Table 1. Evidence that N. caninum infection was present in the foetuses and placentae of all eight cows following parasite recrudescence.

Animal number	Week of gestation when evidence of recrudescence was first detected (week of euthanasia)	Detection of parasite DNA in foetal brain	Detection of parasites by immunohistology in foetus or placenta		Placental necrosis
			Foetus	Placenta
1	20 (22)	+, +*	−	+ (6/10)	+
2	22 (25)	+	+	−	+
3	22 (25)	+	−	−	+
4	26 (28)	+	+	+ (1/10)	+
5	27 (32)	+	+	−	+
6	30 (32)	+	−	+ (1/10)	+
7	32 (35)	+, −*	−	−	+
8	33 (35)	−	+	−	+

Detection of parasites or parasite-associated necrosis in the placenta and foetal tissues of ten foetuses obtained from eight naturally persistently N. caninum-infected cattle killed two to five weeks after first detection of evidence indicating parasite recrudescence had occurred. All ten foetuses were alive when the dams were euthanized as shown by ultrasound scanning to detect foetal heartbeat. Tissues were obtained within one hour of death. For histology and immunohistology, 10 full-thickness pieces of placentome from each animal were collected and brain, heart, spinal column and liver were collected from the foetuses. Two cows were carrying twins thus ten foetuses were examined. No parasite DNA was detected by PCR in any placental tissue samples analysed.

*where two symbols are given this denotes a value for each twin.