Veterinary Public Health

Hemorrhagic Gastroenteritis (HGE) in Dogs in 2009

Update: February 13, 2009

Graph of cases of HGE in dogs in 2009 through Feb 12 Map showing clustering of dogs with HGE in the western San Fernando Valley

Posted 2/13/09

Between January 1 and February 13, veterinarians in Los Angeles County at 13 veterinary practices reported 99 cases of either bloody or watery diarrhea in dogs. Of these cases, 82 also had vomiting. Half of the cases recover within five days and half take longer to recover or have a waxing and waning disease course. At least 29 cases required intravenous fluid treatment, while others required less intensive care. Most cases were treated by veterinarians with antibiotics and anti-nausea or anti-vomiting drugs.

Los Angeles County has an estimated 1.9 million dogs, so this outbreak is affecting a very small proportion of the population.

Outbreaks of bloody diarrhea in dogs were reported in four out of the five winters before 2009 in Los Angeles County, suggesting that seasonality may play a role.

There was no evidence to link this to the peanut-butter paste Salmonella outbreak. Salmonella cultures were reported on 12 dogs and all were negative. Tests for several other infectious agents were also performed, and did not reveal a clear answer. There is no evidence that any food contamination played a role, because the dogs had been eating a wide variety of foods.

In the majority of cases (89.5%), no other pet in the house was reported to have the same illness, so this condition did not appear to spread easily from dog to dog. This condition also did NOT appear to spread from dogs to people.

Most cases were reported from the San Fernando Valley area, with sporadic cases being reported from around the county. Veterinarians are encouraged to report cases through our reporting page in order to help better track patterns that may reveal a cause.

Printable version of update (PDF)

Hemorrhagic Gastroenteritis (HGE) and Watery Diarrhea Outbreak in Dogs

Pomeranian dog

Posted 2/5/09

Since January 21, 2009, Veterinary Public Health has received reports from several veterinary clinics that they were seeing an increasing number of dogs with watery and bloody diarrhea. As of January 30th, 2009, 53 official reports have been received, with an estimated 120 or more cases being seen at four veterinary clinics in the San Fernando Valley since January 1st.

The first 29 case reports were reviewed. The primary symptoms have been diarrhea (96.6 %) and vomiting (75.9%), with about half having bloody stool. Recovery rate has been variable, with about 20% having a waxing and waning of symptoms. The average age was 5 years, with a range of 2 months to 13 years. About half were small breed dogs.

Locally, increases in Canine Hemorrhagic Gastroenteritis (HGE) have been reported during the winters of 2004, 2005 and 2006. Veterinary Public Health gathered reports and tested many stool samples during previous outbreaks, but was not able to identify a definitive cause. With the clustering of reported cases, it is suspected that a contagious infection or food contamination may be causing these illnesses. Preliminary investigation of these cases, and similar cases from previous years, has not yielded any definitive evidence of bacterial or viral infection. Studies are on-going, but there is no evidence to date that this outbreak is linked to the current Salmonella outbreak in people.

Veterinarians who see potential cases of HGE are requested to report them through our reporting page, along with relevant laboratory reports. Please let us know if we can contact the dog owner to obtain additional information if needed. We may contact you about submitting stool specimens, as we attempt to determine the cause of the outbreak.

Many thanks to Dr. George Cuellar of the Southern California Veterinary Hospital and Dr. Nada Khalaf of VCA McClave Animal Hospital for reporting this outbreak. Participation by local veterinarians is essential to make our local animal disease surveillance effective, and such reports are a value to the entire animal health community.

2009 Canine Diarrhea and Hemorrhagic Gastroenteritis Information Sheet (PDF)