Parasitology Treatments and Life Cycles

Parasitology Treatments

• The course is about treatments for parasites
• Learning objectives include describing generic antiparasitic drugs
• Students will learn about specific indications and drug selection
• Students will compare and contrast antiparasitic drug attributes
• Drug use for prevention and treatment will be covered
• Proper drug administration methods (oral, topical, injectable) will be discussed
• Off-label/extra-label drug use, including use for minor species, will be addressed
• Withdrawal times for food animals and drug resistance issues will be covered

Life Cycles

• A general review of parasite life cycles is planned for a Monday exam
• When considering parasites, species of host and drug use within species should be considered
• Drugs need to target the appropriate life stage of the parasite (adult vs larval)
• Contraindications, like milk clearance time in food animals, and environment shedding of parasites should be acknowledged

Methods of Parasite Control

• Raising animals in a parasite-free environment is a control method
• Administration of parasite-specific vaccines is discussed
• Biological control through nematophagous fungi is mentioned
• Other non-chemical control methods and bioactive forages are noted
• Chemotherapy using anthelmintics and ectoparasiticides is mentioned

Extra-Label Drug Use

• Extra-label use is a privilege of veterinarians
• Use is permitted when a veterinarian-client-patient relationship exists and proper diagnosis exists
• Proper dosage, labeling, records, and withdrawal times need to be considered
• Labeling of drug and efficacy are noted as important to drug use
• Extra-label use may be chosen if labeled drugs are unavailable or have failed (resistance)
• Published data supporting application of extra-labeled drug use is highlighted
• Cost is not an acceptable justification for using extra-labeled drugs

Strategies For Parasiticide Use

• Therapeutic use of drugs is for treatment
• Prophylactic use is for prevention
• Strategic use is for control through timed intervals to maximize outcome

Categories of Parasiticides

• Endoparasiticide: kills internal parasites
• Ectoparasiticide: kills external parasites
• Endectocide: kills both internal and external parasites
• Categories are also distinguished via their target group, i.e., protozoa, helminths (worms), and arthropods (insects/arachnids)
• Ivermectin is used for endoparasites

Antiprotozoals

• These drugs target protozoan parasites
• Various chemical structures are shown and their mechanism of action is detailed (including how they inhibit DNA/RNA synthesis)

Anthelmintics

• These drugs target helminths (worms). They target multiple parasite types (cestodes, trematodes, etc.)
• Mechanisms of action include interference with parasite neurotransmission, interference with parasite reproduction, and anti-cestodal and anti-trematodal drugs.

Categories of Anthelmintics

• Nematocides target nematodes
• Flukicides target flukes
• Cestocides target cestodes

Anthelmintics Administration

• Administration routes include oral, topical, and injection
• Frequency varies and includes daily, monthly, and PRN

Major Classes of Anthelmintics

• Classes include benzimidazoles, avermectin/milbemycins, membrane depolarizers, isoquinoline, cyclodepsipeptides and arsenicals

Ectoparasiticides

• Ectoparasiticides target external parasites, including ticks, mites, fleas, flies, and lice.
• Drugs may be applied to the animal or the environment

Examples of Ectoparasiticides

• Insecticides, acaricides, repellents, insect growth regulators, insect development inhibitors, and synergists fall under this category.
• Many are used for pet and agricultural settings

Life Cycle- Kill the adults and babies

• Understanding the life cycle is important for effective parasite control.
• Adulticides kill adults
• IGSRs kill larval stages of parasites

Ectoparasiticide Administration

• Topical administration (spot-on, sprays, dips, shampoos, collars) are common
• Systemic via oral, parenteral, and topical routes are other methods of administration
• Environmental administration (premises sprays, foggers, dusts)

Insecticide and Acaricide Administration

• Various routes for application (environmental, topical, systemic)

Exam Information

• The exam covers parasitology lectures 1-3.

This quiz covers essential treatments for parasites, focusing on generic antiparasitic drugs and their indications. Students will review parasite life cycles, drug administration, and relevant considerations for specific species. Additionally, issues like drug resistance and withdrawal times for food animals will be addressed.