Warm weather sets clock ticking on tick seasonPublished 12:00am Sunday, April 15, 2012
The sun is shining and it is unseasonably warm.
Of course, not many of us are going to complain during the spring or winter about global warming.
But everything seems to be sooner this year and it is going to cause problems.
I pulled my first tick off of me a couple of weeks ago. Then, this morning, a large engorged female dropped off a dog and was squished all over the treatment floor.
More ticks surviving the winter mean that there will be more tick borne diseases. Ticks and their habits are disgusting.
There are many different types of ticks in our area. All of which have benefitted from the mild winter and early spring.
A tick can take three years or more to grow up and mate. In the fall, the engorged females drop off their host (deer/cattle/dogs) and their hundreds of eggs are laid.
Lyme disease is a crippling arthritic disease that is carried by ticks. The organism is Borrelia burgdorferi which is a spirochete bacteria.
The deer tick is the vector (transmitting tick) and is a tiny black tick that is often missed on exam. It started in New England, but has spread west and south. This is something both pets and animals can get, but dogs can be vaccinated.
In the first spring, the tick hatches into a six legged larvae. It then searches for a small host, such as a mouse or chipmunk or such. It sticks it’s straw like mouth into the host and gets a blood meal.
Unfortunately, there is some back wash and stuff from the tick get into the host. But after it is full, it drops off to process the food. That summer and fall, the larvae that have fed will molt into nymphs (still with six legs).
They will overwinter as nymphs and any organisms in their blood will feed on the blood meal and grow with the tick.
Ehrlichia canis is a rickettsial bacteria that causes severe disease. Other species of Ehrlichia are not as dangerous or common.
E. Canis is carried by the brown dog tick (extremely common tick) and it infects the monocytes of the dog. , but the one that most commonly affects dogs and causes the most severe clinical signs is Ehrlichia canis.
This species infects monocytes in the peripheral blood. In the beginning, there is a fever and decreased white blood cell counts due to bone marrow suppression. The second phase can have the dog infected and shedding the bacteria without any signs.
But sometimes a chronic phase will cause a very low white blood cell count, bleeding, secondary bacterial infections, lameness, neurological damage, kidney and eye damage. This stage can be fatal.
The next spring, the nymph tick or seed tick, will search for another host. This may be a somewhat larger host such as a rabbit, raccoon or dog. After a blood meal (and any hitchhiking diseases), the tick will drop off and molt into an adult tick with eight legs.
The bacteria and blood parasites overwinter inside the now larger tick.
Another tick borne bacterial disease is caused by two different Anaplasma species. In the beginning the dogs can be very sick.
It can mimic lyme disease in the fever and arthritis. Fortunately there are tests to diagnose these. Sometimes, dogs will be diagnosed on a routine annual blood test that only have or had mild, flu-like symptoms.
Arthritis is commonly present, but vomiting, diarrhea, and/or respiratory signs or even central nervous system (meningitis) signs can be present. Anaplasmosis can affect humans also.
The next spring, adults attach and feed from their third host. Any bacteria that were growing in the tick from the first two hosts or even sometimes the mom tick, can be transmitted to the larger host of a deer, cow, dog or human.
Granted, it can take 24 hours for the feeding mechanism and disease transmission to happen, but knowing that any adult tick has fully fed on at least two other creatures is unnerving at best.
Engorged adult females are mated by the males attached around her and she will lay her eggs after she drops off her host.
For the record: applying alcohol, petroleum jelly, fingernail remover or a lit match is NOT a good idea. It may even cause the tick to regurgitate into your blood faster than it would have otherwise.
These “spouse” tales are not a good idea. Grab it by the mouth parts and pull straight out. Remember, that mouth could have been in two or three other creatures. Putting it in alcohol after it is removed means that it will die and can be tested if need be for infectious diseases.
By the way, snakes are out early also. We have seen our first (probable) copperhead bite of the year, but that is for next week’s article.