Hyperglycemic hyperosmolar state in a chimpanzee (Pan troglodytes).

A 19-year-old female chimpanzee (Pan troglodytes) presented for cachexia, acute weakness, hyporexia, icterus, and polyuria. The animal was diagnosed with a hyperglycemic hyperosmolar state, which is a well-recognized syndrome in diabetic humans that is rarely diagnosed in animals. This case documents an important and likely under-reported syndrome in non-human primates.

Perineal repair of a full-thickness rectal prolapse in a wild Sumatran orangutan (Pongo abelii).

A Delorme's procedure perineal surgical repair was performed in a wild adult male Sumatran orangutan (Pongo abelii) with a chronic persistent rectal prolapse that had been unsuccessfully treated by 6 previous surgeries. The rectal prolapse did not recur, and the orangutan was successfully released to the wild, 6 weeks later.

ANTEMORTEM DIAGNOSIS AND SUCCESSFUL TREATMENT OF A COMPLETE MOLAR PREGNANCY IN A GERIATRIC BONOBO ( PAN PANISCUS).

A 47-yr-old multiparous female bonobo ( Pan paniscus) tested positive for pregnancy on a routine urine test. Because this geriatric animal was considered postreproductive, oral contraception had been discontinued. Sequential transabdominal ultrasound evaluations were performed under voluntary behavior and revealed that the uterus contained a mass of heterogenous tissue which was rapidly increasing in size. Due to a lack of normal fetal development and the ultrasonographic appearance of the uterine tissue, a molar pregnancy was suspected. Ovariohysterectomy was performed, and a complete hydatidiform mole was confirmed through human chorionic gonadotropin levels as well as gross and histological examination of the uterus. To the authors' knowledge, this is the first time a complete molar pregnancy has been reported antemortem in a nonhuman great ape, although a single case of partial hydatidiform mole was previously documented in a chimpanzee on postmortem examination. This case describes the successful medical and surgical management of complete molar pregnancy in a bonobo and provides support for extending the age range of birth control recommendations in geriatric captive great apes that exhibit active breeding behavior.

MAMMARY GLAND ADENOCARCINOMA IN A MALE BORNEAN ORANGUTAN (PONGO PYGMAEUS).

An adult male Bornean orangutan ( Pongo pygmaeus ) was diagnosed with invasive, poorly differentiated grade 9/9 mammary gland adenocarcinoma from a subcutaneous mass that was surgically removed during a routine preventative health examination. The tumor was tested for estrogen and progesterone receptors, human epidermal growth factor receptor 2 (HER2), and HER2 fluorescence in situ hybridization (HER2 FISH). Whole blood was tested for breast cancer 1 (BRCA1) and breast cancer 2 (BRCA2) genes. The orangutan was treated orally with two common human breast cancer drugs; tamoxifen and anastrozole. The orangutan lived for 4.5 yr postdetection, dying from an unrelated cause. This is the first reported case of mammary gland adenocarcinoma in a male great ape.

Ovariectomy due to a dermoid cyst in an orangutan (Pongo pygmaeus).

A large abdominal mass was identified during an elective preventative health examination in a 25-yr-old female hybrid orangutan (Pongo pygmaeus). Sonographically, the mass was fluid-filled and a presumptive diagnosis of a dermoid cyst or cystic teratoma of an ovary was made. Exploratory laparotomy, after assembly of a surgical team, confirmed that the 2.5-kg cystic mass was associated with the left ovary. Following ovariectomy, perioperative dissection of the mass revealed hair components, confirming the working diagnosis. Because the right ovary was slightly nodular and firmer than expected, and these germ cell tumors sometimes occur bilaterally, excision of the contralateral ovary was elected. Histopathology confirmed the left ovarian mass was a dermoid cyst; the right ovary contained a corpus hemorrhagicum but no evidence of neoplasia. Recovery was uneventful and the orangutan was prescribed hormone replacement therapy to mitigate potential problems associated with a chronic lack of estrogen and progesterone. This case report demonstrates the importance of elective examinations under anesthesia, even in well-trained great apes.

Diagnosis and treatment of diffuse large B-cell lymphoma in an orangutan (Pongo pygmaeus).

Lymphoma is a common malignancy observed in companion animals. This type of naturally occurring neoplasia has been uncommonly reported in great apes. Diffuse large B-cell lymphoma was diagnosed in an 8-yr-old captive orangutan (Pongo pygmaeus) with gastrointestinal disease by histologic and immunohistochemical methodologies. The orangutan was treated with three cycles of combination chemotherapy (intravenous Rituxan, cyclophosphamide, doxorubicin, and vincristine). The primate has been in good health and exhibiting normal behaviors for more than 15 mo following treatment.

Obstructive uropathy secondary to uterine leiomyoma in a chimpanzee (Pan troglodytes).

Complications due to uterine leiomyomata in chimpanzees have rarely been documented. Here we describe a female chimpanzee that developed severe hydronephrosis in the right kidney due to leiomyoma. Because hysterectomy did not alleviate the hydronephrosis, nephrectomy was elected. After these procedures, the chimpanzee is doing well. Leiomyomata screening programs with treatment algorithms are a useful component of a comprehensive chimpanzee program.

Bilateral phacoemulsification in an orangutan (Pongo pygmaeus).

A 14-year-old, female, captive-born orangutan (Pongo pygmaeus) developed bilateral cataracts. Ultrasonography, electroretinography and cataract correction using phacoemulsification were performed bilaterally. This case report aims to describe the ophthalmic procedures performed in this animal critically endangered of extinction. The surgery successfully restored vision and normal activity to the patient.

Treatment of a retroperitoneal abscess by omentalization in an orangutan (Pongo pygmaeus pygmaeus).

A 38-yr-old orangutan (Pongo pygmaeus pygmaeus) presented with chronic lethargy and difficulty in locomotion that progressed to weakness, anorexia, and permanent dorsal and/or lateral recumbency. The orangutan was immobilized with ketamine. Abdominal ultrasonography revealed a mass in the caudal portion of the abdomen. Exploratory surgery was performed, but the mass could not be resected. Instead, the mass was drained and omentalized in an attempt to establish continuous drainage after surgery. The only complication was a wound infection that was treated locally with a disinfectant and installation of a drain that was changed every 2 days under anesthesia. Omentalization was successful in providing continuous fluid drainage for this retroperitoneal abscess and required minimal postoperative handling of the animal.

Uterine adenomyosis in an orang-utan (Pongo abelii/pygmaeus).

A 48-year-old, multiparous, female hybrid orang-utan (Pongo abelii/pygmaeus) was investigated after a 3-year history of irregular and excessively heavy menstrual bleeding. Opportunistic pelvic examinations over a 2.5-year period were non-diagnostic. Medical therapy was not effective. A subtotal hysterectomy with bilateral salpingo-ovariectomy was performed. A pedunculated mass spanning 90% of the uterine lumen was seen grossly, and histopathology confirmed uterine adenomyosis. Adenomyosis is defined as the ectopic occurrence or diffuse implantation of endometrial tissue, including glands and stroma, into the myometrium. It is common in older, usually premenopausal, multiparous women and is frequently associated with other uterine pathology, including endometrial hyperplasia and leiomyomas. The most common clinical signs are dysmenorrhoea and heavy menstrual bleeding; however, up to 35% of women are asymptomatic. Diagnosis is difficult and requires myometrial sampling and an experienced pathologist. A hysterectomy in this case was diagnostic and curative. There have been few reports of uterine adenomyosis in non-human primates and none reported in an orang-utan. Uterine adenomyosis should be considered in the differential diagnosis in any multiparous, aged, non-human female primate with irregular and excessively heavy menstrual bleeding, and hysterectomy with bilateral salpingo-ovariectomy is recommended as a diagnostic and therapeutic solution.

Repeat laparotomy for the treatment of septic peritonitis in a Bornean orangutan (Pongo pygmaeus pygmaeus).

A 9-yr-old female Bornean orangutan (Pongo pygmaeus pygmaeus) presented with a 48-hr history of depression, lethargy, anorexia, and mucoid discharge from the rectum. Clinical, radiographic, and ultrasonographic examination demonstrated the presence of multiple distended loops of intestine, intestinal adhesions, and free gas within the abdomen. During exploratory laparotomy, fibrinopurulent diffuse peritonitis as a result of a ruptured intrapelvic abscess with associated large bowel adhesions was evident. The abdomen was thoroughly lavaged, necrotic debris and abscess wall removed, and fibrinous adhesions disrupted. The orangutan was kept sedated for 48 hr to allow for intensive care. Six months later, when the orangutan presented with similar clinical signs, ultrasonographic examination demonstrated the presence of a pelvic abscess. The previous procedure was repeated with the addition of a hysterectomy. This report is the first documentation of long-term management following surgical intervention for internal abdominal abscessation and septic peritonitis in a great ape.

Nevus lipomatosus cutaneus superficialis (Hoffmann-Zurhelle) in a chimpanzee (Pan troglodytes).

BACKGROUND: A 32-year-old, male chimpanzee (Pan troglodytes) kept in a zoo developed a focally extensive, proliferative, cerebriform, dermal mass at the left inner thigh extending to the inguinal region. After surgical removal, the mass recurred and extended progressively over a period of 5 years. METHODS AND RESULTS: At necropsy, a 20 x 20 cm large, well defined, papular and partly verrucous, rubbery mass composed of multiple large, soft nodules measuring up to 4 cm in diameter was observed in the left thigh and inguinal region. Histological examination revealed a multifocal expansion of the dermis by mature adipocytes that were arranged in small islands to large lobular aggregates. Dermal proliferations of adipocytes were almost completely separated from the subcutaneous adipose tissue. CONCLUSIONS: This is the first report of a unique lesion that resembles human Nevus lipomatosus cutaneus superficialis in a chimpanzee and is different from lipoma or liposarcoma.

Acute appendicitis in a chimpanzee (Pan troglodytes).

BACKGROUND: A 7-year old, female chimpanzee (Pan troglodytes) developed acute abdominal pain and anorexia. An irregular, mineral opacity was identified in the caudal right quadrant of the abdomen on radiographs and computed tomography scan, which appeared to be in the region of the cecal appendage. RESULTS AND CONCLUSIONS: A diagnosis of acute appendicitis was made based on clinical signs, abnormal haematology findings, and consultation with a human radiologist. Exploratory laparotomy was performed and the cecal appendage was removed. On histologic examination, the mucosal epithelium contained eosinophilic and neutrophilic inflammation. The inflammation extended through the tunica muscularis to the serosal surface and adjacent mesentery. The histologic findings were consistent with acute appendicitis in humans. The chimpanzee recovered well from surgery with immediate improvement in clinical signs and no post-operative complications.

Lumbar diskectomy in a human-habituated mountain gorilla (Gorilla beringei beringei).

The authors report a case of a human-habituated mountain gorilla, Alvila, resident at the San Diego Zoo, who was found to have a herniated intervertebral lumbar disc after being attacked by the gorilla troop's silverback male gorilla. Ultimately, the gorilla required surgical intervention for her disease and made a full recovery. To our knowledge, this is the only known case of spine surgery. A 36-year-old female human-habituated mountain gorilla (Gorilla beringei beringei), resident at the San Diego Zoo, was noticed by caregivers to walk with a substantial limp after being attacked by the gorilla troop's silverback male gorilla. Magnetic resonance (MR) imaging of her lumbar spine revealed a large herniated disk at the L1-2 level on the right. This finding appeared to correlate well with the gorilla's symptoms. The gorilla underwent a lumbar diskectomy under loupe. Post-operatively the gorilla did very well. The right leg weakness was immediately improved post-operatively. The gorilla continued to "crutch walk" initially, swinging on the upper extremities and not bearing weight on the lowers. However, by 2 weeks the limp was no longer noticeable to the zoo caregivers. The wound healed well and there was no evidence of wound infection or CSF leak. The gorilla was reunited with her troop and has reintegrated well socially. With 10 months of follow-up, the gorilla continues to do well. This is the only known case of spine surgery in a gorilla. For best surgical results, one needs to consider the similarities and differences between the gorilla and human vertebral anatomy. We believe that careful pre-operative planning contributed to the good early post-operative result. Ultimate assessment of the long-term outcome will require additional follow-up.

Surgical procedure and postoperative management of a perineal urethrostomy in a chimpanzee (Pan troglodytes).

A chimpanzee (Pan troglodytes) with traumatic loss of the distal penis developed a gradually enlarging ventral urethral swelling and progressive dysuria. Endoscopy identified a urethral diverticulum, and endoscopic resection of the diverticulum wall was performed. Postoperative infection caused extensive necrosis of the penis, which necessitated a perineal urethrostomy. Complications of the urethrostomy included urethral obstruction from recurrent urethral stricture. The stricture was managed by regular dilatation using urethral bougies. Because of considerable postoperative swelling, catheterization was required to allow micturition following both the diverticular resection and polyp debulking. A shortened catheter sutured to the skin was tolerated for up to 10 days. Four yr after the urethrostomy, the animal is healthy and asymptomatic with endoscopic examinations performed at 12 mo intervals. This case demonstrates that with appropriate aftercare, perineal urethrostomy is an effective technique in the treatment of chronic distal urethral obstruction in the chimpanzee and probably other primate species.

Reversal of neurologic deficit in an adult gorilla with severe symptomatic lumbar stenosis.

STUDY DESIGN: A case report is presented. OBJECTIVE: To describe a case of severe symptomatic lumbar stenosis in an adult gorilla successfully treated with decompressive surgery. SUMMARY OF BACKGROUND DATA: Although spinal degenerative disease is thought to be less common in apes than in humans, gorillas and bonobos are known to have higher rates of disease than other African apes. METHODS: A 42-year-old female gorilla presented with a history of progressive lower extremity weakness. She was unable to ambulate normally or climb, pulling herself around with her arms. Her keeper did not believe she was incontinent. Physical examination revealed that ankle plantarflexion and dorsiflexion were absent on the right and weak on the left. Radiographs revealed disc space narrowing with osteophytes at the last mobile segment. Myelogram and computed tomography revealed severe spinal stenosis at the last two mobile segments. Under general anesthesia, a standard laminectomy and bilateral lateral recess decompression were performed. RESULTS: There were no anesthetic or wound complications. The gorilla was noted to have improved ankle strength bilaterally on postoperative day 1. On postoperative day 3, the animal began to walk and climb. At 20 months, the animal is back to her neurologic baseline. CONCLUSIONS: Symptomatic lumbar degenerative disease with neurologic compromise may be treated surgically, with excellent outcome, in the adult gorilla. Though this is an unusual situation, knowledge that this is a potentially reversible condition may benefit other gorillas in captivity.

Cataract surgery with foldable intraocular lens implants in captive lowland gorillas (Gorilla gorilla gorilla).

Two juvenile, male, captive-born lowland gorillas (Gorilla gorilla gorilla) with the same father but different mothers developed bilateral cataracts. The cataracts were surgically removed within 6 yr and 3 mo, respectively, of diagnosis, and foldable intraocular lenses were implanted. Although vision was not restored in one eye with a mature, 6-yr-old cataract in gorilla A, surgical intervention on the other eye was performed before a complete cataract developed, and vision was fully restored. Gorilla B was treated at the age of 17 mo, and normal visual development proceeded in both eyes. This animal developed bilateral after-cataract and therefore needed a second intervention in both eyes using Nd:YAG laser treatment. The genetic component of juvenile cataracts should be considered in breeding management programs.

Rectal prolapse in a free-ranging mountain gorilla (Gorilla beringei beringei): clinical presentation and surgical management.

A juvenile female mountain gorilla (Gorilla beringei beringei) of the Mubare tourist group in Bwindi Impenetrable National Park, Uganda, developed a severe, complete rectal prolapse that did not spontaneously resolve. Eight months prior, a juvenile female mountain gorilla of the Mubare group developed a mild, complete rectal prolapse that resolved spontaneously within 24 hr. Field guides reported that spontaneously resolving prolapses had been seen previously in two other juveniles, one of which was from the Mubare group. The tissue became increasingly necrotic and maggot infested over the course of 1 wk. Surgical intervention involved amputation of the affected rectal tissues and suturing the viable portion to the anal sphincter muscle with simple interrupted absorbable sutures. The surgery was performed in the field in accordance with Uganda Wildlife Authority policies. Antibiotics and anthelmintics were administered systemically, and the gorilla returned to the group. The gorilla appeared to recover fully after 3 wk. Histology of the resected rectal tissue confirmed intense inflammation and necrosis with myiasis but did not reveal an underlying etiology.