What Is Tick-Borne Disease in Dogs?
Tick-borne diseases pose a significant threat to dogs and their owners, with tick infestations being a common concern among pet caregivers. Ticks, which are ectoparasites, reside on the exterior of their hosts and come in various species that prey on dogs throughout much of the United States at different times of the year.
For ticks to survive, they must latch onto their hosts and feed on their blood. Unfortunately, ticks can harbor bacteria, viruses, and parasites, which they can transmit to our pets through their bites, leading to a range of illnesses. These illnesses often present with symptoms such as fever, joint pain, lethargy, and abnormal blood work. Ticks thrive in woody and grassy areas but can also infest homes.
The majority of ticks found in the United States are classified as hard ticks. The Companion Animal Parasite Council monitors the distribution of ticks and the diseases they carry.
Here is a list of some common ticks and their typical geographical locations:
- Lone Star tick (Amblyomma americanum):
- Habitat: Prefers leaf litter and wooded areas with wildlife.
- Region: Commonly found in the Southeast and Eastern United States.
- Gulf Coast tick (Amblyomma maculatum):
- Habitat: Prefers tall, grassy meadows, open woods, and trails.
- Region: Commonly found along the Southern Atlantic coastline and the Gulf Coast.
- American dog tick (Dermacentor variabilis):
- Habitat: Prefers tall, grassy meadows and open woods.
- Region: Commonly found east of the Rocky Mountains, also in parts of California.
- Rocky Mountain wood tick (Dermacentor andersoni):
- Habitat: Prefers tall, grassy meadows, open woods, and trails.
- Region: Commonly found in the Rocky Mountain states and Southwest Canada in higher elevations.
- Eastern black-legged (deer) tick (Ixodes scapularis):
- Habitat: Prefers leaf litter and wooded areas with wildlife.
- Region: Commonly found in the Eastern United States.
- Western black-legged tick (Ixodes pacificus):
- Habitat: Prefers leaf litter and wooded areas with wildlife.
- Region: Commonly found in the Pacific coastal regions.
- Brown dog tick (Rhipicephalus sanguineus):
- Habitat: Can infest homes and kennels.
- Region: Found across North America, including Alaska and Canada.
Most Common Types of Tick-Borne Disease:
- Lyme Disease
- Causative agent: Borrelia burgdorferi, a spirochete bacterium
- Transmitted primarily by: Bites from Ixodes ticks
- Common signs: Lameness, fever, decreased appetite, lethargy, kidney failure
- Ehrlichiosis
- Causative agent: Ehrlichia ewingii and E. canis, intracellular bacteria
- Transmitted primarily by: Bites from Lone Star and brown dog ticks
- Common signs: Hemorrhage, fever, lethargy, decreased appetite, lameness
- Rocky Mountain Spotted Fever
- Causative agent: Rickettsia rickettsii, intracellular bacteria
- Transmitted primarily by: Bites from Dermacentor, Amblyomma, and Rhipicephalus ticks
- Common signs: Fever, lethargy, weight loss, bleeding abnormalities
- Babesiosis
- Causative agent: Babesia species, hemoprotozoan parasites
- Transmitted primarily by: Bites from Rhipicephalus, Ixodes, and Dermacentor ticks
- Common signs: Weakness, bleeding issues, fever
- Bartonella
- Causative agent: Bartonella species bacteria
- Transmitted primarily by: Some species of Bartonella transmitted by ticks and fleas
- Common signs: Fever, weight loss, decreased appetite, coughing, lameness, weakness
- Hepatozoonosis
- Causative agent: Hepatozoon americanum and H. canis protozoans
- Transmitted primarily by: Ingestion of brown dog ticks
- Common signs: Decreased appetite, fever, lethargy, dehydration
- Tularemia
- Causative agent: Francisella tularensis bacteria
- Transmitted primarily by: Bites from Dermacentor and Amblyomma ticks
- Common signs: Fever, decreased appetite, enlarged lymph nodes, eye abnormalities, abscesses
- Tick Paralysis
- Causative agent: Neurotoxin spread through tick saliva
- Transmitted primarily by: Bites from Dermacentor and Ixodes ticks
- Common signs: Rapidly progressive paralysis of legs starting in rear and progressing to all four limbs, difficulty breathing
- Anaplasmosis
- Causative agent: Anaplasma phagocytophilum, intracellular bacteria
- Transmitted primarily by: Bites from Ixodes ticks
- Common signs: Lethargy, lack of appetite, fever, dehydration
Symptoms
Symptoms of tick-borne diseases in dogs vary, and while some dogs may not show any symptoms, common signs include:
- Fever
- Loss of appetite
- Painful or swollen joints
- Lameness
- Swollen lymph nodes
- Bruising
- Abnormal bleeding
- Lethargy
If left untreated, tick-borne diseases can result in severe damage to various bodily systems including the kidneys, nervous system, immune system, vascular system, and heart. Many tick-borne illnesses also affect blood health, leading to significant bleeding issues and impaired blood clotting. Unfortunately, these conditions, along with other tick-related ailments, can prove fatal if not addressed promptly.
Causes
The causes of tick-borne diseases in dogs primarily stem from ticks themselves, although it’s crucial to understand that ticks are not typically the originators of these diseases. Instead, ticks become carriers of bacteria and protozoal organisms during their life cycle. Subsequently, when ticks bite dogs, they transmit or transfer these diseases to them. Tick paralysis stands as an exception, as it is caused by toxins present in the saliva of ticks.
Diagnosis
Veterinarians typically diagnose tick-borne diseases in dogs by considering the history, symptoms, and potential exposure to ticks.
Various diagnostic tests are available for tick-borne diseases, but veterinarians commonly begin with a multi-species test, such as the SNAP 4Dx test. This test is frequently used in clinics and requires only a small blood sample. Results are rapid, usually available within 10 minutes, enabling prompt initiation of necessary treatments. The SNAP 4Dx test screens for the three most prevalent tick-borne diseases: Lyme disease, anaplasmosis, and ehrlichiosis, as well as heartworm disease.
In addition to the SNAP 4Dx test, veterinarians often conduct blood chemistry analyses, complete blood counts, and urinalyses for dogs with confirmed or suspected tick-borne diseases. These additional tests help assess the severity of the disease and its impact on various organs and metabolic functions.
Treatment
The typical treatment for tick-borne diseases in dogs involves a course of antibiotics lasting between 10 to 28 days. Common antibiotics used include doxycycline, enrofloxacin, clindamycin, azithromycin, or imidocarb. The dosage and duration of treatment depend on the specific disease.
In addition to antibiotics, other medications and supportive therapies may be necessary based on the clinical signs exhibited by the dog. This can include pain relievers, anti-inflammatory drugs, intravenous fluids, and in severe cases, blood transfusions.
Dogs with immune-mediated conditions might require steroids and immunosuppressive drugs as part of their treatment regimen. For dogs experiencing kidney failure due to tick-borne diseases, intensive and aggressive treatment is often necessary initially. Lifelong dietary and lifestyle adjustments may also be required to manage the condition effectively.
Recovery and Management
Mild cases often respond well to a single course of antibiotics.
For severe cases, management varies according to symptoms, and these diseases may result in lifelong side effects and complications. Some dogs with tick-borne diseases may show no symptoms and are diagnosed through routine screening.
Overall, most cases of tick-borne disease have a positive prognosis. However, certain diseases like Lyme nephritis can lead to more uncertain outcomes.
Prevention
Preventing tick-borne diseases in dogs primarily involves avoiding contact with ticks and tick-prone areas whenever feasible. Maintaining year-round tick and flea preventive measures for your dog is essential. Prevention methods include oral medications, topical treatments, or collars containing pesticides, repellents, or growth inhibitors.
Environmental treatment is vital in high-tick areas, whether it’s your home, yard, or kennel. Pesticide treatments may be necessary to control tick populations. While it’s impossible to completely eliminate tick exposure for active outdoor dogs, using tick-repellent products can help. Additionally, thorough grooming after outdoor activities can help detect and remove ticks before they bite.
It’s crucial to recognize that some tick-borne diseases can affect both dogs and humans (zoonotic diseases). While humans typically contract these diseases through tick bites rather than directly from pets, dogs can carry ticks into the house that may later bite humans. Therefore, preventive measures for both pets and humans are important in tick-infested areas.
Tick-Borne Diseases in Dogs FAQs
How are tick-borne diseases in dogs tested?
Veterinarians utilize fast and simple blood tests to diagnose tick-borne diseases in dogs.
What are the potential long-term consequences of tick-borne diseases in dogs?
Certain tick-borne diseases may exhibit fluctuating clinical symptoms, necessitating multiple rounds of antibiotic treatment. While some dogs may not experience any enduring side effects, others might endure chronic conditions like kidney disease or arthritis stemming from tick-borne illnesses.