Fatal disseminated toxoplasmosis in an immunocompetent cat

Abstract

A 10-year-old domestic short hair cat was referred for investigation of anorexia and polydipsia of 3 days' duration. Clinically the cat was obese, pyrexic (39.8 °C), had acute abdominal pain and severe bilirubinuria. Haematology and serum biochemistry revealed severe panleukopenia, thrombocytopenia, markedly elevated alanine aminotransferase (ALT) and five-fold increased pre-prandial bile acids. Ultrasonographic evaluation of the abdomen did not identify any abnormalities. Serum tests for feline immunodeficiency virus (FIV) and feline leukaemia virus (FeLV) were negative. Broad-spectrum antibiotic treatment for infectious hepatitis was to no avail; the cat deteriorated and died 72 h after admission. Necropsy revealed mild icterus and anaemia, severe multifocal hepatic necrosis, serofibrinous hydrothorax, pulmonary oedema and interstitial pneumonia. Histopathology confirmed the macroscopic findings and revealed multifocal microgranulomata in the brain and myocardium, as well as areas of necrosis in lymph nodes and multifocally in splenic red pulp. Long bone shaft marrow was hyperplastic with a predominance of leukocyte precursors and megakaryocytes and splenic red pulp showed mild extramedullary haemopoiesis. Immunohistochemical staining for Toxoplasma gondii was strongly positive, with scattered cysts and tachyzoites in the liver, lymph nodes, spleen, lungs, brain, salivary glands and intracellularly in round cells in occasional blood vessels. Immunohistochemical staining for corona virus on the same tissues was negative, ruling out feline infectious peritonitis (FIP). Polymerase chain reaction (PCR) on formalin-fixed paraffin-wax embedded tissues was positive for Toxoplasma sp., but attempts at sequencing were unsuccessful. This was the first case report of fulminant disseminated toxoplasmosis in South Africa, in which detailed histopathology in an apparently immunocompetent cat was described.

Fatal toxoplasmosis in an immunosuppressed domestic cat from Brazil caused by Toxoplasma gondii clonal type I

“…The definitive diagnosis was obtained after the patient's death, by means of histopathological analysis, like in most other cases that have been reported (HENRIKSEN et al, 1994;LAST et al, 2004;SPYCHER et al, 2011;JOKELAINEN et al, 2012;NAGEL et al, 2013;COHEN et al, 2016). However, cytological analysis on the bronchoalveolar lavage to directly detect tachyzoites might have elucidated the clinical case (HARTMANN et al, 2013).…”

“…The main histological lesions in the present case were necrotic interstitial pneumonia and necrotic hepatitis, which were similar to the lesions described in the reports from the authors cited above. However, in some cases, necrosis was described in the spleen and lymph nodes, along with myocarditis, pancreatitis, adrenalitis, meningoencephalitis and uveitis (DAVIDSON et al, 1993;HENRIKSEN et al, 1994;LAST et al, 2004;SPYCHER et al, 2011;JOKELAINEN et al, 2012;NAGEL et al, 2013;COHEN et al, 2016). These lesions were not observed in the present study.…”

“…However, fatal systemic cases have been reported in immunocompetent cats (SPYCHER et al, 2011;JOKELAINEN et al, 2012;NAGEL et al, 2013;COHEN et al, 2016) and in immunocompromised cats after administration of immunosuppressant drugs (LAST et al, 2004) and kidney transplantation (BERNSTEEN et al, 1999). Coinfection with immunosuppressant retroviruses such as FIV has also been reported to be a risk factor for development of a clinical condition of toxoplasmosis (DAVIDSON et al, 1993).…”

Global miRNA expression profiling of domestic cat livers following acute Toxoplasma gondii infection

“…8, (No. 15), pp: 25599-25611 Research Paper [4][5][6][7]. Hence, cats are unique in respect of their ability to accommodate both sexual and asexual reproductions of T. gondii, making cats a significant source of infection to humans and animals [2,8].…”

“…Besides the adverse clinical consequences on humans and other intermediate hosts T. gondii can cause disseminated and fatal infection in cats [4][5][6][7]9]. Although any organ in the cat's body can be affected, clinical cases related to hepatic and pulmonary damage are particularly important because they are associated with quicker mortality [6,[10][11][12]. Also, liver dysfunction, enlargement, icterus, cholangiohepatitis, vomiting, abdominal effusion, and ascites are complications that frequently occur in T. gondii-infected cats.…”