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An Urban Experience
throughout Northern Europe. PCR is a highly specific test and a sensitive method of diagnosis if synovial membrane or skin samples from the site of the original tick bite are used. PCR from blood or joint fluid however, carries low sensitivity and as a result serology is most commonly used as a diagnostic tool. Detection of antibodies in blood or synovial fluid samples is a highly sensitive and specific method of diagnosis. Results confirm exposure to Borrelia spp exposure and correlate well with clinical infection. As early intervention improves prognosis, positive serology combined with relevant clinical signs is sufficient justification so start antibiotic therapy.
Doxycycline at 10mg/kg per os once daily remains the mainstay of treatment as it is excreted via the faeces, is kidney sparing and may have some joint anti- inflammatory properties. Amoxicillin is as an effective alternative in growing animals. Treatment should be continued for a minimum of 4 weeks to maximise the chances of eliminating infection.
Infection with Babesia spp occurs when the parasite
is transmitted to dogs in the saliva of a feeding tick, occurring approximately 48 hours after the start of
blood feeding (Matjila et al 2004). Transmission has
been reported through blood transfusions and in the case of B.gibsoni through dog bites. The parasite invades red blood cells and are described by their
shape (piroplasms) and their size in relation to the red blood cell (large or small). There are five Babesias in Europe that can infect dogs. The large Babesia vogeli
is of relatively low pathogenicity and is transmitted by Rhipicephalus sanguineus. Cases of babesiosis cause by the small Babesia annae and Babesia gibsoni are sporadic across Europe, with B.gibsoni potentially
being transmitted by Ixodes spp ticks. Babesia microti like organisms (B.vulpes) are thought to be transmitted by Ixodes hexagonus ticks and have been recorded sporadically across Europe, including Scandinavia (Sweden). Their clinical and epidemiological significance is unclear. The most pathogenic Babesia spp endemic to Europe is the large Babesia canis and its distribution is closely linked with its main vector, D.reticulatus. Both B.canis and D.reticulatus are endemic in Northern Europe as far North as Poland, and while not thought
to be endemic in Scandinavia, an untraveled case has been reported in Norway (Øines et al, 2010). Although B.canis was not thought to be endemic in the UK, the presence of D.reticulatus endemic foci in the South West of England and Wales (Smith et al 2012) presented the possibility of B.canis being introduced to the UK and this subsequently occurred in Essex, confirming the potential for the spread of the parasite to new endemic foci (Phipps et al, 2016)
Infection can lead to immune mediated haemolytic anaemia with associated icterus, lymphadenopathy, pyrexia, secondary renal and hepatic disease, and in severe cases, death. Diagnosis can be achieved by demonstration of the parasite in peripheral blood smears stained with Giemsa or Diffquick®. The parasite presents as piriform (pear shaped) organisms, often paired, in the red blood cell, or by PCR on blood. Treatment consists of supportive treatment for anaemia and treatment for the parasite. Blood transfusion may be required if PCV drops below 15% and steroids may be indicated if PCV is slow to respond to treatment. Imidicarb given as 2 doses, 5-6mg/kg IM, given 14 days apart is the most effective drug for elimination of the parasite. Atropine may be required to counteract anti cholinesterase side effects and there is frequently pain at the injection site. Emesis is also sometimes seen in association with injection. If this drug cannot be immediately obtained, clindamycin given at 12.5mg/kg orally twice daily also some efficacy. Either method of treatment is unlikely to eliminate the parasite, leaving infected dogs as sub clinical carriers. As a result, infected dogs may have subsequent relapses and act as potential reservoirs of infection.
Rhipicephalus sanguineus, Anaplasma platys and Ehrlichia canis
Rhipicephalus sanguineus is not currently endemic
in Northern Europe as the climate is currently not favourable for establishment of an endemic population. This tick however, is moving Northwards and can now survive and develop in Belgium, France, the Netherlands and Eastern Europe.
In addition to the potential for house infestation, R.sanguineus also carries a number of tick-borne pathogens with potential pathogenicity for Northern European dogs. These include E.canis and A.platys
Ehrlichia canis is an obligate intracellular gram negative bacteria and the cause of canine monocytic ehrlichiosis. E.canis infects monocytes when introduced to dogs
by feeding R.sanguineus ticks. Larvae and nymphs are infected while feeding on infected dogs and transmit the infection after moulting. Transmission has been demonstrated to take place within 3 hours of tick attachment, much faster than transmission of Lyme disease or babesiosis (Fourie et al 2013).
Clinical signs start with an acute phase consisting
of pyrexia, anorexia and lymphadenopathy. Acute
cases may also present with thrombocytopaenia. A subclinical period follows which may last many months or years. Subsequently, the organism is eliminated or severe chronic disease develops. The prognosis for chronic disease is grave with severe leukopaenia and thromboctopaenia and associated immune suppression and bleeding disorders developing. Ocular and neurological signs may also present in acute and chronic

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