A rash of dead Redpoll birds in the South Cariboo has recently led to concerned residents and sick cats. The cause is likely salmonella, which also poses a health risk for humans.
Kim Rankin of 108 Mile Ranch found four dead Redpolls on March 29, and was worried enough about her cats and her parrot to call the Ministry of Environment.
She was told to freeze a couple of dead birds and turn them in for necropsy (wildlife autopsy), which Rankin did in early April.
Meanwhile, a blog by 100 Mile House veterinarian Pam Barker indicated it was likely salmonella causing the Redpolls deaths, Rankin explains.
“I just want the public to know because they are leaving out feeders from last year, and then the birds are transferring salmonella.
“I have brand new ones myself, and they were dying because they were obviously bringing it to the feeders, so I took mine down.”
Barker says Lakeland Veterinary Clinic has treated about a dozen sick cats this year, noting during any outbreak there are always many more sick cats out there not brought in.
She suspects the cause is salmonella – an infection Redpolls are susceptible to, carry and spread – due to symptoms seen in these cats.
“It's not a new, sudden epidemic; it happens every year. Some years just tend to be worse than others; this year, we seem to be having a more visible die-off.”
While it also is a health risk to other birds, dogs and humans, she notes cats are of particular concern because they hunt birds.
“The birds that are actually sick from salmonella, or dead from salmonella, are pretty easy victims.
“What we basically see, when the cats are coming in, is they're depressed, they're not eating, they're very lethargic and they're running a fever.
“There is essentially nothing we can do to cure them, there isn't an antibiotic or anything like that. We just give them supportive care and treat their symptoms until they recover.”
All of the cats this year have recovered, she notes, but several have been “very sick” for several days, so she recommends keeping cats away from bird feeders.
Barker adds bird droppings also carry salmonella so contaminate feeders as well as the seeds and ground under them, spreading the infection in Redpolls and other species.
Trudy Chatwin, species-at-risk biologist with the Ministry of Forests, Lands and Natural Resource Operations, says there has been a “noticeable increase” in dead birds, which led to a recent bulletin advising residents to take hygiene precautions with feeders and dead birds.
Chatwin adds these latest reports in the South Cariboo represent quite a “significant” number, and Rankin's dead Redpoll samples will be sent to the province's wildlife vet for analysis and necropsy.
“As to the transfer of whatever it is from the Redpoll to the cats, I couldn't confirm that at all. We won't really know until those birds have their necropsy.”
Several diseases can arise in spring conditions with the return of communal bird feeders, she adds.
“The one that we would be the most concerned about as to humans is the salmonella bacterium.”
Two other commonly seen problems are avian conjunctivitis and avian pox virus, which she believes primarily affect birds only.
Chatwin recommends strict hygiene, including using rubber gloves to dispose of dead birds and spilled seeds, and cleaning bird feeders thoroughly with a solution of water and 10 per cent vinegar.
Preventing squirrels from accessing feeders is also suggested, Chatwin explains, or removing feeders altogether if residents have cats or find any dead birds.
Barker adds taking down feeders might also be prudent when there is anyone in the house who is immune compromised and might also have contact with a cat.
There are specific signs to watch for in birds that appear sick to indicate what illness they might have.
To learn more, visit www.env.gov.bc.ca/wld/documents/wldhealth/sick_bird_fs.pdf.
Folks who find dead Redpolls in their yards are asked call the Ministry of the Environment in Williams Lake at 250-398-4530 and ask for Helen Schwantje.