Cat Bites - Dangers and Disease

Myth: You can't get a disease from a bite from your own cat.

Fact: Anyone can get an infection from any cat bite.

Cats carry a germ called Pasteurella multocida in their mouths, a bacterium that can cause severe infections in humans. Both humans and animals have a mouthful of germs, but normally the body's own immune system keeps them in their place. The skin is one of the most important natural barriers. When this is disrupted by a bite, especially a puncture wound, bacteria are introduced into the deeper tissues, where they are nourished by a constant supply of blood. Cat teeth are often sharp and needle-like, and may penetrate to underlying tendons and ligaments, where infection can endanger the use of the effected limb.

Any cat bite should be cleaned immediately with soapy water and rinsed for several minutes. Even with thorough cleansing, infection is likely. However, taking antibiotics before signs of infection develop does not seem to decrease the likelihood of a wound becoming infected.

Infections from cat bites spread quickly, especially when the bite wound is on the hand. Within hours redness, swelling, pain, and warmth may develop at the site of the wound. A red streak may extend upwards as inflammation spreads along the lymphatic channels and veins that lead away from the wound. If these symptoms occur, call your doctor right away. He may decide to offer you an antibiotic over the phone, or more likely will want to see you. Either way, you will need an antibiotic. Penicillin or amoxicillin left over from a sore throat or ear infection is not likely to be effective. If you decide to wait a few days and see how things develop, you're likely to end up in the hospital on intravenous antibiotics.

Cats carry other diseases as well. Cat scratch disease is caused by Bartonella henselae. Infection with this organism produces a crusted, red bump or pustule at the site of the cat scratch or bite within 3 to 10 days of exposure. Swollen glands develop within the next 2 weeks. Bites on the arm or hand produce swollen glands in the armpits, whereas those on the lower extremities cause lymph nodes in the groin to swell. Along with the swollen glands comes fever, fatigue, loss of appetite, and headache. In general, no antibiotics are needed for this infection, which takes 2 to 5 months to resolve.

Contracting rabies from an unvaccinated cat is a possibility. In the US, the highest incidence of cat rabies is clustered in the lower New England states. If your own cat bites you but has been vaccinated, the risk is practically nonexistent. If a ferrel cat bites you, you should contact your doctor or health department right away to see if you are a candidate for rabies immunization. If you wait until you have symptoms, you'll be dead soon. Don't skimp on immunizing your pet - spending $20 now could save you $2,000 or more in the long run.

Copyright 2010 Cynthia J. Koelker, M.D.

Household Dangers from Kittens

Kittens and children are a lot less compatible than you would think. Most pregnant women are aware of the risks associated with cat feces during pregnancy, which in a worst-case scenario can lead to such severe complications as cerebral palsy in the unborn child. This awareness of the risks tends to relax, though, after the child has reached the toddler stage, to be replaced by a consciousness of the positive benefits to the child of keeping a pet.

Those who have lived with cats and especially kittens will know how common it is to be scratched and bitten by a playful pet. Most owners will minimize the risks, because in their experience nothing bad has ever come of a cat scratch. However, if people are better informed of the risks, they would not necessarily take these injuries so lightly. More than half all cat bites result in infection of some kind, most commonly from the Pasteurella multocida bacteria, which form part of the normal flora of cats.

A local infection, at the site of the wound only, can lead to swelling or the formation of puss. This in itself is not always dangerous, but may lead to complications, perhaps with the joints becoming infected, or even the whole lymphatic system being invaded. Clearly those more at risk to such forms of infection are the very young, the elderly or those with suppressed immunosufficiency, such as cancer patients on medication and AIDS sufferers.

Cat scratch disease is an infectious illness associated with cat scratches, bites, or exposure to cat saliva. The bacteria Afipia felis and Bartonella henselae do not necessarily provoke symptoms in the carrier cat. But complications arising from infections with these bacteria can lead to nasty complications in humans, not just locally where the skin has been torn. CSD is perhaps the most common cause of chronic lymph node swelling in children, a feverous infection lasting up to two months.

Children under nine years of age are especially vulnerable to scratches and bites in the face and neck regions, most especially from kittens, which happen to be the most likely carriers of the Bartonella henselae group of organisms. Thus the advice is not to let children play too roughly with kittens - and any scratches or bites should be washed immediately with soap and warm water.

Osteomyelitis or septic arthritis from cat bites is not uncommon. The synovial capsules of the joints are usually completely sterile and infection at these points is both extremely painful and potentially very harmful. Osteomyelitis and septic arthritis can affect any joint or bone, but most commonly involve the lower limbs. Both are most commonly caused by Staphylococcus aureus and require urgent treatment. The initial symptoms are tenderness and an unwillingness to use the joint or limb in question. Swelling and redness do not necessarily appear straight away.

Some authorities claim that fleas carry B. henselae bacteria, but the evidence is not conclusive. Nevertheless, it makes sense to keep fleas in check to guard against unnecessary risks. Cats should never be allowed to lick any wounds you or your child may have, as the saliva is where the bacteria come from.

If you or your child are bitten or scratched by a cat, at the first signs of any symptoms such as swelling, pustules, fatigue, fever, headache or swollen glands, consult your physician.