Queen Mother Hospital for Small Animals

Royal Veterinary College photo

Researchers at the Queen Mother Hospital for Animals, associated with the Royal Veterinary College in London, are investigating a spike in cases of feline pancytopenia, a condition in which all major blood cell types are severely reduced.

More than 130 cats in the United Kingdom have been afflicted in recent weeks by pancytopenia, a rare and often fatal blood condition that has investigators suspecting that something in particular dry cat foods may be to blame. In response, the company behind the implicated foods issued a nationwide recall Tuesday of 21 varieties of diets.

The Royal Veterinary College in London confirmed today that veterinarians are exploring an association between the cases and food fed to the cats. "Based on the evidence to date, the one aspect of these cases that formed a consistent pattern was the diet of the affected individuals," the RVC said, noting that researchers have data relating to diet from about 80% of cases. 

More data, however, is needed, researchers say. They're appealing to practitioners seeing pancytopenia cases to respond to a survey. "[W]e are keen to identify a common denominator (e.g., toxic, infectious causes, etc.). We will share our findings as soon as is practically possible so that the vet community can instigate positive interventions," an RVC announcement reads.

Coincidentally, veterinary researchers in Ontario, Canada, similarly are appealing to clinicians for input as they attempt to track an uptick of severe respiratory disease that has surfaced recently in the local dog population. Dr. Scott Weese, an infectious disease expert, and colleagues at the University of Guelph, ask that veterinarians seeing cases of dogs with upper respiratory tract infections in Ontario and beyond respond to a survey. 

The feline pancytopenia research in the U.K. is led by Dr. Barbara Glanemann, a senior lecturer and co-head of the Small Animal Internal Medicine Service, and Dr. Karen Humm, associate professor in transfusion medicine and emergency and critical care. Neither could be reached for comment.

An article published May 25 and updated this week by the RVC provides some details about what concerns veterinarians. 

"Typically, we may see one case of this per year, but we have seen now 10 cats with severe pancytopenia (consisting of severe leukopenia, thrombocytopenia and anaemia) in the last four weeks," Glanemann said in an interview with the college. "… Given the rarity of this condition, the clustering of these cases is concerning."

Pancytopenia, a sometimes fatal condition marked by low numbers of red blood cells, white blood cells, and platelets, usually indicates an underlying cause, such as exposure to a bone marrow suppressing drug or a toxicant. Thus far, an underlying cause has not been identified.

Initial signs can include lethargy, malaise, and lack of appetite. Patients might also spontaneously bleed, including from the mouth, and may show bruising.

Some of the sick cats came from the same household. After reaching out to colleagues, Glanemann said she became aware of another 40 to 50 similarly afflicted cats. "The cats are severely unwell, have spontaneous bleeding and require multiple transfusions for stabilization prior to any investigation being possible," she said in the article.

The potential link between the cases of pancytopenia and specific diets was revealed Tuesday when the Food Standards Agency issued a notice that U.K. manufacturer Fold Hill Foods would recall some dry cat food products because of safety concerns.

Fold Hill Foods manufactures dry cat food diets for the supermarket chain Sainsbury's, and the AVA and Applaws brands. In response, Sainsbury's and Pets at Home, a national pet store chain, have pulled the diets from store shelves. 

"We are voluntarily recalling the dry products we manufacture … as a precautionary measure," reads a statement on the Fold Hill Foods website. "We are supporting an investigation by the food and veterinary authorities into a possible safety issue affecting cats."

Cat owners who have the recalled food at home are instructed to return the food to the store where it was purchased for a refund; no receipt necessary.

Canine respiratory disease rears in Ontario

Meanwhile in Canada, a severe form of canine respiratory disease is sickening an attention-getting number of dogs, some fatally.

That alert came Monday from Weese, the zoonotic disease expert in Ontario. In a a post on his blog Worms and Germs, Weese said he's fielding concerns about canine infectious respiratory disease complex (CIRDC). Commonly known as kennel cough, reports of CIRDC aren't necessarily cause for concern, Weese points out. "Sometimes, they're just a result of increased awareness of the normal 'baseline' disease rate, since 'kennel cough' is always occurring at some level," he writes.

Then he adds: "Sometimes, the circumstances just seem different, and we need to get more information. [That] is where I stand at the moment. ... My impression is that something unusual is happening."

In an interview, Weese said the reports he's fielded are of dogs with typical but severe respiratory signs: runny eyes and nose, coughing and fever. "I've been getting calls for the last two weeks, and there have been a good handful of deaths," he said.

Weese declined to quantify the number of afflicted dogs, saying it's too early to tell. He's still trying to determine whether the suspected disease outbreak isn't an outbreak of disease awareness.

At least nine different viral and bacterial pathogens have been linked to CIRDC, including canine influenza virus, canine parainfluenza virus, canine respiratory coronavirus and Bordetella bronchiseptica. All spread rapidly among dogs in close contact.

"Most often, it's the usual suspects, one of four or five potential things that it could be," Weese said. "Canine influenza is not active right now in North America, but it's always a concern, and canine parainfluenza is the most common."

Getting a handle on what's happening can be difficult because infections may resolve on their own or with treatment without diagnostic testing to determine the source of illness. For that reason, Weese and his colleagues at the University of Guelph are relying on a survey to collect information on dogs with upper respiratory tract infections in Ontario and beyond. 

"This is how we identified canine flu in 2017 and 2018. We were able to find it and eradicate it," Weese said. "Informal surveillance can be really useful."

The survey asks whether a patient has typical respiratory symptoms — eye and nose discharge, trouble breathing, coughing, decreased appetite — and to characterize the severity and duration of symptoms. The survey also asks whether the dog has been vaccinated for kennel cough or exposed to COVID-19.

"COVID-19 is not something we're worried about; we're just asking," Weese said. "Right now, I've only got a handful of responses, but one dog park has come up a couple of times. This is how we're going to figure out if something usual is happening and what that might be."

In instances such as the U.K. feline pancytopenia outbreak and the Ontario canine respiratory disease flare, the fact that the veterinary profession is a well-connected, tight-knit community is valuable, observed Dr. Stijn Niessen, a consultant for the Veterinary Information Network, an online community for the profession and VIN News Service parent.

For example, he said, "everyone" is talking about feline pancytopenia and what might be causing the cases.

"So this shows the value of a connected community of veterinarians that can act rather quickly to figure out that, A, there is something going on, and then, B, trying to find answers about what is going on and then, C, trying to fix it," Niessen said. "Hopefully, the connectivity of the community is actually saving lives."

Update: The number of cats in the U.K. known to be afflicted by pancytopenia has climbed to 528, with a 63.5% mortality rate, according to an Aug. 2 update from the Royal Veterinary College. Reported incident rates, however, have dropped sharply from a peak in mid-June. Mycotoxins, naturally occurring toxins produced by certain molds, were identified in a small number of samples of the recalled cat food, according to a July 16 regulatory announcement, but it's unclear whether they caused the pancytopenia. Investigations are continuing.