Cancer misdiagnosis may be common in English bulldogs

Research out of CSU suggests a high B-cell count does not necessarily indicate cancer in English bulldogs, Morris Animal Foundation reports

English bulldogs thought to have cancer may, in fact, have a non-cancerous syndrome called polyclonal B‐cell lymphocytosis, according to Morris Animal Foundation-funded research out of Colorado State University. Photo ©BigStockPhoto.comSome English bulldogs diagnosed with common cancer might not have the disease at all.

This is according to newly published Morris Animal Foundation-funded research out of Colorado State University (CSU).

While conducting a study to better understand B-cell chronic lymphocytic leukemia (BCLL), researchers discovered English bulldogs thought to have cancer may, in fact, have a non-cancerous syndrome called polyclonal B‐cell lymphocytosis.

“This could save some dogs from being misdiagnosed, treated for cancer, or even euthanized when they shouldn’t be,” says Anne Avery, PhD, VMD, a professor in the university’s department of microbiology, immunology, and pathology. “The dogs may look to their veterinarians like they have leukemia based on original diagnostics, but they don’t actually have cancer.”

In a previously published paper, Dr. Avery and her team identified breeds with an increased risk for BCLL. English bulldogs were among those noted, but had a unique presentation as compared to the other breeds, Morris Animal Foundation reports.

For one, English bulldogs were significantly younger when they presented. Further, they had differences in what their B-cells (i.e. antibody-producing white blood cells) expressed on the cell surface when analyzed by flow cytometry, according to Morris Animal Foundation. This difference led researchers to wonder if the dogs truly had BCLL or a different, previously unidentified disease.

For the newly published retrospective study, the team at CSU looked at a database of 195 English bulldogs and identified 84 cases with increased numbers of B-cells in the blood. Researchers analyzed the serum of these dogs to determine the types of antibodies they produced. Additionally, because many of the animals had enlarged spleens, the team also looked to see what kinds of cells expanded there.

An assay was performed to determine if the B-cells were identical or not. If identical, it would suggest they arose from a single cell and likely would have been cancerous, Morris Animal Foundation says.

The team determined 70 per cent of the dogs did not have cancer. Those in this group tended to be young, some only a year or two old, when they developed the syndrome. Additionally, 75 per cent of the dogs were male and more than half had enlarged spleens. Further, most of the cases had hyperglobulinemia, an excess of antibodies in the blood stream.

Researchers hypothesize this syndrome has a genetic basis.

“This important finding demonstrates we shouldn’t assume a high B-cell count always indicates cancer in English bulldogs,” says Morris Animal Foundation’s chief scientific officer, Janet Patterson-Kane, B.VSc., PhD, FRCVS. “This is very important information for veterinarians who may initially see these patients in their clinic.”

Researchers looking for evidence of this syndrome in other breeds, but believe it to be rare in dogs other than English bulldogs, Morris Animal Foundation reports.

The findings have been published in the Journal of Veterinary Internal Medicine. To access the report, click here.

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