We deliver a full cytology service for both small animals and equine.

This is provided by our on-site American and European boarded clinical pathologists.

Cytology is often used for its quick and easy collection method and fast turn-around time. Our cytology service also includes some specialist areas such as ocular cytology and bone marrow cytology.

Clinical Pathologists

Jennifer Stewart BS, DVM, DipACVP (Anatomic & Clinical), MRCVS , Anatomical and Clinical Pathologist


As with our histology service, the use of special stains is available, and may be performed at the pathologist’s discretion or via direct request.

Samples may be submitted as air-dried smears or fluid for processing. In order to provide the most useful interpretation of fluid samples cell counts from a manual counting chamber and total protein by the most appropriate method are routinely included in our cytology reports when sufficient sample volume is provided.

We also offer our specific equine respiratory cytology which includes the unique inflammation score developed by our equine epidemiology team. This inflammation score eases comparison between serial samples when monitoring improvement.

  • Clinical history and location are vitally important in interpreting cytologies, given the absence of surrounding architecture for orientation. In their absence many cases are un-diagnosable. Submission forms should be filled in any parts and slides should be appropriately labelled (name/number patient, site of aspiration).
  • Exposure to formalin of any kind renders samples un-‘readable’ via traditional Romanowsky stains. This includes formalin fumes; therefore cytology samples should be sent in a separate, sealed bag from any biopsy specimens.
  • In cases where fluid samples may require prolonged storage prior to shipment or storage a drop or two of formalin may be added to aid with preservation – please note this on the submission form for the lab so an alternative stain may be used for assessment. Since cells deteriorate after long staining in a fluid, a few fresh direct smear of the effusion should also be made and sent together with the fluid sample.
  • In cases where bacterial culture of a fluid may be required, a separate sample (in a plain tube) should be provided.
  • Bone marrow aspirates should always be sent together with a peripheral blood sample taken at the same time. In absence of peripheral blood evaluation, bone marrow interpretation is frequently not possible.

For specific enquiries about our clinical pathology services, please contact  Kate Irvine or Jennifer Stewart.

AHT Equine Infectious Disease Service

The Animal Health Trust (AHT) is extremely grateful to the Horserace Betting Levy Board (HBLB), Racehorse Owners Association (ROA) and Thoroughbred Breeders’ Association (TBA) for their continued combined contribution to the AHT’s Equine Infectious Disease Service, which in particular supports key staff within the Diagnostic Laboratory and Pathology Service and allows enhanced investigation and control of significant equine infectious diseases in the United Kingdom.