Dear All,
 
Thanks to everybody who responded to our previous posting concerning the abnormal swelling observed in a young spotted dolphin off La Gomera (Canary Islands). We have received a multitude of comments as well as a variety of ideas and diagnoses, including a conclusive one. Several similar observations were described, involving both spotted dolphin calves in the Azores and the Canaries as well as a juvenile/young adult male grey seal. We have placed some additional images from our colleagues on our website at:
 
http://m-e-e-r.de/index.php?id=458&L=2
 
Potential reasons for the abnormal swelling in the spotted dolphin calf included the following:
-         congenital umbilical hernia
-         contaminants responsible for dysfunction of the endocrine system
-         congested mammary glands
-         a “good slam” causing internal swelling and hemorrhage
-         rudimentary hind limbs
-         some type of tumour
-         parasitic/bacterial infection (crassicauda, brucella, etc.)
 
Moreover, a small animal veterinarian explained that in young cats there is a disease called fibroadenomatous hyperplasia that makes the mammary glands swell quite significantly.
 
Finally, our colleagues from the University of Las Palmas/Gran Canaria (ULPGC) resolved the puzzle by describing a similar case they had a few years ago: A stranded spotted dolphin calf was necropsied and the ULPGC pathologists found the reason to be a bacterial abscess, most probably caused by a (secondary) infection of a Phyllobotrium delfini cyst. This infection could have been caused by an open wound, and the abscess apparently had grown exuberantly so as to cause an obstruction of the ureter, which in turn lead to the death and the stranding of the animal. An image of this animal can be seen following the link above.
 
Thank you all again, I hope this will be of interest to other researchers coming across something similar in the future.
 
Greetings,
Fabian