British resorts could be closed this summer after swarms of large, barrel jellyfish were spotted off the south west coast in recent weeks, and experts are claiming thousands more could potentially be on the way.

Wind-driven currents, an ideal water temperature, a long-term food supply and mass breeding are just some of the reasons why the numbers of jellyfish have continued to rise.

Barrel jellyfish feed entirely on plankton, which means their sting is too weak to harm humans. Nonetheless, VPIS would like to advise pet owners to remain vigilant: keep a look out for the presence of dead, dying or stranded jellyfish which dogs will naturally tend to investigate and/or eat, during walks on the beach.

Jellyfish sting their prey using nematocysts, i.e. stinging structures located in specialized cells called cnidocytes, located on their tentacles. Contact with a jellyfish tentacle can trigger millions of nematocysts to pierce the skin and inject venom, causing pain and swelling. Dead jellyfish can sting for several weeks after death.

VPIS has provided advice on 6 cases of dogs coming in contact with jellyfish since January 2015. The most commonly reported signs are vomiting or retching, oedema (facial, lips, limb, laryngeal), and hypersalivation.

Treatment of oral exposure is essentially supportive with analgesia, antihistamines and steroids; when skin exposure occurs (less common in dogs than humans due to the fur), the following protocol can be followed:

    • Remaining tentacles should be pulled off the skin (not rubbed off) with a towel or stick. Care should be taken not to expose the rescuer/ handler
    • The area should be irrigated with seawater not fresh water
    • Do not rub the area with sand!
    • Chemicals such as alcohol, meat tenderiser, ammonia or baking soda should not be used as they may cause discharge of the nematocysts.
    • Where there is significant exposure and the dog is in distress hot water immersion may be beneficial: immerse the affected area in hot water (about 45ºC) for about 20 minutes (obviously not practical in situ and only reserved for serious cases).

Prophylactic use of antibiotics is not required as a secondary wound infection is a rare complication.

VPIS presented a poster at the 2015 EAPCCT Congress on canine exposure to jellyfish; click HERE to view it.