Infections with gastrointestinal nematodes (GIN), liver, and rumen fluke and lungworm are common parasitic infections in grazing cattle, causing a decline in the animals’ health and well-being. The diagnosis of gastrointestinal nematode infection is based on the fecal egg count (FEC). There are various techniques for diagnosing GIN infection, including the McMaster technique, the modified Wisconsin protocol, FECPAK, and Mini-FLOTAC. More recently, new on-site diagnostic systems have been developed, incorporating a smartphone app or machine learning, based on automatic image recognition and helminth egg counting, such as OvaCyte, FECPAKG2, and Micron Kit. Most strongyle eggs are morphologically similar, so the identification of third-stage larvae (L3) of these genera recovered from fecal cultures is useful in differentiating between genera. The Baermann method reveals the presence of first-stage larvae (L1) of lungworms.