What To Expect After Deworming A Cat? (4 Side Effects)

Deworming cats has become a common practice these days. Many veterinarians recommend it because they believe it helps prevent tapeworm infections.

Cats are often infected with tapeworms when they eat raw meat or other contaminated food.

Tapeworms live in the intestines of cats and dogs, where they can cause serious health problems. Deworming cats prevents them from becoming infected with tapeworm eggs.

Deworming a cat involves giving her a pill containing praziquantel, a drug that kills adult tapeworms.

The procedure usually takes less than 30 minutes. Afterwards, the animal should be kept under observation for several hours to ensure she does not experience any side effects.

The most common side effect is diarrhea; however, some animals may have vomiting, lethargy, and loss of appetite.

If your pet experiences any of these symptoms after deworming, contact your veterinarian immediately.

But, if you simply want to find out more about what to expect after you deworm your cat, then keep on reading!

The Type Of Deworming Drugs for Cats

Dewormers are registered or licensed veterinary medicines. They frequently contain active ingredients such as anthelmintics (drugs used to kill parasites) or antiparasitic drugs.

Some products also include vitamins and minerals.

Some dewormers come in liquid form, and others are available only as tablets or capsules.

Liquid dewormers are easier to administer. However, you must make sure the product contains praziquantel. Most liquid dewormers do.

How Does Deworming a Cat Work?

Deworming works by killing parasitic worms that reside in the intestinal tract of your cat. These worms feed on blood and tissue cells.

When they die, their bodies release toxins into the bloodstream that damage organs and tissues.

When a cat eats a worm, the parasite attaches itself to the lining of the intestine. It then releases its larvae into the small intestine.

Once inside, the larvae mature into adults. The adults grow large enough to mate. Their offspring then leave the body through the feces-depending on the type of worm.

Once outside, the eggs hatch into tiny motile segments called miracidia. Miracidia swim around until they find a suitable host, usually another cat or dog.

The cat swallows the egg, which hatches into a larva. This larva develops into an adult worm, such as tapeworms.

Tapeworms can survive for years without feeding. As long as they remain alive, they continue to produce eggs.

The eggs travel through the digestive system and eventually reach the environment. There, they attach themselves to the ground and wait for a new host.

Tapeworms can infect humans and other animals. In people, tapeworms cause gastrointestinal problems. In pets, they can lead to weight loss, liver disease, and even death.

Preventing Infections With Deworming Cats

If you want to keep your cat healthy, you need to control tapeworm infestations. Deworming cats will help prevent them from getting sick.

You can buy dewormer pills at your local pet store. You may also get them online. Your vet can tell you how much medicine to give your cat.

He or she will also recommend a type of dewormer that best suits your cat’s age and size.

If your cat becomes ill due to using one of the dewormers, don’t hesitate to contact your vet for further information, as he can help provide an alternative.

What Symptoms Can You Expect From Your Cat After Deworming?


When deworming your cat, you should monitor them constantly for a few days to see if they have any adverse reactions to taking the deworming tablets.

If your cat becomes sick soon after worming, the worming therapy is unlikely to have been absorbed into the cat’s system.

In some occasions cats may feel unwell for a temporary period, usually, for not more than 24 hours.

If their symptoms of illness last longer than that, be sure to consult your vet. Some of the more common symptoms include a sensitive stomach, decrease in appetite and increased salivation.

Upset Stomach

Because the drugs in the deworming tablets clean out the stomach, a lot of things may be going on in your cat’s stomach to get rid of all the worms and parasites.

Some cats may feel nauseous and because the drug is so strong, they may even vomit during the deworming process.

If your cat vomits within an hour of taking the medication, you should consult your veterinary clinic to be safe. This is because they may not have taken up the drug appropriately, or they may have an adverse reaction to the drug.

Excessive vomiting is also something to watch out for. If your cat is vomiting excessively, then they may become dehydrated and should be taken to the vet as soon as possible for fluid and electrolyte treatment.

In very rare cases, the cat may be allergic or intolerant to the drug itself, which may cause it to have an adverse reaction towards the drug.

Another stomach related issue cat’s may experience is diarrhea. Because the cat’s digestive tract is wanting to get rid of the unwanted worms, they may experience extreme diarrhea.

Commonly, worms are also found in the stools they pass in the days after the drug is administered. Usually, the presence of diarrhea will only last two to three days.

If their diarrhea persists, it is a good idea to take the cat to the vet and have them treated for it.

This treatment may include antifungal medicine or anti-inflammatory drugs to help with the pain and symptoms associated with an irritated bowel.

After a few days, once their stomach has settled, you need to repeat the deworming process.

If the cat exhibits signs of illness, make sure that they have enough water and keep a close eye on their condition to see that it does not worsen.

If their condition does worsen, take them to the vet and be sure to take along the deworming medication so that the vet knows how to treat the cat.

Decreased Appetite

Because of their intensity, deworming drugs cause an upset stomach as we have seen and this can result in an overall lack of appetite in your cat.

This indirect effect only lasts for a short while (a couple of days) and if their appetite does not improve, consult your vet.

You can feed your cat after deworming, but start off with a small portion of food to monitor any side effects or symptoms of the drugs.

If they vomit, then at least it would only be a small amount of food that they vomit out.

Try to avoid giving your cat raw meat and fish. These food items contain parasites and may make your cat ill again.

Increased Saliva

This is a fairly common side effect which may last up to three days after the deworming treatment. It is important to note the difference between drool and saliva from foaming at the mouth.

Foaming at the mouth is a sign of a more serious illness like the deadly rabies virus.

This is especially significant to watch out for if your cat has not yet been vaccinated against rabies or if you live in a developing country.

Worms In Feces

After deworming, you may find worms in your cat’s feces. However, detecting them may not always be that easy, depending on the worm infection your cat has.

If your cat is infected with roundworms, whipworms or hookworms, these types of parasites are killed via paralyzation.

These worms are also quite small and even microscopic, and so you may not be able to see them.

Tapeworms on the other hand are much larger and are killed by being broken up into smaller segments, which are noticeable in the feces.

If you find live worms in your cat’s feces, it is nothing to worry about, as they have been at least expelled from your cat’s intestines.

Additionally, you may come across dead worms in the feces.

How Long Do The Side Effects Last?

As mentioned, side effects should not last more than two to three days. If any of these symptoms persist, be sure to consult with your veterinarian and take note of any adverse side effects not mentioned here.

What Happens Next?


Depending on the type of worm infestation and the product used to deworm, as well as factors like your cat’s age and size, there may be additional deworming treatments required for your cat, after the initial deworming.

This is important to do as the eggs and larvae are unaffected by the deworming drugs.

Therefore, in some cases after a few days the worms may be clear, but depending on the worm and the dosage of the drug, there may be additional treatments required two to three weeks after the initial deworming.

Kittens are usually dewormed when they go for their vaccines to ensure that they remain unaffected by worms.

Furthermore, if you have a cat that is outside on a regular basis and likes to hunt prey like mice or birds, your cat may need further deworming.

Because cats clean themselves, they have been known to reinfect themselves with parasites and intestinal worms.

This is because they lick their anus and during the deworming stage-the eggs may still be present in the rectum which will get ingested again and allowed to grow in the intestines.

Again, this is why a few doses over a course of a few weeks is needed.

There are also other threats in terms of parasitic worms apart from roundworms and tapeworms.

A heartworm is a real threat to a cats’ health. These types of parasites are treated through prescription medication, which can be obtained from your vet.

They will prescribe the right dosage for your cat depending on its size and age.

It is a good idea to get a monthly prescription for heartworms as this will treat and control other intestinal parasites like tapeworm and roundworm, and then you will not have to deworm for both.

But how do you know how often you should deworm your cat or kitten-what is enough? What is too little?

Below is a basic deworming schedule for your cat, depending on the stage of their life.

Schedule For Deworming


For your younger cats and kittens, as soon as you adopt or find one, you should take them to the vet to be dewormed. This is especially important if you are unaware of its medical history.

Before they are eight weeks old, kittens should be dewormed every two weeks and thereafter, this can be tapered down to once a month until they reach the age of six months.

Once they are over 6 months in age, they can be dewormed every three months or so.

Adult Cats

As your cat ages, they should be dewormed at least four times a year (at the start of every season of the year). This makes sure that they are dewormed throughout the year.

However, if your cat is a prevalent hunter or proverbial alley cat, then they should be dewormed more regularly.

This is because they are more likely to come into contact with other animals that have worms, and they are more likely to contract parasites from consumption of raw flesh of mice, fish, and birds.

Pregnant And Nursing Cats

Cats that are pregnant should only be dewormed if the products are safe for them and the kittens. This should be checked with the vet.

Once the kittens are born, the cat should be dewormed. These cats should be wormed when the pregnancy is complete and again during nursing with the kittens’ first worming treatment.

Frequently Asked Questions

Does A Vet Have To Deworm The Cat?

No, it is easy enough to deworm the cat on your own using over the counter dewormers.

It is important to note that not all general dewormers treat every parasite that may be affecting your cat, so it may be useful to get prescribed deworming medicine from your vet to treat the cat accordingly.

Dewormers come in liquid or tablet form, and so the only tricky bit may be sneaking it into their food or milk that you give them.

Should I Clean My House And Furniture After Deworming The Cat?

It is advised to do a thorough clean on all surfaces in your house-in particular the ones that the cats spend the most time on.

This includes a steam clean of the furniture and bed spreads to make sure that all the worm eggs and larvae in particular are not present in the household.

How Will I Know If The Deworming Treatment Worked?

Unfortunately, one of the best ways to tell if the cat is fully dewormed, is to inspect its stool. The stool should be healthy, not loose and free from blood.

Additionally, your cat should be healthy and not exhibit any signs of lethargy or other illness as discussed above. Your cat should also be eating as much as they normally would.

If you see unhealthy eating habits or symptoms of illness, be sure to consult with your vet to ensure that the cat is all right and perhaps look at alternative options of treatment.

How Long Is A Cat’s Recovery Period After Deworming?

Usually, the cat should be up and running in a few days.

However, if the medication made your cat ill, the cat may take a bit longer to recover and may have to be on a restricted or low-intake diet for as long as three weeks.

Again, it is possible that you may need to give your cat several courses of deworming doses , so the recovery period from the initial dose may be extended.

Should I Bathe My Cat After It Has Been Dewormed?

It depends. It may not be entirely necessary or needed, especially where a kitten is concerned.

They should only be bathed after they have been vaccinated, as they may become ill otherwise.

In terms of adult cats, if you have given them an internal deworming agent, there is no harm in giving them a bath. However, there is no specific need to do so.

Final Thoughts

Deworming your cat can be a bit of a process and may cause your cat to become ill. However, deworming is essential to keep your cat strong and healthy and living its best life.

Having parasites in their intestinal tract can decrease their quality of life massively if left untreated for a long time.

Hopefully after reading this article, you feel more informed on what to expect after deworming your cat. So contact your vet today and get the best deworming option for your cat.

Learn More about your cat by reading our interesting articles about Cats Here.

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