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Short answer: Veterinary pathology is the study of disease in animals, practised in two professional tracks: anatomic pathology (tissue-based work) and clinical pathology (laboratory work on body fluids and cells). Individual pathologists earn board certification from the American College of Veterinary Pathologists (ACVP); diagnostic laboratories are separately accredited by the American Association of Veterinary Laboratory Diagnosticians (AAVLD).
Definition and scope
The ACVP describes itself as comprised of board-certified anatomic pathologists and clinical pathologists, and its journal, Veterinary Pathology, as a forum for original observations on the pathology of natural and experimental disease in animals (acvp.org, read 2026-11-08). That wording fixes the scope: both naturally occurring and experimentally induced disease, in animals, studied through two professional tracks.
Veterinary pathology sits inside the wider field described in what is veterinary science, and shares methods with human pathology. Its tissue-based half relies on techniques covered in the histopathology guide.
How the work is organised in practice
The clearest public description of how pathology services are organised in veterinary diagnostic laboratories comes from the AAVLD accreditation requirements (AC-1, version 2018-07, read 2026-11-08). Section 1.2 says an accredited laboratory must be capable of providing a full range of diagnostic services year-round in a majority of nine essential disciplines: necropsy, histopathology, clinical pathology, bacteriology, virology, mycology, parasitology, serology and toxicology. It is mandatory that a full-service laboratory offer necropsy, histopathology, bacteriology and virology on site, and mechanisms must exist for referral of services not directly offered.
Anatomic pathology
Anatomic pathology is the tissue-based track. In the AAVLD list, necropsy and histopathology are the two disciplines that fall here, and both are among the four that must be offered on site. Microscopy of sectioned tissue depends on instruments such as the microtome.
Clinical pathology
Clinical pathology is the track concerned with laboratory work on body fluids and cells. In the AAVLD list it is the third pathology discipline, but unlike necropsy and histopathology it is not one of the four mandatory on-site services, so a laboratory may refer it out. Related CASRAI pages cover veterinary cytology, the Hema 3 stain and the veterinary hematology analyzer comparison.
Cross-walk: AAVLD essential disciplines and where pathology sits
This table restates AAVLD AC-1 section 1.2 only. The grouping into pathology and other disciplines is an editorial reading of that list, not a classification the AAVLD document itself prints.
| Discipline (AAVLD 1.2) | Pathology service? | Mandatory on site for a full-service laboratory? |
|---|---|---|
| Necropsy | Yes (anatomic) | Yes |
| Histopathology | Yes (anatomic) | Yes |
| Clinical pathology | Yes (clinical) | No; referral allowed |
| Bacteriology | No | Yes |
| Virology | No | Yes |
| Mycology | No | No; referral allowed |
| Parasitology | No | No; referral allowed |
| Serology | No | No; referral allowed |
| Toxicology | No | No; referral allowed |
Who staffs pathology: qualifications and certification
AAVLD AC-1 Appendix 1 sets personnel expectations for anatomic and clinical pathology positions. Two routes are listed: a DVM (or equivalent veterinary degree) with an MS in pathology, or a DVM with completion of a pathology residency program, plus five years of veterinary diagnostic laboratory or relevant work experience; or a DVM with a PhD in pathology and ACVP diplomate status, plus five years. Exceptions are considered case by case. Technician roles in histotechnology, clinical pathology and necropsy are also listed.
The ACVP says certification is by a two-part examination leading to certification in veterinary anatomic or clinical pathology. As one example of a listed training program, Washington State University’s page on the ACVP site describes a three-year anatomic pathology residency with an MS and an option to continue to a PhD, and a three-year clinical pathology residency with a thesis master’s; graduates are described as eligible for ACVP certification. Other programs may differ.
Where it matters for labs, clinics and supply decisions
- In-house versus referred services. Under AAVLD AC-1, necropsy and histopathology are expected on site at a full-service accredited laboratory, while clinical pathology may be referred. Staff planning which instruments and consumables a laboratory needs should start from which of these services it actually performs.
- Subcontracting. AC-1 section 4.5.1 treats a subcontractor as competent if it complies with the AAVLD Requirements or with ISO 17025.
- Who gets reviewed. Section 2.1 says reviewed laboratories may be run by a state or provincial agriculture department, a university, an agricultural experiment station or a health department. The committee does not review commercial laboratories or laboratory animal diagnostic laboratories supported by the National Institutes of Health.
Decontamination questions that arise in tissue work are covered separately, for example in prion decontamination protocols. This page does not give necropsy or other procedure instructions.
Common misunderstandings
- ACVP certification and AAVLD accreditation are different things. The ACVP certifies individual pathologists; the AAVLD accredits laboratories.
- Absence from the AAVLD-accredited group does not describe quality either way. The AAVLD committee states that it does not review commercial laboratories or NIH-supported laboratory animal diagnostic laboratories, so their absence reflects scope, not a finding.
- Veterinary pathology is not only post-mortem work. The two tracks include clinical pathology, which works on body fluids and cells, alongside tissue-based anatomic pathology.
Frequently asked questions
What is the difference between anatomic and clinical veterinary pathology?
Anatomic pathology is the tissue-based track, including necropsy and histopathology. Clinical pathology is laboratory work on body fluids and cells. The ACVP certifies pathologists in either veterinary anatomic or clinical pathology.
Who certifies veterinary pathologists?
The American College of Veterinary Pathologists, through a two-part examination (acvp.org, read 2026-11-08).
Which pathology services must an AAVLD-accredited full-service laboratory offer on site?
Necropsy and histopathology, together with bacteriology and virology. Clinical pathology is among the nine essential disciplines but may be referred (AAVLD AC-1, version 2018-07, section 1.2).
Sources
- AAVLD, Requirements for an Accredited Veterinary Medical Diagnostic Laboratory, AC-1 Version 2018-07, hosted by USDA APHIS: aphis.usda.gov. Read 2026-11-08. This is the 2018-07 version.
- American College of Veterinary Pathologists: acvp.org. Read 2026-11-08.
- ACVP, Washington State University program overview: acvp.org training page. Read 2026-11-08.
