Cat · Sweden

Kittens are not puppies.

SVA’s cat roundworm page, last reviewed 20 May 2026, is the Swedish timing. It does not replace the broader “about 3 weeks” line, and it is not a calendar to run at home.

When a kitten is first treated

The broader evidence line is milk-borne roundworm, with treatment from about 3 weeks even if the first faecal is negative. Beside that, not instead of it, SVA says: “Kattungar kan avmaskas första gången när de är fyra till sex veckor gamla (alltså senare än hundvalpar där smitta kan föras över till foster).” The worm reaches kittens through the milk and not before birth. Your vet sets the plan.

Indoors, outdoors, hunting

The same SVA page says strictly indoor cats are not infected with roundworm, and it cites a Swedish study from 2015 in which about 20 percent of outdoor cats had roundworm. Outdoor cats that hunt are a different conversation from an indoor adult. For a hunter or a raw-fed cat, the evidence brief records regular roundworm and tapeworm control plus fleas, because Dipylidium uses the flea. This page names no product.

An indoor adult: test, don’t automate. If toddlers, raw offal or an immunosuppressed person share the home, the vet may test more often. ESCCAP’s 11 June 2025 notice describes risk-based plans. The guideline file did not open, so no treatment frequency is quoted from it.

Heartworm, where it is transmitted

Feline heartworm: few worms, sudden death in a substantial minority of diagnosed cases, and melarsomine is fatal to cats, so prevention is the only practical path where transmission exists. A topical combination was 100 percent preventive in two induced-infection studies. That is efficacy, not lifespan. It is not the default for a cat that stays in Sweden. Montoya and colleagues report life expectancy at birth for cats of 11.18 years. That paper does not mention parasites.

Do not

No dose in milligrams.
Do not put a dog permethrin spot-on on a cat.
Do not give a cat a horse wormer.
Pumpkin seed, herbs and diatomaceous earth are not equivalent worm control. Essential oils and concentrated garlic can harm cats.

Grades and the 6 October 2026 link check

Ask your vet.

Sources cited here

SVA, spolmask hos kattOpened 6 October 2026. Last reviewed 20 May 2026. Kittens at four to six weeks, and about 20 percent of outdoor cats in a Swedish study from 2015.
CAPC heartwormDirect GET returned 403. A later fetch opened the page. “Heartworm for Dog. Last updated: Jan 14, 2026.” That date is before the review cutoff.
Feline topical heartworm preventionOpened 6 October 2026. The title matches the feline topical heartworm-prevention paper. Efficacy, not lifespan.