Epidemiology of canine cutaneous round cell tumours on the canary archipelago in Spain.

In this study we undertook a comprehensive analysis of a Pet Tumour Registry of the Canary Archipelago (PTR-CA) in Spain to investigate the epidemiology of canine cutaneous round cell tumours. From a database of 2526 tumours collected from 2003 to 2020, we conducted a longitudinal analysis of the main trends in diagnosis, age, multiplicity and anatomical distribution as well as a case-control study comparing these cases with the contemporaneous canine population of the Canary Archipelago to analyse breed distribution. In line with former studies, we found histiocytomas mostly affect young dogs (2, IQR 1-5) and mast cell tumours affect middle-to-old dogs (8, IQR 6-10) with grade 1 affecting at younger ages (6.5, IQR 6-8) than both grade 2 (8, IQR 6-10 years) and grade 3 (9, IQR 7-11). Histiocytomas and plasmacytomas showed a similar anatomical distribution appearing mainly on the face, head and neck regions while mast cell tumours occur mainly on limbs and trunk. Higher risk for mast cell tumours and histiocytomas were found for Bulldog-related breeds such as Boxer (ORMCT = 23.61, CI95%: 19.12-29.15, ORHCT = 10.17, CI95%: 6.60-15.67), Boston Terrier (ORMCT 19.47, CI95%: 7.73-49.05, ORHCT 32.61, CI95%: 11.81-90.07) and Pug (ORMCT 8.10, CI95%: 5.92-11.07, ORHCT 7.87, CI95%: 4.66-13.28) while Chihuahua dogs showed significantly less risk (ORMCT 0.18, CI95%: 0.09-0.33, ORHCT 0.41, CI95%: 0.21-0.78). Notably, the Canarian Mastiff, a local breed, had a low risk of suffering from a mast cell tumour which raises the question of whether this relates to a genetic peculiarity of this breed or some husbandry and environmental factor.

Epidemiology of canine mammary tumours on the Canary Archipelago in Spain.

BACKGROUND: Mammary gland tumours are the most frequently diagnosed tumours in the female dogs but just a few studies have analysed their epidemiology. Therefore, we set out to describe the epidemiology of canine mammary cancer in the Canary Archipelago, Spain. We analysed a pathology tumour registry (PTR) and identified 7362 samples obtained from 5240 female dogs resident on the Canary Archipelago during an 18-year period (2003-2020). Using a case-control study design, we compared mammary tumour affected dogs with the Canarian canine population registry in order to elucidate the breed associations for these tumours. RESULTS: The frequency of a diagnosis of mammary tumours relative to all tumour diagnoses in female dogs decreased during the study period from 62.7% to 48.9%. Contemporaneously, the proportion of dogs diagnosed with mammary tumours who were also neutered increased from 13.6% to 26.9%. There was a negative correlation (R = -0.84) between these changes. Additional findings were that: the proportion of female dogs diagnosed with multiple tumours increased by 23.5% and that the proportion of malignant tumours 89.2% diagnosed has remained stable through the period. Benign mammary tumours were diagnosed at younger ages (9.2 years old) than carcinomas (9.7 years old) and sarcomas (10.4 years old). Epithelial mammary tumours were diagnosed at younger ages in entire female dogs. Samoyed, Schnauzer, Poodle, German Pinscher and Cocker Spaniel were the breeds with the highest odds-ratios (OR) in comparison with the reference (crossbreeds) while Miniature Pinscher, American Staffordshire Terrier, English Pointer as well as some local breeds such as the Canary Warren Hound and the Majorero had the lowest ORs. CONCLUSIONS: This study provides a description of the changing epidemiology of canine mammary cancer in the Canary Archipelago over the last two decades. We found high rates of CMT with a significant predominance of malignant tumours. Exact risk factors are uncertain, but a combination of environmental, regional socioeconomic affecting human and their pets, and animal management factors are likely to play a part. Specifically, neutering was negatively associated with the proportion of epithelial mammary gland tumours and breeds native to the region were at lower risk of mammary tumours. A deeper analysis of all these factors will facilitate a deeper understanding of the epidemiology of mammary gland tumours in both the canine and the human population.

Budd-Chiari-like pathology in dolphins.

Nearly two decades ago, pathologic examination results suggested that acoustic factors, such as mid-frequency active naval military sonar (MFAS) could be the cause of acute decompression-like sickness in stranded beaked whales. Acute systemic gas embolism in these whales was reported together with enigmatic cystic liver lesions (CLL), characterized by intrahepatic encapsulated gas-filled cysts, tentatively interpreted as "gas-bubble" lesions in various other cetacean species. Here we provide a pathologic reinterpretation of CLL in odontocetes. Among 1,200 cetaceans necropsied, CLL were only observed in four striped dolphins (Stenella coeruleoalba), with a low prevalence (2%, N = 179). Together, our data strongly suggest that CLL are the result of the combination of a pre-existing or concomitant hepatic vascular disorder superimposed and exacerbated by gas bubbles, and clearly differ from acute systemic gas embolism in stranded beaked whales that is linked to MFAS. Budd-Chiari-like syndrome in dolphins is hypothesized based on the present pathologic findings. Nonetheless, further researched is warranted to determine precise etiopathogenesis(es) and contributing factors for CLL in cetaceans.

Study on the Role of Histochemical Stains in Identifying Merkel Cells in Dogs.

Merkel cells (MCs) are neuroendocrine cells involved with tactile sense, growth, differentiation, and homeostasis of the skin as well as in different cutaneous diseases. Specific staining techniques are required for their identification because they are not easily visible in paraffin sections stained with hematoxylin and eosin. The present study assess the histochemical features of the MCs in dogs comparing with those described for other mammals in the literature and with the use of immunohistochemistry. A systematic study of samples from MCs-rich areas from healthy dogs was carried out by use of several histologic stains, including metachromatic staining, silver stains, methylene blue, periodic acid-Schiff stain, and osmium-based staining method. MCs were detected by the Grimelius argyrophilic stain in 86.7% of the specimens. The staining was showed as dark-brown granular cytoplasmic and consistently polarized to the basal cell cytoplasm matching with the cellular distribution of the characteristic neurosecretory granules. Some modifications in the standard staining protocol, including rinsing, silver reimpregnation, and counterstain dye, enhanced the MCs identification in stratified squamous epithelium. When compared with Cytokeratin 20-immunolabeled serial sections several MCs appeared nonstained with the argyrophilic method. These differences in MC numbers between stains were statistically significant. Other histologic stains failed to identify MCs in the specimens. The results of this study indicate that Grimelius argyrophilic stain is a suitable method for demonstration of MCs in the stratified squamous epithelium of skin and mucosa. Discussion on its utility when compared with immunohistochemistry and a review of the scientific literature is also presented. Anat Rec, 302:1458-1464, 2019. © 2018 Wiley Periodicals, Inc.

Prostatic Lesions in Odontocete Cetaceans.

The prostate is the only accessory male genital gland described in cetaceans. Although few studies describe the gross and histologic anatomy of the prostate in cetaceans, there is no information on pathological findings involving this organ. The prostate glands of 45 cetaceans, including 8 different odontocete species ( n = 44) and 1 mysticete, were evaluated. The main pathologic diagnoses were verminous prostatitis, septic prostatitis, viral prostatitis, benign prostatic hyperplasia, and prostatitis of unknown etiology. Verminous prostatitis ( n = 12) was caused by nematodes of the genus Crassicauda, and different presentations were observed. Septic prostatitis, identified in 2 cases, both involved nematode infestation and Clostridium spp coinfection. One case of viral prostatitis was identified and was associated with morbillivirus infection. In prostatitis of unknown cause ( n = 7), varying degrees of prostatic lesions, mostly chronic inflammation, were identified. Impacts at individual levels (eg, localized disease, loss of reproductive capacity) and population levels (eg, decreased reproductive success) are plausible. Our results indicate a high occurrence of prostatic lesions in free-ranging odontocetes. For this reason, the prostate should be routinely inspected and sampled during necropsy of odontocete cetaceans.

Sarcoplasmic masses in the skeletal muscle of a stranded pigmy sperm whale (Kogia breviceps).

We measured the abundance of sarcoplasmic masses within skeletal muscle myocytes of an adult female stranded pigmy sperm whale (Kogia breviceps). The presence of these masses in other species has been reported in association with myopathies, including myotonic dystrophy, the most frequently related pathology. Other histopathologic muscle changes included a high number of internal nuclei, variations in fiber size and shape, and the predominance of type I fibers.

Muscular senescence in cetaceans: adaptation towards a slow muscle fibre phenotype.

Sarcopenia, or senile muscle atrophy, is the slow and progressive loss of muscle mass with advancing age that constitutes the most prevalent form of muscle atrophy. The effects of ageing on skeletal muscle have been extensively studied in humans and laboratory animals (mice), while the few reports on wild animals are based on short-lived mammals. The present study describes the age-related changes in cetacean muscles regarding the three factors that determine muscle mass: fibre size, fibre number, and fibre type. We show that the skeletal muscle fibres in cetaceans change with advancing age, evolving towards a slower muscle phenotype. We suggest that this physiological evolution constitutes an adaptation that allows these marine mammals to perform prolonged, deep dives.

Immunohistochemical localisation of 14-3-3 sigma protein in normal canine tissues.

The 14-3-3 sigma protein, also called stratifin, belongs to the highly conserved family of 14-3-3 acid proteins, which are involved in the modulation of diverse signal transduction pathways. Loss of 14-3-3 sigma expression has been observed in several types of human cancers, suggesting that it may have a role as a tumour suppressor gene. The 14-3-3 sigma protein has been localised in normal human tissues exclusively in various epithelial cell types. The aim of the study was to investigate the expression and the distribution pattern of 14-3-3 sigma by immunohistochemical analysis in normal canine tissues. Immunohistochemical expression of 14-3-3 sigma was demonstrated in several normal canine tissues with some minor differences of distribution pattern compared with human tissues. It appears that 14-3-3 sigma is a very specific epithelial cell marker in normal canine tissues.

Expression of oestrogen and progesterone receptors in canine sebaceous gland tumours.

Sebaceous gland oestrogen alpha (ERalpha) and progesterone (PR) receptor expression was examined immunohistochemically in 26 and 32 dogs respectively with sebaceous gland hyperplasia/adenomas, epitheliomas and carcinomas, and in the glands of 10 healthy controls. The mean percentage of ERalpha positive nuclei in control sebaceous glands was 21.31% compared with 11.5% in hyperplasia/adenoma-type lesions, although these values were not statistically different. In sebaceous gland epitheliomas and carcinomas, positive basal cells represented 7.86% and 3.53% of neoplastic cells respectively and these mean percentages were significantly lower in epitheliomas (P < 0.024) and carcinomas (P < 0.015) than in controls. The mean percentage of PR-positive nuclei in control sebaceous glands was 23.96%, similar to the 22.07% found in hyperplasia/adenoma-type lesions. In sebaceous gland epitheliomas and carcinomas, positive cells were scarce and represented 13.5% and 4.06% of neoplastic cells respectively. Differences in the percentage of positive cells between normal and pathological glands reached statistical significance for carcinomas (P < 0.043). In the control group there was greater PR (P < 0.001) and ERalpha expression (P < 0.014) in sebaceous glands in female dogs. The PR and ERalpha immunoreactivity in each category of neoplastic lesions could not be analysed because sample size was too small but when all the sebaceous gland tumours were grouped and analysed, no sex difference was found. The results suggest that oestrogen and progesterone receptor expression is reduced in some canine sebaceous gland tumours. These changes may represent a contributing factor for tumour growth or simply be a consequence of tumour progression.

Morbillivirus and pilot whale deaths, Mediterranean Sea.

An outbreak of a lethal morbillivirus infection of long-finned pilot whales occurred in the Mediterranean Sea from the end of October 2006 through April 2007. Sequence analysis of a 426-bp conserved fragment of the morbillivirus phosphoprotein gene indicates that the virus is more closely related to dolphin morbillivirus than to pilot whale morbillivirus.

Primary colonic lymphoma.

Surgical resection of primary colonic lymphoma can be an important therapeutic tool. We performed a nonrandomized retrospective descriptive study at the University hospital tertiary care center. From January 1990 to June 2002, a total of 15 patients with primary colonic lymphoma were identified from the tumor registry at University of Alabama at Birmingham and retrospectively reviewed under Institutional Review Board approved protocol. Demographic data, clinical features, treatment method (surgery and/or chemotherapy), recurrence rate, and survival were analyzed. The results are presented as mean +/- standard deviation or median and range. Differences in survival were evaluated by the log-rank test and the interval of disease-free survival was calculated using the Kaplan-Meier method. A P value of <0.05 was considered statistically significant. Main outcome measures included surgical results, morbidity, mortality, and recurrence rate. Mean age was 51.5 years (standard deviation 16.4), 33 per cent were male and 67 per cent were female. Presenting symptoms were diarrhea (53.5%), lower gastrointestinal bleeding (13.3%), and nausea and vomiting (46.7%) secondary to low-grade obstruction. Concomitant colorectal disease was present in one patient with ulcerative colitis. Preoperative diagnosis of lymphoma was made in 13 patients (87%) with colonoscopy and biopsy. CT scan was performed in all patients; and none had radiographic evidence of systemic extension. Only one patient had a history of lymphoproliferative disease and exposure to radiation. The most common disease location was the cecum (60%), followed by the right colon (27%), and the sigmoid colon (13%). The mean lactic dehydrogenase (LDH) value was 214.9 u/L (range 129-309). Thirty-three per cent of the patients had an LDH value that was above the upper normal limit. LDH returned to normal after treatment in all patients. Operations performed consisted of right hemicolectomy (13), total proctocolectomy with ileal J J-pouch (1), and sigmoid colectomy (1). Eighty-seven per cent had negative margins at the time of operation. Twelve patients received postoperative chemotherapy (80%). According to the clinical classification of primary non-Hodgkin lymphoma (NHL) of the gastrointestinal tract (Lugano, 1993) all patients corresponded to stage IE. Mean hospital stay was 6.4 days (range 3-26). There was no surgical mortality and the morbidity rate was 20 per cent (3 patients). One patient had a systemic recurrence (7%) approximately 4 months after surgical resection. Mean follow-up was 31 months (median 2-73). Surgical resection of localized, primary colonic lymphoma provides excellent local disease control and should be considered a primary treatment option. The role of chemotherapy remains controversial depending on the grade, stage, and extension of residual disease.