Unlike the first event - which was linked to raw milk consumption - the second outbreak appears linked to commercial raw meat pet food.
Yesterday the LA County Health Department (animal health division) published the following AHAN - for veterinarians - on the second incident. This is a lengthy document, and I've only reproduced some excerpts, starting with the summary below.
Veterinarians in particularly will want to follow the link to read it in its entirety.
Animal Health Alert: H5 bird flu confirmed in four domestic cats that consumed recalled raw milk, and in one cat that consumed commercially produced raw pet food.
12.20.2024
Key Points:
- Five indoor-only, domestic cats in one household in Los Angeles (LA) County died after consuming recalled raw milk. Four of these cats were tested and confirmed to be infected with H5 Bird Flu. This group includes the two cats described in an earlier alert issued 12/12/2024.
- There are additional recalls on raw dairy products. The current recalls include:
- All sizes of raw milk and cream produced by Raw Farm, LLC in California betweenNovember 9-27, 2024 (lot numbers 20241109 through 20241127).
- All “Valley Milk Simply Bottle Raw Cow Milk” and “DESI Milk Raw Cow Milk” distributed in quart (32oz), half-gallon (64 oz), and one-gallon (128 oz) plastic judges with a code date marked on the container of “DEC 23 2024 through DEC 30 2024”, produced by Valley Milk Simply Bottled of Stanislaus County.
- From a separate household in LA County, a symptomatic cat has tested presumptive positive for H5 bird flu after consuming two different brands of raw pet food composed of raw poultry and raw beef. The investigation for this case is currently ongoing.
- Animal health staff should specifically ask pet owners about exposure to raw milk and raw diets, share information about the risk of raw milk and raw diets, and caution pet owners NOT to consume raw dairy products, nor offer them to pets.
- Animal health staff should wear appropriate personal protective equipment (PPE) when in contact with animals suspected or confirmed of being infected with H5 bird flu; acutely sick animals that have history of exposure to raw milk or raw milk products, wild birds or raw or undercooked animal products.
- Animal health staff are strongly recommended to receive their seasonal flu vaccine. Although this vaccine is not proven to prevent infection with H5 Bird Flu, it can help protect staff from seasonal human flu which is circulating right now.
- REPORT suspected cases of H5 bird flu in cats and other animals. Testing for the virus may be available. A complete dietary history for the animal (including raw dairy, raw poultry and/or meat, and bird exposure) is needed.
We get more details on the investigation (which includes 13 affected cats, with at least 7 deaths).
On 11/22/24, eight cats in one household were offered raw milk produced by Raw Farm, LLC. The raw milk was from a lot that was not included in the recalls issued on 11/24/24 and 11/27/24 but was included in the third recall issued on 12/3/24. Between November 20 and December 7, 2024, seven of the cats became ill. Between December 2-10, five died or were euthanized. The other two cats are under quarantine and improving.
This group includes the two cats described in an earlier alert issued on 12/12/2024. Clinical signs were variable but progressive. They included fever, lethargy, dehydration, anorexia, icterus, respiratory distress, and neurologic signs (primarily seizures, although one had nystagmus). One cat had evidence of lung lobe consolidation.
Of the five deceased cats that drank the recalled raw milk, four were tested for influenza A by PCR testing of samples from multiple body sites (oropharyngeal, rectal, and/or brain). All samples collected were confirmed positive for Influenza A, and further subtyped as H5N1 also known as H5 Bird Flu, by the National Veterinary Services Laboratory (NVSL).
These are the first confirmed cases of H5 bird flu infections in cats in Los Angeles County. They were sequenced by NVSL with sequences identical to the raw milk they ingested which was recalled from Raw Farms. H5 bird flu has been detected in domestic cats in other states since the beginning of this national and international outbreak that began in wild birds in late 2021.
From a separate household in LA County, Veterinary Public Health is investigating five indoor only domestic cats that became ill presumably after consuming two different brands of raw pet food diets composed of raw poultry and raw beef.
Approximately 2 weeks after consuming the raw diets, two cats presented with acute respiratory distress to veterinary clinics and were humanely euthanized. One of these cats had known pre-existing cardiac disease. Two other cats presented with symptoms including lethargy, reduced appetite, upper respiratory, neurologic, and ocular signs of disease. One cat was treated for corneal edema and uveitis in one eye. The other cat displayed ataxia, uveitis and bilateral retinal detachment in both eyes and was tested with a respiratory panel from a commercial veterinary diagnostic laboratory, which resulted as presumptive positive for Influenza A and Feline Calicivirus.
This sample was further detected as positive for H5 bird flu at the California Animal Health and Food Safety (CAHFS) Laboratory and the sample will be sent to NVSL for confirmation, subtyping, and sequencing. The investigation is ongoing and includes testing of the raw pet food diets by the Food and Drug Administration (FDA).
They report no evidence of cat-to-cat transmission or cat-to-human transmission, although we've seen some evidence of both with other avian flu viruses (see EID Journal: Avian H7N2 Virus in Human Exposed to Sick Cats).
They caution, however:
. . . people who come into close contact with animals, especially wild birds and their feces, infected cats, infected poultry, or with infected dairy cattle or their milk, have a higher level of risk of exposure. It is important to take proper precautions.
For more on HPAI H5 in domestic cats, you may wish to revisit:
Emerg. Microbes & Inf.: Marked Neurotropism and Potential Adaptation of H5N1 Clade 2.3.4.4.b Virus in Naturally Infected Domestic Cats
Eurosurveillance: (HPAI) H5 virus Exposure in Domestic & Rural Stray Cats, the Netherlands, October 2020 to June 2023
ECDC Risk Assessment: Avian influenza in domestic cats - Poland - 2023
Eurosurveillance: Asymptomatic infection with clade 2.3.4.4b HPAI A(H5N1) in carnivore pets, Italy, April 2023