The biggest fear most dog owners have in the Mediterranean area - including Portugal - is the threat of infection by Leishmaniosis, or leish, as it is referred to, which is a chronic and potentially life-threatening parasitic disease. Although more often found in dogs, the feline version is becoming more and more frequently reported in endemic areas. Infected animals may never lose the disease in their bodies, and relapses are possible. It’s caused by the bite of infected female phlebotomine sandflies, which feed on blood to produce eggs – and with over 90 sandfly species being known to transmit Leishmania parasites, there is no way to know if the one that lands on your pet is infected or not.


Effective prevention is to avoid exposure to sandflies in the first place. They are more active at dusk – so taking your dog out at this time should be avoided, and you should think about keeping your dog indoors at night if possible.


It can take anywhere between three weeks to seven years for clinical symptoms of leishmaniosis to show, but if your pet’s immune system is strong, it’s likely they will never even show symptoms. However, once the immune system fails, your pet will become more and more sick. Incredibly, about half of dogs in Mediterranean areas are estimated to be infected with leish without showing any symptoms. Age, breed, host genetics, nutrition, concurrent diseases, and other factors may influence the progression from infection to clinical disease.


While it isn’t present in the UK, it is found in many countries in Southern and Eastern Europe, so pets that travel there or have lived in these areas are at risk of becoming infected.


Three forms of Leishmaniosis


There are 3 main forms of leish: cutaneous (the most common, usually causing skin ulcers), mucocutaneous (affecting mouth, nose, and throat), and visceral (the most serious form because it is almost always fatal without treatment).


Sandfly Bite

Leishmaniosis is a disease caused by a protozoan (single-celled) parasite carried by the sandfly, and is found most commonly in rural areas in dogs, cats, and some rodents in many parts of the world - and it is an important disease to be aware of because it can be transmitted to humans and if left untreated, can lead to partial or complete destruction of the mucous membranes of the nose and mouth, causing ugly and severe disability.

When dogs become ill with the disease, they often develop skin sores and become poorly. Some might develop kidney failure, but it is possible for infected dogs to become unwell without having any skin issues.


Prevention

The treatment and prevention of this disease rely mainly on chemotherapeutics, which are highly toxic and have an increasing resistance problem. The development of a safe, effective, and affordable vaccine for all forms of vector-borne disease is needed to block transmission of the parasite between the host and vector, but in the meantime, there are several types of collars that may help in repelling these flies, but care must be taken that instructions are followed and replacement is regular as they lose their effectiveness over time.


Diagnosis

In simple terms, blood samples are initially taken, and if necessary, are followed by skin, lymph node and testing of internal organs, which will reveal if the dog is already carrying the disease but maybe not yet showing any signs of infection. Skin infections will become obvious - bumps or lumps that may eventually turn into ulcers that become crust or scabby. These sores are usually painless, but it might take months or years to heal, and will almost certainly leave scars. My own dog was a victim, with a sore that eventually ate away the tip of her ear, but she recovered.

There are vaccines available which reduce the likelihood of your dog developing symptoms if they do become infected, but they will not prevent infection itself but are safe for already infected dogs. Just talking with your vet is the best first step, particularly if you are bringing a pet into Portugal from a leish-free country.


Author

Marilyn writes regularly for The Portugal News, and has lived in the Algarve for some years. A dog-lover, she has lived in Ireland, UK, Bermuda and the Isle of Man. 

Marilyn Sheridan