We compared clinical characteristics and outcomes for dogs with various digital tumors. Medical records and histology specimens of affected dogs from 9 veterinary institutions were reviewed. Risk factors examined included age, weight, sex, tumor site (hindlimb or forelimb), local tumor (T) stage, metastases, tumor type, and treatment modality. The Kaplan-Meier product limit method was used to determine the effect of postulated risk factors on local disease-free interval (LDFI), metastasis-free interval (MFI), and survival time (ST). Outcomes were thought to differ significantly between groups when P < or = .003. Sixty-four dogs were included. Squamous cell carcinoma (SCC) accounted for 33 (51.6%) of the tumors. Three dogs presented with or developed multiple digital SCC. Other diagnoses included malignant melanoma (MM) (n = 10; 15.6%), osteosarcoma (OSA) (n = 4; 6.3%), hemangiopericytoma (n = 3; 4.7%), benign soft tissue tumors (n = 5; 7.8%), and malignant soft tissue tumors (n = 9; 14%). Fourteen dogs with malignancies had black hair coats, including 5 of the 10 dogs with MM. Surgery was the most common treatment and, regardless of the procedure, had a positive impact on survival. None of the patient variables assessed, including age, sex, tumor type, site, and stage, had a significant impact on ST. Both LDFI and MFI were negatively affected by higher T stage, but not by type of malignancy. Although metastasis at diagnosis correlated with a shorter LDFI, it did not have a significant impact on ST. On the basis of these findings, early surgical intervention is advised for the treatment of dogs with digital tumors, regardless of tumor type or the presence of metastatic disease.

Purpose: The immunotoxin BR96 sFv-PE40 is an effective antitumor agent against human breast and lung carcinoma xenografts in rodents. This study was designed to (a) determine the frequency with which canine carcinoma cells express Lewisy (Ley) antigen, thereby identifying canine carcinoma types suitable for the clinical evaluation of BR96 sFv-PE40, and (b) determine the safety and efficacy of BR96 sFv-PE40 in a canine model of spontaneously occurring cancers for investigation of targeted therapy. Experimental Design: Carcinoma tissue samples were obtained from client-owned dogs presented for medical care. The tissues were assessed for Ley antigen expression using immunohistochemical methods. Dogs with tumors expressing Ley antigen were offered enrollment in a clinical trial to receive twice-weekly infusions of 4 to 12 mg/m2 BR96 sFv-PE40. Clinical toxicity and response data were assessed at each treatment. Results: Twenty-two of 61 carcinomas evaluated were positive for Ley expression, including mammary, prostate, lung, and rectal carcinomas, and 12 dogs were enrolled in the clinical trial. The primary side effect was transient emesis. Partial responses or disease stabilization were noted in dogs with inflammatory mammary, bronchogenic, rectal, and tonsillar carcinoma. At least nine of the dogs developed antibodies to the immunotoxin after two to five infusions. Conclusions: Although development of anti-BR96 sFv-PE40 antibodies limited the long-term effectiveness of this immunotoxin in dogs, rapid clinical responses in several aggressive canine carcinomas suggest the immunotoxin has utility for treatment of certain naturally occurring tumors and that its clinical evaluation for treatment of similar human carcinomas is warranted.

Research has indicated that results of blood tests for retired greyhounds may fall outside the established normal ranges for the general canine copulation and that specific parameters for retired greyhounds may need to be established. Based on the study discussed in this article, the authors determined that hemoglobin, creatinine, sodium, total carbon dioxide, and anion gap tend to be elevated whereas globulin tends to be decreased in healthy retired greyhounds. Practitioners need to be aware of these breed-specific differences in order to make accurate diagnoses in greyhounds.

Previous studies examining the radiosensitizing effects of perfluorochemical emulsions have based dose recommendations on a measurement known as fluorocrit. The fluorocrit is the proportion of blood volume occupied by perfluorochemicals and is measured using standard hematocrit procedures. This measurement is inherently crude and subject to error and variability between different individuals measuring the same sample. Furthermore, the fluorocrit method has not been compared to other quantitative methods to determine its reliability. The purpose of this study was to compare fluorocrit measurements to those obtained by gas chromatographic analysis. A 90% w/v perflubron emulsion was administered to six normal dogs once weekly for four weeks and peripheral blood samples were obtained at specified time points for analysis. A total of 123 blood samples were analyzed by both methods. The relationship between blood fluorocrit and plasma perflubron concentration measured by gas chromatography was examined using regression models. Based on the modest predictive value (r(2) = 0.3683) of the derived statistical model, we conclude that fluorocrit measurement is an inaccurate method of estimation of blood perflubron concentration. Caution must, therefore, be exercised when extrapolating data and dose recommendations from reports of studies using fluorocrit as the only estimate of blood perflubron concentration.

Case records of 64 dogs with nasal adenocarcinoma were reviewed. The effects of age, gender, tumor stage, presence of metastatic lesions, and treatment method on survival time were examined. Surgery groups included rhinotomy (n = 9), transnasal curettage (n = 29), and no surgery (n = 26). Chemotherapy groups included fluorouracil-cyclophosphamide combination therapy (n = 15), mitoxantrone (n = 7), and no chemotherapy (n = 42). Fifty-three dogs received fractionated cobalt 60 radiation therapy. Surgical procedure, chemotherapy group, and stage of primary tumor were not significantly associated with survival time (P > .05). Dogs that received radiation therapy had a significantly longer median survival time (424 days) than dogs that did not (126 days)(P = .0001). The presence of either regional lymph node or pulmonary metastasis was associated with significantly shorter median survival time (109 days) when compared to dogs without metastases (393 days)(P = .0125). When only dogs that had received radiation therapy were considered, neither surgical treatment nor chemotherapy group was associated with significant changes in median survival time. An alternate staging system emphasizing the presence or absence of metastases is proposed.

OBJECTIVE:To characterize the frequency, clinical signs, biologic behavior, and response to treatment of tumors of the ear canal in dogs and cats.DESIGN:Retrospective analysis of medical records.ANIMALS:Medical records of 81 dogs (48 malignant tumors, 33 benign tumors) and 64 cats (56 malignant tumors, 8 benign tumors).PROCEDURE:Data were analyzed for cats and dogs with malignant tumors, and risk factors were analyzed for their potential impact on survival time.RESULTS:Malignant tumor types most commonly reported included ceruminous gland adenocarcinoma, squamous cell carcinoma, and carcinoma of undetermined origin. Median survival time of dogs with malignant aural tumors was > 58 months, whereas that of cats was 11.7 months. A poor prognosis was indicated by extensive tumor involvement (dogs) and by neurologic signs at time of diagnosis, diagnosis of squamous cell carcinoma or carcinoma of undetermined origin, and invasion into lymphatics or blood vessels (cats).CLINICAL IMPLICATIONS:Malignant tumors of the ear canal in dogs and cats have a propensity for local invasion, but tend not to metastasize. Squamous cell carcinoma and carcinoma of undetermined origin were the most locally aggressive tumors. Malignant tumors of the ear canal are best managed by aggressive surgical excision. Radiotherapy may be useful when tumors cannot be completely removed.

Since the enactment of state laws requiring rabies vaccination in cats, there has been an increase in the number of sarcomas in cats. Rabies vaccine and FeLV vaccines are most commonly implicated in vaccination-site sarcomas. Routine rabies vaccination places cats at a higher risk for sarcomas. This risk may increase when multiple vaccines are given simultaneously at the same site. Current recommendations are to inject rabies vaccine on the caudal half of the right side and FeLV vaccine on the caudal half of the left side of the cat's body. The causes of the sarcomas are unknown; a link with vaccine adjuvant composition or high concentrations of antigen has been suggested. Although the benefits of vaccination should not be minimized, clients should be aware of the risk. Recommendations have been made to minimize the risk to feline patients and to better classify the occurrence of vaccination-site sarcomas. Diagnosis is based on documentation of injection sites and histopathologic diagnosis of a sarcoma. Treatment of vaccination-site sarcomas does not differ significantly from treatment of lesions that arise at nonvaccination sites and consists of surgical excision, radiation therapy, and chemotherapy. Clinicians and clients should be aware, however, that vaccination-site sarcomas tend to be more aggressive and have a higher rate of recurrence.

The hypothalamic-pituitary-adrenocortical (HPA) axis was studied in 8 healthy cats after administration of supraphysiologic doses of methylprednisolone (MP). Ovine corticotropin-releasing hormone (oCRH) administration increased cortisol and adrenocorticotropic hormone (ACTH) concentrations. Significant (P < 0.05) suppression of cortisol and a trend toward suppression of ACTH was observed after 1 week of MP administration. The HPA axis quickly recovered from suppressive effects of MP 1 week after administration of the steroid was discontinued. Side effects of oCRH administration were minimal in 7 cats; however, 1 cat had a severe hypotensive reaction. Clinical abnormalities were not associated with MP administration. The HPA axis was suppressed by supraphysiologic doses of MP in all treated cats that lacked clinical signs consistent with iatrogenic HPA axis suppression. Despite the relatively active pars intermedia in cats, compared with human beings and dogs, feedback of MP on the HPA axis resulted in similar trends in oCRH-stimulated ACTH and cortisol concentrations as observed in human beings and dogs. Lack of consistent correlation between ACTH and cortisol concentrations was observed in 3 cats and possibly was related to the active pars intermedia in the cat.

Two 6-month-old littermate Shetland Sheepdogs were found to have severe thymic hemorrhage,unassociated with trauma or poisoning. One dog survived the insult with supportive care, and the other died and was necropsied. Antemortem laboratory data and radiographic findings for both dogs were consistent with acute blood loss into the mediastinum. Hemorrhage was restricted to the thymus and mediastinum in both dogs.

This study determined the OXYGENT CA (90% w/v perflubron emulsion, Alliance Pharmaceutical Corporation) dose necessary to achieve a 3-4% fluorocrit, and the tolerance of this dose administered once per week for four weeks to dogs. This study simulated OXYGENT CA use as a radiosensitizing agent. Six adult dogs were administered 6 ml/kg OXYGENT CA once per week for 4 weeks. Blood samples were collected following infusion, until fluorocrits were < or = 0.5%. One week after the fourth infusion, three dogs were necropsied. Liver biopsies were obtained from the remaining three dogs which were monitored 12 additional weeks. All dogs achieved fluorocrits > 3.0% (3.5-5.1%) with the 6 ml/kg dose. A 3 ml/kg dose did not provide a fluorocrit > 3.0%. Serum bilirubin concentrations were elevated at 24-hour sampling times and declined within 72 hours. Elevations in ALT, SAP, and bile acids were noted. Splenic and hepatic microvasculature fibrosis occurred in the long-term study dogs. Thrombocytopenia occurred in 5/6 dogs, necessitating exclusions of one dog from 2 infusions. However, 3/5 thrombocytopenic dogs had titers for Ehrlichia sp., which elicits thrombocytopenia. Therefore, we cannot conclude the effect of OXYGENT CA on platelets.

The purpose of this study was to examine the feasibility of a combination chemotherapy protocol ("CYCLONE") in cats, utilizing mitoxantrone and cyclophosphamide. Three normal adult cats were administered mitoxantrone (6.5 mg/m2 intravenously) and cyclophosphamide (100 mg/m2 intravenously) every 21 days for a total of three doses. Individual white blood cell count nadirs (range, 2.0-9.5 x 10(9)/L) and neutrophil count nadirs (range, 0.3 to 5.0 x 10(9)/L) occurred between days 2 and 10 after each dose of chemotherapy. Mean white blood cell count nadirs (range of mean, 5.5 to 8.4 x 10(9)/L) occurred between days 6 and 8, as did the mean neutrophil count nadir (range of mean, 1.7-4.0 x 10(9)/L). Side effects were limited to transient appetite suppression in one cat and loose stools in two cats. Myelosuppression and gastrointestinal side effects were comparable to those observed with single-agent mitoxantrone protocols. Further investigation of this protocol is warranted.

Twenty-five dogs with naturally occurring mast cell tumors were treated with daily oral prednisone (1 mg/kg) for 28 days, Five dogs (20%) had reduction in tumor volume and were considered responders. Four of these underwent partial remission and one underwent complete remission, Survival times for the five responders were 3, 5, 6, 7.5, and greater than 28 months, respectively. We therefore conclude that prednisone is effective in some canine mast cell tumors. Further studies are indicated to determine the most effective dose of prednisone, the appropriate duration of treatment, and the efficacy in more benign mast cell tumors, and in combination with other forms of therapy.

Doxorubicin is reported to cause myelosuppression, with a white blood cell count nadir occurring between day 7 and day 10. Thrombocytopenia is less severe and occurs between days 3 and 8. This report presents an early onset of leukopenia (day 5) and a severe thrombocytopenia (4000 platelets/microliter) (day 6) associated with doxorubicin administration for treatment of recurrent tonsillar squamous cell carcinoma in a dog.

Knowledge of dermatologic and neoplastic diseases of domestic animals has rapidly expanded during the past ten years. Despite this growth, recognized cutaneous paraneoplastic diseases are few and uncommon. Several cutaneous diseases that are markers for neoplasms in humans occur in animals but they have not been associated with concurrent neoplasia. This article focuses on two veterinary cutaneous paraneoplastic syndromes, and briefly describes those cutaneous syndromes of animals that are paraneoplastic in humans.

Local current field radiofrequency hyperthermia was applied to 33 superficial tumors in 11 cats and 5 dogs. Squamous cell carcinoma (SCC) in the cat was the most frequent tumor treated. Of 19 SCC in cats, 13 (68%) were reduced completely, combining complete and partial tumor reduction, there was an 89% favorable response to hyperthermia for SCC. A small number of other tumors such as fibrosarcoma in the cat and perianal tumors in the dog were favorably responsive. Local current field hyperthermia (50 C for 30 sec) resulted in destruction of tumor tissue as well as normal tissue. However, tissue destruction did not extend more than 2 or 3 mm from the electrodes. Ulcerative superficial tumors exposed to air rapidly reduced in size, and a dry eschar that developed fell off at 17 to 25 days.

Forty-five ocular squamous cell carcinomas (SCC) in 17 cattle and 8 horses were treated by radiofrequency hyperthermia, resulting in 80% complete regression and 16% partial regression. Tumors were histologically diagnosed as SCC; 50% of the tumors were recurrent, having been treated previously by surgery, cryosurgery, radiation, or immunotherapy. After hyperthermic treatment, most animals were available for tumor measurement at 4 to 6 weeks and at 8 to 16 weeks, with a final observation period of 2 to 10 months for all. Complete regression occurred in 8 of 12 tumors given a second hyperthermic treatment. It was concluded that hyperthermia is an effective and easily applied treatment modality for ocular SCC in cattle and horses; however, it cannot be recommended for large tumors (larger than equal to 5 cm diameter) that have deep eyelid or conjunctival penetration.