Table 1.

Diagnostic procedures for common infectious agents

Agent	Sample	Test	Testing time	Comments
Clostridium difficile	Faeces	Toxin A/B ELISA	Minutes to hours
Clostridium perfringens	Faeces	Enterotoxin ELISA	Minutes to hours	High sensitivity; samples should be kept cool (not frozen) if possible
Clostridium spp.	Faeces	Culture	Days to weeks	Low specificity; samples should be transported anaerobically
Salmonella spp.	Faeces	Culture	Days to weeks	5 samples needed to conclude negative
	Faeces	PCR	Hours to days	High sensitivity, specificity variable
Neorickettsia risticii	Faeces, plasma	PCR	Days to week	Collect samples prior to treatment
	Blood	IFA	Days to week	Poor sensitivity
Rotavirus	Faeces	ELISA	Minutes to hours	High sensitivity, equal or better than EM
Coronavirus	Faeces	PCR	Hours to days
Lawsonia intracellularis	Faeces	PCR	Days	Poor sensitivity, best to submit both tests
	Tissue
	Serum	IFA	Days to week	Best to submit both tests
Cryptosporium parvum	Faeces	Acid fast stain	Minutes to hours
		IFA	Days to week
Strongyloides westeri	Faeces	Faecal float	Minutes to hours	Prepatent period of 5–7 days
All viruses and protozoa	Faeces	Electron microscopy	Days to weeks	Poor sensitivity depending upon sample, very specific