SARCOCYSTIS, TOXOPLASMA AND RELATED PROTOZOA 



333 



and contain grey, necrotic foci. There 

 may be ulcers in the oral, gastric and 

 intestinal mucosa; this ulceration is per- 

 haps more common in dogs than in other 

 animals. Lymphadenitis, hydrothorax, 

 ascites, nephritis, pancreatitis and 

 vaginitis may also be present. 



None of the 16 cases described by 

 Campbell, Martin and Gordon (1955) had 

 clinical signs which could be regarded as 

 specific for Toxoplas»ia infection, altho 

 the effects of this parasite may have been 

 masked by intercurrent distemper. They 

 found Toxoplasma in the lungs of 7 dogs, 

 the mediastinal lymph nodes of 6, the 

 mesenteric lymph nodes of 2, the heart 

 muscle of 8, the liver of 4, the pancreas 

 of 3, the spleen of 4, the kidneys of 3, 

 the urinary bladder of 3 and the brain of 

 10. 



Makstenieks and Verlinde (1957) re- 

 ported encephalitis in one infected cat and 

 abortions in another. However, Simitch 

 et al. (1960) reported that the cat is rel- 

 atively refractory to infection. They 

 could not infect adult cats with 3 strains 

 of T. gondii by either intravenous, intra- 

 peritoneal, subcutaneous or oral inocula- 

 tion, and only part of the kittens less than 

 2 to 3 months old which were exposed by 

 these routes became infected. 



The disease in swine is similar to 

 that in dogs. Pneumonitis, ulcerative 

 enteritis, focal hepatitis, nephritis and 

 splenitis have been described. Young pigs 

 are much more susceptible than adults. 



The disease in cattle is similar to 

 that in dogs, and may vary considerably 

 in its manifestations. In 1 herd described 

 by Sanger et al. (1953), 3 cows developed 

 nervous signs and died, and a fourth, 

 asymptomatic cow which reacted posi- 

 tively to the toxoplasmin skin test was 

 found to have the organisms in her colo- 

 strum, uterine wall, spleen and lung. In 

 addition, 3 of 31 calves in this herd were 

 born dead, and 4 developed an obscure 

 disease of which 2 died. In a second herd, 

 45 of 78 calves died between the ages of 1 

 day to 6 months with signs of dyspnea, 

 coughing, sneezing, nasal discharge, 

 frothing at the mouth, trembling, head- 



shaking, dehydration and occasionally 

 diarrhea with blood and mucus. Toxo- 

 plasma was recovered from the lungs of 



1 calf. In a third herd, a bull died a week 

 after the onset of illness characterized by 

 anorexia, weakness, ataxia, prostration, 

 chewing movements and bicycling; Toxo- 

 plasma was found in his brain. In a fourth 

 herd. Toxoplasma was found in various 

 tissues of a 7-year-old cow which had died 



2 weeks after parturition with signs of 

 anorexia, diarrhea, depression, fever and 

 mastitis. Some calves in this herd later 

 died of an undiagnosed disease. 



In sheep, Olafson and Monlux (1942) 

 and Wickham and Carne (1950) described 

 cases of non-suppurative encephalomye- 

 litis with nervous signs. Cole et al. (1954) 

 isolated Toxoplasma from a flock of sheep 

 in which several ewes and lambs died of a 

 disease with respiratory and nervous signs. 

 Hartley and Marshall (1957) found that 

 toxoplasmosis is an important cause of 

 perinatal mortality in sheep in New Zea- 

 land. The overall perinatal mortality 

 rate in sheep in this country is 10 to 15% 

 and at least 1/5 of the deaths are due to 

 potentially pathogenic organisms. Of 

 these Toxoplasma is considered the most 

 widespread and important. In a study of 

 30 lambs which died of toxoplasmosis on 

 15 farms, Hartley and Marshall considered 

 that 2/3 died before birth and the other 

 third died either at the end of an apparently 

 normal parturition or a few hours after- 

 wards. The cotyledons of the fetal mem- 

 branes bore small, necrotic foci which 

 contained clumps of proliferative tropho- 

 zoites. 



Ratcliffe and Worth (1951) described 

 an epidemic of toxoplasmosis in squirrel 

 monkeys [Saimiri sciiirea) in the Phila- 

 delphia Zoo, and Benirschke and Richart 

 (1960) described a fulminating acute case 

 in a young cotton-topped marmoset 

 (Oedipomidas oedipus). 



In naturally affected chickens, Bie- 

 ring-Sorensen (1956) reported that emac- 

 iation and central nervous system signs 

 were the principal signs. Necrosis of the 

 optic chiasma and of the retina with cellu- 

 lar infiltration were characteristic. 

 Erichsen and Harboe (1954) described 



