Congenital glaucoma in a tiger (Panthera tigris)

Objective

To describe a case of congenital glaucoma in atiger (Panthera tigris).

Animal Studied

An 8-month-old intact female tiger wasreferred for suspected glaucoma of the right eye. The right eye was buphthalmicwith moderate episcleral injection, circumferential superficial cornealneovascularization, moderate corneal edema, and a fixed dilated pupil. Tapetalreflection was absent due to a mature cataract. Rebound tonometry under generalanesthesia revealed 70 mmHg and 21 mmHg in the right and left eye, respectively.

Procedure

A trans-conjunctival enucleation was performedand the globe was submitted for histopathology.

Results

Histopathology revealed a thin sclera, amorphousmaterial contouring an imperforate and hypoplastic iridocorneal angle, ahypoplastic lens with severe anterior-posterior compression, subcapsularepithelial hyperplasia, and Morganian globules, and segmental moderate retinalatrophy. Periodic acid-Schiff stain highlighted segmental dilations of theDescemet's membrane. Masson trichrome stain highlighted a pre-irido collagenmembrane.

Conclusion

The tiger's age and histopathologic findingsare consistent with congenital goniodysgenesis. This is the first known reportof congenital glaucoma in a tiger.     

Disseminated histoplasmosis in a Bengal tiger (Panthera tigris)

Disseminated infection with Histoplasma capsulatum was diagnosed in a 7-yr-old female Bengal tiger (Panthera tigris). Clinical signs were nonspecific with the exception of brief periods of tachypnea for 5 days prior to death. H. capsulatum organisms were found in the lungs, tracheobronchial lymph nodes, and liver. Diagnosis was confirmed by tracheal wash, urine H. capsulatum enzyme immunoassay, and necropsy results. This report represents the first published account of disseminated histoplasmosis in a tiger.     

Abdominal pythiosis in a Bengal tiger (Panthera tigris tigris).

An adult Bengal tiger (Panthera tigris tigris) housed in an outdoor sanctuary in Florida exhibited vomiting, diarrhea, and weight loss. A clinical workup did not reveal the source of the clinical signs and antibiotic therapy was unrewarding. Radiographs revealed the presence of an abdominal mass. The tiger died during an immobilization for a follow-up clinical examination. A necropsy was performed and tissue samples of intestine and mesenteric lymph nodes were submitted for histopathologic diagnosis. A pyogranulomatous panenteritis and lymphadenitis with intralesional hyphae led to a presumptive etiologic diagnosis of intestinal/abdominal pythiosis. The diagnosis of pythiosis was confirmed by serology and immunoblotting.     

Endoparasites of the Siberian tiger (Panthera tigris altaica)

There have been few reports on the diversity and prevalence of parasitic fauna of the endangered Siberian tiger, which inhabits the territory of the Russian Far East. The present review attempts to summarize the information about the parasitic fauna of wild Siberian tigers, which includes 15 helminths and 3 protozoan species. The most prevalent parasitic species was found to be Toxocara cati, followed by Toxascaris leonina. Another commonly recorded Platyhelminth species is Paragonimus westermani, which causes a lethal infection of the lung parenchyma in Siberian tigers. However, the information about infections by this fluke in the Siberian tigers is scarce, although P. westermani infections pose a serious health hazard to tiger populations. The nematodes Aelurostrongylus abstrusus and Thominx aerophilus are found in Siberian tigers with an occurrence rate of 2.3% and 19%, respectively. The information on the parasitic infestations of captive populations of Siberian tigers is also presented along with the sources of infection and hazards for the wild tiger populations in their natural environment.     

Pyelonephritis associated with Staphylococcus intermedius in a Siberian tiger (Panthera tigris altaica)

Pyelonephritis, in which Staphylococcus intermedius was isolated, was diagnosed in a 4-year-old female Siberian tiger (Panthera tigris altaica). At necropsy, the renal pelvis was dilated with a large amount of purulent exudates. Microscopically, the lesions of renal pelvis and medulla consisted of necrotic foci intermingled primarily with numerous degenerative neutrophils and a few lymphocytes, plasma cells and macrophages. Bacteriology showed the presence of S. intermedius. This is the first report on pyelonephritis associated with S. intermedius in wild felidae.     

Pericardial mesothelioma in a Bengal tiger (Panthera tigris).

A 17-year-old Bengal tiger (Panthera tigris) presented with dyspnea and tachypnea. Radiographs revealed severe pleural and pericardial effusion, but no obvious mass. During attempts to remove the fluid under anesthesia, the cat developed cardiac tamponade and died. At necropsy, a nodular mass was found at the heart base and was identified as a pericardial mesothelioma. This is the first report of this tumor in any large cat.     

Caudal cervical disc protrusion in a Bengal tiger (Panthera tigris tigris).

A young adult male white Bengal tiger (Panthera tigris tigris) presented with hindlimb ataxia. Cervical and lumbar myelography revealed a compressive lesion of the cord at C(6-7). Corticosteroid therapy and confinement failed to provide lasting remission of signs. A modified, inverted cone ventral slot decompression was used to remove the fibrous material causing cord compression at C(6-7). Temporary Horner's syndrome and laryngeal paresis developed postsurgically because of excessive tissue retraction. The animal recovered normal ambulatory function 6 wk after surgery.     

Nasopharyngeal myxosarcoma in a Bengal tiger (Panthera tigris).

An 18- to 25-yr-old intact female Bengal tiger (Panthera tigris) was diagnosed antemortem and postmortem with nasopharyngeal myxosarcoma metastatic to the lung, chronic lymphoplasmacytic otitis media, and lymphoplasmacytic and eosinophilic stomatitis. Myxosarcomas are rare in domestic animals and seldom metastasize; this tumor has not been previously reported in an exotic felid. Computed tomography of the skull was used during the diagnoses.     

A thymic carcinoid in a Bengal tiger (Panthera tigris).

An 18-yr-old Bengal tiger (Panthera tigris) presented with acute onset hind limb paresis. Radiographic and ultrasonographic imaging revealed a caudal abdominal aortic thrombus and a cranial mediastinal mass. Necropsy confirmed aortic thrombosis. Necrotizing enteritis and multifocal renal thrombosis were also noted. The cranial mediastinum contained a bilobed mass that histologically and ultrastructurally was consistent with a carcinoid.     

Mammary carcinoma in a tiger (Panthera tigris): morphological and immunohistochemical study

The histologic and immunohistochemical features of a case of mammary gland carcinoma are described in a 14-yr-old female tiger (Panthera tigris). Immunoreactivity to estrogen receptor (ER), progesterone receptor (PR), tumoral protein 53 (p53), vascular endothelial growth factor (VEGF), human epidermal growth factor receptor 2 (HER-2), and cyclooxigenase-2 (COX-2) was investigated. Neoplastic cells were negative for ER, PR, and p53 but showed positivity for VEGF, HER-2, and COX-2, both in the primary and the metastatic lesions. Histopathologic findings and immunohistochemistry results suggested that the malignant behavior of the reported case could be comparable with some aggressive cat mammary carcinomas.     

Combination therapy for footpad lesions in a captive Bengal tiger (Panthera tigris tigris).

A captive adult male Bengal tiger (Panthera tigris tigris) was treated for chronic footpad ulcers associated with pacing on concrete cage surfaces. Combination therapy of oral fluoxetine and acepromazine administration to diminate pacing behavior, daily application of moisturizing ointment, and oral vitamin E supplementation resulted in complete resolution of all footpad lesions. Subsequent clinical episodes completely resolved with similar treatments.     

Fibrocartilaginous embolic myelopathy in a Sumatran tiger (Panthera tigris sumatrae).

An adult, captive-born Sumatran tiger (Panthera tigris sumatrae) had been ataxic for approximately 3 mo and had been self-mutilating after an acute onset of unilateral paresis and Homer's syndrome. Histologic lesions in the cervical spinal cord were consistent with fibrocartilaginous embolic myelopathy (FCEM), and they included the presence of cartilaginous occlusion of spinal blood vessels. This is the first reported case of FCEM in a large felid and specifically a Sumatran tiger.     

Conservative management of pyothorax in an Amur tiger (Panthera tigris altaica)

Therapy for pyothorax, or pleural empyema, has not been described for large felids. This case describes the successful treatment of pyothorax in a captive, large felid. A 15-yr-old multiparous, female Amur tiger (Panthera tigris altaica) presented with nonspecific clinical signs caused by an insidious onset of pyothorax. Management of pyothorax cases in companion animals often involves thoracostomy tube placement with recurrent drainage of the pleural cavity, intensive supportive care, and monitoring. In this case, conservative management was elected because hospitalization was not a viable option. Thoracocentesis was performed to drain as much fluid from the chest cavity as possible, yielding more than 1.3 L. Corynebacterium sp. and unidentified anaerobic gram-positive cocci were cultured. Treatment included cefovecin subcutaneously, oral antibiotic therapy with clindamycin and marbofloxacin, meloxicam, and restricted exercise by minimizing access to the main exhibit. Significant improvement was noted clinically and radiographically 6 wk later, and no relapses were noted in the following weeks. An examination 11.5 mo later confirmed resolution.     

Chordoma of the thoracic vertebrae in a Bengal tiger (Panthera tigris tigris)

A 19-year-old female Bengal tiger (Panthera tigris tigris) was presented with hind limb weakness, ataxia and respiratory distress. Computed tomography revealed a mass between the left side of the T7 vertebra and the base of the left 7th rib. The tiger then died, and necropsy was performed. Grossly, the vertebral mass was 6 × 5.7 × 3 cm, and invaded the adjacent vertebral bone and compressed the T7 spinal cord. Histologically, the mass was composed of large, clear, vacuolated and polygonal cells with osteochondral matrix. Cellular and nuclear atypia were moderate. The vacuolated cells stained positively for cytokeratin and vimentin and negatively for S-100. Based on these findings, the present case was diagnosed as a vertebral chordoma; the first report in a tiger.     

Disseminated coccidioidomycosis in a captive Indochinese tiger (Panthera tigris corbetti) with chronic renal disease.

A 19-yr-old, 78.2-kg captive female Indochinese tiger (Panthera tigris corbetti) from the El Paso Zoo (El Paso, Texas, USA) with chronic renal disease was euthanized after a 10-day course of anorexia, depression, progressive rear limb weakness, muscle fasciculations, and head tremors. Postmortem findings included pericardial effusion, generalized lymphadenopathy, glomerulosclerosis, glomerular atrophy with membranous glomerulonephropathy, and pancreatic adenocarcinoma. Pyogranulomatous pneumonia, pericarditis, and lymphadenitis were associated with fungal spherules histomorphologically consistent with Coccidioides immitis. Rising antibodies to C. immitis were detected on samples obtained perimortem and 2 mo before euthanasia. Retrospective serology was negative for two additional Indochinese tigers, two Iranian leopards (Panthera pardus saxicolor), two jaguars (Panthera onca), two bobcats (Lynx rufus texensis), two ocelots (Leopardus pardalis), and three Amur leopards (Panthera pardus orientalis) housed at the zoo over an 8-yr period. Despite being located within the endemic region for C. immitis, this is only the second case of coccidioidomycosis reported from this institution.     

Sumatran tiger (Panthera tigris sumatrae): A review of conservation status

The majority of wild Sumatran tigers are believed to live in 12 Tiger Conservation Landscapes covering approximately 88 000 km². However, the actual distribution of tigers across Sumatra has never been accurately mapped. Over the past 20 years, conservation efforts focused on the Sumatran tigers have increased, but the population continues to decline as a result of several key threats. To identify the status of the Sumatran tiger distribution across the island, an island-wide questionnaire survey comprised of 35 respondents from various backgrounds was conducted between May and June 2010. The survey found that Sumatran tigers are positively present in 27 habitat patches larger than 250 km² and possibly present in another 2. In addition, a review on major published studies on the Sumatran tiger was conducted to identify the current conservation status of the Sumatran tiger. Collectively, these studies have identified several key factors that have contributed to the decline of Sumatran tiger populations, including: forest habitat fragmentation and loss, direct killing of tigers and their prey, and the retaliatory killing of tigers due to conflict with villagers. The present paper provides management authorities and the international community with a recent assessment and a base map of the actual distribution of Sumatran tigers as well as a general overview on the current status and possible future conservation challenges of Sumatran tiger management.     

Klinefelter syndrome (39 XXY) in an adult Siberian tiger (Panthera tigris altaica).

Fibroblast cultures of a skin biopsy from an adult intact male Siberian tiger (Panthera tigris altaica) revealed an abnormal standard and G-banded karyotype diploid chromosome number of 2n = 39 XXY due to an extra sex chromosome as opposed to the expected 2n = 38 XY. The tiger was euthanatized 1 yr later due to acute multifocal intervertebral disc disease. Histopathology of the reproductive tract demonstrated a paucity of seminiferous tubules and these were devoid of spermatagonia. An increase in fibrous connective tissue was noted in sections of the prostate and epididymis, and expansion of the fibrous interstitium was observed in the testes.