Chronic kidney disease in a giant panda (Ailuropoda melanoleuca): a case report.

BACKGROUND: Chronic kidney disease (CKD) is a common cause of morbidity and mortality in captive wildlife species. However, CKD has been rarely documented in giant pandas. CASE PRESENTATION: The following report describes a case of an eight-year-old female giant panda showing clinical signs of epistaxis, bloody diarrhea, polyuria, azotemia and anemia. The animal died despite of supportive treatments. Necropsy was performed. Grossly, both kidneys were shrunken and scarred with pallor. Subcutis edema and petechia on the epicardium of the heart were observed. The tissue samples were made into paraffin sections and stained by H.E and special staining including Periodic Acid-Schiff (PAS), von Kossa, Masson's trichrome, Phosphotungstic acid-hematoxylin (PTAH), and Congo red. Histopathology examination revealed severe chronic tubulointerstitial nephritis with marked interstitial fibrosis, glomerulosclerosis, tubular atrophy and calcification in kidneys, and acute necrotizing hemorrhagic myocarditis with calcification in heart. Other lesions included intestinal hemorrhage, hepatic fatty degeneration and necrosis with hemosiderin, and splenic hemosiderin. CONCLUSIONS: In summary, chronic kidney disease was finally diagnosed based on the association of clinical, gross, and histopathological findings. Heart failure secondary to CKD is the leading cause of death in this giant panda. The potential cause of CKD in this animal is possibly due to long term and uncontrolled hypertension. Blood pressure monitoring is essential in establishing the diagnosis and management of hypertension in giant panda.

Outcomes in Dogs with Multiple Sites of Cervical Intervertebral Disc Disease Treated with Single Ventral Slot Decompression.

In dogs with acute myelopathy but showing multiple sites of spinal compression from intervertebral disc disease (IVDD) on imaging, one approach is surgical decompression of the single acute disc extrusion while ignoring other previously extruded or protruded discs. However, little is known regarding the outcomes of this approach. This study described the outcomes and investigated prognostic factors in 40 dogs with multiple sites of cervical disc extrusion or protrusion on MRI who underwent ventral slot decompression for the single acute disc. The overall recovery rate was 97.5%. The median recovery time was seven days. The number of affected discs (including disc extrusion and protrusion) and the presence and number of the affected discs causing severe spinal compression did not influence the 30-day outcome. Compared with 23 dogs with single disc extrusion treated surgically, the recovery time and outcomes were similar between the two groups. The total number of affected discs was not associated with recovery time or outcomes. In conclusion, if an acute disc could be identified, ventral slot decompression targeting the single acute disc is a viable management approach for dogs with an acute presentation but diagnosed with multiple sites of spinal cord compression from IVDD.

Systemic mucormycosis caused by Rhizopus microsporus in a captive bottlenose dolphin.

A 6-year-old female bottlenose dolphin (Tursiops truncatus) kept in dolphinarium died after a 3.5-month period of lethargy and inappetence despite antibiotics and supportive care. At necropsy, gross findings included diffuse varying-sized nodules in the lungs and scattered nodules throughout the heart, spleen, mesenteric and hilar lymph node and kidney. Microscopically, the lesions were characterised by disseminated fungal pyogranulomas with numerous intralesional Mucor-like fungi. The fungi structures were demonstrated by Periodic acid-Schiff and Gomori methenamine silver stain. Molecular analyses of the fungi were Rhizopus microsporus by PCR sequencing 18S ribosomal RNA gene. Ziehl-Neelsen stain failed to show acid-fast bacterial infection. Based on pathological and molecular examination, systemic granulomatous mucormycosis was diagnosed. To our knowledge, this is the first reported case of systemic mucormycosis caused by Rhizopus microsporus in bottlenose dolphin.

Histopathology, Molecular Identification and Antifungal Susceptibility Testing of Nannizziopsis arthrosporioides from a Captive Cuban Rock Iguana (Cyclura nubila).

Chrysosporium-related fungi, the cause of superficial and deep mycoses, are an emerging infectious disease affecting not only reptiles but also immunocompromized humans. However, the information on Nannizziopsis arthrosporioides is extremely scarce. We herein characterized N. arthrosporioides isolated from a Cuban rock iguana (Cyclura nubila). Three skin ulcers were found in a Cuban rock iguana after captivity for 8 years. Microscopic examination revealed hyperplastic, hyperkeratotic, and ulcerative dermatitis coupled with numerous branched, septate fungal hyphae. The fungal culture yielded growth of zonate, felted cottony-powdery colonies with lobate margins on medium. Maximum-likelihood phylogeny tree based on the combined partial actin and partial ß-tubulin genes demonstrated that current isolates were mostly close to N. arthrosporioides. Furthermore, antifungal susceptibility test demonstrated that N. arthrosporioides had lowest minimal inhibitory concentration (MIC) values to isavuconazole, efinaconazole, and luliconazole, which may be the potential treatment of choice for N. arthrosporioides infection. The current study describes the first confirmed case of dermatomycosis caused by N. arthrosporioides of a captive reptile in Asia with detailed descriptions of the clinical, histopathological, and mycological features. The current findings provide new information on global distribution and host range of N. arthrosporioides and can raise the concern on the transboundary or emerging disease of N. arthrosporioides in Asian region.

Retroperitoneal extraosseous peripheral primitive neuroectodermal tumor in a Formosan serow: case report and literature review.

A 10-y-old female captive Formosan serow (Capricornis swinhoei) was inactive and was azotemic. An autopsy was performed following her death, and multiple irregularly shaped, white-to-gray masses of 0.5-2 cm diameter were noted on both ureters, the left adrenal gland, urinary bladder, and uterus. Microscopically, organs were effaced by a poorly demarcated, highly infiltrative neoplasm, composed of neoplastic round cells arranged in islands, sheets, or nests with occasional rosette formation. The neoplastic cells were small: ≤2 red blood cell (≤ 15 µm) diameter. The neoplastic cells were positive for CD56, CK, FLI-1, and NSE, but negative for desmin, GFAP, melan A, NF, PAX-8, S100, synaptophysin, and vimentin. Therefore, the diagnosis of retroperitoneal extraosseous peripheral primitive neuroectodermal tumor (pPNET) was made. pPNET with FLI-1 expression has not been reported previously in animals, to our knowledge.

Concurrent leukoencephalomyelitis and polyneuritis in a Maltese terrier: resembling combined central and peripheral demyelination in humans.

A one-year-old male Maltese terrier presented with mild ataxia and disorientation for 4 months. Over time, clinical signs progressed from paraparesis to non-ambulatory tetraparesis, voice change and dysphagia. Histological examination revealed concurrent leukoencephalomyelitis and polyneuritis. Infectious etiologies, including dengue, Japanese encephalitis, Zika, canine distemper, pseudorabies, rabies, toxoplasmosis, neosporosis, leishmaniasis, and encephalitozoonosis, were ruled out by PCR and/or immunohistochemical (IHC) staining. IHC tested on neurological tissues highlighted a heterogeneous population of infiltrating T and B lymphocytes admixed macrophages. Therefore, this case was diagnosed with current leukoencephalomyelitis and polyneuritis, resembling combined central and peripheral demyelination (CCPD), an autoimmune inflammatory demyelinating disease affecting both the CNS and PNS in humans.

Urothelial Carcinomas of the Urinary Bladder With Plasmacytoid or Rhabdoid Features and Tendency of Epithelial-Mesenchymal Transition in 3 Dogs.

Plasmacytoid and rhabdoid variants of urothelial carcinomas (UCs) of the urinary bladder have been described in humans with plasma cell-like or rhabdoid cellular appearance and aggressive clinical outcome. Canine UC of the bladder is generally classified as papillary/nonpapillary and infiltrating/noninfiltrating with limited information regarding other histological patterns. We report 3 cases of UC of the urinary bladder showing a unique discohesive cellular morphology with malignant behavior resembling the human plasmacytoid and rhabdoid variants of UC, which may raise some difficulties in diagnosis. Epithelial-mesenchymal transition and reduced E-cadherin expression were revealed by immunohistochemistry in 2 cases, possibly explaining the discohesive and invasive behavior of the tumor cells. The findings broaden the morphological spectrum as well as the distinct clinical features of canine UC of the urinary bladder.

A 3-year surveillance on causes of death or reasons for euthanasia of domesticated dogs in Taiwan.

Over the last 2 decades, there has been growing interest in research on the mortality of domesticated pets. These studies relied on an effective data-collecting system. During 2012-2014, a real-time reporting system was designed for mortality data in owned dogs and cats. The present retrospective study aimed to report on the causes of death (CODs) or reasons for euthanasia (RFEs) in domesticated dogs in Taiwan, and to investigate CODs/RFEs segregated by demographic variables. Data from 2306 domesticated dogs were acquired during the 3-year period in the present study. The median age at death of the study population was 10.2 years (median interquartile range 7.0-14.0; range 0.0-25.0). Crossbred, female, and neutered dogs showed greater ages at death than other groups. The most common COD/RFE was neoplasia, followed by multiple organ involvement (MOI) and cardiovascular diseases. Segregated by cut-off ages, the most common COD/RFE was infection among dogs younger than 3 years or 1year, and neoplasia among dogs at or older than 3 years or 1year of age; the most common COD/RFE was neoplasia among dogs younger than median age, and MOI among dogs at or older than median age. Segregated by geographic variables, the ranking and frequency of CODs/RFEs displayed different patterns between the capital city/non-capital areas, and among areas stratified by human population densities. The study provides various insights into age at death and CODs/RFEs in owned-dog population in Taiwan, and provides new directions for future research.

Mycolactone-producing Mycobacterium marinum infection in captive Hong Kong warty newts and pathological evidence of impaired host immune function.

A mass mortality event of captive Hong Kong warty newts Paramesotriton hongkongensis with non-granulomatous necrotic lesions occurred in Taipei Zoo, Taiwan, in 2014. Clinically, the sick newts were lethargic and often covered with water mold Saprolegnia sp. on the skin of the body trunk or extremities. Predominant pathological findings were multifocal non-granulomatous necrotic lesions in the liver, spleen, and kidneys and severe skin infection with Saprolegnia sp., with deep invasion and involvement of underlying muscles. The possibility of ranavirus infection was ruled out by negative PCR results. Unexpectedly, abundant intralesional acid-fast positive bacilli were found in the necrotic lesions of the liver, spleen, and kidney in all 14 sick newts. PCR targeting the hsp65, ITS region, and partial 16S rRNA genes was performed, and the sequence identity from amplified amplicons of hsp65 and partial 16S rRNA genes was 100% identical to that of the corresponding gene fragment of Mycobacterium marinum. Further molecular investigations demonstrated that the current M. marinum was a mycolactone-producing mycobacterium with the presence of esxA/esxB genes. Mycolactone is a plasmid-encoded, immunosuppressive, and cytotoxic toxin. The possible immunosuppression phenomenon characterized by systemic non-granulomatous necrotic lesions caused by M. marinum and the unusual deep invasive infection caused by water mold might be associated with the immunosuppressive effect of mycolactone. Therefore, it should be noted that non-granulomatous necrotic lesions in amphibians can be caused not only by ranavirus infection but also by mycobacteriosis.

A real-time reporting system of causes of death or reasons for euthanasia: A model for monitoring mortality in domesticated cats in Taiwan.

A novel, real-time mortality recording system was designed to collect mortality data in companion animals from veterinary hospitals in Taiwan. This retrospective study aims to introduce the system, and to utilize the data collected for further investigation of the lifespan and mortality of the domesticated cat population stratified by demographic variables. Our data revealed that 1325 domesticated cats were acquired between 2012 and 2014. The median age of the study population was 8.0 years (IQR 3.0-13.0; range 0.0-22.7). Neutered and purebred cats lived longer. The most common causes of death were renal and urologic disorders, followed by neoplasia, infection, cardiovascular disorders, and trauma. Independent factors for common causes were surveyed. Advanced age and neutering was found to be associated with death due to renal and urologic disorders as well as with neoplasia. In contrast, younger age was found to be associated with death due to trauma and infection; being unneutered and living in the capital city were found to be associated with death due to trauma. Being male or purebred was found to be associated with death due to cardiovascular disorders.

Outbreak of thiamine deficiency in cats associated with the feeding of defective dry food.

Objectives The objective of this study was to determine disease progression, association between neurological signs and magnetic resonance imaging (MRI) findings, and long-term outcome in feline thiamine deficiency associated with defective dry food. Methods The clinical records of 17 cats diagnosed with thiamine deficiency related to a defective dry food were examined and data collected. The thiamine level in the food was analysed by liquid chromatography-tandem mass spectrometry. Results The thiamine level in the food was below the recommendation of the National Research Council. Fifteen cats were fed the food exclusively. Prior to the acute development of neurological signs, most cats displayed non-specific signs such as anorexia, lethargy or vomiting. Vestibular signs of varying severity were observed in 94% of the cats, and all but one of these presented with bilateral dysfunction. Other main neurological signs included altered mentation (76%), blindness (59%) and seizures (59%). Moreover, 80% of the cats with seizures presented with cluster seizures or status epilepticus. MRI abnormalities consistent with findings reported in the previous literature were detected in five cases. MRI was unremarkable in one cat with ongoing severe neurological signs even though thiamine had been administered. Most surviving cats recovered rapidly within 2 weeks of treatment and had either returned to normal or had minimal neurological signs at the 2 month follow-up. One cat recovered slowly over 6 months. Most cats with seizures in the initial stage of the disease remained seizure free at the 24 month follow-up. Conclusions and relevance This study documented the association between feline thiamine deficiency and defective dry food. MRI examination provided valuable information in the diagnosis. However, normal MRI findings do not exclude the diagnosis of feline thiamine deficiency, especially once thiamine has been supplemented. MRI findings also may not always reflect the neurological status or severity. If treated promptly, most cats will recover rapidly with a good outcome. Occasionally, recovery may be slow and take several months.

Concurrent spindle-cell thymoma and thymic cysts in a Barbary sheep (Ammotragus lervia): case report and review of the literature.

An ~21-year-old female Barbary sheep (Ammotragus lervia) died spontaneously following a lengthy episode of difficulty in walking. An ~6 × 3 × 3 cm, unilocular cystic growth was found in the cranioventral thorax. The fibrotic cystic wall, lined by a single layer of flattened to cuboidal epithelial cells, was invaginated and partially encircled solid masses of fusiform neoplastic cells with multiple intratumoral cystic structures. The fusiform neoplastic cells were intensely positive for cytokeratin (CK) and partially positive for α-smooth muscle actin and vimentin, but negative for thyroid transcription factor-1 (TTF-1) and neuron-specific enolase (NSE). The intratumoral cysts were lined by CK-positive but TTF-1- negative, NSE-negative, flattened, cuboidal to columnar epithelial cells, suggestive of cystically dilated medullary duct epithelium-derived structures. Based on the location and histopathologic findings of the growth, concurrent spindle-cell thymoma and thymic cysts was diagnosed. We also discuss the correlation between thymic cysts and thymoma and review the literature of thymomas in ovine and wildlife species.

A renal adenocarcinoma in a corn snake (Pantherophis guttatus) resembling human collecting duct carcinoma.

A 5-year-old male captive corn snake (Pantherophis guttatus) with caudal coelomic swelling was admitted for surgical treatment. Laparotomy revealed a 5 × 4 × 2.5 cm, firm, expansile, irregularly shaped mass arising from the middle portion of the right kidney with a mild lobulated pattern and mottled white-to-tan. Microscopically, the mass was composed of numerous bizarre angulated tubules of polygonal neoplastic cells separated by a scirrhous stroma with remarkable heterophilic infiltrates. The neoplastic cells were nonciliated and mucin secreting, with abundant brightly eosinophilic cytoplasm. There were marked cellular and nuclear atypia, frequent cell individualization, and stromal invasion, indicative of malignant behavior, which was confirmed by metastasis to the left kidney 1.5 months postoperatively. Both neoplastic epithelial cells and mesenchymal cells contributing to the scirrhous stroma had variable immunopositivity for pan-cytokeratin. The neoplasm was considered a renal adenocarcinoma resembling human collecting duct carcinoma.

Simultaneous visual inspection for barometric whole-body plethysmography waveforms during pulmonary function testing in client-owned cats.

OBJECTIVES: For the purpose of applying a barometric whole-body plethysmography (BWBP) device as a routine clinical tool in client-owned cats, the objective of this study was to evaluate the methodological importance of simultaneous visual inspection (SVI) of graphic tracing. METHODS: To investigate the effect of SVI on the results obtained, 50 client-owned cats were included. Breath-by-breath analysis was conducted with BWBP software, and a commonly used rejection setting was chosen for automatic elimination (AE) of non-breath artefactual waveforms, according to tidal volume (TV), inspiratory and expiratory time, and the difference between inspiratory and expiratory volumes. During 10 mins of data recording, SVI for BWBP waveforms was performed to record manually time periods that were free of any artefacts. The two datasets derived from AE alone (AEA method) and AE plus SVI (SVI-AE method) were compared. The inter-observer effect on the process of SVI was evaluated on six cats. RESULTS: There were statistically significant differences (P <0.001) between the AEA and SVI-AE datasets for most BWBP parameters. Bland-Altman analysis of the parameter-enhanced pause (Penh) showed heterogeneous variances, indicating less agreement when the Penh values were large. Intra-individual coefficients of variation of Penh were significantly higher with the AEA method than with the SVI-AE method (61.1% vs 34.7%, respectively; P <0.001). Inter-observer agreement on the SVI process was excellent, and no statistically significant differences between the two observers were found for any BWBP parameters obtained by the SVI-AE method (P >0.05). CONCLUSIONS AND RELEVANCE: Visual inspection for BWBP waveforms in real time can reliably identify stable breathing signals in client-owned cats. The obtained results were significantly different when the SVI method was used in addition to AE. In the interpretation of BWBP parameters or comparison of measurements among studies, whether an SVI methodology was applied should be considered.

Downregulation of the KLF4 transcription factor inhibits the proliferation and migration of canine mammary tumor cells.

Canine mammary tumor (CMT) is the most common neoplasm in female dogs, and over 50% of CMTs are diagnosed as malignant. Krüppel-like factor 4 (KLF4) is a member of the KLF family of transcription factors and is associated with cell proliferation, differentiation, migration, and apoptosis. Although the role of KLF4 is still controversial in various human cancers, KLF4 has been identified as an oncogene in human breast cancer. Moreover, high KLF4 expression is correlated with an aggressive phenotype in CMT. Therefore, investigating the function of KLF4 may help better understand the pathogenesis of CMT. In this study, partial sequences of canine KLF4 and KLF4 expression were identified in various normal canine tissues, as well as CMT cells and Madin-Darby canine kidney (MDCK) cells. Kenpaullone, a small molecule inhibitor of KLF4, downregulated KLF4 expression in CMT cells and reduced CMT cell proliferation, migration, and colony formation in soft agar. Kenpaullone treatment induced S and G2/M phase arrest in CMT and MDCK cells, and induced death in CMT cells, but not in MDCK cells. It was concluded that KLF4 is expressed in various normal canine tissues, and downregulation of KLF4 inhibited CMT cell proliferation and migration, and induced cell death. The results of this study suggest that KLF4 may represent a suitable therapeutic target for CMT therapy.

Functional assessment of expiratory flow pattern in feline lower airway disease.

Feline lower airway disease (FLAD) is a chronic respiratory disease of which there is a lack of information on functional assessment in current veterinary medicine. The purposes of this study were to investigate expiratory pattern and evaluate the diagnostic utility of functional parameters in cats with FLAD. Thirty-three client-owned cats (23 FLAD cats and 10 control cats) were studied. Under quiet tidal breathing, pseudo-tidal breathing flow-volume loop (pTBFVL) was obtained from a barometric whole body plethysmography (BWBP) device. There were significant differences in the shapes of expiratory, but not inspiratory, curves between FLAD and control cats. The incidence of the presence of concave expiratory curve indicating lower airway obstruction was 74% in FLAD cats. To assess the diagnostic utility of pTBFVL indices in cats with FLAD, area under the receiver-operator curve was 0.86 for PEF/EF50 (peak expiratory flow divided by expiratory flow at end expiratory volume plus 50% tidal volume); a cuff-off value of PEF/EF50 >1.51 distinguished normal from FLAD (73.9% sensitivity, 100% specificity). There were no significant differences in traditionally measured BWBP parameters (ie, enhanced pause) between cats with and without FLAD in the present study. In conclusion, underlying change on expiratory flow pattern during natural tidal breathing existed in FLAD cats, and selected pTBFVL indices were useful in discriminating FLAD from normal cats. Tidal breathing pattern depicted by pseudoflow-pseudovolume loops from a BWBP system could be a non-invasive tool for functional assessment in client-owned cats.

Meningothelial meningioma in a Malayan sun bear (Helarctos malayanus).

A 24-year-old, spayed female Malayan sun bear (Helarctos malayanus) in the Taipei Zoo (Taipei, Taiwan) showed clinical signs of slowly progressive anorexia, dullness, compulsive pacing, and circling. The animal subsequently developed acute severe stupor and persistent recumbency. Postcontrast study of computed tomography revealed a spheroid, extra-axial mass with strong but heterogeneous hyperattenuation in the left temporal lobe of the cerebrum. At necropsy, a solitary, well-circumscribed intracranial mass measuring 3 cm × 2.5 cm × 2 cm was attached to the left pyriform lobe with compression of the adjacent neuroparenchyma. Cytological examination obtained from the mass revealed large clumps and sheets of cohesive polyhedral cells with round nuclei, wispy cytoplasm, and indistinct cell borders. Microscopically, the mass was composed of densely packed round to polygonal cells arranged in lobules and small nests. Psammoma bodies, xanthomatous change, and cholesterol deposition were also noted. Immunohistochemical staining of the tumor was positive for vimentin, pancytokeratin, cytokeratin (CK)34BE12, neuron-specific enolase, and epithelial membrane antigen, but negative for glial fibrillary acidic protein and S100 protein. The cytological, histological, and immunohistochemical features were compatible with a meningothelial meningioma.

Expression of autophagy-related protein Beclin-1 in malignant canine mammary tumors.

BACKGROUND: Autophagy is a self-catabolic mechanism that degrades unnecessary cellular components through lysosomal enzymes. Beclin-1, an autophagy-related protein, establishes the first connection between autophagy and tumorigenesis. The purpose of this study is to assess the Beclin-1 expression pattern and to determine its prognostic significance in patients with malignant canine mammary tumor (CMT). RESULTS: We examined Beclin-1 expression in 70 cases of malignant CMTs by immunohistochemistry. Cytoplasmic Beclin-1 expression was significantly weaker in cancer cells than in nearby normal mammary glands (p < 0.001). Low cytoplasmic expression (57.14%) was associated with older age, lower degree of tubular formation, increased mitotic activity, higher histologic grade, and extensive necrosis. Low nuclear expression (40%) was connected with older age, lower degree of tubular formation, extensive necrosis, and negative for Her2/neu overexpression. Univariate survival analysis showed that Beclin-1 cytoplasmic expression was a poor prognostic factor for overall survival rate (p < 0.001). Multivariate survival analysis demonstrated that Beclin-1 cytoplasmic expression is an independent prognostic factor (p = 0.016). CONCLUSIONS: Loss of Beclin-1 is associated with aggressive clinicopathologic features and poor overall survival. The results suggest that Beclin-1 plays an important role in tumor progression of malignant CMTs.

KIT gene exon 11 mutations in canine malignant melanoma.

The proto-oncogene KIT encodes a receptor tyrosine kinase which has been shown to be upregulated in canine melanomas. KIT mutations lead to constitutive phosphorylation and activation of KIT in the absence of ligand binding. The presence of KIT mutations and KIT protein expression was examined in a cohort of 49 dogs with canine malignant melanoma. An exon 11 synonymous nucleotide 1743C→T mutation was identified in five cases in which one also harbored a L579P mutation. Tumors that harbored the KIT exon 11 mutation(s) correlated significantly with disease recurrence (P = 0.05). All 36 melanomas available for immunohistochemical analysis showed either weak (16 cases, 44.4%) or strong (20 cases, 55.6%) expression of the KIT protein. The five KIT mutation carriers were all strongly positive for KIT by immunohistochemical staining. These findings suggest that a subset of canine malignant melanomas harbors a KIT exon 11 mutation.