VMD 513: Pet animal Breeding, Management, Nutrition and Health Care (1+1)

HERPES VIRUS INFECTION

• Herpes viruses are known to be pathogens for domestic poultry and account for diseases such as infectious laryngotracheitis, duck virus enteritis and Marek’s disease, few herpes virus infections of exotic and caged birds have been described.
• Herpes virus infections have been described in raptors, parrots, pigeons, cranes.
• In psittacines three distinct Herpes virus infections have been reported.
• Pacheco’s disease is best known, but there are descriptions of an infectious laryngotracheitis like herpes virus that affect Amazon parrots and of a herpes virus of Budgerigars that is harbored predominantly in the feathers and may cause decrease hatchability of eggs.
• Transmission is mainly by latent infection.

Clinical signs

• Clinical signs in affected pigeons are listlessness, loss of appetite, dyspnea, ocular and nasal discharge.
• The disease cause mortality up to 50% and is most severe in birds less than 6 months of age.
• Pigeon herpes encephalomyelitis virus showed nervous signs before death.
• Depression, inappetence and inability to fly were followed by paresis and paralysis of extremities.
• Head tremor, circling movement, torticollis and greenish diarrhea were also observed.
• With Pacheco’s disease the signs of illness vary to some degree with the species of psittacines affected.
• Smaller psittacines (lovebirds, parakeets, pionus spp.), amazons and cockatoos often die acutely after showing minimal signs of illness.
• They continue to eat and drink and may be obviously weak and listless for only a matter of hours prior to death.
• Some larger psittacines, especially macaws, may become visibly ill, exhibiting lethargy, regurgitation and diarrhea with a distinctive orange coloration.
• These birds may also show increase thirst, and some may recover.

Treatment and control

• No vaccines are available for the known herpes virus infection of caged and aviary birds.
• Since the different herpes viruses are serologically distinct, vaccination with the products designed for poultry would be of little value for aviary birds.
• With out the benefit of vaccines, the aviculturist may rely on strict sanitation and good husbandry procedures to prevent or control herpes viral infections.
• Stressful condition such as overcrowding must be avoided.
• Food and water containers should be covered to minimal fecal contamination.
• Daily washing and disinfection of dishes should be done, with care taken to return them to the cages from which they come.
• Since healthy carrier birds may introduce disease, new birds should be acquired from trusted sources only and quarantined 2-4 weeks before introduction to an established aviary.