Retroperitoneal pyogranulomatous and fibrosing inflammation secondary to fungal infections in two dogs.

CASE DESCRIPTIONS: A 4-year-old spayed female Golden Retriever (dog 1) was examined because of acute edema and erythema in the left hind limb and an inguinal mass, and a 5-year-old female Jack Russell Terrier (dog 2) was examined because of a recurring retro-peritoneal mass. CLINICAL FINDINGS: Dog 1 had an edematous, hyperemic left hind limb with a fixed inguinal mass. Monocytic neutrophilic leukocytosis and hypoalbuminemia were detected. Diagnostic imaging revealed abnormal tissue surrounding the larger vessels and ureters and complete occlusion of the left limb veins. Surgery resulted in incomplete removal of the mass. Histologic examination revealed fibrosing pyogranulomatous inflammation. Results of a Histoplasma antigen test were positive, and reanalysis of the tissues revealed yeast cells indicative of Histoplasma capsulatum. Dog 2 had incomplete removal of a retroperitoneal mass. Histologic examination revealed fibrosing pyogranulomatous inflammation. The mass recurred 8 months later in dog 2; exploratory abdominal surgery at that time resulted in substantial hemorrhage from the adhered caudal aorta. Histologic examination of tissue sections from the second surgery revealed yeast cells consistent with Blastomyces dermatitidis. TREATMENT AND OUTCOME: Both dogs had temporary improvement after surgery. Full clinical resolution required treatment for fungal disease. Dog 1 was treated with itraconazole, then fluconazole (total treatment time, 23 weeks). Dog 2 was treated with fluconazole for 36 weeks. CLINICAL RELEVANCE: Retroperitoneal pyogranulomatous fibrosis caused by fungal infections has not been reported in veterinary medicine. There was substantial morbidity, but the prognosis can be good when this abnormality is recognized and antifungal medications are administered.

Injection timing determines whether intragastric ethanol produces conditioned place preference or aversion in mice.

Previous studies have shown that mice develop conditioned place preference (CPP) when ethanol is administered by intraperitoneal (ip) or intravenous (iv) injection. The present studies examined CPP in mice using the intragastric (ig) route of administration. Inbred mice were surgically implanted with chronic intragastric cannulae and exposed to an unbiased place conditioning procedure in which infusion of ethanol (2 or 4 g/kg) was paired with a conditioned stimulus (CS+). A different CS was paired with water. In Experiments 1-2, ethanol was infused just before exposure to CS+. Contrary to previous studies involving intraperitoneal injection, infusion of 4 g/kg ig ethanol produced a significant conditioned place aversion (CPA). However, when a 5-min delay was inserted between infusion and CS exposure (Experiments 3-4), the same dose produced CPP. These outcomes are not consistent with expectations derived from a recent study in selectively bred rats, suggesting that sensitivity to ethanol reward is enhanced by intragastric administration. However, the finding that intragastric ethanol can produce either CPP or CPA depending on dose and injection timing is consistent with previous intraperitoneal ethanol studies in mice. Although the parameters differ for each route of administration, it appears that the same underlying processes can be invoked to explain how manipulation of injection timing affects the direction of ethanol-induced place conditioning. More specifically, in both cases, CPA can be attributed to an initial, short-lived aversive effect, whereas CPP can be attributed to a delayed rewarding effect of ethanol.