THE TELOSPORASIDA AND THE COCCIDLA PROPER 



167 



and upper colon in heavy infections. 

 Young oocysts still in the host cell nuclei 

 first appear 6 days after infection. Mul- 

 tiple infections are common, as many as 

 3 schizonts or microgametocytes and 4 or 

 5 macrogametes or oocysts having been 

 found in a single host cell nucleus. This 

 crowding may affect the shape of the 

 oocysts in heavy infections, making some 

 of them wedge-shaped or asymmetrical. 



The prepatent period in experimentally 

 infected calves was found by Davis, Bough- 

 ton and Bowman (1955) to range from 6 to 

 13 days with a mean of 8 to 9 days. The 

 patent period ranged from 1 to 10 days with 

 a mean of 4. 6 days in 21 low-grade infec- 

 tions, and from 1 to 13 days with a mean 

 of 7. 2 days in 72 heavy infections. 



Pathogenesis : Under field conditions, 

 E. alabainensis is considered essentially 

 non- pathogenic. However, Boughton (1943) 

 produced clinical coccidiosis in 5 young 

 calves by feeding them 200 million oocysts. 

 Within 5 days they developed a severe 

 diarrhea, with yellowish feces having a 

 characteristic acrid odor. They become 

 thin, and 1 calf died on the 8th day and 

 another on the 14th. In the first calf the 

 lower half of the small intestine was hy- 

 peremic and there was massive tissue in- 

 volvement with merozoites and macro- 

 gametes. In the second calf there was 

 enteritis in only the last 3 feet of the 

 ileum, and only a few parasites remained 

 in the tissues, most of these being within 

 1 foot of the ileocecal valve. 



Davis, Boughton and Bowman (1955) 

 fed two 14-month-old calves 140 million 

 oocysts. One became diarrheic on the 

 fifth day. Its feces were watery, yellow- 

 ish green, with some bloody mucus and a 

 sharp, acrid odor. The diarrhea grad- 

 ually subsided. In the second calf the 

 feces were soft toward the end of the pre- 

 patent period. A 7-month-old heifer which 

 had previously been exposed to coccidial 

 infection had a slight diarrhea on the 9th 

 and 11th days following similar exposure, 

 and a 2-year-old cow remained normal. 



Immunity : Reinfection is considered 

 common in the field. Davis, Boughton and 



Bowman (1955) reported that in 58 attempts 

 to reinfect calves 2 or more times, there 

 were 39 high-grade infections, 11 low- 

 grade infections and 8 failures. Nine of 

 the low-grade infections and 7 of the fail- 

 ures followed the third or subsequent in- 

 oculations. Some animals were reinfected 

 as many as 4 times before reinfection at- 

 tempts failed. 



EIMERIA AUBURNENSIS 

 CHRISTENSEN AND PORTER, 1939 



Synonym : Eimeria ildefonsoi Torres 

 and Ramos, 1939. 



Hosts : Ox. In addition, Bohm and 

 Supperer (1956) reported finding this spe- 

 cies in a wild roe deer in Austria, but 

 gave no morphological information on it. 



Location: Unknown. Oocysts found 

 in feces. 



Geographic Distribution : North 

 America, South America (Brazil), Europe 

 (Austria, Spain, England). 



Prevalence : E. anbiiruensis is one of 

 the commonest coccidia of cattle in North 

 America. Davis and Bowman (1952) found 

 it in all of 20 calves in Alabama. Hasche 

 and Todd (1959) found it in 45% of 355 

 cattle in Wisconsin. Torres and Ramos 

 (1939) found it in 32% of 146 cattle in Brazil. 

 Supperer (1952) found it in 3% of 130 cattle 

 in Austria. According to Lapage (1956), 

 Watkins found it in 91% of the calves he 

 examined in Devonshire. 



Morphology : The oocysts have been 

 described by Christensen and Porter (1939) 

 and Christensen (1941). They measure 32 

 to 46 by 20 to 26 fi with a mean of 38. 4 by 

 23. 1 ILL. Their length-width ratios range 

 from 1 . 32 to 2. 08 with a mean of 1 . 67. 

 They are typically elongate ovoid, but vary 

 between sub-ellipsoidal and markedly ta- 

 pered. The micropyle appears as a thin, 

 pale area at the small end in unstained 

 specimens, but when stained with iodine- 

 eosin in physiological salt solution, a def- 

 inite gap covered by a narrow black line 

 which may be a flat operculum is seen. 



