Local current field radiofrequency hyperthermia for the treatment of superficial skin tumours in cats

Local current field radiofrequency (LCF-RF) hyperthermia was used to treat 38 superficial skin tumours (predominantly squamous cell carcinomas) of the nose, face and ears in 35 cats. LCF-RF hyperthermia was applied at 50°C for 60 seconds at single or multiple sites depending on the tumour size. Each cat was observed over a four-month period after treatment and 14 out of 35 cases were also available for re-evaluation eight months after treatment. Tumours which had not resolved completely within one month after the initial treatment were re-treated.

LCF-RF hyperthermia is most suited for the treatment of superficial skin tumours (<5 mm diameter). Ninety-two per cent (12/13) of tumours of this dimension showed some regression and 69% (9/13) completely resolved. Larger tumours >5 mm diameter) were also successfully treated. 54% (8/14) regressed but only 14% (2/14) completely resolved. LCF-RF hyperthermia is not recommmended for the treatment of tumours of the pinnae as 5 of the 6 tumours at this site failed to respond.     

Free skin grafting for treatment of distal limb skin defects in cats

The technique and results of free skin grafts have been described in dogs, horses, rabbits, goats and mice. The procedure in cats is, however, described only indirectly in papers relating to dogs. A standard technique has been developed by the authors for use in cats, and is reported for 17 grafts in 16 cats with traumatic injury to the legs resulting in large areas of skin loss. This paper describes the preparation of the wound for grafting, the harvesting of the graft, graft placement, postoperative care and the results of the application of this technique. The success rate in this series of cases was high. This was attributed to proper preparation of the recipient site, collection of the graft and postoperative bandaging. The results suggest that the success rate of free skin grafts in cats is considerably higher than that achieved by the present authors in dogs, and reported for dogs by other surgeons in the literature.     

Current concepts in the diagnosis and treatment of brain tumours in dogs and cats

Intracranial tumours occur relatively frequently in dogs, and less commonly in cats. With the availability of computed tomography (CT) and magnetic resonance imaging, more accurate determination of the location and extent of brain tumours in companion animals has become possible. Following these advances in imaging, precise CT-guided stereotactic techniques for both tumour biopsy and intratumoral drug delivery have been developed for use in cats and dogs. Also, tumour identification methods, such as crush preparation examination, have facilitated rapid tumour identification. The use of improved diagnostic techniques has resulted in an increasing demand for effective therapies for brain tumours. While surgical removal and irradiation remain important treatment considerations in the management of brain tumours of cats and dogs, the development of gene therapy strategies for treatment of intracranial tumours offers much promise, although research in this area is still at an early stage.     

Evaluation of trends in frequency of urethrostomy for treatment of urethral obstruction in cats

OBJECTIVE: To determine hospital proportional morbidity rates (HPMR) for urethral obstructions, urethral plugs or urethroliths, and urethrostomies in cats in veterinary teaching hospitals (VTH) in Canada and the United States between 1980 and 1999. DESIGN: Epidemiologic study. ANIMALS: 305,672 cats evaluated at VTH. PROCEDURES: Yearly HPMR were determined for cats with urethral obstructions, urethral plugs or urethroliths, or urethrostomies from data compiled by the Purdue Veterinary Medical Database. The test for a linear trend in proportions was used. RESULTS: Urethral obstructions were reported in 4,683 cats. Yearly HPMR for urethral obstructions declined from 19 cases/1,000 feline evaluations in 1980 to 7 cases/1,000 feline evaluations in 1999. Urethral plugs or urethroliths affected 1,460 cats. Yearly HPMR for urethral plugs or urethroliths decreased from 10 cases/1,000 feline evaluations in 1980 to 2 cases/1,000 feline evaluations in 1999. A total of 2,359 urethrostomies were performed. Yearly HPMR for urethrostomies decreased from 13 cases/1,000 feline evaluations in 1980 to 4 cases/1,000 feline evaluations in 1999. CONCLUSIONS AND CLINICAL RELEVANCE: Frequency of feline urethrostomies performed at VTH in Canada and the United States declined during the past 20 years and paralleled a similar decline in frequency of urethral obstructions and urethral plugs or urethroliths. These trends coincide with widespread use of diets to minimize struvite crystalluria in cats, which is important because struvite has consistently been the predominant mineral in feline urethral plugs during this period.     

Non-coherent light for photodynamic therapy of superficial tumours in animals

Cultured 9L cells were incubated with varying concentrations of pheophorbide‐a‐hexyl ether (HPPH) and then exposed to 665‐nm red light from a non‐coherent light source or a dye laser. Cell death was produced by both light sources, with the non‐coherent light being most effective at the highest HPPH concentrations. To assess the feasibility of using the non‐coherent light source for clinical photodynamic therapy (PDT), four dogs and three cats presenting with spontaneous superficial tumours were injected intravenously with 0.15 mg kg^?1 of HPPH, 1 h before their tumours were irradiated with 665‐nm non‐coherent light (50 mW cm^?2, 100 J cm^?2). Of the nine tumours treated, there were eight complete responses, all occurring in animals with squamous cell carcinoma. After 68 weeks of follow‐up, the median initial disease‐free interval had not been reached. These data suggest that non‐coherent light sources may be efficacious for photodynamic therapy of spontaneous superficial tumours in animals, representing a cost‐effective alternative to medical lasers in both veterinary and human oncology.     

Radiotherapy of pituitary tumours in five cats

Five cats tentatively diagnosed with pituitary adenoma (four cases) or pituitary carcinoma (one case), based on computed tomography (CT) or magnetic resonance imaging, were treated with radiotherapy. Electrons were applied in four cats and electrons and photons in the fifth. Ten to 12 fractions of 3.5 to 4.0 Gy each were delivered on a Monday/Wednesday/Friday schedule. The mean total dose applied was 39 Gy. No severe acute side effects to treatment were seen. Follow-up CT examination was performed in four cats; the mass had disappeared in one cat and remained stable or slightly decreased in size in the other three. The survival times were 5.5, 8.0, 15.0, 18.0 and 20.5 months, with two cats dying of causes unrelated to the tumour. Based on these cases, radiotherapy appears to be a valuable treatment option for feline pituitary tumours.     

Systemic treatment of bacterial skin infections of dogs and cats

Abstract Antibiotics and immunostimulants are used in the systemic treatment of bacterial skin infections in small animals. The major antibiotic groups commonly utilized are the macrolides, lincosamides, potentiated sulphonamides, β-lactamase-resistant penicillins, cephalosporins and fluoroquinolones. Empirical usage, culture and sensitivity, mode of action, dosages, efficacy and side-effects are reviewed. A summary of the veterinary literature relative to immunostimulants is also included. Résumé— Antibiotiques et immunostimulants sont utilisés dans le traitement systémique des infections bactériennes cutanées des animaux de compagnie. Les families d'antibiotiques les plus utilisées sont les macrolides, les lincosanides, les sulfonamides potentialisés, les pénicillines résistantes à la lactamase, les céphalosporines et les fluoroquinolones. L'utilisation empirique, l'isolement et l'antibiogramme, le mode d'action, les dosages, l'efficacité et les effets secondaires sont présentés. Un résumé de la littérature vétérinaire concernant les immunostimulants est également inclus. [White, S. D. Systemic treatment of bacterial skin infections of dogs and cats. (Traitement systémique des infections bactériennes cutanées du chien et du chat). Veterinary Dermatology 1996; 7 : 133–143.] Resumen Para el tratamiento sistémico de ls infecciones bacterianas cutáneas en pequeños animales se usan antibióticos e inmunoestimulantes. Los grupos de antibióticos más frecuentemente utilizados incluyen los macrólidos, lincosamidas, sulfonamidas potenciadas, penicilinas beta-lactamasa resistentes, cefalosporinas y fluoroquinolonas. Se revisan su uso empirico, cultivo y sensibilidad, mecanismo de acción, dosis, eficacia y efectos colaterales. Se incluye un resumen de la literatura veterinaria sobre immunoestimulantes. [White, S. D. Systemic treatment of bacterial skin infections of dogs and cats. (Tratamiento sistemico de las infecciones bacterianas cutaneas de perros y gatos). Veterinary Dermatology 1996; 7 : 133–143.] Zusammenfassung— Antibiotika und Immunstimulantien werden in der systemischen Behandlung von bakteriellen Hautinfektionen bei Kleintieren eingesetzt. Die Hauptgruppen der gewöhnlich verwendeten Antibiotika sind Markrolide, Lincosamide, potenzierte Sulfonamide, beta-Laktamase-resistente Penicilline, Cephalosporine und Fluroquinolone. Die empirische Anwendung, Kultur und Empfindlichkeit, Wirkungsweise, Dosierung, Wirksamkeit und Nebenwirkungen werden dargestellt. Eine Zusammenfassung der Veterinärliteratur bezüglich Immunstimulantien wird miteingeschlossen. [White, S.D. Systemic treatment of bacterial skin infections of dogs and cats (Systemische Behandlung von bakteriellen Hautinfektionen bei Hund und Katze). Veterinary Dermatology 1996; 7 : 133–143.]     

The management of oral tumours in dogs and cats

Successful management of oral tumours must achieve the dual needs of continued oral function and total destruction of often massive tumours. The most effective treatments currently available are radiation therapy and radical surgical excision involving partial mandibulectomy or maxillectomy, but the size of a tumour, its location, biological behaviour and the availability of treatment facilities will influence the mode of therapy chosen.     

Clinical study of cryosurgery efficacy in the treatment of skin and subcutaneous tumors in dogs and cats

Objective— To evaluate the efficacy of cryosurgery for treatment of skin and subcutaneous tumors in dogs and cats.
Study Design— Prospective study.
Animals— Dogs (n=20), cats (10).
Methods— Cutaneous or subcutaneous tumors were treated by liquid nitrogen cryosurgical spray (1 cm from target tissue at 90° until a 5-mm halo of frozen tissue was achieved) for 15–60 seconds. Malignant lesions had 3 freeze–thaw cycles benign tumors, 2 cycles. The second or third freeze cycle was performed after complete thaw of the preceding freeze. Wounds healed by second intention. Follow-up was weekly for 1 month and then twice monthly until wounds healed, and final outcome was determined by telephone interview of owners.
Results— Tumor size ranged from 0.3 to 11 cm diameter with 28 (60%) being 0.3–1 cm; 8 (17%) 1.1–3 cm, and 11 (23%) >3.4 cm. Complications included edema, erythema and for extremity lesions, pain and lameness. Treated lesions (n=47) had an overall remission of 98% (mean follow-up, 345±172.02 days [range, 150–750 days]). One malignant peripheral nerve sheath tumor recurred 7 months after cryosurgical treatment.
Conclusion— Cryosurgery is an efficient method for treatment of skin and subcutaneous tumors in dogs and cats.
Clinical Relevance— Cryosurgical ablation is an effective means of treating small cutaneous or subcutaneous tumors in dogs and cats, especially in older animals where wound closure or cosmetic outcome might limit surgical excision alone.     

Modification of the superficial cervical axial pattern skin flap for oral reconstruction

OBJECTIVE: To describe an extended pedicle flap based on the superficial cervical artery (SCA) for closure of oral defects in dogs. STUDY DESIGN: Anatomic study; in vivo experimental study. ANIMALS: Canine cadavers (13) and 3 dogs. METHODS: The prescapular branch of the SCA was cannulated and perfused with a lead oxide gelatin mixture. The area perfused by 1 SCA was examined as was the rostral extent of the flap. Staged implantation was performed to evaluate flap performance in vivo. In stage 1, the flap was prepared for implantation into the oral cavity. In stage 2, the flap was fully developed to include the 1 degrees, 2 degrees, and partial 3 degrees angiosome of 1 SCA pedicle. The flap was transposed by a bridging incision and a parapharyngeal tunnel into the oral cavity. The flap was used to reconstruct a partial-thickness defect created in the palate. RESULTS: The territory of the contralateral SCA was captured in all cadavers. The full flap reached the level of the canine teeth in all cadavers. In live dogs, necrosis was not observed after implantation into partial-thickness defects and dehiscence was minimal. Loss of pliability secondary to de-epithelialization and staging resulted in a limitation of rostral reach of the flap. CONCLUSIONS: Whereas the flaps did not reach as far rostrally as anticipated, they survived well in the harsh oral environment. The flap may be modified to reconstruct full-thickness palatal defects. CLINICAL RELEVANCE: The extended SCA pattern flap may be adapted for closure of oral defects.     

Radiotherapy for the treatment of periocular tumours in the horse

Periocular tumours are a relatively common problem in the horse, and present some unique challenges. Radiotherapy has long been considered the ‘gold standard’ for the treatment of periocular tumours in the horse, and there are various techniques of delivering this treatment. Although teletherapy and plesiotherapy are occasionally used, the most commonly used technique is interstitial brachytherapy. Low-dose rate interstitial brachytherapy has reported success rates of between 74 and 100% for the treatment of periocular sarcoids, and other tumours can also be successfully treated using this technique. There are significant disadvantages to the low-dose rate brachytherapy approach, and recently, a technique using high-dose rate brachytherapy has been described with a reported success rate of 100% for periocular sarcoid treatment. Electronic brachytherapy is a technique which may provide an alternative to high-dose rate brachytherapy, but its use for the treatment of periocular tumours has not been reported, and the requirement for general anaesthesia is a significant disadvantage.     

Glomus tumours in the skin and subcutis of three horses

Three horses presented with variably painful, nonulcerated masses of the head or neck that were diagnosed as glomus tumours. Grossly, they were fleshy, pink to tan masses ranging from 0.4 to 9 cm in diameter, involving either the deep dermis and subcutis or the subcutis and underlying skeletal muscle. Microscopically, neoplastic epithelioid cells were arranged in sheets, cords and packets within lobules. The neoplastic cells frequently abutted and formed nodular bulges into large endothelium-lined vascular spaces, especially around the tumour periphery. Large nerve branches were associated with each tumour. As determined by immunohistochemistry, the neoplastic cells consistently expressed α-smooth muscle actin and vimentin, and some cells in two of the cases expressed desmin. A laminin- or collagen IV-positive basement membrane was demonstrated around individual tumour cells or small groups of cells in all three cases. Morphological features and immunohistochemistry supported the diagnosis of glomus tumour, most consistent with the solid type in humans. Applying a classification system used in humans, two of these tumours met criteria of malignancy (glomangiosarcomas). One horse was euthanized due to complications associated with recurrence and treatment-related necrosis and secondary infection.     

Radiation therapy for long-term control of odontogenic tumours and epulis in three cats.

Orthovoltage radiation was used to treat odontogenic tumours in three cats following incomplete surgical resection. Cats received a total radiation dose of 48-52 Gy over a period of 26-29 days. Acute toxicities were mild, consisting of hair loss within the radiation field in all cats, and mild mucositis in one cat. All cats had long-term (>35 months) control of their tumour, and two cats are still alive without recurrence of tumour 60 and 39 months, respectively, after completing treatment. Radiation therapy should be considered to be an adjuvant to incomplete surgery in cats with odontogenic neoplasms or epulides.     

Ketoconazole for treatment of dermatophytosis in cats.

Twelve cats with generalized dermatophytosis were treated with ketoconazole (10 mg/kg of body weight, PO, with food, q 24 h). This treatment was successful in 8 cats, with resolution of lesions and negative findings on mycologic evaluation after 2 to 10 weeks (median duration, 6 weeks). One additional cat failed to improve initially, but complete resolution was achieved after the dosage of ketoconazole was doubled. Adverse effects in 3 cats included anorexia, weight loss, vomiting, and diarrhea.     

Clinical management of tumours in geriatric dogs and cats: systemic effects of tumours and paraneoplastic syndromes

There are many clinical presentations of neoplastic disease in the dog and cat. Some relate to the presence of a solid mass but many relate to the systemic effect that the tumour has on the animal. This paper covers the broad categories of the systemic metabolic and haematological effects that are associated with tumours in the dog and cat.     

The properties and use of penicillins in the veterinary field, with special reference to skin infections in dogs and cats

The use of the penicillins in veterinary dermatology is discussed. An outline is provided of the main penicillins used in the veterinary field. These include benzyl penicillin, penicillin V, ampicillin, amoxycillin, co-amoxiclav and oxacillin. An increase in β-lactamase production among strains of Staphylococcus intermedius , the principal canine pathogen in pyoderma, has been seen in recent years. Thus only those penicillins with resistance to β-lactamase (co-amoxiclav or isoxazolyl penicillins) are likely to be of value in treating canine pyoderma. However, feline, porcine and equine staphylococcal dermatoses, and other veterinary dermatoses such as the actinomycoses, dermatophilosis and erysipelothrix, usually respond well to most penicillins, whether or not they resist β-lactamase.