Generalized amyloidosis in rhesus monkeys

Necropsy materials from 57 cases of generalized amyloidosis in rhesus monkeys were reviewed. Clinically, animals with the disease were characterized by cachexia with muscle wasting, recurrent diarrhea, and arthritis. Gross lesions included hepatomegaly, splenomegaly, chronic/active colitis, fibrous strictures of the cecocolic junction, osteoarthritis, and generalized muscle atrophy. Histologic examination revealed minimal to severe deposits of amyloid in the small intestine (100%), spleen (93%), large intestine (67%), liver (40%), lymph nodes (71%), stomach and/or adrenal gland (32%). More amyloid was deposited in the spleen, liver, and small intestine than in other organs. Shigella sp. were isolated from feces in 23% of the cases and 84% had histologic evidence of colitis. Other findings indicated that 100% of the animals had lung mites, 25% had strictures of the cecocolic junction, and 40% had osteoarthritis. Thirty percent of the cases occurred in animals 10 months to 5 years of age, 10% in ages 6 to 10 years, and 60% in animals greater than 10 years old.     

Pathological lesions in swine at slaughter. II. Culled sows

The same computerized recording system as described in Part I of this publication (Flesjå & Ulvesœter 1979) was applied to sows slaughtered at Sentralslakteriet, Forus, Stavanger.In the three-year period 1975–1977 a total of 10,051 apparently healthy sows were brought to the abattoir. About 17 % of the carcasses had one or more pathological lesions. Of the total number of lesions 89 % were confined to 18 of the available 57 disease codes. Pyaemia and abscess/-es occurred at a rate of 1.5 and 3.2 %, respectively. This comprised 21 % of all registered lesions. Scabies and numerous white liver spots came to another 21 %, occurring in 3.3 and 1.5 % of the animals, respectively. About 15 % were chest lesions, of which pleurisy was diagnosed in 1.4 % and pericarditis in 1.3 % of the slaughtered sows. Other lesions recorded in 1 % or more included perihepatitis and other non-parasitic liver lesions, arthritis and decubitus.Only code 31 — numerous white spots in the liver showed a convincing seasonal variation.Significantly higher frequencies of pyaemia and abscess/-es occurred in culled sows than in baconers, but no such difference could be found for peritonitis, polyarthritis and arthritis. For all other commonly observed lesions significantly lower frequencies were seen in sows compared to baconers.Various theories are suggested to explain the observed difference in the distribution of lesions between baconers and sows.     

Disseminated oesophagostomiasis in the rhesus monkey.

Disseminated oesophagostomiasis was diagnosed at necropsy of 5 rhesus monkeys (Macaca mulatta). Nodular lesions were in visceral organs as well as in the colon and mesentery. Lesions varied greatly with respect to degree of organ involvement and damage due to parasite invasion. In 2 monkeys, nodular lesions were in the colon, mesentery, liver, kidneys, abdominal wall, urinary bladder, and uterus; in 1 of these 2 monkeys, a nodular lesion inhabited by a parasite was in a lung. The ectopic nodules in the less severely affected monkeys were scattered in the liver, kidneys, and abdominal wall.     

CELLULAR FEATURES OF SONOGRAPHIC TARGET LESIONS OF THE LIVER AND SPLEEN IN 21 DOGS AND A CAT

Target lesions are seen in ultrasound images of the liver or spleen as nodules or masses with a hypoechoic rim and a hyperechoic or isoechoic center. To assess the diagnostic significance of finding a target lesion, the cytologic and/or histopathologic findings were reviewed in a series of 21 dogs and a cat that had hepatic and/or splenic target lesions noted during abdominal ultrasonography. Twelve of 16 hepatic target lesions and 5 of 7 splenic target lesions were malignant. In this series, the finding of one or more target lesions in the liver or spleen had a positive predictive value for malignancy of 74%; for the finding of multiple target lesions in one organ, the positive predictive value for malignancy was 81%. Benign lesions associated with target lesions were nodular hyperplasia of the liver and spleen, pyogranulomatous hepatitis, cirrhosis, and chronic active hepatitis.     

Multisystemic abscesses in African green monkeys (Chlorocebus aethiops) with invasive Klebsiella pneumoniae--identification of the hypermucoviscosity phenotype

Invasive Klebsiella pneumoniae is an emerging disease of humans characterized by abscesses in the liver or other sites involving bacteria with the unique hypermucoviscosity phenotype. Over several months, 7 African green monkeys in our research colony developed abscess formation in multiple locations and succumbed to disease. K. pneumoniae was identified by bacterial culture in 6 monkeys and immunohistochemistry in 1 additional monkey. All monkeys had been housed in, or had contact with monkeys housed in, 1 animal room in our facility. All affected monkeys had 1 or more abscesses, most notably in the abdomen, but also affecting the lungs, cerebellum, and skin. Abdominal abscesses and associated adhesions entrapped loops of bowel, forming palpable masses. Abdominal masses were located at the root of the mesentery, the ileocecocolic junction, or the pelvic inlet. In 1 case, culture, serotyping, and polymerase chain reaction (PCR) analysis of the bacterial isolate identified K. pneumoniae expressing the hypermucoviscosity phenotype and capsular serotype K2 and determined that the K. pneumonia was genetically rmpA(+)/magA(-).     

The pathology and aetiology of lung lesions in goats infected with caprine arthritis-encephalitis virus

Fifty dairy goats, of various ages, sexes and breeds were selected for examination on the basis of positive serological reactions to caprine arthritis-encephalitis virus (CAEV). Thirty-one had lung lesions including chronic interstitial pneumonia of caudal or cranioventral lobes, bronchopneumonia, verminous pneumonia, pulmonary cryptococcosis or combinations of these. The only infective agent recovered from all the chronic interstitial pneumonia cases examined was CAEV, which was also recovered from lung tissue of 3 goats with arthritis but no lung lesions. The presence of CAEV in lavaged alveolar macrophages from normal lung tissue and from lungs affected with chronic interstitial pneumonia and verminous pneumonia, and the demonstration of a marked increase in nonspecific esterase staining macrophages in areas of chronic interstitial pneumonia, are discussed in relation to the aetiology of the pneumonia.     

Pathologic findings in rabies-suspect, random-source, and accidentally killed skunks

To evaluate sampling biases, pathologic findings in accidentally killed skunks (ie, killed by motor vehicles) were compared with those in random-source skunks (live-trapped and euthanatized, or trap-killed during research) and skunks submitted to a public health laboratory as rabies-suspect. Presence or absence of microscopic lesions in the brain, kidneys, liver, and lungs were used to test the null hypothesis that prevalence of disease did not differ by source of collection. Brain lesions differed with the source; rabid and nonrabid skunks submitted to a public health laboratory had higher prevalences of lesions than did other skunks. Kidney, liver, and lung lesions did not differ among skunks by source of collection. Liver and lung lesions were attributed mainly to parasitism, were not severe, and did not cause debilitated condition. Lesions were seen more often in the kidneys than in other tissues. Usually, lesions were mild to severe, focal, chronic, nonsuppurative, interstitial nephritis (possibly a consequence of leptospirosis). Six of 177 skunks necropsied appeared cachectic. Aleutian disease was diagnosed in one skunk and histoplasmosis was diagnosed in another, but rabies and canine distemper virus infection were the only diseases found with the potential to cause the high population mortality. Public health surveillance cases were biased toward diseased animals (rabies and canine distemper virus infection), but random-source or accidentally killed animals provided unbiased data. Although other factors must be considered, accidentally killed skunks provided cost-effective and useful data for the evaluation of enzootic rabies.     

Lentivirus-induced pulmonary lesions in rhesus monkeys (Macaca mulatta) infected with simian immunodeficiency virus.

Necropsy reports from 28 rhesus monkeys that had been experimentally infected with simian immunodeficiency virus (SIV) and that were free of cytomegalovirus were reviewed. Lung sections from 24 of these monkeys that had no etiologic agent other than SIV detected in the lung were studied in detail by histopathologic, immunohistochemical, and electron microscopic examination and by in situ hybridization. Fourteen of the monkeys were part of a serial euthanasia study, while others were euthanatized after they became moribund. The following lesions were detected: perivascular inflammation, vasculitis, interstitial pneumonia, syncytial cells, hemorrhage, fibrin exudation, and pleural fibrosis. Perivascular inflammation was the most frequent lesion and occurred as early as 2 weeks after inoculation. Severe pneumonia and numerous syncytial cells were seen only in animals euthanatized because they had become moribund. The lesions appeared to be directly due to SIV infection. SIV antigens, RNA, and virions were detected in syncytial cells and macrophages by immunohistochemical examination, in situ hybridization, and transmission electron microscopic examination, respectively. The amount of virus present was correlated with the severity of the lesions. The SIV-induced lesions were different from those of the lymphocytic interstitial pneumonia, which occurs in human immunodeficiency virus-infected children and in ovine lentivirus-infected sheep and goats.     

Hydatid echinococcosis (Echinococcus granulosus) in a laboratory colony of pig-tailed macaques (Macaca nemestrina)

Several cases of hydatid echinococcosis were diagnosed in a laboratory colony of 19 pig-tailed macaques (Macaca nemestrina) at the Paul Ehrlich Institute, Germany. Three hydatid cysts were found in the liver of an euthanized animal. The diagnosis of an Echinococcus granulosus infection was confirmed by histopathology and the results of a specific polymerase chain reaction. The serum of five of 14 other monkeys tested for Echinococcus antibodies using a genus-specific enzyme-linked immunosorbent assay (ELISA) was positive or weakly positive; none of the animals, however, showed specific reactions in a E. multilocularis-specific ELISA. On ultrasonographic examination, alterations in the liver were found in four of the serologically positive monkeys, and two animals showed clinical signs such as progressive anorexia, apathy and icterus. The monkeys had most probably acquired the E. granulosus infection in their breeding colony in Slovenia.     

Experimental Brucella canis Infection in the Monkey (Macaca arctoides)

Four stumptail Macaque monkeys (Macaca arctoides) were each inoculated with approximately 10¹⁰ organisms from a culture of Brucella canis. Two animals were inoculated via the oral and conjunctival route and the other two monkeys were inoculated intravenously with the organisms. A fifth animal served as a control. Blood samples were taken at weekly intervals for hematological, serological and bacterialogical studies. The monkeys were killed at five and ten weeks post-inoculation and tissues taken from a variety of organs for bacterial culture. B. canis was isolated from the peripheral blood of inoculated monkeys for up to seven weeks post inoculation and all infected monkeys developed significant neutralizing antibody titers to the organism. The bacterium was isolated from some tissues, including the uterus of one monkey, in the two animals killed at five weeks post-inoculation. Focal granulomatous lesions were sometimes observed in the liver, spleen and lymphoid tissue of inoculated monkeys. Such lesions are similar to those described in other brucella infections. Human infections with B. canis have occurred and the possible dangers entailed in exposure to the organism should again be emphasized.     

Detection of Echinococcus multilocularis infection in a colony of cynomolgus monkeys (Macaca fascicularis) using serology and ultrasonography.

Five animals in a colony of cynomolgus monkeys (Macaca fascicularis) died or were euthanatized because of alveolar echinococcosis, during a period of 5 years. The remainder of the colony was screened for possible infection with Echinococcus multilocularis, using serology and ultrasonography. A total of 46 animals out of a group of 55 were examined. The presence of anti-Em2 antibodies analyzed with enzyme-linked immunosorbent assay was demonstrated in 3 monkeys. In 2 of these 3 monkeys, multilocular structures compatible with metacestodal cysts in the liver were identified, using ultrasonography. The presence of alveolar echinococcosis was subsequently confirmed at postmortem examination in 1 animal. The other animals are still alive. Two other monkeys were negative in the serological examination but had cystic structures in the liver, which were identified as bile duct cysts at postmortem examination in 1 animal. The other monkey is still alive. These findings suggest that serology for antibodies against the Em2 antigen may represent a useful method in identifying animals that might be infected with E. multilocularis and are therefore at risk of developing fatal alveolar echinococcosis.     

Pathological Lesions in Swine at Slaughter: I. Baconers

An extended disease recording programme in pigs has been carried out by the meat inspection service at Sentralslakteriet, Forus, Stavanger. A data system including 57 disease codes has been applied. In the period 1975–1977 an average of 85,000 baconers were slaughtered yearly. About 39 % of these were given disease remarks; 42–47 % of the lesions were directly related to the parasites Sarcoptes scabiei (rind lesions) and Ascaris suum (white spots in the livers). The thoracic cavity was the most commonly affected part of the body with 30–35 % of all recorded lesions.Sixteen disease codes occurred at frequencies above 0.3 %, and they encompassed approx. 97 % of all recorded lesions. Scabies occurred at an average of 12 % of the fatteners. Parasitic hepatitis of severe and moderate degrees were seen in about 11 %, pleurisy in 7 %, pneumonia — severe and moderate — in 5.4 %, pericarditis in 4.3 %, pyaemia and abscess/-es in 2.5 %, tail lesions in 2.3 %, perihepatitis and other non-parasitic liver lesions in 2.2 %, polyarthritis and arthritis in 1.7 %, tuberculous lesions in the cervical lymph nodes in 0.9 %, peritonitis in 0.9 % and atrophic rhinitis — external lesions — in 0.8 % of the carcasses. The majority of the other 41 disease codes occurred at frequencies below 0.1 %.A seasonal variation was pronounced in scabies, numerous white spots in the liver, and tuberculous lesions in the cervical lymph nodes. It could be noted in pleurisy, pericarditis, perihepatitis and other non-parasitic liver lesions, arthritis and atrophic rhinitis, but not in pneumonias, moderate number of white spots in the liver, tail lesions, pyaemia, abscess/-es, peritonitis and polyarthritis.     

Morphologic changes following intraarticular inoculation of Mycoplasma bovis in calves

Intraarticular inoculation of Mycoplasma bovis into the joints of six-week-old calves caused severe arthritis in five inoculates and mild arthritis in a sixth. Intraarticular inoculation of killed M. bovis did not cause arthritis. Arthritic calves had fever, joint swelling, lameness, neutrophilia, and intercurrent pneumonia from which M. bovis could not be recovered. Gross lesions were massive fibrinosuppurative synovitis and tenosynovitis, erosion of cartilage, and its replacement by polypoid granulation tissue. Histologic lesions were extensive ulceration of synovial membranes, leukocytic infiltration of the subsynovium, congestion, hyperemia, and thrombosis of the subsynovial vessels. Cartilage erosion was accompanied by chronic osteomyelitis and formation of pannus tissue. The presence of thrombi and platelet aggregates suggests that the inflammatory process in the synovium may arise from the interaction of M. bovis with the vasculature and the coagulation process of the host.     

Necropsy findings in rhesus monkeys experimentally infected with cultured simian immunodeficiency virus (SIV)/delta

Lesions induced in rhesus monkeys by different isolates of simian immunodeficiency virus (SIV)/Delta were studied at necropsy. Four groups of monkeys were inoculated with SIV/Delta isolated from other experimentally infected rhesus monkeys, while one group was inoculated with SIV/Delta from an asymptomatic mangabey monkey. Three rhesus isolates and the mangabey isolate were virulent, killing 75-100% of infected monkeys. One rhesus isolate, which had been extensively passaged in vitro, was attenuated but was restored to virulence by single animal passage. Clinically, infected monkeys had lymphadenopathy, splenomegaly, diarrhea, and a rash. Most monkeys died of enteric disease. The following lesions were seen: weight loss, thymic atrophy, lymphoid atrophy, bone marrow hyperplasia, encephalitis, colitis, amyloidosis, hepatitis, glomerulosclerosis, and the presence of syncytial cells. One Rh Epstein-Barr virus (EBV)-related lymphoma occurred. Opportunistic agents were identified: cytomegalovirus, adenovirus, Cryptosporidia, and Pneumocystis. Shigella and Campylobacter often caused colitis.     

Hepatic alveolar echinococcosis in cynomolgus monkeys (Macaca fascicularis)

Alveolar echinococcosis was diagnosed in 12 cynomolgus monkeys (Macaca fascicularis) at postmortem examination within a period of 6 years. Besides consistent involvement of the liver, parasitic lesions were also present in mesenteric lymph nodes, pancreas, lung, and kidney. In the liver, various patterns of host's responses to parasitic tissue could be distinguished. Infiltration of macrophages, often multinucleated, around usually intact metacestodes was the main feature of one pattern. A second pattern was characterized by the presence of abundant, normally degenerate granulocytes in addition to macrophages surrounding collapsed laminated structures. Finally and as a third pattern, some cysts were surrounded by marked collagen deposition, which was usually not a significant feature of the other foci. Parasitic cysts with protoscolices were observed in foci with the first and third pattern but not in the second one. The simultaneous occurrence of all three patterns was observed in most animals. Type AA amyloid was identified either in the space of Dissé, macrophages or blood vessel walls in nine animals using immunohistochemistry. Identity of parasitic structures such as metacestodes of Echinococcus multilocularis was confirmed immunohistochemically. All animals that could be tested serologically (7/12) had detectable antibodies against the E. multilocularis-specific Em2 antigen. Liver lesions of six animals were additionally analyzed by polymerase chain reaction, yielding the amplification of a specific E. multilocularis DNA fragment in each case.     

Noninfectious canine arthritis: the inflammatory, nonerosive arthritides.

Noninfectious, nonerosive arthritis was seen as an important manifestation of a number of chronic systemic diseases of the dog. Sixty-three dogs with this type of arthritis were seen at the Veterinary Medical Teaching Hospital during an 18-month period between 1973 and 1975. Of these dogs, 29 had systemic lupus erythematosus, 15 had arthritis in association with some chronic infectious disease process, and 19 had a similar type of arthritis, but without serologic evidence of systemic lupus erythematosus or any chronic infectious disease process.     

Hydatid Echinococcosis (Echinococcus granulosus) in a Laboratory Colony of Pig‐Tailed Macaques (Macaca nemestrina)

Several cases of hydatid echinococcosis were diagnosed in a laboratory colony of 19 pig‐tailed macaques (Macaca nemestrina) at the Paul Ehrlich Institute, Germany. Three hydatid cysts were found in the liver of an euthanized animal. The diagnosis of an Echinococcus granulosus infection was confirmed by histopathology and the results of a specific polymerase chain reaction. The serum of five of 14 other monkeys tested for Echinococcus antibodies using a genus‐specific enzyme‐linked immunosorbent assay (ELISA) was positive or weakly positive; none of the animals, however, showed specific reactions in an E. multilocularis‐specific ELISA. On ultrasonographic examination, alterations in the liver were found in four of the serologically positive monkeys, and two animals showed clinical signs such as progressive anorexia, apathy and icterus. The monkeys had most probably acquired the E. granulosus infection in their breeding colony in Slovenia.     

Physiologic manifestations of stress from capture and restraint of free-ranging male African green monkeys (Cercopithecus aethiops).

Adrenal gland weights, stomach mucosal lesions, and morning serum cortisol and prolactin levels were measured in 15 juvenile and adult male African green monkeys (Cercopithecus aethiops) that were shot by a hunter, euthanized after 24 hr of captivity, or euthanized after 45 days of captivity and intermittent blood sampling. Hormone levels were measured in seven additional males that had been in captivity for 7 mo. Mean serum cortisol concentrations were significantly lower in free-ranging wild monkeys at the time they were shot than in the monkeys after 1 day in captivity. Cortisol concentrations were significantly higher in wild-caught monkeys on the day after capture than they were in the same animals after 18 and 26 days of captivity. Cortisol concentrations were also significantly higher in the wild-caught monkeys 18 days after capture than in the laboratory-habituated monkeys in captivity for 7 mo. Mean prolactin concentration was significantly lower in the wild-caught monkeys on day 2 after capture, and the levels increased gradually to 45 days in captivity and was highest in monkeys that had been captive for 7 mo.     

MAGNETIC RESONANCE IMAGING IN FOALS WITH INFECTIOUS ARTHRITIS

The magnetic resonance (MR) imaging findings of foals with infectious and noninfectious arthritis are described. Six foals with infectious arthritis and three foals with noninfectious arthritis were grouped based on synovial fluid analysis results and examined with radiography and MR imaging. Four out of six foals with infectious arthritis had osseous lesions in MR images indicative of osteomyelitis and only 4/19 lesions were detected on digital radiographs. The three foals with noninfectious arthritis had no osseous lesions in MR images or radiographically. Of the six joints that had osseous lesions detected with MR imaging, three had at least one lytic lesion detected radiographically. Osseous lesions in the epiphysis, metaphysis, and physis appeared in MR images as T2W, short tau inversion recovery, and proton density hyperintense foci with a hypointense halo. The same lesions appeared hyperintense in the 3D RSSG water excitation pulse sequence but lacked a surrounding hypointense halo. Most joints of foals with infectious arthritis had heterogenous signals within the synovial fluid whereas all of the nonseptic joints had homogenous synovial fluid signals. MR imaging appears to be better than radiography in the detection of osseous lesions in foals diagnosed with infectious arthritis and may be a valuable screening test for the presence of osteomyelitis.     

Studies of encephalitozoonosis in vervet monkeys (Cercopithecus pygerythrus) orally inoculated with spores of Encephalitozoon cuniculi isolated from dogs (Canis familiaris)

Encephlitozoonosis was induced in 35 of 38 vervet monkeys (Cercopithecus pygerythrus). They were either directly (orally) inoculated with Encephlitozoon cuniculi or indirectly exposed to this protozoan parasite. Cell-culture-grown spores of E. cuniculi, isolated from the kidneys of dogs with natural, fatal disease, were administered orally to 29 of these monkeys. Another 5 were exposed in utero by orally infecting pregnant females, and 3 were exposed to horizontal infection by nursing infected infants. Only one was given an intravenous inoculation of spores. The disease was induced in non-gravid and late-pregnant adults, immunocompetent infants, and in infants that were immunologically compromised by parenteral steroid administration, as well as in one infant that was immunologically immature because of its premature birth. The effects of age, dosage, post-inoculation (PI) interval, passage level of the parasite in cell culture and immunological status of the host were correlated with macroscopical and microscopical lesions. The experimentally induced infection was confirmed either by reisolation of the parasite in cell culture or by observation of spores in tissue sections. Both confirmatory methods were supported by serological examination. Reisolation of the organism in primary cell culture prepared from kidneys usually resulted in more frequent isolates and larger yields of spores from infants than from adult vervets. Infection with E. cuniculi invariably induced subclinical disease. Based on histology, lesions were minimal to moderately severe, depending on age, PI interval, and immunological status of the host. Alimentary tract infections were seen histologically as early as three days PI. Subsequently, infections resulted in detectable lesions most consistently in the liver, kidneys and brain. Lesions in these organs were generally granulomatous and were similar to those found in canine encephalitozoonosis. In addition, multifocal interstitial pneumonitis and myocarditis as well as vasculitis and perivasculitis were seen in other tissues and organs. Infants had more severe and more widespread lesions than adults. Although lesions and spores were still present in the brain of one immunocompetent infant 36 weeks after initial infection, the disease in immunocompetent infants and adults is thought to be self-limiting. However, infection may persist. Immunological depression favoured increased growth and multiplication of the organism, and resulted in detection of more spores within inflammatory lesions as well as more intracellular colonies of the organism that were free of inflammatory reaction.(ABSTRACT TRUNCATED AT 400 WORDS)