Cutaneous vascular neoplasia in 15 cats: clinical, morphologic, and immunohistochemical studies.

Seven cases of cutaneous hemangioma and nine of cutaneous hemangiosarcoma were diagnosed from biopsy specimens of 15 Domestic Shorthairs of 5,091 cats that were examined by necropsy or biopsy during the 5-year period from 1 January 1986 through 31 December 1990. All but three cats were male. Tumor cells of both hemangiomas and hemangiosarcomas were immunoreactive for factor VIII-related antigen and for vimentin by the avidin biotin peroxidase complex method. In cats with a median age of 10 years, hemangiomas occurred in skin with pigmented hair in six of seven cases without apparent site predilection. These solitary tumors did not recur after excision although one cat (No. 3) subsequently developed cutaneous hemangiosarcoma at another site. Seven of nine hemangiosarcomas occurred in dermis and subcutis of the head, usually on the pinna. All five hemangiosarcomas of the head, for which cutaneous pigmentation could be determined, occurred in unpigmented skin. Cats with hemangiosarcoma had a median age of 12.5 years at the time of diagnosis. Metastasis has not been documented, but hemangiosarcoma has recurred, from 1 month to 2 years after excision, in 6/7 cats that were studied.     

Evaluation of outcome associated with subcutaneous and intramuscular hemangiosarcoma treated with adjuvant doxorubicin in dogs: 21 cases (2001-2006)

OBJECTIVE: To evaluate outcome associated with subcutaneous and intramuscular hemangiosarcomas treated with adjuvant doxorubicin in dogs. DESIGN: Retrospective case series. ANIMALS: 21 dogs. PROCEDURES: Records of dogs with histologically confirmed hemangiosarcoma, no detectable metastasis at initial evaluation, and adequate local tumor control were included. Age, sex, number of treatments, treatment interval, radiation therapy, and concurrent use of cyclophosphamide or deracoxib were evaluated for associations with disease-free interval (DFI) or survival time. Three to 6 cycles of doxorubicin were planned. Disease-free interval was defined as time of definitive surgery to time of local recurrence, metastasis, or both. Survival time was defined as the beginning of the DFI to time of death. RESULTS: 17 tumors were subcutaneous, and 4 were intramuscular. Median age was 9 years. Median weight was 31.1 kg (68.4 lb). Five dogs received adjuvant radiation therapy. Median DFI for subcutaneous tumors was 1,553 days (95% confidence interval [CI], 469 days to not estimable). Median DFI for intramuscular tumors was 265.5 days (95% CI, 123 to 301 days). Median survival time for subcutaneous tumors was 1,189 days (95% CI, 596 days to not estimable). Median survival time for intramuscular tumors was 272.5 days (95% CI, 123 to 355 days). For dogs with subcutaneous tumors, younger age (< 9 years) was associated with longer DFI and survival time. Dogs with subcutaneous tumors that did not receive radiation therapy had longer DFI. CONCLUSIONS AND CLINICAL RELEVANCE: Dogs with subcutaneous hemangiosarcoma had a more favorable outcome, compared with dogs with intramuscular hemangiosarcoma, when treated with adequate local control and adjuvant doxorubicin.     

A retrospective study of visceral and nonvisceral hemangiosarcoma and hemangiomas in domestic animals.

Cases of hemangiosarcoma submitted to the Colorado State University Veterinary Diagnostic Laboratory during a 6-year period were reviewed. Visceral hemangiosarcomas represent less than 2% of canine specimens submitted for histologic examination and nonvisceral hemangiosarcoma less than 1%. Most nonvisceral hemangiosarcomas of dogs occur in skin. Hemangiosarcomas are less common in cats and usually occur in skin. They are also rare in other animal species. Animals with nonvisceral hemangiosarcomas are usually mature; dogs and cats average 10 years of age. The tumors develop in many different locations, and there is no sex predilection. A wide variety of dog breeds are affected, but Italian greyhounds, greyhounds, and whippets are overrepresented. Clinical outcomes of 76 cases of nonvisceral hemangiosarcomas in dogs and cats were obtained from submitting veterinarians. Completeness of excision of a tumor is the most important factor that can be used in predicting clinical outcome for an affected dog or cat. In all cases in which the animals were clinically normal for at least 1 year after surgical removal of a nonvisceral hemangiosarcoma, the margins were reported to be free of neoplastic cells. Degree of differentiation, mitotic rate, size of tumor, and presence or absence of epidermal ulceration, mast cells, or solar elastosis did not correlate with clinical outcome.     

Epithelioid variant of hemangioma and hemangiosarcoma in the dog, horse, and cow

Epithelioid hemangiomas, hemangioendotheliomas, and angiosarcomas are well recognized histologic variants of endothelial tumors in humans that in the past have been confused with neoplasms of epithelial or histiocytic origin. We describe 12 epithelioid endothelial vascular tumors in 8 dogs, 3 horses, and 1 cow that share microscopic features with these tumors in humans. Ten tumors were located within the dermis and subcutis, 1 in the gastrocnemius tendon, and 1 in the skeletal muscle of the thigh. Key histologic features were the plump, epithelioid appearance of neoplastic endothelial cells and occasional cytoplasmic vacuolation, which rarely contained a single erythrocyte. Patterns of epithelioid endothelial cell growth ranged from conventional vasoformative structures to glandlike acini and short ducts to solid, sheetlike arrangements. All tumors were positive for endothelial markers: 12/12 (100%) were positive for von Willebrand factor with variable intensity and distribution and 9/9 (100%) were positive for CD31. All 12 were negative for cytokeratin. We subdivided these tumors into epithelioid hemangiomas (n = 3) and hemangiosarcomas (n = 9) based on conventional morphologic criteria, growth pattern (invasive or not), and metastasis (known in 1 case at the time of biopsy). Additional follow-up information obtained by a written questionnaire was available for 6/12 (50%) animals and revealed local recurrence in 3 animals (1 epithelioid hemangioma and 2 epithelioid hemangiosarcoma) and regional metastasis in 3 animals (all epithelioid hemangiosarcomas). This series represents a novel group of vascular tumors in domestic animals of which there are only 3 previous cases reported in the veterinary literature.     

Factor VIII-related antigen in canine endothelial neoplasms: an immunohistochemical study

Canine vascular tumors (47 hemangiomas, 36 hemangiosarcomas) were investigated for the endothelial cell marker factor VIII-related antigen (F VIII RAg). The primary antibody was a commercial rabbit anti-human (r/h) F VIII RAg antiserum. All (100%) hemangiomas and 32 (89%) of 36 hemangiosarcomas stained for F VIII RAg. One hemangiosarcoma (3%) was negative, and three tumors (8%) were equivocal in staining. Rarely, the interpretation of stained immature endothelial cells was difficult. The r/h F VIII RAg antibody was a positive marker of normal, reactive, and neoplastic endothelial cells in the dog.     

Feline conjunctival hemangioma and hemangiosarcoma: a retrospective evaluation of eight cases (1993-2004)

The purpose of this retrospective study was to evaluate feline primary conjunctival vascular tumors of endothelial origin. Eight cases (six hemangiomas, two hemangiosarcomas) from a collection of 3460 feline submissions between 1993 and 2004 were evaluated using routine hematoxylin and eosin (H&E). Signalment, location, size, duration, epithelial pigmentation, margins, adjuvant therapy, outdoor activity, and geographic location, comparing ultraviolet (UV) radiation levels by state, were recorded. Follow-up information was available for five cases. In this study, the average age was 10.6 years, with neutered males over-represented. The Domestic Short-haired cat was most commonly affected. The most common anatomic site was the nictitating membrane, with the left eye preferentially affected. The average size and duration, prior to presentation, was 7.5 mm and 4.4 months, respectively. Seven of eight cases were devoid of epithelial pigmentation in nonaffected areas and the majority of cases were from states with high annual UV-light exposure. Only cases of hemangiosarcoma underwent surgical re-excisions following incomplete excision; however, no further recurrences were reported. No cases evaluated had evidence of metastatic disease at the time of excision. Surgical excision alone may be curative. However, recurrence is possible. These tumors demonstrate similar predilection sites and involvement of nonpigmented epithelium, as is true in canine cases, which may relate to risk factors as well.     

Canine conjunctival hemangioma and hemangiosarcoma: a retrospective evaluation of 108 cases (1989-2004)

Canine conjunctival tumors of vascular endothelial origin are common, although under-reported. The purpose of this study was to evaluate the epidemiology of and potential risk factors for these tumors. This study evaluated 108 cases (70 hemangiomas, 38 hemangiosarcomas) from 8300 canine submissions between 1989 and 2004. Signalment, location, pigmentation, size, duration, diagnosis, margins, ancillary therapy, and geographic location were recorded. Follow-up information was available for 49 cases. Each case was matched with two unaffected controls and compared using logistic regression analysis. Average age upon presentation was 8.6 years; there was no sex predilection. Risk of conjunctival tumors was statistically different among breed groups (P = 0.0010), demonstrating a propensity to occur in groups likely to have increased outdoor activity. Primary involvement occurred within nonpigmented epithelium along the leading edge of the nictitating membrane (41/108) and temporal bulbar conjunctiva (33/108). The etiology remains unknown; however, the strong site predilection, involvement of nonpigmented epithelium, and development within specific breed classes strongly suggest ultraviolet (UV) light as a significant risk factor. In a full-logistic model including breed, gender, age, and UV exposure, UV was not a statistically significant variable (P = 0.1215). In a reduced-model including UV only, significance was approached (P = 0.0696) and posthoc contrast demonstrated a significant linear trend with increasing UV exposure (P = 0.0147). In separate analysis of risks associated with hemangiosarcoma, compared with hemangioma, breed was not significant while increasing UV exposure was significant (P = 0.0381). Early surgical therapy is recommended and may be curative; however, recurrence is possible and more likely with hemangiosarcomas (11/20).     

Prevalence of hemangiosarcoma in anemic dogs with a splenic mass and hemoperitoneum requiring a transfusion: 71 cases (2003-2005)

OBJECTIVE: To determine prevalence of splenic hemangiosarcoma in anemic dogs with a splenic mass and hemoperitoneum requiring a transfusion and to identify factors that could differentiate between dogs with hemangiosarcoma and dogs with other splenic masses at the time of hospital admission. DESIGN: Retrospective case series. ANIMALS: 71 dogs. PROCEDURES: Medical records, blood bank logs, and histologic reports of dogs with a splenic mass and hemoperitoneum that required a transfusion between 2003 and 2005 were reviewed. Dogs that received a transfusion of packed RBCs, were splenectomized, and had a definitive histologic diagnosis were included. RESULTS: Signalment of dogs was similar to that in other reports. Malignant splenic neoplasia was identified in 54 of 71 (76.1%) dogs, whereas 17 of 71 (23.9%) dogs had a benign splenic lesion. Of 54 dogs with malignant splenic neoplasia, 50 (92.6% [70.4% of all dogs]) had splenic hemangiosarcoma. In addition, dogs with splenic hemangiosarcoma had significantly lower total solids (TS) concentrations and platelet counts at admission. Finally, hemoperitoneum was strongly associated with a diagnosis of splenic hemangiosarcoma. CONCLUSIONS AND CLINICAL RELEVANCE: In this clinical population of dogs, prevalence of hemangiosarcoma was higher than in other studies. Dogs with hemangiosarcoma in this study had significantly lower TS concentrations and platelet counts at the time of admission, compared with values for dogs with other splenic masses. No other markers were useful in differentiating dogs with hemangiosarcoma. It is important to discuss the prevalence of and poor prognosis associated with hemangiosarcoma with owners when they are contemplating whether to proceed with treatment.     

Evaluation of hemostatic defects secondary to vascular tumors in dogs: 11 cases (1983-1988)

Two populations of dogs with cutaneous hemangiomas and hemangiosarcomas were evaluated retrospectively. One population consisted of 96 dogs seen at the Veterinary Medical Teaching Hospital at the University of California, Davis. The second population consisted of 116 dogs that had skin biopsy specimens submitted to a private veterinary diagnostic laboratory for histologic diagnosis. Nine dogs from the teaching hospital and 2 dogs, from which samples had been submitted to the veterinary diagnostic laboratory, developed hemostatic defects in association with the tumors. Hemostatic defects included hemorrhage directly from the tumor, thrombocytopenia, hypofibrinogenemia, and findings associated with disseminated intravascular coagulation. Because bleeding during surgery can develop in animals with hemostatic defects, dogs with one or more tumors suspected of being vascular in origin should have platelet numbers and hemostatic analytes evaluated prior to surgery, especially if petechiae or ecchymoses are evident.     

Histologic features and clinical outcomes of melanomas of lip, haired skin, and nail bed locations of dogs.

Outcomes, signalments, and the relationship of histologic features with the outcome of melanomas located in lip, nail bed, and haired skin of dogs were reviewed. These melanomas were diagnosed as benign or malignant based on histologic features. Melanomas of the lip arose from mucous membrane in most cases. 32 dogs with lip melanomas that had histologic features of malignancy, 22 died because of the tumor within 1 year and 10 were tumor free for at least 1 year following removal. Of 10 dogs with melanomas with benign histologic features on the mucous membrane of the lip, 9 were tumor free for at least 1 year. Of 4 dogs with benign appearing tumors of the haired skin of the lip, 3 were tumor free for at least 1 year. Melanomas with histologic features of malignancy occurred in many locations of haired skin, and 11 of 24 dogs were tumor free for at least 1 year. All nail bed melanomas had histologic features of malignancy and all invaded the third phalanx, but 6 of 14 dogs were tumor free for at least 1 year after amputation of the digit. Among these dogs, the 1-year survival rates for tumors classified as malignant by histologic features were 69% for lip, 46% for haired skin, and 43% for nail bed. However, the clinical outcome of an individual malignant tumor could not be predicted accurately by any specific histologic features.     

Black hair follicular dysplasia in Large Münsterländer dogs: clinical, histological and ultrastructural features

Four Large Münsterländer cross‐bred dogs affected with black hair follicular dysplasia (BHFD) and one unaffected control littermate were observed, and skin was sampled weekly over the first 19 weeks of life. Affected dogs were born with silvery grey hair, a consequence of melanin clumping in the hair shafts. Hair bulb melanocytes were densely pigmented, and contained abundant stage IV melanosomes but adjacent matrix keratinocytes lacked melanosomes. Melanin clumping was not prominent in epidermal melanocytes in the haired skin but occurred in the foot pads. Follicular changes progressed from bulbar clumping, clumping in the isthmus/infundibulum and finally to dysplastic hair shafts. Alopecia developed progressively in pigmented areas. Silver‐grey hair, melanin clumping, accumulation of stage IV melanosomes within melanocytes and insufficient melanin transfer to adjacent keratinocytes are also classic features of human Griscelli syndrome. The underlying cause in Griscelli syndrome is a defect of melanocytic intracellular transport proteins leading to inadequate and disorganized melanosome transfer to keratinocytes with resultant melanin clumping. In view of the correlation in the phenotype, histology and ultrastructure between both disorders, a defect in intracellular melanosome transport is postulated as the pathogenic mechanism in BHFD.     

Mast cell distribution,epidermal thickness and hair follicle density in normal canine skin: possible explanations for the predilection sites of atopic dermatitis?

Mast cell counts, epidermal thickness and hair follicle density were quantified in toluidine blue stained sections of normal skin from 20 different body regions in 10 dogs and compared to the predilection sites of canine atopic dermatitis. Mast cell distribution varied significantly from site to site (P < 0.0001) and counts in the superficial dermis were significantly higher than the deeper dermis (P < 0.05). Mast cell counts were highest in the medial and lateral pinna (mean 10.4–11.3 per high power field, HPF) and in the ventral interdigital skin of the hind and fore feet (mean 9.2–9.5 per HPF). Counts in these regions were at least 150% higher than all the other sites (means ranging between 2.9 and 6.0 per HPF). Variations in mast cell counts, epidermal thickness or hair follicle density did not adequately explain the predilection sites of canine atopic dermatitis. However, the results provide some evidence that cutaneous mast cell distribution may be involved in the frequent occurrence of ear and foot pruritus in this disease.     

Cutaneous Hemangiosarcoma in 25 Dogs: A Retrospective Study

Hemangiosarcomas confined to the skin and underlying muscle were surgically excised in 25 dogs. Tumors were staged based on their histological location (ie, dermal, hypodermal, and deep). Dermal (stage I) hemangiosarcomas were small, most commonly ventral-abdominal or preputial in location, and were associated with prolonged survival times (median survival, 780 days). Tumors with hypodermal (stage II) and underlying muscular involvement (stage III) were grouped together because of their larger size, bruise-like appearance, lack of anatomic predilection, biological behavior, and shorter survival times (median survival of 172 and 307 days for dogs with stages II and III, respectively). We conclude that dermal hemangiosarcomas may be effectively treated with surgery alone, whereas hemangiosarcomas located within the hypodermal tissues bear a poor prognosis and warrant wide surgical excision with adjuvant chemotherapy.     

Adjuvant anthracycline‐based vs metronomic chemotherapy vs no medical treatment for dogs with metastatic splenic hemangiosarcoma: A multi‐institutional retrospective study of the Italian Society of Veterinary Oncology

Treatment options for dogs with metastatic (stage III) splenic hemangiosarcoma are limited. A doxorubicin‐based chemotherapy regimen is commonly administered; however, there are no published data to support this practice. The aim of this study was to investigate the impact of maximum‐tolerated‐dose chemotherapy (MTD), metronomic chemotherapy (MC) and no adjuvant treatment on outcome in dogs with stage III splenic hemangiosarcoma undergoing splenectomy. Medical records of dogs with stage III splenic hemangiosarcoma that underwent splenectomy followed by MTD chemotherapy, MC or no adjuvant treatment were retrieved. Time to progression (TTP), survival time (ST) and toxicity were evaluated. One hundred three dogs were identified: 23 received adjuvant MTD, 38 MC and 42 were not medically treated. Overall median TTP and ST were 50 (95% confidence interval [CI], 39‐61) and 55 days (95% CI, 43‐66), respectively. Dogs treated with adjuvant MTD had a significantly longer TTP and ST compared with dogs receiving MC (median TTP, 134 vs 52 days, P = .025; median ST, 140 vs 58 days, P = .023, respectively). Dogs treated by splenectomy only had the shortest median TTP (28 days) and ST (40 days). However, treatment‐related adverse events (AEs) were significantly more frequent in the MTD group (P = .017). The outcome for dogs with metastatic splenic hemangiosarcoma is poor. While MTD showed greater efficacy compared to MC, toxicity was higher in this group. Treatment‐related AEs need to be carefully balanced against this modest survival prolongation when offering adjuvant MTD to dogs with advanced stage hemangiosarcoma.     

The effects of thyroid hormones on the skin of beagle dogs

The effects of hypothyroidism on canine skin were determined by comparing morphologic, morphometric, and hair cycle differences in skin biopsy samples from 3 groups of age- and gender-matched Beagle dogs: (1) euthyroid dogs; (2) dogs made hypothyroid by administration of 131I; and (3) dogs made hypothyroid and maintained in a euthyroid state by treatment with synthetic thyroxine. After 10 months of observation, there was slower regrowth of hair 2 months after clipping in the untreated-hypothyroid dogs. Untreated-hypothyroid dogs had a greater number of follicles in telogen and fewer hair shafts (ie, a greater number of hairless telogen follicles) than did the control group. The control dogs had a greater number of telogen follicles but the same number of hair shafts as the treated-hypothyroid group. Treated-hypothyroid dogs had the greatest number of follicles in the growing stage of the hair cycle (anagen). This study suggests that, at least in Beagles, induced hypothyroidism does not affect the pelage as dramatically as has been described in naturally occurring disease. This is because normal Beagles retain hair shafts in follicles for long periods, and the alopecia of hypothyroidism appears to evolve slowly because of the prolongation of this haired telogen stage. The evaluation of thyroxine-treated hypothyroid dogs demonstrates that thyroid hormone supplementation of Beagle dogs with induced hypothyroidism stimulates hair growth.     

Quantitation of house dust mite allergens (Der f 1 and group 2) on the skin and hair of dogs

OBJECTIVE: To determine the concentration of house dust mite (HDM) allergens, Der f 1 and group 2, on the skin and hair of dogs and whether associations exist between the presence of Der f 1 and group 2 allergens on the skin and hair of dogs and household and dog characteristics. ANIMALS: 63 pet dogs from 50 homes. PROCEDURE: Dogs were weighed and body surface area in square meters was determined. Skin and hair samples were obtained by vacuuming dogs. Collected dust was analyzed by use of standard ELISA techniques. RESULTS: HDM allergen was detected in 21 of 59 skin and hair samples. Presence of group 2 allergen on skin and hair of dogs was significantly associated with long hair, compared with short or medium length hair. Median house dust sample concentrations of Der f 1 and group 2 allergens were high in homes with dogs that had skin and hair samples that were positive for Der f 1 and group 2 allergens. Dogs with skin and hair samples that were positive for Der f 1 and group 2 allergens resided in homes with a high number of house dust samples that were positive for Der f 1, group 2, or both allergens and in homes with a mean house dust sample allergen concentration of > or =2 microg/g of dust. CONCLUSIONS AND CLINICAL RELEVANCE: Associations exist between environmental HDM allergen concentrations and HDM allergens on the skin and hair samples of dogs. Environmental allergen load is a major factor in accumulation of allergens on the skin and hair of dogs.     

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.     

Microscopic anatomy of the skin of the woodchuck (Marmota monax): comparison of woodchuck hepatitis virus-infected and non-infected animals.

Thirty-three woodchucks were used in this study. Seventeen animals were healthy adults, not infected with woodchuck hepatitis virus (WHV); 10 were healthy adults infected with WHV; 4 were noninfected neonates; 2 were infected neonates. Within the 4 groups of woodchucks, no histologic differences were detected on the basis of sex or age. Neither were histologic findings different between infected and noninfected woodchucks of similar ages. The average thickness of skin (as measured from the skin surface to the inner limit of the dermis) from the general haired body area was 2394 microns. The skin was thickest on dorsal body areas, and gradually became thinner on ventral body and medial limb areas. The epidermis consisted of 4 layers: stratum basale, stratum spinosum, stratum granulosum, and stratum corneum. A stratum lucidum was present only in the epidermis of the footpads. There was no clear distinction between the superficial dermis and the deep dermis, except for the subtle differences in arrangement and size of collagen fibers. Elastic fibers were seen throughout the dermis, being more prominent in the superficial portion. Both compound and simple hair follicle arrangements were seen, with compound being more common. The arrectores pilorum muscles were largest in the skin over the dorsal body areas. Sebaceous glands were present either within the outer root sheath of hair follicles or in the dense connective tissue surrounding hair follicles. No apocrine sweat glands were found. However, there were abundant eccrine sweat glands in the subcutaneous fat of the footpads.     

Intracranial Lesions in Dogs With Hemangiosarcoma

A retrospective analysis of 85 dogs with hemangiosarcoma (HSA) that underwent complete necropsy, including gross examination of the brain, was conducted. Grossly identifiable intracranial lesions were present in 17 dogs. Twelve of 85 dogs (14.2%) had brain metastases. Four of 85 dogs (4.7%) had hemorrhagic lesions and/or ischemic necrosis without identifiable tumor. One dog had a primary central nervous system tumor. Signs of intracranial disease were present in six of 85 dogs (7.1%) with HSA; four had brain metastases and two had nonneoplastic lesions. Metastases had a propensity for cerebrum and gray matter. Dogs with brain metastases had more widely disseminated disease than dogs without brain metastases (P less than 0.001). Dogs with pulmonary metastases were at greater risk for developing brain metastases than dogs without pulmonary metastases (odds ratio = 8.31). Although thoracic radiography accurately identified ten of 12 dogs (83%) with pulmonary metastases, too few cases were available to assess the applicability/accuracy of thoracic radiography in predicting the presence or absence of brain metastases in dogs with malignancy and signs of intracranial disease.     

Carcinoma of the apocrine glands of the anal sac in dogs: 113 cases (1985-1995)

OBJECTIVE: To characterize the signalment, clinical signs, biological behavior, and response to treatment of carcinoma of the apocrine glands of the anal sac in dogs. DESIGN: Retrospective study. ANIMALS: 113 dogs with histologically confirmed carcinoma of the apocrine glands of the anal sac. PROCEDURE: Data on signalment, clinical signs, and staging were reviewed and analyzed along with treatment modality for potential association with survival time. RESULTS: Sex distribution was approximately equal (54% female, 46% male). One hundred four dogs underwent treatment consisting of surgery, radiation therapy, chemotherapy, or multimodal treatment. Median survival for treated dogs was 544 days (range, 0 to 1,873 days). Dogs treated with chemotherapy alone had significantly shorter survival (median, 212 days) than those receiving other treatments (median, 584 days). Dogs not treated with surgery had significantly shorter survival (median, 402 days) than those that underwent surgery as part of their treatment (median, 548 days). Dogs with tumors > or = 10 cm2 had significantly shorter survival (median, 292 days) than dogs with tumors < 10 cm2 (median, 584 days). Hypercalcemia was identified in 27% (n = 29) of dogs, and those dogs had significantly shorter survival (median, 256 days), compared with those that were normocalcemic (median, 584 days). Dogs with pulmonary metastasis had significantly shorter survival (median, 219 days) than dogs without evidence of pulmonary metastasis (median, 548 days). CONCLUSIONS AND CLINICAL RELEVANCE: Unlike most previous reports, this study revealed an approximately equal sex distribution, and results suggest a more favorable prognosis.