Ticks are more than just annoying parasites — they can transmit serious diseases to both dogs and cats. As ticks continue to spread across North America, pet owners should not only know how to protect their pets but also how to recognize the signs of tick-borne illness.
Ticks are arachnids, not insects, and they feed on the blood of animals and people. Because they attach firmly and feed slowly, they can easily spread disease before they are noticed.
Lyme Disease
Lyme disease is caused by the bacterium Borrelia burgdorferi, transmitted primarily by the deer tick (black-legged tick) and the western black-legged tick.
Signs owners may notice in dogs:
- Sudden limping or shifting leg lameness
- Swollen or painful joints
- Fever
- Loss of appetite
- Lethargy
- Generalized pain
- “Walking on eggshells” appearance due to joint discomfort
In severe cases, Lyme disease can affect the kidneys and may cause:
- Vomiting
- Weight loss
- Severe lethargy
Signs owners may notice in cats:
- Fever
- Fatigue
- Decreased appetite
- Lameness
Anaplasmosis
Anaplasmosis is caused by a bacterium called Anaplasma phagocytophilum, which is spread by deer ticks and western black-legged ticks.
Signs owners should watch for in dogs:
Dogs:
- Fever
- Joint pain
- Lameness
- Lethargy
- Loss of appetite
- Vomiting or diarrhea
- Coughing
- Labored breathing
- Rarely, seizures
- Some dogs develop bruising or nosebleeds because the infection can lower platelet counts
Signs owners should watch for in cats:
- Fever
- Lethargy
- Anorexia
Ehrlichiosis
Ehrlichiosis is spread by the brown dog tick and can progress through acute, subclinical, and chronic stages.
Early signs in dogs may include:
- Fever
- Swollen lymph nodes
- Weight loss
- Respiratory distress
- Bleeding disorders
- Neurologic signs such as unsteadiness
Chronic ehrlichiosis in dogs may cause:
- Anemia
- Nosebleeds or bruising
- Eye problems
- Lameness
- Swollen limbs
- Severe weakness
Signs in cats include:
- Fever
- Lethargy
- Loss of appetite
- Anemia
- Low platelet counts
- Bleeding tendencies
- Enlarged lymph nodes or spleen
- Weight loss
- Eye inflammation
Rocky Mountain Spotted Fever (RMSF)
Rocky Mountain Spotted Fever, caused by Rickettsia rickettsii, is transmitted by the American dog tick, the Rocky Mountain wood tick, and the brown dog tick.
Symptoms in dogs may include:
- Fever
- Muscle or joint pain
- Poor appetite
- Vomiting or diarrhea
- Swelling of the face or legs
- Depression
- Coughing
- Nosebleeds
- Neurologic signs such as wobbling or sensitivity to touch
Severe infections can damage blood vessels and tissues. Early treatment greatly improves outcomes.
Babesiosis
Babesiosis is caused by Babesia parasites of red blood cells that are transmitted by deer ticks and western black-legged ticks.
Signs in dogs may include:
- Weakness
- Pale gums
- Fever
- Dark urine
- Depression
- Enlarged lymph nodes
- Collapse in severe cases
Because the disease destroys red blood cells, many dogs become anemic and critically ill if untreated.
Cytauxzoonosis
Cytauxzoonosis is a severe disease caused by Cytauxzoon felis and spread mainly by the Lone Star tick.
Early warning signs in cats include:
- Loss of appetite
- Lethargy
- Difficulty breathing
- Pale gums
- Fever
- Increased heart or respiratory rate
- Pain or reluctance to be touched
As the disease progresses, cats may develop:
- Jaundice (yellow gums or eyes)
- Seizures
- Collapse
- Coma
Cytauxzoonosis can progress rapidly and may become fatal within days without prompt veterinary care.
How Pets Get Ticks
Ticks wait on grasses, shrubs, wooded trails, and brushy areas until an animal brushes past. This behavior is called “questing.”
Pets are especially at risk when:
- Hiking or walking through wooded areas
- Exploring tall grass or brush
- Spending time in areas with deer or wildlife
- Living in regions with high tick populations
Some ticks can even remain active during mild winter temperatures above freezing.
How to Protect Dogs and Cats from Tick-Borne Diseases
Prevention tips include:
- Use monthly or longer-acting veterinary-approved tick preventives
- Check pets daily after outdoor activities
- Keep pets on trails and out of dense brush
- Maintain short grass in yards
- Remove ticks promptly and correctly
- Ask your veterinarian whether Lyme vaccination is appropriate for your dog
Important reminder for cat owners: Never use dog tick products on cats. Some canine products are toxic to cats and may cause seizures.
How to Remove a Tick Safely
Experts recommend:
- Wear disposable gloves.
- Use fine-tipped tweezers or a tick-removal tool.
- Grasp the tick close to the skin.
- Pull straight out with steady pressure.
- Disinfect the area afterward.
Avoid home remedies such as petroleum jelly, nail polish, or burning the tick with a match, as these methods can increase disease transmission.
When to Call Your Veterinarian
Contact your veterinarian if your dog or cat develops:
- Fever
- Limping
- Weakness
- Loss of appetite
- Pale gums
- Swollen joints
- Vomiting
- Difficulty breathing
- Bruising or unexplained bleeding
- Sudden behavior changes after tick exposure
Early diagnosis and treatment are critical for many tick-borne diseases and can significantly improve outcomes.