TAXONOMY AND BIOLOGY
Acarology is the study of ticks and mites. Fortunately, there are a number of excellent scientists who have devoted their lives to studying these creatures. Mites and ticks are related to insects; they fall into the same Phylum (highest category that similar animals or plants find themselves in), but have major points of distinction. The following is the taxonomic order (one might relate it to "a family tree") for classifying ticks:

Phylum: Arthropoda (insects, ticks, mites, spiders, Horseshoe crabs, millipedes, etc.)
Class: Insecta (insects)
Class: Arachnida (ticks, mites, scorpions, spiders, etc.)
Order: Araneae (spiders)
Order: Acarina (mites and ticks)
Family: Argasidae (Soft Ticks)
Species: Mammal Soft Tick
Family: lxodidae (Hard Ticks)
Species: Brown Dog Tick
Species: American Dog Tick
Species: American Wood Tick

SPECIES: LONE STAR TICK
There are over 800 tick species; about 15% of them are known disease transmitters. All ticks have 8 legs as adults; their bodies are divided into two segments (insects have 6 legs and 3 body segments). Except for the males of a few species, all ticks require blood for their survival.
A tick's life is divided into 4 stages: egg, larval, nymph and adult. The egg hatches into the 6- legged larva called a "seed tick". After feeding, the larva molts into the 8-legged nymph that is undifferentiated sexually. Finally the nymph molts into the 8-legged adult that can be differentiated into males and females. The adult female will start producing eggs after it has had a blood meal.

SOFT TICKS
Soft Ticks are covered with a "leathery" integument. If you were to look down on one from above, its head would not be visible. They are what this author categorizes as "nester". Rarely are they found far from a nest or other resting places of the species they are parasitizing. They can be important vectors of diseases of man or animals; however, in the United States their role as disease transmitters has been limited.

Soft Ticks establish themselves in a dog's resting area. They tend to cling to their host while feeding, dropping off when satiated, laying their eggs, and then returning to the host. Different than most Hard Ticks, some do not feed as larvae, while others only feed in larval stages. These can be very hearty; it has been demonstrated that they can survive as long as 3 years without a blood meal. At
times they can serve in the dual role as vector and reservoir for a specific disease (African Swine Fever is a good example).

HARD TICKS
Hard Ticks feed during each stage of their lives except when in the egg. When looking down on the discernible. Adult males can be differentiated from the female by the shape and size of a hard scutum found on their dorsal surface. They are rarely host specific. Most are found outdoors where they feed on smaller mammals such as rodents when in the larval and nymph stages, usually showing up on dogs and man when they reach adulthood. These ticks will attach themselves and stay on the host for considerable time. When they finally drop off they usually lay their eggs and the females will die.

A few species of ticks live their whole life on one host, and are appropriately called "one-host ticks." Most will feed on multiple hosts. A fully engorged tick can grow to 50 times its size before feeding.

SOME HARD TICKS AND THEIR BIOLOGY
We will discuss two of the many Hard Ticks. They serve to illustrate differences in development and though both serve as vectors of disease organ isms there are some specific distinguishing characteristics.

BROWN DOG TICK: This tick most commonly is found in the dog's habitat. You find it in homes and in kennels. It can transmit disease organisms to dogs, but is not known as a transmitter of disease to humans.

The females often lay as many as 3,000 eggs after engorging themselves with blood. They will lay these eggs in cracks in the floor or walls, in furniture, on the roof of kennels, rugs, etc. Eggs hatch in 20 to 60 days, dependent on temperature and moisture. Once hatched, the 6- legged seed tick will get on a dog if possible and feed for a few days, dropping to the floor when full. After dropping off the host the seed tick will hide from 1 to 3 weeks before molting into the 8-legged nymph. The nymph seeks a blood meal and will seek a dog to feed on. If reaching its fill, it will drop off and in a couple of weeks to a month will molt into the adult. Once again it is time for a blood meal, satiation and producing eggs.

Larvae, nymphs and adults can live for a considerable amount of time without a blood meal. Under the right conditions it is not uncommon to survive over half a year without a meal.

AMERICAN DOG TICK: This is an "outdoor" tick. While dogs are perhaps its favorite meal, these ticks will feed on many other warm blooded mammals if they are served up first. Rarely do these present as infestations in homes or kennels. The larval ticks tend to feed on small rodents and don't really seek dogs until the nymph and adult stages.

Interestingly, the females, which can lay as many as 6,000 eggs, end their life cycle at this point by dying. It usually takes 1 to 2 months for these to hatch into seed ticks. When they find a small rodent to feed on they usually do this for less than a week. They then develop into nymphs, which once again seek out rodents. If successful, they will spend a few days on the rodent, drop off and molt into adults. However, nymphs can go as long as a year and a half without a meal.

The adults will seek dogs, but will accept almost any mammal that comes along, including a person. Of concern, especially when considering control measures, adults can live for two years without a meal. Adult males tend to stay on their host animal, mating with females at any chance they get. Females drop off their host when ready to lay their eggs.

A FEW DISEASES ASSOCIATED WITH TICKS
TICK PARALYSIS: Though not caused by an infectious agent, it is a reaction to the salivary secretions of ticks. It is a disease seen in dogs and humans, though children seem to be the prime subjects. Both Soft and Hard Ticks have been incriminated as agents in this disease. In the United States, Hard Ticks, particularly ones that usually are found in wooded areas, appear to be the worst culprits.

The offending tick can usually be found on the head or neck region, being attached for 5 to 6 days before symptoms occur. As we will discuss later this is an outstanding reason to check pets and folks who spend time in "tick country", since removal will prevent the syndrome. Removal of the ticks in humans and dogs showing signs of tick paralysis is almost always curative. Usually, individuals will return to "normal" 6 to 8 hours after tick removal.

ROCKY MOUNTAIN SPOTTED FEVER (RMSF):
The American Dog Tick can serve as a vector of this ricketsial disease. There is still some conjecture as to whether or not dogs actually develop clinical RMSF, but infected ticks may maintain their ability to infect while feeding on dogs. If the tick transfers from a dog to man the infection can be transmitted. In dogs, one should be sure that what might be misconstrued as RMSF is not really Canine ehrlichiosis. Removal of the tick from a dog deserves a certain amount of caution.

LYME DISEASE: Though the American and Brown Dog Ticks are not considered major vectors of Lyme Disease they certainly can be transmitters of the organism responsible for the disease. The disease is caused by a spirochete and recent evidence has shown that a number of blood sucking insects can carry the organism. Again if you remove a tick, it would be prudent to inform your physician. However, all evidence to date seems to indicate that the tick must be attached at least 48 hours for transmission to take place. One more reason for tick inspection.

BABESLOSIS: This is a blood disease of dogs transmitted by ticks. Dogs exhibit weakness, loss of appetite, often respiratory signs and other digestive tract problems. Again, the tick must feed on the dog 2 to 3 days for transmission to take place.

EHRLICHIOSIS: This is a fairly new disease, at least in its recognition, and in dogs is caused by the ricketsial organism Ehrlichia canis. It is a disease of the immune system and white blood cells. Differential diagnosis is very difficult, as it can be confused with RMSF and other diseases. In early stages, the dog exhibits fever and depression. Eventually weight loss, increased urination and thirst become evident. If allowed to proceed the disease will eventually become chronic and not reversible. If treated early, there is a good response to antibiotics. Again the tick must feed over 24 hours to transmit the organism. There is increasing evidence that the disease as seen in humans is not caused by E. canis, rather by E. chaffeensis, a closely related species.

PREVENTION BEATS TREATMENT
Unfortunately, the worst tick season is generally in Spring and Summer, when we are most apt to be outdoors. Country folks are always at risk, suburbanites are seeing ticks as a bigger problem and urbanites with gardens are seeing an increased chance for exposure.
During the season, check your dog daily for ticks. Remember: Disease transmission via ticks takes time.
If your dog has access to fenced yards, cut the grass and be sure to trim along the edges and fences; ticks like high grass!
Avoid tick habitats if possible, i. e., stay on paths in woods so you don't brush against high grasses!
Check adults and children for ticks whenever you have been exposed to tick habitat!
There are a number of once a month treatments for dogs that give acceptable results in controlling ticks; work with your veterinarian on a preventative program!
Don't rely on tick repellents, most are not very effective in dogs (or people)!
Examine for ticks. Examine for ticks, and take one more look!

REMOVING TICKS
1. Promptly remove any ticks found. Do not use your bare hands, use gloves, tissues, etc.
2. Whenever possible use tweezers and a magnifying glass. Grab the tick firmly as close to the head as possible and pull slowly and steadily.
3. Save the tick in ajar, label it with the date and where you took it off (the dog or you).
4. Do not use Vaseline or similar drugs on the tick, it can stimulate disease organism release.
5. Treat the bite site with alcohol or a topical antibiotic, and remember to check the site over the next few days for infection.
6. Alcohol or a hot needle will sometimes assist in getting the tick to turn loose.
7. Remember to wash your hands when finished. Though many of the organisms ticks carry can be devastating to the host, we are fortunate that in most cases we have a window of opportunity for inspection and removal. Tick season means examining your dog for ticks.

This feature was prepared by Dr. Silberman at the request of Mary G. Finley of Encinal, Tex., who for warded a copy to The AMERICAN FIELD. Mrs. Finley has enjoyed a successful career with German Shorthaired Pointers and with pointers, notably Brush Country Spectre, National Champion, two-time Purina Award Winner, elected to the Field Trial Hall of Fame in 2001.