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A 15-year-old male white Siberian tiger (Panthera tigris altaica) was evaluated for an elevated, ulcerated, cutaneous mass on the right flank. The mass was removed by excisional biopsy and submitted for histopathology. Based on distinct histological features of intracytoplasmic globular material and positive immunohistochemical staining for Melan-A and vimentin, an amelanotic signet-ring melanoma was diagnosed. While in domestic cats this neoplasm is associated with malignancy and a short survival time, the tiger had no local recurrence or related clinical disease approximately 4 years post surgery. Cutaneous melanocytic tumours are rare in big cats, and the findings in this case suggest that amelanotic signet-ring melanoma is not as malignant as its counterpart in domestic cats., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

This report describes the histological and immunohistochemical features of multicentric, benign, epithelial inclusions (BEIs) in a free-ranging, adult, female Risso's dolphin (Grampus griseus). The differential diagnoses included ectopic hamartomatous epithelial inclusions, non-Müllerian choristoma, Müllerian choristoma and low-grade metastatic carcinoma/mesothelioma. The most likely diagnosis of such BEIs was multicentric, embolic, reactive mesothelium, as suggested by cytomorphological and immunophenotypical features of the BEIs, the occurrence of focal pleural rupture and the immunophenotype of the pleural mesothelium. The former represents a pathological condition not previously reported in a marine mammal species, rarely described in animals, and relatively infrequently recognized in man., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

A uterine prolapse associated with a leiomyoma (fibroid) was observed in a live-stranded Atlantic spotted dolphin (Stenella frontalis). A 7 cm segment of the reproductive tract including the cervix, uterine neck and caudal uterine body had intussuscepted and prolapsed into the cranial vaginal vault. In the leading edge of the intussuscepted/prolapsed uterine wall was a 6 × 3 × 3.5 cm leiomyoma expanding the myometrium. The leiomyoma and prolapse were associated with necrotizing exposure endometritis. This is the first report of a uterine prolapse associated with a leiomyoma in a cetacean. This lesion was believed to be the underlying cause of the live stranding., (Copyright © 2015 Elsevier Ltd. All rights reserved.)

Ten cases of adrenal cortex carcinomas with distant metastases were collected as subclinical lesions at slaughter of approximately 14,000 adult cattle. The primary lesion in the adrenal gland and the distant metastases, to either the lung or liver, were characterized by light microscopy and immunohistochemistry. Carcinomas were usually detected by noting metastases in the lungs as polypoid, soft, red or red and yellow masses. All adrenal tumours were unilateral and none were seen in bulls. In six of 10 carcinomas there was gross evidence of invasion of the vena cava via the adrenal vein. Normal bovine adrenal cortex labelled positively with S100, calretinin, α inhibin and melan-A; however, adenomas and seven of 10 carcinomas were labelled best by melan-A and α inhibin. Three carcinomas, grossly identical to the other seven, had numerous calcific granules and a slightly different microscopical appearance. In addition to melan-A and α-inhibin, these variant carcinomas labelled with S100. This variant may be derived from a different layer of the adrenal cortex. Because of the similarity of the bovine and human adrenal cortices, cultures of spontaneously arising bovine adrenal tumours may be a useful resource for study of human neoplasia., (Copyright © 2012 Elsevier Ltd. All rights reserved.)

Sheep are commonly infected with the protozoan parasite, Toxoplasma gondii. Infection may cause early embryonic death and resorption, fetal death and mummification, abortion, stillbirth, and neonatal death. Most sheep acquire T. gondii infection after birth. Recent studies reported that congenital ovine transmission of T. gondii may be more common than previously believed, but these findings are solely based on PCR data and require confirmation using other techniques to verify the findings. In the present study, during the lambing season of 2005 a toxoplasmosis abortion storm occurred in a flock of purebred Suffolk ewes on a farm in Texas. Only 14 healthy lambs were born, and 38 abortuses, mummies and weak or stillborn lambs were delivered. Another 15 fetuses identified by ultrasound were presumably resorbed or were aborted undetected. Antibodies to T. gondii were found in 37 (94.8%) of the 39 ewes and 30 of them had high titers (1:3200 or higher) when tested in the modified agglutination test (MAT). In the 2006 lambing season, two (both with MAT titers of ≥ 3200 in 2005) of 26 ewes delivered T. gondii infected lambs. T. gondii tissue cysts were found histologically in lesions of encephalitis in a lamb from one ewe and viable T. gondii (designated TgShUs55) was isolated from the brain and heart of a lamb from the second ewe. TheTgShUs55 had an atypical genotype using 10 PCR-RFLP markers, and was 100% lethal for Swiss Webster mice, irrespective of the dose or the stage of the parasite inoculated. In subsequent seasons, the ewes lambed normally. The results of the present study support the hypothesis that most sheep that have aborted due to T. gondii develop protection against future toxoplasmosis induced abortion, but the protection is not absolute., (Copyright © 2012 Elsevier B.V. All rights reserved.)

Multiple cysts ranging from 2-111 mm were noted bilaterally in the ovulation fossa of 11 mature Miranda jennets. These ovulation fossa inclusion cysts (OFICs) were lined by a simple low to columnar epithelium that included many ciliated cells. Although most cases were incidental findings, two of the jennets were presented with reduced fertility. Extensive cyst formation could have been responsible for the reproductive problems because they replaced most of the ovarian parenchyma. Due to their close proximity to the ovulation fossa, the OFICs may have mechanically interfered with passage of eggs into the oviduct. OFICs are histologically common in equids, but are reported uncommonly as gross lesions in either mares or jennets. Ovarian inclusion cysts are associated with neoplasia in women; however, these OFICs showed no evidence of epithelial hyperplasia or cellular atypia and no evidence of independent growth, therefore they were considered to be non-neoplastic. The bilateral occurrence and high incidence of OFICs in Miranda jennets, a breed with limited genetic variability, suggests that the lesion has a genetic causation., (Copyright © 2011 Elsevier Ltd. All rights reserved.)

A fibrous band connecting the middle of the free edge (nodulus Arantii) of the non-coronary aortic valve cusp to the ascending aorta just above the level of the non-coronary sinus of Valsalva was observed in an asymptomatic, 11-year-old, male Border Collie. The fibrous band was unrelated to the cause of the death in this dog. Such fibrous bands are usually reported in humans with congenital bicuspid aortic valves. To our knowledge, this is the first report of a fibrous band in the aortic valve in a domestic animal., (Copyright © 2011 Elsevier B.V. All rights reserved.)

Golden hamsters of one common laboratory strain had a high incidence of hydrocephalus internus. When a severity score of hydrocephalus was used, a major autosomal recessive locus could be identified. However, when a binary score (hydrocephalus, no hydrocephalus) was used, no such major locus could be detected and results of test matings were not consistent with Mendelian inheritance. Golden hamsters with severe forms of hydrocephalus had a dorsally compressed and ventrally intact hippocampus. Implications for the behavior and well-being of affected hamsters are unknown but researchers using this strain should be aware of the likely presence of hydrocephalus.

Of 19 adult cows naturally infected with paratuberculosis, 13 were treated with monensin sodium and six remained untreated. At the beginning of the study, the severity of the histological lesions was assessed from biopsy samples of ileum, liver, mesenteric lymph node and rectal mucosa. From the data acquired it was possible to assign the animals so that the lesions in the two groups were similar (P=0. 8323). Monensin was administered in the feed, which contained 147.5 mg/kg, and each treated cow received 450 mg of monensin daily for 120 days. At the end of this period all cows were killed and histopathological findings in the ileum, liver, mesenteric lymph node and rectal mucosa were compared with the initial findings. A scoring system showed that monensin had a beneficial effect in the ileum (P=0.077), liver (P=0.0322) and rectal mucosa (P=0.0578), but under the conditions of the experiment no such effect could be demonstrated in mesenteric lymph node (P=0.3599). There appeared to be an overall effect on all tissues taken together (P=0.1335). The effect of monensin may have been due to both a halting and a reversal of the pathological process. In all but one of the six untreated cows, the lesions worsened during the course of the experiment., (Copyright 2000 Harcourt Publishers Ltd.)

The neonatal abnormalities, treatments and outcomes in a group of 13 cloned transgenic calves and fetuses that progressed into the third trimester of pregnancy are described. From these 13 fetuses, 8 calves were born live, 4 stillborn fetuses were recovered from 3 cows that died 7 d to 2 mo before term, and 1 aborted fetus was recovered at 8 mo gestation. All fetuses and calves were derived from the same male fetal Holstein fibroblast cell line transfected with a beta-galactosidase marker gene. Six calves were delivered by Cesarian section and two by vaginal delivery between 278 and 288 d of gestation. Birth weights ranged from 44 to 58.6 kg. Five of the 8 live born calves were judged to be normal within 4 h of birth based on clinical signs and blood gas measurements. One of these 5 calves died at 6 wk of age from a suspected dilated cardiomyopathy. Three of the 8 calves were diagnosed with neonatal respiratory distress immediately following birth, one of which died (at 4 d of age) as a result of pulmonary surfactant deficiency coupled with pulmonary hypertension and elevated systemic venous pressures. Similar findings of chronic pulmonary hypertension were also observed in 2 of 5 fetuses. Placental edema was present in both calves that later died and in the 2 fetuses with cardiopulmonary abnormalities. Hydrallantois occurred with or without placental edema in 6 cows, and only 1 calf from this group survived. The 6 cows without hydrallantois or placental edema produced 5 live calves and 1 aborted fetus. The cardiopulmonary abnormalities observed in the calves and fetuses occurred in utero in conjunction with placental abnormalities, and it is likely that the cloning technique and/or in vitro embryo culture conditions contributed to these abnormalities, although the mechanism remains to be determined.

This paper describes Neospora caninum-associated hydrocephalus in an aborted Hereford bovine fetus of 7 months' gestational age. Numerous tachyzoites were observed in areas of the cerebrum with lesions of non-suppurative necrotizing encephalitis.

Citrinin (a mycotoxin produced as a frequent contaminant of food and feed by numerous species of Aspergillus and Penicillium fungi) is embryo/fetotoxic and embryocidal in mice and rats. The present study was designed to examine whether the in vivo observed developmental toxicity of citrinin could be recapitulated using the Hydra attenuata (HA) bioassay and then be confirmed in rat whole embryo culture (WEC). Results from the HA assay indicated that the minimal affective concentrations of citrinin required to elicit a toxic response in the adult hydra (MACA) and in the regenerating hydra (MACD) were 30 mg/l and 20 mg/l, respectively. The Hydra developmental hazard index (A/D ratio) was equal to 1.5, classifying citrinin as a coaffective developmental toxin. In WEC, rat embryos were cultured in homologous (rat) serum containing citrinin at various concentrations ranging from 0.0 and 300 micrograms/ml for a period of 45 h. The results indicated a concentration-dependent reduction in yolk sac diameter, crown-rump length, somite number, protein and DNA contents. No embryonic dysmorphogenesis was observed in any treatment group. Histological examination revealed severe diffuse mesodermal and ectodermal necrosis in embryos treated with 250 micrograms/ml citrinin. At lower concentrations of citrinin, embryos were neither grossly nor histologically different from controls. Both the HA and WEC bioassays demonstrated that citrinin is not a primary developmental toxin. The use of HA and WEC bioassays in tandem may facilitate the rapid detection and ranking of the developmental hazards of food and feedborne mycotoxins.

Intravenously administered complete Freund's adjuvant, emulsified in saline, induced a lesion in the porcine lung characterized by a disseminated histiocytic interstitial pneumonia, type II pneumocyte proliferation and granulomatous arteriolitis. In addition, there was a persistent increase in numbers of alveolar macrophages. The lesion was well developed in 7 days. The sequential development and early resolution of the light microscopic lesions was studied for a period of 21 days after inoculation. The administration of Freund's adjuvant induced a spectrum of lesions typical of many forms of interstitial lung diseases of man and domestic animals. The pig is a suitable host for the investigation of the pulmonary inflammatory response and the repair mechanisms involved in chronic lung disease produced by infectious agents or environmental antigens.