Published on October 4th, 2016 | by Debbie Martin0
Tick Borne Disease and What You Should Know
Ticks are a small arachnoid parasites which live on the skin of a host animal and feed on its blood throughout their life cycle. In doing so, they can provide a vector for a number of harmful diseases. What’s worse, they can transmit from one host animal to another, providing that disease with a means of spreading.
In this article, we’ll examine the various sorts of ticks there are, and the various tick borne diseases they carry. We’ll also suggest ways in which you might limit the threat each disease poses to your pet.
Ixodes are the most common genus of tick in the UK. They live for three years, during which time they’ll go through three stages – larvae, nymph and adult. They feed once per year, allowing them to then mature to the next life stage. The larval stage uses small birds and rodents as hosts, while nypmhs and adults are able to live on larger mammals.
Ixodes rincinus is the most likely culprit when a dog or cat becomes infested with ticks. They can carry a bacteria known as Borrelia burgdorferi. This microbe is particularly troublesome, as it causes one of the more infamous tick-borne diseases: Lyme disease.
Lyme disease is among the most common tick-borne diseases in the world, but it’s asymptomatic in more than 90% of cases. Both cats and dogs can get infested with ticks, however Lyme Disease in cats is thought to be extremely rare. In dogs the disease presents as inflammation, which eventually leads to lameness. Affected dogs may also lose their appetite and become depressed – and there may even be complications affecting the heart or nervous system.
Transmission of Lyme’s Disease is triggered when a tick begins to feed. The responsible bacteria Borrelia burgdorferi starts to multiply in the tick’s gut, before eventually spreading to the salivary glands, where it’s able to be transmitted. This presents us with a window of between twenty-four and forty-eight hours, in which we might prevent transmission by removing ticks with a tick-hook. Consequently, nymphs pose a greater threat than adult ticks – as they’re smaller, and more likely to escape detection during this crucial period.
These ticks can also pose a risk to humans as Lyme’s disease is a zoonotic disease which can also be transmitted to people. Recent cases of Lyme’s disease in humans has seen a huge increase in England, however this is in most part due a greater awareness of the problem among pet owners.
Lyme disease is borne across the country by small animals – particularly by rodents and birds, who are able to carry Ixodes rincinus at its larval stage. Deer are also important hosts, especially in Wales, where they’ve helped to spread the disease through the Wye valley.
Dermacentor ticks are a less common variety of tick that has arrived in the UK relatively recently. They’re notable in that they cause the only tick-borne disease not caused by an infectious organism: tick paralysis, which is caused by a neurotoxin injected by the tick. They’re also capable of transmitting a number of harmful bacteria – most notably Babesia canis, which can cause a form of fatal anaemia in affected animals.
Babesiosis is a disease that’s been introduced to the UK relatively recently. We don’t currently know how long it takes to transmit – but it’s thought to be more than forty eight hours, following which will come a period of incubation that lasts for between one and three weeks. The protozoa will seek out red blood cells, attacking and destroying them. This will bring about a number of unpleasant symptoms, as the host animal’s circulatory system becomes progressively less able to get oxygen to the organs that need it. The dog’s immune system will attempt to combat the problem by dispatching antibodies to destroy infected cells. The problem is that these antibodies aren’t very selective about which cells they destroy – and many healthy cells will also be lost, exacerbating the problem and causing severe anaemia.
Dogs suffering from Babesiosis will pass blood through their urine, and their gums will become paler as a result of impaired bloodflow. They’ll also become generally weaker as their cells begin to suffer from a lack of oxygen.
This species of tick has yet to find its way to the UK, as the climate here is unsuitable for it. That may change in the future, however, as the tick is thought to be migrating northward through Europe. Consequently, the chance of it establishing a foothold in the southeast is cause for concern.
Rhipicephalus Sanguineus is especially troubling because its life-cycle is far shorter than that of an Ixodes tick – they can infest a house and lay eggs very regularly in a similar manner to a tick. This makes eradicating them much more troublesome.
As well as the potential for infesting a house, this variety of tick might also act as a vector for a number of diseases. These range from Mediterranean spotted fever, which can infect people as well as dogs, and cause rashes, headaches, and photophobia, to heptazoonosis, which can cause dogs to become anaemic and lethargic.
Tick-control while travelling
When you take your dog abroad, you’ll need to take steps to prevent them from being bitten – and check for ticks on a daily basis, removing any you find with a tick hook. Removing them by hand might result in the front of the parasite being crushed – which, if it’s feeding, can cause harmful fragments to become lodged in the bloodstream, causing a secondary infection.
It used to be the case that treating dogs returning to the UK with tick treatments was mandatory – but since 2012 this has ceased to be so. Many have taken this to suggest that the threat is lessened – but many vets disagree, citing the increase in R sanguineus incidences in the southeast of England. To be safe, it’s best to use an appropriate treatment recommended by your vet for a few weeks before travel, to ensure that you pet is adequately protected.
Tick-control at home
As well as treating your dog with tick treatments, it’s also important to take environmental measures seriously. Dogs which are allowed to walk through long grass, rummage through undergrowth in pursuit of interesting sights and smells, will be more vulnerable to tick infestation. Be sure that their sleeping arrangements are kept clean, and that you check them for ticks after taking them for countryside walks. With the right care and select medication, we can ensure that the risk ticks pose to our pets is minimised.