Responses to predators of cultured and wild red abalone, Haliotis rufescens, in laboratory experiments

Hatchery-spawned and reared abalone that are placed onto subtidal reefs to enhance native populations often suffer a high mortality. A potential source of mortality is behavioral differences of cultured and wild abalone. Controlled observations and factorial experiments in the laboratory were used to examine abalone behavior and mortality rate due to three predators — crabs, sea stars and lobsters — on small reefs in laboratory tanks. Two abalone types — cultured and wild — and two age/size classes, 0+ (8–20 mm shell length) and 1+ (25–50 mm), were used. Abalone types differed in their movement patterns, with wild animals moving rapidlyto concealed positions within the reefs and most cultured abalones remaining in their original positions for several hours. Over all experiments, there were differences in predation rates by crabs, lobsters and sea stars, with crabs consuming the most abalone and sea stars the least. Significantly more cultured than wild abalone were consumed in an experiment in which different combinations of predators were present. No consistent differences were seen in the consumption of the two size classes of abalone. Animals fresh from the hatchery suffered significantly higher mortality and were more sluggish in their responses to predators than hatchery-reared abalone that had been acclimated to laboratory conditions. The results suggest, however, that cultured abalone may acclimate relatively quickly to a new environment, which may be useful for future attempts at transplanting these animals.     

Epidemiological,pathological and immunohistochemical aspects of 125 cases of feline lymphoma in Southern Brazil

A retrospective study compiling cases of feline lymphoma diagnosed during 12 years (2004‐2016) in Southern Brazil was performed. A total of 125 cases of lymphoma diagnosed in cats were reviewed, and information including age, breed, sex and tumour topography were collected. FeLV and FIV immunohistochemical tests were performed, as well as immunophenotyping of lymphomas. The alimentary form represented the most common presentation (42/125), followed by mediastinal lymphoma (35/125). Out of 125 cases, 79 presented positive retroviral immunostaining in tumour tissue (52 FeLV alone, 14 FIV alone and 13 presented FIV and FeLV co‐infections), 66/125 of the cases were of T‐cell origin and 59/125 of the cases were of B‐cell origin. The median age of cats with T‐cell lymphoma was 120 months (10‐240 months), and 60 months (6‐204 months) for cats with B‐cell lymphoma. The most frequent alimentary tumour presentation was the enteropathy‐associated T‐cell lymphoma (type 1), and the major type of mediastinal tumour observed was diffuse large B‐cell lymphoma. Considering only mediastinal and alimentary lymphomas (n = 77), the prevalence of mediastinal lymphoma in FeLV‐positive cats was 2.21 times higher than the prevalence of this type of tumour in FeLV‐negative cats (P = .036). Mediastinal lymphoma was more frequently observed in younger cats, and the prevalence of mediastinal tumours in these animals was 3.06 times higher than the prevalence of this tumour form in old cats (P = .0125). The present study indicates that retroviral infections still play an important role in the development of feline lymphomas in southern Brazil.     

Pathological and microbiological characterization of mastitis in dairy cows

Mastitis may be caused by a wide range of microorganisms able to induce distinct lesions in mammary tissues. This study aims to characterize the gross and microscopic features of mastitis in dairy cows and to correlate them with the pathogens involved. The udders of slaughtered dairy cows were inspected and milk samples from each mammary quarter or fragments of the parenchyma were sent for microbiological analysis, and tissue collected for histopathological evaluation. A total of 148 cows and 592 mammary quarters were collected. From these, 432 quarters (73%) had mastitis and in 160 (27%), no changes were observed. Mastitis was classified into seven patterns based on the histopathological findings, of which mixed, lymphoplasmacytic, and suppurative mastitides were the most prevalent with 35.9% (155/432), 27.1% (117/432), and 14.3% (62/432) of the cases, respectively. These patterns were associated with the same set of pathogens: Streptococcus spp., coagulase-negative Staphylococcus (CNS), Staphylococcus aureus, Streptococcus agalactiae, Streptococcus uberis, and Corynebacterium bovis. The pyogranulomatous pattern represented 7.2% (31/432) of the cases with distinct distribution based on the agent involved, mostly S. aureus and Nocardia sp. Abscedative mastitis accounted for 6.0% (26/432) of the cases; it was characterized by multiple abscesses in the parenchyma and was mainly caused by Trueperella pyogenes. Necrosuppurative mastitis represented 5.8% (25/432) of the cases which were characterized by severe parenchyma necrosis and were caused by bacteria such as CNS and Escherichia coli. The granulomatous pattern represented 3.7% (16/432) of the cases and was occasionally associated with Mycobacterium sp.