Clinical Evaluation of Three Surgical Methods for Treatment of Caudal Cervical Spondylomyelopathy of Dogs

Sixty-four dogs with caudal cervical spondylomyelopathy (CCSM) caused by chronic degenerative disc disease were treated with ventral decompression (n = 20), linear traction and interbody screw stabilization (n = 7), or linear traction and plastic plate stabilization (n = 37). Interbody screw stabilization was ineffective in treating CCSM because of an unacceptably high rate of implant failures. Ventral decompression or linear traction and plastic plate stabilization were effective in the treatment of most patients with mild to moderate neurologic deficits (neck pain, paraparesis, or ambulatory tetraparesis). Although these techniques were also used successfully in some patients with severe neurologic deficits (weakly ambulatory tetraparesis or nonambulatory tetraparesis), variable success rates and prolonged postoperative recovery periods were noted.     

RADIOGRAPHIC EVALUATION OF FELINE APPENDICULAR DEGENERATIVE JOINT DISEASE VS. MACROSCOPIC APPEARANCE OF ARTICULAR CARTILAGE

Degenerative joint disease (DJD) is common in domesticated cats. Our purpose was to describe how radiographic findings thought to indicate feline DJD relate to macroscopic cartilage degeneration in appendicular joints. Thirty adult cats euthanized for reasons unrelated to this study were evaluated. Orthogonal digital radiographs of the elbow, tarsus, stifle, and coxofemoral joints were evaluated for the presence of DJD. The same joints were dissected for visual inspection of changes indicative of DJD and macroscopic cartilage damage was graded using a Total Cartilage Damage Score. When considering all joints, there was statistically significant fair correlation between cartilage damage and the presence of osteophytes and joint‐associated mineralizations, and the subjective radiographic DJD score. Most correlations were statistically significant when looking at the different joints individually, but only the correlation between the presence of osteophytes and the subjective radiographic DJD score with the presence of cartilage damage in the elbow and coxofemoral joints had a value above 0.4 (moderate correlation). The joints most likely to have cartilage damage without radiographic evidence of DJD are the stifle (71% of radiographically normal joints) followed by the coxofemoral joint (57%), elbow (57%), and tarsal joint (46%). Our data support radiographic findings not relating well to cartilage degeneration, and that other modalities should be evaluated to aid in making a diagnosis of feline DJD.     

Luxation of the Canine Shoulder Joint to Maximize Exposure for Treatment of Osteochondritis Dissecans

Luxation of the humeral head by internal rotation of theforelimb with the shoulder joint in flexion will maximize exposure of the humeral head for treatment of osteochondritis dissecans of the canine shoulder. The procedure was performed on 51 normal dogs and on 13 shoulders of 11 dogs with osteochondritis dissecans. Postoperative evaluation was obtained in all 51 normal dogs and 8 clinical patients. Postoperative seromas were seen in two dogs; one was presumed to be due to reaction to the suture material used, and the other to unrestricted exercise during the immediate postoperative period. There were no other complications. The time for recovery to normal ambulation was similar to those reported for other approaches.     

Nonlymphomatous Hepatobiliary Masses in Cats: 41 Cases (1972 to 1991)

The medical and necropsy records of 41 cats diagnosed with nonlymphomatous hepatobiliary (NLHB) masses, including neoplasia and cysts, were reviewed. Overall, benign masses (n = 27) were more common than malignant ones (n = 14). The single most common malignancy was cholangiocellular carcinoma. The median age at diagnosis was significantly lower ( P < .01) for cats with malignant rather than benign disease. Clinical signs associated with hepatobiliary neoplasia were usually vague and included lethargy, vomiting, and anorexia, often present for at least 2 weeks before presentation. Benign masses were an incidental finding in significantly more ( P < .01) of the cases than were malignant masses. Median values for alanine aminotransferase (ALT), aspartate aminotransferase (AST), and total bilirubin were significantly higher ( P < .05) in cats with malignant versus benign masses. The prognosis for malignant disease was poor, with 86% of the cats dying or being euthanatized during hospitalization. Cats with benign disease that underwent exploratory celiotomy were more likely to recover and warranted a more favorable prognosis than cats with malignant tumors. Factors associated with malignancy included age at presentation, presence of clinical signs at presentation, and specific serum chemistry changes.     

Titratable Acids and Bases in Tree and Shrub Leaf Litters

Acidity of aqueous extracts of several tree and shrub leaf litterswas determined by titration to pH 7 with 0.01N NaOH. Bases weredetermined by back titration of 0.05N HCl extracts of groundlitters and after ashing. Lowest acidity was found in the broadleavedspecies (except sycamore) and western red cedar; greatest aciditywas found in western hemlock, grand fir, and one sample of Douglasfir. Largest contents of ash bases were found in some broadleavesplus western red cedar; the smallest contents were in most ofthe conifers. Excess ash bases (ash bases minus acidity) weregreatest in elm, hawthorn, western red cedar, hazel, willow,ash, and southern beech, and were smallest in western hemlock,Douglas fir, lodgepole pile, Sitka spruce, grand fir, hybridlarch, Scots pine, and Norway spruce. Acidity, directly titratableand ash bases, and excess ash bases showed significant, andin some cases quite large, variation between sites for somespecies. There is some support for the suggestion that excessash bases are greater in mull-forming than in mor-forming litters.Acidity was significantly greater for litters collected drythan for those collected wet. Litters which were stored airdry for several months showed increased acidity compared withtheir initial values.     

The genetic control and expression of specificity in Bremia lactucae (lettuce downy mildew)

The inheritance of specific virulence in Bremia lactucae was studied in crosses involving 12 heterothallic isolates of the fungus. In one cross, virulence to eight of the II specific resistance factors examined segregated in the F₁ generation. Although there were exceptions, most of the data were consistent with the hypothesis that pathogenicity was controlled by independent single loci with avirulence dominant to virulence. Linkage between loci determining virulence on R2 and R11 was confirmed. Loci controlling virulence on R5 and R8 also appeared to be linked but these may be identical R-factors. Contrary to a previous suggestion, the locus determining virulence to R10 was independent of that for R5/R8. The expression of virulence to three R-factors (Rl, R4 and R5/R8) was influenced by independent second loci. The presence of a dominant allele at the second locus inhibited avirulence. The expression of avirulence on R6 seemed to be influenced by modifier genes and environment in some isolates. Although the cultivars Mildura, Bourguignonne, Sucrine and Captain were originally thought to contain a single resistance factor, these data suggest that Sucrine carries R5/R8 in addition to R10 whilst Mildura may carry Rl in addition to R3. The stock of Bourguignonne appeared to be a mixture of resistance genotypes. The data add additional support to the suggestion that Capitan (Rll) may carry two resistance factors.