Factors associated with dehiscence and mortality rates following gastrointestinal surgery in dogs.

OBJECTIVE: To identify factors associated with dehiscence and mortality rates following gastrointestinal surgery in dogs. ANIMALS: 170 client-owned dogs that underwent gastrointestinal surgery from 2010 to 2016. PROCEDURES: Medical records of all included dogs were reviewed to collect information on preoperative (breed, sex, age, body weight, American Society of Anesthesiologists [ASA] physical status classification, emergency status, and plasma lactate concentration), intraoperative (indication for surgery, type of surgery, and whether bacterial peritonitis was identified), and postoperative (development of dehiscence and survival status at 2 weeks after surgery) factors. Preoperative and intraoperative factors were evaluated for associations among each other and with postoperative factors. RESULTS: Univariate analyses revealed that preoperative plasma lactate concentration increased with increasing ASA status, and lactate concentrations were significantly higher for nonsurvivors (mean ± SD, 4.6 ± 3.7 mmol/L) than for survivors (2.4 ± 1.7 mmol/L). Multivariate analysis controlling for age, body weight, and plasma lactate concentration revealed that dogs with an ASA status ≥ 3 were more likely to develop dehiscence after gastrointestinal surgery than were dogs with a lower ASA status (OR, 17.77; 95% confidence interval, 2.17 to 144.06). Multivariate analysis also revealed that dogs with an ASA status ≥ 3 or high lactate concentration were less likely to survive than were other dogs. CONCLUSIONS AND CLINICAL RELEVANCE: These findings regarding ASA status and preoperative plasma lactate concentration and their associations with outcome may help clinicians to determine and provide optimal perioperative care to dogs requiring gastrointestinal surgery as well as to inform owners about prognosis.

Role of pulmonary intravascular macrophages in endotoxin-induced lung inflammation and mortality in a rat model.

BACKGROUND: Bile-duct ligated (BDL) rats recruit pulmonary intravascular macrophages (PIMs) and are highly susceptible to endotoxin-induced mortality. The mechanisms of this enhanced susceptibility and mortality in BDL rats, which are used as a model of hepato-pulmonary syndrome, remain unknown. We tested a hypothesis that recruited PIMs promote endotoxin-induced mortality in a rat model. METHODS: Rats were subjected to BDL to induce PIM recruitment followed by treatment with gadolinium chloride (GC) to deplete PIMs. Normal and BDL rats were treated intravenously with E. coli lipopolysaccharide (LPS) with or without GC pre-treatment followed by collection and analyses of lungs for histopathology, electron microscopy and cytokine quantification. RESULTS: BDL rats recruited PIMs without any change in the expression of IL-1beta, TNF-alpha and IL-10. GC caused reduction in PIMs at 48 hours post-treatment (P < 0.05). BDL rats treated intravenously with E. coli LPS died within 3 hours of the challenge while the normal LPS-treated rats were euthanized at 6 hours after the LPS treatment. GC treatment of rats 6 hours or 48 hours before LPS challenge resulted in 80% (1/5) and 100% (0/5) survival, respectively, at 6 hours post-LPS treatment. Lungs from BDL+LPS rats showed large areas of perivascular hemorrhages compared to those pre-treated with GC. Concentrations of IL-1beta, TNF-alpha and IL-10 were increased in lungs of BDL+LPS rats compared to BDL rats treated with GC 48 hours but not 6 hours before LPS (P < 0.05). CONCLUSION: We conclude that PIMs increase susceptibility for LPS-induced lung injury and mortality in this model, which is blocked by a reduction in their numbers or their inactivation.

A Review of the Surgical Management of Perineal Hernias in Dogs.

Perineal hernia refers to the failure of the muscular pelvic diaphragm to support the rectal wall, resulting in herniation of pelvic and, occasionally, abdominal viscera into the subcutaneous perineal region. The proposed causes of pelvic diaphragm weakness include tenesmus associated with chronic prostatic disease or constipation, myopathy, rectal abnormalities, and gonadal hormonal imbalances. The most common presentation of perineal hernia in dogs is a unilateral or bilateral nonpainful swelling of the perineum. Clinical signs do occur, but not always. Clinical signs may include constipation, obstipation, dyschezia, tenesmus, rectal prolapse, stranguria, or anuria. The definitive diagnosis of perineal hernia is based on clinical signs and findings of weak pelvic diaphragm musculature during a digital rectal examination. In dogs, perineal hernias are mostly treated by surgical intervention. Appositional herniorrhaphy is sometimes difficult to perform as the levator ani and coccygeus muscles are atrophied and unsuitable for use. Internal obturator muscle transposition is the most commonly used technique. Additional techniques include superficial gluteal and semitendinosus muscle transposition, in addition to the use of synthetic implants and biomaterials. Pexy techniques may be used to prevent rectal prolapse and bladder and prostate gland displacement. Postoperative care involves analgesics, antibiotics, a low-residue diet, and stool softeners.