Spondylitis in a humpback whale (Megaptera novaeangliae) from the southeast Pacific

Abstract

A 7.25 m long male humpback whale (Megaptera novaeangliae) with spondylitis was found beached on August 13, 1994 at Ancon, Ecuador (2°23' S, 80°47' W). The condition involved at least 11 vertebrae, 7 lumbar (L4 to L11) and 4 caudal (Ca1 to Ca4). Partial fusion of vertebrae was observed as a result of intervertebral bony proliferation, likely impeding full motion. The relatively young age of this specimen and the severity of the deformities suggest an infectious, rather than degenerative, process. The gross findings are most consistent with some type of spondyloarthritis. Although this condition has previously been identified in a number of cetacean species, the pathogenesis, population impact and ecologic implications have not been fully assessed. This is the third case described for humpback whales and the first for a humpback whale from the SE Pacific. KEY WORDS: Spondylitis · Humpback whale · Ecuador Resale or republication not permitted without written consent of the publisherDis Aquat Org 75: [259][260][261][262][263][264] 2007 1973). Spondyloarthritis can also lead to irregular bone growth with severe pain and loss of mobility. With the exception of DISH, the other 3 conditions have been documented from cetaceans. MATERIALS AND METHODSIn this report we describe a case of severe vertebral deformities in a 7.25 m beached, dead male humpback whale Megaptera novaeangliae. The animal was initially observed on August 13, 1994 near Ancon, Ecuador (2°23' S, 80°47' W), and the partially decomposed carcass was examined the following day. The size of the Ecuadorian specimen indicates that this individual was probably an undersized yearling (see Stevick 1999) that had completed the first migrating roundtrip between the breeding area in tropical waters and the feeding area located in waters west of the Antarctic Peninsula (Stevick et al. 2004). RESULTSExternally, there was no evidence of trauma or attempted predation that would indicate a specific cause of death, but the carcass was covered by uncharacteristically large numbers of whale lice (Cyamus sp.), an ectoparasite specialized in feeding on whale skin (Slijper 1979). Lice were particularly abundant over the peduncular and genital remnants, giving the skin a pale brown coloration in these areas (Fig. 1).The most significant gross finding involved the musculoskeletal system and was observed during the flensing process to obtain the skeleton 1. A large portion of the lumbar and caudal vertebrae were fused and covered with a thick layer of irregular bone. The vertebral column was sectioned on the beach into several small blocks to facilitate transportation to a nearby area, where the blocks were buried for natural cleaning. Unfortunately, the block with most of the caudal vertebrae was lost during this period, and the condition of the final part of the spine could not be assessed. The remaining affected vertebral segments included 7 lumbar (L4 to L11) and 4 caudal (Ca1 to Ca4) vertebrae, approximately 1.5 m in total length (Fig. 2). There was a block of ...

Skeletal abnormalities in humpback whales Megaptera novaeangliae stranded in the Brazilian breeding ground

“…In fact, like other systems, the skeletal system reacts to injury and is susceptible to circulatory, inflammatory, neoplastic, metabolic and developmental disorders (Rosenberg 2005). Evidence of infectious and degenerative diseases for example, has been inferred through osseous changes in cetaceans (Cowan 1966, De Smet 1977, Morton 1978, Kinze 1986, Kompanje 1995a, 1999, Sweeny et al 2005, Félix et al 2007.…”

“…Spondylo arthritis was suspected to occur in caudal vertebrae of a specimen from Denmark (Kompanje 1999). Severe infectious spondylitis affected 7 lumbar and 4 caudal vertebrae of a 7.25-m-long humpback whale from Ecuador (Félix et al 2007). The goal of the present study was to investigate the occurrence of skeletal pathologic processes in humpback whales, as well as to evaluate their potential to compromise health and contribute to the stranding event or death.…”

“…In fact, like other systems, the skeletal system reacts to injury and is susceptible to circulatory, inflammatory, neoplastic, metabolic and developmental disorders (Rosenberg 2005). Evidence of infectious and degenerative diseases for example, has been inferred through osseous changes in cetaceans (Cowan 1966, De Smet 1977, Morton 1978, Kinze 1986, Kompanje 1995a, 1999, Sweeny et al 2005, Félix et al 2007.Skeletal abnormalities have been documented in several species of cetaceans; however, published information on osseous pathology in humpback whales is scarce. Five single cases have been reported (Stede 1994, Paterson & Van Dyck 1996, Kompanje 1999, Félix et al 2007, Hellier et al 2011.…”

“…Evidence of infectious and degenerative diseases for example, has been inferred through osseous changes in cetaceans (Cowan 1966, De Smet 1977, Morton 1978, Kinze 1986, Kompanje 1995a, 1999, Sweeny et al 2005, Félix et al 2007.…”

Osteological alterations in the tucuxi Sotalia fluviatilis (cetacea, delphinidae)

“…Different events can leave permanent marks on the bones and reveal important aspects of the life history of a particular animal, but it is not always a simple matter to recognize which processes are involved (Simões-Lopes et al, 2008). Bone fractures, pathological processes, malformations, deformities or alterations related to senescence in cetaceans have been noted in the literature by various authors (Purves & van Bree, 1972;de Smet, 1977;Odgen et al, 1981;Kompanje, 1995a;Berghan & Visser, 2000;Montes et al, 2004;Félix et al, 2007;van Bressem et al, 2007;Oremland et al, 2010, Hellier et al, 2011Groch et al, 2012;Marigo et al, 2013), however, there is persistent confusion regarding certain terminology, the causes and biomechanical consequences of such incidents, sometimes leading to the use of the same term for different osteological features (Simões-Lopes et al, 2008).…”