Influence of environmental humidity and dietary protein on pyramidal growth of carapaces in African spurred tortoises (Geochelone sulcata)

The carapaces of captive-raised tortoises (terrestrial chelonians of the zoological family Testudinidae, often develop pyramidal-shaped osseous growth centrally within the horny plates. With very few exceptions (e.g. Geochelone elegans, Psammobates sp.), this conical growth pattern is considered to be pathologic. This very common defect is believed to be an important indicator of the quality of captive tortoise management. This study was designed to examine the effect of dietary protein level and environmental humidity on the degree of pyramidal growth in the carapaces. Fifty recently hatched African spurred tortoises (G. sulcata) were raised for 5 months under artificial conditions of varying environmental humidity and dietary protein content (14% vs. 19% vs. 30% crude protein in dry matter). Humps of the carapaces that developed and blood values of calcium, phosphorus and haematocrit were measured and compared among groups. Dry environmental conditions (24.3-57.8% and 30.6-74.8% relative humidity) produced taller humps than humid conditions (45-99% relative humidity). Hump formation differed significantly (p < or = 0.001) between these three groups kept under different humidity conditions. Variable dietary protein had a minor, positive impact on this pathological formation of humps (pyramidal growth syndrome, PGS). Analysis of blood (calcium, phosphorus and haematocrit) offered no further explanation as to the development of the humps.     

Detection of synovial macrophages in the joint capsule of dogs with naturally occurring rupture of the cranial cruciate ligament

OBJECTIVE: To test the hypotheses that the densities of macrophages in the synovial membranes and capsules of stifle joints in dogs with ruptured cranial cruciate ligaments are greater than those of normal joints and that those densities in affected joints are positively correlated with the chronicity and severity of the disease. ANIMALS: 17 dogs with naturally occurring rupture of the cranial cruciate ligament and 5 healthy control dogs. PROCEDURE: All dogs underwent orthopedic and radiographic evaluations. In affected dogs, duration of clinical signs was used as an indicator of disease chronicity and the severity of osteoarthritis in the stifle joint was determined radiographically. Joint capsule specimens were evaluated histologically; macrophages, interleukin-6, and tumor necrosis factor-alpha were identified by use of immunocytochemical techniques. RESULTS: Compared with unaffected joints, macrophage density was increased in all affected joints. Duration of disease was significantly associated with radiographic severity of osteoarthritis and synovial macrophage density. Synovial macrophage density was significantly associated with severity of osteoarthritis and with the presence of interleukin-6 and tumor necrosis factor-a. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that synovial macrophages may be involved in the development of pathologic changes (including osteophyte formation) in the stifle joints of dogs with osteoarthritis secondary to rupture of the cranial cruciate ligament. Determination of the importance of synovial macrophages in the development of changes in osteoarthritic joints may result in new treatment strategies that involve elimination of the deleterious effects of those cells.     

Use of bovine single nucleotide polymorphism markers to verify sample tracking in beef processing

OBJECTIVE: To determine whether a selected set of 20 single nucleotide polymorphism (SNP) markers derived from beef cattle populations can be used to verify sample tracking in a commercial slaughter facility that processes primarily market (ie, culled) dairy cows. DESIGN: Prospective, blinded validation study. ANIMALS: 165 cows and 3 bulls from 18 states (82% Holstein, 8% other dairy breeds, and 10% beef breeds). PROCEDURE: Blood was collected by venipuncture from randomly chosen animals just prior to slaughter. The purported corresponding liver samples were collected during beef processing, and genotype profiles were obtained for each sample. RESULTS: On the basis of SNP allele frequencies in these cattle, the mean probability that 2 randomly selected individuals would possess identical genotypes at all 20 loci was 4.3 x 10(-8). Thus, the chance of a coincidental genotype match between 2 animals was 1 in 23 million. Genotype profiles confirmed appropriate matching for 152 of the 168 (90.5%) purported blood-liver sample pairs and revealed mismatching for 16 (9.5%) pairs. For the 16 mismatched sample pairs, 33% to 76% of the 20 SNP genotypes did not match (mean, 52%). Discordance that could be attributed to genotyping error was estimated to be < 1% on the basis of results for split samples. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that this selected set of 20 bovine SNP markers is sufficiently informative to verify accuracy of sample tracking in slaughter plants that process beef or dairy cattle. These or similar SNP markers may facilitate high-throughput, DNA-based, traceback programs designed to detect drug residues in tissues, control of animal diseases, and enhance food safety.     

Corynebacterium urealyticum urinary tract infection in dogs and cats: 7 cases (1996-2003)

OBJECTIVE: To identify clinical features of Corynebacterium urealyticum urinary tract infection in dogs and cats and antimicrobial susceptibility patterns of C urealyticum isolates. DESIGN: Retrospective study. ANIMALS: 5 dogs and 2 cats. PROCEDURE: Medical records of dogs and cats for which C urealyticum was isolated from urine samples were reviewed. Isolates from clinical cases, along with previously lyophilized unsubtyped isolates of Corynebacterium spp collected between 1977 and 1995, were examined and, if subtyped as C urealyticum, tested for antimicrobial susceptibility. RESULTS: Signalment of infected animals was variable. Prior micturition disorders were common, and all animals had signs of lower urinary tract disease at the time C urealyticum infection was diagnosed. Median urine pH was 8.0; WBCs and bacteria were variably seen in urine sediment. In vitro antimicrobial susceptibility testing of 14 C urealyticum isolates revealed that all were susceptible or had intermediate susceptibility to chloramphenicol, tetracycline, and vancomycin and most were susceptible to enrofloxacin. Thickening of the bladder wall and accumulation of sediment were common ultrasonographic findings. Contrast radiography or cystoscopy revealed findings consistent with encrusting cystitis in 3 dogs. Infection resolved in 2 dogs following surgical debridement of bladder plaques and antimicrobial administration. In 2 other dogs and 1 cat treated with antimicrobials, infection with C urealyticum resolved, but urinary tract infection with a different bacterial species developed. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that preexisting urinary tract disorders are common in dogs and cats with C urealyticum infection. Treatment with appropriate antimicrobials in combination with surgical debridement might eliminate C urealyticum infection.     

Bovine familial convulsions and ataxia in Saskatchewan and Alberta

Bovine familial convulsion and ataxia, a heritable disorder, is present in crossbred Aberdeen Angus cattle in western Canada. Though the prevalence appears to be low, this genetic defect might become widespread if not controlled. Characteristic histological lesions were seen in the lingula, uvula, or both, of all affected calves regardless of their age.     

Clinical signs, clinicopathological findings, etiology, and outcome associated with hemoptysis in dogs: 36 cases (1990-1999)

Hemoptysis, the expectoration of blood or bloody mucus from the respiratory tract at or below the larynx, was retrospectively evaluated in 36 dogs. Cough, tachypnea, and dyspnea were common historical and physical examination signs. Anemia was documented in 11 dogs, but was severe in only one dog. Other clinicopathological findings reflected the underlying diseases. All thoracic radiographs obtained were abnormal; alveolar and interstitial patterns were most common. Diseases predisposing to hemoptysis included bacterial bronchopneumonia (n=7), neoplasia (n=5), trauma (n=5), immune-mediated thrombocytopenia (n=4), heartworm disease (n=4), rodenticide poisoning (n=3), lung-lobe torsion (n=1), left-sided congestive heart failure (n=1), pulmonary hypertension (n=1), and foreign-body pneumonia (n=1). Four additional dogs had more than one underlying disease process. Nine dogs were either euthanized or died in the hospital during the initial visit. While at least half of the 27 dogs discharged went on to completely recover, five dogs discharged were known to have either died or been euthanized as a result of their disease in <6 months.     

Evaluation of the renal effects of experimental feeding of melamine and cyanuric acid to fish and pigs

OBJECTIVE: To determine whether renal crystals can be experimentally induced in animals fed melamine or the related triazine compound cyanuric acid, separately or in combination, and to compare experimentally induced crystals with those from a cat with triazine-related renal failure. ANIMALS: 75 fish (21 tilapia, 24 rainbow trout, 15 channel catfish, and 15 Atlantic salmon), 4 pigs, and 1 cat that was euthanatized because of renal failure. PROCEDURES: Fish and pigs were fed a target dosage of melamine (400 mg/kg), cyanuric acid (400 mg/kg), or melamine and cyanuric acid (400 mg of each compound/kg) daily for 3 days and were euthanatized 1, 3, 6, 10, or 14 days after administration ceased. Fresh, frozen, and formalin-fixed kidneys were examined for crystals. Edible tissues were collected for residue analysis. Crystals were examined for composition via Raman spectroscopy and hydrophilic-interaction liquid chromatography-tandem mass spectrometry. RESULTS: All animals fed the combination of melamine and cyanuric acid developed goldbrown renal crystals arranged in radial spheres (spherulites), similar to those detected in the cat. Spectral analyses of crystals from the cat, pigs, and fish were consistent with melamine-cyanurate complex crystals. Melamine and cyanuric acid residues were identified in edible tissues of fish. CONCLUSIONS AND CLINICAL RELEVANCE: Although melamine and cyanuric acid appeared to have low toxicity when administered separately, they induced extensive renal crystal formation when administered together. The subsequent renal failure may be similar to acute uric acid nephropathy in humans, in which crystal spherulites obstruct renal tubules.     

A machine vision platform for measuring imbibition of maize kernels: quantification of genetic effects and correlations with germination

Background

Imbibition (uptake of water by a dry seed) initiates the germination process. An automated method for quantifying imbibition would enable research on the genetic elements that influence the underlying hydraulic and biochemical processes. In the case of crop research, a high throughput imbibition assay could be used to investigate seed quality topics or to improve yield by selecting varieties with superior germination characteristics.

Results

An electronic force transducer measured imbibition of single maize kernels with very high resolution but low throughput. An image analysis method was devised to achieve high throughput and sufficient resolution. A transparent fixture held 90 maize kernels in contact with water on the imaging window of a flatbed document scanner that produced an image of the kernels automatically every 10 min for 22 h. Custom image analysis software measured the area A of each indexed kernel in each image to produce imbibition time courses. The ultimate change in area (ΔA) ranged from 19.3 to 23.4% in a population of 72 hybrids derived from 9 inbred parents. Kernel area as a function of time was fit well by \(A\left( t \right) = A_{f} \left( {1 - e^{ - kt} } \right)\) where A_f is the final kernel area. The swelling coefficient, k, ranged from 0.098 to 0.159 h^?1 across the genotypes. The full diallel structure of the population enabled maternal genotype effects to be assessed. In a separate experiment, measurements of kernels of the same 25 inbreds produced in three different years demonstrated that production and storage variables affected imbibition much less than genotype. In a third experiment, measurements of 30 diverse inbred lines showed that k varied inversely with germination time (r?=???0.7) and directly with germination percentage (r?=?0.7).

Conclusions

Nonspecialized imaging hardware and custom analysis software running on public cyber infrastructure form a low-cost platform for measuring seed imbibition with high resolution and throughput. We measured imbibition of thousands of kernels to determine that genotype influenced imbibition of maize kernels much more than seed production and storage environments. In some hybrids, k depended on which inbred parent was maternal. Quantitative relationships between k and germination traits were discovered.