How does an encephalitis tick manifest in a dog? - briefly
Infected dogs typically show fever, reduced appetite, and progressive neurological signs such as ataxia, tremors, seizures, and facial nerve paralysis. Diagnosis is confirmed by laboratory analysis of blood or cerebrospinal fluid for the tick‑borne encephalitic pathogen.
How does an encephalitis tick manifest in a dog? - in detail
Tick‑borne encephalitis in canines begins with an incubation period of 5‑21 days after a bite from an infected Ixodes species. The virus then spreads hematogenously to the central nervous system, producing a biphasic disease course.
During the first phase, dogs may exhibit fever, lethargy, loss of appetite, and mild musculoskeletal discomfort. These nonspecific signs often resolve spontaneously, creating a false sense of recovery before the second, neurologic phase emerges.
The neurologic phase is characterized by:
- Ataxia affecting fore‑ and hind‑limbs, often asymmetrical
- Tremors or myoclonus of the head, neck, and limbs
- Cranial nerve deficits, such as facial paralysis, reduced blink reflex, or dysphagia
- Hyperesthesia, manifested as heightened sensitivity to touch or sound
- Seizure activity, ranging from focal twitching to generalized convulsions
- Altered mentation, including disorientation, stupor, or coma in severe cases
Concurrent systemic manifestations may include vomiting, diarrhea, and mild respiratory distress, reflecting viral dissemination beyond the brain.
Diagnostic work‑up relies on:
- Detailed history of outdoor exposure in endemic regions
- Physical and neurologic examination documenting the above deficits
- Laboratory testing: complete blood count (often showing mild leukocytosis), serum biochemistry (possible hepatic enzyme elevation), and cerebrospinal fluid analysis revealing pleocytosis with a lymphocytic predominance
- Serologic assays detecting specific IgM/IgG antibodies against tick‑borne encephalitis virus, with paired samples confirming seroconversion
- Polymerase chain reaction (PCR) on blood or CSF when available, providing direct viral identification
Therapeutic management is supportive:
- Intravenous fluid therapy to maintain hydration and electrolyte balance
- Anticonvulsants (e.g., phenobarbital or levetiracetam) for seizure control
- Anti‑inflammatory agents such as dexamethasone to reduce cerebral edema, administered under veterinary supervision
- Nutritional support and passive warming to counteract hypothermia
Prognosis varies with disease severity and promptness of intervention. Mild neurologic involvement may resolve within weeks, leaving the animal neurologically intact. Severe cases with extensive CNS damage can result in permanent deficits or fatality despite aggressive care.
Prevention focuses on tick control: regular application of acaricidal products, environmental management to reduce tick habitats, and vaccination where licensed formulations exist for canine use in endemic areas.