How To Protect Your Dog From A Disease That’s Just Around The Corner


As you know, March is National Tick Awareness month. Over the next few weeks, we are going to take the time to look at different ticks and how they affect your dog’s health. Today, let’s look at the deer tick, which is one of the ticks that carry Lyme disease. 

If you haven’t already, I recommend reading part one of this series.

The Deer Tick

Also known as the black-legged tick, the deer tick is one of the more commonly known species of ticks. That is because they are one of the species that spread Lyme disease, a very serious disease for humans and dogs.

Like many tick species, the deer tick is a three-host tick. This means that the host they feed on changes with each life stage.

Larvae Stage

Unlike many tick species, the deer tick is a bimodal tick. What this means is that there are two periods when the larvae are active:

  • May: These are eggs that overwintered and hatched in the spring.
  • August: Eggs laid in the spring hatch in August. This is when you see the heaviest concentration of larvae.

The deer tick larvae are a six-legged insect that is very hard to see. They are about the size of a poppy seed. In addition, they are almost lacking color, being nearly translucent.

Deer tick larvae will attach to small mammals, usually mice, squirrels, and chipmunks, and will feed for three to five days before they drop from their host.


Once the deer tick larvae forms, it will molt and become the nymph. They are active through most of the summer to a large degree and then, to a lesser degree, in early fall.

The deer tick nymph is actually linked to the most transmission of disease to humans and a high occurrence of transmission for dogs. They are eight-legged and slightly bigger than larvae, being about the size of a sesame seed. They are translucent, gray, and flat.

Deer tick nymphs will attach to a small mammal, birds, and dogs to feed. They are very attracted to humans at this stage. The nymphs will feed on blood for three to four days until they are fully engorged and then drop off.


The final stage of development for the deer tick is the adult stage. After the nymph molts, the adult deer tick emerges in the fall.

The adult deer tick is a dark brown to black colored tick. They are 3mm in length and have no white markings on their scutum. The female deer tick does have an orange to red color on the lower half of her body, below the scutum.

While male ticks will feed sporadically, it is the female tick that will engorge for five to seven days. Males will mate with several females while she is feeding. Once she has fed, she will drop from the host and lay up to 3000 eggs.

Although some adult deer ticks will engorge and lay in the fall, others will overwinter and will breed in the spring. Adult deer ticks feed off any animal, however, they are often found on white-tailed deer.

It is important to note that the deer tick has a lifecycle of 2 years on average; however, they have been known to live up to four years.

Habitat and Distribution of the Deer Tick


At one time, the deer tick was in a fairly small geographical area, they have now spread across a wide part of the United States including Southern and coastal New England, out toward Minnesota, up into Ontario, and down to the Mid-Atlantic States.

The tick can be found in many suburban communities. They prefer wooded areas where there is plenty of leaf litter for the larvae and nymphs.

Diseases Transmitted by the Deer Tick

Deer ticks present a number of health risks for both people and their pets. They are one of the leading causes of Lyme disease and several other diseases that are dangerous for people.


A serious bacterial disease the deer tick transmits to dogs and humans is Anaplasmosis. In dogs, it affects the dogs by infecting the platelets in the blood.

It affects dogs that have been bitten by the tick, especially if the tick becomes engorged. About one to two weeks after being bitten, symptoms will begin to occur, including:

  • Poor blood clotting
  • Lameness
  • Lethargy
  • Fever
  • Joint pain
  • Vomiting
  • Severe diarrhea
  • Lack of appetite
  • Seizures
  • Coughing
  • Nosebleeds
  • Red splotches on the gums

Treatment of Anaplasmosis is through an antibiotic regime for thirty days. If caught, the prognosis is excellent for the dog.


A parasite disease that dogs can contract several different ways including being bitten by the deer tick and several other species of ticks. Caused by the protozoal parasite transmitted by the bite. It takes about two weeks for incubation before symptoms are seen. However, some dogs can carry the parasite for several years before it is detected.

Symptoms that occur include:

  • Loss of energy
  • Pale gums
  • Weight loss
  • Fever
  • Dark colored urine
  • Loss of appetite
  • Jaundiced skin
  • Swollen abdomen
  • Discolored stools

Treatment can range depending on the severity and may include antibiotics, IV fluids, and/or a blood transfusion. Continued screening for several months is necessary. Highly communicable, all other dogs in the home will go through screening for the disease. 

Tick-Borne Encephalitis

Although there was some debate on whether dogs could become infected with tick-borne encephalitis, it has been a known problem for over 30 years.

Transmitted by the deer tick bite, there is a very high mortality rate. The disease incubates for one to two weeks before any symptoms begin to occur. Owners will see:

  • Acute fever
  • Ataxia
  • Sudden Aggression
  • Motor failure of the limbs
  • Vestibular syndrome
  • Encephalitis
  • Seizures

Treatment is an aggressive administration of non-steroid anti-inflammatories for up to a year. However, many dogs that contract the disease die even with treatment. Preventative measures included tick medications and the TBE vaccine. While designed for humans, the success rate with dogs is very high and a recommended prevention in high endemic areas.  

Lyme Disease

When it comes to ticks, Lyme disease is the one most people think of. It is a serious infection that leads to complicated disease in dogs. The disease occurs after a tick bite. Caused by bacteria from the spirochete species. 

It usually only occurs after the tick has attached for over two days. Unusually, it appears to affect young dogs more frequently than older dogs. In addition, Labrador Retrievers, Golden Retrievers, Bernese Mountain Dogs, and Shetland Sheepdogs and their mixes tend to be affected by kidney disease from the Lyme disease more than any other breeds.

Symptoms of Lyme disease include:

  • Reoccurring lameness lasting three to four days
  • Joint inflammation leading to swollen and warm
  • Kidney disease leading to kidney failure
  • Weight loss
  • Lack of appetite
  • Vomiting
  • Diarrhea
  • Heart abnormalities
  • Fever
  • Depression
  • Difficulty breathing
  • Stiff, arched back walk
  • Sensitivity to touch

Treatment is through a four-week antibiotic treatment. Dogs that develop Lyme may have a reoccurrence of the symptoms even after treatment. In addition, kidney disease can occur later in life.

While ticks are very serious, there are several treatments you can purchase for your dog. These treatments will prevent ticks from biting your dog and will give you peace of mind. With the spread of tick-borne diseases across North America, National Tick Awareness Month has never been so important.