In my last article I introduced members to the Pet Travel Scheme, this article concentrates not only on tick-borne diseases in the UK but also what may potentially be imported from overseas.
Ticks are arthropods (of the class Arachnids – as are spiders). There are two main species native to the UK the Sheep Tick (Ixodes ricinus) and the Marsh Tick (or ornate cow tick) (Dermacentor reticulates). Another tick, the Brown Dog Tick (Rhipicephalus sanguineus) is of importance as it may carry a human disease called Mediterranean Spotted Fever if dogs pick it up on their travels via the PETS scheme – this is one of the reasons why I recommend all travelling pets are be treated with effective tick-control before re-entering the UK.
Where and when do ticks live?
Ticks like warmth and humidity. We find them in grassland, scrub and shrubs where they lie in wait for a passing host. In the UK they are most active between March and November.
Ticks and disease
For a tick to transmit disease it must first feed on an infected host – they suck their blood with penetrating mouthparts. When full the tick falls off the host to the ground where it will develop to the next stage in its life-cycle, it will then infest another animal by feeding on it. A tick has a slow life cycle, sometimes taking four years to complete from egg to adult, the host gradually increasing in size. The larvae may feed on hedgehogs and rodents, the nymphs on rabbits and the adults on sheep, deer, our dogs and us humans.
Lyme disease (Borreliosis) in dogs and people
This is caused by bacteria that are carried by ticks. The signs of this disease signs are intermittent lameness, swollen joints, lethargy and fever. These symptoms can become severe and can even cause death. It is most important for all owners to be aware that ticks can transmit this disease to dogs and people in this country and the matter of using effective tick control cannot be taken lightly.
Ehrlichiosis in dogs and people
Although not common in the UK it is often seen in southern Europe, Africa, and the USA. It is caused by a Rickettsial bacterium which affects certain blood cells and may cause dogs to suffer from a fever, anorexia, weight loss, stiffness and prolonged bleeding. It can be passed to humans if we are bitten by an infected tick.
Babesiosis
Babesia is a protozoan parasite carried by Dermacentor and Rhipicephalus ticks. The Dermacentor ticks have been found on cattle in the south of England and the Rhipicephalus has been identified in dogs in quarantine kennels. Babesiosis is serious, causing a loss of appetite, fever, anaemia, fatigue and discolouration of urine. It is potentially fatal if left untreated and can also affect humans. Fortunately, however, it does not normally occur in the UK and is more common in southern Europe, Africa and Asia.
Preventing these diseases
Avoidance – removal of long grasses and trimming of shrubs in the garden limits the likelihood of exposure. Try to keep your dog away from tick breeding grounds such as tall grass or brush especially during the warmer, months of the year. Remember, they will be most likely found in areas where there are more sheep and deer. Of course summer is the peak season for gundog working tests and these are exactly the sort of areas where we send our flat coats into for the most challenging retrieves!
Repellents and pesticides – in my experience these vary greatly in their efficacy – the most effective preparations are only available through your vet who will give you the best advice on what should be used for your circumstances. There are long lasting, waterproof spot on preparations and chemical-impregnated collars that can be used. More recently a long acting tablet medication has been launched which also works against fleas for three months. This is a very promising development.
Physical removal – I strongly recommend the use of a tick hook. These are cheap, simple to use and the most effective means of removing the entire body of the tick (including its mouthparts). Please remember not to touch the body of the tick yourself – always use a tissue. There are reports of people gaining exposure to disease through contact of their skin to the body of the tick.
When we visited Northumberland this summer we spent our evenings at the B&B going through our dogs with a fine tooth comb and tick-hook. It is surprising how many you find – despite using the chemical preventatives.
Other parasites
I have chosen to discuss ticks in this article; sadly there is not enough space for me to include detail on the other main disease risks (Leishmaniasis and Dirofilariasis) identified from travelling overseas. These diseases are transmitted by sand-flies and mosquitoes – it is very important to be aware of these if you visit the Mediterranean regions of Europe with your dog. Speak to your vet about if before you leave.