Objective—To compare values of lower urogenital tract urodynamic and morphometric variables determined during the prepubertal (sexually immature) period and first and second estrous cycles in healthy female Beagle littermates to determine functional and anatomic changes of the lower urogenital tract during those periods.
Animals—5 female Beagle littermates.
Procedures—Urethral pressure profilometry, diuresis cystometry, and vaginourethrography were performed when dogs were 3.5, 4.5, 5, 6, 7, 8, 8.5, and 9 months old and during proestrus; estrus; early, middle, and late diestrus; and early and late anestrus of the first and second estrous cycles.
Results—At the end of the prepubertal period, values of urodynamic and morphometric variables increased significantly, compared with values at earlier times. Maximum bladder capacity developed when dogs were 9 months old. In all dogs, the bladder was intermittently located in an intrapelvic position during the prepubertal period; the bladder was intra-abdominal from the time dogs were 9 months old until the end of the study. Urethral pressure decreased significantly during estrus and early diestrus of the first and second estrous cycles. Bladder capacity increased significantly during diestrus of both estrous cycles. Urethral and vaginal lengths were significantly longer during proestrus and estrus than they were during anestrus.
Conclusions and Clinical Relevance—Values of lower urogenital tract urodynamic and morphometric variables were influenced by age and phases of the estrous cycle of immature and young adult Beagles in this study. Age of dog and phase of estrous cycle should be considered when interpreting urodynamic and vaginourethrography data.
To describe functional and anatomic changes of the lower urogenital tract of healthy male dogs during the sexually immature period and up to 2 years of age by urodynamic and morphometric assessment.
6 sexually intact male Beagle littermates.
Dogs underwent electromyography-coupled urodynamic tests, CT-assisted retrograde urethrography, prostatic washes, and blood sampling monthly from 4 through 12 months of age and then at 3-month intervals. Urodynamic and morphometric variables and serum canine prostate–specific esterase concentrations were analyzed by statistical methods.
Integrated pressure of the urethra was significantly increased beginning at 8 months of age, compared with earlier time points. Urethral pressure peak amplitudes varied among anatomic regions. During bladder filling, few electromyographic signals were concurrent with urethral pressure peaks; these were most commonly detected in the penile portion of the urethra. Urethral length and prostate gland volume were significantly greater from 7 to 24 months of age than at younger ages. Urethral length was approximately 26 to 27 cm after 9 months, and prostate gland volume was approximately 11 to 12 cm after 11 months of age. Serum canine prostate–specific esterase concentrations correlated with prostate gland volume. Urinary bladder threshold volume was significantly increased at 6 months of age, compared with that at 4 months, with a maximum of 197.7 mL at 24 months.
CONCLUSIONS AND CLINICAL RELEVANCE
Urethral resistance was acquired at approximately 8 months of age, when growth of the lower urinary tract was incomplete. Electromyographic and integrated pressure measurement results and the distribution and amplitude of urethral pressure peaks highlighted the potential role of the prostate gland and possibly the bulbocavernosus muscles in control of continence.
Case Description—A 1.5-year-old spayed female domestic shorthair cat was admitted for hind limb locomotor difficulties and signs of pain along the lumbar portion of the vertebral column. At the time of referral, the cat was paraparetic with deficits in the spinal reflexes of the hind limbs. Neuroanatomic localization was at the L6-S2 spinal cord segments, corresponding approximately to the region of the L4-L6 vertebral bodies.
Clinical Findings—Radiography revealed a mixed osteolytic-proliferative lesion within the body of L5 involving the cranial end plate, as well as punctate radiolucencies in the distal portion of the femur. Magnetic resonance imaging revealed an intramedullary spinal cord lesion along with extensive meningeal and nerve root lesions in the area of the L4-L6 vertebral bodies. Cytologic analysis of a bone marrow aspirate from the right trochanteric fossa revealed a substantial plasma cell infiltrate. Analysis of CSF revealed a high protein concentration and morphologically abnormal plasma cells. Urine, but not serum, protein electrophoresis revealed a sharp γ-globulin peak consistent with a monoclonal band of Bence-Jones proteins. The diagnosis was multiple myeloma.
Treatment and Outcome—The cat was treated with melphalan and prednisolone. A rapid clinical response was reported, and by week 3 after diagnosis, the cat's locomotion and behavior had normalized. However, by month 4, multifocal neurologic deficits were evident. The cat was euthanized at 9 months because of tetraparesis and substantial weight loss.
Clinical Relevance—To our knowledge, this is the first report of myeloma in a cat that had electrophoretically detectable light chain proteinuria but lacked a detectable serum monoclonal gammopathy.