - Pemphigus

Interdigital skin is the skin between the toes. Allergies, irritants, bacteria and fungi, and parasites can infect this area. Dogs with Allergic Inhalant Dermatitis usually lick their feet excessively, which causes a characteristic rust-coloured discoloration to the feet. External irritants are also a common problem. Lawn chemicals and herbicides as well as pebbles and hot road tar are often incriminated. Walking on recently cleaned carpets is also irritating. Interdigital skin is also affected by Demodectic mange, certain bacteria and a variety of fungal infections.

Pemphigus is a type of skin disorder that may involve the footpads. The bridge of the nose, especially sunburned noses, and the eyes are also often involved. Pemphigus is associated with a defect in protective immunity in dogs and humans. Secondary bacterial infections are common. The skin is sore and covered with cysts as well as pus-filled sores.

SIGNS

  • Constant licking and chewing of the feet.

  • Saliva from constant licking causes rust-coloured discoloration to white paws.

WHAT YOU AND YOUR VET CAN DO

  • Epsom salt soaks are soothing. Cotton socks prevent sore feet from further irritation.

  • Rinse the feet off with water to decrease exposure to irritants like salt and de-icing chemicals used in winter. Keep a spritzer bottle by the door and use it every time the dog comes inside, then dry his feet off with a towel.

  • Trim excess fur between the toes and remove mats between the footpads.

  • Diagnosis for Pemphigus is confirmed by a skin biopsy. Treatment is geared at symptomatic relief of foot lesions, antibiotics to eliminate secondary bacterial infections, and immune system stimulation.

COMPLEMENTARY TREATMENTS

HERBAL REMEDIES

Immuno stimulant herbs include Echinacea, Reishi, Astralagus, Maitake, Shitake, Ashwaganda, and Ginseng.

HOMEOPATHIC REMEDIES

Sulphur 30c given twice daily provides some relief of local irritation. Immuno stimulant vitamins include Vitamin A and Vitamin E.

   LINKS TO RELATED ARTICLES

 

 

| Nail Conditions | Trimming Tools | Nail Trimming Procedure | Nail Clipping Article Links |
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