Feline straelensiosis: Clinical and histopathological description of a case and first genetic characterisation of Straelensia cynotis

Straelensia cynotis is a trombidioid mite that causes painful, usually nonpruritic nodular dermatitis mainly in the dorsal region of dogs. This case report describes the first observation of feline straelensiosis in Europe with clinicopathological findings. Molecular characterisation of the parasite was performed and compared with mites collected from dogs.

Straelensiosis in dogs: a newly described nodular dermatitis induced by Straelensia cynotis

A distinctive nodular dermatitis induced by Straelensia cynotis, a newly described trombidioid larval mite which resides in hair follicles, was identified in 12 dogs living in France. They all had scattered, small (1 to 3 mm in diameter), pale, firm skin nodules, variable in distribution but always affecting the dorsal regions of the head and trunk; they were distributed over the whole body of seven of the dogs. The animals were otherwise healthy except for three severely infested fox terriers which had a decreased appetite, were lethargic, and whose skin nodules were painful to the touch. The nodules did not induce pruritus. The lesions usually began as erythematous papules which developed into firm pale nodules. The dermatitis resolved within two to 12 months. Topical acaricides were ineffective but the skin nodules regressed after treatments with systemic avermectins. Histologically, each nodule was composed of a dilated follicular ostium containing a well-preserved larval mite, and showed a pseudoepitheliomatous follicular hyperplasia and an abundant perifollicular mucinosis. The larvae were identified as belonging to the genus Straelensia (Acari: Leeuwenhoekiidae). It was clearly established that the three fox terriers had become infested within a fox's den. The nymphs and adults of this species of mite are believed to live in foxes' dens; foxes are considered to be the natural host for the larval stage, and dogs a permissive but occasional host.

Multiple pigmented cutaneous papules associated with a novel canine papillomavirus in an immunosuppressed dog

Cutaneous papillomavirus infection was diagnosed in a 6-year-old female Boxer dog that was under long-term corticosteroid therapy for atopic dermatitis. Multiple black, rounded papules were present on the ventral skin. Spontaneous regression occurred within 3 weeks after cessation of corticosteroids. Histologically, the lesions consisted of well-demarcated cup-shaped foci of epidermal endophytic hyperplasia with marked parakeratosis. In the upper stratum spinosum and in the stratum granulosum, solitary or small collections of enlarged keratinocytes were observed with basophilic intranuclear inclusion bodies and a single eosinophilic fibrillar cytoplasmic inclusion. Ultrastructurally, viruslike particles (40-45 nm in diameter) were observed within the nucleus, free or aggregated in crystalline arrays. Undulating fibrillar material, thought to be a modified keratin protein, was observed in the cytoplasmic inclusion. Immunohistochemistry, restriction enzyme analysis, and molecular hybridization experiments indicated that these distinctive clinical, histologic, and cytologic features were associated with a novel canine papillomavirus.

Characterization of the arteritis induced by infusion of rats with UK-61,260, an inodilator, for 24 h. A comparison with the arteritis induced by fenoldopam mesylate

Administration of fenoldopam mesylate (FM), a dopaminergic agonist, or of cyclic cAMP phosphodiesterase inhibitors (PDE III), for example theophylline and caffeine, induces arteritis in the rat. In this study we characterized the arteritis induced by UK-61,260, an investigational inotropic agent with vasodilatory properties which displays an inhibitory action on cyclic AMP phosphodiesterase, in comparison with lesions induced by FM. The compounds were administered to Sprague-Dawley rats by intravenous infusion over 24 h (FM and UK-61,260), orally or subcutaneously (UK-61,260); the rats were killed and necropsied for pathological examination at various times between 0 h and 28 days post-infusion. Infusion of UK-61,260 at doses of 100, 300 or 400 mg/kg produced arteritis mainly in the mesenteric arteries and occasionally in the renal, pancreatic, gastric and coronary arteries. There were no arterial lesions after infusion of 30 mg/kg, or after administration of 30, 100 or 200 mg/kg per day subcutaneously for 7 days, or after acute administration of 100, 300, 400 or 600 mg/kg orally. Infusion of rats with 72 or 144 mg/kg FM produced arteritis over a wider range of tissues than did UK-61,260. However, the arterial lesions produced by infusion of either drug have the same initial aspect and a similar evolution with time. Immediately after the end of the infusion, minimal necrosis and haemorrhage occurred in the media only, without involvement of the endothelium or the perivascular space. This indicates that the media of the artery is the primary site of injury. The lesions seen 1 and 3 days post-infusion were characterized by severe medial necrosis and haemorrhage with perivascular acute inflammation and appeared macroscopically as haemorrhagic spots on the vessels. On days 7, 14 and 28 post-infusion, no medial necrosis or haemorrhage were present, while perivascular chronic inflammation and moderate smooth muscle hyperplasia were seen. It appeared, therefore, that the lesions underwent repair in 28 days, but footprints of the damage were still present 28 days post-infusion. The similarity between arteritis induced in rats by fenoldopam or by UK-61,260, at doses inducing PDE III inhibition, is consistent with the view that they have a similar pathogenesis. In our view it is probable that these pharmacologically and chemically distinct drugs trigger an increase in intracellular levels of cAMP which in turn triggers vascular damage. The arterial changes observed in the current study after acute administration may explain the increased incidence of polyarteritis nodosa occurring in long term toxicity studies with FM or PDE III inhibitors.

Pseudohyperparathyroidism in a mare associated with squamous cell carcinoma of the vulva

An 18-year-old Appaloosa mare was examined because of squamous cell carcinoma of the vulva, anorexia with pronounced weight loss, and hypercalcemia. The tumor had developed rapidly over a period of 3 months and externally extended ventrally involving the perineum and the dorsal aspect of the udder. Necropsy examination demonstrated a large primary squamous cell carcinoma of the vulva, perineum, and mammary gland with metastases to the supramammary, sublumbar, deep inguinal, and mediastinal lymph nodes. No gross renal lesions were observed and, histologically, there was only mild vacuolation of renal tubular epithelium. Based on the normal concentration of serum parathyroid hormone, the absence of evidence of hypervitaminosis D, and normal renal function, a diagnosis was made of hypercalcemia of malignancy or pseudohyperparathyroidism. The mechanism responsible for hypercalcemia was not determined, but the histologic type of the neoplasm and the clinical course suggested possible production of a humoral hypercalcemic factor by the neoplasm, similar to that demonstrated in certain types of human squamous cell carcinoma.