Use of cytology for tumor diagnosis in private veterinary practice.

Cytologic and histologic services were offered without charge to veterinarians in the greater Tulsa area by the Tulsa Registry of Canine and Feline Neoplasms. During the first 3 years of operation, all veterinarians treating dogs or cats used the histologic service and slightly less than one-half used the cytologic service. The number of cytologic accessions increased 77% during the 2nd year and 27% during the 3rd year. For corresponding years, the increase in histologic accessions was 5% and 11%. The 7 hospitals from which 79% to 90% of the cytologic specimens were received were compared with the 8 to 14 hospitals that used cytologic service infrequently. The frequency of use of cytology was not related to number of veterinarians in the hospital, number of animals seen in the hospital, or number of tissues received by the Registry from the hospital. The order of frequency of the most numerous cytologic specimens was fine-needle aspirations of masses in or beneath the skin, mammary preparations, effusion sediments, fine-needle aspirations from lymph nodes, and urine sediments.

Bradycardia associated with meningioma in a dog.

Clinical signs of bradycardia and syncope, associated with intracranial meningioma, were observed in a 4-year-old female Irish Setter. Electrocardiographic abnormalities confirming bradycardia and suggestive of sinoatrial arrest were demonstrated. Return to a normal heart rate and sinus rhythm after administration of atropine IV indicated that increased vagal tone was responsible for the observed abnormalities. Neither glycopyrrolate nor propantheline bromide therapy was successful in controlling bradycardia and syncope. Necropsy findings included the demonstration of a 3 X 2 X 2-cm mass on the ventral aspect of the right half of the brain. This mass covered half of the mammillary body and extended as a thick reddish brown membrane extending over the piriform lobe of the cerebrum, optic chiasm, and longitudinal fissure. Histologically, the mass was identified as a meningotheliomatous meningioma.

Acid mucopolysaccharides in mammary tumors of dogs.

The predominant acid mucopolysaccharides found in selected epithelial mammary tumors of dogs stained with alcian blue and were labile to hyaluronidase digestion. These histochemical characteristics identified them as hyaluronic acid, chondroitin-4- and chondroitin-6-sulfate. The intensity of the staining of these acid mucopolysaccharides varied in a transitionary process from a precartilaginous to a pseudocartilaginous intercellular matrix to mature hyaline cartilage. The tumor acid mucopolysaccharides were indistinguishable from those associated with formation of cartilage in developing mammals; such cartilage is reported to be produced only by cells of mesodermal origin. There was no evidence to suggest transitional changes in myoepithelial cells, neoplastic epithelial cells or their components that could contribute to the formation of the acid mucopolysaccharides. It was concluded that the heterotopic tissues (cartilage, bone and fibrous connective tissue) in the epithelial mammary tumors were derived from cells of mesodermal origin and formed the adjacent stroma in areas of neoplasia.

Frequency of canine and feline tumors in a defined population.

The Tulsa Registry of Canine and Feline Neoplasms was the second animal tumor registry in the United States concerned with a defined population in a delimited geographic area. Only tumors histologically confirmed by registry pathologists were included in frequency statistics based on the annual dog and cat population presented to veterinarians. During the first registry year, about 1% of the 63,504 dogs and 0.5% of the 11,909 cats had one or more primary tumors. While the incidence rate for malignant tumors in dogs was similar to that in cats, the incidence of benign tumors of dogs was over 10 times that of cats. The most common tumors were sebaceous adenoma in dogs and lymphosarcoma in cats. Mammary cancer was the most common malignant tumor in dogs. Mammary tumors of female dogs were significantly more frequent in Pointers, Poodles and Boston Terriers, in that order, than in other breeds. A greater incidence of mammary tumors among intact compared to spayed female dogs was seen for virtually every age group except in the Pointer breed.