Occurrence of Pulmonary Arteritis with Lungworm Infections in Gray Seals from New England, 2013-2020

Gray seals (Halichoerus grypus) are a common pinniped species in New England coastal waters. Parasitic infection is an important cause of mortality for this species, and lungworm species are frequently implicated in cases of respiratory infection, especially in pups and weanling seals. The most common of these is Otostrongylus circumlitus, a large nematode found in the bronchi and bronchioles of affected seals. The full life cycle is unknown but its presence in lungs and sometimes pulmonary arteries suggests that migration via arterial circulation occurs. Signs and microscopic findings are widely variable; our cases included dyspnea, bloody mucoid oral and nasal discharge, eosinophilic bronchitis/bronchiolitis, suppurative pneumonia, and pulmonary congestion and emphysema. Recent evidence suggests a possible increase in O. circumlitus respiratory infection among gray seals that includes arterial vasculitis lesions with deposition of Splendore-Hoeppli tissue and infiltrates of eosinophils. We aim to describe and document the occurrence of this lesion in cases of O. circumlitus in the gray seal population on Cape Cod, MA. Necropsy results including gross and histologic examination of lung were compiled for 34 gray seals, with 11 of these being diagnosed with pulmonary nematodiasis. Eight of the diagnosed nematodiasis cases were found to have concurrent arteritis. Work is ongoing to evaluate the changes in both the pathology and prevalence of this pathogen over time

Tetratrichomonas and Trichomonas spp.-Associated Disease in Free-Ranging Common Eiders (Somateria mollissima) from Wellfleet Bay, MA and Description of ITS1 Region Genotypes

During an outbreak of Wellfleet Bay virus (WFBV) in common eiders (Somateria mollissima) from the Cape Cod region of Massachusetts, several birds were diagnosed with trichomonosis consisting of multiple trichomonad species. Six birds were examined, with trichomonads found in ceca in four birds and associated typhlitis in three of these four birds. PCR and DNA sequencing utilizing trichomonad-specific primers targeting the ITS1 region of the ribosomal DNA (rDNA) revealed the presence of Tetratrichomonas gallinarum in the gastrointestinal tracts of five birds and Trichomonas spp. in the livers of two birds, one of which had a dual Te. gallinarum-Trichomonas gallinae infection. Sequence analysis revealed no variation between Te. gallinarum sequences whereas the ITS1 sequences obtained from the other Trichomonas spp. demonstrated the presence of multiple genotypes. One sequence had 100% identity to a Trichomonas sp. previously isolated from a Cooper\u27s hawk (Accipiter cooperii) and the other sequence was 100% identical to a previously described Tr. gallinae isolate obtained from a Pacific Coast band-tailed pigeon (Patagioenas fasciata monilis). These findings suggest Te. gallinarum and other Trichomonas spp. possibly contributed to morbidity and mortality in this species. Furthermore, to the authors\u27 knowledge, this is the first report of trichomonad-associated disease in a free-ranging sea duck

Development, validation, and utilization of a competitive enzyme-linked immunosorbent assay for the detection of antibodies against Brucella species in marine mammals

A competitive enzyme-linked immunosorbent assay (cELISA) was developed by using a whole-cell antigen from a marine Brucella sp. isolated from a harbor seal (Phoca vitulina). The assay was designed to screen sera from multiple marine mammal species for the presence of antibodies against marine-origin Brucella. Based on comparisons with culture-confirmed cases, specificity and sensitivity for cetacean samples tested were 73% and 100%, respectively. For pinniped samples, specificity and sensitivity values were 77% and 67%, respectively. Hawaiian monk seal (Monachus schauinslandi; n = 28) and bottlenose dolphin (Tursiops truncatus; n = 48) serum samples were tested, and the results were compared with several other assays designed to detect Brucella abortus antibodies. The comparison testing revealed the marine-origin cELISA to be more sensitive than the B. abortus tests by the detection of additional positive serum samples. The newly developed cELISA is an effective serologic method for detection of the presence of antibodies against marine-origin Brucella sp. in marine mammals

Occurrence of Pulmonary Arteritis with Lungworm Infections in Gray Seals from Cape Cod, 2013-2020

Gray seals (Halichoerus grypus) are a common pinniped species in New England coastal waters. Parasitic infection is an important cause of mortality for this species, and lungworm species are frequently implicated in cases of respiratory infection, especially in pups and weanling seals. The most common of these is Otostrongylus circumlitus, a large nematode found in the bronchi and bronchioles of affected seals. The full life cycle is unknown but its presence in lungs and sometimes pulmonary arteries suggests that migration via arterial circulation occurs. Signs and microscopic findings are widely variable; our cases included dyspnea, bloody mucoid oral and nasal discharge, eosinophilic bronchitis/bronchiolitis, suppurative pneumonia, and pulmonary congestion and emphysema. Recent evidence suggests a possible increase in O. circumlitus respiratory infection among gray seals that includes arterial vasculitis lesions with deposition of Splendore-Hoeppli tissue and infiltrates of eosinophils. We aim to describe and document the occurrence of this lesion in cases of O. circumlitus in the gray seal population on Cape Cod, MA. Necropsy results including gross and histologic examination of lung were compiled for 34 gray seals, with 11 of these being diagnosed with pulmonary nematodiasis. Eight of the diagnosed nematodiasis cases were found to have concurrent arteritis. Work is ongoing to evaluate the changes in both the pathology and prevalence of this pathogen over time

Partial Replacement of Fish Meal with Soy Protein Concentrate in Diets of Atlantic Cod

In two feeding trials conducted with juvenile Atlantic cod Gadus morhua (initial mean weight = 87.9 or 15.92 g), soy protein concentrate (SPC) was used to replace fish meal in isonitrogenous, isocaloric diets. In the first trial, five experimental diets (47% protein, 15% fat; calculated gross energy = 5,059 kcal/kg) were formulated to replace 28, 60, 80, and 100% of dietary fish meal. In the second trial, three diets were formulated with SPC to replace 0, 25, and 50% of the fish meal in a modified commercial diet for marine finfish (50% protein, 15% fat; calculated gross energy = 4,900 kcal/kg; calculated digestible energy = 3,570 kcal/kg). Upon conclusion of the studies, no differences in survival, growth, hepatosomatic index, or viscerosomatic index were found among the treatment groups. The fish attained mean weights of 162.7 and 39.1 g in the first and second trials, respectively, with specific growth rates of 0.76% and 1.12% and feed conversion ratios of 1.28 and 1.29, respectively. No consistent pattern of enteritis was observed in the histological sections taken from fish in either study. These results indicate that SPC can entirely replace fish meal in diets of juvenile Atlantic cod or can be combined with other common feed ingredients to replace up to 50% of dietary fish meal

Mortality assessment of calf moose (Alces alces) during successive years of winter tick (Dermacentor albipictus) epizootics in New Hampshire and Maine.

Populations within ecological communities constantly fluctuate due to a multitude of interactions that can be influenced by climate change. Moose (Alces alces Clinton, 1822) populations in northern New Hampshire and western Maine, subunits of the largest regional moose population in the continental United States, are suspected to be declining due to increasing frequency of winter tick (Dermacentor albipictus Packard, 1869) epizootics that cause >50% late winter mortality of 9-12 month-old calves. To investigate this hypothesis, we collected general health measurements of calves captured at 2 study sites in January 2014-2016, and subsequently performed field necropsies and histologic examination of tissues of those radio-marked calves that died during winter/spring. At capture, calves (n = 179) were in normal (66%) and thin (32%) physical condition with high infestations of winter ticks. Most (88%) mortalities (n = 125) were associated with moderate to severe infestations of winter ticks. Gross necropsies and histologic examination found high tick infestations, emaciation, anemia, and endoparasitism; lungworm (species of the genus Dictyocaulus Railliet and Henry, 1907) was also found in most (87%) calves. Three consecutive years (2014-2016) of winter tick epizootics is unprecedented in the region, rare in North America, and arguably reflects a host-parasite relationship strongly influenced by climate change at the southern fringe of moose habitat.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author

Partial Replacement of Fishmeal with Soybean Meal and Soy Protein Concentrate in Diets of Atlantic Cod

Juvenile Atlantic cod Gadus morhua (initial weight = 24.1 +/- 1.4 g [mean +/- SE) were fed diets in which fish meal (FM) was replaced with soy protein concentrate (SPC) and soybean meal (SBM) in isonitrogenous, isocaloric diets for 84 d. A standard marine finfish diet (3 mm, 54% protein, 14% fat) was modified to produce four experimental diets in which 50% of FM was replaced with soy at 0:1, 1:1, or 1:2 ratios of SPC: SBM and 100% FM replacement with a 1:1 ratio of SPC:SBM. No differences in mortality or feed intake were detected among treatments, and fish fed the 50% FM replacement diets, in any combination, grew as well or better than the control for all variables investigated. Cod fed the 100% FM replacement diet exhibited the lowest growth and differed from the control with respect to final body weight, growth, specific growth rate, and thermal-unit growth coefficient. No enteritis was observed in histological sections. These results indicate that 100% fish meal replacement is not recommended, but 50% replacement can be used without significant reductions in growth or condition indices

Concurrent Infection of Skunk Adenovirus-1, Listeria monocytogenes, and a Regionally Specific Clade of Canine Distemper Virus in One Gray Fox (Urocyon cinereoargenteus) and Concurrent Listeriosis and Canine Distemper in a Second Gray Fox

One free-ranging Gray fox (Urocyon cinereoargenteus) underwent autopsy following neurologic disease, with findings including morbilliviral inclusions and associated lesions in numerous tissues, adenoviral intranuclear inclusions in bronchial epithelial cells, and septic pleuropneumonia, hepatitis, splenitis, and meningoencephalitis. Molecular diagnostics on fresh lung identified a strain within a distinct clade of canine distemper that is currently unique to wildlife in New England, as well as the emerging multi-host viral pathogen skunk adenovirus-1. Bacterial culture of fresh liver resulted in a pure growth of Listeria monocytogenes, with whole genome sequencing indicating that the isolate had a vast array of antimicrobial resistance and virulence-associated genes. One year later, a second fox was euthanized for inappropriate behavior in a residential area, and diagnostic workup revealed canine distemper and septic L. monocytogenes, with the former closely related to the distemper virus found in the previous fox and the latter divergent from the L. monocytogenes from the previous fox