Charles Louis Davis and Samuel Wesley Thompson DVM Foundation

For the Advancement of Veterinary and Comparative Pathology | Phone: 847-367-4359 | Fax: 847-247-1869
  • 2018 General Pathology Review

    Join us for an intensive 4-day session on concepts in general pathology.

  • 2018 Northeast Veterinary Pathology Conference

    Dr. John Cullen will be speaking on Parenchymal Diseases of the Liver.

  • 2018 Annual Gross Pathology Review Course

    Learn all about gross lesions in domestic, laboratory, and exotic animals.

  • 2018 Descriptive Pathology Course

    Brush ​​up ​​your ​​descriptive ​​​​skills ​​in ​​a ​​supportive environment.

  • Prof. Maja Suter Awarded Coveted Olafson Medal

    This medal has only been awarded 13 times since 1980 to eminent veterinary pathologists. It is highly fitting that Maja Suter is the first female recipient of the Olafson Medal.

  • Student Scholarship Awards

    The Foundation proudly awarded deserving residents and graduate students at the 2017 ACVP Annual Meeting.

  • 2017 Southcentral Division Meeting

    The meeting was held at Texas A&M Galveston Campus in October, 2017. Annual dinner at Landry's!

  • IV Chilean Meeting on Veterinary Histopathology

    It was organized by Dr. Carlos Gonzalez from Andres Bello University, and sponsored by the Latin Comparative Pathology Group (the Latin-American Division of the Foundation).

Most Requested Publications

We are currently having problems with our bookstore, and we are sorry for the inconvenience. Please call the Main Office at 847-367-4359 to place all orders, and they will be shipped immediately. This problem should be resolved within the month.

CE Portal

Course ID: 166506
Title: Diseases of Marine Mammals

Length: 02:00:00
Author: Judy St. Leger, DVM, DACVP, SeaWorld Parks and Entertainment.
Description: This 2-hour lecture on diseases of marine mammals covers the gross morbid anatomy and various pathologic conditions affecting marine mammals.

Noah's Arkive

The Foundation is proud to make Noah's Arkive, a searchable collection of veterinary pathology images, available online at no cost. Special thanks to the University of Georgia for transferring the database and image collection to the Foundation!

Random Image:

CL Davis Diagnostic Exercises

The main goal of these Diagnostic Exercises is to provide interesting cases, focusing on the gross pathological lesions and associated histopathologic or cytologic findings. This material can be of great use for veterinary students, in-training pathologists, and ACVP diplomates alike.

There will be one contribution per month of the year; anyone may contribute. To do so, please contact Dr. Vinicius Carreira at to identify a convenient date for your submission and to receive templates to be used. Spots will be filled out on a first-come first-served basis.

Exercise Thumbnail Answer
Click here for case history Click here for case synopsis

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New today inNoah from Rahul Dange of UC Davis.

Tissue from two near term aborted fetuses (Calves #1 and #2)

Morphologic diagnosis:


Comment: New and interesting facts about EBA (other than the ones included in the JPC description in below link): - Causative agent: Pajaroellobacter abortibovis, a Deltaproteobacterium transmitted by Pajaroello tick (excellent name, based on the tick name and bovine abortion!)
- Distribution: Mexico, CA, NV & OR - Up to 90% fetal mortality (1st exposure to ticks). Subsequent gestation in the previously aborted cow may not produce an abortion due to active immunity - Window of susceptibility (60-140 days gestation)
- The bacteria replicates in macrophages of the infected pregnant cow without triggering an immune response or disease in the cow. Bacteria infects the placenta and fetus. The mature immune response of the fetus (developed in last term of gestation) causes extensive damage and destruction of various fetal organs, triggering an abortion - Confirmatory test, histopathology paired with a positive EBA serology and/or IHC

1. K. Clothier, M. Anderson, Evaluation of bovine abortion cases and tissue suitability for identification of infectious agents in California diagnostic laboratory cases from 2007 to 2012, In Theriogenology, Volume 85, Issue 5, 2016, Pages 933-938.
2. I. Chen. Saving California's calves. Science, 348 (May 2015), pp. 626-627.

VSPO Link:
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New today in Noah from Drs. Fabrizio Grandi and Aline Saco.

Tissue from a ten-year-old mixed breed dog.

Morphologic diagnosis: Gross: Severe cutaneous atrophy with comedone formation and pustular dermatitis. Histo: Mild, diffuse, hyperplastic and perivascular, lymphoplasmacytic dermatitis with superficial dermal splitting and comedone formation

Cause: Prolonged exogenous corticosteroid application

Comment: This patient had a history of chronic allergic dermatitis. The owner decided to apply a topical cream containing betamethasone valerate.

Topical corticosteroid reaction is a relatively common,
but markedly under-diagnosed syndrome that is associated with the inappropriate, localized use of potent
topical corticosteroid-containing creams (triamcinolone and betamethasone) The epidermis is mildly to moderately acanthotic and has a scalloped appearance to the lower border.

Splitting through the attenuated superficial dermis is common and in some cases may be an artifact of handling and processing the extremely fragile tissue. There is variable inflammation, including superficial pustules and pustular folliculitis. Chronic mixed inflammation may encircle blood vessels and adnexa, and is composed of neutrophils, histiocytes, lymphocytes, and plasma cells. Variable comedones can be seen as in hyperglucocorticoidism. Histologic findings are distinctive, particularly the pronounced dermal collagen attenuation with splitting. In
lesions lacking these features, the scalloped epidermal
border in the setting of follicular atrophy and/or comedones is highly suggestive.

Clinical and Histopathologic Diagnosis. 2005.
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New today in Noah from the AFIP Archive.

Tissue from a pig.

Morphologic diagnosis: Multifocal to coalescing superficial necrotizing colitis

Cause: Brachyspira hyodysenteriae

Name the condition: Swine dysentery

Comment: Swine dysentery (SD) generally affects pigs during the grow-finish phase of production. It causes a mucohemorrhagic diarrhea of the colon, and it can cause serious economic setbacks in a herd of pigs. SD is caused by Brachyspira hyodysenteriae, a gram-negative, beta-hemolytic anaerobic spirochete. Similar lesions may be caused by B. hampsonii. At least 4 other intestinal spirochetes have been identified in swine; B. pilosicoli can cause a mild colitis in pigs.

Gross lesions for SD are normally present only in the large intestine. The ileocecal junction is normally the boundary for lesions caused by SD. Lesions often begin as hyperemic and edematous mucosal lesions and progress to a mucosa covered by copious amounts of mucus and fibrin admixed with blood. These lesions often form a pseudomembrane. There also may be multifocal erosions of the surface mucosa, and ulcerative lesions are not generally seen.

One of the interesting things about swine dysentery is the rather underwhelming histologic lesion if your have been able to bear witness to the gross lesion, which has been described as a “bloody turkish towel” appearance to the mucosa. The histologic lesion often affects the superficial glands leading many pathologists to question whether the products of other bacteria may also be at pkay in fatal cases.
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New today in Noah from the AFIP Archive.

Tissue from a deer.

Morphologic diagnosis: Carotid artery: Numerous intraluminal filarid adults.

Name the agent: Elaeophora schneideri

Comment: Elaeophora schneideri is an interesting parasite whose natural host is mule and black-tailed deer. In the normal host, microfilariae are concentrated in cutaneous capillaries of the forehead and poll, and are ingetsed by horseflies, in which they mature to infective third stage larvae. When reinjected into a susceptible natural host, they migrate to the leptomeningeal arteries to mature and after two additional weeks, they migrate to their final home, the carotid arteries, where they live for 3-4 years.

In alternate hosts, such as sheep and elk, the adults remain in the small arteries of the head and face, resulting in thrombosis and a condition known as "sorehead" which may result in necrosis of the muzzle, ears, optic nerves, skin of the head and face, and horn deformitis. Blindness and death may also result. In the white-tailed deer, infection may be symptomatic; food impactions are a well-known sequela in this species
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