Molecular identification of bacteria associated with canine periodontal disease

Hsp90 is a molecular chaperone that is involved in diverse cellular processes including protein folding/repairing and signal transduction. Edwardsiella tarda is a serious fish pathogen that affects fish aquaculture worldwide. The aim of this study was to investigate the potential importance of HtpG, the prokaryotic homologue of Hsp90, in the pathogenesis of E. tarda. E. tarda HtpG is 627-residue in length and contains domain structures that are conserved among Hsp90 family members. Quantitative real time RT-PCR analysis indicated that expression of htpG is induced by heat shock and oxidative stress. Recombinant HtpG (rHtpG) purified from Escherichia coli exhibits apparent ATPase activity, which is optimal at 40°C. Mutation of htpG (i) affects bacterial growth at elevated temperature and renders the cells more sensitive to stress induced by reactive oxygen species, (ii) causes dramatic reduction in blood dissemination and general bacterial virulence, (iii) weakens the ability of E. tarda to block head kidney macrophage activation and to resist against the bactericidal effect of macrophages, and (iv) upregulates the expression of pro-inflammatory cytokines in macrophages. Taken together, these results indicate that HtpG is a biologically active protein that is required for E. tarda to cope with various stress conditions especially that encountered in vivo the host system during infection.     

Osteosarcoma associated with healed fractures

Two cases of osteosarcoma development associated with previous long bone fractures are described. In one case the surgical implant used was still in place. Other cases reported in the literature are reviewed.     

The owner-animal-environment triad in the treatment of canine periodontal disease

In a perfect world, all veterinarians and veterinary dental technicians would understand periodontal disease as well as the dental specialist. They would all be able to recognize the early signs of periodontal disease and recommend treatment to prevent its progression. The owners would have the financial resources, time, and desire to maintain their pet's oral health. The dogs would all be calm and compliant with home care and have no particular anesthetic risks. Unfortunately, this is not a perfect world. Some veterinarians do not understand periodontal disease any better that I understand cosmic string theory. Some owners have limited financial resources and are not particularly committed to their pet's oral health. Some animals will not tolerate any type or manner of home care. Given that animals, their mouths, and their owners come in an infinite variety of shapes and sizes (figuratively and literally), how can we talk about the treatment of periodontal disease as if it is a single condition with a single treatment, or even only a few treatment options? Each owner, animal, and its environment must be assessed on an individual basis to develop a treatment plan that is reasonable and attainable based on the unique circumstances of each case. So, what should be the goal when treating periodontal disease? Is it the preservation of all teeth at all costs? Is it the preservation of important teeth if the costs can be kept reasonable? I would suggest that the overriding goal of periodontal treatment should be the elimination and prevention of oral infection and oral pain. In the domestic environment, dogs have no real need to defend territory. They have no need to prehend and kill live prey animals. In short, the domesticated pet dog does not need teeth at all. This may seem like an odd statement for a veterinary dentist to make, but I feel quite strongly that a dog is far better off having no teeth than having bad teeth. My preference is that a dog should have a full set of healthy, functional teeth, but preserving bad teeth in the face of a poor or questionable prognosis serves no positive purpose.     

Feline porphyria associated with anemia, severe hepatic disease, and renal calculi

A 13-year-old, neutered male domestic cat presented with signs of weight loss, anemia, and hepatomegaly. Pathognomonic signs of porphyria were identified. Charcoal-like renal calculi and severe liver changes were observed, neither of which has been previously reported in association with feline porphyria.     

Topical treatment of digital dermatitis associated with severe heel-horn erosion in a Swedish dairy herd

Two experiments were run in a commercial dairy herd to test the efficacy of topical treatments of digital dermatitis associated with severe heel-horn erosion. In Experiment I, topical treatments with solutions of either glutaraldehyde or oxytetracycline were compared with foot trimming and cleansing alone. After trimming of all feet, one front and one rear foot in each cow were treated with either glutaraldehyde or oxytetracycline (regardless of dermatitis status), while the other feet were used as controls and only trimmed. Two hundred foot records were obtained from 34 Swedish Red and White and 16 Swedish Holstein cows. The proportions (p) of feet cured from digital dermatitis were compared between each group of medically treated feet and the control feet, assuming the feet to be independent observations with respect to curing. Oxytetracycline was significantly more effective than hoof trimming alone (p=0.87 and 0.34, respectively; P<0.001) and than glutaraldehyde (p=0.41; P=0.004). Treatment with glutaraldehyde was no more effective than hoof trimming alone.In Experiment II, a specially designed footbath with two longitudinal compartments was used to study the effectiveness of a solution of acidic ionised copper in preventing or curing digital dermatitis. The footbath--using water in one compartment--was constructed to make within-cow comparisons of treatment efficacy possible. The hoof health of 44 dairy cows (also included in Experiment I) were studied when the animals first were turned out to pasture and at the end of the grazing season (approximately 6 months later). During the grazing season, the cows were walked through the footbath twice daily after milking for a total of 47 days, divided into five separate periods ranging in length from 3 to 16 days. As judged by a two-sample comparison of proportions, a higher proportion of the cows' hind feet that were affected by dermatitis were cured by the copper solution (20/24) than by water alone (12/23). The copper solution had no significant preventive effect on healthy feet.     

Effect of long-term intermittent periodontal care on canine periodontal disease

The periodontal health status was assessed in two groups of dogs which had received different levels of periodontal care over a two-year period. The dental group received regular dental scaling and polishing, and intermittent daily tooth brushing, while the control group received no periodontal care. All dogs developed gingivitis, and two (one from each group) showed evidence of incipient periodontitis. The dental group had a reduced gingivitis index (GI) compared with the control group only when they had received daily tooth brushing before the GI assessment. When the dogs had not had their teeth brushed for four weeks before the assessment, the GI was not significantly different to that in the control dogs. This suggests that continual periodontal care throughout life is of great importance and questions the benefits of intermittent oral care. The GI of the palatal and lingual surfaces in all dogs was significantly higher than the GI of the buccal surfaces. Thus, all tooth surfaces may need to be cleaned to achieve optimal periodontal health.     

Femur fractures associated with canine total hip replacement

OBJECTIVE: To report femur fracture as a complication of canine total hip replacement (THR) and to report the incidence, predisposing factors, treatment options, and outcome. STUDY DESIGN: Prospective clinical study. ANIMALS: Twenty-two client-owned dogs with 24 femoral fractures occurring during or after THR. METHODS: Cemented THR (BioMedtrix, Boonton, NJ) was performed. Medical records and radiographs were used to identify dogs that had femur fracture and to identify risk factors. Follow-up was obtained until dog death or study end. RESULTS: The overall incidence of femur fracture after THR was 2.9%. Femoral fractures occurred intraoperatively, immediately postoperatively, and up to 2196 days after THR. In 17 dogs, fractures resulted from a traumatic event. Osteopathy was present at THR in 5 dogs; all developed femoral fissures during reaming. Three dogs had fractures associated with cortical thinning secondary to aseptic loosening. Fracture treatment included euthanasia (1 dog), strict confinement (3 dogs), full cerclage wires on long oblique fractures (3 dogs), or plate and screw fixation (10 with, and 7 without, cerclage wires). All fractures extended near the distal tip of the femoral stem and all aggressively treated fractures healed. CONCLUSIONS: Predisposing risk factors for femur fracture after THR include osteopathy and iatrogenic fissures created during reaming. Trauma, excessive load concentration, and increased torque can lead to mid-diaphyseal fracture near the end of the femoral stem. Fracture did not disrupt THR implants. Cement fracture exposing the tip of the femoral stem did not affect fracture healing or rehabilitation. Immediate plate and screw fixation resulted in the most favorable outcome; healing occurred in 6-10 weeks. CLINICAL RELEVANCE: Femur fractures that occur after THR should be repaired using plate and screw fixation augmented with cerclage wire when needed. Forces on fissures should be neutralized to prevent propagation and fracture. Owners of high-risk patients (old dogs with osteopathies or previous hip surgery) should be counseled before THR. The prognosis is excellent when fractures are treated correctly.     

Metacarpal fractures associated with pancarpal arthrodesis in dogs

OBJECTIVE: To report the prevalence of third metacarpal bone fractures after dorsal plating for pancarpal arthrodeses in dogs and to identify predisposing factors. STUDY DESIGN: Retrospective clinical study. ANIMALS: Fifty-four client-owned dogs. METHODS: Pancarpal arthrodesis was performed using dorsally applied 2.7- or 3.5-mm bone plates. Medical records and radiographs were retrospectively evaluated to identify those dogs with metacarpal bone fractures after pancarpal arthrodesis and to determine the angle of arthrodesis, the percentage of the third metacarpal bone covered by the bone plate, and the percentage width of the bone occupied by the screw. Radiological evidence of arthrodesis at follow-up examination 6 weeks postoperatively was recorded. Long-term results were obtained by telephone follow-up with the owners. All lame dogs were evaluated clinically and radiographically. RESULTS: Metacarpal fractures occurred in 6 of 54 dogs. One of these dogs had a stress fracture of the third metacarpal 10 months after implant removal and was not included in the statistical analysis. Fractures occurred through the distal screw hole in four dogs and involved two metacarpal bones (III and IV) in two dogs. The median ratio of bone screw diameter-to-metacarpal bone diameter was the same for dogs with metacarpal bone fractures and those with no fractures (44%), and the median angles of arthrodesis were 8 degrees and 7 degrees. These values were not statistically significant. The percentage length of the metacarpal bone covered by the plate was 53% (no fracture) compared with 46% (fracture), and this difference was statistically significant (P = .035). CONCLUSIONS: Screw diameter was not implicated as a predisposing factor for metacarpal bone fracture in dogs undergoing pancarpal arthrodesis using a dorsally applied dynamic compression plate. The length of the metacarpal bone covered by the bone plate did affect the frequency of metacarpal fracture, with fewer fractures occurring when greater than 53% of the bone length was covered by the dynamic compression plate. CLINICAL RELEVANCE: When performing pancarpal arthrodesis with a dorsally applied bone plate, it is recommended that at least 50% of the length of the third metacarpal bone should be covered by the plate.     

Feline experimental models for control of periodontal disease.

Feline periodontal disease has many elements in common with human and canine disease. Anatomic, physiologic, microbiologic, and immunologic differences between the three species make it impossible to predict with certainty whether successful approaches to controlling and treating canine oral disease will also prove successful in cats. We have developed methods for reproducible, quantitative evaluation of feline dental plaque and calculus. Our studies demonstrated that feline plaque accumulation peaks at 1 week after prophylaxis and that calculus peaks at 4 weeks after prophylaxis. These methods should be adequately sensitive to document control of plaque and calculus accumulation by efficacious chemical or antimicrobial agents.     

Oral flora of mongrel and beagle dogs with periodontal disease

The plaque flora was studied in adult mongrel and beagle dogs with periodontal disease. Gingival plaque from maxillary premolars was removed and cultured on various growth media. The flora in all dogs was composed of mostly anaerobic gram negative rods. Bacteroides asaccharolyticus was found in the highest proportion of plaque samples from mongrel dogs, and decomposed hydrogen peroxide suggesting catalase activity. Fusobacterium nucleatum was found in higher proportion in the plaque of beagle dogs as compared to B. asaccharolyticus. With the increasing numbers of obligative anaerobic gram negative organisms such as B. asaccharolyticus, the proportions of Streptococcus, Enterococcus and Staphylococcus decreased in the dogs with periodontal disease. The salivary flora was different from the plaque flora of the dogs with periodontal disease. It was constant regardless with the disease. The salivary flora of beagle dogs with the healthy gingiva was different from that of mongrel dogs. Enterococcus, Lactobacillus, Eubacterium and black-pigmented Bacteroides (BPB, mainly B. asaccharolyticus) were higher proportion in the flora of beagle dogs as compared to mongrel dogs, while Fusobacterium, Enterobacteriaceae, yeast and molds were lower in the flora. The results reveal that B. asaccharolyticus and F. nucleatum are common pathogens and uniquely contribute to the development of gingival inflammation in dog.     

Feedlot health and performance effects associated with the timing of respiratory disease treatment

Generalized linear mixed models were developed using retrospective feedlot data collected on individually treated cattle (n = 31,131) to determine whether cattle performance and health outcomes in feedlot cattle were associated with timing of treatment for bovine respiratory disease (BRD) during the feeding phase. Cattle that died at any point during the feeding phase were removed from the analysis. Information on individual animal performance (ADG, HCW, quality grade, yield grade) and health outcomes (treatments) were incorporated into an economic model that generated a standardized net return estimate for each animal. Prices were standardized to minimize variation between economic outcomes due to market conditions allowing direct comparisons of health and performance effects between animals. While controlling for sex, risk code, and arrival BW class, potential associations between net returns and the timing of BRD identification were investigated using 2 categorical variables created to measure time: 1) weeks on feed at initial BRD treatment, and 2) weeks from BRD treatment to slaughter. The first model using net return as the outcome identified an interaction between weeks on feed at initial BRD treatment and animal arrival BW. Cattle with arrival BW between 227 and 272 kg (5WT) and 273 and 318 kg (6WT) displayed decreased net returns (P < 0.05) if treated during wk 1 as compared with subsequent weeks in the first month of the feeding phase. The cattle with BW between 319 and 363 kg (7WT) and 364 and 408 kg (8WT) exhibited decreased net returns (P < 0.05) if treated during the later weeks of the feeding phase compared with earlier in the feeding phase. The number of times cattle were treated contributed to variation in net returns for the 5WT and 6WT cattle. For the 7WT and 8WT cattle, HCW was the main factor contributing to decreased net returns when cattle were treated late in the feeding phase. The second model identified an interaction between weeks from BRD treatment to slaughter and arrival BW. The 181 to 226 kg of BW, 5WT, 6WT, 7WT, and 8WT cattle all exhibited decreased net returns (P < 0.05) when cattle were on feed fewer weeks from BRD treatment to slaughter. Cattle with more weeks on feed between BRD treatment and slaughter had greater HCW, decreased ADG, and more total treatments compared with cattle treated closer to slaughter. This research indicates that timing of initial BRD treatment is associated with performance and health outcomes.     

Epidemiology of periodontal disease in poodles

The periodontal condition of 123 poodles was assessed using the parameters of depth of gum pocket, attachment level, bleeding on probing, and plaque and calculus accumulation. No dogs were free of periodontal disease. The number of deep pockets and dramatic loss of attachment ranged from 0.1 teeth in young dogs to 4.2 teeth in old animals. A sixfold increase in deep pocketing took place in dogs between the ages of six and seven, followed by a twofold increase in the number of teeth missing in dogs within the 10 to 11 year age group. First premolars, incisors and second molars were at highest risk. No correlation between dietary conditions and disease incidence could be detected. It is concluded that, by concentrating their diagnostic efforts on those age groups and types of teeth at highest risk, clinicians could improve the effectiveness of their treatment interventions.