Incomplete ovariosalpingectomy and subsequent malignant granulosa cell tumor in a female green iguana (Iguana iguana)

Case Description-A 9-year-old spayed female green iguana (Iguana iguana) was evaluated because of a distended coelom and weight loss. History included a single episode of egg binding and subsequent bilateral ovariosalpingectomy.;Clinical Findings-Physical examination revealed a mass within the coelomic cavity. Ultrasonography revealed a large, irregular mass with hypoechoic regions and coelomic effusion. Clinicopathologic derangements included heterophilia, monocytosis, lymphopenia, basophilia, hypocholesterolemia, hypoproteinemia, and hypercalcemia. Results of cytologic evaluation of the mass were suggestive of malignant epithelial neoplasia, but neoplastic cells were not found in the effusion. An ovarian tumor was suspected on the basis of clinical signs, clinicopathologic findings, and results of cytologic evaluation of the mass.;Treatment and Outcome-Surgical exploration revealed a large left ovary, a normal-appearing contralateral ovary, and a mass in the fat body, all of which were removed and submitted for histologic examination. The histologic diagnosis was granulosa cell tumor with metastasis to the fat body. The patient died 11 months after evaluation, and disseminated granulosa cell tumor was confirmed at necropsy; histologic examination at that time also identified systemic mastocytosis.;Clinical Relevance-Granulosa cell tumors are uncommon in reptiles, and this was the first granulosa cell tumor described antemortem cytologically, histologically, and ultrastructurally in an iguana. Findings in this iguana underscored concerns associated with incomplete oophorectomy of iguanas; cytologic and histopathologic findings were similar to those observed in other domestic animals. Oophorectomy should be considered as an alternative to standard ovariosalpingectomy to avoid potential complications in pet reptiles, and use of microsurgical instruments and vascular clips is advised. (J Am Vet Med Assoc 2011239:237-242)

Variation in stress reactivity affects cage-induced stereotypies in female CD-1 (ICR) mice

Stereotypies in captive animals typically occur under conditions that are stressful for the animals, and there is some anecdotal evidence that stress levels during early stereotypy development predict later stereotypy levels. Based on this and on the involvement of stress in the behavioural sensitization to psychostimulant drugs, it has been hypothesized that stereotypy development might be causally related to stress. To address this question further, we used mice of the commercial outbred stock CD-1 (ICR) and mice of two lines derived from the outbred CD-1 (ICR) strain by selective breeding for high (HR) and low (LR) stress reactivity, respectively, and examined whether genetically driven variation in stress reactivity is associated with variation in the expression of cage-induced stereotypies. From 21 days of age, 10 females of each line were housed in pairs under standard laboratory conditions until they were video recorded for stereotypic behaviour and tested for corticosterone responses in a stress reactivity test (SRT) at 12 weeks of age. As expected, HR females showed a significantly stronger corticosterone response in the SRT than LR females, while ICR females were intermediate. Unexpectedly, however, both HR and LR females showed very low levels of stereotypic behaviour, while ICR females developed the high levels of stereotypies typical for this strain of mouse. Consequently, there was no significant relationship between measures of acute corticosterone reactivity and stereotypy performance, but a trend for reduced recovery of the corticosterone response in the ICR line suggests that variation in recovery rather than the acute response might predict stereotypy levels in these mice. (C) 2011 Elsevier B.V. All rights reserved.

Cage-induced stereotypies in female ICR CD-1 mice do not correlate with recurrent perseveration

Stereotypies are repetitive, unvarying, apparently purposeless behavioural patterns. They develop in animals kept in barren environments and are highly prevalent in laboratory mice (Mus musculus), yet their underlying mechanisms have remained elusive. In humans, stereotypies are associated with several psychiatric disorders and are thought to reflect dysfunction of inhibition of motor programs mediated by the corticostriatal circuitry, resulting in recurrent perseveration (=inappropriate repetition of behavioural responses). Several studies in captive animals of different species have reported a correlation between stereotypy performance and perseverative behaviour, indicating a similar dysfunction. To examine whether stereotypies in mice correlate with recurrent perseveration and whether they are causally related, we raised 40 female ICR CD-1 mice in either barren or enriched cages from three to either six or 16 weeks of age (2 x 2 factorial design) and assessed stereotypic behaviour in the home cage and recurrent perseveration on a two-choice guessing task. Enrichment significantly reduced stereotypic behaviour both at six and 16 weeks of age and recurrent perseveration increased with age. Although enriched housing reduced the number of repetitions in the guessing task significantly, there was no clear evidence for an effect on recurrent perseveration, and recurrent perseveration did not correlate positively with stereotypy level. These findings indicate either that this test did not measure recurrent perseveration or that cage stereotypies in these mice do not reflect behavioural disinhibition as measured by recurrent perseveration.