Studies reveal impact and spread of CVBDs worldwide

The recent changes in travel restrictions between the UK and continental Europe coupled with increases in average temperatures in the UK have potentially dramatically lowered the barriers to new CVBDs entering the UK. The risk of one of these diseases, leishmaniosis, has been studied by the team led by Dr Susan Shaw, University of Bristol, UK, who presented their findings at the CVBD meeting in New York.

Dr Shaw reported on an in-depth study of 257 dogs diagnosed in the UK with confirmed leishmaniosis between 2005 and 2007. However, her laboratory has dealt with over 900 cases since 2000 when the PETS travel scheme was initiated. This is a significant increase from previous studies and a number which they believe to be underestimated based on lack of awareness of the symptomatology in clinical cases and the number of sub-clinically infected dogs entering the UK.

A worrying possibility transmission in the UK is already happening

According to Dr Shaw, "This increased prevalence raises the very real prospect of leishmaniosis becoming established in the UK if the sand fly vector appears in this country. Indeed, there is a worrying possibility that there is already transmission occurring in the UK, as a number of dogs in our study had no history of travel outside the UK at all." More information on Dr Shaw's study can be found at dx.doi.org/10.1016/j.vetpar.2009.03.025.

Further evidence of the risk posed by the movement of dogs within Europe was presented by Dr Torsten Naucke. Dr Naucke's study looked at more than 4500 dogs imported into Germany, and found that nearly one in four (23.4%) were infected with babesiosis, and more than one in ten were infected with leishmaniosis (12.2%) and ehrlichiosis (10.1%). According to Dr Naucke, "Based on these findings the importation of dogs from endemic regions to Germany, as well as travelling with dogs to these regions carries a significant risk of acquiring an infection. We would recommend that pet owners seek the advice of their veterinarians prior to importing a dog from an endemic area or travel to such areas." For more information on Dr Naucke's finding, visit>

Dr Jean-Pierre Dedet shared his group's work on developing the first risk map for canine leishmaniosis in France. Having studied more than 40 years of records, the group was able to establish the major areas of endemicity in France. The largest cluster was found in the southern slopes of the Cevennes Mountains and two regions of the Provence and Maritime Alps; a small reduced cluster was found in the North West of France around Tours. Based on the environment in which these clusters were found, the team led by Dr Dedet has been able, for the first time, to develop a model showing which areas of France are most at risk of leishmaniosis, allowing veterinarians and pet owners to better understand the risks faced by dogs, and to take appropriate preventative measures.

A markedly different picture in the case of domestic dogs

Away from Europe, Professor SungShik Shin of Chonnam National University, Korea, led a study looking at the levels of CVBDs in both rural and urban dogs in Korea, an area that has been little studied in the past. This study looked at hunting dogs in the countryside, and found that more than two in five dogs (40.6%) tested positive for a CVBD. The most common CVBD among these dogs was heartworm (Dirofilaria immitis), with a remarkable 22.3% of working dogs testing positive. The other three CVBDs tested for were also notably common, with Anaplasma phagocytophilum, Ehrlichia canis and Borrelia burgdorferi infection levels of 18.8%, 6.1% and 2.2% respectively. When they looked at urban dogs, the picture was markedly different, with only cases of heartworm being found; however the levels of heartworm were nearly as high in this population as in the rural population at around one in seven dogs (14.6%).

Finally, Dr Edward Breitschwerdt of North Carolina State University, USA, presented a case of bartonella infection in a father and daughter from the USA. This case involved a veterinarian who developed a number of chronic symptoms over a period of years, including arthralgia, progressive weight loss, muscle weakness and lack of coordination. His daughter had recently also developed headaches, muscle pain and insomnia. On investigation, the father and daughter were found to be infected with one species and one sub-species of bartonella which, after extended treatment were eventually eliminated, leading to complete remission of symptoms. "These two cases demonstrate the very real threat posed to humans by CVBDs. It's all too easy to forget that there are many of these diseases that, while not common in humans, can cause significant suffering and even death. It's in part because of this risk to humans that I would encourage all veterinarians to ensure they are educated on the symptoms of CVBDs in dogs, as it is only by protecting dogs that we can protect ourselves," said Dr Breitschwerdt.

The proceedings include all the presentations given at the 5th CVBD World Forum in New York, sponsored Bayer Animal Health, where leading experts in CVBDs from around the world met to share the latest research on these important diseases. Sarah Weston of Bayer Animal Health spoke of the CVBD World Forum, "The CVBD World Forum is another example of Bayer Animal Health delivering on our commitment to improving the understanding and treatment of CVBDs. As we have seen at this meeting, this is an area where knowledge is still rapidly expanding, and we are proud to play our part in helping to bring people together to share information and develop new approaches to the study and prevention of CVBDs".

Source: Bayer HealthCare