Ticks are more than just a nuisance—they can pose serious health risks to your dogs. Across the globe, there are nearly 900 different species of ticks, but about 25 of them are particularly dangerous to pets because they can transmit serious diseases. In fact, ticks are responsible for spreading at least 15 different diseases to dogs, including Lyme disease, anaplasmosis, and ehrlichiosis.
Unfortunately, tick exposure isn’t just a summer problem. It can happen year-round in the U.S. All it takes is one infected tick bite to transmit a dangerous disease to your dog. That’s why understanding tick-borne diseases, spotting their symptoms, and taking preventive steps are crucial for every dog owner.
Are Tick-Borne Diseases in Dogs Contagious?
This is a common question, and the answer is important to know:
Tick-borne diseases are not contagious between dogs and people or from dog to dog directly. The disease can only be transmitted through the bite of an infected tick. In other words, your dog cannot pass the illness to you, another dog, or another animal. However, if an infected tick bites your dog and later bites you (or someone else), the disease can be transmitted that way.
Most Common Tick-Borne Diseases in Dogs
Lyme Disease
Lyme disease is one of the most well-known tick-borne illnesses in dogs. In endemic areas, up to 50% of ticks can carry Lyme disease bacteria, putting many pets at serious risk. It’s especially common along the Pacific Coast, in the Northeast, and the upper Midwest.
Lyme disease is caused by the bacterium Borrelia burgdorferi, transmitted by black-legged ticks (also known as deer ticks). The tick must stay attached to your dog for 24 to 48 hours to transmit the infection. Symptoms include:
- Fever
- Lethargy
- Painful or swollen joints (leading to lameness)
- Loss of appetite
- Enlarged lymph nodes
If left untreated, Lyme disease can cause ongoing problems such as arthritis or even kidney failure. Diagnosing Lyme disease can be tricky, as many signs mimic other illnesses, and some dogs may test positive for life without showing symptoms. Always consult your veterinarian for the best treatment plan.
Anaplasmosis
Anaplasmosis is another serious disease caused by the bacteria Anaplasma phagocytophilum, transmitted by deer ticks and brown dog ticks. It is most common in the Northeast, upper Midwest, and along the West Coast.
Symptoms typically show up one to three weeks after a tick bite and include:
- Fever
- Poor appetite
- Lethargy
- Dehydration
- Vomiting or diarrhea
- Painful, swollen joints
- Rarely, bleeding from the nose, neck pain, or seizures
As with Lyme disease, some dogs infected with anaplasmosis may show no signs at all.
Ehrlichiosis
Ehrlichiosis is caused by bacteria transmitted by brown dog ticks and lone star ticks. It can be transmitted to your dog within just three to six hours of a tick bite.
Symptoms may appear one to three weeks after infection and can include:
- Fever
- Lethargy
- Painful, swollen joints
- Loss of appetite
- Weight loss
- Pale gums
- Bleeding from the nose or eyes
- Blood in urine or stool
- Bruising on the gums or belly
- Eye inflammation (uveitis)
Early detection and treatment are vital, and most dogs respond well to antibiotics like doxycycline.
How Do You Spot and Prevent Tick-Borne Diseases in Dogs?
You can’t 100% guarantee your dog will avoid ticks, especially in areas where they are abundant, but you can greatly reduce the risk with some simple steps:
- Avoid Tick-Infested Areas: Ticks thrive in shady, humid, and grassy environments. Keep your dog away from woods, tall grass, leaf piles, and overgrown shrubs.
- Yard Management: Keep grass trimmed short and remove leaf litter and fallen branches. Create a 3-foot wide barrier of gravel or wood chips between the yard and wooded areas.
- Use Tick Prevention Products: Year-round use of tick preventatives like topical treatments, pills, or tick collars is highly recommended. Products like Simparica Trio, Frontline, Advantix, and others can help protect your dog.
- Vaccinate: There is a vaccine available for Lyme disease, but not for anaplasmosis or ehrlichiosis.
- Perform Regular Tick Checks: After walks or outdoor play, inspect your dog thoroughly. Focus on hidden areas like between the toes, under the collar, around the ears, and under the tail. Removing ticks promptly can greatly reduce disease transmission risk.
- Bathing: Giving your dog a bath with tick-repellent shampoo can help remove any ticks that haven’t yet attached.
- Blood Tests: Some dogs may carry tick-borne diseases without showing symptoms. Annual blood tests can catch hidden infections early.
- Watch for Symptoms: Limping, lethargy, loss of appetite, fever, or bruising can be early signs of infection. If you notice anything unusual, visit your veterinarian immediately.
How Common Are Tick-Borne Diseases in Dogs?
Tick-borne diseases are increasingly common. In certain parts of the U.S., up to 13.3% of dogs are affected by Lyme disease alone. Due to warmer climates and expanding tick habitats, experts expect tick-borne illnesses in pets to continue rising.
If you live in or frequently visit areas with high tick populations, you need to be especially vigilant year-round—not just in summer months. Remember, it only takes one infected tick to cause a serious health issue for your dog.
Final Thoughts
Ticks may be tiny, but they pose a major threat to your dog’s health. The best defense is a combination of prevention, vigilance, and veterinary care. Make sure your dog is on a veterinarian-recommended tick preventative, check them often, and consult your vet if you notice any suspicious symptoms. Early detection and prompt treatment can save your dog from long-term complications—and could save their life.