Veterinary Parasitology CH2 - Parasites That Infect and Infest Domestic Animals

Study material for Chapter 2 of Diagnostic Parasitology for Veterinary Technicians. For class BIO225 at MWCC.

Monogentic Trematodes (Flukes)

• Do not alternate generations

• Kingdom: Animalia​, Phylum: Platyhelminthes (flatworms)​, Class: Trematoda (flukes)​, Subclass: Monogenea

• Ectoparasites of fish, amphibians and reptiles​

• Adults hatch out of eggs​

• In high numbers can cause fin rot, anemia

Digenetic Trematodes (Flukes)

• Alternate between sexual and asexual generations

• Kingdom: Animalia​, Phylum: Platyhelminthes (flatworms), Class: Trematoda (flukes)​, Subclass: Digenea

• Endoparasites of large and small animals

• Flat, leaf-shaped, infect mostly GI, also lung and blood​

• Eggs can be seen in feces

• Have both larval and adult stages, often in different hosts

Eucestodes (True Tapeworms)

• Kingdom: Animalia​, Phylum: Platyhelminthes (flatworms), Class: Eucestoda (true tapeworms)

• Ribbon-like, found in GI tract of definitive hosts​

• Lack an alimentary canal, absorb nutrients through tegument (skin)​

• Eggs can be seen in fecal flotation​

• Larval forms can be found in various tissues of intermediate hosts and cause harm

Cotyloda​ (Pseudotapeworms)

• Kingdom: Animalia​, Phylum: Platyhelminthes (flatworms)​, Class: Cotyloda (pseudotapeworms)

• Ribbon-like, found in GI tract of definitive hosts​

• Eggs can be seen in fecal flotation​

• Larval forms can be found in various tissues of intermediate hosts (microscopic crustaceans, fish and reptiles) but don't cause harm to domestic animals

Nematodes (Roundworms)

• Kingdom: Animalia, Phylum: Nematoda

• Long, not segmented, most numerous and varied of domestic worm parasites. Can cause significant disease in domestic animals

• Eggs and larvae can be seen in fecal flotation

Acanthocephalans ​(Thorny-Headed Worms)

• Kingdom: Animalia, Phylum: Acanthceophala

• Long, not segmented, contain spiny proboscis used to attach to host tissue​

• Lack an alimentary canal, absorb food through tegument ​

• Very uncommon to see adult parasites​

• Most often seen in GI tract​

• Eggs can be seen in fecal flotation

Hirudineans (Leeches)

• Kingdom: Animalia​, Phylum: Annelida (segmented worm)​, Class: Hirudinea

• Blood-feeding, ringed ectoparasites of wild and domestic animals

• Mostly fresh-water, some marine and land varieties

Arthropods

• Kingdom: Animalia​, Phylum: Arthropoda (jointed legs)

• Largest phylum in all of the animal kingdom​

• Contains pentastomes, crustaceans, centipedes, millipedes, insects, mites, ticks, scorpions and spiders​

• May be causal agents, intermediate hosts, vectors, produce toxins or venoms

Protozoans

• Kingdom: Protista

• All are unicellular protozoans​

• Categorized by their movement: flagellates, amoebae, apicomplexans and ciliates​

• Can cause significant pathologies to all animals including humans