What is the pea-sized brown thing fixed to my dog's leg?
Walking through fields and woods involves brushing against low vegetation. Sometimes unwanted guests will hitch a ride and become attached to you. They are ticks, blood-sucking parasites related to the mites. They not infrequently fix themselves to dogs and cats as well and can be seen in great profusion on hedgehogs (these poor animals support the greatest range of external parasites of any mammal, including fleas, ticks and mites of various species).
These small, pea-sized, brownish creatures may at first appear wrinkled but before too long they expand to resemble shiny little peas - full of blood. They are found on a wide range of both wild and domestic animals but they will on occasion attach themselves to people, especially if they have bare legs or lay down in the grass. Unfortunately, sheep ticks can transmit Lyme Disease, a potentially serious condition in humans caused by the bacteria Borrelia burgdorfi. Most ticks do not carry the bacteria but in some areas, particularly where there are high populations of wild deer, there is a chance of infection. Fortunately, it is unlikely that a tick will transmit the disease in the first few hours of feeding and, so long as it is properly removed as soon as discovered after being in the field (see below), the chances of catching it are very low. However, the site of tick bites should be checked occasionally after being bitten. The first symptom of the disease is a pink or red rash around the site of the bite that is not normally itchy, raised or painful. If medical attention is sought at this stage, the condition will clear up rapidly with suitable antibiotic treatment. More serious symptoms may develop if the disease is left untreated for longer periods, often because the patient has not realised a tick bit them.
Sheep ticks can also carry a disease of sheep called 'louping-ill' as well as diseases of cattle.
The only safe way to remove a tick is to grasp it as close to the skin as possible with a fine pair of forceps and pull firmly and steadily without jerking or twisting. Be careful not to crush the tick's body. If, as sometimes happens, the ticks mouthparts are left imbedded in the skin, do not worry as this does not increase the chance of transmission of Lyme Disease. In such cases, an ordinary antiseptic cream should be applied to the area of the bite to avoid infections due to common skin pathogens.
Never apply heat (e.g. lighted matches, cigarette ends) to attached ticks. Do not use chemicals such as alcohol, nail polish remover or petroleum jelly to ticks before removal as these substances can increase the risk of infection by stimulating the tick to regurgitate saliva into the wound. When first discovered the fine forceps/tweezers can be used to gently remove the tick. It is a good idea to always wash or shower after sitting or rolling around in sheep or deer areas such as downs and woods.