Uncovering the role of erythrocyte sedimentation rate as an inflammatory marker

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The erythrocyte sedimentation rate (ESR) is a blood test used to measure inflammation in the body. In veterinary medicine, the ESR is mainly used as an inflammatory marker and monitoring parameter in conditions such as osteoarthritis and tick-borne diseases in dogs.

Although research about the use of ESR in canines is abundant, information regarding the use of ESR in felines is limited. However, a recent study in Veterinary Medicine International indicates that ESR could be useful to assess inflammatory markers in cats.

Using ESR

Red blood cells (RBCs) contain glycoproteins that have a negative electric charge and create a repulsion effect between cells. During inflammation, the protein composition in RBCs changes, which disrupts the electric charge and causes RBCs to stick to each other, leading to an increase in ESR. In the past, the use of the ESR in animals was limited using the Western Method because a large volume of blood was required; the turn-around time for results was long.

The MINI-PET is an automated continuous-loading instrument for the ESR that has recently been validated for use in dogs and horses. This tool has a quick turn-around time of 14 minutes, requires small blood samples, and displays results on the device. This device is more convenient for determining ESR in veterinary medicine.

Studying ESR

This study’s main goals were to define the ESR reference interval (RI), compare ESR values between healthy and sick cats, evaluate relationships between the ESR and some inflammatory markers used in feline practice, and assess ESR changes in different durations of illness (acute, chronic, or acute-on-chronic).

This prospective multicentric cohort study enrolled 200 client-owned felines: 57 healthy cats and 143 ill cats. Cats were classified as having acute, chronic, or acute-on-chronic conditions. The investigators measured ESR with MINI-PET using the same K3-EDTA tubes that are used for CBCs. The total leukocyte count (WBC), neutrophil-to-lymphocyte ratio (NLR), fibrinogen, serum amyloid A, and albumin/globulin ratio (A/G) were measured.

The study results showed that ill cats had a significantly higher ESR (median 29 mm/h; range 12–46 mm/h) than that in healthy cats (median 10 mm/h; range 1–12 mm/h). The ESR positively correlated only with fibrinogen. Cats with acute-on-chronic diseases had the highest ESRs (median 47 mm/h; range 35–56 mm/h) compared with acute (median 16 mm/h; range 14–42 mm/h) and chronic cats (median 14 mm/h; range 10–31 mm/h).

Takeaways

Overall, the study demonstrated that the ESR can be used to assess inflammation in cats with acute diseases. ESR was consistently elevated in cats with acute-on-chronic diseases which indicates it may be more useful in this population. Using the MINI-PET is considered an inexpensive and easy method to measure the ESR.

An official RI for the feline ESR has not been published yet. Further studies may be needed to investigate the use of the ESR in cats.

Nicola Wood is a 2025 PharmD candidate studying veterinary pharmacy at the University of Connecticut in Storrs.

Reference

Gori E, Pasquini A, Paltrinieri S, et al. Prospective Application of the erythrocyte sedimentation rate (ESR) as a possible inflammatory marker in feline patients. Vet Med Int. 2024;2024(4):2313447. doi:10.1155/2024/2313447