Tick season is on its way- what you need to know to protect your dog

Deer tick

 

What are ticks and how do you know when to worry?

Ticks are what we call Ectoparasites- they survive outside of the animal. These pests are relatives of the spider (also hated, I’m told). The kinds of ticks you need to worry about will vary depending on your geographic location and general climate. Unfortunately they are something that cannot be entirely avoided regardless of your location.
Even pets that spend most of their time indoors are at risk.

The main reason these pests are cause for concern is due to their ability to transit viruses once they latch to your pet. There are many viruses that can be transmitted including Lyme Disease, of which people are the most familiar with.

How does my dog become infected?

Ticks are unable to “jump” per say, but transfer onto animals and humans when they come into contact with plants, brush, weeds, and long grass. They often go undetected due to their small size.

Image result for ticks

Take a look- before they cling to a host and become engorged from blood, ticks are actually very tiny. This is another reason they are so dangerous- by the time they are large enough to be detected, they may have had enough time to transmit any viruses they may be carrying.

Here you can see the difference in size between an unfed and an engorged tick.

Image result for ticks

When a tick finds a suitable host (ie: dog, cat, human, etc), it grasps the skin and cuts the surface. The tick then inserts its feeding tube into the host. May of them contain small barbs that help hold it into place. Some even secrete a cement like substance that aids the process. They also secrete a substance with anesthetic properties to allow them to feed without going noticed (sneaky little buggers)!

Infection may occur from the saliva of the tick itself, or may not occur until the tick begins bloodsucking. Pathogens may also be transmitted to tick from the host during this process. This process usually continues for a few days. Once the tick is engorged it drops off and awaits its next opportunity to infect the next host.

Almost all ticks go through 4 stages over the course of their life- egg, six-legged larva, eight-legged nymph, and adult. Ahh the circle of life!

Tick life cycle
Courtesy of the CDC

Which ticks are causes for concern and what diseases can they transmit?

Of the ticks that exist, only a handful bite humans and pets. The ticks that are of concern will vary from state to state.

Here are some of the most common:

American dog tick

American dog tick (Dermacentor variabilis)Approximate distribution of the American dog tick in the United States of America

Commonly found:  East of the Rocky Mountains; Pacific Coast

AKA: “Wood Ticks”

Highest risk period: Spring, summer and fall though bites reported anytime temperatures above freezing

Disease Transmitted: Tularemia; Rocky Mountain Spotted Fever

Backlegged tick
Blacklegged tick (Ixodes scapularis)

Approximate distribution of the Blacklegged tick in the United States of America

Commonly foundNortheast states; Midwest states

Highest risk period: Spring and summer

Disease Transmitted: Lyme Disease, Anaplasmosis, Babesiosis, Powassan Disease

Brown dog tick
Brown dog tick (Rhipicephalus sanguineus)

Map of the United States showing approximate distribution of the Brown dog tick. The entire United States is affected.

Commonly found: Worldwide

Disease TransmittedRocky Mountain Spotted Fever

Note: Dogs are the primary host, though the tick may also bite humans

Gulf coast tick

Image for Gulf Coast tick (Amblyomma maculatum)Image result for gulf coast tick cdc

Commonly found:  Atlantic, Gulf of Mexico

Highest risk period: Risk persists throughout the year

Disease Transmitted: Rickettsia parkeri rickettsiosis (a form of spotted fever)

Lone star tick

Lone star tick (Amblyomma americanum)

Map of the United States showing the approximate distribution of the Lone Star tick. The area affected is the eatern half of the country.

Commonly Found: Southeastern and Eastern United States

Disease Transmitted: Ehrlichia chaffeensis and Ehrlichia ewingii (Ehrlichiosis), Tularemia, Southern Tick Associated Rash Illness

Rocky mountain wood tick

Rocky Mountain wood tick (Dermacentor andersoni)

Map of the United States showing the approximate distribution of the Rocky mountain wood tick. The area effected is the Northwestern part of the country.

Commonly Found: Rocky Mountain states and Southwestern Canada

Disease Transmitted: Rocky Mountain Spotted Fever, Colorado Tick Fever, Tularemia

Western blacklegged tick

Western blacklegged tick (Ixodes pacificus)

Map of the United States showing the approximate distribution of the Western blacklegged tick. The area affected is the western coast.


Commonly Found
: Pacific Coast of the United States (especially northern California)

Disease Transmitted: Anaplasmosis, Lyme Disease


Disease Transmission

Rocky Mountain Spotted Fever

RMSF is caused by the bacteria Rickettsia rickettsii. The ticks most commonly associated with transmission are the American Dog Tick and the Brown Dog Tick. It is the most prevalent Tick Born Disease (TBD) in Arkansas though it is associated with many other regions in the United States.

Symptoms most commonly begin 2-14 days after a tick bite. It is a severe illness and can be fatal if left untreated. Symptoms are non-specific and are similar to other flu-like illnesses. Most complain of fever, headache, nausea, vomiting, and abdominal pain.

Rash is associated with RMSF, and often presents with the characteristic petechiae. This can help make the otherwise uncertain diagnosis, though the rash may not present until late in the illness after the patient becomes severely ill. Of course characteristic skin changes are more difficult to discern on a dog and may otherwise go unnoticed. This typically manifests as bruised/purplish spots on the skin. Dogs may also develop conjunctivitis (reddening of the eyes) as seen in humans.

Early cases can be treated with antibiotics. If intervened upon too late, both humans and dogs will progress to multiple system organ failure and die from the illness.

Rocky mountain spotted fever

The rash of Rocky Mountain Spotted Fever:

Image result for rash of rocky mountain spotted fever in dogs

Conjunctivitis in dogs associated with Rocky Mountain Spotted Fever:

Image result for conjunctivitis in dogs

Lyme Disease

Lyme Disease (LD) is caused by the bacterium Borrelia burgdorferi. Only 5-10% of dogs infected will become symptomatic, however due to the prevalence of the disease, Lyme Disease affects a significant number of dogs. Young dogs seem to be affected disproportionately.

LD also causes generalized, non-specific symptoms. The disease characteristically causes inflammation of the joints which can result in lameness. Lameness typically lasts a few days and then reoccurs weeks later- either in the same joints or in entirely different joints. Other associated symptoms include anorexia, weight loss, fever, depression, and rarely nervous system complications. Dogs do not develop the classic rash of erythema migrans (aka bulls eye rash) around site of the bite like humans do.

The disease is treated with antibiotics, though this does not always successfully eradicate the bacteria. In some canines symptoms will resolve and then return at a later date. The dog always remains at risk for later secondary complications including the development of kidney disease.

Read more about symptoms of LD in dogs here.

Check out this great site Pets and Parasites to look up the prevalence of Lyme Disease in your area (they break it down by state, city, and county).

Information on other tick born diseases

Tularemia:

Tularemia in Dogs– Pet MD

Tularemia in Dogs– VCA Hospitals

Overview of Tularemia– Merk Veterinary Manual

Erlichiosis:

Erlichiosis in Dogs– Pet MD

Erlichiosis control and potential vaccine – Pet MD

Powassan Disease:

Powassan Disease – CDC

Is Powassan Disease a threat to pets? – Pet MD

Anaplasmosis:

Anaplasmosis in Dogs – VCA Hospitals

Anaplasmosis in Dogs – Pet MD

Canine Anaplasmosis – Pet Health Network

Babesiosis: 

Parasite infection (Babesiosis) in Dogs – Pet MD

Pesky Summertime Pests – Pet MD

Colorado Tick Fever:

Colorado Tick Fever – NY Times

They want to suck your pets blood! – Downtown Animal Care Center

 

Stay tuned! Next week Woof will show you how to properly remove a tick and we will review vaccinations for various tick born diseases.

 

 

 

 

 

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