Results suggest that excision followed by electron beam irradiation may be beneficial for treatment of cats with vaccine-associated sarcomas. Extent of excision prior to radiotherapy did not seem to be associated with recurrence rate.

For most species of birds, ornamental plumage coloration may result from two types of pigments: carotenoids and melanins. Despite the fact that melanin pigments can be synthesized by birds from basic, amino acid precursors, while carotenoids cannot be synthesized by birds and must be ingested, melanin-based plumage coloration and carotenoid-based plumage coloration have often been treated as a single trait in investigations of the function and evolution of plumage coloration. Expression of carotenoid-based coloration is known to be dependent on condition, while the e¡ects of individual condition have not been welltested for expression of melanin-based coloration. In this study, we experimentally tested the e¡ect of coccidial infection of the intestinal tract of male house ¢nches during moult on expression of melaninbased plumage coloration. Coccidial infection had a signi¢cant negative e¡ect on carotenoid-based coloration, but it had no signi¢cant e¡ect on melanin-based feather coloration. Unlike carotenoid-based coloration, melanin-based coloration my be cheap to produce, and honesty of melanin-based coloration may require social mediation.

No abstract

Carotenoid pigments produce the ornamental red, orange, and yellow integumentary coloration of many species of animals. Among individuals of a population, the hue and saturation of carotenoid-based ornaments can be extremely variable, and studies of fish and birds have shown that females generally prefer males that display the most saturated and reddest coloration. Consequently, there has been a great deal of interest in determining the proximate factors that affect individual expression of carotenoid-based pigmentation. Parasites might affect production of ornamental coloration, and the Hamilton-Zuk hypothesis proposes that parasitized males will show decreased expression of the secondary sexual traits preferred by females. We found that captive male House Finches (Carpodacus mexicanus) experimentally infected with Isospora spp. (coccidians) and/or Mycoplasma gallisepticum produced carotenoid-based plumage coloration that was significantly less red and less saturated than that of noninfected males. These observations validate a necessary condition of the Hamilton-Zuk hypothesis, but heritable resistance to the pathogens we examined remains to be demonstrated.

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 = 1% 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.Key words: Chemotherapy; Metastasis; Radiotherapy.umors of the nasal cavity and paranasal sinuses com-T prise less than 2% of canine neoplasms.' Most of these tumors are malignant and associated with a poor prognosis.l-3 Nasal carcinomas occur more frequently than sarcomas in all domestic species.I Of carcinomas, adenocarcinoma is the most common nasal tumor in the dog.' Treatment options include surgery, chemotherapy, and ortho-or megavoltage teletherapy, used singly, or as combination therapies. Radiotherapy is employed most commonly and has been reported to provide better clinical responses than surgery or chemotherapy alone6-x; however, results have been uniformly poor. Extensive disease and bony destruction often preclude effective treatment. Reported mean survival time without treatment was 5 months.' A median survival.time of 23 months with radiotherapy was reported in 1 study.7 Subsequent studies indicated median survival of 16.5 months or less.6.".1"In previous reports of nasal tumors in the dog, tumors were not staged and dogs with metastasis were excluded.',h,'o Failure to recognize or include animals with metastatic lesions thus limited the ability to examine tumor stage as a prognostic indicator. Furthermore, previous reports included multiple tumor type^^,^,^,^,^,^^ and considerable variation in radiation dose and t~p e .~.~ In an effort to more accurately determine the prognostic significance of tumor stage for dogs with nasal tumors, this study was limited to 1 tumor type for which complete staging was performed. The efficacy of surgery, chemotherapy, and radiation therapy in the treatment of nasal adenocarcinoma was examined.