The mineral composition of nails in normal dogs and comparison with shed nails in canine idiopathic onychomadesis

Canine symmetrical lupoid onychomadesis in bearded collies

BACKGROUND

Symmetrical lupoid onychomadesis (SLO) is a disease not infrequently seen in bearded collie dogs in Germany.

OBJECTIVES

The aim of this study was to compare historical and clinical data, as well as the mineral content of the hair and claws of bearded collies with SLO with that of normal control dogs.

ANIMALS

Twenty-eight affected bearded collie dogs and 39 control dogs.

METHODS AND MATERIALS

Owners completed an extensive questionnaire regarding upbringing, environmental conditions and diets. Claw specimens were obtained by claw trimming or gathering lost claws; hairs were obtained by plucking samples from several areas of the body; samples were converted to ash and evaluated in an atomic absorption spectrophotometer.

RESULTS

Clinical signs in affected dogs eventually involved all claws on all paws. In twelve dogs recurrence of onychomadesis was observed. There was no relevant association between gender, housing, diet and health management, physical stress and the development of SLO with exception of the age at which more intense exercise began. The most commonly used treatment combination was fatty acids, pentoxifylline and tetracycline; improvement occurred in 17 animals. Calcium, sodium and phosphorus concentrations were higher in the claws of affected dogs, whereas zinc concentrations were lower. The mineral content of hair samples of the affected dogs was not significantly different than controls.

CONCLUSION AND CLINICAL IMPORTANCE

Symmetrical lupoid onychomadesis in bearded collies is clinically similar to what has been described in other breeds with regard to clinical signs and response to treatment. Early strenuous activity may increase the risk for disease occurrence in this breed.

Immunohistochemical Evaluation of Mononuclear Infiltrates in Canine Lupoid Onychodystrophy

Claw biopsy samples of 11 dogs with lupoid onychodystrophy were evaluated. They were stained with hematoxylin and eosin and with antibodies against CD 3 as a T-cell marker, BLA 36 and HM 57 (CD 79α) as B-cell markers, and lysozyme, Mac 387, and major histocompatibility complex (MHC) class II as a marker for histiocytes using an immunoperoxidase and avidin-biotin technique. Inflammatory cells were counted in five high-power fields. The inflammatory infiltrate comprised predominantly B cells and T cells. Macrophages were typically only present in small numbers. CD 3, BLA 36, lysozyme, and MHC class II preserved significant antigenicity during formalin fixation and short decalcification for 24–48 hours, whereas CD 79α and particularly Mac 387 seemed to be more susceptible to denaturation by the decalcification process.

A retrospective study regarding the treatment of lupoid onychodystrophy in 30 dogs and literature review

The treatment records of 30 dogs with lupoid onychodystrophy were evaluated retrospectively. Dogs were treated with fatty acid supplementation (n=18), doxycycline and niacinamide (n=12), tetracycline and niacinamide (n=10), pentoxifylline (n=6), prednisolone (n=5), azathioprine (n=1), clofazimine (n=1), or with combinations thereof. An excellent response was seen in almost half of the patients treated with tetra- or doxycycline in combination with niacinamide. Six of the dogs were maintained successfully on fatty acid supplementation. Spontaneous remissions and recurrences made evaluation of success rates difficult and emphasized the varied and often unclear etiology and natural course of the syndrome.

Canine symmetrical lupoid onychodystrophy: a retrospective study with particular reference to management

The records of six dogs in which a diagnosis of symmetrical lupoid onychodystrophy (SLO) had been made were examined retrospectively. The age at onset ranged from six months to eight years. All the dogs had been presented with onycholysis, onychomadesis, onychalgia and onychodystrophy. The diagnosis of SLO was confirmed in all cases by histological examination. Histological features were similar in all cases and included hydropic degeneration of the basal cell layer, pigmentary incontinence and a cell-rich interface dermatitis. Response (defined as good, partial or failure) to various therapies was compared. Treatments (as initial therapy or following previous treatment failure) included essential fatty acids (EFA) (three cases), a combination of tetracycline and nicotinamide (four cases) and azathioprine and/or prednisolone (one case each). EFA therapy resulted in one good response, one partial and one failure, tetracycline and nicotinamide in two good responses, one partial and one failure, and azathioprine and/or prednisolone in one good and one partial response. Although all treatments were successful in some cases, none was universally effective.

Diagnosis and management of canine claw diseases

The diagnostic workup for canine claw disease consists of a good history and complete clinical examination which may provide clues for a possible underlying disorder. In dogs with claw disease but no other clinical or historical signs, further recommended diagnostic procedures include cytological evaluation of impression smears or discharge from the claw fold, bacterial culture and sensitivity testing, biopsy of the claw matrix, and an elimination diet for 6 to 8 weeks. If no underlying disease can be identified, trial treatment with essential fatty acid supplementation, vitamin E, or a combination of doxycycline hydrochloride and niacinamide may be useful. In some patients, onychectomy of all claws may be considered.