Henry's Health

Henry’s life may have been put in danger by digesting food he wouldn’t normally consume, including shark cutlets (cut up by a knife) and cooked prawns.

Around Christmas 2007, Henry vomited a plastic bag and prawn heads - possibly a lost bait bag that had fallen from a jetty or a boat and which Henry had mistaken for food.

Over the next two months Henry continued to vomit intermittently and occasionally had blood in his faeces. . The contents of the vomit confirmed that human feeding was part of the problem.

Occasional vomiting is common in seals and sea-lions and is generally not a concern. Seals regularly vomit food they find hard to digest, such as large fish bones, and squid and octopus beaks. Sea-lions are known to throw up small round rocks called gastroliths, which they swallow to help break down this type of food.

However, the frequency of Henry’s vomiting and the contents of his vomit along with his deteriorating body condition had been a worrying sign and raised the level of concern.

On Friday 15 February 2008, a report was received that Henry was vomiting again and had dark liquid faeces. Dark faeces may be caused by the ink in squid eaten by a healthy sea-lion or may be caused by internal bleeding - another indicator that all may not have been well with Henry.

A group of wildlife officers, veterinarians and sea-lion experts from the Department for Environment and Heritage (DEH), Project Dolphin Safe (PDS), Zoos SA, the South Australian Research and Development Institute (SARDI) and the South Australian Museum (SAM) met and decided that to determine the problem, Henry would need a medical check-up.

It is impossible to conduct a full veterinary assessment on a conscious adult sea-lion, so on Tuesday 19 February, the group met and anaesthetised Henry.

While he was asleep, the zoo veterinarian took blood and faecal samples for analysis and did a full clinical examination. At the same time the SARDI researchers glued a satellite transmitter and depth gauge to his back which would tell them where he is at all times for about the next 45 days. This tracker would be important to establish whether or not Henry was still hunting and eating a natural diet. It would also identify where his important feeding areas are, or whether he had become dependant on humans for his food supply. In addition it would provide a clearer picture of his use of the Adelaide coastline so Henry’s interactions with the public can be better managed. The transmitter was small and did not hurt or inconvenience Henry.

In around 45 days the batteries of the tracking device would go flat and it would have to be removed or it would drop off if Henry naturally shredded his old coat.

Thursday 17 April 2008

Henry’s results from his blood tests on 1 April 2008 have shown that everything is looking good.  His white blood cell count has returned to normal after being very low at his last examination.  This is a good sign that he is on top of whatever infection he may have had going on last time.  

His biochemistry all looks good.  One of his liver enzymes is elevated and may be related to the migration of the microfilaria (heartworm -like parasite) we found in his blood.  This may be endemic in the population but difficult to say without assessing blood from others.  Microfilaria have certainly been reported in Californian sea lions and other pinnipeds but without assessing the adult it is difficult to know the exact species and therefore the lifecycle and pathogenicity. 

With the results from his blood work, improved body condition and reduction in vomiting, it seems he is definitely on the improve.  Lets hope he continues to do well.

All the test results came in and, it would seem that Henry is a fairly normal middle aged male sea lion. He does have some microfilaria in his blood but they are common parasites of seals and sea lions and do not require treatment. On 15 February, there was blood in his faeces, but the sample taken on 19 February was clear. It is quite likely that he has a healing ulcer in his digestive tract perhaps caused by human feeding. On 15 February, a sample of Henry’s urine sample was collected from the pavement. This tested positive for blood but, it is entirely possible that the blood was on the ground, not in Henry’s urine at all. So, apart from being a little bit skinny, as far as the tests were able to tell us, Henry is a normal, middle aged, basically healthy sea lion. No further treatment is required and no other tests will be done. When the tracker was removed, he was anaesthetised again (the glue holding it on is very firm so the fur had to be trimmed to take it off) so some tests were repeated – and came back normal. Right now, the news is all good!