Six-year-old female French Alpine goat, (Capra aegagrus hircus).This goat was suspected to have aborted prior to necropsy, although no expelled fetus was found. This goat also aborted last year, but had successfully kidded in the past.

Gross Description:  

The uterine body contained two macerated fetuses with a crown to rump length of 16 cm and 10 cm. Within the uterus, all of the caruncles were enlarged (~4x2x1 cm), homogeneous, and pale tan.

Histopathologic Description:

The uterine caruncular labyrinth is diffusely expanded by abundant pale eosinophilic homogenous, extracellular material which is multifocally disrupted by areas of blue granular mineralization. The interdigitating cotyledonary villi are sparse, and the allantoic stroma is mildly expanded by edema.  The aforementioned interstitial eosinophilic material within the caruncles stains orange/pink with Congo red and exhibits apple green birefringence with polarized light, consistent with amyloid. The umbilicated surface of the placentome is multifocally ulcerated and replaced by large aggregates of neutrophils, lymphocytes, and histiocytes. Similar inflammatory cells extend into the subepithelial stroma of the caruncle, endometrium, and minimally throughout the labyrinth. The placental and endometrial stroma is expanded by moderate amounts of edema, few scattered inflammatory cells, and multifocal aggregates of mineral. There are also multifocal areas of mineralization throughout the tunica media of medium-sized vessels within the placenta and endometrium.

Morphologic Diagnosis:  

1. Uterus: Diffuse interstitial caruncular amyloid

2. Uterus and placenta: Chronic necrotizing placentitis and endometritis with mineralization

Lab Results:  

Bacterial culture and sensitivity (uterus):
Numerous Escherichia coli
Few Enterococcus faecalis
No growth of Brucella species
Chlamydophila sp , PCR (uterus): Negative
Coxiella burnetii, PCR (uterus): Negative


Bronchointerstitial pneumonia/Influenza virus

Contributor Comment:  

Caruncular amyloidosis has been previously reported in a small number of goats in California.  Clinical presentation of such goats included mid-to-late term abortion that often occurred repeatedly over multiple years which was attributed to impaired gas exchange at the site of fetal attachment.2 Ages ranged from 3-8, and breeds included Toggenburg, La Mancha, and Saan. Similar to the California goats, this goat had no evidence of amyloid deposition in other organs nor was there evidence of a systemic or chronic disease process.  Few bacteria were isolated from the inflamed region of the placentome but are considered to be secondary to the retained fetuses. Bacterial culture did not isolate Brucella abortus, and PCR was negative for Chlamidophila species and Coxiella burnetti.

In general, amyloid is composed of insoluble aggregates of misfolded proteins, and deposition of amyloid can occur in a wide variety of localized or systemic diseases.8  Although the fibrillar component of amyloid is overall similar in composition, a diverse number of proteins with variation in sequence and structure are considered amyloidogenic.7,8 Common amyloid precursors include: serum amyloid A (SAA), amyloid light chain (AL), islet amyloid polypeptide (IAPP), mutated forms of transthyretin, and beta protein amyloid.7,8

In particular, SAA proteins comprise a family of apolipoproteins that can be synthesized hepatically and/or extrahepatically. Hepatic derived SAA (SAA1 and SAA2) can dramatically increase in response to inflammation. In mice, rats, cows, and rabbits SAA3 appears to be the most common extrahepatic SAA in addition to being produced hepatically.3 Increased production of SAA3 has also been described in bovine and human mammary gland epithelium in response to prolactin, and in uterine papillary cancer. In the goats in California increased levels of SAA3 were detected within the endometrium when compared to the liver, suggesting localized expression. The type and cause of the amyloid deposition in this case is currently unknown, but the localized caruncular involvement is similar to what has been previously described and may represent a new syndrome of goats.2

JPC Diagnosis:  

Placenta, caruncle: Amyloidosis, diffuse, marked, French Alpine goat, Capra aegagrus hircus

Conference Comment:  

The contributor provides an informative summary of the pathogenesis of amyloidosis and review of previously reported cases of a unique syndrome of caruncular amyloidosis causing abortion in goats. This excellent case confounded conference participants on initial examination of the tissue section. Virtually every attendee interpreted the amorphous, smudgy, homogenous eosinophilic material that diffusely expands the uterine lattice as a geographic area of coagulative necrosis admixed with multifocal mineralization and mild inflammatory infiltrate in the subepithelial stroma of the caruncle and endometrium; collectively, the findings were attributed to normal post kidding involutional change, rather than caruncular amyloidosis. Similar to the findings reported by the contributor, Congo red histochemical staining of serial sections performed at the JPC demonstrates the eosinophilic proteinaceous material is diffusely congophilic and displays bright apple-green birefringence when viewed under polarized light.

Spirited discussion ensued among conference participants regarding the presence of concurrent diffuse necrosis, autolysis, or a combination of both admixed with the deposited amyloid in the tissue section. Most favored diffuse necrosis of both the epithelial and endothelial cells secondary to amyloid deposition, resulting in infarction of the placentome. Discord over the presence or absence of necrosis or autolysis nothwithstanding, this case nicely demonstrates a newly reported syndrome of reproductive failure in goats secondary to uterine amyloid deposition in the endometrium at the site of placental attachment.2 Accumulation of amyloid within the carucle markedly compromises blood flow and both gas and nutrient exchange between the doe and the fetus; this leads to fetal hypoxia and eventually death.2 Similar to previously reported cases of caruncular amyloidosis in goats2, amyloid is not present within the intercaruncular endometrium, myometrium, endometrial glands, or vessels in this doe.

Before discussing this case, participants reviewed the normal placentation in small ruminants. All ruminants have similar cotyledonary placentation composed of the fetal cotyledon and the maternal caruncle. The placenta contains the maternal endometrium and the fetal chorioallantoic membranes (CAM).1 Ruminant placentas are nondeciduate, indicating that the maternal endometrium and fetal CAM are in close contact, but they do not intimately fuse. In cotyledonary placentation, there are numerous areas where the fetal cotyledon villar attachments interdigitate with the crypts of the caruncular epithelium. The combination of the fetal cotyledon and maternal caruncle make up the placentome.1 In sheep and goats, the caruncles have a characteristic concave shape, nicely demonstrated in this case.1 Bovine placentomes are similar in structure and function, but are convex rather than concave.

Conference participants discussed various causes of abortion in small ruminants, to include infectious agents such as Chlamydophila abortus, Toxoplasma gondii, Brucella ovis, Campylobacter fetus, Coxiella burnetii, and Listeria monocytogenes. Non-infectious causes include plant toxins, such as locoweed poisoning, and nutritional factors including dietary deficiencies of copper, magnesium, vitamin A, and selenium.5,6 After reviewing this case, conference participants agreed that caruncular amyloidosis should be considered as an additional differential diagnosis of non-infectious abortion in the goat.


1. Bacha WJ, Bacha LM. Color Atlas of Veterinary Histology. 3rd ed. Baltimore, MD: Lippincott Williams & Wilkins; 2012:243-260.
2. Gaffney PM, Barr B, Rowe JD, Bett C, Drygiannakis I, Giannitti F, Trejo M, Ghassemian M, Martin P, Masliah E, Sigurdson C. Protein profiling of isolated uterine AA Amyloidosis causing fetal death in goats. FASEB J. 2015; 29:911-919.
3. Larson MA, Wei SH, Weber A, Weber AT, McDonald TL. Induction of human mammary associated serum amyloid A3 expression by prolactin or lipopolysaccharide. Biochem Biophys Res Commun. 2003; 301:1030–1037.
4. O’Brien TD, Butler PC, Westermark P, Johnson KH.  Islet amyloid polypeptide: A review of its biology and potential roles in the pathogenesis of diabetes mellitus. Vet Pathol. 1993; 30: 317-332.
5. Sanad YM, Jung K, Kashoma I, et al. Insights into potential pathogenesis mechanisms associated with Campylobacter jejuni-induced abortions in ewes. BMC Vet Res. 2014; 10:274-287.
6. Schlafer DH and Foster RA. Diseases of the gravid uterus, placenta and fetus In: Maxie MG, ed.  Jubb Kennedy and Palmer's Pathology of Domestic Animals. Vol 3. 6th ed. Philadelphia, PA:  Elsevier Saunders; 2016:407-408. 7. Tani Y, Uchida S, Nakamura H, Nakayama N, Goto D. Amyloid deposits in the gastrointestinal tract of aging dogs. Vet Pathol. 1997; 34:415-420.
8. Teoh SL, Griffin MD, Howlett GJ. Apolipoprotein and amyloid fibril formation in atherosclerosis. Protein Cell. 2011; 2(2):116-127.

Click the slide to view.

1.1 Uterus, goat.

1.2 Uterus, goat.

1.3 Placentome, goat.

1.4 Placentome, goat.

1.5 Placentome, goat.

1.6 Placentome, goat.

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