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- Author or Editor: Dennis F. Lawler x
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Abstract
Objective—To determine prevalence of radiographic evidence of osteoarthritis in 4 diarthrodial joints of dogs with restricted feed intake, compared with dogs without restricted feed intake.
Design—Paired feeding study.
Animals—48 Labrador Retrievers.
Procedure—Dogs in litters from 7 dams and 2 sires were paired by sex and weight within litters and randomly assigned to a control-fed group or a limit-fed group that received 25% less food than the controlfed group. Radiographic evaluation of prevalence and severity of osteoarthritis in the hip, shoulder, elbow, and stifle joints was performed when dogs were 8 years of age.
Results—Radiographic evidence of osteoarthritis that affected multiple joints was significantly more common in the control-fed group than in the limit-fed group. Prevalence of lesions in the hip joint was 15/22 in the control-fed group and 3/21 in the limit-fed group. Prevalence of lesions in the shoulder joint was 19/22 in the control-fed group and 12/21 in the limitfed group; lesions in this joint were generally mild. Severity, but not prevalence, of osteoarthritis in the elbow joint was greater in the control-fed group than in the limit-fed group.
Conclusions and Clinical Relevance—Prevalence and severity of osteoarthritis in several joints was less in dogs with long-term reduced food intake, compared with control dogs. Food intake is an environmental factor that may have a profound effect on development of osteoarthritis in dogs. (J Am Vet Med Assoc 2000;217:1678–1680)
Abstract
Objective—To describe effects of lifetime food restriction on causes of death and the association between body-mass characteristics and time of death in dogs.
Design—Paired-feeding study.
Animals—48 dogs from 7 litters.
Procedures—Dogs were paired, and 1 dog in each pair was fed 25% less food than its pair mate from 8 weeks of age until death. Numerous morphometric and physiologic measures were obtained at various intervals throughout life. Associations of feeding group to time and causes of death were evaluated, along with important associated factors such as body composition components and insulin-glucose responses.
Results—Median life span was significantly longer for the group that was fed 25% less food, whereas causes of death were generally similar between the 2 feeding groups. High body-fat mass and declining lean mass significantly predicted death 1 year prior to death, and lean body composition was associated with metabolic responses that appeared to be integrally involved in health and longevity.
Conclusions and Clinical Relevance—Results were similar to results of diet restriction studies in rodents and primates, reflecting delayed death from species- and strain-specific intrinsic causes. Clinicians should be aware that unplanned body mass changes during mid- and later life of dogs may indicate the need for thorough clinical evaluation. (J Am Vet Med Assoc 2005;226:225–231)
Abstract
Objective—To determine the relationship between the caudolateral curvilinear osteophyte (CCO) and osteoarthritis associated with hip dysplasia in dogs.
Design—Longitudinal cohort study.
Animals—48 Labrador Retrievers from 7 litters.
Procedure—In each of 24 sex- and size-matched pairs fed the same diet, a restricted-fed dog was fed 25% less than a control dog for life. The dogs' hips were evaluated in the standard ventrodorsal hip-extended radiographic projection at 16, 30, and 52 weeks of age and then yearly for life. Histologic examination of hip joint tissues was performed on 45 dogs.
Results—Median age at death was 11.2 years. Adjusting for feeding group, dogs with a CCO were 3.7 times as likely to develop radiographic signs of osteoarthritis than those without a CCO. Stratified by diet, 100% of the control dogs with a CCO developed radiographic signs of osteoarthritis and 55% of restricted-fed dogs with a CCO developed radiographic signs of osteoarthritis. The CCO was the first radiographic change seen in 22 of 29 (76%) dogs with osteoarthritis. Overall, 35 of 37 (95%) dogs with a CCO had histopathologic lesions of osteoarthritis.
Conclusions and Clinical Relevance—Results indicate a relationship between a CCO on the femoral neck and subsequent development of radiographic signs of osteoarthritis in Labrador Retrievers evaluated over their life span. A CCO is an important early radiographic indication of osteoarthritis associated with canine hip dysplasia. (J Am Vet Med Assoc 2004;225:233–237)
Abstract
Objective—To evaluate the effects of diet restriction on development of radiographic evidence of hip joint osteoarthritis in dogs.
Design—Longitudinal cohort study.
Animals—48 Labrador Retrievers from 7 litters.
Procedures—Forty-eight 6-week-old puppies from 7 litters were paired with littermates by sex and weight, and each pairmate was randomly assigned to 1 of 2 groups of 24 dogs each. Starting at 8 weeks of age, 1 group was fed ad libitum (control fed) and the other was fed 25% less (restricted fed) of the same diet for life on a pairwise basis. The dogs' hip joints were radiographed in the standard ventrodorsal hip-extended view at multiple intervals prior to 1 year of age and at annual intervals thereafter on the basis of birth anniversary. A board-certified radiologist unaware of group assignment scored the radiographs for evidence of osteoarthritis.
Results—Prevalence of radiographic evidence of hip joint osteoarthritis in all dogs increased linearly throughout the study, from an overall prevalence of 15% at 2 years to 67% by 14 years. Restricted-fed dogs had lower prevalence and later onset of hip joint osteoarthritis. Median age at first identification of radiographic evidence of hip joint osteoarthritis was significantly lower in the control-fed group (6 years), compared with the restricted-fed group (12 years).
Conclusions and Clinical Relevance—Restricted feeding delayed or prevented development of radiographic signs of hip joint osteoarthritis in this cohort of Labrador Retrievers. Lifetime maintenance of 25% diet restriction delayed onset and reduced severity of hip joint osteoarthritis, thus favorably affecting both duration and quality of life. In addition, the data indicated that development of hip joint osteoarthritis was not bimodal in these dogs but occurred as a continuum throughout life.
Abstract
Objective—To determine the relationship between a circumferential femoral head osteophyte (CFHO) and osteoarthritis characteristic of canine hip dysplasia, and to ascertain whether CFHO, like osteoarthritis, varies between diet-restricted and control-fed dogs.
Design—Longitudinal cohort study.
Animals—48 Labrador Retrievers.
Procedures—Dogs were paired by size, sex, and litter and assigned to 1 of 2 equal groups at 2 months of age. The control-fed group was fed ad libitum, and the diet-restricted group was fed 25% less on a pairwise basis of the same diet for life. The dogs' hip joints were radiographed yearly for life. Each radiograph was evaluated for radiographic signs of osteoarthritis characteristic of hip dysplasia and for the presence and severity of a CFHO.
Results—41 of the 48 (85.4%) dogs had a CFHO, which was detected at a median age of 5.4 years, and 33 of those 41 (80.5%) developed radiographic evidence of osteoarthritis. Nineteen (79.2%) dogs in the diet-restricted group and 22 (91.7%) in the control-fed group had a CFHO at a median age of 9 and 3 years, respectively. Of the dogs with a CFHO, 12 (63.2%) in the diet-restricted group and 20 (90.0%) in the control-fed group developed radiographic evidence of osteoarthritis characteristic of hip dysplasia at a median age of 11 and 6.5 years, respectively.
Conclusions and Clinical Relevance—Results indicated a relationship between the CFHO and subsequent development of radiographic signs of osteoarthritis. If a CFHO is present in Labrador Retrievers, it might be considered an early indicator of osteoarthritis.
Abstract
Objective—To evaluate the effects of 25% diet restriction on life span of dogs and on markers of aging.
Design—Paired feeding study.
Animals—48 Labrador Retrievers.
Procedures—Dogs were paired, and 1 dog in each pair was fed 25% less food than its pair-mate from 8 weeks of age until death. Serum biochemical analyses were performed, body condition was scored, and body composition was measured annually until 12 years of age. Age at onset of chronic disease and median (age when 50% of the dogs were deceased) and maximum (age when 90% of the dogs were deceased) life spans were evaluated.
Results—Compared with control dogs, food-restricted dogs weighed less and had lower body fat content and lower serum triglycerides, triiodothyronine, insulin, and glucose concentrations. Median life span was significantly longer for dogs in which food was restricted. The onset of clinical signs of chronic disease generally was delayed for food-restricted dogs.
Conclusions and Clinical Relevance—Results suggest that 25% restriction in food intake increased median life span and delayed the onset of signs of chronic disease in these dogs. (J Am Vet Med Assoc 2002;220:1315–1320)