Clinical response of nasal adenocarcinoma to cisplatin chemotherapy in 11 dogs.

In 11 dogs with nasal adenocarcinoma, IV treatment with 2 to 8 cycles of cisplatin at a dosage of 60 mg/m2 of body surface, given at 3-week intervals, resulted in a survival time of 8 to 128 weeks (mean, 32.7 weeks; median, 20 weeks). Radiography revealed complete remission in 2 dogs and partial remission in 1 dog, for an overall response rate of 27%. Clinical problems such as nasal discharge (n = 11), sneezing (n = 6), and epistaxis (n = 4) resolved in 1 to 2 weeks in all dogs after beginning chemotherapy.

Nasal adenocarcinoma metastatic to bone in two dogs.

Diagnosis of nasal adenocarcinoma was made in a 6-year-old 35-kg neutered Golden Retriever and a 6-year-old 8-kg spayed mixed-breed dog with chronic bilateral nasal discharge unresponsive to antibiotics. Treatment for the Golden Retriever consisted of bilateral rhinotomy, curettage, and postoperative fractionated 48-Gy orthovoltage irradiation. The mixed-breed dog was treated with cisplatin. After complete remission of the primary neoplasm, the dogs were reevaluated because of acute lameness. Radiography of the right stifle of the Golden Retriever revealed soft tissue swelling, extensive bony destruction of the distal femoral metaphysis and epiphysis, and pathologic fracture involving the medial condyle. Radiography of the left scapula of the mixed-breed dog revealed lysis of the glenoid cavity and subchondral scapular bone. Diagnosis of metastatic carcinoma was made in both dogs. With treatment improvements and longer survival time of affected dogs, sinonasal neoplasia may be observed to develop in similar life-threatening metastatic sites.

Serum disposition of exogenous progesterone after intramuscular administration in bitches.

Progesterone was administered IM to 6 adult anestrous bitches at a dosage of 2 mg/kg of body weight. Serum progesterone concentrations were measured prior to progesterone administration and for 72 hours thereafter. The serum progesterone concentration time data were analyzed by use of a pharmacokinetics modeling computer program. The mean (+/- SD) peak serum progesterone concentration (34.3 +/- 7.8 ng/ml) was reached at 1.8 +/- 0.2 hours after progesterone administration. The mean serum progesterone concentration was 6.9 +/- 1.4 ng/ml at 24 hours and 2.0 +/- 0.4 ng/ml at 48 hours after progesterone administration. By 72 hours after administration, mean serum progesterone concentration was 0.9 +/- 0.2 ng/ml, which was comparable to serum progesterone concentrations prior to injection. The mean half-life of the absorption phase was 0.5 hours (range, 0.3 to 0.7 hours). The mean half-life of elimination was 12.1 hours (range, 9.5 to 13.8 hours). By analysis of the data, it was established that a dosage of 3 mg/kg, when the hormone was given IM to dogs once a day, would maintain serum progesterone concentration greater than 10 ng/ml.

Bone morphometrics and tetracycline marking patterns in young growing American alligators (Alligator mississippiensis).

Nine young American alligators (Alligator mississippiensis) were injected at monthly intervals with tetracycline to determine the bone apposition rate and the resorption patterns over a 3-mo period. The periosteal apposition rate increased progressively over the 3-mo period from 2.99 microns/day to 5.94 microns/day. Endosteal apposition rate was much slower with incomplete tetracycline lines being observed on the endosteum. This suggests that most modeling-resorptive activities occur on the endosteal envelope.