Genital and lingual warts in small cetaceans from coastal Peru

We report on genital warts in dusky dolphins Lagenorhynchus obscurus, long-snouted common dolphins Delphinus capensis, bottlenose dolphins Tursiops truncatus and Burmeister's porpoises Phocoena spinipinnis caught in fisheries off central Peru. Lesions were observed inside the genital slit, on the skin adjacent to it, on the penis and on the vagina. Macro- and microscopical features of the lesions resemble those of benign genital warts associated with papillomavirus infection in humans. Genital warts from L. obscurus and P. spinipinnis contained nuclei which stained positive for genus-specific papillomavirus structural antigens, though weakly in the latter species. These data suggest that papillomavirus(es) may be the etiological agent(s) of the disease. The prevalence of the lesions in 130 small cetaceans was high: 66.7% (confidence interval, CI, 57.0 to 74.0%) in L. obscurus (n = 78), 50% in D. capensis (n = 10), 33% in T. truncatus (n = 9) and 48.5% (CI 33.0 to 64.0%) in P. spinipinnis (n = 33). This suggests a venereal transmission of the disease, as in humans. Sexual variation in wart prevalence was found in L. obscurus and P. spinipinnis with males being 2 and 3 times more infected than females, respectively. No correlation was observed between body length (as a measure of age) and wart prevalence, suggesting that no strong and long-lasting immunity was induced in affected animals or that they may have been infected by different types of papillomaviruses. Lingual tumours were seen in 1 D. capensis

A preliminary note on population structure in eastern South Pacific common bottlenose dolphins, <i>Tursiops truncatus</i>

Previous studies of eastern South Pacific common bottlenose dolphins, Tursiops truncatus, defined offshore and inshore ecotypes in Peru based on cranial and tooth morphology, documented the presence of a single resident inshore community (‘pod-R’) in central-north Chile, and confirmed the presence of offshore bottlenose dolphins off Chile. Here, mtDNA control region (331bp) was examined to evaluate genetic relationships between four geographic areas: inshore pod-R (n=8), Chilean offshore population (n=8), Peruvian inshore (n=3) and offshore (n=12)ecotypes. This is the first genetic analysis of T. truncatus in this ocean basin. Phylogenetic analysis grouped the three Peruvian specimens morphologically identified as inshore ecotype in an independent cluster, supported by 100% bootstrap value. The net genetic distance between Peruvian inshore and Peruvian offshore ecotypes was estimated at 2.9%, and even higher when compared with Chilean bottlenose dolphins. Morphological and mtDNA evidence combined argues for considering inshore and offshore ecotypes as evolutionary significant units, to be managed accordingly. Despite its inshore behavioural ecology, pod-R presented a high divergence from the Peruvian inshore ecotype and a relatively closer affinity with the Chilean offshore stock (3.41% and 0.87% net interpopulational distance, respectively). However, homogeneity tests showed significant genetic differences of pod-R with all other groups, including Chilean offshore. This, combined with a low nucleotide diversity (0.0069) and behavioural observations, suggest that pod-R may be reproductively isolated and active protection measures are recommended. Only one haplotype from a total of 21 was shared by Peruvian and Chilean offshore animals. Their net genetic distance was estimated at 0.024 and no significant differences were found in haplotype frequencies, suggesting a single, wide-ranging ‘Peru-Chile offshore stock’

Evidence of poxvirus in dusky dolphin (<i>Lagenorhynchus obscurus</i>) and Burmeister's porpoise (<i>Phocoena spinipinnis</i>) from coastal Peru

In 1990, 74 dusky dolphins (Lagenorhynchus obscurus) and 10 Burmeister's porpoises (Phocoena spinipinnis) were examined for the presence of hyperpigmented marks and pinhole lesions on the skin (tattoo lesions) at the fishing terminal of Pucusana, central Peru. Prevalences of tattoo lesions were 8.1% and 30% in the dolphins and porpoises, respectively. Intracytoplasmic poxviruses were demonstrated by transmission electron microscopy in ultrathin sections of three of eight samples of infected epidermis from both species. The reason for the negative results in others is unclear but may be related to stages of infection with low virus density or even incorrect classification of some lesions as genuine viral tattoos. An irregular arrangement of tubules on the outer viral membrane, similar to those in orthopoxviruses, was visible in negative contrast preparations for P. spinipinnis. This is the first record of poxvirus in porpoises (Phocoenidae) and also the first report for dusky dolphins, and generally for cetaceans of the southern hemisphere

Descripción y evaluación anatómica de lesiones óseas cráneo-mandibulares en cetáceos odontocetos del mar peruano

A total of 308 skulls and 200 jaws from 20 species and one hybrid of odontocetes cetaceans from the Peruvian Ocean were revised for anatomical description and evaluation of bone lesions. They were grouped into 8 types, plus those at the dental alveoli and osteolitic lesions caused by the nematode Crassicauda sp. From the total bone samples, at least 31.2% showed one type of craneo-mandibular lesion whereas the bottle nosed dolphin (Tursiops truncates) was the most affected. Dental alveoli lesions were found in 13.3% of the samples and bone lesions caused by Crassicauda sp. were in 17.3% of the skulls. The most frequent lesions were hyperostosis and osteolisis, followed by osteomyelitis, malformations and occipitoatlantoaxial ankylosed joints. Adult males showed higher frequency of bone and dental alveolar lesions and is suggested that the latter type of lesions could be associated with severe cases of osteomyelitis and osteolisis at the maxilar and mandibular level. The pterigoid bone was the most affected by the Crassicauda sp. nematode

Epidemiological characteristics of skin disorders in cetaceans from South American waters

We document the macroscopic phenotypic characteristics (relative size, location, pattern, colour, extension), prevalence and evolution of five types of skin disorders of unknown aetiology, including ‘green-brown plaques’ (GBP), ‘orange patches’ (OPA), ‘cutaneous nodules’ (NOD), ‘pale dermatitis’ (PAD) and ‘expansive annular lesions’ (EAL) in five odontocete species (n = 559 individuals) from the Southeast Pacific (n = 230) and Southwest Atlantic (n = 329) oceans. GBP affected two likely-adult Sotalia guianensis traveling side-by-side in a freshwater area of the Cananéia Estuary in August 2009. Low salinity is suggested as predisposing factor. OPA were distinguished in three of 209 (1.4%) free-ranging S. guianensis in Sepetiba Bay, Brazil, during winter months of 2005-2008. Epibiont diatoms are suspected aetiological agents. NOD were chronically present in one male adult Orcinus orca observed off the coast of southern Brazil in 2007-2010. PAD was seen in free-ranging individuals and carcasses of Tursiops truncatus, S. guianensis and Pseudorca crassidens from both the Atlantic and Pacific Oceans in 1992 and in 2004-2009. Prevalence was 1% in 103 S. guianensis from Paranaguá Estuary (Brazil), 2.3% in 222 S. guianensis from Sepetiba Bay and 6.9% in 87 inshore T. truncatus from Paracas Bay, Peru. Although in some cases the lesions covered up to 35-40% of the visible body surface and ulcers may occur there was no evidence of mortality and, in time-series of six individuals, PAD eventually healed. In six T. truncatus and five S. guianensis acutely affected, PAD was associated with minor cutaneous injuries and scars, including tooth rakes, suggesting infection routes for opportunistic pathogens. EAL were noted in a Cephalorhynchus eutropia calf from Palena province, Chile, in 2003 and in a P. crassidens calf washed ashore dead in southern Brazil in 2009. The C. eutropia calf disappeared, and probably died, two weeks after first observation. Prevalence of EAL was 6.7% in 15 C. eutropia in 2002-2004. These data suggest that EAL are potentially lethal in calves. PAD and EAL were primarily seen in cetaceans inhabiting biologically or chemically contaminated nearshore waters. In view of their emergence and occasional severity these disorders should be the subject of systematic monitoring

Microparasites and their potential impact on the population dynamics of small cetaceans from South America: a brief review. Document SC/59/DW8, Scientific Committee, International Whaling Commission, Anchorage, Alaska, 4-14 May 2007

We briefly review the pathology, epidemiology and molecular biology of cetacean viruses (including morbilli, papilloma and pox) and Brucella spp. encountered in South America. Antibodies against cetacean morbillivirus were detected (by iELISAs and virus neutralisation tests) in SE Pacific and SW Atlantic delphinids. Morbilliviruses are possibly enzootic in Lagenorhynchus obscurus and offshore Tursiops truncates from Peru and in Lagenodelphis hosei from Brazil and Argentina, but no morbillivirus antibodies were found in inshore small cetaceans. Papillomaviruses cause genital warts in at least three odontocete species in Peru. Two Phocoena spinipinnis papillomaviruses (PsPVs) were found in warts of Burmeister’s porpoises; one (PsPV-1) was cloned and characterized. Half of porpoises had developed genital warts, while in 10% of males the lesions were sufficiently numerous and severe to at least hamper, if not impede, copulation. High titers of cowpox virus neutralising antibodies were detected in Peruvian D. capensis, T. truncatus, L. obscurus and P. spinipinnis in 1993-1995. The high prevalence of orthopoxvirus neutralising antibodies with high titres indicates common infection by poxviruses antigenically related to cowpox virus, the probable causative agents of tattoo skin disease. Cetacean poxviruses may cause significant mortaliy among neonates and calves unprotected by maternal immunity. In Peru, Brucella spp. antibodies were detected (competitive ELISA) in D. capensis, T. truncatus, L. obscurus and P. spinipinnis. Brucellosis is likely enzootic in the latter two species, and may lead to orchitis and bone lesions in L. obscurus and D. capensis. The enzootic circulation of brucellae in L. obscurus and P. spinipinnis may constitute a measurable limiting factor among the environmental variables affecting population dynamics. Also, widespread Brucella spp. infection in several Peruvian odontocetes has public health implications (zoonosis), considering frequent manipulation of carcases and consumption of meat. Extrinsic anthropogenic factors may not only exacerbate the consequences of viral infections on the health of a particular individual, but also operate at the population level

Tattoo disease of odontocetes as a potential indicator of a degrading or stressful environment: a preliminary report. Scientific Committee document SC/55/E1, International Whaling Commission, May-June 2003, Berlin, Germany

We examined the presence of tattoo lesions in 613 small cetaceans belonging to nine species and originating from the Southeast Pacific Ocean, the Southwest and Northeast Atlantic Ocean as well as from the North, Baltic and Mediterranean Seas. Most of the specimens had been caught in nets or were found stranded in the period 1988-2002. Thirty-five bottlenose dolphins from the Sado estuary, Portugal were photographed alive in 1994-1997. Tattoo lesions were detected in 68 of 196 Lagenorhynchus obscurus, 33 of 54 Delphinus capensis, five of 12 Tursiops truncatus, 57 of 95 Phocoena spinipinnis from Peru as well as in 17 of 35 T. truncatus from the Sado estuary, in two of 10 Stenella coeruleoalba and one of four T. truncatus from the Mediterranean Sea. Prevalence of the disease varied significantly between species in mature specimens but not among immatures. It also varied very significantly between inshore (P. spinipinnis and Sado T. truncatus) and offshore or offshore-neritic (S. coeruleoalba, L. obscurus, D. capensis and Peruvian T. truncatus) odontocetes, being higher in adult specimens of inshore (53.5%) than of offshore (29.7%) taxa. This variation may be caused by immunotoxic environmental pollutants of continental origin like organochlorines. The coastal waters of Peru and the Sado estuary suffer from eutrophication and pollution from various origins. Direct correlation with pollutant loads needs to be investigated