When Man's Best Friend Becomes Public Health's Nightmare: Asymptomatic Puppies Test Positive for Rabies Following Exposure to Rabid Littermate

BACKGROUND: On June 12, 2015, the Iowa Department of Public Health (IDPH) received a call from a veterinary office reporting a positive rabies test on a 9 week old puppy (index puppy).  The index puppy had been purchased at 8 weeks of age from an unlicensed breeder on May 31, became ill on June 7, and was euthanized due to illness on June 9.  Littermates were housed with the index puppy for three days during the index puppy’s infectious period. The entire litter was housed together from birth, so it is very likely that the littermates were also potentially exposed to the animal that infected the index puppy. There were seven puppies in the litter, including the index puppy, and all were healthy when sold on May 31.  The only other animal that the puppies had direct contact with prior to being sold was their mother, and the puppies were weaned at 6 weeks of age.  No potential rabies exposures were reported by the breeder.

METHODS: Persons in contact with the index puppy were evaluated for saliva exposure. After consultation with CDC, it was determined that the mother of the litter should be boosted and isolated for 6 months and all puppies in the litter should be euthanized and tested for rabies. IDPH contacted the owners of the index puppy’s six littermates and recommended that all six be euthanized and tested at the State Hygienic Laboratory in Iowa. 

RESULTS: Rabies post-exposure prophylaxis (PEP) was recommended for 22 persons exposed to the index puppy. Despite all six of the littermates being healthy at the time of euthanasia, two of the six littermates tested positive for rabies via direct fluorescent antibody testing. The littermates that tested positive for rabies lived in neighboring states, and persons in contact with the animals were evaluated for saliva exposure and recommended rabies PEP, as necessary.   

CONCLUSIONS: Euthanasia and rabies testing should be considered for littermates, even if they are asymptomatic.