An Indo-Pacific humpback dolphin (Sousa chinensis) severely injured by vessel collision: live rescue at sea, clinical care, and postmortem examination using a virtopsy-integrated approach.

BACKGROUND: Vessel collision induces blunt and sharp force traumas to aquatic animals and is a leading anthropogenic impact affecting cetaceans worldwide. Vessel collision is an important threat affecting vulnerable coastal cetaceans such as the Indo-Pacific humpback dolphins (Sousa chinensis) which reside in coastal waters of Hong Kong amongst heavy marine traffic. CASE PRESENTATION: A severely injured subadult S. chinensis was sighted in the waters off southwestern Hong Kong with four gaping incision wounds on its dorsum. It was in poor body condition and seemed unable to use the fluke effectively. The deepest wound located at the caudal peduncle near the base of the fluke and exposed the underlying fractured caudal vertebrae. The dolphin was monitored in the field over three weeks and eventually captured for medical intervention as veterinary assessment indicated progressive and life-threatening deterioration. During rehabilitation, the dolphin demonstrated initial signs of improvement over the first 36 hours as supported by diagnostic tests but then deteriorated rapidly. It was humanely euthanised after three days of rehabilitation. Postmortem investigation was carried out using virtopsy (postmortem computed tomography and magnetic resonance imaging) and conventional necropsy, with special attention to the traumatic musculoskeletal injuries caused by vessel collision and also revealed acute gastrointestinal compromise and respiratory disease that further hampered the rehabilitation. CONCLUSION: In cetaceans, the prognosis for recovery from injuries caused by vessel collision depends on the extent, location, and gravity of the injuries (i.e., superficial, deep, penetrating, blunt vs. sharp, fresh vs. septic), as well as the health status of the individual and its ability to respond to the insult. Injuries extending deep into the vertebral column may lead to delayed death and associated welfare issues. The prognosis of this case was likely poor given the severity and location of the injuries, but the attempted rehabilitation and postmortem investigation provided valuable insights for clinical management if similar cases are encountered in the future. Being able to non-invasively assess and document traumatic injuries and other pathologies, diagnostic imaging is particularly useful in the clinical assessment and postmortem investigation (virtopsy) of cases with vessel-induced injuries.

Likely Age-Related Hearing Loss (Presbycusis) in a Stranded Indo-Pacific Humpback Dolphin (Sousa chinensis).

The hearing of a stranded Indo-Pacific humpback dolphin (Sousa chinensis) in Zhuhai, China, was measured. The age of this animal was estimated to be ~40 years. The animal's hearing was measured using a noninvasive auditory evoked potential (AEP) method. The results showed that the high-frequency hearing cutoff frequency of the studied dolphin was ~30-40 kHz lower than that of a conspecific younger individual ~13 year old. The lower high-frequency hearing range in the older dolphin was explained as a likely result of age-related hearing loss (presbycusis).

Unilateral ventral strabismus in an aquarium Silver Arowana (Osteoglossum bicirrhosum).

An adult silver arowana (Osteoglossum bicirrhosum) presented with a 2-month history of acute onset ventral strabismus of the right eye associated with a cystic structure overlying the dorsal aspect of the globe. Aspiration of the cyst, removal of redundant conjunctival tissue, and apposition of the surgical edges of the conjunctiva did not correct the strabismus. Magnetic resonance imaging of the head and histopathology of the eye did not reveal significant differences between affected and unaffected eyes except for a more posterior dorsal rectus muscle insertion site in the affected eye. This case report documents and describes a syndrome well known among arowana hobbyists as 'drop eye'.

MANAGEMENT OF OSTEOARTHRITIS IN A GIANT PANDA (AILUROPODA MELANOLEUCA) WITH MULTIMODAL THERAPY INCLUDING AMANTADINE SULPHATE.

In 2002 a 23-yr-old female giant panda (Ailuropoda melanoleuca) presented with left hind limb lameness presumably due to osteoarthritis. For the next five years, arthritic episodes were managed with the nonsteroidal anti-inflammatory drug (NSAID) carprofen at 2 mg/kg p.o. s.i.d., then reduced to 1 mg/kg p.o. s.i.d. and withdrawn. Radiographs revealed osteoarthritis in various joints and lumbar spondylosis. In 2007 glucosamine and chondroitin at 1.65 g p.o. b.i.d. and a polyunsaturated fatty acid at 1 capsule p.o. s.i.d. By 2008, arthritic episodes were becoming more difficult to successfully manage and higher doses and longer durations of treatment with carprofen were needed (2 mg/kg p.o. b.i.d.) and by August 2009 episodic treatment was no longer successful so the carprofen was continued indefinitely at 1 mg/kg p.o. s.i.d. In November 2009 carprofen was increased to 2 mg/kg p.o. b.i.d. An NMDA antagonist amantadine sulphate was trialed and after 10 days at 200 mg p.o. s.i.d. the clinical signs resolved. Since then it has been maintained on carprofen at 1 mg/kg p.o. b.i.d., amantadine sulphate 200 mg p.o. s.i.d. and the neutraceuticals as above with no further relapses of arthritic pain.

Fatal Fusarium solani species complex infections in elasmobranchs: the first case report for black spotted stingray (Taeniura melanopsila) and a literature review.

Fusarium species are environmental saprophytic fungi. Among the many Fusarium species, members of the Fusarium solani species complex (FSSC) are the most prevalent and virulent in causing human and animal infections. In this study, we describe the first case of fatal FSSC infection in a black spotted stingray and three concomitant infections in scalloped hammerhead sharks. In the stingray, cutaneous lesions were characterised by ulcers and haemorrhage of the ventral pectoral fin, or 'ray', especially around the head; while cutaneous lesions in the sharks were characterised by ulcers, haemorrhage, as well as white and purulent exudates at the cephalic canals of the cephalofoil and lateral line. Histological sections of the cutaneous lesions revealed slender (1-4 µm in diameter), branching, septate fungal hyphae. Internal transcribed spacer region and 28S nrDNA sequencing of the fungal isolates from the fish showed two isolates were F. keratoplasticum (FSSC 2) and the other two were FSSC 12. Environmental investigation revealed the FSSC strains isolated from water and biofilms in tanks that housed the elasmobranchs were also F. keratoplasticum and FSSC 12. Fusarium is associated with major infections in elasmobranchs and FSSC 12 is an emerging cause of infections in marine animals. DNA sequencing is so far the most reliable method for accurate identification of Fusarium species.

Possible age-related hearing loss (presbycusis) and corresponding change in echolocation parameters in a stranded Indo-Pacific humpback dolphin.

The hearing and echolocation clicks of a stranded Indo-Pacific humpback dolphin (Sousa chinensis) in Zhuhai, China, were studied. This animal had been repeatedly observed in the wild before it was stranded and its age was estimated to be ~40 years. The animal's hearing was measured using a non-invasive auditory evoked potential (AEP) method. Echolocation clicks produced by the dolphin were recorded when the animal was freely swimming in a 7.5 m (width)×22 m (length)×4.8 m (structural depth) pool with a water depth of ~2.5 m. The hearing and echolocation clicks of the studied dolphin were compared with those of a conspecific younger individual, ~13 years of age. The results suggested that the cut-off frequency of the high-frequency hearing of the studied dolphin was ~30-40 kHz lower than that of the younger individual. The peak and centre frequencies of the clicks produced by the older dolphin were ~16 kHz lower than those of the clicks produced by the younger animal. Considering that the older dolphin was ~40 years old, its lower high-frequency hearing range with lower click peak and centre frequencies could probably be explained by age-related hearing loss (presbycusis).