Other species of Giardia
Giardia caprae Nieschulz, 1923 (syn., G. ovis) was reported from the anterior part of the small intestine of 2 goats in Holland. Nieschulz (1924) described it further. Its trophozoites are 9 to 17 u long and 6 to 9 u wide with a mean of 13.5 by 7.5 u. The median bodies are curved bars of the duodenalis type. The cysts have 4 nuclei and measure 12 to 15 by 7 to 9 u with a mean of 14 by 8 u.
Giardia caprae was found by Grassi (1881) in sheep in Italy and by Turner and Murnane (1932) in the small intestine of sheep in Australia. The Australian sheep had been losing weight gradually for several months. Deas (1959) found it in a lamb with enteritis in England. D. A. Willigan (unpubl.) found Giardia in 3 of 24 lambs brought to the University of Illinois Veterinary Diagnostic Service. All came from a single flock in which many of the lambs were suffering from diarrhea and loss of weight, but coccidiosis and salmonellosis were also found. Dissanaike (1953) found live and active G. caprae in the intestines of 50 female and no male Nematodirus filicollis from 5 sheep in England.
Giardia equi Fantham, 1921 was originally found in the large intestine of a horse in South Africa. Varela and Salsamendi (1958) found it in the feces of a horse with colic in Venezuela. Its trophozoites measure 17 to 21 by 9 to 12 u, and its cysts measure 12 to 16 by 8 to 9.5 u.
Giardia duodenalis (Davaine, 1875) (syns., Hexamita duodenalis, Larnblia cuniculi) occurs in the anterior small intestine of Old and New World rabbits and also in Coendu villosus in Brazil. It occurs sporadically and is apparently not pathogenic. Its trophozoites measure 13 to 19 by 8 to 11 u with a mean of 16 by 9 u. The median bodies are curved bars resembling the claws of a claw-hammer; th they lie transversely across the body. The cysts contain 2 to 4 nuclei.
Giardia simoni Lavier, 1924 occurs in the anterior small intestine of the Norway rat, golden hamster and probably various wild rodents. Its trophozoites measure 11 to 19 by 5 to 11 u. Its median bodies are curved bars of the duodenalis type.
G. muris (Grassi, 1879) occurs in the anterior small intestine of the house mouse, Norway rat, black rat, golden hamster and various wild rodents. It is common in laboratory rats and mice. Its trophozoites measure 7 to 13 by 5 to 10 u. Its median bodies are small and rounded.
G. caviae Hegner, 1923 occurs in the anterior small intestine of the guinea pig. Its trophozoites measure 8 to 15 by 6.5 to 10 u. Its median bodies are curved bars of the duodenalis type.
Giardia chinchillae Filice, 1952 emend, (syn., Giardia duodenalis race chinchillae Morgan, 1949 of Filice, 1952; altho he gave the first description of this form, Morgan did not give it a specific name; the name chinchillae was introduced by Filice) occurs frequently in the chinchilla. It is found thruout the small intestine, but more commonly in the duodenum and anterior jejunum. Its trophozoites measure 11 to 20 by 6 to 12 u. Its median bodies are curved bars of the duodenalis type. This species has been accused by various workers of causing diarrhea and even death (Shelton, 1954; Gorham and Farrell, 1955). Treatment with 6 to 9 mg quinacrine for 5 to 7 days was found by Hagan (1950) to eliminate the infection. Attempts to transmit G. chinchillae to the golden hamster, white mouse, domestic rabbit or guinea pig have been unsuccessful (Morgan, 1949; Shelton, 1954).