Congenital neoplasms are rare and sporadic in cattle and can cause losses due to abortions and perinatal or neonatal deaths. The etiopathogenesis of congenital tumors in bovine fetuses and neonates is largely unknown, and their diagnosis is often challenging. Here we review the literature on congenital tumors in cattle and report 11 additional cases diagnosed at veterinary diagnostic laboratories in Argentina, Uruguay, the United States, and the United Kingdom, namely 4 congenital lymphomas, 3 mesotheliomas, 2 adenomatoid tumors, 1 lymphangioma, and 1 ovarian sex cord-stromal tumor in bovine fetuses and/or neonatal calves. Lymphomas, mesotheliomas, melanomas, and mast cell tumors were reported most commonly in the literature.

Abortion in small ruminants poses a significant economic threat and can have zoonotic risk. Although the association between yersiniosis and reproductive complications is known, systematic studies and case series on abortion in sheep and goats are scarce. Here we describe epidemiologic and pathologic findings in 34 cases of Yersinia pseudotuberculosis – and Y. enterocolitica –associated abortions in sheep and goats, contributing to the understanding of these zoonotic diseases in California. We conducted a 22-y retrospective study to examine microbiologic and pathologic findings in abortion submissions, as well as the geographic and seasonal distribution of the analyzed cases. Yersiniosis-induced abortion was diagnosed in 22 goats and 12 sheep, with all abortions occurring in the last third of gestation. Samples from lung, liver, placenta, and abomasal contents were submitted for aerobic culture; the highest recovery of Yersinia spp. was from abomasal contents. Microscopically, there was severe necrotizing and suppurative inflammation in the lung, liver, spleen, kidney, and, when present, the placenta, with intralesional bacterial colonies. All cases were received from northern and central California in the winter and spring. Our study provides epidemiologic and pathologic features of Yersinia spp.–induced abortions in small ruminants and provides critical data to pave the way for future research, surveillance, and preventive strategies.

Cutaneous neoplasia is among the most common illnesses in dogs and can pose significant risks. Accurate morphological diagnosis of these conditions is vital for effective treatment and management. In this retrospective study, a total of 3746 canine skin biopsies were submitted to a veterinary reference diagnostic laboratory and evaluated using histopathology. The variables assessed included age, sex, breed, lesion, location, and histopathological diagnosis. Non-neoplastic lesions accounted for 61% of all analyzed samples, while neoplastic tumors accounted for 39%. When looking at age, dogs ranging 3–6 years and 7–9 years had at least six times higher risk of developing malignant neoplasia compared to those aged 0–2 years. Among the malignant neoplasms, mast cell tumors, hemangiosarcoma, and squamous cell carcinoma were the most observed, representing 30%, 18%, and 12% of cases, respectively. The breeds most frequently affected by malignant neoplasms included Pit Bull Terriers, Boxers, and mixed breeds, all of which comprised the majority of mast cell tumor cases at 50.54%. These findings are novel in this field and may assist small animal veterinarians in making preliminary diagnoses, while also helping pet owners understand the importance of skin cancer and its early detection.

Confirmation of extracellular amyloid deposition across various animal species and tissue types has been a long-standing challenge in veterinary diagnostic pathology. Transmission electron microscopy (TEM) has historically been used to advance the understanding of amyloid fibril morphology and confirm amyloid fibril deposition when histologic methods provide unclear results. We assessed the feasibility of utilizing TEM for routine confirmation of amyloidosis as an addition to histology. We analyzed ex situ amyloid fibrils with direct, negative-contrast TEM and in situ amyloid fibrils with aldehyde-fixed, plastic-embedding TEM to confirm amyloidosis in a variety of cases in which amorphous extracellular amyloid deposits had been identified by H&E and Congo red staining. We compared the 2 TEM methods and documented amyloid fibril morphology and morphometry in 7 species (goat, guinea pig, kudu, fox, sheep, flamingo, and duck). Ex situ fibrils had helical morphology and widths of 15–18 nm across all species. Fibril crossover distances had more interspecies variation of 60–130 nm, and species could be grouped based on pitch (twist size). Twisting patterns of in situ fibrils could not be visualized, but in situ widths of 10 nm were measured across all species. In 4 different chicken cases, fibrils differing morphologically from amyloid were consistently detected via both TEM methods, suggesting the possibility of a non-amyloid deposit that is commonly diagnosed as amyloidosis based on its histologic appearance. When available, we recommend routine confirmation of amyloid fibril deposition by TEM.

In animals, salmonellosis is seen typically as enteritis and/or septicemia. Subclinical infection also occurs, and outwardly healthy animals can serve as reservoirs of infection. Reports of salmonellosis in elephants are rare, limited to a few serovars, and the gross and microscopic lesions of enteric salmonellosis in this species have not been described in detail. We present here, in 2 elephants in managed care settings, cases of salmonellosis that resulted from infection by Salmonella enterica serovar Muenchen and S. enterica serovar Montevideo, serovars that have not been described previously as the cause of salmonellosis in elephants, to our knowledge. We also review the literature on salmonellosis in elephants. Animal A, an adult Asian elephant that was euthanized because of gastrointestinal hemorrhage, had multifocal, necrotizing, suppurative enterocolitis, and necrotizing gastritis. Animal B, an adult African elephant with chronic, recurrent colic, followed by death, had necrotizing typhlocolitis. The origin of infection was not determined in either case. The animals came from different facilities and did not have a common feed source. Previously reported cases of salmonellosis in elephants were caused by Salmonella Dublin, Salmonella Typhimurium, or Salmonella Enteritidis. The definitive diagnosis of salmonellosis is made based on compatible gross and microscopic lesions, coupled with the detection of Salmonella spp. in the affected tissues. Effective biosecurity should be adopted to minimize the risk of salmonellosis in elephants in managed care.