Use of carbon dioxide laser for onychectomy in cats

OBJECTIVE: To compare postoperative signs of discomfort and complications associated with use of CO2 laser for onychectomy with those of the scalpel technique in cats. DESIGN: Prospective, randomized, masked clinical trial. ANIMALS: 20 client-owned cats. PROCEDURE: Forelimb feet (right, left) were randomly assigned to laser and scalpel treatment groups. Signs of discomfort (lameness and signs of pain) and complications (hemorrhage, swelling, and discharge) were assessed on days 0, 1, and 7. Surgeries were performed by 1 experienced surgeon. Evaluations were performed by 2 individuals without knowledge of treatment group. Signs of discomfort and complications were scored on scales of 0 to 8 and 0 to 9, respectively. RESULTS: Onychectomy did not result in high discomfort or complication scores 1 day after surgery, regardless of technique used, although the laser-treated group had significantly lower scores for signs of discomfort and complications. Seven days after surgery, significant differences were not detected between groups for signs of discomfort or complications. CONCLUSIONS AND CLINICAL RELEVANCE: The CO2 laser can be an excellent tool for onychectomy in cats, with excellent hemostasis and minimal postoperative discomfort and complications. Differences in discomfort and complications between groups treated via scalpel versus CO2 laser were not clinically relevant and were only observed 1 day after surgery.     

Use of lomustine to treat cutaneous nonepitheliotropic lymphoma in a cat

A 17-year-old spayed female domestic shorthair cat was referred for evaluation of severe skin lesions, including ulceration, nodule formation, erythema, and alopecia. Cutaneous nonepitheliotropic lymphoma was diagnosed histologically. There was no evidence of visceral organ involvement, but renal function was decreased. The cat was treated with lomustine (45.5 mg/m2, PO, q 21 d), and skin lesions resolved after administration of the third dose. No severe toxicoses were identified. Results suggest that lomustine may be useful for treatment of cutaneous nonepitheliotropic lymphoma in cats; however, optimal dosage, efficacy, and potential adverse effects must be determined.     

Use of bisphosphonates to treat severe idiopathic hypercalcaemia in a young Ragdoll cat

A 3-year-old Ragdoll cat was referred for investigation of polyuria, polydipsia, vomiting, weight loss and hypercalcaemia. Serum biochemical abnormalities included total and ionised hypercalcaemia and hypophosphataemia. Following clinical investigations a diagnosis of idiopathic hypercalcaemia was made. Because of the severity of the hypercalcaemia and the associated clinical signs, treatment for hypercalcaemia was commenced with pamidronate. Major electrolyte abnormalities were detected but, remarkably, were accompanied by minimal clinical signs. The cat was subsequently treated with oral alendronate and is clinically normal 15 months later. Reports of the use of bisphosphonates in cats are limited and close monitoring of patients is recommended.     

The use of carbon dioxide laser for the ablation of meibomian gland adenomas in dogs

Twelve eyelid meibomian gland adenomas in dogs were surgically ablated using the carbon dioxide (CO(2)) laser. The laser site was not sutured. All procedures resulted in complete removal of the adenoma with no recurrences at 6 months. In addition, no dogs developed corneal disease secondary to the procedure, and the cosmetic appearance of the eyelid margins was good at the end of the 6-month study. Based on results of this study, CO(2) laser ablation of canine meibomian gland adenomas is an effective alternative to standard surgical removal.     

Use of chemical ablation with trichloroacetic acid to treat eyelid apocrine hidrocystomas in a cat

CASE DESCRIPTION: A 7-year-old Persian cat was evaluated for recurrence of multiple cystic periocular masses. A number of cyst-like lesions had been resected from the left eyelids 18 months earlier, with lesions recurring within 6 months after surgery. The cat had blepharospasm and signs of discomfort following rupture of the largest cyst the day prior to examination. Previous histologic examination of the cysts had revealed apocrine hidrocystomas. CLINICAL FINDINGS: Multiple pigmented nodules were seen around the skin of the upper and lower left eyelids. The nodules were brownish to black, round, soft, and fluid-filled. Signs of pain were not evident during palpation of the nodules. TREATMENT AND OUTCOME: The largest cyst on the upper eyelid was removed by means of a V-shaped full-thickness excision. Histologic and immunohistochemical examination of the excised tissue confirmed the diagnosis of apocrine hidrocystoma. The remaining periocular cysts were surgically debrided and then treated topically with 20% trichloroacetic acid. All lesions healed rapidly without any signs of discomfort. During a recheck examination 12 months later, the upper and lower left eyelids appeared morphologically normal, and there was no evidence of recurrence. CLINICAL RELEVANCE: Findings suggested that chemical ablation with trichloroacetic acid may be a useful treatment for apocrine hidrocystomas in cats.     

Use of the carbon dioxide laser for perianal and rectal surgery.

The skin of the perianal region is very thin and sensitive. The carbon dioxide laser is a very effective tool for removing tumors and treating conditions of this area. It offers a "no touch" method of treatment for conditions of the perianal region. There is less bleeding, less pain, less swelling with the use of the carbon dioxide laser. The carbon dioxide laser is an effective tool for excising perianal tumors, rectal tumors, performing anal sacculectomies and treating perianal fistulas.     

犬外耳道耵聍腺腺瘤的病理学诊断

通过临床观察、组织学诊断结合免疫组织化学染色对一例犬外耳道肿瘤进行病理学诊断。本病例为13岁雄性苏格兰牧羊犬,肿瘤发生于左侧外耳道,眼观肿物呈灰白色,形成乳头状结节,与周围组织界限清晰。组织学观察可见结缔组织将实质分成小的囊状结构;实质细胞增生,呈典型的顶浆分泌性腺体结构,核大而圆,异型性小,形成乳头状突起;间质中有多量的血管,并伴有炎性细胞浸润。免疫组织化学中的CK染色发现增生的实质细胞为上皮细胞,而通过SMA染色可见腺上皮被覆一层完整的肌上皮细胞。通过以上诊断方法确定该犬患为外耳道耵聍腺腺瘤。     

Use of laser rhinoscopy to treat a nasal obstruction in a captive California sea lion (Zalophus californianus).

Laser rhinoscopy was used to treat a nasal obstruction in a captive California sea lion (Zalophus californianus). The rehabilitated, adult, female sea lion developed mucopurulent, intermittent, bilateral nasal discharge and functional nasal obstruction 20 mo after acquisition by the Aquarium of the Pacific in Long Beach, California. A 3-mm-thick soft tissue structure spanning the region between the soft and hard palates, a deviated nasal septum, and several nasopharyngeal polyps were identified. Biopsies and cultures of the obstructive web showed ulcerative granulation tissue with suppurative inflammation, bacterial infection, and a partial section of an arthropod larva (not speciated). Laser rhinoscopy was performed to relieve the caudal nasopharyngeal obstruction and ablate the polyps. The sea lion appeared to breathe through the nares with lessened nasal discharge for a period of 6 wk after laser therapy, but within 8 wk the mucopurulent nasal discharge returned, the obstruction had reformed, and the sea lion was euthanized. Postmortem examination confirmed antemortem diagnoses of caudal nasopharyngeal obstruction secondary to inflammatory tissue; however, no additional sections of arthropod parasites were located microscopically.     

Use of end-tidal partial pressure of carbon dioxide to predict arterial partial pressure of carbon dioxide in harp seals during isoflurane-induced anesthesia

OBJECTIVE: To evaluate the relationship between end-tidal partial pressure of CO(2) (ETCO(2)) and PaCO(2) in isoflurane-anesthetized harp seals. ANIMALS: Three 5-month-old 25- to 47-kg harp seals (Phoca groenlandica). PROCEDURES: PaCO(2) was determined in serial arterial samples from isoflurane-anesthetized seals and compared with concomitant ETCO(2) measured with a side-stream microstream capnograph. Twenty-four paired samples were subjected to linear regression analysis and the Bland-Altman method for assessment of clinical suitability of the 2 methods (ie, PaCO(2) and ETCO(2) determinations). The influence of ventilation rate per minute (VR) on the ETCO(2) to PaCO(2) difference (P[ET-a] CO(2)) was examined graphically. RESULTS: The correlation coefficient between the 2 measurements was 0.94. The level of agreement between ETCO(2) and PaCO(2) varied considerably. Values of ETCO(2) obtained with a VR of < 5 underestimated PaCO(2) to a greater degree (mean bias, -4.01 mm Hg) and had wider limits of agreement of -13.10 to 5.07 mm Hg (-4.01 mm Hg +/- 1.96 SD), compared with a VR of > or = 5 (mean bias, -2.24 mm Hg; limits of agreement, -7.79 to 3.30 mm Hg). CONCLUSIONS AND CLINICAL RELEVANCE: These results indicate that a microstream sidestream capnograph provides a noninvasive, sufficiently accurate estimation of PaCO(2) with intermittent positive ventilation at a VR > or = 5 in anesthetized harp seals.     

Anal sac gland carcinoma in a cat

A perianal mass in a 15-year-old domestic shorthair cat with a history of a firm, painful swelling in the left ventrolateral perianal region was surgically excised and submitted for light microscopic evaluation. Histologically, this was a poorly demarcated, unencapsulated, multilobulated neoplasm that invaded surrounding perirectal skeletal muscle bundles. Lobules were composed of sheets and acinar arrangements of cuboidal to round neoplastic epithelial cells with scant to moderate eosinophilic to amphophilic cytoplasm and a round or oval nucleus with coarse chromatin. Mitotic figures were 2 per 40 x objective field. Acinar lumina sometimes contained eosinophilic proteinaceous material or cell debris. These microscopic features are consistent with anal sac gland carcinoma. This is the second report of this neoplasm in a cat.     

Congenital adrenal hyperplasia secondary to 11beta-hydroxylase deficiency in a domestic cat

A calico-colored domestic shorthair cat was examined because of possible cryptorchidism. The cat had a fully formed penis, prepuce, and scrotum, but no descended testes, and exploratory laparotomy revealed a grossly normal female internal genital tract (ie, 2 ovaries, 2 uterine horns, and uterine body). Chromosomal analysis revealed a normal female (38,XX) karyotype. Four months later, the cat was examined because of polyuria, polydipsia, and inappropriate urination. Serum cortisol and aldosterone concentrations were low, and results of an ACTH stimulation test were suggestive of decreased adrenal gland function. Serum ACTH, testosterone, androstenedione, progesterone, 17-hydroxyprogesterone, 11-deoxycortisol, and deoxycorticosterone concentrations were high, and a diagnosis of congenital adrenal hyperplasia secondary to 11beta-hydroxylase deficiency was made. Treatment with prednisone diminished clinical signs but had a variable effect on corticosteroids hormone concentrations. To the author's knowledge, this is the first report of congenital adrenal hyperplasia in a cat.     

Use of a carbon dioxide laser for surgical management of cutaneous masses in horses: 32 cases (1993-2000)

OBJECTIVE: To determine outcome of horses in which cutaneous masses were removed with a carbon dioxide laser. DESIGN: Retrospective study. ANIMALS: 32 horses. PROCEDURE: Medical records of horses with 1 or more cutaneous masses treated with a carbon dioxide laser were examined. Follow-up information was obtained through telephone interviews with owners and referring veterinarians. RESULTS: Cutaneous masses were classified as sarcoids (15 horses), neoplastic masses other than sarcoids (squamous cell carcinoma [91; fibroma [1]; and melanoma [1]), and nonneoplastic masses (6). Minimum follow-up time was 6 months. Five sarcoids and 2 squamous cell carcinomas recurred. Seven (21%) horses had complications associated with dehiscence of wounds that had been closed primarily or failure of wound healing because of recurrence of the mass. Twenty-six (81%) owners were satisfied with the cosmetic appearance following surgery. CONCLUSION AND CLINICAL RELEVANCE: Results suggest that a carbon dioxide laser may be effective for treatment of cutaneous masses in horses.     

Use of CO2 laser as an adjunctive treatment for caudal stomatitis in a cat

Lasers have become a popular tool in veterinary practice, particularly the carbon dioxide (CO2) laser. In humans, the CO2 laser is used most commonly in oral and maxillofacial soft tissue surgery due to its favorable interactions with oral soft tissues. Other types of lasers are better suited for use on hard tissues such as enamel and dentin. This article reviews the history of laser use, physics of laser-tissue interaction, delivery systems, and laser types used in dentistry and oral surgery. This is followed by a case report describing the use of CO2 laser as an adjunctive treatment for therapy of refractory caudal stomatitis in a cat.     

Treatment of common cutaneous tumors using the carbon dioxide laser

Treatment of common cutaneous neoplasms in the horse, including equine sarcoid, squamous cell carcinoma, and melanoma, can be problematic. Over the years, many techniques have been developed to minimize recurrence associated with the removal of these neoplasms. Lasers may be used to remove cutaneous tumors, offering the advantage of thermal coagulation of the surgical margins. The thermal effect may help to eliminate abnormal cells left behind by conventional surgical techniques. Combining laser surgery with adjunctive therapy, including intralesional, topical, or systemic chemotherapy or immunotherapy, provides additional protection.     

Mammary fibroadenomatous hyperplasia in a young cat attributed to treatment with megestrol acetate

A male, neutered cat was presented for lethargy, reluctance to walk, and mammary enlargement after recent treatment with megestrol acetate. Mammary fibroadenomatous hyperplasia was diagnosed on the basis of history, clinical signs, and histopathological findings. Pathogenesis, clinical signs, and treatment options for mammary fibroadenomatous hyperplasia attributed to megestrol acetate treatment are discussed.     

Oncocytoma in the mandibular salivary gland of a cat

A cat was referred for investigation of a soft tissue mass caudal to the left mandible. Initial investigations suggested a malignant salivary gland tumour, and the mass was removed by extracapsular resection of the mandibular gland. Histopathology showed an oncocytoma within the salivary gland. An oncocytoma is a neoplastic transformation of oncocytes. Oncocytes are cells with a small nucleus and intense eosinophilic granular cytoplasm due to numerous mitochondria, which proliferate during ageing in exocrine and endocrine glandular tissues. Physiological proliferation occurs next to oncocytosis, oncocytoma, and oncocytic carcinoma. This is the first report of an oncocytoma in a feline mandibular salivary gland, and the first report of long-term survival after surgical removal.