Name American Dog Tick
Latin Name Dermacentor variabilis
American Dog Ticks are one of Ontario’s three most common tick species, alongside the Deer Tick and the Brown Dog Tick.
How do you get rid of American Dog Ticks?
American Dog Ticks are unlikely to infest your home as they prefer to live outdoors. However, thorough checks of clothing, the nape of the neck and scalp, armpits and, groin and knees, pets and objects should be undertaken when returning from risk areas.
How to identify American Dog Ticks
American Dog Tick eggs are minuscule and tend to be tan to red-brown. Larvae are usually less than 1 mm. Nymphs are poppy seed sized, usually 1-2 mm long with eight legs, similar-looking although smaller than adult males. Female American Dog ticks are identified by their distinctive larger whitish scutum which is set against their darker brown coloured body. Males are smaller and have a brown-coloured body with all-over streaks of white. An unfed female tick is typically 5 mm in length and can expand to 15 mm when engorged with blood meal.
As is typical of ticks, the female American Dog Tick dies shortly after laying eggs (up to 5000). After hatching, the larvae have six legs and will immediately begin searching for host bodies, typically rodents and birds, for their first blood meal. It is during this first feeding that diseases are usually contracted. After their first moulting, American Dog Ticks in the nymphal stage will have eight legs and will be drawn to larger hosts (deer, humans, dogs and cats) and be capable of spreading disease. They can survive for up to 2 years at any given stage without feeding on a host, although in ideal conditions the American Dog Tick can fully develop within a 3-month period.
Signs of an American Dog Tick Infestation
American Dog Ticks are unlikely to infest your home as they prefer to live outdoors but are more commonly accidental invaders. Those who frequent tick-infested areas should familiarize themselves with not only tick bites but also symptoms of the diseases that they transmit.
Where did they come from / how did I get them?
Hardier than the Deer Tick, the American Dog Tick can survive in tall grasses across Canada between Saskatchewan and the Atlantic Coast, predominantly found in areas with little or no tree cover, especially along walkways and trails. Active in temperatures above 4 degrees Celsius American Dog Ticks are unable to fly or jump, but will instead ‘quest’ for hosts. In response to carbon dioxide or heat and vibration stimuli, ticks will climb a blade of grass or move to the edges of leaves, stretch their front legs forward, and mount an unsuspecting host as it brushes past. Once mounted onto its host, a tick will move around the body and select a preferred feeding site typically a warm and moist area around the neck, head, armpits, groin and knees.
What do American Dog Ticks eat?
As is typical of ticks, the American Dog Tick feeds on a variety hosts from mice to humans.
How Serious are American Dog Ticks?
American Dog Ticks are a known vector of Rocky Mountain Spotted Fever, Tularemia and are known to cause Tick Paralysis.
Rocky Mountain Spotted Fever: Restricted to the Rocky Mountain range of the United States and southwestern Canada, ticks may become infected with the R. rickettsii bacteria in the larval or nymphal stages. Male ticks can transfer Rocky Mountain Spotted Fever to female ticks while mating and once infected the tick carries the pathogen for life. Rocky Mountain Spotted Fever is commonly misdiagnosed as the flu. Typical symptoms include a fever and rash.The tell-tale red spotted rash on one’s palms or soles of the feet might not appear until after six days of other symptoms. Severe cases of Rocky Mountain Spotted Fever can involve the urinary, gastrointestinal, central nervous and respiratory systems and cause death. Only knowing that a tick bite occurred recently would lead a physician to diagnose Rocky Mountain Spotted Fever, so it’s important to monitor your body for ticks and tick bites.
Tularemia: Tularemia is caused by the disease pathogen Francisella tularensis that can be transmitted to humans and pets not only through tick bites but by contact with other infected animal bodies, ingestion of contaminated water and agricultural dusts and even through bioterrorism. Ticks bites typically catalyze glandular and ulceroglandular forms of Tularemia in combination with a dangerously high fever. Glandular Tularemia causes lymph glands to swell, typically around the armpits and groin, and Ulceroglandular Tularemia combines lymph gland swelling in addition to the formation of an ulcer at the site where the bacteria entered the body. If properly diagnosed and treated most patients fully recover within a period of several weeks through the use of antibiotics.
Tick Paralysis: Tick Paralysis occurs when a potent toxin from an adult female tick’s saliva is injected into the blood of the host (common in dogs) as it feeds on a blood meal. Tick Paralysis directly affects the nervous system of the animal and the onset of symptoms usually takes 6-9 days. Symptoms include vomiting, unsteadiness, high blood pressure, increased heart rate, loss of muscle control (apparent relaxation), excessive drooling, asphyxia, loss of appetite and pupil dilation. Symptoms of Tick Paralysis will usually subside upon the removal of parasites from the body of the animal, but it is imperative to have your pet treated by your veterinarian because even in cases where proper diagnosis and treatment is received, Tick Paralysis may be fatal. Although it is uncommon in humans, Tick Paralysis can affect people with a smaller body mass, most frequently, children. Tick Paralysis symptoms in humans are similar to those in affected animals and exist in increasing seriousness the longer the tick feeds on its host; symptoms may include respiratory failure, acute muscle weakness and even death. Like most tick-borne illnesses, diagnosis can be difficult without the knowledge of a tick bite, if ticks are found on a host they must be carefully removed and saved for testing.
Thankfully, American Dog Ticks must typically feed on the host body for upwards of 24 hours to successfully transmit the diseases they carry. If you find a tick on a person or pet:
Grasp the tick behind the head using tweezers and slowly remove it from the host (fingers can be carefully used if an appropriate tool is not on hand, wash hands thoroughly before and after tick removal). Do not crush the tick; crushing may lead to the release of dangerous fluids. Ensure that the mouthparts of the tick are fully removed and thoroughly wash the infected area. Seek medical attention. Save the tick body for testing and diagnosis.
How Addison can help Prevent American Dog Tick Infestations in the Future
When entering a suspected tick populated, or leaf-littered area:
Wear light clothing, long sleeves and long pants tucked into socks. Repellents: Deet-based skin repellent helps repel them, and Permethrin clothing treatment can kill ticks. Contact your veterinarian about available preventative treatments for ticks and other ectoparasites.
Ticks and other ectoparasites can enter the home on just about anything, on clothing, pets, people, and plants. In general, when returning from any densely vegetated, wooded or infested area where tick harbourages and activity are suspected, it is crucial to perform thorough checks of all incoming living and non-living objects. Ticks are drawn to moist and warm areas on their host bodies; be sure to check the scalp, nape, behind the ears, armpits, groin, navel and knees. Always check twice. Immediately wash and dry all clothing on high heat and be sure to shower as soon as possible. Bathe and groom your pets and regularly check for ticks and other parasites.
Certain preventative measures can be taken as part of a system of physical controls:
Keep your home clean, check under furniture and the areas that pets frequent. Repair crevices and gaps around the structure, paying particular attention to possible entry points from outdoors. Keep your grass cut and maintain an organic free barrier of at least 1m around the exterior walls of the structure using gravel or woodchips. Dispose of all animal nesting material, and evict other pest populations in and around your property as ticks parasitize most rodent and avian pest species. Keep your lawn free of debris and leaf litter, keep children’s playsets clear of wooded areas.