Amyloidosis in black-footed cats (Felis nigripes)

A high prevalence of systemic amyloidosis was documented in the black-footed cat (Felis nigripes) based on a retrospective review of necropsy tissues (n = 38) submitted as part of ongoing disease surveillance. Some degree of amyloid deposition was present in 33 of 38 (87%) of the examined cats, and amyloidosis was the most common cause of death (26/38, 68%). Amyloid deposition was most severe in the renal medullary interstitium (30/33, 91%) and glomeruli (21/33, 63%). Other common sites included the splenic follicular germinal centers (26/31, 84%), gastric lamina propria (9/23, 39%), and intestinal lamina propria (3/23, 13%). Amyloid in all sites stained with Congo red, and in 13 of 15 (87%) cats, deposits had strong immunoreactivity for canine AA protein by immunohistochemistry. There was no association with concurrent chronic inflammatory conditions (P = .51), suggesting that amyloidosis was not secondary to inflammation. Adrenal cortical hyperplasia, a morphologic indicator of stress that can predispose to amyloid deposition, was similarly not associated (P = .09) with amyloidosis. However, adrenals were not available from the majority of cats without amyloidosis; therefore, further analysis of this risk factor is warranted. Heritability estimation suggested that amyloidosis might be familial in this species. Additionally, tissues from a single free-ranging black-footed cat had small amounts of amyloid deposition, suggesting that there could be a predilection for amyloidosis in this species. Research to identify the protein sequence of serum amyloid A (SAA) in the black-footed cat is needed to further investigate the possibility of an amyloidogenic SAA in this species.     

Epidemiology of neoplasia in captive black-footed ferrets (Mustela nigripes), 1986-1996.

The epidemiology of neoplastic disease was studied retrospectively in the captive population of black-footed ferrets (Mustela nigripes). Postmortem reports were reviewed and archived tissues examined from 184 of the 227 adult (>1 yr old) black-footed ferrets that died from the beginning of the current captive propagation program in late 1985 to the end of 1996. A total of 185 neoplasms, of 28 distinct phenotypes, were seen in 102 (55.4%) of these ferrets. There was more than one tumor type present in 51 ferrets. Tumors of the apocrine glands (28.3%), renal tubular neoplasms (20.7%), and biliary cystadenoma or carcinoma (20.1%) were the most common neoplasms. The probability of developing most types of neoplasms increased with age. Neoplasms of the apocrine glands were more common in males and may be hormonally influenced. The unusually high prevalence of biliary cystadenocarcinoma may be secondary to the common occurrence of intrahepatic biliary cysts in this population. Although neoplasia is an important cause of mortality in captive adult black-footed ferrets, its impact on captive propagation of the species, and on the wild population, is probably limited because clinically significant tumors are encountered almost exclusively in postreproductive ferrets (>3 yr old) and because ferrets released into their natural habitat rarely reach susceptible age.     

Recombinant F1-V fusion protein protects black-footed ferrets (Mustela nigripes) against virulent Yersinia pestis infection.

Black-footed ferrets (Mustela nigripes) are highly susceptible to sylvatic plague, caused by the bacterium Yersinia pestis, and this disease has severely hampered efforts to restore ferrets to their historic range. A study was conducted to assess the efficacy of vaccination of black-footed ferrets against plague using a recombinant protein vaccine, designated F1-V, developed by personnel at the U.S. Army Medical Research Institute of Infectious Diseases. Seven postreproductive black-footed ferrets were immunized with the vaccine, followed by two booster immunizations on days 23 and 154; three control black-footed ferrets received a placebo. After the second immunization, antibody titers to both F1 and V antigen were found to be significantly higher in vaccinates than controls. On challenge with 7,800 colony-forming units of virulent plague by s.c. injection, the three control animals died within 3 days, but six of seven vaccinates survived with no ill effects. The seventh vaccinate died on day 8. These results indicate that black-footed ferrets can be immunized against plague induced by the s.c. route, similar to fleabite injection.     

Renal tubular-cell neoplasms in black-footed ferrets (Mustela nigripes)--38 cases

Thirty-eight cases of renal tubular cell neoplasms were diagnosed in 184 captive, adult (>1-year-old), black-footed ferrets (Mustela nigripes) examined from 1985 to 1996. This prevalence (20.7%) is one of the highest reported for this neoplasm in a population of animals. These tumors rarely metastasized (1/38), and usually were incidental postmortem findings, associated clinical disease being present in only 3 (8%) of the 38 cases. The prevalence of renal tubular cell neoplasms found at postmortem examination increased linearly with age, up to 67% in ferrets >8 years old. Both males (prevalence = 19%) and females (prevalence = 24%) were affected. Multiple renal tumors were common, and seven ferrets (18.4% of affected animals) had bilateral tumors. The cause of this neoplastic syndrome could not be determined. Since most of the animals affected by this condition were in their postreproductive years of life, the impact of this neoplastic syndrome on the captive propagation of this species is negligible.     

Comparative vaginal cytology of the estrous cycle of black-footed ferrets (Mustela nigripes), Siberian polecats (M. eversmanni), and domestic ferrets (M. putorius furo).

Vaginal cytology and vulva size were used to characterize the reproductive cycle of female black-footed ferrets (Mustela nigripes), Siberian polecats (M. eversmanni), and domestic ferrets (M. putorius furo). Emphasis was on black-footed ferrets because of the need to breed these critically endangered animals and on Siberian polecats because of the close taxonomic relationship to black-footed ferrets. Vaginal cytology of the 3 species of ferret is similar. Proestrus was characterized by an increasing percentage of superficial epithelial cells and enlargement of the vulva. During estrus, superficial cells were usually greater than or equal to 90% of epithelial cells in the vaginal lavage and after several days were fully keratinized. Neutrophils were more common during all stages of the estrous cycle in domestic ferrets than they were in the other species. Following copulation, percentage of superficial calls in the vagina declined and vulva swelling subsided. Large cells, probably of uterine symplasma origin, were observed in vaginal lavages following whelping or pseudopregnancy. Vaginal cytology is extremely useful in the reproductive management of black-footed ferrets and Siberian polecats. Knowledge of normal vaginal cytology could be applied to the diagnosis of female reproductive abnormalities in all 3 species.     

Renal amyloidosis in related English foxhounds

Renal amyloidosis was diagnosed in six related English foxhounds from two separate hunting kennels. There was no apparent age or sex predilection. All the dogs had clinical and laboratory findings compatible with renal disease. The onset of clinical signs was acute in all cases with death or euthanasia in five of the six affected dogs occurring within one week of presentation. The remaining dog was treated with diuresis which produced a temporary improvement. Histological examination of renal tissue from affected dogs identified the presence of both glomerular and interstitial amyloid, which was confirmed by immunohistochemical staining to be of the reactive type (amyloid A). There were occasional sclerosed glomeruli or glomeruli with thickened Bowman's capsules, in addition to interstitial and periglomerular infiltration with a predominance of plasma cells and lymphocytes and secondary changes including tubular eosinophilic casts. Renal papillary necrosis was identified in three dogs. One hound had concurrent multicentric lymphoma. Pedigree analysis of the affected dogs revealed that four individuals shared a common great grandsire and that the same dog was the grand-sire of a further case. Pedigree analysis of five additional dogs from one of the kennels, all of which had clinical signs of acute renal failure but from which renal tissue was not available, revealed a close relationship to those foxhounds with confirmed renal amyloidosis.     

Immunohistochemical identification of amyloid, using an anti-human serum amyloid P component (SAP) antibody, is possible in ruminants but not in dogs and cats

Amyloidosis represents a heterogenous group of diseases that have in common the deposition of fibrils composed of proteins of beta-pleated sheet structure, a structure which can be specifically identified by histochemistry using the Congo red or similar stains. Amyloid consists primarily of the amyloid fibrils but also of the amyloid P component (AP). This component, which is identical with the serum counterpart (SAP), is found in all types of human amyloid, and immunohistochemical identification of AP has been proposed as an adjunct to the universal, type-independent diagnosis of human amyloidosis. In the present study of animal amyloidosis, we compared the amyloid-specific Congo red stain with an immunohistochemical protocol using an anti-human SAP antibody for the identification of amyloid in formalin fixed tissue samples. The species and types of amyloidoses investigated were: (i) seven cows, one yak (Bos grunniens), and one sheep affected with amyloidosis of presumed AA type, (ii) one dog with a pancreatic endocrine tumour producing amyloid of presumed AIAPP type, (iii) two cats with presumed AIAPP-amyloidosis of the islets of Langerhans, one cat with presumed AA-amyloidosis, and one cat with an amyloid-producing odontogenic tumour. Intense immunostaining co-localized with amyloid, identified by its congophilia and green birefringence, using a protocol without any antigen retrieval in each of the seven cows, the yak and the sheep. The method seemed more sensitive in the ruminants than the Congo red stain, but was unable to detect amyloid in the dog and the cats regardless of the application of various antigen retrieval protocols. However, specific identification of amyloid still rests on the Congo red method or similar histochemical techniques.     

The Pathogenesis of Reactive Systemic Amyloidosis

The diagnosis of amyloidosis is based on the presence of extracellular tissue deposits of proteinaceous material that demonstrate a characteristic green color when stained with Congo red and viewed under polarized light. Several different proteins are amyloidogenic but, in domestic animals, spontaneously occurring systemic amyloidosis is reactive in nature and characterized by the presence of amyloid protein AA. This type of systemic amyloidosis may occur secondary to chronic inflammatory or neoplastic disease, but in many instances no predisposing disease is found. A sustained increase in the serum concentration of serum amyloid A protein (SAA) is necessary but not sufficient for the development of reactive amyloidosis. Other inherited and acquired host-related factors are likely to be important in the development of reactive amyloidosis because this condition develops in few patients with chronic inflammatory disease. The tissue tropism of amyloid deposits varies with the amyloid protein itself and species affected. The consequences of amyloidosis for the host depend upon the tissues involved and the response of these tissues to the presence of the amyloid deposits. In domestic animals, reactive systemic amyloidosis is nephropathic, leading to end-stage renal disease, and the clinical presentation is that of uremia.     

Renal amyloidosis in a family of beagles.

Renal amyloidosis was confirmed in 6 related male and female Beagles, ranging in age from 5 to 11 years. The most commonly reported signs of illness included lethargy, anorexia, vomiting, and weight loss. Common clinicopathologic abnormalities were normocytic, normochromic anemia; hypoalbuminemia; azotemia; hypercholesterolemia; proteinuria; and urine specific gravity values below the normal range. Histologic examination of renal tissue from the 6 Beagles revealed moderate to severe glomerular amyloidosis with inconsistently observed mild medullary interstitial amyloidosis. Congo red-stained kidney sections from 4 of 4 affected dogs were potassium permanganate-sensitive, suggestive of reactive amyloidosis. Hereditary predisposition for renal amyloidosis was suspected in these Beagles.     

Familial renal amyloidosis in Abyssinian cats

Medullary and glomerular amyloidosis, papillary necrosis, and secondary interstitial disease were diagnosed in eight related adult Abyssinian cats from two catteries. The lesions were similar to those in two unrelated mongrel cats with renal amyloidosis. Ultrastructurally, the patterns of amyloid deposition were as described in other species, although medullary deposition predominated. Potassium permanganate oxidation blocked Congo red staining of the deposits suggesting that they contained amyloid A protein (secondary amyloid). The disease may be a model of familial secondary amyloidosis and offers an opportunity to study the pathogenesis of both amyloid deposition and papillary necrosis. The histochemical characteristics of feline renal amyloid require careful attention to technique. Section thickness affects Congo red affinity and both dichroism as well as birefringence should be considered when interpreting staining reactions. Thioflavine-T may be the preferred stain for identification of small deposits of amyloid. Variation in section thickness markedly affected the degree of potassium permanganate oxidation.     

Systemic AA-amyloidosis in a European wild boar (Sus scrofa) suffering from generalized tuberculosis

Summary An adult female wild boar (Sus scrofa) was found moribund in Cabaneros National Park (central Spain). The animal had a markedly emaciated carcass, with body weight of 25.9 kg. At necropsy, most of the parenchymatous organs had widespread variably sized granulomas. Generalized tuberculosis was confirmed by PCR detection of Mycobacterium bovis in the mandibular lymph node. Large amounts of a hyaline, pale eosinophilic material were observed in liver, kidney and intestine. Congo red staining and green birefringence identified amyloid, which was further classified as AA type based on immunohistochemical results. It is speculated that the abundant serum amyloid A derivatives deposited in the tissues as AA-amyloid may be associated with the generalized tuberculosis. This is the first report of amyloidosis in the European wild boar.     

Renal amyloidosis in cattle with inflammatory diseases

BACKGROUND: The association of inflammatory diseases such as traumatic reticuloperitonitis (TRP), mastitis, metritis, and pododermatitis with renal amyloidosis in cattle is poorly described. HYPOTHESIS: Serum amyloid A (SAA) levels are elevated during inflammatory diseases, and renal amyloidosis is formed as a complication. ANIMALS: This study was conducted with 82 crossbred cattle with mastitis (n = 18 cows), metritis (n = 11 cows), TRP (n = 30 cows), and pododermatitis (n = 23 : 15 cows and 8 beef cattle). Ten clinically healthy cows served as controls. Methods: Hematological, urinary, and blood parameters, including SAA, were measured by an automated procedure provided with trade kits. Determination of amyloidal structures was made by histopathological examination of renal biopsy specimens. RESULTS: At the end of this trial, amyloidosis was detected in 5 cows displaying typical nephrotic syndrome, with hypoproteinemia and proteinuria in combination with polyuria and weight loss. Furthermore, it was observed that cows with renal amyloidosis had significantly higher (P < .01) total leukocyte counts, serum and urine enzyme activities, and urea and creatinine concentrations, with lower serum total protein concentrations, when compared with animals without renal amyloidosis. CONCLUSIONS AND CLINICAL IMPORTANCE: The incidence of AA amyloidosis in cattle in this study suggests that cattle with mastitis, metritis, and pododermatitis have a high prevalence of systemic amyloidosis in response to inflammation.     

Localized amyloidosis in canine mammary tumors

Histopathologic and immunohistochemical examinations were performed on localized amyloidosis associated with mammary tumors in two dogs. These tumors were identified as adenoma and adenocarcinoma. An acellular, amorphous pale eosinophilic material (amyloid) was observed in the lumina of acini lined by neoplastic cells and in the stroma of the tumors. Concentrically laminated pale eosinophilic bodies (corpora amylacea) were also found in the lumina of the acini. Amyloid and corpora amylacea stained positively with Congo red with and without 5% potassium permanganate pretreatment and revealed a green birefringence under polarized light. Corpora amylacea showed an occasional Maltese-cross pattern. Immunohistochemically, amyloid and corpora amylacea usually stained positively with anti-bovine alpha-casein antibody but negatively with anti-human amyloid AA, anti-bovine kappa-light and lambda-light chains, anti-human lactoferrin, anti-human transferrin, anti-human secretory component, and anti-human polyglucosan antibodies. These findings suggested that the amyloid deposition in these canine mammary tumors was related to lactating casein.     

Abdominal radiographic and ultrasonographic findings in ferrets (Mustela putorius furo) with systemic coronavirus infection

Ferret systemic coronavirus infection (FSCV) is a systemic disease in ferrets that clinically and pathologically resembles the dry form of FIP. The present study describes abdominal imaging features of 11 ferrets with FSCV. Abdominal survey radiographs were available for eight ferrets and ultrasound examination for all cases. Loss of lumbar musculature, decreased peritoneal detail, presence of mid-abdominal soft-tissue masses and splenomegaly were the most significant radiographic signs in these patients. Ultrasonographic findings including peritonitis, abdominal lymphadenopathy, splenomegaly, abdominal soft-tissue masses, nephromegaly and changes in the renal cortex echogenicity were recorded in the majority of cases with FSCV. As an imaging modality, ultrasound is superior to radiology when abdominal contrast is reduced, as it frequently occurs in these cases. However, although imaging techniques provide additional information in the antemortem diagnosis, they can not replace the definitive diagnosis based on histological and immunohistochemical results.     

Immunohistochemical identification of generalized AA-amyloidosis in a mountain gazelle (Gazella gazella)

Generalized amyloidosis was diagnosed post-mortem in a mountain gazelle (Gazella gazella). To test whether the amyloid deposits consisted of amyloid-A fibril protein a series of monoclonal and polyclonal antibodies directed against amyloid-A fibril protein of different species was applied to formalin-fixed paraffin sections using the indirect immunoperoxidase technique. The immunohistochemical results showed a moderate cross-reaction of gazelle amyloid with human, murine, hamster, and canine amyloid-A fibril protein. A strong cross-reaction, however, was found with one of two monoclonal anti-human amyloid-A antibodies and with an antiserum against bovine amyloid-A fibril protein, the amyloid fibril protein of another ungulate. These results demonstrate the presence of amyloid-A fibril protein in the gazelle amyloid and illustrate the diagnostic value of cross-reacting anti-amyloid-A antibodies for the identification of amyloid-A-amyloidosis in species and in individuals in which amyloid has not yet been examined.     

Prevalence of amyloid deposition in mature healthy chickens in the flock that previously had outbreaks of vaccine-associated amyloidosis

Avian amyloid A (AA) amyloidosis is commonly observed in adult birds with chronic inflammation, such as that caused by bacterial infection. We previously described vaccine-associated AA amyloidosis in juvenile chickens. In this study, the prevalence of amyloid deposition was measured in mature healthy chickens that survived a previous outbreak of avian AA amyloidosis while they were juveniles. Herein, we analyzed the amyloid deposition in mature chickens and compared the prevalence of amyloid deposition with juvenile chickens obtained in our previous study (Murakami et al., 2013). We found that: 1) amyloid deposition in the liver was absent in mature chickens, while juvenile chickens had a rate of 24%; 2) amyloid deposition in the spleen was observed in 36% of juvenile chickens and in 40% of mature chickens; 3) amyloid deposition in the pectoral muscle of mature chickens (43.75%) was approximately half that of juvenile chickens (88%). These results suggest that additional amyloid deposition in chickens previously exposed to AA amyloidosis may not worsen with age. Further, amyloid deposition in chickens may tend to regress when causative factors, such as vaccinations and/or chronic inflammation, are absent.     

乳牛肾淀粉样变病超微结构和免疫组织化学的研究

对临床尸检一例乳牛肾淀粉样变病进行了组织与超微病理学和免疫组织化学的研究。结果提示其淀粉样蛋白为无分枝、平行或非平行排列的微丝,主要沉积在肾小球和小血管周围。在肾小球,系膜区沉积最为严重,其次为肾小球毛细血管基膜。生物素-亲和素免疫过氧化物酶(ABC)染色结果显示,抗淀粉样蛋白A(AA)反应阳性颗粒沉积于肾小球和肾的小血管壁上,其抗AA阳性反应提示本病为继发性淀粉样肾病。     

Renal medullary amyloidosis in Dorcas gazelles

Between January 1976 and September 1987 renal medullary amyloidosis (RMA) was diagnosed in 17 Dorcas gazelles; the necropsy prevalence rate was 17/32 (53%). The most severe amyloid deposits were in the renal medulla; glomeruli were spared. Renal cortical lesions of interstitial fibrosis and tubular atrophy and dilatation significantly correlated with RMA (P less than 0.01) and were considered to be secondary changes. There were varying degrees of lymphoplasmacytic inflammation and tubular cast formation which did not significantly correlate with RMA. Amyloid was confirmed histochemically and by electron microscopy and was identified as AA type by the permanganate method. Progressive renal failure was the cause of death or necessitated euthanasia in 7/17 (41%) gazelles. RMA in Dorcas gazelles does not appear to be familial. A high prevalence of chronic or recurring Actinomyces (Corynebacterium) pyogenes infections may be an important factor.     

Familial renal amyloidosis in Chinese Shar Pei dogs

Renal amyloidosis was diagnosed in 14 young Chinese Shar Pei dogs, all of which were related. Clinical signs were those of renal failure and included vomiting, anorexia, lethargy, polydipsia, polyuria, weight loss, and dehydration. Some dogs had a history of intermittent fever and joint swelling. Laboratory findings also were compatible with renal failure and included azotemia, hyperphosphatemia, low total CO2 content in serum, isosthenuria, proteinuria, and hypercholesterolemia. All dogs had medullary deposition of amyloid, and 9 of 14 (64%) had glomerular involvement. The remaining renal lesions were typical of end-stage renal disease. In some dogs, amyloid deposits were found in other tissues (eg, liver, spleen, stomach, small intestine, myocardium, lymph node, prostate gland, thyroid gland, and pancreas). Amyloid deposits were sensitive to potassium permanganate oxidation, suggesting the presence of amyloid protein AA.