Scrub typhus and tick awareness for Tokyo dog owners: the trails, the ticks, and what vets want you to know

There is a particular pleasure to being a dog owner in the Tokyo basin that has nothing to do with the city itself: the ease with which you can escape it. The Chuo Line runs west into the mountains in under an hour. Takao-san — the most-visited mountain in the world, some estimates suggest — is 47 minutes from Shinjuku on the Keio Takao Line. Okutama, with its deep river valleys and genuine wilderness character, is reachable in about 90 minutes from Shinjuku via Ome. The Tanzawa mountains to the southwest draw serious hikers and their dogs every weekend. Tokyo dog owners are, as a community, enthusiastic trail-goers — and that is exactly why tick awareness matters here in a way it simply does not in the city itself.

The tick species present in the Kanto region's forested and semi-forested areas are capable of transmitting disease both to dogs and to the humans hiking with them. The risk is real and documented. It is also genuinely underappreciated — particularly among expat dog owners who may be more accustomed to reading about scrub typhus in the context of Southeast Asian travel, or who associate tick-borne disease in dogs primarily with the European Ixodes ricinus complex. The tick species in the Kanto mountains are different, the diseases they carry are different, and the prevention approach deserves specific attention.

The tick species found on Kanto trails

Two genera account for the majority of tick encounters on dogs hiking in the Kanto region forests: Haemaphysalis and Ixodes. Haemaphysalis flava and Haemaphysalis longicornis (the Asian longhorned tick, also called ヤマアラシダニ in Japanese contexts) are widespread across wooded areas of Honshu and are the ticks most commonly found on dogs after Kanto mountain walks. Ixodes ovatus and Ixodes nipponensis are also present in the region, particularly at higher elevations. These species have questing behaviour — they climb vegetation and wait for a passing host — which means a dog moving through tall grass, leaf litter, or undergrowth at trail edges is at meaningful exposure.

What diseases these ticks carry — and the crucial distinction about scrub typhus

It is important to be precise about scrub typhus here, because the terminology is frequently confused. Scrub typhus (つつが虫病, tsutsugamushi disease) is caused by Orientia tsutsugamushi and is transmitted to humans by the bite of infected trombiculid mites (chigger mites, ツツガムシ), primarily of the genus Leptotrombidium — NOT by ticks. These are a different type of arachnid altogether. While dogs can carry trombiculid mites on their fur and bodies after hiking through scrubby vegetation (and can therefore bring mites into human contact), dogs themselves do not appear to develop clinical scrub typhus in the same way humans do. The human risk from scrub typhus near Tokyo is a real and documented seasonal concern in certain rural areas of Japan, but it is a mite-borne disease, not a tick-borne one.

The tick-borne diseases that are clinically relevant for dogs in the Kanto region are different. Japanese spotted fever (日本紅斑熱, Nihon kōhan-netsu), caused by Rickettsia japonica, is transmitted primarily by Haemaphysalis flava and Ixodes species, and it affects both dogs and humans. Human cases have increased in Japan over recent decades and are reported across the Kanto, Tokai, and Chugoku regions. Dogs exposed to infected ticks can develop fever, lethargy, reduced appetite, and in some cases a characteristic rash or petechiae (small blood-spotted skin lesions). While dog fatalities from Japanese spotted fever are not commonly reported in the literature, the disease warrants veterinary attention. Canine Babesiosis, caused by Babesia gibsoni, is also transmitted by Haemaphysalis longicornis and is the tick-borne disease most extensively documented in dogs in Japan — particularly in Shikoku and Kyushu historically, but with cases reported across Honshu including the Kanto region.

The trail risk zones around Tokyo

• Takao-san (Mt Takao, 599m): by far the most accessible and heavily used trail for Tokyo dog owners. The heavily forested slopes and the less-used trails on the northern and southern flanks (trails 3, 4, 6) pass through tick habitat year-round, with peak activity in spring (April–June) and autumn (September–November). Dogs are permitted on most Takao trails except around the Yakuoin temple area and certain paved paths during peak tourist periods.
• Okutama valley (Mt Mitake, Mt Mito, Okutama gorge): denser, less managed forest; genuinely wild edges where deer, wild boar, and the small mammals that host tick larvae are abundant. Higher tick exposure than Takao-san, particularly in the valley undergrowth.
• Tanzawa mountains (Kanagawa prefecture, accessible via Odakyu Line to Hadano/Shibusawa): the Tanzawa range has an active deer and wild boar population and has been identified in Japanese veterinary literature in relation to tick exposure. Tick bite reports in this range are common among hikers.
• Oku-Chichibu (Saitama): longer day trips or overnight hikes; genuine wilderness with substantial wildlife activity. Highest tick exposure of the major trails accessible from Tokyo. Not for casual hikers but popular with experienced dog-trekking owners.
• Suburban green corridors: even closer to the city, the larger Tokyo parks — Sayama Hills (Tokorozawa), the Tama river corridor, the Showa Kinen Park woodland sections — have lower but non-zero tick activity. Post-walk checks are still worthwhile.

The tick season in the Kanto region

Unlike tropical climates with year-round tick activity, the Kanto region has a pronounced seasonal tick pattern. Haemaphysalis ticks have two principal activity peaks: spring (March–June) and autumn (September–November). These correspond to the periods of most comfortable hiking weather in Tokyo — which means the times when trail use by dog owners is heaviest overlap with the times of highest tick activity. The hot, wet core of summer (July–August) sees somewhat reduced tick questing activity as temperatures become extreme even for ticks, though activity does not cease entirely. Midwinter trail walks carry the lowest tick risk but are not zero.

Post-hike tick checks: what to do and where to look

The tick check after every trail walk is not optional — it is the single most effective thing you can do alongside preventive products. Ticks take time to attach firmly and transmit disease; finding and removing them promptly (within a few hours of attachment) dramatically reduces transmission risk for tick-borne pathogens. Check your dog systematically: run your fingers through the coat from the skin outward, paying particular attention to the areas ticks prefer — around the neck and ears, inside the ear canals, between the toes, around the groin and armpits, and around the base of the tail. On short-haired dogs this is fast; on Shiba Inu or longer-coated dogs, it requires patience.

If you find an attached tick, remove it with fine-tipped tweezers or a tick removal tool (ダニ取りピンセット, available at Japanese pharmacies and pet shops), grasping as close to the skin as possible and pulling upward with steady, even pressure. Do not twist, crush, or apply substances such as petroleum jelly or heat to the tick — these approaches can cause the tick to regurgitate and increase disease transmission risk. After removal, clean the site with antiseptic. Save the tick in a sealed bag in case your vet wants to see it. If you develop a rash or fever within two to three weeks, tell your physician that you were on mountain trails and found a tick.

Prevention products for trail-going dogs in Tokyo

Prescription tick prevention for dogs in Japan has improved significantly and most Tokyo veterinary clinics stock or can order the main systemic preventive options. Systemic oral preventives (the isoxazoline class — afoxolaner, fluralaner, sarolaner) provide reliable tick kill and are the current first-choice recommendation for dogs with regular trail exposure. They work by killing ticks that attach and begin to feed, generally before meaningful pathogen transmission has occurred. Products available in Japan include NexGard (afoxolaner, monthly oral), Bravecto (fluralaner, three-monthly oral or spot-on), and Simparica (sarolaner, monthly oral) — your veterinarian will advise on the appropriate choice for your dog given weight, health status, and any other prevention medications being used concurrently.

• Start tick prevention before the spring hiking season begins — late February or early March is appropriate for dogs with regular trail exposure.
• Year-round prevention is increasingly recommended for dogs that hike regularly in the Kanto mountains — the autumn peak follows closely after summer.
• Permethrin-based topical repellents are NOT safe for dogs in the same formulations used for humans, and should not be used on dogs. Consult your vet for safe topical options.
• Check yourself for ticks after every hike. Scrub typhus from chigger mites and Japanese spotted fever from ticks are both reportable human diseases in Japan. Your doctor should know you were on Kanto mountain trails if you develop fever or a rash.
• Confirm trail rules for dogs before you go — Takao-san has specific sections where dogs are restricted, and rules vary by trail designation.