Fatal hepatic sarcocystosis in a puppy with eosinophilia and eosinophilic peritoneal effusion

A 3-month-old male Golden Retriever puppy was evaluated for lethargy and fever of 2-days duration. Results of a CBC and biochemical profile revealed marked eosinophilia (6.3 X 10(3)/microL; reference interval 0.1-1.2 X 10(3)/microL), moderate thrombocytopenia, and increased activities of alanine aminotransferase, aspartate aminotransferase, and creatine kinase. Hepatomegaly and peritoneal effusion were found using abdominal ultrasound. Peritoneal fluid analysis revealed eosinophilic inflammation (23,000 nucleated cells/microL with 88% eosinophils). Despite supportive treatment the puppy's condition deteriorated rapidly; euthanasia was requested, and a necropsy performed. Microscopically, there was marked necrosuppurative and eosinophilic hepatitis with vasculitis. Numerous hepatocytes contained protozoal organisms suspected to be Toxoplasma gondii or Neospora caninum. However, serum was negative for both T gondii and N caninum antibodies; polymerase chain reaction assay on hepatic tissue was negative for both organisms; and immunohistochemical evaluation of hepatic tissue using serum raised against T gondii, N caninum, and Sarcocystis neurona also was negative. Schizont morphology suggested that merozoites replicated by endopolygeny, forming rosettes around a central residual body. Transmission electron microscopy revealed that merozoites lacked rhoptries. These findings were consistent with a diagnosis of Sarcocystis canis, an apicomplexan parasite with an unknown life cycle.     

An outbreak of sarcocystosis in a cattle herd.

In a cattle herd, 3 steers had anorexia and variable emaciation; 1 showed additional muscle stiffness, pyrexia, became recumbent and was killed in extremis. Gross changes in tissue specimens from this steer included grey-white foci in the skeletal muscle and a thickened, fibrous pleura. By histology interstitial pneumonia, myocarditis and necrotizing myositis were seen. There were wide-spread vascular lesions with endothelial damage, thrombosis and periarterial infiltrations. Sarcocystis-like schizonts were found in several organs, and different stages of thin-walled sarcocysts were seen in the myocardium. Examination of organs of 6 other steers in the same herd slaughtered 2 months later showed myocarditis, myositis, interstitial pneumonia and occasional vascular occlusions. There were a few schizonts in the spleen and lungs, and thin-walled sarcocysts were seen in the myocardium and skeletal muscle. It is concluded that development of vascular lesions probably represents an important step in the pathogenesis of sarcocystosis.     

Encephalitic sarcocystosis in a newborn calf

Sporozoan schizonts were seen in histologic sections of cerebrum from a Hereford calf that died immediately after birth. Schizonts appeared in endothelial cells of small vessels in the gray and white matter. Rosette and palisade configurations of merozoites in schizonts, as well as the size of schizonts (15 to 40 X 21 microns) and merozoites (8 microns), resembled Sarcocystis stages described in cattle, and differentiated the organisms from Toxoplasma that infects nerve cells and undergoes endodyogeny. Specific identification of the infecting agent was not successful because tests of sera from the calf were not possible. Developmental, morphologic, and ultrastructural differences in schizogonic stages of the heteroxenous sporozoan species infecting cattle are poorly known and are presently unreliable criteria for species identification. Encephalitis, meningitis, and necrosis occurred in cerebral, cerebellar, and brain stem gray and white matter infiltrated with plasmacytes, lymphocytes, and macrophages. Microthrombi were often seen in small blood vessels within the reaction foci. Herd-mate sera tested against S cruzi were negative. The herd from which the calf was born was exposed to a variety of free-ranging domestic, feral, and wild scavengers with free access to dead range animals. Consequently, the cattle were undoubtedly exposed to infective cysts in feed or water contaminated by feces from carnivores.     

Pulmonary sarcocystosis in a puppy with canine distemper in Costa Rica.

Canine distemper and pulmonary sarcocystosis were diagnosed in a 10-week-old Rottweiler with 4-day history of diarrhea, vomiting, and weakness. Microscopic examination of the lung revealed bronchointerstitial pneumonia typical of morbillivirus infection. Also, numerous apicomplexan parasites were scattered in the alveolar walls. This protozoan infection was first thought to be toxoplasmosis but immunoperoxidase staining revealed large numbers of Sarcocystis canis. This is the first case of canine sarcocystosis reported from Latin America that further emphasizes the importance of immunohistochemistry in the differential diagnoses of apicomplexan infections in dogs.     

Disseminated sarcocystosis in a cat with lymphosarcoma

Cysts of the protozoan Sarcocystis sp were found in skeletal and cardiac musculature in a 1.5-year-old cat with lymphosarcoma. The cat was FeLV-positive and had grossly visible neoplastic involvement of the spinal cord, mediastinum, bone marrow, and kidneys. Ultrastructural examination of the parasitic cyst wall suggested that the species in this case was different from that described in the only other reported case. It was hypothesized that immunosuppression from FeLV infection permitted an aberrant life cycle with encystment of Sarcocystis sp in this cat.     

Neurological symptoms associated with sarcocystosis in adult sheep.

Four mature ewes developed mild neurological symptoms. Histological examination revealed a nonsuppurative encephalitis and myelitis associated with protozoan cysts identified as Sarcocystis spp. by immunoperoxidase. The mild clinical signs and apparent recovery of 1 ewe suggest that neurological disease caused by Sarcocystis spp. may be more common than indicated by the infrequency of reports.     

Neosporosis, toxoplasmosis, and sarcocystosis in ruminants.

Neospora caninum, Sarcocystis spp, and Toxoplasma gondii are related coccidian parasites that can cause abortion and neonatal mortality in animals. In addition, T gondii and certain species of Sarcocystis are zoonotic. This article reviews information on the etiology, diagnosis, control, and prevention of these diseases.     

Acute hepatic failure

Acute hepatic failure is characterized by a sudden catastrophic compromise of hepatic failure that causes clinical signs such as anorexia, depression, vomiting, diarrhea, icterus, and encephalopathy. Injurious hepatotoxins, drugs, infectious agents, or metabolic disturbances can cause acute hepatic failure; however, in many cases, the inciting cause is not determined. Treatment is aimed at controlling complications such as fluid-electrolyte imbalances, hepatic encephalopathy, hypoglycemia, bleeding diathesis, gastric ulcer, sepsis, and endotoxemia, in order to provide time for liver regeneration and recovery.     

山羊肉孢子虫病的诊治

湖南省株州县淦田镇某殖户2005年7月从山东购进的50只波尔种山羊。5天后发病，厌食发热、贫血、急剧消瘦，经抗菌素等药治疗无效，陆续死亡10只，后经病理解剖，实验室检查诊断为肉孢子虫病，经用腹方磺胺间甲氧嘧啶0．1g-0．05g/kg治疗，每天肌注1次，连续5天，获愈。     

Development of sarcocystosis in experimentally infected calves

In seven calves we studied experimental invasions by sporocysts of the Sarcocystis cruzi (S. bovicanis) species, isolated from faeces of dingo dogs. Out of clinical changes, an increase in body temperature to 39.6 to 40.5 degrees C is characteristic in the fourth to the eighth week of disease, relaxed attitude of animals, progressive thinning down, anaemia of mucous membranes, diarrhoea and total dehydration. The post-mortem examination completes this observation with generalized hyperplasia of lymphatic nodes to haemorrhagic lymphadenitis and small petechial haematomata on serous coats, particularly on epicardium. Schizonts in the endothelium of capillaries in various organs were evaluated as specific lesions, demonstrated within 26 days from invasion in one calf. From 46 days after invasion we found muscular cysts in three other calves. The titres of sera in all experimental calves obtained with the NFR method are also evaluated as specific. Invaded calves died gradually between the 26th and 59th day, control calves were slaughtered and no sarcocysts were found.     

Taenia coenurus in the orbit of a chinchilla

A 4-year old, male intact, captive-bred chinchilla (Chinchilla lanigera) was presented due to progressive exophthalmos of the right eye over a 5-month period. Ophthalmic examination revealed exophthalmos with dorsal displacement of the right globe. Retropulsion was decreased and a fluctuant, subcutaneous mass could be palpated posterior and dorsal to the central aspect of the zygomatic bone. Transdermal ultrasonography revealed a fluid-filled mass consistent with a cyst located within the ventral right orbit. Computed tomography demonstrated dorsal displacement of the globe, lateral displacement of the zygomatic arch, and numerous mineral-dense foci within the lumen of the cyst. The cyst was removed en bloc by ventral transpalpebral orbitotomy. Histopathology revealed a single capsulated cyst with multiple invaginated protoscolices, characterized by a prominent scolex with refractile hooklets, suckers, and abundant calcareous corpuscles consistent with a Taenia coenurus. Exophthalmos resolved with surgical therapy and there was no evidence of recurrence or postoperative complications over a period of 2 years. To the authors' knowledge, this is the first reported case of an orbital cyst of parasitic origin in a chinchilla.     

First report of naturally acquired clinical sarcocystosis in a pig breeding stock

A two-year-old Large White boar from a pig breeding stock in an indoor farm in Switzerland presented anorexia, reduced general condition and fever. Despite antibiotic and anti-inflammatory treatment, the boar developed severe dyspnoea and cyanosis, and died after 4 days. At necropsy, no gross lesions were observed. Histopathologically, multifocal degeneration and necrosis of myocardial fibers with interstitial edema, severe multifocal non-suppurative myocarditis and hepatitis, and non-suppurative interstitial nephritis were observed. In heart samples, groups of organisms resembling apicomplexan tachyzoites were seen associated with the lesions. A PCR using the primers COC1-COC2 that target a conserved region of the small-subunit rRNA gene of Apicomplexa was performed with DNA from paraffin-embedded tissues. An amplification product of about 350 bp was obtained from heart samples. A sequence analysis showed 100% identities with GenBank sequences reported for Sarcocystis miescheriana. The histopathological observations and molecular findings in combination with the clinical signs, and absence of other pathologic agents highly suggested that an acute infection with S. miescheriana was the cause of death in this boar. To our knowledge, this the first report of fatal acute sarcocystosis after natural infection in a pig breeding herd.     

Yersinia enterocolitica. Experimental pathogenicity for chinchilla.

An intragastric inoculation of approx. 2 × 10¹⁰ Yersinia enterocolitica cells killed chinchillas in three days in the case of four strains out of six tested. Because of the sensitivity of chinchillas to this bacterium, the test is useful for the evaluation of the virulence and invasiveness of Y. enterocolitica isolates. This animal model could also be used for studies on the mechanism of the infection.     

Echocardiography in the chinchilla

Heart disease has been described in the chinchilla and, with increasing popularity as a pet, the demand for diagnostic evaluation and treatment has increased. The goal of this study was to determine reference values for echocardiographic measurements in chinchillas and the effect of anesthesia on these measurements. Seventeen clinically healthy adult chinchillas were studied. All animals were anesthetized with isoflurane by mask. Standard echocardiographic views were used. A difference was seen in the echocardiographic measurements for left ventricular systolic dimension, fractional shortening, aortic (Ao) diameter, left atrial (LA) diameter, ratio of LA diameter to Ao diameter, and peak flow velocities and ejection times for Ao and pulmonary artery flows between awake and anesthetized chinchillas.