0–7–21 Radiation Therapy for the Treatment of Canine Oral Melanoma

Eighteen dogs with malignant melanoma of the oral cavity were treated with high-dose per fraction (0–7–21) radiation therapy. Eight hundred cGy was administered on days 0, 7, and 21 for a total dose of 2,400 cGy in 3 weeks. Of 17 dogs evaluated, 9 (53%) had a complete remission and 5 (30%) achieved a partial remission with an overall response rate of 83%. Local failure occurred in 2 of the 9 dogs where a complete response was initially observed. One dog died of intercurrent disease, and one died of metastatic disease without evidence of local recurrence. Five dogs are alive and free of disease 9 to nineteen months from the initiation of therapy. The 0–7–21 protocol was well-tolerated, and acute radiation reactions were low-grade and limited to the skin. The results of this study demonstrate that oral melanomas in dogs are responsive to radiation. 0–7–21 radiation therapy offers a viable alternative to radical excision, especially when tumor volume or location would require cosmetically or functionally debilitating surgery.     

COLLAGENASE CHEMONUCLEOLYSIS—A LONG TERM RADIOGRAPHIC STUDY IN NORMAL DOGS

Five clinically normal five year old dogs were used in this study. From a randomised table inter ver tebral discs were each injected with either collagenase or calcium chloride diluent. The surgically exposed cervical discs were injected with 50 units whereas thoracic and lumbar discs were injected under fluoroscopic guidance with 100 units of the enzyme. Postinjection radiographs revealed significant (p ≤ .05) disc space narrowing in enzyme injected discs. The cervical discs had the highest frequency of radiographic narrowing (87%) followed by the thoracic (70%) and lumbar (53%) discs. Spondylosis deformans developed at the sites of cervical enzyme injections. None of the dogs had neurologic abnormalities one year postinjection.     

Intra-articular tissue response to analytical grade metrizamide in dogs

The effect of analytical grade metrizamide (AM) injected into the canine stifle, for purposes of arthrography, was studied in 12 adult dogs using saline solution as the control solution injected into the contralateral joints. The AM was used at a concentration of 280 mg of iodine/ml and was administered at the dose of 0.3 ml/cm thickness of the stifle joint. For each joint, arthrocentesis was done before and 7 days after injection of either the contrast medium or saline solution. Physical, biochemical, and cytologic examinations were done on the synovial fluid while the synovial membranes and femoral articular cartilages were sectioned, stained, and examined for histopathologic changes. At the 95% confidence level, significant differences in the total and differential mononuclear cell counts were not seen between the AM- and saline solution-injected joints. However, some subtle changes in the synovial membranes were observed. Intra-articular injection of AM or saline solution initiated a mild inflammatory response, the AM causing slightly more response than the saline solution.     

Terrain controls on depressional soil distribution in a hummocky morainal landscape

In hummocky morainal landscapes, soil distribution in well-drained landscape positions tends to follow a consistent pattern. Soils in depressions, however, are more difficult to predict reliably. This study had two objectives: (1) to determine the parent material and landscape properties controlling the formation of the different depressional soils; and (2) to use these controls to identify quantitative, terrain-based predictors of soil type in depressions. Only two terrain attributes, specific dispersal area (SDA) and elevation relative to open water bodies, were required to distinguish three main soil groups: Gley Recharge, Non-gley Recharge, and Discharge soils.

Specific dispersal area is the downslope area draining flow from a given grid cell. Gley Recharge soils occur primarily at points with SDA of less than 2 m² m⁻¹, regardless of elevation within a given site, because most of the runoff flowing to a point with very low SDA values will pond or infiltrate vertically rather than flow downslope. Non-gley Recharge soils and Discharge soils both occur at points with SDA of greater than 2 m² m⁻¹. The majority of the Non-gley Recharge soils occur above 5-m elevation relative to an open water body and the majority of the Discharge soils occur below 5-m elevation relative to an open water body, reflecting the importance of solute cycling in the development of discharge conditions. Buried and depositional soils could not be predicted from current terrain attributes because their profile characteristics were derived from the paleosurface.     

Effectiveness of oxfendazole against early and later 4th-stage Strongylus vulgaris in ponies

Twenty pony foals (reared worm free), 6.5 to 10 weeks of age, were inoculated with Strongylus vulgaris and allocated to 5 groups, each with 4 foals. One week after inoculation, 1 group of 4 foals was given oxfendazole (OFZ) at a dosage rate of 10 mg/kg of body weight, another group was given 2 such treatments 48 hours apart, and a 3rd group was given a placebo. All treatments were administered by stomach tube. Three weeks later, foals were euthanatized and necropsied in a test for efficacy against early 4th-stage larvae. Oxfendazole was 80% and 94.9% effective against early 4th-stage S vulgaris with 1 and 2 doses, respectively. A 4th group of 4 foals was given 2 treatments of OFZ, 48 hours apart, about 8 weeks after inoculation, and a 5th group was given a placebo. These foals were euthanatized and necropsied 5 weeks after treatment in a test for efficacy against later 4th-stage larvae. Two doses of OFZ were 96.6% effective against later 4th-stage larvae.