Tick control

Ticks are common parasites affecting dogs and cats in many areas of the world. They require a blood feed to complete their development and acquire this through biting their preferred animal host. They have well developed mouth parts that allow strong attachment to the skin for several days, as well as specialized saliva which allows them to feed on blood efficiently. The ticks seen on dogs and cats are usually adults. However, these adults have developed from immature tick stages that survive in the environment for several seasons/years. Types of environment suitable for tick development include forest, grass and moorland vegetation close to wild mammals or birds on which they can feed during their immature stages. Dogs and cats most commonly become infested with ticks when they are in walking, working or hunting in these areas. Some specialized ticks can develop in kennel environments. The risk of dogs and cats being bitten by ticks may vary with the time of year.

Ticks may cause several problems when they bite, eg:

• They can transmit a number of serious potentially fatal diseases via their saliva. These include babesiosis (piroplasmosis), ehrlichiosis, anaplasmosis, borreliosis, rickettsial infections, and several viral diseases. It depends on where pets are in the world as to the importance of each disease.
• Severe skin reactions may occur around the site of a tick bite in sensitive animals.
• In certain areas of the world (eg Australia), some of the ticks produce a toxin which causes paralysis. Tick paralysis is a serious disease and can be fatal.
• Very occasionally when there are a large numbers of ticks attached to a cat, especially if the cat is small or young, blood loss may be severe enough to cause anemia.

Many of the diseases mentioned above may be difficult and expensive to treat. Some are also transmissible to humans. Most ticks are only noticed by owners when they have been active for around a week, and are large enough to see clearly. For these reasons, if there is any risk, it is very important to use tick control and prevention.

Many different species of ticks can feed on dogs and cats. The main group is known as the Ixodidae, and they are responsible for transmitting the major diseases mentioned above. Not all ticks that feed on dogs and cats are infected with disease but the risk needs to be considered. For information on the species of ticks that could cause problems in dogs and cats in a specific region, contact your local veterinary, veterinary laboratory or veterinary school. It is difficult to determine the difference between tick species and expert identification is required. In the laboratory, ticks can be identified by looking at microscopic differences in their anatomy or by molecular testing of their DNA.

If identification is planned, it is very important to remove the tick without damage to its head parts as these are used for anatomical identification. Place the tick with some of the cat's hair in a clean container with a tightly fitting screw top and take to your veterinary practice. They will preserve the tick if further work is required.

Cats that live or roam in high risk areas (forest, grassland or moorland), especially if they are mostly outdoor cats, or if they are hunting, should be examined every day during peak tick periods of spring and fall. Be sure to check the head, ears and forequarters including the feet. If adult ticks are identified, they should be removed using a proper mechanical device available from your veterinarian.

Where tick paralysis is suspected, animals should be taken immediately to a veterinarian without attempting to remove any ticks. Ticks may increase the volume of the toxin they inject if they are touched or removed incorrectly and anti-venom may be given before tick removal.

Care must be taken when choosing a product for treating ticks on cats. Many of the products that are safe for dogs are toxic for cats, especially those containing the synthetic pyrethroid drugs. 

There are various products recommended specifically for cats. They can have different modes of application (sprays, oral chews, spot-on products and collars) and different lengths of action (28 days, 12 weeks or 6-8 months). Your veterinarian can discuss which is appropriate for your pet. 

Ticks that are well attached when treatment is started, may still be attached 24-48 hours later even though they are dead. They should be mechanically removed carefully (as mentioned above for live ticks) to prevent head parts being left within the skin.

The main population of ticks occurs in the outside environment in areas that are not appropriate for spraying chemicals. However, a few species of tick can survive well in the kennel or household environments including cars. The use of a household spray containing synthetic pyrethroids (usually permethrin) as recommended for flea control could be used in these circumstances. It is wise to contact your veterinarian in this situation.

Cats at risk are those visiting environments optimal for ticks. Strong tick populations are found in urban areas as well as rural, so most cats are at risk and may benefit from regular checks and treatment. Hunting or roaming in forests (especially along tracks with grass verges), moorland vegetation, and rough pasture land are all high risk and regular treatment is required. 

Ticks are more likely to be active in spring and fall but may be found through summer in humid areas. Warmer winters are also opening the possibility of year-round tick activity. Tick control should be continuous through this period and treatments applied according to the manufacturer's directions. In high-risk cats, or those with vulnerable owners, it is recommended to continue through winter as well.

If your pet is traveling into an area where tick-transmitted diseases are common, continuous regular treatments are needed. Ask your veterinarian for advice.

If applying anti-tick spot-on products or collars to your pet for the first time or if you are re-starting treatments after a break, it may take several days for the drugs to spread over the entire body in the skin oils and hair. If you are planning a trip where ticks are a problem, it is recommended to apply the treatment several days to a week in advance to ensure optimum protection.