Lecture 7- treatment and control of parasitic infections in dogs and cats

What is the primary goal in the treatment of parasitic infections in dogs and cats?

The primary goal is the removal of parasites from the host.

Which parasites are often targeted for removal from the host?

Blood-sucking hookworms in puppies and adult roundworms occluding the intestinal lumen

What is the treatment objective related to parasite development?

To interrupt parasite development, especially targeting migrating and arrested larvae in the tissue.

How can transmission between infected and susceptible hosts be prevented?

By addressing larval transmission through lactogenic and transplacental routes and reducing environmental contamination.

How can transmissible parasite stages be reduced in the environment?

By reducing environmental contamination and implementing hygiene measures.

What is the approach for suppressive treatment of parasitic infections?

Suppressive treatment is given at intervals shorter than the parasite's environmental reappearance period (ERP).

What characteristics should drugs have for treating animals with clinical GI parasitic infections?

Drugs should be fast-acting, broad-spectrum, efficacious, and have a wide margin of safety.

What is Pyrantel pamoate effective against?

Pyrantel pamoate is effective against hookworms and roundworms.

What is the safety margin for Pyrantel pamoate?

Pyrantel pamoate has a high margin of safety (x135).

In which product is Pyrantel pamoate commonly used?

Pyrantel pamoate is used in products like HeartGard Plus.

What parasites is Fenbendazole (FBZ) effective against?

Fenbendazole is effective against hookworms, roundworms, and whipworms.

What is the safety margin for Fenbendazole?

Fenbendazole has a high margin of safety (x5 daily dose; 250 mg/kg).

How long should Fenbendazole be administered for effective treatment?

Fenbendazole should be administered for 3 days.

What is Pyrantel effective against?

Pyrantel has broad-spectrum activity for nematode parasites in the GI, such as Ancylostoma and Toxocara.

What is the mechanism of action of Pyrantel on nematodes?

Pyrantel has a nicotine-like effect on acetylcholine receptors (nAChR), causing hyper-stimulation of muscle cell receptors.

What is the result of Pyrantel's agonist-activity on nematode muscles?

The result is continuous muscle contractions leading to spastic paralysis.

What happens to nematode parasites after Pyrantel causes spastic paralysis?

Nematode parasites cannot feed or stay in place, leading to their death.

What other type of drugs shares a similar mechanism of action with Pyrantel?

Organophosphate (OP) insecticidal drugs share the same mechanism of action.

What happens when Pyrantel and organophosphate drugs are used together?

Using them together may potentiate toxicity, leading to symptoms like involuntary muscle twitching, vomiting, and tremors.

How does Fenbendazole work on nematodes?

Fenbendazole preferentially binds to ß-tubulin molecules of nematodes, disrupting microtubule function at the cellular level.

What are the cellular effects of Fenbendazole's action on nematodes?

Fenbendazole adversely affects cell division, maintenance of cell shape, nutrient absorption, and intracellular transport.

What secondary enzymatic activities are inhibited by Fenbendazole?

Fenbendazole inhibits acetylcholinesterase (cholinergic function) and fumarate-reductase (anaerobic respiration).

How does Fenbendazole lead to parasite death?

Fenbendazole causes energy deprivation in parasites, leading them to starve and die.

How selective is Fenbendazole in its toxicity?

Fenbendazole has selective toxicity to parasites with a safety margin in dogs and cats.

When should puppies be dewormed to prevent parasitic infections?

Puppies should be dewormed at 2, 4, 6, and 8 weeks of age.

What is the purpose of suppressive treatment in parasitic control?

Suppressive treatment targets advanced parasite larvae as they complete migration to the GI, preventing sexual maturation, reproduction, contamination, and reinfection.

What are common drug choices for treating parasitic infections in dogs and cats?

Pyrantel pamoate (Strongyid) and Fenbendazole (Panacur/Safeguard) are commonly used drugs.

What is the role of monthly heartworm drugs in parasite prevention?

Monthly heartworm drugs, such as Interceptor, HeartGard Plus, and Advantage Multi, help prevent parasitic infections, including hookworms, roundworms, and whipworms.

When should Interceptor (Milbemycin) be administered to puppies?

Interceptor should be administered to puppies at 4 weeks of age to target hookworms, roundworms, and whipworms.

When should HeartGard Plus (IVM + Pyrantel) be administered to puppies?

HeartGard Plus should be administered to puppies at 6 weeks of age to target hookworms and roundworms.

When should Advantage Multi (Imidacloprid + Moxidectin) be administered to puppies?

Advantage Multi should be administered to puppies at 7 weeks of age to target hookworms and roundworms.

How is Fenbendazole (FBZ) used to control prenatal and perinatal parasitic infections?

Fenbendazole is given daily from the 40th day of gestation through the 14th day of lactation to prevent neonatal hookworm and prenatal roundworm infections.

What is the recommended dose of Ivermectin (IVM) for preventing lactogenic transmission of Ancylostoma in dogs?

A single treatment of Ivermectin (500 μg/kg) 4 to 9 days prior to whelping and 10 days post-whelping is satisfactory for preventing lactogenic transmission of Ancylostoma.

What is the recommended dose of Ivermectin (IVM) to reduce transplacental transmission of Toxocara canis in puppies?

Heroic treatments of Ivermectin (1000 μg/kg) at days 20 and 42 of gestation help reduce the number of Toxocara canis transmitted transplacentally to puppies.

How does the dose of Ivermectin for heartworm prevention compare to the dose for controlling prenatal parasitic infections?

the dose for heartworm prevention is 6 to 8 μg/kg (once monthly), whereas for controlling prenatal parasitic infections, a substantially higher dose (500-1000 μg/kg) is required.

Why is there significant concern when using Ivermectin in animals with the MDR1 genetic mutation?

Animals with the MDR1 mutation have a deficit in p-glycoprotein, which normally transports drugs away from the brain, potentially causing toxic accumulation of drugs like Ivermectin.

What is an important role veterinarians and vet techs play in preventing parasitic infections?

Veterinarians and vet techs play an important role in client education on proper hygiene and prevention practices.

Why is it important to remove feces from yard and play areas?

Removing feces helps prevent the spread of parasites, reducing contamination in the environment.

How can sandboxes be kept hygienic to prevent parasitic infections?

Keep sandboxes covered when not in use to prevent contamination from feces or parasites.

Why is it important to wash hands after pet contact?

Washing hands after pet contact helps prevent the transmission of parasites and other pathogens to humans.

Why should dogs be cleaned promptly if they roll in something potentially contaminated?

Cleaning dogs promptly helps prevent the spread of parasites and pathogens that may be present in the environment.