OBJECTIVES:To describe the prevalence, clinical presentation, and histopathological features of primary glaucoma (PG) in a French population of domestic rabbits. ANIMALS STUDIED:Client-owned rabbits, presented to the Ophthalmology Unit of Alfort from January 2017 to December 2024, were diagnosed with glaucoma. PROCEDURES:A retrospective review of medical records was performed. Rabbits were included if they presented signs of ocular hypertension associated with an IOP exceeding 20 mmHg. Cases with signs of secondary glaucoma were excluded. Ophthalmic examination findings, gonioscopy (when available), treatment, outcomes, and histopathological results (of enucleated eyes) were analyzed. RESULTS:Out of 211 rabbits examined for ocular disease, 35 were diagnosed with glaucoma (16.6%). Primary glaucoma was suspected in 4 rabbits (8 eyes), representing 11.4% of glaucomatous rabbits and 19.5% of affected eyes. Affected rabbits had bilateral glaucoma and belonged to various breeds (giant, lop, and dwarf rabbits). Clinical signs included buphthalmos, corneal edema, and mydriasis; IOP ranged from 23 to 65 mmHg. Gonioscopy, performed in 3 eyes, revealed collapsed iridocorneal angles. Topical antiglaucoma treatment and diode laser cyclophotocoagulation were largely ineffective. Histopathological analysis of three eyes showed features consistent with anterior segment dysgenesis in one rabbit and inconclusive findings without secondary causes of glaucoma in the other. CONCLUSIONS:Primary glaucoma may be more prevalent in pet rabbits than previously recognized. Despite treatment, long-term control of IOP and preservation of vision remain challenging. Early detection is essential, and further prospective studies are warranted to better characterize the disease and optimize management.

An accessory tragus-a congenital malformation of part of the external ear-is an abnormal appendage developed from the first pharyngeal (or branchial) arch. In humans, an accessory tragus can be associated with other abnormalities as part of congenital malformative syndromes, most of which are transmitted in an autosomal dominant mode. Three cutaneous exophytic lesions were detected in the right preauricular region of a 2.5-y-old, castrated male European shorthair cat. Two of these lesions were submitted for histologic examination and were diagnosed as accessory tragi. They consisted of a vertical axis of loose collagenous tissue with hair follicles and sebaceous glands covered by a simple fold of epidermis. The epidermis was of normal thickness and slightly hyperpigmented. Only the pretragal lesion contained a central core of well-differentiated elastic cartilage. To our knowledge, accessory tragus has not been reported previously in cats and has been reported only once in veterinary medicine, in a dog with a solitary unilateral lesion. For pathologists, the diagnosis of this rare lesion may not be straightforward, especially if the cartilaginous core is absent or the location of the sample is unknown.

In humans and cats, pancreatic carcinoma (PC) arising from the exocrine pancreas is considered an aggressive cancer associated with a poor prognosis due to its high metastatic rate. The aim of this retrospective multi-institutional study was to investigate tissue expression of biomarkers of tumour invasiveness, metastasis and immune escape in cats with PC. A secondary aim was to correlate the overall immunohistochemical scores (OISs) with histological characteristics, presence of metastasis and survival. Immunohistochemistry for COX-2, E-cadherin, CD44, c-KIT and PD-L1 was performed on 40 PC tissue samples. CD44 was expressed in all PCs with 27 (67 %) having a moderate to high OIS. PD-L1, E-cadherin, COX-2 and c-KIT expression was seen in 20 (50 %), 21 (52 %), 18 (45 %) and 14 (35 %) cases, respectively, with predominantly low OISs. Metastasis was present in 43 % of cats with a median survival time (MST) of 7 days (95 % CI 0-20; range, 1-1,094) and a 1-year survival rate of 13.8 %. When excluding cats that died or were euthanized at diagnosis, the MST was 19 days (95 % CI 0-99; range, 2-1,094). No statistical associations were found between COX-2, E-cadherin, PD-L1, CD44 or c-KIT OIS and histological subtype, necrosis, vascular invasion, mitotic count, presence of metastasis or survival. Positive E-cadherin expression was significantly associated with the presence of perineural invasion (P = 0.009; OR 1.50 [95 % CI 1.11-2.03]).

Objectives Cyclooxygenase-2 (COX-2), a pivotal enzyme in the cyclooxygenase family, plays a critical role in carcinogenesis. While its expression is well documented in various neoplasms in humans and dogs, data on COX-2 expression in feline neoplasms, particularly nasal malignant epithelial tumours, is limited. This study aimed to evaluate COX-2 expression in feline nasal malignant epithelial tumours through immunohistochemistry. We hypothesised that these tumours would exhibit COX-2 expression, consistent with findings in humans and dogs. Methods Formalin-fixed, paraffin-embedded biopsy samples from feline nasal malignant epithelial tumours were retrospectively analysed for COX-2 expression by immunohistochemistry. Biopsies from cats previously treated with non-steroidal anti-inflammatory drugs were excluded. Immunohistochemistry was performed with a monoclonal rabbit antibody, with feline renal macula densa cells serving as the positive control. The immunoreactive score (IRS) combined a semiquantitative estimation of immunolabelled neoplastic cells with labelling intensity. Scores in the range of 0–1 were classified as negative, 2–3 as low, 4–8 as intermediate and greater than 8 as high COX-2 expression levels. Results A total of 18 feline nasal biopsies (nine adenocarcinomas, seven carcinomas, one squamous cell carcinoma and one mucinous carcinoma) were included. Clinical signs included nasal discharge, sneezing, epistaxis and inspiratory dyspnoea. COX-2 expression was not detected in any case (IRS = 0). Follow-up data were available for 7/18 cats. The overall median survival time after diagnosis in our cohort was 667 days (range 0–1642). Conclusions and relevance In contrast to canine nasal malignant epithelial tumours, COX-2 expression was not observed in feline nasal malignant epithelial tumours. These results suggest species-specific differences in COX-2 expression in nasal malignant epithelial tumours. Further studies evaluating other carcinogenesis pathways, such as vascular endothelial growth factor or platelet-derived growth factor, seem crucial to better understand feline nasal malignant epithelial tumours and to improve their therapeutic management.

A subcutaneous tumor was identified in the lateral neck of a wild adult serotine bat (Eptesicus serotinus). Histologic examination revealed a non-encapsulated, poorly demarcated, densely cellular and infiltrative round-cell neoplasm, with cytonuclear atypia and a high mitotic count. Neoplastic cells had numerous Giemsa-positive metachromatic intracytoplasmic granules leading to a diagnosis of subcutaneous mast cell tumor (MCT). Immunohistochemical analysis demonstrated positive staining for KIT with a diffuse cytoplasmic pattern, confirming the mastocytic origin. The tumor had histologic features suggestive of malignant behavior, which was confirmed by the metastatic mast cells in the regional lymph node adjacent to the tumor. MCT has not been reported previously in a chiropteran species, to our knowledge. Based on this case, MCTs in this species have malignant potential, and their diagnosis may require additional stains and immunohistochemistry (IHC). Our results support further investigation regarding the utility and prognostic value of KIT IHC in bats in this context.

Cutaneous mast cell tumors are rarely reported in cattle. Although mutations in the c-KIT gene have been shown to play a central role in the oncogenesis of canine mast cell tumors, few data are available in cattle. This report describes the clinical, histologic, immunohistochemical, and genetic features of a multicentric cutaneous mast cell tumor in an adult cow. An 11-year-old Prim'Holstein cow was presented for a 5-month history of multiple skin nodules. Cytologic and histologic analyses of the nodules led to a diagnosis of mast cell tumors. Immunohistochemical analysis for KIT expression showed a moderate to strong signal in neoplastic mast cells with a cytoplasmic and membranous pattern. Sequencing of the c-KIT gene coding sequence revealed no mutation. Despite partial response after corticosteroid treatment, euthanasia was elected. No metastases to the lymph nodes, spleen, and liver were identified at post-mortem and histologic examinations.

Dogs and cats may suffer from a variety of diseases, mainly immune mediated, that require the administration of immunosuppressive drugs. Such therapies can cause adverse effects either by the toxicity of the drugs or as a consequence of immune suppression and associated opportunistic infections. Here we present an, yet unknown, association of Toxoplasma gondii and Alternaria fungus, within cutaneous lesions in a dog under long-term immunosuppressive therapy. The diagnosis of such infections is laborious and not obvious at first glance, since the clinical signs of cutaneous toxoplasmosis, neosporosis or alternariosis are not specific. A further laboratory confirmation is needed. Therefore, we currently recommend that dogs and cats should undergo serologic testing for toxoplasmosis or neosporosis prior to immunosuppressive therapy and a regular dermatological evaluation during the immunosuppressive therapy.

OBJECTIVE To describe a case of lipogranulomatous conjunctivitis in a horse. ANIMAL STUDIED A client-owned 12-year-old Standardbred gelding presenting with chronic conjunctivitis and palpebral masses. METHODS Complete ophthalmic examination, surgical excision, histopathology, and bacterial culture of biopsy samples were performed. RESULTS Upper and lower eyelids of both eyes were affected, with multiple yellow-to-white nodules on the palpebral conjunctiva, adjacent to the eyelid margin. Nodule removal was achieved via partial tarsal plate excision. Histopathological examination revealed granulomatous inflammation and large droplets of presumed free lipid in the conjunctival lamina propria. The animal was diagnosed with lipogranulomatous conjunctivitis. No postoperative ocular discomfort was observed for months; however, 3 years later, new conjunctival nodules were noticed, requiring a second surgical procedure on three of the eyelids. Transient entropion in the left lower eyelid was observed 2 months after the second surgery, and no recurrence of conjunctival nodules was observed after 18 months of follow-up. CONCLUSION To our knowledge, this is the first report of lipogranulomatous conjunctivitis in horses.

This file contains supplementary figures showing prostate tumor kinetics (Fig S1) and histology (Fig S2) for the two mouse models, the validation of regimens (Fig S3 and S4), the effects of diets (Fig S5) and aging (Fig S6) on cancer hallmarks, and the results of cell studies complementary to main Figures 3 and 4.

This file contains the legends for the 7 supplementary figures

This file contains the list of antibodies (Table S1), and the sequences of primers (Table S2) and siRNAs (Table S3)

Case summaryA 5-year-old castrated male domestic shorthair cat presented with a 3-month history of weight loss, chronic diarrhoea and vomiting. Examination revealed a large proximal duodenal lesion eventually diagnosed as feline gastrointestinal eosinophilic sclerosing fibroplasia (FGESF) associated with fungal filaments. Histological examination was performed following endoscopic biopsy. Direct examination and mycological culture of the duodenal biopsies revealed the presence of a siphomycetous fungus, which was further identified as Rhizopus microsporus. Treatment with prednisolone and ciclosporin for 3 months led to complete resolution of the clinical signs and marked improvement of the endoscopic lesions. Specific fungal treatment with amphotericin B was poorly tolerated. Relevance and novel informationTo the best of our knowledge, this is the first report of the characterisation of a siphomycetous fungus associated with FGESF lesions, and the first endoscopic description and diagnosis of FGESF without surgical biopsies. We hypothesise that the presence of R microsporus occurred because of disrupted mucosal integrity.

A 3-month-old female French Bulldog presented with hematuria, severe pollakiuria, and urinary incontinence lasting for 1.5 months. Broad-spectrum empirical antibiotic therapy and nonsteroidal anti-inflammatory drugs were initiated by the referring veterinarian. Due to a lack of improvement, the dog was referred. At referral examination, urinary clinical signs persisted (hematuria, severe pollakiuria) and a firm bladder was noted. Abdominal ultrasonography revealed severe, diffuse bladder wall thickening with a significant reduction in the bladder lumen. Urinary tract endoscopy showed whitish exophytic proliferations throughout the entire bladder wall. Histological bladder wall analysis led to a diagnosis of bladder malakoplakia. Prolonged antibiotic therapy with fluoroquinolones was prescribed and resulted in clinical remission despite persistent bacteria in the bladder wall. This report describes a case of successfully medically managed bladder malakoplakia, a very rare condition in veterinary medicine, well documented in humans.

This prospective case series investigated potential uterine causes of infertility in queens. Purebred queens with infertility (failure to conceive, embryonic death, or failure to maintain pregnancy and produce viable kittens), but no other reproductive disorders were examined approximately 1-8 weeks before mating (Visit 1), 21 days after mating (Visit 2), and 45 days after mating (Visit 3) if pregnant at Visit 2. Investigations included vaginal cytology and bacteriology, urine bacteriology, and ultrasonography. At Visit 2 or 3, uterine biopsy or ovariohysterectomy was performed for histology. Of nine eligible queens, seven were non-pregnant by ultrasound at Visit 2 and two had lost pregnancies by Visit 3. Ovulation was confirmed by serum progesterone concentration in all queens. Ultrasonic appearance of the ovaries and uterus was compatible with a healthy status except for one queen with signs of cystic endometrial hyperplasia (CEH) and pyometra, a follicular cyst in another, and fetal resorptions in two queens. Six cats had histologic lesions of endometrial hyperplasia, including CEH (n=1). Only one cat had no histologic uterine lesions. Bacteria were cultured from vaginal samples in seven queens at Visit 1, (two were non-evaluable), and in five of seven queens sampled at Visit 2. Uterine cultures were negative except for the cat with pyometra. All urine cultures were negative. In summary, the most frequent pathology observed in these infertile queens was histologic endometrial hyperplasia, which can potentially inhibit embryo implantation and healthy placental development. This suggests that uterine disease might contribute substantially to infertility in purebred queens.

A 4-yr-old, male, captive-born African helmeted turtle (Pelomedusa subrufa) was presented for an ocular disorder of 3 days duration. Physical examination showed edema of all limbs and blepharedema of the left eye. Ophthalmic examination revealed severe blepharoconjunctivitis, a large melting corneal ulcer, and stromal densification that prevented evaluation of the anterior chamber. Examination of the right eye was unremarkable. Ultrasonography of the left eye revealed corneal perforation associated with severe anterior uveitis. Enucleation was performed based on the poor prognosis for the eye and the risk of septicemia. Providencia rettgeri was identified from bacterial culture. Fungal culture was negative. Histopathology of the eyeball revealed a corneal perforation associated with edema and heterophilic infiltration of the corneal stroma. Three weeks after surgery, the enucleation wound had healed. Providencia rettgeri has been reported as a rare cause of keratitis in humans. A systematic literature review showed one case of a melting corneal ulcer in an Asian rhinoceros (Rhinoceros unicornis) associated with this infectious agent. This is the first report of corneal perforation associated with P. rettgeri in a reptile.

AbstractRetroperitoneal paragangliomas are rare tumors of the neuroendocrine system. Only a few canine case reports are available with rare descriptions of their imaging features. The objectives of this multi‐center, retrospective case series study were to describe the diagnostic imaging features of confirmed retroperitoneal paragangliomas and specify their location. Medical records and imaging studies of 10 affected dogs with cytological or histopathologic results concordant with retroperitoneal paragangliomas were evaluated. Dogs had a median age of 9 years. Four of them had clinical signs and laboratory reports compatible with excessive production of catecholamines. Six ultrasound, four CT, four radiographic, and one MRI studies were included. The paragangliomas did not have a specific location along the aorta. They were of various sizes (median 33 mm, range: 9–85 mm of length). Masses had heterogeneous parenchyma in six of 10 dogs, regardless of the imaging modality. Strong contrast enhancement was found in all CT studies. Encircling of at least one vessel was detected in six of 10 masses, clear invasion of a vessel was identified in one of 10 masses. In five of 10 cases, the masses were initially misconstrued as lymph nodes by the on‐site radiologist. Retroperitoneal paragangliomas appear along the abdominal aorta, often presenting heterogeneous parenchyma, possibly affecting the local vasculature, and displaying strong contrast enhancement on CT. Clinical signs can be secondary to mass effects or excessive catecholamine production. Underdiagnosis and misdiagnosis of this tumor are suspected as they can be silent, of small size, or confused with other structures.

Ehlers-Danlos syndrome (EDS) is a group of heterogeneous, rare diseases affecting the connective tissues. The main clinical signs of EDS are skin hyperextensibility, joint hypermobility, and skin fragility. Currently, the classification of EDS in humans distinguishes 13 clinical subtypes associated with variants in 20 different genes, reflecting the heterogeneity of this set of diseases. At present, variants in three of these genes have also been identified in dogs affected by EDS. The purpose of this study was to characterize the clinical and histopathological phenotype of an EDS-affected Chihuahua and to identify the causative genetic variant for the disease. The clinical examination suggested a diagnosis of classical EDS. Skin histopathology revealed an abnormally thin dermis, which is compatible with classical EDS. Whole-genome sequencing identified a heterozygous de novo 27 bp deletion in the COL5A2 gene, COL5A2:c.3388_3414del. The in-frame deletion is predicted to remove 9 amino acids in the triple-helical region of COL5A2. The molecular analysis and identification of a likely pathogenic variant in COL5A2 confirmed the subtype as a form of classical EDS. This is the first report of a COL5A2-related EDS in a dog.

OBJECTIVE:To report clinical, surgical, and pathological findings in client-owned rabbits with histologically confirmed appendicitis.ANIMALS:19 rabbits.PROCEDURES:Medical records for client-owned rabbits that had a histologic diagnosis of appendicitis were reviewed.RESULTS:Median age of the rabbits at presentation was 24.0 months (range, 4 to 84 months). Seventeen cases occurred during the summer and fall seasons. Decreased appetite (17/19 rabbits), abnormal rectal temperature (hyperthermia, 9/16 rabbits; hypothermia, 4/16 rabbits), hypocalcemia (8/11 rabbits), and hypoglycemia (7/15 rabbits) were common signs. Abdominal ultrasonography and CT findings were suggestive of appendicitis in 6 of 8 rabbits and in 1 of 2 rabbits, respectively. Of the 6 rabbits that received medical treatment, 3 died at 48 hours, 1 died at 24 hours after hospitalization, and 1 died at 10 days after presentation; 1 rabbit was alive at 1,030 days after presentation. Of the 8 rabbits that underwent appendectomy, 3 died before discharge from the hospital and 1 died 113 days after surgery; 4 rabbits were alive at 315, 334, 1,433, and 1,473 days after presentation. The remaining 5 rabbits either died or were euthanized before treatment could be instituted. In each of the 19 rabbits, the appendix had evidence of severe inflammation with mucosal ulceration, heterophilic inflammation, and necrotic debris.CLINICAL RELEVANCE:For rabbits with decreased appetite and an apparently painful abdomen, hyperthermia, hypocalcemia, or hypoglycemia, appendicitis should be considered as a differential diagnosis. Further comparisons of medical and surgical treatments are required to establish treatment recommendations for rabbits with appendicitis.