Worms and Fleas

Worms

Dogs and cats of all ages are vulnerable to both roundworms and tapeworms. In many cases infection is not obvious, but vomiting and diarrhoea, abdominal discomfort, stunted growth and poor coat condition can occur, especially in puppies and kittens. Infections are similar in these species; the following notes are colour coded for dogs, cats or both species.

Roundworms
Toxocara canis is the most important roundworm affecting dogs in the UK.

Toxocara cati affects cats.

Almost all puppies are infected with Toxocara before birth (across the placenta) or via the mother’s milk. Therefore many unweaned puppies have mature, egg producing roundworms in their intestine within 3 weeks of birth.

Kittens are rarely infected across the placenta, but can acquire eggs via milk.

Weaned pups/kittens and adult dogs/cats can be infected by ingestion of Toxocara eggs from soil or faeces. In animals under 6 months of age ingested eggs complete their lifecycle with 3-4 weeks, each adult Toxocara worm producing up to 20,000 eggs per day. These become infective within 3-4 weeks and can remain viable in soil for years. Older animals develop immunity, but worms still survive in a dormant state and eggs will still be produced from time to time.

Infection can also be acquired through eating mice/rats etc, more common in cats than dogs.

Adult worms be up to 18cm long and very numerous, filling the gut of badly affected animals.

Public Health Concerns – Toxocara is important both as a potential health risk for your dog or cat, but also because it can cause a rare but serious disorder, Toxocaral Visceral Larval Migrans in people, especially children. This condition results from the human ingestion of infective Toxocara eggs (from soil or faeces), and subsequent migration of larvae into tissues such as the heart, central nervous system and eye.

Tapeworms
A number of tapeworm species affect dogs and cats, the Taenia family being the most important.

Tapeworms are acquired by ingestion of fleas (intermediate hosts) during grooming.

Mice/rats can also be a source of infection for cats.

Tapeworms are flattened and can be up to 5 metres long. They attach to the gut wall using a doubled circular set of sharp teeth.

Worm Control Programs
An effective worming program must therefore have two aims:

  • The prevention of infective egg production into the environment
  • The elimination of worms from the adult dog or cat
  • Safe and effective control can be achieved using the following guidelines. Since puppies and kittens are the greatest source of eggs, worming is especially important up to six months of age.
  • To minimise trans-placental infection pregnant bitches should be wormed at day 42 of gestation and again at day 2 post-whelping. Both bitch and pups should then be wormed every 2 weeks until 12 weeks old.
  • Pregnant queens need not be wormed but fortnightly post-kittening worming is recommended as for dogs until 12 weeks old.
  • Any adult over 12 weeks should be wormed every 3 months, or possibly even more frequently if the pet is around children. Remember that it may not be obvious that your pet has worms, but they should still be treated.
  • Faeces should be cleared promptly, before any Toxocara eggs become infective (3 weeks).
  • Your dog should be prevented from defaecating in parks or play areas.
  • Children should always wash their hands after playing in soil.

Drontal worming tablets can be used at any age and kill roundworms and tapeworms in a single dose. Puppies and kittens usually find Panacur granules or suspension easier than a large tablet. These products kill roundworms only, but tapeworm control is not vital until 12 weeks of age. These products are available without an appointment or prescription once your pet is registered.

An injection or spot-on (Droncit) is available for adult cats but kills tapeworm only. Can be used in combination with Stronghold Spot-On (treat fleas and roundworm).

Fleas

Fleas are small, brown, wingless insects with flattened bodies. They are visible to the naked eye, being about the size of half a grain of rice. Fleas transfer from host to host by jumping with their powerful back legs. Ctenocephalides felis felis is the most common species on cats and dogs. Flea bites often cause scratching as flea saliva contains a variety of substances that can be irritating or allergenic. Signs of flea infestation vary greatly between individuals. Some cats and dogs carry a few fleas with no ill effects at all, most are itchy, while some develop allergies to flea saliva causing distressing irritation, scratching, hair loss and secondary skin infections. Fleas can also cause problems through blood loss (72 adult fleas can consume 1ml of blood per day) and the transfer of tapeworms. This species of flea will not live on people, although humans may occasionally get an itchy bite.

Spring and Autumn are the worst periods for fleas, although we see them all year round. Signs that your pet may have fleas:

  • Your pet may be scratching
  • You may see actual fleas on your pet or in the house
  • Your pet may develop spots, scabs and hair loss especially along its back
  • You may find flea dirt in your pet’s coat. Flea dirt is digested blood. It appears as black specks (the size of grains of salt) and if placed on a wet tissue will leave a red/brown stain.
  • You may find itchy red spots on your skin, especially around your ankles.

Flea Control Options
Prevention is always better than cure. Itchiness, hair loss and secondary infections as a result of fleas can be expensive and time-consuming to treat. Regular treatment with a preventative flea-control product should stop such problems ever arising.

Scenario 1 – No current flea problem, but preventative regime required.

Option 1 – Insecticidal Spot-On/Spray.
These products kill adult fleas within 24hrs, minimising time available for irritant bites and breaking the lifecycle by killing any new fleas that jump on board before they have a chance to breed and produce eggs. Alternative products include:

  • Frontline Spot-On, apply once per month for cats, once every 2 months for dogs.
  • Frontline spray, economical if several animals of varying sizes, apply every 2 months (cats) / 3 months (dogs). Non-aerosol spray.
  • Advocate Spot-On for dogs and cats. Fat soluble throughout body thus also effective against roundworms in the gut and ear mites. Apply monthly.

Option 2: Program
Program works as a contraceptive, sterilising the flea and therefore breaking the lifecycle. However, cats and dogs that go outside will meet other animals and acquire new fleas, which will not be killed. These fleas will become sterile but will potentially stay alive for up to 100 days biting your pet. Thus insecticidal spot-ons/sprays are usually the treatment of choice unless your pets never meet other animals (i.e. house-cats).

Program tablets are given once per month to dogs.

Program injection is available for cats , which lasts for 6 months, or Program suspension can be given every month in the food.

Scenario 2 – Active flea problem

Insecticidal Spot-On/Spray +/- treat house

Products as above.

Fleas will be killed within 24hrs and immediate skin irritation will stop. Ongoing use will clear the environmental challenge (fleas/larvae in carpets) by breaking the lifecycle as fleas will be killed before breeding.

In severe infestations or if causing other problems (animals very irritated/ people getting bitten), then the house should also be treated with Indorex Spray. Vacuum the house well, including under furniture/beds. Spray the whole house as directed on can, paying particular attention to safety instructions. Remove or cover fish tanks with cling-film for an hour, remove caged birds. Indorex continues to work for up to one year.

Please Note - These flea products are prescription medicines. They may only be purchased over the counter if your pet is otherwise well and has been checked over by a vet within the last 12 months.