Protect Your Dog Against Vector Borne Disease

The Pet Passport Scheme leads many dog owners to believe that because they have followed rigorous veterinary procedures before taking their dog abroad and prior to re-entering the UK, their dog is completely safe from disease.  This is not true.  The Pet Passport Scheme is designed to prevent rabies and other diseases being spread into the UK but it does not rule out the possibility of a dog being infected with disease while it is abroad.

Imported diseases that cause the most concern are those that are transmitted by biting insects known as ‘vectors’.  The most relevant of these infections being Leishmaniosis spread by sand flies, heartworm disease (Dirofilariosis) spread by mosquitoes and Babesiosis and Erlichiosis that are both transmitted by ticks.


A rescue dog in Spain suffering from Leishmaniosis.
Photo by kind permission of dog behaviourist, Peter Singh

Leishmaniosis is caused by an intracellular parasite that is passed into the blood stream of the dog after being bitten by an infected sand fly.  This disease is prevalent in countries worldwide but also in those countries surrounding the Mediterranean basin.  In areas of Spain such as the Balearic Islands and Italy it is believed that as many as 80 to 90% of dogs may be infected.  Some infected dogs may not develop symptoms for months or years but when they do, they can become very poorly indeed.  Commonly they will suffer skin lesions such as alopecia, scaling and ulceration, often affecting around the eyes and ears.  These symptoms may be accompanied by swollen lymph nodes and weight loss. Other signs include swollen spleen, protein in the urine, lameness, eye inflammation and nose bleeds.

Heartworm, as the name suggests is a parasitic nematode worm.  The microscopic larvae are ingested by feeding female mosquitoes in which they develop before being injected into the skin of a canine host as the mosquitoes take a meal about two weeks later.  The infective larvae then migrate and after undergoing a couple of moults they pass to the heart via the venous circulation.  The worms can cause infections of the dog’s heart and pulmonary embolism (blockages within the lungs) and ultimately heart failure. Heartworms can survive up to 5 years.  Countries where this disease is endemic include Northern Italy, Southern Europe, Portugal Spain and Greece as well as the Americas, Africa, Australia and many parts of Asia.  

Both Babesiosis and Ehrlichiosis are transmitted by ticks.  Babesiosis is caused by a small intracellular parasite and Ehrlichiosis by an intracellular bacteria.  Babesiosis causes fever, lethargy, bloody urine, collapse and in the worst case scenario, multiple organ failure.  Ehrlichiosis invades the blood cells and causes fever, depressed bone marrow production, haemorrhaging and death may occur through secondary infection.  Babesiosis has a global distribution and is also found in Northern Europe, Ehrlichiosis occurs worldwide except for New Zealand and Australia.

What measures can you take to protect your dog?

First of all it is a good idea to do some research and find out whether any of these diseases are endemic to the area that you are planning to visit.  The internet is as good a place as any to look! Always speak to your vet 2 or 3 weeks before travelling and he will recommend preventative treatments.  Advantix is a treatment that is often recommended and is especially effective against ticks but also the Scalibor collar is very effective against sand flies and mosquitoes.  The Scalibor collar may not be stocked by some vets in the UK as there is not a big enough demand but the collar can be bought online and in Europe.

Taking pets with you when travelling abroad is a joy but can so easily turn into a tragedy if you do not take suitable precautions.  Safe travelling!

References:

Hillman Timothy J. , and Shaw Susan E. .  Imported vector-transmitted diseases in Dogs.  Irish Veterinary Journal. Volume 63, Number 5
Urquhart G.M., Amour J., Duncan J.L , Dunn A.M , Jennings FW  (1996) Veterinary Parasitology. Second Edition, Blackwell Science: Oxford.

RELATED LINK - CANINE LEISHMANIOSIS: the CaniLeish®  vaccine obtains a European registration.