Gemma Gaitskell
Dr Gemma Gaitskell (BVetMed MSc MRCVS, Royal Veterinary College, London)
 
Tick Prevention

Ticks are a common type of parasite which feed on blood and are found around the world. They are more prevalent in humid environments with plenty of long grass, forests, moorlands and other types of environment where there is a mixture of small and medium sized mammals and birds for them to feed on. There are many different types of ticks, which can bite dogs and this varies depending on the area and environment.

Types of Ticks and Their Life Cycle

Ticks are a type of insect which must feed on blood from animals to complete their lifecycle. They are an important factor in the transmission of various diseases. Ticks can be divided into two groups:

  • Hard Ticks – All tick species in the UK belong to this group where part of their body is covered by a hard substance. Examples of hard tick species found in the UK include Dermacentor, Haemaphysalis, Ixodes, Rhipicephalus. Other hard tick species are also found in warmer climates and these include Amblyomma, Boophilus, Ixodes, Rhipicephalus.
  • Soft Ticks – These are of greater importance in warmer climates. Soft ticks lack the hard covering on their body and have a more leathery appearance. Some soft tick species include Argas, Ornithodoros, Otobius.

Hard ticks feed less often but on larger amounts of blood, whereas small ticks feed more often on smaller amounts of blood. There is also a difference between the number of different types of animal which hard and soft ticks must feed on to complete their lifecycle and move from one stage to the next. Some species of hard ticks may feed on the same animal at each of their life stages or on two or three different types of animal. Soft ticks must nearly always feed on different types of animal between their life stages.

Tick Life Cycle

Tick Life Cycle

Tick Life Cycle

Ticks need to feed on blood from an animal – their host – in order to survive, however, they spend a relatively short amount of time on the animal and the rest of their life is spent in the environment.

Once hatched from the egg there are three stages in the tick life cycle. As ticks feed they usually become larger in size. To progress between life stages the tick must feed on blood at least once. Whether this blood is from the same dog or type of animal depends on the species and how their life cycle has developed.

The Stages of a Tick's Life Cycle:

  • Eggs (laid by adult female) → LarvaNymphAdult

Diseases Transmitted by Ticks

Tick on Dog's Foot

Ticks on Dog's Paw

Ticks play an important role in the transmission and spread of many diseases. These diseases are often serious and can be complicated and pricey to treat. Ticks can carry diseases and transmit them through their eggs from one generation to the next or whilst they feed. The mechanism of how a disease spreads depends on the disease, which is being transmitted.

Ticks can transmit diseases, such as Lyme Disease and Tick-Borne Encephalitis to humans, so control of ticks on dogs, especially pet dogs is important. There are also numerous other diseases transmitted by ticks but here are some of the most common ones spread to dogs in the UK and Europe:

Lyme Disease

Lyme Disease, otherwise known as Borreliosis, is the most common disease transmitted by ticks in the UK. Lyme disease is caused by a bacteria called Borrelia burgdorferi and, in dogs, the most common symptoms are joint stiffness and pain, lameness, a reduced appetite, fever and swollen glands. These symptoms are not very specific so it is important to know if a dog has been in contact with ticks in order to help with diagnosis. Antibiotics and anti-inflammatory drugs can be used to effectively treat the disease.

Tick-Borne Encephalitis and Louping Ill

Tick-Borne Encephalitis (TBE) and Louping Ill are diseases that are closely related. It is relatively rare for dogs to develop clinical signs of TBE, but in people, it is more common. There are different strains of the virus, some more severe than others. The disease is found across most of Europe. In dogs that do develop clinical signs these include: fever, as well as neurological signs, such as a loss of coordination, trembling, convulsions and paralysis, which can lead to death. There are no specific treatments available to kill the virus so treatment revolves around treating the symptoms. This lack of a specific treatment means that tick control is particularly important.

Babesiosis

Babesiosis is caused by a microscopic parasite called Babesia, which is carried in ticks saliva. It is more common in warmer climates and southern Europe but in recent years with climate change and a greater movement of pets has been seen in northern Europe. Once a dog is infected, it can also transmit the disease through its bite and blood. It is thought that the parasite takes a little while after the tick has bitten a dog to be transmitted, which emphasises the importance of quick removal of ticks.

The Babesia parasite hides in the dog’s red blood cells, preventing the immune system from attacking it and causing the red blood cells to explode. Common symptoms include anaemia, lethargy, fever, reduced appetite, jaundice, dark brown urine, fast breathing and swollen glands. The disease can be treated with medications that are effective, but can have side effects, however, if left untreated, it can be fatal. Although the this type of Babesia parasite can spread between dogs it is not thought to be a great risk to people. Dogs infected with Babesia are also commonly infected with Ehrlichia.

Bartonellosis

This disease is caused by a bacteria called Bartonella. It can be spread from animals to humans, although it is not usually fatal in people. In dogs, common symptoms include, lameness and arthritis, fever, swollen glands, general inflammation and irritation, vomiting, diarrhoea and seizures. The disease can be treated with antibiotics.

Ehrlichiosis

Ehrlichiosis is caused by a parasite transmitted through a ticks saliva. As with Babesiosis it is a disease more common in warmer climates but is now being found in northern Europe. It is also known by several other names including Lahore canine fever, canine rickettsiosis, canine haemorrhagic fever and Nairobi bleeding disease. The parasite hides inside the dogs red blood cells, which provide protection from the immune system and eventually destroys them, spreading the disease further.

Symptoms are often unspecific but can include lethargy, fever, reduced appetite, excessive bleeding from small cuts and an increased susceptibility to infections. Some dogs may be able to recover from the disease without treatment, but will still often carry the disease, which can re-emerge if it becomes stressed. Ehrlichiosis can be treated with specific antibiotics over a long period of time in conjunction with other treatments to combat the side effects of the disease, such as blood transfusions to help anaemia. If treated early dogs can make a full recovery.

Immediate Problems Caused by Ticks

In addition to transmitting diseases tick bites themselves can cause swelling, irritation and eventually wounds. Wounds can then become infected and this can result in secondary problems. If a dog is bitten by a large number of ticks at once this can also lead to anaemia and in some cases paralysis.

Detecting and Removing Ticks

Tick Remover

Tick Remover

During the Spring, Summer and Autumn months it is important to check your dog regularly for ticks, especially if it is walked in countryside areas with long grass and other livestock. The time of year when ticks are most prevalent in the environment depends on the climate and geographical region.

When a tick is first picked up by a dog they are usually very small in size and often go unnoticed. As they feed on a dog’s blood they get larger and swell up. The extent of this depends on what type of tick and at what point in its lifecycle it is. If a tick is left it will usually drop off when it has finished feeding after approximately a week. If you find one or two ticks on your dog and feel confident removing them, then the best thing to do is remove them as soon as possible. However, if a dog is covered with a large number of ticks it is best to seek veterinary advice.

There are many methods people use to remove ticks, but ultimately, the best way is to gently twist it off in an anticlockwise direction, using tweezers or a special ‘tick remover’ which are safe and effective, whilst being sure to also remove its mouthparts. This is important as if they are left in the skin they can cause an inflammatory reaction and become infected.

Spot-on tick treatments also act fairly rapidly and kill ticks, which then drop off when dead if a dog has not been treated prior to acquiring the tick. Safe and effective spot-on tick treatments can be purchased from your veterinarian, who will also be happy to demonstrate how to safely remove a tick if you are unsure or worried that you may have removed one and left the mouthparts in place.

How to Prevent Dogs Getting Ticks

Tick Prevention

Tick Prevention

Prevention and control of ticks is advisable, as they can transmit disease and their bites can cause skin irritation. There are several different chemicals that can be used to protect dogs from ticks. How effective these products are can depend on the type of tick and also whether the product is applied according to guidelines.

Often swimming and contact with water can make products less effective and reduce the duration over which they act. Some products act as tick repellents, as well as killing the tick, although they do not always have an effect before the tick attaches itself. This means that there is still the possibility of infection with any disease that the tick may be carrying. For maximum protection it is essential to follow the guidelines that advise how frequently the product should be applied to the dog.

Tick Control with Spot-On Treatments and Collars

Spot-on treatments are an easy and effective way of helping to control ticks on dogs. A small amount of liquid containing chemicals that kill ticks is applied to the skin on the back of the dogs neck, just above the shoulder blades. These products can be purchased from vets and are safe for use on dogs. They are usually effective for around a month and must then be reapplied. Swimming and contact with water can reduce their efficacy and the time over which they are effective.

Collars containing chemicals effective against ticks can also be used and those sold through vets are effective. There are many other brands available for purchase from pet shops and supermarkets that are not as well regulated and tested for safety or as effective. Collars are usually effective over a longer period of time than spot-on treatments but this may vary depending on the brand. They often use the same chemicals to repel and kill ticks.

If dogs are in an environment where they are at a high risk of being bitten by ticks a combination of spot on treatments and collars can be used to maximise protection.

Chemicals to Kill Ticks

Spot-on treatments and collars use chemicals effective at repelling and killing ticks. Although products are sold under many different brand names the chemicals they contain are often the same or similar. These chemicals include:

  • Permethrin
  • Fipronil
  • Pyripole
  • Amitraz

Products containing these chemicals may also be effective against various other parasites, such as fleas, meaning only one treatment is needed, but care should be taken if different combinations of products are used, ensuring that they are compatible.

Permethrin can be toxic to cats so care should be taken using any products which contain it if cats are present in the household. There are some dog breeds which can be sensitive to certain chemicals contained in tick treatments, so it is important to consult your veterinarian if you are unsure about which products are safe for your dog.

Tick Control with Oral Treatments

In recent years, some products in the form of tablets for tick control have become available for use on dogs. These are easy to administer to the dog as they are usually palatable and their efficacy is not affected if the dog is in contact with water, making them useful for dogs that swim a lot. These treatments can be prescribed by your vet.

Tick Control in the Environment

Although ticks do not tend to be a problem in the home in the same way as fleas, it is advisable to check areas where dogs sleep and any furniture they are allowed to lie on for ticks. Sprays used to control fleas, containing permethrin can be useful to treat areas of the house or car where dogs which have been exposed to ticks have been. However, if there is a heavy infestation of ticks, professional pest control may be needed. Care should be taken using any sprays containing permethrin if there are cats in the household, as this chemical can be toxic to cats.

The Importance of Tick Prevention

Regular use of effective and safe tick control products is strongly advisable throughout the months and climates where ticks are active, particularly in countryside environments where dogs are at a high risk of infection. Apart from the immediate irritation and discomfort that ticks can cause to dogs their control is important because they can potentially transmit diseases, which affect both dogs and humans.

The bottom line when it comes to effective tick control is that the careful use of effective products at regular intervals appropriate for the dogs lifestyle is important to try and prevent dogs picking up ticks and contracting any diseases they may carry in the first place.

Dog Breeds