MAGNETIC RESONANCE IMAGING OF CEREBRAL CORTICAL NECROSIS (POLIOENCEPHALOMALACIA) IN A DOG

A 3-year-old neutered female mixed breed dog was examined because of severe, generalized seizure activity, tetraparesis, and encephalopathic signs. Cerebrospinal fluid (CSF) evaluation was unremarkable except for a mild increase in protein. Serum and CSF titers for infectious diseases were negative. Magnetic resonance (MR) imaging examination of the brain was performed and lesions were found within the cerebral gray matter of the temporal and parietal lobes. The lesions had increased signal intensity on T1, T2, and proton density-weighted images. There was mild inhomogeneous enhancement following intravenous contrast medium administration. Neurologic status improved and the seizures were well controlled, but the dog never regained normal mentation and euthanasia was performed 10 weeks after initial evaluation. At necropsy, severe cerebral cortical necrosis was found in the regions corresponding to the lesions seen on MR imaging examination. Large numbers of fat-containing macrophages (gitter cells) were found within these areas, and are thought to be responsible for the characteristic hyperintensity seen on the MR images.     

Physical characteristics and chemical composition of Greater Rhea (Rhea americana) eggs from wild and captive populations.

1. Eggs from wild and captive populations of Greater Rhea (Rhea americana) were studied to determine their physical and chemical characteristics. 2. Significant differences were found among populations in almost all chemical parameters studied, whereas within physical parameters only shell weight (as a proportion of the entire egg) and density showed differences. 3. Eggs from wild populations had the highest protein and linolenic acid and the lowest total lipid contents, while cholesterol levels of these eggs and of those from the largest captive area were the lowest.     

Enzyme-linked immunosorbent assay for screening the plasma residues of tetracycline antibiotics in pigs.

The recommended therapeutic doses of three kinds of tetracyclines, oxytetracycline (OTC, withdrawal period, 10 days), chlortetracycline (CTC, withdrawal period, 5 days) and tetracycline (TC, withdrawal period, 5 days), were each administered to a group of 15 pigs. Blood was sampled before drug administration and during the withdrawal period. The concentration of tetracyclines in plasma, determined by semi-quantitative ELISA, was compared with that of internal standard (10 ppb as oxytetracycline). The absorbance ratio of internal standard to sample (B/Bs) was employed as an index to determine the tissue residues in pigs. All 45 plasma samples from nontreated pigs showed negative in the residue of any of three tetracycline antibiotics. OTC was detected in plasma of pigs treated until the 8th day, CTC until the 4th day, and TC was detected until the 3rd day of its withdrawal period. The present study showed that the semi-quantitative ELISA easily be adopted in predicting tissue residues for tetracycline antibiotics in live pigs.     

Seed survival and predation of Anoda cristata in soyabean crops

Anoda cristata is a troublesome annual broad-leaved weed in summer crops in the rolling Pampa in Argentina; seeds are the only source of regeneration of this species. Seed persistence or depletion is the result of survival and loss processes, including predation. The objective of this study was to determine survival at two burial depths in undisturbed soil and predation rates of A. cristata seeds in soyabean crops in different rotations and tillage systems. Survival was discontinuous and decreased to 25% after 35 months, after which no further reduction in survival was observed to the end of the experiment at 96 months. No differences in seed survival between seeds placed on the soil surface and buried 5 cm below the soil surface were found at 80 months, but at later times survival was lower for seeds placed on the soil surface. Predation rates ranged between 0.3% day⁻¹ and 6.7% day⁻¹. Of the models tested, a polynomial regression of the rate of predation with time gave the best representation of seed predation. From January to July, predation was higher in non-tillage plots in the wheat/soyabean rotation. There was no significant difference in predation rates between tillage systems in the soyabean monoculture and no difference between planting densities. Higher crop residue levels in non-tillage plots in the wheat/soyabean rotation was the dominant factor influencing seed predation, probably because such habitat favours the presence of seed predators.     

P‐20 Clinical,cytopathological and histopathological evaluation of sporotrichosis in experimentally infected cats

The purpose of this study was to evaluate the clinicopathological aspects of experimental sporotrichosis in cats and compare the sensitivity of cytopathology, histopathology and culture as diagnostic tools in different phases of the infection. Twenty adult, mixed‐breed cats (10 males and 10 females) were inoculated subcutaneously with 10⁶ fungal microorganisms. Clinical examination was performed weekly. Cytopathologic, histopathologic and culture examinations were performed at 15, 30 and 60 days postinoculation. Culture of multiple organs was performed after euthanasia at 30 (10 cats) and 60 (10 cats) days postinoculation. Friedman parametric and nonparametric statistical analysis were applied to the results. The nodular, tumoral and necrotic lesionsprogressed significantly until day 30 postinoculation, and partial spontaneous regression occurred at day 60, particularly in males. An intense inflammatory pyogranulatomous and lymphocytic infiltrate with rare giant cells and sparse fibrosis associated with numerous, pleomorphic, intra‐ and extracellular fungal cells were observed on day 30. These findings gradually decreased by day 60. Despite the inflammatory granuloma associated with feline sporotrichosis, a tendency for dissemination was observed, with fungal isolation in the lymph nodes, spleen and liver at the 30 and 60 days postinoculation. No significant differences were observed between cytopathology, histopathology and fungal culture during the different phases of the disease. Therefore, cytological examination was considered a simple, rapid and inexpensive diagnostic method at all stages of this disease. Funding: Self‐funded.     

Localization of extracellular matrix receptors in ICGN mice, a strain of mice with hereditary nephrotic syndrome.

Fibrotic degeneration was examined in the kidneys of ICR-derived glomerulonephritis (ICGN) mice, a novel inbred mouse line with a hereditary nephrotic syndrome of unknown etiology considered to be a good model of human idiopathic nephrotic syndrome. In the present study, we histochemically revealed changes in accumulation of extracellular matrix (ECM) components and in localization of integrins, cellular receptors for ECM, in the kidneys of ICGN mice with the progression of renal failure. Excessive accumulation of basement membrane (laminin and collagen IV) and interstitial (type III collagen) ECM components were demonstrated in the glomeruli and tubulointerstitum of ICGN mice. Marked deposition of type I collagen and tenascin was seen only in the glomeruli of ICGN mice but not in those of ICR mice as normal controls. Increased expression of integrin alpha1-, alpha2-, alpha5- and beta1-subunits in glomeruli with fibrotic degeneration and abnormal distribution of alpha6-subunit were noted in the kidneys of ICGN mice. Excessive laminin, a ligand of alpha6beta1-integrin, was demonstrated on the tubular basement membrane, but alpha6-subunit diffusely disappeared on the basal side of the tubular epithelial cells. We presumed that abnormal integrin expression in renal tubules causes epithelial cell detachment, and consequently tubular nephropathy, and results in disorder of ECM metabolism causing excessive accumulation of ECM components in the kidneys of ICGN mice.     

Evaluation of an autogenous Salmonella bacterin and a modified live Salmonella serotype Choleraesuis vaccine on a commercial dairy farm.

OBJECTIVE: To compare the efficacy of a Salmonella bacterin and a modified live Salmonella ser. Choleraesuis vaccine on a commercial dairy. ANIMALS: 450 cows in late gestation and 80 calves. PROCEDURE: Group-1 cows (n = 150) were vaccinated once with a modified live S. Choleraesuis (serogroup C1) strain 54 (SC54) vaccine, group-2 cows (150) were vaccinated on enrollment and 30 days later with a Salmonella ser. Montevideo (serogroup C1) bacterin, and group-3 cows (150) served as unvaccinated controls. One gallon of colostrum harvested from the first 80 cows to calve was fed to each calf. Outcome assessments included fecal shedding of Salmonella spp for the first 10 days after parturition (cows) or birth (calves), milk production, involuntary culling rate, mastitis incidence, antimicrobial use, and mortality rate. RESULTS: Salmonellae were isolated from 306 of 309 (99%) cows and 64 of 74 (86.5%) calves. Shedding frequency was less in SC54-vaccinated cows and calves that received colostrum from those cows, compared with the other groups, and vaccination was specifically associated with less shedding of serogroup C1 salmonellae. Production data were similar among groups. CONCLUSIONS AND CLINICAL RELEVANCE: Vaccination of pregnant cows with an autogenous Salmonella bacterin had no effect on fecal shedding of salmonellae, whereas vaccination with a modified live S. Choleraesuis vaccine reduced the frequency of fecal shedding of serogroup C1 salmonellae during the peripartum period. A commercial S. Choleraesuis vaccine licensed for use in swine may be more efficacious than autogenous Salmonella bacterins on dairies infected with serogroup C1 salmonellae.     

Risk factors for pet evacuation failure after a slow-onset disaster.

OBJECTIVE: To determine risk factors for pet evacuation failure during a flood. DESIGN: Cross-sectional survey. SAMPLE POPULATION: 203 pet-owning households in a flooded region. PROCEDURES: Persons under evacuation notice because of a flood were interviewed by use of a random telephone survey. RESULTS: 102 households evacuated with their pets, whereas 101 households evacuated without their pets. Low pet attachment and commitment scores were significantly associated with a greater chance of pet evacuation failure. Risk of pet evacuation failure and lower attachment and commitment scores were also associated with pet management practices prior to the disaster, such as dogs being kept outdoors most of the time or owners not having carriers for their cats. More than 90% of owners made housing arrangements for their pets without assistance. CONCLUSIONS AND CLINICAL RELEVANCE: Predictors of pet evacuation failure are usually present before a disaster strikes and are potentially modifiable. Mitigation of pet evacuation failure should focus on activities that reinforce responsible pet ownership and strengthen the human-animal bond, including socializing dogs, attending dog behavior training classes, transporting cats in nondisaster times, and seeking regular preventive veterinary care. Most pet owners are self-reliant in disasters, and this behavior should be encouraged.