All About Dogs by LowchensAustralia.com

If you are new to the tropics and own a dog, you will very shortly need to know about brown dog ticks.

Rhipicephalus sanguineus are different from the paralysis tick (Ixodes holocyclus), well known in Queensland or the cattle tick (Boophilus microplus). Brown dog ticks are not as life threatening but can develop into an irritating skin condition when in large numbers.

The brown dog tick is a parasite of dogs in tropical and sub-tropical countries including Australia.

If you find ticks on your dog in the NT, they are most likely to be brown dog ticks. Cattle ticks will also attach to dogs, if your dog runs in areas with cattle. You will find ticks attached anywhere on a dog but mostly where the dog cannot bite itself. Ticks attach mainly along the back, on the neck, in the ears and between the toes. Heavy infestations do occur in the Top End, especially in the wet season. Generally, these ticks will not attach to people.


EFFECTS

The tick embeds its mouthparts into the skin and feeds on blood and lymph, until it is engorged.

The blood loss can cause anaemia, and dogs can become listless. Tick numbers will increase rapidly if dogs are left untreated, and very high infestations may lead to death of the dog. The brown dog tick transmits the blood parasite, Babesia canis which causes a tick fever. Dogs raised in the Top End are generally not affected by this parasite due to their early exposure. However, introduced dogs or puppies are susceptible.


SURVIVAL

Ticks are excellent survivors. They lay large numbers of eggs and each stage can survive several months without feeding. They are most susceptible to strong sunlight, desiccation and very heavy rain. There are four stages in the life cycle of the tick: egg, larva, nymph and adult. The adult female tick leaves the dog after it is fully engorged and seeks out a dark sheltered position to lay its eggs- all 4000 of them. This may be in leaf litter, soil or under your best lounge chair. The eggs hatch into reddish brown larvae which are very small and difficult to see. They may be found crawling up walls. They attach to the dog and feed until engorged. Then they drop off the dog and moult to become nymphs. Nymphs are larger than larvae and can be distinguished by having eight legs instead of six. Nymphs also feed on blood until they are engorged and then drop off the host. They then develop into female or male adults. The female attaches and starts to feed.

The engorged female is the largest and most obvious stage in the cycle. Engorged females are about 12 mm in length and are brown to blue/grey in colour with dark brown legs. Male ticks are much smaller, shiny dark brown in colour and actively move about. They do not engorge like the females, but may be found close to females. All adult ticks have eight legs.

The brown dog tick is most active during the early wet season.


BREAKING THE CYCLE

Ticks are out of control if you can see them crawling up your walls. If tick numbers are allowed to increase, control becomes a costly and prolonged exercise. Treat dogs when tick numbers are low and keep infestations low. This is especially important at the start of the wet season as numbers will rapidly build to plague proportions. The old saying “ a stitch in time” is very true. To break the tick cycle you need to control ticks both on and off the dog. This is achieved by a combination of chemical and non-chemical means.


CHEMICAL CONTROL

Fortunately, there are a number of highly effective chemical products on the market. In fact there are so many products on the market that at times it may be a little overwhelming. Products basically vary in how they are applied and their active ingredient. Several different trade name products may all contain the same active ingredient, so read the fine print on the label.

Commercial preparations include sprays, washes, powders, collars, pour ons and oral treatments. Most active ingredients fall into the various chemical groupings of pyrethroids, organophosphates, carbamates, formamidines, insect growth regulators or inhibitors and adulticides. These products act on different sites within the tick.

Pour on
Pour on applications are easy to apply and are long acting. One of the most effective products is the topically applied fipronil, Frontline. It spreads over the skin and is deposited in sebaceous material. It is effective for up to one month against ticks.

Sprays and washes
Dogs treated with dips and washes must be thoroughly wet to the skin, with particular attention being given to inside the ears and between the toes. Generally these products are only effective for a limited time. Because the brown dog tick is a three host tick, regular chemical treatments at seven to 14 day intervals are required to break its life cycle. Washes generally contain organophosphates, synthetic pyrethroids or formamidines. Take care in applying these and follow safety instructions.

Of the cattle tick dips only Barricade ‘S’ is registered for use on dogs for the control of cattle ticks. One of its active ingredients is chlorfenvinphos. Do not use at intervals of less than three weeks.

Collars
These are another effective method of applying chemical for prolonged periods. However, exposure to water will affect the duration of protection. Collars generally contain organophosphates, synthetic pyrethroids or formamidines.

With all chemical treatments, it is very important to read and follow the manufacturers’ recommendations. Remember that some of these chemicals also affect human health. There are a limited number of treatments registered for use on animals under three months.

In the Top End weather conditions are favourable for tick survival for most of the year, except for short periods in the driest times and the wettest times. As long as dogs are monitored for tick burden, year round treatment would not be warranted. Commence control as soon as ticks are seen on the dog.

Treat all dogs at the same time.


OTHER CONTROL MEASURES

Constant reinfestation will occur if the dog’s environment is contaminated with tick larvae and nymphs. Treat the dog’s resting areas with an acaricidal spray. These are often organophosphate chemicals such as maldison or diazinon. Bedding, crevices in the kennel and any other items in the vicinity will harbour ticks so all of these must also be treated or removed.

If ticks have invaded your house, a commercial pest control operator should be consulted. Ticks will shelter in cracks and crevices associated with brickwork, skirting boards and mouldings and the use of powders/dusts with a residual effect is recommended. Products should be used only according to directions.

Dogs should be regularly checked for ticks. Pull off any ticks and destroy them. Ticks in the ear removed using blunt-ended tweezers.


Recommended actions for severe problem of ticks on dogs

1. Contact a commercial pest control operator to spray your house and yard. Alternatively, spray dog resting areas, kennel and bedding with Quick Kill Rinse Concentrate for Fleas, Ticks and Lice, Exelpet Fleaban Yard and Kennel Concentrate or Malaban Wash Concentrate weekly for three weeks until numbers are greatly reduced. (Remove dogs first). Dispose of bedding if possible. Elevate kennel above the soil.
   
   Note: These are organophosphates and are toxic to humans, so follow instructions carefully. They are poisonous if absorbed through the skin, inhaled or swallowed. Avoid inhaling. Wear gloves. Wash hands with soap and water after use or immediately if spills occur.
   
   

2. Treat dog with Frontline Top Spot Dog. Apply between shoulder blades onto skin (or use spray).
   
   Repeat treatment monthly until ticks are few in number.
   
   Alternatively, a tick collar could be used or a wash for ticks.
   
   

3. Restrict dog movements to treated area so no ticks are picked up elsewhere.
   

4. Treat all dogs at same time.
   

5. Do not allow "ticky" dogs into your yard.
   

6. Persist with treatment for at least four months.

An AgNote from the Northern Territory Government
Please visit their website at www.primaryindustry.nt.gov.au