How do dogs become ill from ticks? - briefly
When a tick attaches and feeds, it injects bacteria, protozoa, or viruses that multiply in the dog’s bloodstream, causing illnesses such as Lyme disease, ehrlichiosis, or anaplasmosis. Transmission generally requires the tick to remain attached for several hours, permitting the pathogen to be transferred.
How do dogs become ill from ticks? - in detail
Ticks attach to a dog’s skin, insert their mouthparts, and feed on blood for several days. During this process they can introduce pathogens directly into the bloodstream. The primary routes of infection are:
- Salivary transmission – pathogens present in the tick’s saliva are injected while the insect pierces the skin.
- Regurgitation – contents of the tick’s gut may be expelled into the wound during feeding.
- Contamination of the bite site – infected tick feces can enter the wound when the animal scratches.
Once inside the host, the microorganisms multiply and spread, producing clinical disease. The most common tick‑borne illnesses in dogs include:
- Lyme disease – caused by Borrelia burgdorferi; symptoms range from lameness and joint swelling to fever and kidney dysfunction.
- Ehrlichiosis – Ehrlichia canis or Ehrlichia ewingii infection; leads to thrombocytopenia, anemia, weight loss, and occasional neurologic signs.
- Anaplasmosis – Anaplasma phagocytophilum or A. platys; produces fever, lethargy, and platelet depletion.
- Babesiosis – Babesia spp.; results in hemolytic anemia, jaundice, and possible organ failure.
- Rickettsial diseases – such as Rocky Mountain spotted fever; cause fever, skin lesions, and vascular inflammation.
- Tick paralysis – neurotoxic protein secreted by certain tick species; induces progressive weakness, ataxia, and potentially respiratory failure.
Pathophysiology varies by agent. Bacterial infections often trigger immune‑mediated inflammation of joints, blood vessels, or renal tissue. Protozoal parasites invade red blood cells, causing hemolysis. Viral agents may suppress immune function, increasing susceptibility to secondary infections. In tick‑induced paralysis, the neurotoxin blocks acetylcholine release at neuromuscular junctions, impairing muscle contraction.
Diagnosis relies on a combination of clinical assessment, laboratory testing, and identification of the tick species. Blood smear examination can reveal intra‑erythrocytic parasites; polymerase chain reaction (PCR) and serologic assays detect bacterial DNA or antibodies. Removal of the attached tick and observation of symptom resolution also aid in confirming tick paralysis.
Treatment protocols differ by disease:
- Antibiotics – doxycycline is first‑line for most bacterial infections, administered for 2–4 weeks.
- Antiprotozoal drugs – imidocarb dipropionate or diminazene aceturate for babesiosis.
- Supportive care – fluid therapy, blood transfusions, and analgesics for severe anemia or organ dysfunction.
- Tick removal – prompt extraction with fine‑pointed tweezers, followed by monitoring for paralysis resolution; in severe cases, antitoxin administration may be required.
Prevention focuses on reducing tick exposure and interrupting pathogen transmission. Strategies include:
- Regular application of acaricidal collars, spot‑on treatments, or oral preventatives.
- Routine inspection of the coat after walks in tick‑infested areas, with immediate removal of any attached specimens.
- Landscape management to lower tick habitat around the home, such as clearing tall grass and applying environmentally safe acaricides.
- Vaccination against Lyme disease where available and recommended.
Understanding the mechanisms of tick‑borne disease transmission enables timely intervention, minimizes clinical impact, and supports effective preventive measures for canine health.