Internal Parasites and Deworming
Managing Intestinal Parasites in Dogs and Cats
November 29, 2022
Managing Intestinal Parasites in Dogs and Cats
Last updated: August 18, 2022 by Marty Greer, Doctor of Veterinary Medicine
Intestinal parasites have been around since dinosaurs and are not going away – you need to manage them. Parasites do not want to kill your pets; they want to use them as a dinner plate. These parasites are like to drag your pets down, causing rough hair coats, diarrhea, or anemia. Managing your parasites is not about deworming more or with more products. It is about using the correct dewormer at the right time to get the biggest effect for your time and money.
Small Intestine Parasites: Upper GI
It helps to know the parasites we are targeting. Roundworms and hookworms live in the small intestine. The adults are easy to get rid of as most dewormers are active in the small intestine.
- Roundworms are three to seven inches long and look like spaghetti. If puppies or kittens are vomiting parasites, it is roundworms. If you have a lot of roundworms, they can be seen in the stool. Roundworms are usually digested before they get through the intestinal tract.
- Hookworms are tiny (½” long) and difficult to see without a microscope. They attach to the wall of the intestine, and suck blood from the intestinal wall. They migrate through the intestinal wall, into the mammary glands, so they are transmitted to the puppies in the milk.
- Both roundworms and hookworms can migrate through tissue, especially the liver. They get back to the intestine by migrating to the lungs where they are coughed up and swallowed. Once back in the intestine, they complete the life cycle and reproduce.
- Parasites can play a role in the eight-week-old puppy cough.
- Migrating stages are resistant to dewormer when outside of the intestinal tube. Once you get rid of the adults in the intestine, the larvae can pop out of the tissue and set up in the intestine you just cleared.
- Both roundworms and hookworms can infect humans and must be managed to protect the family members before sending puppies and kittens to a new home!
Large Intestine Parasites: Lower GI
Tapeworms and whipworms take up residence in the large intestine. They are about 20 feet down from the mouth so getting dewormer to stay active is difficult.
- Tapeworms are as different from other intestinal parasites as cats are from dogs. They mostly live on dog waste and can cause colitis and irritation of the rectal area. Treatment with Praziquantel will eliminate adults.
- Egg packets are passed and look like rice in the feces or on the rectal area. These eggs have to mature in an intermediate host (fleas, mice, or birds), and once that host is eaten by the dog or cat, they get tapeworms. If you prevent them from getting the intermediate host, you can stop tapeworms.
- These parasite segments are difficult to detect on routine fecal testing so may not be noted as present.
- Cat and dog flea control is also an essential part of tapeworm control. Use Revival's Flea and Tick Finder to help choose the best treatment for fleas on dogs and cats.
- Whipworms are killed by few dewormers. Preventing re-infection is the key with whipworms that are directly infective. They will seed an exercise area down, mature, and another dog or cat will ingest them. Raised decks prevent the re-infections and break the lifecycle. Even the coldest winter weather will not interrupt the lifecycle of the whipworm.
Coccidia and Giardia in Dogs and Cats
Giardia and Coccidia in dogs and cats are active throughout the intestine, but they are considered small intestinal parasites.
- Both Coccidia and Giardia are tiny and are diarrhea-causing opportunists. Many causes can initiate diarrhea, and they keep it going.
- Coccidia control involves keeping the numbers so low in the kennel that you rarely need to treat. Prevention drugs are effective. Much the same is true of Giardia.
- We try and get rid of Giardia, but it always seems to be around so prevention is the key to control.
Deworming Adult Dogs and Cats
Adults are the backbone of preventing parasites. The fewer parasites mom passes to the babies, the fewer we need to manage out of our babies. Males are dewormed twice a year, and moms are dewormed during the last three weeks of the pregnancy daily until the puppies are 14 days old.
Deworming Pregnant Dogs and Cats
Parasites become active in late pregnancy when females are heavily pregnant and stressed. This is the time when moms can least resist parasites. Babies are born with sterile guts, and moms seed their guts with good bacteria to assist with digestion. However, she can also seed them with parasites. Roundworms, hookworms, whipworms, Coccidia, and Giardia can all be given to the puppy in the nursing period. Roundworms can be transmitted across the intestinal wall and into the puppies via the placenta.
As the parasites take in the mother's nutrition, they'll also take in the dewormer – meaning we can kill them effectively. Mom may be the source of these parasites, but the parasites can be controlled. Fenbendazole is labeled for pregnant moms. It not only gets the worms, but it also kills Giardia. By cleaning up the mother in late pregnancy and early lactation, you can also solve the parasite issues for your puppies later!
Newly Acquired Animals
No matter what the history or age, assume they have parasites! Deworm immediately, repeat in two weeks and start on the above adult program.
Parasites do not want to kill your pets; they want to use them as a dinner plate! Your job is to manage the parasites to prevent that from happening.
For a helpful worming guide, read the Worming Schedule.
If you need help, call us at 800.786.4751.
Donald Bramlage, Doctor of Veterinary Medicine, Former Director of Veterinary Services at Revival Animal Health
Donald Bramlage, Doctor of Veterinary Medicine, practiced veterinary medicine for 30+ years and is known for his work in managing parvovirus. He received his Doctor of Veterinary Medicine from Kansas State University in 1985. He served as Revival's Director of Veterinary Services from 2011 until his retirement in 2019.