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Abstract

Objective

To evaluate benign familial hyperphosphatasemia involving serum alkaline phosphatase (SAP) in pups.

Design

Pups with markedly increased SAP activity were evaluated and compared with unaffected siblings, and with other unaffected Siberian Husky pups from the same colony.

Animals

8 related litters of Siberian Husky pups (n = 56).

Procedure

At ages 11 and 16 weeks, pups were given physical examinations and blood was obtained for hematologic and serum biochemical analyses (including electrolytes and isoenzymes of alkaline phosphatase), ionized calcium concentration, and serum parathyroid hormone concentration. Diet, growth and health performance, skeletal radiographs, and genealogical data also were evaluated.

Results

Of 42 pups tested, 17 had markedly high total SAP values. Mean total SAP activity of affected pups at ages 11 and 16 weeks was over 5 times greater than mean total SAP activity of unaffected siblings and other unaffected Siberian Husky pups of the same age (P <0.001). Clinical, radiologic, and biochemical evaluation of the subjects revealed no other abnormal findings. The source of the increased SAP activity was characterized in 5 affected pups as bone isoenzyme. The mode of inheritance could not be deduced from the data, but the trait clearly is familial and autosomal.

Conclusion

The condition described in the family of Siberian Huskies bears similarity to human benign, persistent, familial hyperphosphatasemia.

Clinical Relevance

Benign familial hyperphosphatasemia should be considered in the differential diagnosis of markedly increased SAP activity in young dogs. (Am J Vet Res 1996; 57:612–617)

Free access
in American Journal of Veterinary Research

Abstract

Objective

To examine effects of restricted food intake on estrous cycle frequency, interestrus interval, and pseudopregnancy prevalence in dogs.

Animals

28 female Labrador Retrievers.

Procedure

Dogs were paired by body weight when they were 6 weeks old and fed so that the limit-fed pair-mate received 75% of the amount of food offered to its maintenance-fed counterpart. Estrous cycle, interestrus interval, and pseudopregnancy data were recorded.

Results

Mean annual frequency of estrous cycles and duration of interestrus intervals did not differ between feeding groups. Prevalence of clinically evident pseudopregnancy was significantly greater among females that were maintenance fed, although results of endocrinologic testing did not identify a mechanism for this observation.

Conclusions and Clinical Relevance

Pseudopregnancy in dogs can be influenced by physiologic factors related to nutrition. Clinicians should consider a variety of physiologic and environmental factors when evaluating reproductive function in dogs. (Am J Vet Res 1999;60:820–825)

Free access
in American Journal of Veterinary Research

Summary

Effects of increased dietary chloride and reduced sodium and potassium ion concentrations on coxofemoral joint conformation, as assessed by radiography, were examined in growing dogs. Dietary electrolyte balance was quantified by dietary anion gap (dag), defined as Na+ + K+ - Cl- in milliequivalents per 100 g of food. Diets had anion gap ranging from 8 to 41 mEq/100 g of food. One hundred sixty-seven pups from 27 litters representing 5 breeds were studied during the period of rapid growth. The extent of subluxation of the femoral head was measured on radiographs, using the method of Norberg. On average, less subluxation of the femoral head (P < 0.05) was observed when diets with lower dag were fed. Differences in dag balance did not result in different rates of weight gain; therefore, the reduction in coxofemoral joint subluxation attributable to low dag was unrelated to weight gain. Norberg angles measured at 30 weeks of age were highly correlated with coxofemoral joint status at 2 years of age, as measured by the Swedish diagnostic system and the scoring system of the Orthopedic Foundation for Animals (|r| ≥ 0.70, P < 0.0002, n = 24). This diet-related improvement in coxofemoral joint subluxation would be expected, on average, to delay or mitigate the characteristic clinical and radiographic signs of hip dysplasia in growing dogs.

Free access
in American Journal of Veterinary Research

Summary

Forty-eight 8-week-old Labrador Retrievers were allotted to 2 groups of 24 dogs each; 1 group was fed ad libitum and the other group was given 25% less of the same feed until the dogs were 2 years old. Radiography of the hip joints was done when the dogs were 30, 42, 54, 78, and 104 weeks old. Subluxation was measured by the Norberg angle on radiographs made with the dog in the standard (extended limb) position. Independent of age at which the radiography was done, there was less subluxation of the femoral heads in the limit-fed dogs. Using the Swedish method of hip joint evaluation on the same radiographs, it was found that fewer dogs on limited food intake had signs of hip dysplasia.

Radiographs done when dogs were 2 years old, for all the methods used (Norberg angle in standard and frog-limb position, the Orthopedic Foundation for Animals [ofa] score, and the Swedish score), revealed less hip dysplasia (less joint subluxation and less degenerative joint disease) in the limit-fed dogs. Using the ofa method, 7 of the 24 limit-fed dogs and 16 of the 24 ad libitum-fed dogs were diagnosed as having hip dysplasia. Similarly, using the Swedish method, 5 of the 24 limit-fed dogs and 18 of the 24 ad libitum- fed dogs were diagnosed as having hip dysplasia. The food-intake-related differences were significant both for the ofa score and for the Swedish score. There was a significant correlation between the Norberg angle measured on radiographs made with the dog in the standard position when it was 30 weeks old and the result obtained when the dog was 2 years old by the ofa and Swedish methods. The findings support the clinical recommendation to avoid overfeeding of growing dogs, particularly in breeds prone to canine hip dysplasia.

Free access
in Journal of the American Veterinary Medical Association

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)

Full access
in Journal of the American Veterinary Medical Association

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)

Full access
in Journal of the American Veterinary Medical Association

SUMMARY

Forty-four female American Shorthair cats with inflammatory uterine disease or infertility were evaluated. Data collected included age, month of diagnosis, housing, reproductive history, results of bacteriologic culture of uterine specimens, serum concentrations of estrogen, progesterone, and prolactin and histopathologic features of the ovaries and uterus.

Histologically, the ovaries of 19 cats were dominated by active or cystic follicles, whereas 25 cats had luteal-phase ovaries. Of the 25 cats with active corpora lutea, 20 had either recently weaned litters (n = 11) without subsequent exposure to a male cat, or had been housed individually for lengthy periods (n = 9). The finding of active corpora lutea under these circumstances indicates that in queens, ovulation may occur by mechanisms not involving coitus.

Prominent, active corpora lutea on the ovaries were associated with adenomatotic proliferative changes in the superficial and glandular epithelium of the uterus and with myometrial hyperplasia, compared with the uterus of cats with follicular ovaries (P < 0.01).

Serum progesterone concentration ≥ 1.87 ng/ml was consistently associated with luteal-phase ovaries. Serum progesterone values ≤ 0.15 ng/ml were consistently associated with follicular-phase ovaries.

Escherichia coli was the organism most commonly isolated from uterine contents.

Free access
in American Journal of Veterinary Research

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.

Full access
in Journal of the American Veterinary Medical Association

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)

Full access
in Journal of the American Veterinary Medical Association

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.

Full access
in Journal of the American Veterinary Medical Association