In vitro comparison of the dermal penetration of three different topical formulations containing lasalocid.

BACKGROUND: Topical antimicrobial preparations are of utmost importance in treating suspected and confirmed meticillin-resistant Staphylococcus pseudintermedius (MRSP) infections due to the increasing incidence of widespread resistance to systemic antimicrobials. Lasalocid is active against MRSP in vitro and this may become an important topical antimicrobial for the treatment of canine pyoderma. HYPOTHESIS/OBJECTIVES: To determine effects of various formulation types on penetration and retention of lasalocid applied to canine skin in vitro. ANIMALS: Normal canine skin was collected from the thorax of five dogs that had been euthanized on the basis of health and/or intractable behavioural issues. METHODS: Solution, lotion and ointment containing 2% lasalocid were applied to ex vivo canine skin. Transdermal penetration was assessed for a 24 h period and retention of lasalocid was assessed at the conclusion of the study. RESULTS: The solution had significantly higher skin retention of lasalocid and proportion of applied dose retained in skin than lotion and ointment (Tukey-Kramer Honest Significant Difference test, P < 0.01). Lasalocid could not be detected in the receptor fluid of any Franz cell at any time point. CONCLUSIONS AND CLINICAL IMPORTANCE: Lasalocid was not identified in the receptor fluid of any sample, indicating that systemic absorption of the active ingredient in vivo is unlikely. Lasalocid may be useful in the treatment of MRSP infections if in vivo studies support safety and efficacy.

Canine eosinophilic granuloma of the digits treated with prednisolone and chlorambucil.

BACKGROUND: Canine eosinophilic granuloma (CEG) is an uncommon disease. Lesions are typically located in the oral cavity and other cutaneous sites, but are rarely reported to affect the digits. The majority of cases are treated with prednisolone as a monotherapy; alternative treatment options include corticosteroids administered in combination with azathioprine, antihistamines, electrochemotherapy with bleomycin, and surgical resection. Neither chlorambucil nor laser previously have been reported as treatments. OBJECTIVES: To describe an alternative therapy for treatment of CEG; using chlorambucil in combination with prednisolone for those cases that fail to respond to prednisolone alone. The new treatment was chosen according to good clinical practice and after owner consent. ANIMALS: Two client owned dogs. METHODS: One case was initially treated with carbon dioxide laser to debulk the lesions. Both cases were treated with a combination of oral prednisolone and chlorambucil. RESULTS: Both dogs experienced rapid resolution of lesions with prednisolone and chlorambucil therapy. Case 1 remained in remission three months after withdrawing medication. Case 2 experienced relapse 10 weeks after discontinuing therapy but was well controlled on maintenance prednisolone with chlorambucil at low, well tolerated doses. CONCLUSIONS AND CLINICAL IMPORTANCE: Although CEG appears to be an uncommon disease, it should be included as a differential diagnosis for dermal, nodular lesions affecting the digits. Chlorambucil appears to be an effective and well tolerated prednisolone sparing agent for treatment of CEG. Carbon dioxide laser ablation appears to be an effective method of debulking CEGs.

Carbon dioxide laser treatment of extensive pigmented viral plaque lesions in a golden retriever dog.

BACKGROUND: Canine pigmented viral plaque (PVP) is an uncommon skin disease, associated with papillomavirus infection. Lesions are usually small (<1 cm diameter), pigmented macules to plaques on the ventral abdomen and medial thigh. ANIMALS: An 8-year-old male, neutered golden retriever dog presented with numerous dark plaques forming cohesive plaques on the ventrum extending down the medial aspect of both hind legs. The plaques were associated with significant pruritus. RESULTS: Histology confirmed a diagnosis of PVP and PCR amplified Canis familiaris papillomavirus 4 from a formalin fixed plaque sample. The PVPs were completely resolved by two courses of CO2 laser treatment. There was very minimal postoperative discomfort and no relapse or new lesion development within a 12 months follow-up period. CONCLUSIONS AND CLINICAL IMPORTANCE: Extensive PVPs have not previously been described in a golden retriever dog or previously reported to cause pruritus in dogs. Due to the large skin area involved, surgical excision was not feasible in this case. However, two rounds of treatment using laser were completely curative for both focal pedunculated and plaque-like PVP lesions. Additionally, compared to surgical excision, laser treatment is expected to result in less postoperative discomfort, reduced surgery time and fewer postoperative infections. This is the first report of successful treatment of canine PVPs using a CO2 laser. The success of this treatment in this case suggests that laser provides an excellent treatment option for extensive PVPs in dogs.