Page 108 - WSAVA2017
P. 108

An Urban Experience
Dogs that have travelled without protection or those imported from endemic countries should be antibody tested on arrival so their infection status can be monitored, breeding and blood transfusion can be avoided and owners can be prepared for the possibility of disease developing.
Tick borne diseases transmitted by Dermacentor reticulatus and Rhipicephalus sanguineus.
Pets travelling abroad may come into contact with tick-borne diseases transmitted by Rhipicephalus sanguineus. R.sanguineus has traditionally been restricted to warmer climates in the South of Europe but is moving North with untraveled cases of Ehrlichia canis having been reported in France, Switzerland and Austria. Although it is unlikely that R.sanguineus would currently establish outdoor endemic populations in Scandinavia, populations can become established in heated homes. Anaplasma platys, Ehrliciha canis and Hepatozoon canis infection can all present with fever, lymphadenopathy and thrombocytopaenia and should be considered as
a differential in pets presenting with these signs that have travelled in, or been imported from R.sanguineus endemic countries.
Diagnosis can be achieved through blood serology or PCR and treated with doxycycline at 10mg/kg per os sid for 3 weeks. Prognosis is improved with early intervention and if allowed to progress to its chronic form, E.canis is often fatal.
It is essential that pets are treated with an effective tick product during travel, and checked for ticks on return to Scandinavian countries. Checking pets for ticks at least every 24 hours and removing any found with a tick hook will also help to prevent disease transmission. If travelling to R.sanguineus endemic countries, this product should be a licensed pyrethroid repellent as E.canis can be transmitted within hours (Fourie et al, 2013) and should be applied 1 week before travel. Ticks removed should be identified to establish which tick-borne diseases amy have been transmitted. Imported pets should be tested for tick-borne diseases by serology or PCR.
Dirofilaria repens
The mosquito vectors for D.repens are already endemic in Scandinavia. but climate has not been suitable for endemic establishment of the parasite. D.repens appears to have less stringent temperature requirements meaning that it is more likely to establish in Northern Europe (Morgan, 2016). Definitive hosts are carnivores including dogs and cats. Humans can also be infected through being exposed to mosquito bites. Transmission occurs in a similar manner
to D.immitis but with adult worms living in skin nodules
and subcutaneous tissues rather than the cardiovascular system. Infection can be sub clinical or lead to dermatitis and skin nodules. Less commonly, adult worms migrate
to the eyes of the host where they may be visible and may cause conjunctivitis. Prevalence of dirofilariosis in cats tends
to be only one tenth of that in dogs and typically occurs in areas of high canine infection rates.
Diagnosis can be achieved through identification
of microfilariae in the blood or through biopsy and histological examination of skin lesions and nodules. Moxidectin/imidacloprid spot on preparations are licensed for treatment and surgical removal of adult worms is also sometimes required. Cases have already been reported in Norway from dogs imported from Romania (Vatne 2014) and so vigilance for relevant clinical signs is vital so treatment can be initiated before local mosquito populations are exposed to infection.
Linguatula serrata
This parasite known as a ‘tongue worm’, is actually a pentastomid and is now thought to be more closely related to arthropods than true worms. The adult parasite is an elongated tongue-shape and is found
in the nasal cavities or sinuses of dogs and foxes. Infection occurs through the ingestion of nymphs in raw offal of infected intermediate hosts such as ruminants, rabbits and horses. Eggs from the adult parasite are passed in the faeces or nasal secretions of infected dogs and are immediately infective. Adult parasites
are large with females typically 30-130mm in length. Although the closely related L.artica is endemic in Scandinavian reindeer, L.serrata is not thought to be endemic. Imported cases have been identified however, in dogs from Romania where raw meat is routinely fed (Gjerde 2013). Although in endemic countries such
as in the middle East and Eastern Europe, zoonotic infection occurs primarily through the ingestion of
raw or undercooked viscera, with farmers, farm dogs and ruminants all living in close proximity, it can also occur through ingestion of eggs in the environment or
in mucoid nasal discharge. This can lead to a variety
of clinical presentations including naso-pharyngitis, blocked nasal passages, visceral pain and aberrant larval migration to the anterior chamber of the eye (Koehsler et al, 2011).
Rapid diagnosis of infected dogs is therefore important to limit zoonotic risk. Diagnosis can be achieved through microscopic examination of nasal secretions for eggs or endoscopy of the nose and pharynx for adult parasites. Treatment is by surgical removal of worms. Milbemycin oxime also appears to have some efficacy and ivermectin has been used to treat reindeer with L.artica.

   106   107   108   109   110