MAGNETIC RESONANCE IMAGING OF OCULAR AND ORBITAL DISEASE IN 5 DOGS AND A CAT

Magnetic resonance (MR) images were acquired in five dogs and one cat with ocular and orbital disease. MR images were obtained in the dorsal or oblique dorsal, and oblique sagittal planes. Pathologic changes identified in MR images included inflammatory lesions, cystic structures, and neoplasms. All abnormalities were readily apparent in TI-weighted images. MR findings in affected animals were often similar in signal intensity, location, and growth pattern to those found in people with comparable diseases. Although no MR changes were considered pathognomonic for a given disease, MR imaging provided detailed information on the homogeneity, extent and invasiveness of the lesions.     

Effect of spraying techniques on the brown rot of peach fruit,and on black spot,powdery mildew and the two-spotted mite of apple trees

Application by hand-held equipment of the commercially recommended doses of proprietary formulations of captan (9.0 g a. i. per tree), mancozeb (10.8 g a. i. per tree), oxythioquinox (1.1 g a. i. per tree), and cyhexatin (1.8 g a. i. per tree), in spray volumes ranging from 0.225 to 9.0 litres per tree, gave commercial control of the brown rot of peach fruit, and of black spot (apple scab), powdery mildew and the two-spotted mite (Tetranychus urticae) of apple trees. Commercial control was also obtained using a quarter of the recommended doses when applied in 0.225 or 2.25 litres per tree. The residue of oxythioquinox on the leaves, immediately after applying 1.1 g a. i. per tree, doubled as the volume of spray was reduced from 9.0 to 2.25 litres per tree, and increased further when the volume was reduced to 0.225 litres per tree. It is suggested that some of the oxythioquinox ran off the trees at the higher volumes, and that less run-off at lower volumes resulted in higher chemical residues.     

THE SEROLOGICAL RESPONSE OF CHICKENS TO OIL EMULSION VACCINES CONTAINING THE V4 STRAIN OF NEWCASTLE DISEASE VIRUS

SUMMARY Experiments were conducted with vaccines containing the V₄ strain of Newcastle disease virus (NDV). Both living aqueous vaccines and vaccines consisting of virus incorporated in an oil emulsion were used. The calculated dose of virus contained in the oil emulsion vaccine was 10^8,7 50% embryo infectious doses (EID₅₀) per bird dose. Haemagglutinin inhibition (HI) antibody levels of 8 are presumed protective. One-day-old chicks with low levels of maternal antibody were vaccinated intraocularly with 10^6,3EID₅₀ of live vaccine, and concurrently with oil emulsion vaccine. Presumed protective levels of antibody were present at two weeks post vaccination and were maintained for at least seven weeks longer. When adult birds 15 weeks old with no previous exposure to NDV were vaccinated intraocularly with 10^6,7EID₅₀ per bird, protective levels of antibody were produced within a week. Unvaccinated birds put in contact with the vaccinated birds produced similar antibody levels within 14 days. Revaccination with oil emulsion vaccine after antibody levels had fallen resulted in a rapid response with high levels of antibody. When antibody-free adult commercial birds with an unknown history of exposure to NDV were vaccinated intramuscularly with oil emulsion vaccine, high antibody levels were produced for at least 21 weeks. Concurrent intraocular inoculation with 10^7,0EID₅₀ live virus did not enhance the response. Natural infection of unvaccinated birds occurred during the experiment. This was detected by the presence of HI antibody levels of short duration. When antibody-free commercial birds were inoculated intramuscularly with oil emulsion vaccine containing 10^6,0, 10^7,0, or 10^8,0EID₅₀ per bird dose, 100% of birds inoculated with the highest dose produced presumed protective levels of antibody within two weeks, as compared with a 5-week delay when using the 10^7,0EID₅₀ per bird dose.     

Investigation of aberrant positive reactions to serological tests for bovine brucellosis

Fifty cattle thought not to be infected with Brucella abortus but giving persistent positive serological reactions, were investigated. It was concluded that only one of these was infected since exhaustive bacteriological examination produced only one isolate of B. abortus (strain 19) and none of the herds of origin was subsequently shown to be infected with brucellosis. Antibody was detected in stifle joint fluid of 15 cattle, which may have been stimulated by the presence of Strain 19 antigen that persisted in collagenous tissue long after the viable organisms had been eliminated.     

Vertebral canal and spinal cord mensuration: a comparative study of its effect on lumbosacral myelography in the dachshund and German shepherd dog

One hundred noncontrast spinal radiographic studies followed by myelography were evaluated to compare vertebral canal size and spinal cord location and size in a chondrodystrophic breed (50 Dachshunds) with those variables in a nonchondrodystrophic breed (50 German Shepherd Dogs). Measurements were made of the sagittal diameter (height) of the vertebral canal, sagittal diameter (height) of the spinal cord, and transverse diameter (width) of the spinal cord in the lumbar and sacral regions. Differences were detected in the craniocaudal location of maximal vertebral canal height and maximal spinal cord height. The spinal cords in the Dachshunds terminated further caudally than those in the German Shepherd Dogs. Location of maximal spinal cord width was different between the breeds, consistent with the apparent, more caudal termination of the cord in the Dachshunds. The ratio of spinal cord to vetebral canal heights was notably greater in the Dachshunds than in the German Shepherd Dogs. These differences in vertebral canal and spinal cord mensuration may influence the choice of radiographic technique and its interpretation. Injection sites may be selected further cranially in German Shepherd Dogs (L4-5) than in Dachshunds (L5-6).     

CANINE HIP DYSPLASIA

It is the purpose of this study to call attention to new bone production that often occurs early in the sequence of pathological changes associated with canine hip dysplasia. New bone production extending to bony remodeling, as well as femoral head subluxation, both occur in the sequence of pathologic changes associated with canine hip dysplasia. Subluxation is considered primary, while osteoarthrosis is a secondary feature, and both are used in the diagnosis of canine hip dysplasia. This report concerns the significance of the presence of a solitary bony osteophyte, or spur, that is frequently evident on the caudal aspect of the femoral neck as viewed on the conventional ventrodorsal projection. This report utilizes findings from pelvic radiographs of 605 dogs (five breeds). There was a greater frequency (54%)of this bony change in cases diagnosed radiographically as dysplastic than in cases diagnosed as normal(15%).Thus, it is suggested that this minimal radiographic change can be used as an indicator of early canine hip dysplasia, especially in the absence of subluxation of the femoral head.     

Gossypol as a toxicant in livestock

Many cases of gossypol toxicity have been misdiagnosed. The long-held belief that gossypol toxicity did not occur in ruminants has been a major hurdle to overcome. Field necropsies in which pulmonary congestion and edema were attributed to shipping-fever pneumonia, failure to examine the heart either grossly or microscopically, failure to believe that 200 ppm free gossypol could kill a calf, failure to believe that any age of sheep could suffer gossypol toxicity, and failure to believe that just because you fed the same thing last year, it will not cause a problem this year, all were factors in causing the misdiagnosis of this toxicity. Gossypol toxicity cases diagnosed will increase each year because of increased awareness among veterinarians. Continued research will help to increase our understanding of this multifactored toxin and, possibly, devise ways to detoxify it before it is utilized in a feed. Until then, it will have to be considered because it will continue to be present as a potential toxicant in the feed.