Canine Herpesvirus (CHV-1) in Dogs: Symptoms, Treatment & Prevention

Canine herpesvirus-1 (CHV-1) is a ubiquitous alphaherpesvirus. Most adult dogs are latently infected (seroprevalence 40–90%). It's usually mild in adults but devastating in neonates. Understanding the lifecycle guides prevention.

Transmission

• Oronasal, venereal, transplacental, aerosols.
• Virus shed in secretions (oral, nasal, vaginal) for 1–2 weeks post-infection; reactivates with stress/immunosuppression.
• Environmentally fragile: dies quickly outside host (heat, drying, disinfectants).

Clinical Presentation

Neonates (0–3 weeks) — "Fading Puppy Syndrome"

• High mortality (up to 80% in naive litters).
• Non-specific: crying, weakness, anorexia, abdominal pain, dyspnea, hemorrhagic diarrhea, petechiae.
• No respiratory signs typically (unlike adults).
• Death within 24–48 hrs of onset.

Adults

• Often subclinical.
• Mild upper respiratory: cough, sneeze, serous nasal discharge.
• Ocular: conjunctivitis, keratitis, dendritic ulcers.
• Reproductive: vesicular vaginitis/balanoposthitis, infertility, abortion, stillbirth, weak puppies.

Diagnosis

• PCR (swabs, tissue) — gold standard, detects viral DNA.
• Virus isolation (less common).
• Serology (paired titers) — indicates exposure, not active disease.
• Necropsy + histopathology (inclusion bodies) for neonatal losses.

Treatment

• Neonates: Warming is critical — CHV-1 replicates at 35–37°C; core temp >38°C inhibits replication. Incubator 95–100°F. Antivirals (acyclovir, vidarabine) — limited efficacy, supportive care primary.
• Adults: Supportive (fluids, nutrition). Topical antivirals for ocular lesions. Antibiotics if secondary bacterial infection.

Prevention & Breeding Management

• Vaccine (Eurican Herpes 205 / Nobivac CHV): Inactivated subunit. Two doses: 1) During heat or 7–10 days post-mating; 2) 6–7 weeks gestation. Boosts maternal antibodies → colostral protection for puppies. Does not prevent infection, reduces severity/shedding.
• Isolate pregnant dam last 3 weeks gestation + first 3 weeks postpartum.
• Strict hygiene: disinfect whelping area (bleach 1:32, accelerated hydrogen peroxide).
• Avoid contact with unknown dogs during high-risk periods.
• Stud dogs: test/screen; consider semen PCR if high-risk program.

Key Takeaway

CHV-1 is a management disease. Vaccination + thermal support for neonates + dam isolation = best outcomes. Work closely with a reproduction-savvy veterinarian.