Opacity and lucency sign of the seventh lumbar vertebra in dogs.

A curvilinear opacity of the seventh vertebral arch and an adjacent focal lucency of the seventh lumbar vertebral body were incidentally noted in routine radiographs. The aim of this study was to analyze this radiographic absorption pattern using a sample of 51 dogs. Images of the bony surface of three macerated lumbosacral junctions were compared to their laterolateral radiographs and computed tomographic (CT) scans. Additional 48 lateral radiographic projections were reviewed for presence or absence of L7 opacity and lucency, length of the L6 and L7 vertebral bodies, vertebral disc disease, osteochondrosis, or spondylosis. Retrieved data were compiled and statistically analyzed. Radiographs and CT scans of the macerated bones revealed that the L7 pedicle had thickened layers of compact bone and the adjacent vertebral notch varying depth and extension. Superimposition of the pedicle on the vertebral body resulted in a curvilinear opacity (L7 opacity), the vertebral notch caused the focal lucency (L7 lucency). These findings were present in 69% of the reviewed radiographs and were found to be significantly associated with L6-L7 length ratios of less than 0.86 (P = 0.003). It is hypothesized that the changes correspond with normal anatomic morphology of the seventh lumbar vertebra plus adaptive bone remodelling. The importance of this study is that it could help avoid misinterpretation of this appearance as a pathologic condition.

Canine isosporosis - epidemiology of field and experimental infections.

Isospora spp. are the causative agents of canine isosporosis. Of the 3590 diagnostic samples from Austrian dogs (< or = 2 years old), 8.7% contained Isospora oocysts, 78% of which from dogs up to 4 months of age. Non-haemorrhagic and haemorrhagic diarrhoea were significantly more prevalent in Isospora-infected animals than in coccidia-negative ones. Twelve of 15 litters from a large commercial dog breeding unit (examined from the third to the 10th week of life) also excreted Isospora (average prevalence: 36.4%) in intensities from 333 to 35,000 oocysts per gram of faeces (opg). In experimental trials 26 3-week-old Beagle puppies were infected with low (600-6000), medium (10,000) or high (20,000) dose of Isospora ohioensis-group or Isospora canis field isolates. Additionally 21 puppies were infected as above and treated with a symmetrical triazintrione. Parasitological and clinical parameters were examined. The two Isospora species differed significantly concerning intensity and duration of excretion. The pre-patent period was 6-7 days for I. ohioensis and 10-12 days for I. canis. The latter species showed significantly longer excretion and higher opg. This was not influenced by simultaneous infections with both species. Individual patterns of faecal consistency were very variable, irrespective of the infection dose. Treatment significantly reduced both the intensity and the duration of oocysts excretion as well as diarrhoea in comparison with the infected, untreated group and thus proved to be effective against coccidiosis in experimental infections.