James Barnett

PCB pollution continues to impact populations of orcas and other dolphins in European waters

Organochlorine (OC) pesticides and the more persistent polychlorinated biphenyls (PCBs) have well-established dose-dependent toxicities to birds, fish and mammals in experimental studies, but the actual impact of OC pollutants on European marine top predators remains unknown. Here we show that several cetacean species have very high mean blubber PCB concentrations likely to cause population declines and suppress population recovery. In a large pan-European meta-analysis of stranded (n = 929) or biopsied (n = 152) cetaceans, three out of four species:- striped dolphins (SDs), bottlenose dolphins (BNDs) and killer whales (KWs) had mean PCB levels that markedly exceeded all known marine mammal PCB toxicity thresholds. Some locations (e.g. western Mediterranean Sea, south-west Iberian Peninsula) are global PCB “hotspots” for marine mammals. Blubber PCB concentrations initially declined following a mid-1980s EU ban, but have since stabilised in UK harbour porpoises and SDs in the western Mediterranean Sea. Some small or declining populations of BNDs and KWs in the NE Atlantic were associated with low recruitment, consistent with PCB-induced reproductive toxicity. Despite regulations and mitigation measures to reduce PCB pollution, their biomagnification in marine food webs continues to cause severe impacts among cetacean top predators in European seas.

Contaminants in cetaceans from UK waters: status as assessed within the Cetacean Strandings Investigation Programme from 1990 to 2008.

Since 1990, tissue samples from UK-stranded and -bycaught cetaceans have been available for study of contaminant burdens. These have been used to study spatial and temporal trends in concentrations in UK waters, and to investigate potential associations between contaminants and health status. We describe the current status of cetaceans (primarily harbour porpoises, Phocoena phocoena) in UK waters in relation to pollution. Concentrations of BDEs, HBCD, and the organochlorine pesticides are declining. In contrast, concentrations of CBs have plateaued following earlier reductions due to regulation of use, and further reductions are likely to take decades. Blubber PCB concentrations are still at toxicologically significant levels in many harbour porpoises and regularly occur at even higher levels in bottlenose dolphins and killer whales due to their higher trophic level in marine food chains. Further reductions in PCB inputs into the marine environment are needed to mitigate risk from PCB exposure in these species.

Assessment of antemortem tests used in the control of an outbreak of tuberculosis in llamas (Lama glama)

An outbreak of tuberculosis (TB) caused by Mycobacterium bovis in a llama herd is described. Over a 25-month period, a total of 70 llamas were selected for postmortem examination using four distinct criteria: clinical suspicion of disease (15 animals), positive tuberculin skin test result (three animals), antibody positive using a novel serological test (Rapid Test, 54 animals) and elective cull (five animals). Some animals qualified on more than one criterion. Gross lesions of TB were detected in 15 animals, with lung and lymph node lesions consistently observed. Samples were collected from 14 of 15 animals with visible lesions as well as those with no visible lesions, for histopathology and mycobacterial culture. All 14 llamas with visible lesions had caseonecrotic granulomatous lesions associated with acid-fast bacteria and variable mineralisation, and M bovis was isolated from 13. There were no histopathological lesions of TB in llamas with no grossly visible lesions, and M bovis was not isolated from any of these. The predictive value of suspicious gross lesions at postmortem examination was therefore high in the herd. Molecular typing results indicated that the outbreak was caused by a single strain likely to have originated from a local reservoir, probably cattle or wildlife. Antemortem indicators of infection assisted control of the outbreak, but no single test accurately identified all TB cases. Visible lesions were detected in nine of 15 llamas with clinical suspicion of disease, in two of three that had positive tuberculin skin test results and in 10 of 54 that were antibody positive; there was none (zero out of five) in llamas that were electively culled.

Meningoencephalitis and Arthritis Associated with Brucella ceti in a Short-beaked Common Dolphin (Delphinus delphis)

Brucella species infection in marine mammal species has been reported to have a global distribution. In 2007, the description of Brucella ceti was published and formally adopted for those isolates originating from cetaceans and pathologic lesions similar to those seen in terrestrial mammals infected with Brucella spp. have been associated with its isolation. Brucella ceti infection specific to the central nervous system has been described in two species of cetacean: striped dolphins (Stenella coeruleoalba) in Europe and Costa Rica and an Atlantic white-sided dolphin (Lagenorhynchus acutus) in the UK. We describe the first report, to our knowledge, of B. ceti–associated meningitis and arthritis in a third species, the short-beaked common dolphin (Delphinus delphis), in an animal that stranded in the UK.

Identification of Novel Cetacean Poxviruses in Cetaceans Stranded in South West England.

Poxvirus infections in marine mammals have been mainly reported through their clinical lesions and electron microscopy (EM). Poxvirus particles in association with such lesions have been demonstrated by EM and were previously classified as two new viruses, cetacean poxvirus 1 (CePV-1) and cetacean poxvirus 2 (CePV-2). In this study, epidermal pox lesions in cetaceans stranded in South West England (Cornwall) between 2008 and 2012 were investigated by electron microscopy and molecular analysis. PCR and sequencing of a highly conserved region within the viral DNA polymerase gene ruled out both parapox- and orthopoxviruses. Moreover, phylogenetic analysis of the PCR product clustered the sequences with those previously described as cetacean poxviruses. However, taking the close genetic distance of this gene fragment across the family of poxviridae into account, it is reasonable to postulate further, novel cetacean poxvirus species. The nucleotide similarity within each cluster (tentative species) detected ranged from 98.6% to 100%, whilst the similarity between the clusters was no more than 95%. The detection of several species of poxvirus in different cetacean species confirms the likelihood of a heterogeneous cetacean poxvirus genus, comparable to the heterogeneity observed in other poxvirus genera.

HELICOBACTER CETORUM INFECTION IN STRIPED DOLPHIN (STENELLA COERULEOALBA), ATLANTIC WHITE-SIDED DOLPHIN (LAGENORHYNCHUS ACUTUS), AND SHORT-BEAKED COMMON DOLPHIN (DELPHINUS DELPHUS) FROM THE SOUTHWEST COAST OF ENGLAND

Abstract Helicobacter infection in cetaceans was first reported from the US in 2000 when the isolation of a novel Helicobacter species was described from two Atlantic white-sided dolphins (Lagenorhynchus acutus). Since then, Helicobacter species have been demonstrated in cetaceans and pinnipeds from around the world. Since 1990, the Animal Health and Veterinary Laboratories Agency Polwhele, Truro, has been involved in the UK Cetacean Strandings Investigation Programme to establish the cause of death of cetacean species stranded along the coast of Cornwall, England. We describe the isolation of Helicobacter cetorum in a striped dolphin (Stenella coeruleoalba) and evidence of H. cetorum infection in cetaceans from European waters.

Mycobacterium bovis infection in a grey seal pup (Halichoerus grypus)

Mycobacterial disease has been reported in both free-ranging and captive southern hemisphere pinnipeds in Australasia, South America and Europe. Although isolates in cases published prior to 2001 had biochemical characteristics which suggested Mycobacterium bovis , genetic analyses revealed differences and Cousins and others (2003) demonstrated that these isolates were phenotypically and genetically distinct from M bovis and belonged to a unique member of the Mycobacterium tuberculosis complex, given the name Mycobacterium pinnipedii . M pinnipedii has since been isolated from other southern hemisphere pinnipeds, for example, Kriz and others (2011). This paper describes the isolation and identification of what is believed to be the first confirmed case of M bovis in a pinniped. It was isolated from a grey seal pup ( Halichoerus grypus ) undergoing rehabilitation. The seal was found on the south coast of Cornwall in January 2012. It was estimated to be four months of age and weighed 26 kg. The seal was hospitalised in a facility which rehabilitated up to 50 grey seal pups a year and also held a variety of indigenous and non-indigenous pinniped species, otters, penguins, ponies, goats and sheep. On examination, the most significant findings were one 5 cm long open infected wound on the perineum, puncture wounds over both hocks and a tear in the webbing of the right hind flipper. A two-week course of amoxycillin/clavulanic acid was given (Noroclav, initially at 8.75 mg/kg intramuscular, then at 12.5 mg/kg orally, Norbrook, UK). The wounds healed, but due to persistent neutrophilia (initially 22.95 × 109/l, increasing to 72.25 × 109/l; reference range: 2–12 × 109/l; Barnett and Robinson 2003) and failure to gain weight consistently, a two-week course of enrofloxacin (Enrox, 5 mg/kg orally, Virbac, UK) and one injection of long-acting oxytetracycline (Alamycin LA, 20 mg/kg intramuscular, Norbrook, UK) were then given. Over the next month, the seal developed granulomas …

Spinal aspergillosis in pheasants.

WE would like to raise awareness among colleagues of an apparently rare differential diagnosis for leg paresis in pheasants, detected following a recent outbreak in seven- to 10-week-old pheasant poults. The birds had been bought in as day-old chicks and clinical signs were first seen in birds from six weeks of age. By the time birds were presented for postmortem examination, two different age groups were affected. The seven-week-old birds had been housed in two rearing sheds on shredded cardboard litter since arrival and the corners of the sheds were packed out with wood chippings to prevent birds crowding in the corners. From three weeks of age, they had access to outside runs. The 10-week-old birds were in release pens, with ruts and other uneven areas filled in with wood chips from the same source. The course of disease, reported by the owner and expanded upon at a later site visit, was that affected birds initially became inappetent, indicated by an overall reduction in quantity of feed consumed, and were …

Group B Salmonella in lungworms from a harbour porpoise (Phocoena phocoena).

FURTHER to the paper in Veterinary Record describing the prevalence of a host-adapted group B Salmonella enterica in harbour porpoises ( Phocoena phocoena ) ([Davison and others 2010][1]), we wish to report the isolation of the same group B Salmonella enterica serovar from the lungworm species

Systemic Mucormycosis in a Hooded Seal (Cystophora cristata)

Abstract:  A 4-yr-old male captive hooded seal (Cystophora cristata), previously diagnosed as hypothyroid, died after a 3-wk period of lethargy and inappetance despite treatment that included intramuscular administration of antibiotics and multivitamins. Gross pathologic findings included extensive muscle necrosis over the left flank, an underlying necrotic iliac lymph node, two necrotic pulmonary masses and a necrotic bronchial lymph node. Routine cultures yielded a number of bacterial isolates and a heavy pure fungal growth from the necrotic iliac lymph node; wet preparations of which revealed sporangiophores typical of Mucor sp. Histopathology of necrotic muscle, pulmonary lesions and bronchial and iliac lymph nodes revealed necrosis with a marked pyogranulomatous and eosinophilic inflammatory cell infiltrate and fungal hyphae consistent with a Zygomycete species. This is believed to be the first report of systemic mucormycosis in a pinniped likely to have originated from an injection site reaction.