All skin parasites usually cause itchy skin and depending on the type and number of parasites involved this can range from an occasional scratch to devastating self-mutilation. Other signs can be bald patches, red patches, spots, scaly skin, crusts and sore patches which are prone to secondary infection with bacteria. This aggravates the situation, causes more itching and soreness and making diagnosis more difficult. Some animals can become generally unwell.
Sometimes there is a typical pattern of itching related to a particular parasite, but usually further tests are necessary to determine the cause. Ticks are an exception – they are very obvious once they have filled with blood.
Fleas are the most common skin parasites found on cats and almost every cat which is allowed to go outside will get fleas at some point during his or her lifetime. Adult fleas live on the cat and feed on blood, and each female flea can lay up to 50 eggs per day. These eggs are oval and creamy white and fall off the cat into the environment where they develop through 3 life stages and then hatch as an adult flea. It is very important to remember this when treating a flea problem, and to use a household treatment, as this is where the majority of the flea population lives. There is one stage of development which is near-on impossible to kill, which is why it is so hard to get a “clean kill” and we have to persevere for a few months to eradicate the problem. Some animals with fleas are not bothered by them, but others can develop severe irritation, hair loss and inflamed or infected skin.Fleas are easily transmitted from cat to cat or from other animals (e.g. dogs, hedgehogs) to cats, but even more commonly, fleas are picked up from environment, e.g. a house, shed or car where developing fleas are lying in wait. Fleas can also be carried by humans who handle cats, even if the human carrier is not subjected to bites. Humans can get bitten by cat fleas, but treating the cat should be sufficient to prevent this, as the cat is the preferred host.
Treatment: it is best to prevent a flea problem, but if you get a problem, treat it thoroughly as soon as it is noticed. Use a good quality spot-on preparation and also treat the environment (house, shed, car etc) - this is very important. The treatment of all pets should be continued over a period of at least 3 months to ensure all the next flea generations have gone. Pet-shop flea collars, shampoos and powders are not recommended – many of these are actually “flea repellents” and do not kill the flea, and some of the treatments are potentially toxic for your cat if misused or if your cat chews on them. It is important to note that some dog preparations which are perfectly safe in dogs are very dangerous when they are used on cats, and can cause severe or fatal toxic reactions.
In rare cases cats can be affected by the rabbit ‘sticktight’ flea (Spilopsyllus cuniculi), a parasite usually affecting rabbits ears. This flea causes skin lesions on the ear flap (pinna). It lives and feeds in only one place on the skin and does not usually move away when the ears are examined. Only cats who are in contact with wild rabbits, e.g. cats who hunt them, will be affected.
Several types of tick are found in the UK. Usually they only cause local irritation/infections. However, in some parts of the UK ticks can transmit more serious infectious diseases e.g. Lyme’s disease, and in other countries they commonly transmit a variety of unpleasant infections such as babesiosis. Ticks burrow their mouthparts into the skin, fill their bodies with the cat’s blood and then drop off after a few days. Ticks are a problem from spring to autumn, and especially in late spring and early autumn. Only cats that spend time outside will be affected by ticks. Ticks are found on trees, bushes and in areas of denser vegetation and in the UK where there are wild deer, and they are able to sense when a cat or other animal passes by. They crawl onto the cat and start sucking blood. Ticks are not transmitted from cats to other animals or human beings. Ticks should be removed individually with a tick remover, taking care that the mouthparts are removed in order to avoid causing a nasty skin reaction. All other procedures such as covering the tick in oil, alcohol or glue should never be used because this can leave the tick dying slowly in the skin, and infectious agents can be pumped back out from the tick into the pet. There is a good spot-on which works against ticks, and there is a very effective flea and tick collar which prevents the tick from attaching, so if your cat is prone to these pests, please contact us for advice. Most products in use for dogs are again very toxic for cats, so special products against ticks have to be used for cats. Ticks and harvest mites can affect humans as well as animals. They are not transmitted by cats, but humans will pick them up from the environment in the same way as cats do.
Mites come in different shapes and sizes. They affect cats less commonly than dogs, again probably because cats groom themselves much more thoroughly.
The Sarcoptes mite or ‘fox mite’ causes scabies, which is a very itchy and uncomfortable skin disease. It is common in dogs and only rarely affects cats. Foxes can also be affected by scabies. The mites burrow tunnels through the skin where they live and lay their eggs. Because they actually live inside the skin, they cannot be seen on the outside and brushing and bathing will not remove them. In the early stages of the disease many cats are not itchy, so the problem may not always be immediately apparent to the owner. Later, however, the discomfort becomes extreme. Sarcoptes mites are often transmitted by direct contact. The mites spend their entire life-cycle on affected cats but they can survive for up to 3 weeks away from their host and so cats can be infected even without coming in direct contact with an affected animal.
The Notoedric mange mite is another rare parasite in cats in the UK. It usually affects the head and especially the ears. Notoedres infections are occasionally mistaken for scabies, and infections with this mite are intensely itchy. Hair loss and sore skin are obvious signs of the disease. Later the skin typically becomes covered with greyish scales and crusts. These mites can also affect rabbits and, very rarely, dogs.
Cats affected by Cheyletiella mites are most commonly long-haired. Dogs and rabbits can also be affected. The mites live on the surface of the skin and usually spend their entire life on the animal but adult mites can live in the environment for 10 to 14 days.
Affected animals are often have scabby skin, and although most cats have only mild or no itchiness, occasionally severe discomfort develops. Sometimes mites can be seen on the hair (‘walking dandruff’).
Sarcoptes, Notoedres and Cheyletiella mites frequently pass from infected pets to their owners and cause intensely itchy red spots and crusts on human skin. However, after treating the mites on the cat, disease in humans is usually self-limiting and does not require additional treatment.
Demodex is a special type of mite which is probably only transmitted during the first hours of life from mother to newborn kittens. It is present in small numbers in the majority of normal cats and usually does not cause any clinical signs. Occasionally, localised scabby itchy spots can appear or cats can develop mild ear infections due to demodex mites. In rare cases the mites can spread over the whole body of affected cats and cause generalised problems. This is almost always a sign of a significant underlying disease which has reduced the function of the immune system – a normal immune system would keep the mites in check. Although a generalised Demodex infection usually causes less severe skin disease in cats than in dogs, the prognosis is always guarded and further diagnostic tests are necessary to identify any underlying disease process. The treatment of generalised cases can be difficult and frustrating. Animals affected by Demodex are often not as itchy as may be expected with other types of mite infestation. The Demodex mite is not transmitted from cats to humans, although humans have their own version of demodex infection.
Harvest mites are generally only a problem in summer and early autumn. Mite larvae are found mainly on the feet (especially between the toes), but also on the legs, occasionally the head/ears and the tummy of affected cats. They feed for several days and then leave the animal. Infested cats can show signs ranging from no symptoms at all to intense itching. Larvae are often visible as small orange/red patches on the skin. Itchiness may persist for a while after the mites have gone.
Harvest mites most commonly live in areas of well-drained ground with heavy vegetation, so the larvae will infest cats that frequent such areas. Even though the individual larvae do not stay long on the cat, it is possible for cats to be infested on a regular basis when they often go to the areas where the mites are found.
Infestation with lice is actually rare in cats. Cats have different lice from humans and they cannot be transmitted to humans, and human lice will not live on cats. The entire life-cycle of lice is completed on the cat within 3 weeks. Signs range from no symptoms at all to severe skin disease, with the empty egg cases (nits) attached to the hairs as the giveaway sign.
Most affected animals are presented with a dry scruffy looking coat, some hair loss and varying degrees of itchiness. Lice are transmitted by direct contact or by grooming a cat with a contaminated brush or comb. Louse infestations are more common when many cats are together in a relatively small space, such as a cattery, a rescue centre or even at a cat show. Lice can be treated with most of the spot-on preparations that are used to treat or prevent fleas. Treatment of the environment is not necessary, although grooming equipment (combs, brushes etc.) should be thoroughly cleaned.