Ticks are blood-sucking external parasites of humans, pets, livestock and wild animals. They are also vectors of a wide variety of disease-causing organisms to animals including humans. There are around 850 described species worldwide, of which only a few exist in Ireland. Only one species is common in Ireland - Ixodes ricinus - there is a possibility that Dermacentor reticulatus may be present here, though this has not been confirmed. The latter species is present in the UK. Rhipicephalus sanguineus (brown dog tick) though present in southern Europe is not thought to occur in Ireland. Ticks are wingless and do not fly or jump.
Ticks are efficient hunters, waiting (“questing”) in brush or tall grass and when they sense vibration, carbon-dioxide (CO2), warmth and humidity, from a passing animal (or human), they climb aboard, attach and start to feed on its blood. Immature ticks are flat and only 0.5-3mm in size. They have special mouthparts which allow them to attach to their hosts. During the attachment process the tick uses its secretions mixed with host skin to form a cement which strongly attaches it to the host rendering it difficult to remove. Tick saliva contains an anaesthetic, so your pet will not feel the bite and neither will you!
And once attached, ticks on dogs/cats or other mammals remain—often unnoticed—for several days, making them excellent carriers for disease. Ticks are generally only noticed when they are filled with blood and protrude through the pet’s coat (or a human's skin). They resemble coffee beans and can vary in colour from grey to red or purple. But ticks aren’t just out in the wilderness—they can be transported much closer to home by rodents and birds. Tick larvae, nymphs or adult ticks can easily end up in residential areas, creating a whole new tick population waiting to be fed in your own garden or neighbourhood park.
Ticks are found in habitats that are populated by a supply of vertebrate hosts, mainly mammals and birds. Some of the most productive habitats are rough grasslands, moist woodlands and areas of vegetation around the edge of forests, along forest trails where a dense mat close to the ground provides a warm moist habitat to harbour developmental stages. There is a seasonal risk period for exposure from April to October, mainly influenced by sufficiently high temperature and humidity in the ticks’ environment to initiate activity and questing.
After feeding, an engorged female falls off to lay 3,000-6,000 eggs! It can take up to 3 years for the adult tick to develop. The eggs are laid in the environment and hatch to larvae which attach to another host, feed, fall off and moult to nymphs. These in turn attach, feed, fall off and moult to an adult completing the life cycle as in the diagram below.
When ticks bite, they can cause a range of signs including:
It is important to note that many dogs and cats harbouring ticks may not display any signs at all!
Ticks also spread disease, and as external parasites, are second only to mosquitoes in terms of their public health importance worldwide. When a tick feeds, its saliva mixes with the animal’s blood allowing for the transmission of any infectious agents (bacteria and viruses) that they are carrying.
Tick borne diseases in Ireland and the UK include mainly Lyme disease, but conditions, considered endemic on the continent, may be brought in via infected ticks from other European countries. Please check out our disease risks page to know more about the hazards associated with infestations of fleas or ticks.
Various products are available for controlling ticks. Your veterinary practitioner is best placed to advise you on the product of choice for your pet. For further information on the product for ticks (and fleas), marketed by MSD Animal Health, please click here.