S. Ferro

Light and Electron Microscopic Analysis of Consecutive Renal Biopsy Specimens From Leishmania-Seropositive Dogs

Canine visceral leishmaniasis frequently causes renal damage that leads to chronic kidney disease. Fifteen dogs seropositive for Leishmania were selected and biopsied before (T0) and 60 days later after (T1) treatment with a specific anti-Leishmania pharmacological agent. Various parameters were selected for evaluating the glomerular and tubulointerstitial damage. At T0, mesangioproliferative and membranoproliferative glomerulonephritis were observed in 6 dogs, chronic glomerulosclerosis in 5, and end-stage kidney in 3; renal tissue from 1 dog was within normal histologic limits. The most frequently observed ultrastructural changes were foot-process effacement, thickening of the basement membranes, and immune deposits. One dog had mesangial immune deposits at T1 that had not been present at T0, so the diagnosis was changed to mesangioproliferative glomerulonephritis. In dogs with end-stage kidney, the number of obsolescent glomeruli and cystic atrophied glomeruli was increased at T1. However, progression of the glomerular lesions was minimal in most dogs. Worsening of tubulointerstitial scores was evident in the dogs with the most severe lesions at the first biopsy. Progression of the tubulointerstitial damage was minimal in the mildly affected dogs, and the interstitial inflammation was abated. In conclusion, renal lesions can progress over a 60-day period in canine leishmaniasis. A longer period between the renal biopsies would be necessary to demonstrate more severe changes. In addition a specific anti-Leishmania treatment could have a significant effect in the early stages of the disease.

Circulating Cell-Free DNA in Dogs with Mammary Tumors: Short and Long Fragments and Integrity Index.

Circulating cell-free DNA (cfDNA) has been considered an interesting diagnostic/prognostic plasma biomarker in tumor-bearing subjects. In cancer patients, cfDNA can hypothetically derive from tumor necrosis/apoptosis, lysed circulating cells, and some yet unrevealed mechanisms of active release. This study aimed to preliminarily analyze cfDNA in dogs with canine mammary tumors (CMTs). Forty-four neoplastic, 17 non-neoplastic disease-bearing, and 15 healthy dogs were recruited. Necrosis and apoptosis were also assessed as potential source of cfDNA on 78 CMTs diagnosed from the 44 dogs. The cfDNA fragments and integrity index significantly differentiated neoplastic versus non-neoplastic dogs (P<0.05), and allowed the distinction between benign and malignant lesions (P<0.05). Even if without statistical significance, the amount of cfDNA was also affected by tumor necrosis and correlated with tumor size and apoptotic markers expression. A significant (P<0.01) increase of Bcl-2 in malignant tumors was observed, and in metastatic CMTs the evasion of apoptosis was also suggested. This study, therefore, provides evidence that cfDNA could be a diagnostic marker in dogs carrying mammary nodules suggesting that its potential application in early diagnostic procedures should be further investigated.

Exocrine Pancreas in Cats With Diabetes Mellitus

Pancreatitis has been described in cats with diabetes mellitus, although the number of studies currently available is very limited. In addition, ketoacidosis has been hypothesized to be associated with pancreatitis in diabetic cats. The aims of the present study were to investigate whether diabetic cats have pancreatitis and to determine if pancreatitis is more frequent with ketoacidosis. Samples of pancreas were collected postmortem from 37 diabetic cats, including 15 with ketoacidosis, and 20 control cats matched for age, sex, breed, and body weight. Sections were stained with hematoxylin and eosin, double-labeled for insulin/CD3, insulin/CD20, insulin/myeloperoxidase, insulin/PCNA, and glucagon/Ki67, and single-labeled for Iba1. A previously proposed semiquantitative score was used to characterize pancreatitis, along with counts of inflammatory cells. Scores of pancreatitis and the number of neutrophils, macrophages, and lymphocytes in the exocrine pancreas did not differ between diabetic and control cats or between diabetic cats with and without ketoacidosis. Of note, PCNA-positive acinar cells were increased (P = .002) in diabetic cats, particularly near islets (P < .001). Ki67-positive acinar cells were increased only near islets (P = .038). Ketoacidosis was not linked to proliferation. The results suggest that histopathologic evidence of pancreatitis may not be more frequent in diabetic cats and that ketoacidosis may not be associated with it at the time of death. Augmented PCNA-positive acinar cells might indicate increased proliferation due to chronic pancreatitis. The reason behind the prevalent proliferation of acinar cells surrounding pancreatic islets deserves further investigation.

A preliminary investigation of the role of the transcription co-activators YAP/TAZ of the Hippo signalling pathway in canine and feline mammary tumours

Breast cancer is the most common cancer in women worldwide. Cancer metastases are responsible for the high mortality rate. A small but distinct subset of cells, cancer stem cells (CSCs), have the capacity to self-renew, initiate tumour formation, and develop metastases. The CSC content in human breast cancer correlates with the Hippo tumour suppressor signalling pathway. Specifically, the activity of YAP/TAZ, transcription co-activators of the Hippo pathway, sustains the self-renewal and tumour-initiation capacities of CSCs. Little is known about YAP/TAZ in canine and feline mammary tumours, which are very common tumours. The preliminary aim of the study was to investigate the expression of YAP/TAZ in canine and feline mammary tumours by Western blot and immunohistochemistry. Increased cytoplasmic and nuclear expression of YAP/TAZ was observed in all carcinomas compared to normal tissues, indicating neoplastic deregulation of the Hippo pathway. Nuclear expression significantly increased in grade III (high grade carcinomas) compared to grade I (low grade carcinomas) tumours, suggesting that YAP/TAZ play a role in the increased aggressiveness of these tumours. Moreover, different scoring systems for immunohistochemical analyses were compared and the H index and the Allred scores were the most significant. In conclusion, YAP/TAZ are expressed in aggressive canine and feline mammary tumours as reported in some human cancers. Further studies might better elucidate the role of the Hippo pathway in prognosis and as a target for new therapies. In addition, tumours in dogs and cats may be a useful model to study this pathway.

Primary Hypothyroidism and Thyroid Goiter in an Adult Cat

A 5-year-old, neutered male domestic shorthair cat was referred for evaluation of suspected hypothyroidism. In the previous 2 months, the owner reported mild lethargy, weight gain with decreased appetite, unkempt hair coat, and an episode of bilateral external otitis that temporarily improved after a 10-day treatment with ear medications containing gentamicin, betamethasone, and clotrimazole; treatment was completed 50 days before presentation. The cat had been slightly overweight for several months before the referring veterinarian was consulted, but more precise information was not available from the owner. The cat was started on a commercial diet to control obesity. One month before admission, the referring veterinarian performed a CBC, serum biochemical profile, and urinalysis, and the results were unremarkable. In addition, serum total thyroxine concentration (TT4) was within normal limits (1.1 lg/dL; reference range, 0.8– 4.7) and free thyroxine concentration (fT4), measured by chemiluminescence immunoassay (CLIA), was low (<3.9 lg/dL; reference range, 9.0–33.5). On admission, the cat was obese (body condition score, 8/9) with a body weight of 7.6 kg, and had an unkempt hair coat with diffuse scaling and hypotrichosis ventrally (Fig 1). On palpation of the thyroid region, bilateral symmetric nodules with a diameter of approximately 2–3 cm each were detected. Based on a dermatologic examination, widespread exfoliative dermatosis and bilateral ceruminous otitis externa were diagnosed. Fungal culture of plucked hairs and scraped scales identified Microsporum canis infection. The thyroid tests were repeated at the same laboratory and results included a low TT4 (<0.7 lg/dL; reference range, 0.8–4.7), low fT4 measured by equilibrium dialysis (<0.4 ng/dL; reference range, 0.7–2.3), and high canine thyroid-stimulating hormone (TSH) concentration (5.6 ng/mL; reference range, <0.5), leading to a diagnosis of primary hypothyroidism. The cat was started on levothyroxine at the dosage of 0.1 mg PO q24h. In addition, topical econazole, q3d and itraconazole, 5 mg/kg PO q24h, were prescribed for the dermatophytosis. To investigate the thyroid gland and identify any ectopic thyroid tissue and to characterize the pituitary gland, computed tomography (CT) of the head, neck, and chest was scheduled 5 days later under general anesthesia, along with surgical excision of a thyroid nodule. Before induction of anesthesia, an electrocardiogram and echocardiography were performed that identified no abnormality. The CT was obtained with helical acquisition using a 4-slice scanner with 1.25 mm slice thickness (acquisition parameters: 120 kV, 160 mAs, 1 pitch). After IV administration of 2 mL/kg iohexol, a dynamic study of the pituitary gland was obtained continuously scanning in sequence from the rostral to the caudal margin of the sella turcica until the contrast

Expression of recipient cytomegalovirus in immunosuppressed and xenotransplanted Macaca fascicularis may be related to more severe gastrointestinal lesions

Xenotransplantation is a potential answer to the current organ shortage, but the risk of infections related to overimmunosuppression is an important parameter that may predict the recipients long‐term survival. Cytomegalovirus (CMV) in xenotransplanted and immunosuppressed primates is a well‐known cause of disease particularly affecting the gastrointestinal (GI) tract and a zoonotic concern.

Carcinosarcoma of the biliary system in a cat

A 12-year-old, mixed-breed domestic cat was diagnosed with a multicystic hepatic mass via ultrasonographic examination and computer tomography scan. The tumor associated with the left medial liver lobe, and connected by a thin stalk to the hilar region, was surgically removed. The mass was firm, encapsulated, mottled white to red black, multinodular, and cystic. Histologic diagnosis was carcinosarcoma supported by positive immunohistochemistry for cytokeratins and vimentin of atypical neoplastic cell populations. On the basis of morphology, the origin was considered to be in the biliary tract. Biliary carcinosarcoma is a rare neoplasm that occurs in people. The epidemiology and risk factors have not yet been determined, and the prognosis is poor except for cases in which curative resection is performed.

Splenitis in 33 Dogs

Splenitis is uncommonly reported in dogs. Herein, the authors describe its prevalence, clinical findings and outcomes, histologic patterns, and causes. Splenic samples of dogs diagnosed with splenitis between 2005 and 2013 were collected and stained with hematoxylin and eosin, Gram, green-Gram, Giemsa, periodic acid–Schiff, and Ziehl-Neelsen. Samples were processed for polymerase chain reaction (PCR) to detect bacteria, fungi, and protozoa (Leishmania infantum, Hepatozoon canis). Thirty-three of 660 splenic samples (5%) had splenitis. Clinical findings and outcomes were available in 19 dogs (58%); 49% had weakness, 33% had fever, and 84% survived. The most frequent inflammatory patterns included purulent splenitis (27%), pyogranulomatous splenitis (24%), and neutrophilic perisplenitis (15%). One dog had a putative diagnosis of primary splenitis; in 8 dogs, microorganisms were identified histologically or by PCR in the spleen without obvious comorbidities. Twenty-four dogs (73%) had concurrent diseases; a permissive role in the development of splenitis was suspected in 21 of these cases. Histologic examination identified the cause of splenitis in 10 dogs. Bacteria were identified by PCR in 23 cases, but the bacteria were confirmed histologically in only 6 of these. Leishmania was detected with PCR in 6 dogs. Leishmania was identified in 1 dog and H. canis in another histologically, but both were PCR negative. Fungi were identified in 8 spleens by PCR and in 1 by histology. This study suggests that splenitis is uncommon in dogs and is frequently associated with systemic diseases. Prognosis is favorable in most cases. Identification of bacteria, fungi, and protozoa in the spleens of affected dogs with PCR should be interpreted cautiously, because the findings are not confirmed histologically in many cases.

Caudal mucogingival lesions secondary to traumatic dental occlusion in 27 cats: macroscopic and microscopic description, treatment and follow-up

The main aim of this retrospective study was to describe clinical and histopathological findings in cats with mucogingival lesions developed at the contact point of the premolar and molar teeth of the opposite quadrant. Cases were retrieved following manual review of the medical records, dental records and photographic documentation of all feline dental patients visited in the period between February 2001 and August 2011. Cats showing different lesions at different times were calculated as multiple cases. A total of 27 cats (31 cases) with 44 lesions (26 proliferations [59%], 11 clefts [25%] and seven foveae [16%]) were included. Mean age at the time of the first visit was 6.6 years. The lesion object of the study was the main reason for presentation in only five cases (16%). Proliferations showed two different histopathological patterns and had characteristics in common with human oral pyogenic granuloma. Successful treatment was achieved in all cases by removing the occlusal contact by dental extraction or coronal reduction, possibly associated with lesion excision. This study underlines the need for a thorough oral examination and evaluation of dental occlusion in all patients. Causes for the development of traumatic occlusion may include an acquired overbite (possibly secondary to selective dental extraction), congenital or post-traumatic malocclusion, abnormal latero-lateral mobility of the mandible, occlusal drift of the premolar and molar teeth, and/or alveolar bone expansion.

The use of contrast-enhanced ultrasonography for the detection of active renal hemorrhage in a dog with spontaneous kidney rupture resulting in hemoperitoneum

Objective To describe the use of contrast-enhanced ultrasonography (CEUS) for the detection of active renal hemorrhage in a dog with spontaneous kidney rupture resulting in hemoperitoneum. Case summary A 9-month-old, sexually intact male Boxer dog presented for acute collapse, abdominal pain, and tachycardia. Physical examination findings were consistent with hypovolemia and acute abdomen. B-mode ultrasonography revealed peritoneal effusion and a right kidney mass. Subsequently, a CEUS study was performed on the right kidney, which demonstrated active hemorrhage from that kidney resulting in both hemoretroperitoneum and hemoperitoneum. At exploratory surgery, ultrasonographic findings were confirmed and a right nephrectomy was performed. Histopathology demonstrated severe parenchymal alterations along with the presence of nematode larvae. Fecal and urine testing for the presence of parasitic ova were negative. Identification of the larvae was inconclusive. At 30 days postoperatively, repeat B-mode ultrasound and clinicopathologic testing was unremarkable. The dog was alive at 1 year postsurgery with no ill effects. New or Unique Information Provided To the authors’ knowledge, this is the first report of CEUS for the detection of active hemorrhage from a kidney resulting in hemoretroperitoneum and hemoperitoneum in a dog. Although rare, the finding of nematode larvae within the renal parenchyma may have been the cause of kidney rupture. Importantly, surgical removal of the kidney was curative. Benign processes causing kidney rupture such as parasitic infestation should be considered in the working diagnosis as related to geographical location.