Treatment of Forelimb Growth Plate Deformity in 11 Dogs by Radial Dome Osteotomy and External Coaptation

Radial dome osteotomy and external coaptation were used to correct forelimb growth deformities with carpal valgus angles of 15 to 43 degrees in 11 dogs (12 forelimbs). Osteotomy sites were clinically healed by week 4. Appearance and function in 10 limbs was good to excellent. The angular deformity recurred in one dog by week 4 due to partial closure of the distal radial growth plate. Carpal valgus recurred in one dog by week 2 because the ulnar osteotomy healed before radial growth ceased.     

Effect of Tamoxifen Citrate on Canine Immobilization (Disuse) Osteoporosis

The effect of tamoxifen citrate on bone mass in immobilization osteoporosis was studied in 11 growing dogs. Immobilization osteoporosis was induced by fiberglass cast immobilization of the right hindlimb for 28 days, while the left hindlimb served as a nonimmobilized control. Six dogs received tamoxifen citrate (1.5 mg/kg per os) once daily for 28 days; five dogs received no treatment. All dogs were euthanatized on day 28 and bone samples were collected. Bone mineral content of the distal tibial metaphysis of casted and uncasted limbs was measured by single photon absorptiometry. Immobilization resulted in a significant reduction in bone mass in the casted limb of untreated and tamoxifen-treated dogs. However, tamoxifen-treated dogs had less severe immobilization osteoporosis than untreated dogs. The calculated bone mass sparing effect of tamoxifen was 24.4%. Because of the complexity of pathologic bone remodeling, use of a single therapeutic agent may not be the optimal means of preventing bone loss associated with immobilization.     

Closed System Delivery of Halothane and Isoflurane with a Vaporizer in the Anesthetic Circle

Forty-four healthy dogs undergoing elective ovariohysterectomy were anesthetized with halothane or isoflurane delivered with an in-circuit vaporizer with closed system flow rates or an out-of-circuit vaporizer with semi-closed system flow rates. When dogs were anesthetized with halothane, there were no differences in heart rate, blood pressure, body temperature, respiratory rate, or lingual venous pH, PCO2, or PO2 during induction and maintenance. Lingual venous PO2 was significantly less but still within a clinically acceptable range when isoflurane was used in an in-circuit vaporizer. Recovery times tended to be longer with in-circuit vaporizers. The amount of anesthetic used was not affected by vaporizer location. In-circuit vaporizers were suitable for delivery of halothane or isoflurane to healthy dogs.     

Use of Ultrasound In Horses for Diagnosis of Left Dorsal Displacement of the Large Colon and Monitoring its Nonsurgical Correction

During a 28 month period, 82 horses with clinical signs of abdominal pain were examined for left dorsal displacement of the large colon (LDDLC) using percutaneous ultrasound. Left dorsal displacement of the large colon was diagnosed when a gas echo dorsal to the spleen obliterated the dorsal splenic border, or when the colon was observed lateral to the spleen. In 42 horses, ultrasound confirmed a diagnosis of LDDLC and 40 horses had no evidence of LDDLC. There were five false negative results and no false positives. In four horses with LDDLC, the colon was displaced between the spleen and body wall; three of these colic episodes resolved with medical therapy and the fourth required a celiotomy to relieve a sand impaction. The remaining 38 horses had a renosplenic entrapment; surgical correction was elected in 4 horses, 21 horses were corrected by a nonsurgical rolling procedure, 12 were corrected at surgery after an unsuccessful rolling attempt, and one was corrected by rolling but required surgery later because of an additional lesion. Percutaneous abdominal ultrasound was a valuable aid in the diagnosis of LDDLC and in confirming correction of the displacement after a nonsurgical rolling procedure.     

Effects of Neodymium:Yttnum Aluminum Garnet Laser Irradiation on Endometrium and on Endometrial Cysts in Six Mares

Effects of neodymium:yttrium aluminum garnet (Nd:YAG) laser irradiation on equine endometrium were evaluated In vitro and in six mares with endometrial cysts. The Nd:YAG laser was applied to six endometrial sites, in each of five uterine specimens, with power densities of 5659 to 33,954 J/cm². Depth of tissue ablation was measured and graded on histologic sections of the tissue lesions. Power density had a significant effect on the depth of tissue ablation (p < .001). Grade 3 lesions (full-thickness ablation of the endometrium) were created with energy densities of 16,977 to 33,954 J/cm². Six mares had endometrial cysts treated by photoablation. Two of the four mares that were reproductively sound but barren, despite appropriate breeding, produced foals after treatment. One mare remained reproductively unsound after treatment, and another mare that was treated postpartum was bred successfully.