Outcome after surgical and conservative treatments of canine peritoneopericardial diaphragmatic hernia: A multi-institutional study of 128 dogs.

OBJECTIVE: To compare demographics and disease characteristics in dogs in which peritoneopericardial diaphragmatic hernia (PPDH) had been diagnosed and report outcomes after surgical treatment (ST) or conservative treatment (CT). STUDY DESIGN: Retrospective study. SAMPLE POPULATION: One hundred twenty-eight dogs (91 ST, 37 CT) in which PPDH had been diagnosed. METHODS: Medical records were reviewed for demographics, perioperative findings, and outcomes. Follow-up was obtained via telephone interview and email correspondence with owners and referring veterinarians. Baseline variables were compared between treatment groups. RESULTS: Dogs treated surgically were younger (P < .001), more likely to be sexually intact (P = .002), more likely to have clinical signs from PPDH vs an incidental diagnosis (P < .001), and more likely to have other congenital abnormalities (P = .003) compared with dogs treated conservatively. Ninety-seven percent of ST dogs were discharged from hospitals. Intraoperative and postoperative complications were reported in 22% and 41% of dogs, respectively, although most complications were classified as low grade (75% and 83%, respectively). Follow-up was available in 87 dogs, at a median of 1062 days. Hernia recurrence was not reported in any surgically treated dog. The deaths of nine dogs (five ST, four CT) could be attributed to PPDH, and long median survival times were observed in both the ST and CT groups (8.2 and 5 years, respectively). CONCLUSION: Preoperative characteristics differed between dogs treated conservatively vs surgically. Surgical treatment was associated with low operative mortality, and both ST and CT dogs had good long-term survival. CLINICAL SIGNIFICANCE: A diagnosis of PPDH can confer a good long-term prognosis for both ST and CT dogs.

Effect of perioperative desmopressin in cats with mammary carcinoma treated with bilateral mastectomy.

Perioperative administration of desmopressin has shown to significantly decrease rates of local recurrence and metastasis, and increase survival times in dogs with grade II and III mammary carcinomas. The objective of this study was to compare the oncologic outcome of cats with mammary carcinoma treated with bilateral mastectomy with or without perioperative administration of desmopressin. Medical records from nine veterinary institutions were searched to identify cats diagnosed with mammary carcinoma treated with bilateral mastectomy. Sixty cats treated with single-session or staged bilateral mastectomy were included. There were no significant differences in oncologic outcomes found between cats treated and not treated with desmopressin. No adverse effects were seen in any of the cats treated with perioperative desmopressin. Postoperative complications occurred in 18 cats (38.3%) treated with single-session bilateral mastectomy and in three cats (23.1%) treated with staged bilateral mastectomy (P = .48). Histologic grade and a modification of a proposed five-stage histologic staging system were both prognostic for disease-free interval. Incomplete histologic excision was associated with significantly increased rates of metastasis and tumour progression, and a shorter median survival time (MST). Cats that developed local recurrence also had a significantly shorter MST. The results of this study do not support the use of perioperative desmopressin to improve outcome when performing bilateral mastectomy for the treatment of mammary carcinoma in cats.

Comparison of lateral surgical margins of up to two centimeters with margins of three centimeters for achieving tumor-free histologic margins following excision of grade I or II cutaneous mast cell tumors in dogs.

OBJECTIVE: To determine whether conservative lateral surgical margins (equal to tumor diameter for tumors < 2 cm in diameter or 2 cm for larger tumors) were noninferior to wide (3-cm) lateral surgical margins for achieving tumor-free histologic margins following excision of grade I and II cutaneous mast cell tumors (MCTs) in dogs. ANIMALS: 83 grade I and II MCTs excised with a deep surgical fascial margin and requisite lateral surgical margins from 68 dogs from 2007 to 2017. Tumors representing scar revision or local recurrence were excluded. PROCEDURES: A pathology department database was searched to identify qualifying MCTs, and medical records were cross-referenced to obtain data regarding patients and tumors. Outcome (complete vs incomplete excision as histologically determined) was compared between conservative- and wide-margin groups. A noninferiority margin of ≥ 0.9 was used for the risk ratio (probability of complete excision for the conservative- vs wide-margin group), implying that noninferiority would be established if the data indicated that the true risk of complete excision with the conservative-margin approach was at worst 90% of that for the wide-margin approach. RESULTS: The proportion of excised MCTs with tumor-free histologic margins was similar between the conservative- (43/46 [93%]) and wide- (34/37 [92%]) margin groups. There were no differences in tumor diameter or location between treatment groups. The risk ratio (1.02; 95% confidence interval, 0.89 to 1.19) met the criterion for noninferiority. CONCLUSIONS AND CLINICAL RELEVANCE: The conservative-margin approach appeared to be noninferior to the wide-margin approach for achieving tumor-free histologic margins in the dogs of this study, and its use could potentially reduce the risk of postoperative complications. (J Am Vet Med Assoc 2020;256:567-572.