Introduction
Ticks are common external parasites to dogs, cats, livestock and wild animals. They are the most important arthropod vector of infectious diseases of veterinary importance. Apart from them benefiting the moist, dark ecosystems in which they live by serving as a food source for many reptiles, birds and amphibians, plus controlling wild animal populations, they spread tick-transmitted diseases that are often serious and difficult and expensive to treat (Nicholson, et al., 2019).
Optimal tick control is essential in protecting dogs and cats. The pathogens ticks transmit affect pets, livestock, humans and wildlife in many different ways. The main reasons for tick control are to protect hosts from irritation, the formation of lesions that can be secondarily be infected, toxicosis, paralysis, and of immense importance, the transmission of a variety of disease-causing organisms. Control also prevents the spread of tick species and the diseases they transmit to unaffected areas, regions, or continents (Otranto, et al., 2008).
Ticks are not susceptible to many insecticides commonly used to control fleas or lice. Ideally, dogs are protected from ticks through proactive, routine use of acaricides (i.e., tick control products) with residual activity before exposure to areas harbouring ticks otherwise severe infestations can occur. Functional anatomy and biological characteristics make controlling tick infestations challenging (Brogdon, et al., 1998).
Ticks in the environment
All tick species have a life cycle that involves egg, larva, nymph, and adult stages that lasts between 3 weeks and up to 3 years. The brown dog tick (Rhipicephalus sanguinous) has a strong host preference for domestic dogs and is usually found in and around homes and kennels where dogs live. Of the 4 most common species, only dog ticks are capable of infesting buildings (homes, barns, kennels) and can reach massive numbers in very close quarters with dogs, cats, and humans. Ticks remain attached to their hosts for several days before dropping off into the environment. Though it is often thought that ticks are a seasonal threat, the reality is that they can be present all year round.
The ideal environments for tick growth and development differ with the species involved but then again, ticks habitat commonly includes outdoor areas with woods (mixed forest), tall grass, shrubs, weeds, rough pasture, and moorland vegetation with appropriate populations of small mammals or birds on which they can feed during their immature stages. They are particularly found in humid environments. Dogs commonly become infested with ticks once they walk, work or hunt in these areas. Nevertheless, Rhipicephalus sanguinous (Dog tick) readily acclimatises to the kennel and household environments.
Tick Control in the Environment
Divergent to what most people think, the smaller rodents (e.g. mice, chipmunks and squirrels) are the hosts and carriers for most ticks. This, combined with an unkempt lawn, increases the presence of ticks near houses, kennels and barns and help them to easily attack humans, dogs, cats, and livestock. A great number of ticks in the environment search for a host by ascending brush, grasses, walls, or fences, pausing for movement or exhaling carbon dioxide as a signal to move to their desired host (Spickett, 1994).
Advances in climate study together with an improved understanding of tick–pathogen interactions, the spreading of ticks and the diagnosis of tick-borne pathogens raise questions about the impact of environmental factors on tick abundance and spread and the prevalence and transmission of tick-borne pathogens. Climate change correspondingly plays a role in the alterations in distribution and seasonal abundance of ticks and always difficult to disentangle factors impacting the abundance of tick hosts from those exerted by human habits. (Estrada-Peña, et al., 2012).
The following can be done to reduce the tick population in the environment: -
Clear tall grasses, brush around homes, leaf litter and maintain grass at a shorter height at the edge of lawns. This makes it difficult for ticks to find areas to quest and gain access to the dog
Place a 3-ft wide barrier of wood chips or gravel between lawns and wooded areas and around patios and play equipment. This will restrict tick migration into recreational areas.
When environment modification is not possible, it may be appropriate to restrict the dog’s access from areas harbouring ticks. Restricting a dog’s access from crawl spaces and gaps underneath kennels can help prevent the reacquisition of the dog tick while limiting the time spent in wooded areas may prevent infestations with ticks.
Mow the lawn frequently and keep leaves raked.
Stack wood neatly and in a dry area to discourage rodents that ticks feed on.
Keep playground equipment, decks, and patios away from yard edges and trees and place them in a sunny location.
Remove any old furniture, mattresses, or trash from the lawn that may give ticks a place to hide.
In cases of heavy environmental infestation with ticks, the use of acaricides to the environment can be done on-premises. A licensed pest control applicator should be consulted for advice. Areas under structures should be treated as well as vertical surfaces such as walls and fences.
In general, keep your yard and environment clean and less inviting to ticks waiting for a meal on you and your pet.
Tick Control on the Dog and Cat
The prevalence of ticks and tick-transmitted diseases can be decreased by the regular application of effective acaricides in dog and cat populations. There are several safe, effective, residual acaricides that kill ticks within 24-48 hours. These products include sprays, collars or spot-on products containing synthetic pyrethroids (e.g. cyphenothrin, deltamethrin, flumethrin, or permethrin.), fipronil, pyriprole, amitraz and oral isoxazolines such as fluralaner and afoxolaner. Most of these products have excellent activity for up to 28 days, and others have excellent activity for up to 90 days (fluralaner). Organophosphate products are effective but they are discouraged or banned due to human health concerns.
Products for Dogs:-
Tickicides never achieve 100% efficacy (90% is the threshold) due to variation in tick species or variability in the application. Therefore, tickicides should never be assumed to have removed the tick problem completely. Animals should still be checked for ticks regularly. Residual activity may be decreased by swimming and bathing and incorrect application. 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.
The products involved include washes, sprays, spot-ons and chewable tablets with varying duration of efficacy ranging from 7 days to up to 3 months depending on the product used.
References
Brogdon, W. G., & McAllister, J. C. (1998). Insecticide resistance and vector control. Emerging infectious diseases,, 4(4), 605.
Estrada-Peña, A., Ayllón, N., & De La Fuente, J. (2012). Impact of climate trends on tick-borne pathogen transmission. Frontiers in physiology, 3, 64.
Hendricks, A., & Perrins, N. (2007). Recent Advance in tick control. In Practice, 29, 284-287. doi:10.1136/inpract.29.5.284
Nicholson, W. L., Sonenshine, D. E., Noden, B. H., & Brown, R. N. (2019). Ticks (Ixodida),. In D. E. William L. Nicholson, & L. A. Gary R. Mullen (Ed.), Medical and Veterinary Entomology (Third Edition) (pp. 603-672). Academic Press. doi:10.1016/B978-0-12-814043-7.00027-3
Otranto, D., & Wall, R. (2008). New strategies for the control of arthropod vectors of disease in dogs and cats. Medical and Veterinary Entomology, 22(4), 291-302.
Spickett, A. M. (1994). Tick ecology. International journal for parasitology, 24(6), 845-849.