Leishmaniosis is a potentially fatal disease of dogs that can also affect other animals including humans. It is spread between animals by sand flies. Unfortunately, dogs harbor the infection and are at risk in countries around the Mediterranean, including southern France, Italy, Greece, Spain, Portugal, Turkey, and the Middle East. Dogs living in or traveling to these countries with their owners may be exposed to the Leishmania parasite.

Canine Leishmaniosis is caused by a small parasite that lives inside cells. The disease is spread by infected sand flies which pass the parasite from one animal to another when they bite and feed. The disease occurs in warm climates, eg Central and South America, the Middle East and Mediterranean regions. In these areas as many as 4 out of 10 dogs are infected. Dogs traveling into or through these areas can be infected. Sand flies often live in woodland areas but recently they have adapted to survive in areas close to human habitation especially in South America. Sand flies are more common during the warmer months of the year although, with climate change, the seasonal period for transmission is increasing. Most sand flies that spread leishmaniosis are most active (and will bite) between evening and dawn. They are small flies and may not be easily seen.

Most affected dogs have swollen glands (swellings in the armpits, groin, around the throat) although these may not be obvious in long-haired breeds. Dogs may have poor appetite, listlessness, unwillingness to exercise and weight loss. Skin problems are often seen. These may include loss of hair especially around the head and ears, scaly skin, swellings and ulcers on legs, foot pads and other areas including the mouth and tongue. Ulcers and inflamed areas can appear around the lips, nose, eyes and, especially, the tips of the ears. The nails may become very long and brittle. Other signs may be seen depending on the area of the body affected and include lameness, eye problems, bleeding from the nose, drinking or urinating too much, vomiting and/or diarrhea. Joints may also be damaged by the disease and this causes lameness, stiff gait and swollen limbs.

Signs of disease may develop a long time after infection (up to several years) or within a few months of being exposed to an infected sand fly. It all depends on how susceptible your dog is and the number of sand fly bites. You should be concerned and consult your veterinarian if your pet starts to show any of the signs of ill health mentioned above. If you live in an area where leishmania is common then your veterinarian will be familiar with the disease, but if you live in an area, such as the UK, where leishmania is not a common occurrence then it is important to let your vet know if your dog has ever spent time in regions where sandflies and leishmania are endemic - even if this was only for a few days.

More than one test may be necessary to confirm if your dog has active infection or has just been exposed to an infected sand fly bite. Leishmaniosis can be confirmed with one or more of the following tests:

• 1. Looking for the whole Leishmania organism or looking for the Leishmania DNA (PCR testing) in samples from blood, glands, smears from the eyelid, bone marrow or skin biopsies.
• 2. Looking for very high antibody levels in blood.

In dogs that have been imported from endemic regions to countries where Leishmaniosis is not common, diagnosis may be delayed as the disease may not always be considered initially.

Treatment in dogs is much more difficult than in people and the disease in untreated dogs is commonly fatal. Even with current treatments it is still not possible to completely eliminate the parasite. However, treatment can often dramatically reduce the clinical signs of disease and improve a dog's quality of life. However, continued treatment may be needed lifelong in an infected animal to keep the parasite under control. Treatment is not always straightforward. There are licensed drugs in continental Europe for the treatment of leishmaniosis but these may not be available in all regions. In some regions, your veterinarian may have to contact a drug company to import the drug into their region and may also need to obtain permission from the regulator to import the product. Treatment can be expensive and rarely results in a cure. Dogs that look very well can still harbor small numbers of parasites deep in some organs such as the bone marrow. Before treatment your veterinarian will want to check your dog's kidney function, liver function and immune system. The drugs used are very powerful and may produce significant side effects if the disease has already caused kidney or liver damage. If your dog has serious kidney problems, unfortunately the outlook is likely to be poor. The most successful methods of treatment involve using a combination of different drugs.

If you live in or are traveling to a country where leishmaniosis is common then it is important to protect them against biting sand flies. Dogs should be kept in during the evenings (when the flies are most active) and certain insecticides (synthetic pyrethroids) in spot-on and collar formulation with fly repellent activity should be used. None of these products provides 100% protection. Vaccines against leishmania are available in some countries.

Bites from infected sand flies are the major route of transmission of leishmaniosis. Just like dogs, people are usually infected by being bitten by sand flies. If you are visiting an area where leishmania is known to be common it is vital that you apply repellent insecticides on yourself (as well as your dog). There are no published reports of direct infection from an infected dog to a human without a sand fly vector being involved. However, there are reports of transmission of infection from human to human by blood transfusions and contaminated needles. There are also rare reports of transmission from dog to dog without the sand fly vector. Considering this, general advice would be to limit contact between infected dogs and children or adults with a poorly functioning immune system.