The pathogenesis and diagnosis of canine hip dysplasia: a review.

Hip dysplasia is a common developmental problem affecting the canine population. Despite extensive research into the condition, many questions remain unanswered and numerous misconceptions are present among the general public. The purpose of this paper is to review the current knowledge on the development of hip dysplasia, factors modifying its development, and current diagnostic techniques.A computerized literature search was conducted for the period of January 1983 to April 1985 using the MEDLINE and CAB databases, and the keywords hip dysplasia, hip, dog, and canine. Other articles,wherever possible original research articles, published before 1983 were also reviewed. Animals affected by hip dysplasia are born with normal hips, but quickly develop subluxation of the femoral head. Degenerative joint disease follows. Hip dysplasia is a complex, inherited, polygenic trait. Selective breeding of only normal dogs with normal littermates, parents, and grandparents is there commended method of reducing the incidence in the general population.Gene expression in affected individuals may be modified by a number of environmental factors. These factors do not cause hip dysplasia, but they alter manifestations of the trait and its severity. Nutrition is a major environmental factor. Excess energy consumption increases the frequency and severity of hip dysplasia in genetically predisposed dogs. Food intake should be regulated to maintain a slender figure with the ribs and dorsal vertebral spines easily palpable, but not visible. Excess dietary calcium and vitamin D contribute to hip dysplasia in genetically predisposed individuals and should be avoided. High dose vitamin C supplementation ingrowing puppies does not prevent hip dysplasia, and this practice should be discontinued. Animals must be 2 years old before they can be certified as normal, but the disease may be diagnosed earlier. Earlier diagnosis of the condition would be very useful for the selection of breeding stock, but palpation techniques and the standard extended view radiographs have unacceptably high rates of error in young puppies. Stress radiography techniques may improve the accuracy of early diagnosis in the future.

Treatment of canine hip dysplasia: a review.

This article discusses the treatment approaches and recommendations for canine hip dysplasia. A search of the literature database MEDLINE (1969-1994) was conducted and relevant journal articles regarding the medical and surgical treatment of hip dysplasia were selected and reviewed. Dysplastic dogs can be divided, for treatment purposes, into those with no or minimal osteoarthrosis, and those with moderate to severe osteoarthrosis. In young animals with joint laxity and pain, but with no or minimal radiographic evidence of osteoarthrosis, the treatment approach is controversial. Conservative management may be effective in the short term, but progressive development of osteoarthrosis occurs and clinical signs may manifest at an older age. Options for surgical treatments in these young dogs include pectineal myectomy, lengthening of the femoral neck, and corrective osteotomies. Corrective osteotomies are advocated to reestablish joint congruency and prevent development of osteoarthrosis. In the mature osteoarthritic dog, effective conservative management depends on the severity of the degenerative joint disease. Proposed surgical treatments for clinically debilitating hip dysplasia include biocompatible osteoconductive/shelf arthroplasty; femoral head and neck excision arthroplasty, with or without muscle sling interposition; and total hip replacement. Although research directly comparing the salvage procedures has not been reported, studies suggest that total hip replacement is more effective in returning large dogs to full functional weight bearing.

Injuries suffered by dogs from riding in the back of open pickup trucks: a retrospective review of seventy cases.

Case records of 70 dogs injured while riding in the back of open pickup trucks during the period January 1, 1982, to May 1, 1993, were reviewed. Most dogs were young (mean age 2.4 y) and of medium to large size (average weight 22.6 kg). Sixty-five dogs (93%) were injured during the months of April through October. Forty-nine dogs (70%) had single injuries and 21 dogs (30%) sustained multiple injuries. Fractures were the most frequent injury incurred, with fractures of the femur the most common. Surgical repair was recommended in all but 2 cases.

Medial patellar luxation in 16 large dogs. A retrospective study.

Unilateral medial patellar luxation was diagnosed in 10, and bilateral medial patellar luxation in six, large and giant-breed dogs (22 stifles). Lameness occurred in five dogs after trauma or surgery, and 11 dogs had no known predisposing history. The mean age at presentation was 25 months, and the mean time from initial onset of clinical signs to diagnosis was 13 weeks. All traumatic or iatrogenic luxations (five dogs) were unilateral. Luxations presumed to be congenital were unilateral in five dogs and bilateral in six. The grades of medial patellar luxation were I (1 stifle), II (11 stifles), III (9 stifles), and IV (1 stifle). Preoperative function was good (1 dog), fair (9 dogs), and poor (6 dogs). Surgical correction was performed in dogs with grades II, III, and IV luxations (21 stifles). Complications included one wound dehiscence and trochlear wedge migration, one pin loosening, and one persistent lameness caused by lymphoplasmacytic synovitis. Long-term follow-up was available in 13 dogs (18 stifles). Function was judged by owners to be excellent in seven dogs, good in five dogs, and poor in one dog. Surgical treatment of grades II and III luxations yielded good (8 stifles) and excellent (9 stifles) results, while one grade IV luxation had a poor long-term outcome.

Enterocystoplasty with cystectomy and subtotal intracapsular prostatectomy in the male dog.

Urinary diversion by implantation of the ureters into an isolated segment of jejunum was evaluated in eight clinically normal male dogs. Total cystectomy and subtotal intracapsular prostatectomy were performed, and the intestinal loop was sutured to the prostatic remnant. General health, renal function, acid-base balance, urinary tract infection, and urinary continence were monitored during observation periods of 4 to 30 weeks. All dogs survived the observation period and seven were in excellent general health at the time of euthanasia. Six of the 16 ureterointestinal anastomoses were complicated by complete ureteral obstruction. Absorption of urea from the intestinal loop was speculated as the reason for significant increases in serum urea nitrogen concentrations in all of the dogs. Serum creatinine concentrations generally remained within the normal range, but were significantly increased from preoperative baseline values by week 30. There was dilation of 12 renal pelves and ureters in seven dogs. Urine bacterial cultures were positive in six dogs, but histologic evidence of pyelonephritis was present in only five kidneys. Ejaculation was not affected by the procedure, but epididymitis was present in five dogs. The dogs could urinate consciously and did not dribble urine continuously; however, they urinated hourly. While the procedure was well tolerated by the dogs, the frequency of urination makes this technique unacceptable for most household pets.