Renal accumulation of prooxidant mineral elements and CKD in domestic cats.

Felids have a high incidence of chronic kidney disease (CKD), for which the most common renal lesion is chronic interstitial nephritis (CIN). CIN can be induced by tissue oxidative stress, which is determined by the cellular balance of pro- and anti-oxidant metabolites. Fish-flavoured foods are more often fed to cats than dogs, and such foods tend to have higher arsenic content. Arsenic is a pro-oxidant metallic element. We propose that renal accumulation of pro-oxidant elements such as arsenic and depletion of anti-oxidant elements such as zinc, underpin the high incidence of CIN in domestic cats. Total arsenic and other redox-reactive metal elements were measured in kidneys (after acid-digestion) and urine (both by inductively-coupled plasma-mass spectrometry) of domestic cats (kidneys, n = 56; urine, n = 21), domestic dogs (kidneys, n = 54; urine, n = 28) and non-domesticated Scottish Wildcats (kidneys, n = 17). Renal lesions were graded by severity of CIN. In our randomly sampled population, CIN was more prevalent in domestic cat versus domestic dog (51%, n = 32 of 62 cats; 15%, 11 of 70 dogs were positive for CIN, respectively). CIN was absent from all Scottish wildcats. Tissue and urinary (corrected for creatinine) arsenic content was higher in domestic cats, relative to domestic dogs and wildcats. Urine arsenic was higher in domestic cats and dogs with CIN. Arsenobetaine, an organic and relatively harmless species of arsenic, was the primary form of arsenic found in pet foods. In summary, the kidneys of domestic cats appear to have greater levels of pro-oxidant trace elements, as compared to dogs and wildcats. Since there was no difference in renal arsenic levels in cats with or without CIN, renal arsenic accumulation does not appear a primary driver of excess CIN in cats. Given clear differences in renal handling of pro vs. anti-oxidant minerals between cats and dogs, further in vivo balance studies are warranted. These may then inform species-specific guidelines for trace element incorporation into commercial diets.

A Fibromyxoid Stromal Response is Associated with Muscle Invasion in Canine Urothelial Carcinoma.

Canine urothelial carcinoma (UC) is the most common type of cancer of the lower urinary tract and tends to affect elderly neutered female dogs, with a high predisposition for Scottish terriers. Tumour stroma, inflammation and necrosis are poorly characterized in canine UC and their role as prognostic factors is unknown. The aims of this study were to (1) assess histologically 381 canine UCs, with emphasis on myxoid tumour stroma, inflammation and necrosis and (2) assess possible associations between these features and the available epidemiological data as well as bladder wall muscle invasion. In 103 of 381 (27%) cases, the stroma was mixed collagenous and myxoid (fibromyxoid), which was strongly associated with invasive growth of muscle (P <0.0001). Peritumoural and intratumoural inflammation was present in 308 of 345 (89%) and 287 of 381 (75%) cases, respectively, and was mostly mild and lymphoplasmacytic. One hundred and fifteen of the 381 (30%) cases showed a variable eosinophilic inflammation and 58 of 381 (15%) presented with formations of one or several lymphoid follicles. Twenty-four percent (91 of 381) of cases had tumour necrosis, which was typically mild. In 83 of 91 (91%) cases, the necrosis was comedo-like. Moderate to severe tumour necrosis was associated with the presence of moderate to predominant fibromyxoid tumour stroma (P <0.02). The results of this study indicate that fibromyxoid stroma is common in canine UC and is a strong indicator for invasive growth of muscle, which is consistent with a poor prognosis. Based on histomorphology, tumour necrosis in canine UC is best described as comedonecrosis.

Pulmonary Basaloid Squamous Cell Carcinoma in a Dog.

A 9-year-old neutered male crossbred dog with a 4-week history of progressive vestibulocerebellar signs was presented for necropsy examination. Gross examination revealed neoplastic growth in the lungs, thoracic lymph nodes, left kidney and cerebellum. Microscopically, the tumour consisted of an infiltrative, densely cellular, basaloid epithelial neoplastic growth with extensive areas of abrupt keratinization. Immunohistochemically, neoplastic cells expressed p63 and partially expressed cytokeratins 5/6. Based on these findings, the tumour was diagnosed as a primary pulmonary basaloid squamous cell carcinoma (BSSC) with metastasis to regional lymph nodes, kidney and brain. As far as the authors are aware, this is the first description of BSCC in an animal species.

Sequence and partial functional analysis of canine Bcl-2 family proteins.

Dogs present with spontaneous neoplasms biologically similar to human cancers. Apoptotic pathways are deregulated during cancer genesis and progression and are important for therapy. We have assessed the degree of conservation of a set of canine Bcl-2 family members with the human and murine orthologs. To this end, seven complete canine open reading frames were cloned in this family, four of which are novel for the dog, their sequences were analyzed, and their functional interactions were studied in yeasts. We found a high degree of overall and domain sequence homology between canine and human proteins. It was slightly higher than between murine and human proteins. Functional interactions between canine pro-apoptotic Bax and Bak and anti-apoptotic Bcl-xL, Bcl-w, and Mcl-1 were recapitulated in yeasts. Our data provide support for the notion that systems based on canine-derived proteins might faithfully reproduce Bcl-2 family member interactions known from other species and establish the yeast as a useful tool for functional studies with canine proteins.

Acinar cell carcinoma of exocrine pancreas in two horses.

Two horses were presented with non-specific clinical signs of several weeks' duration and were humanely destroyed due to a poor prognosis. At necropsy examination, both horses had multiple small, white nodules replacing pancreatic tissue and involving the serosal surface of the abdominal cavity, the liver and the lung. Microscopically, neoplastic cells were organized in acini and contained abundant (case 1) or sparse (horse 2) intracytoplasmic zymogen granules. Immunohistochemically, both tumours expressed amylase and pan-cytokeratin, but not insulin or neuron-specific enolase. In case 2, a low percentage of neoplastic cells expressed glucagon and synaptophysin. The presence of zymogen granules was confirmed in both cases by electron microscopy and occasional fibrillary or glucagon granules were observed in cases 1 and 2, respectively. A diagnosis of pancreatic acinar cell carcinoma was established in both horses.

[Tenesmus and stranguria in a heifer caused by a urachal cyst in the bladder wall]. / Tenesmus und Strangurie bei einem Rind infolge einer Zyste in der Harnblasenwand. Ein Fallbericht.

A 10-month-old Brown Swiss heifer was referred to our clinic be- cause of pollakiuria, stranguria and tenesmus. Ultrasonography and endoscopy revealed a cyst-like lesion at the apex of the urinary bladder. The apex of the bladder was surgically removed with the patient in dorsal recumbency under general anaesthesia. Histological examination revealed a cyst lined with urothelium in the wall of the urinary bladder. The heifer was discharged 9 days after surgery. According to the owner's information the animal did not show any clinical signs 6 months later.