Heartworm disease affects dogs most frequently. Cats suffer from heartworm disease less often but are still at risk. Heartworms have been found in people in rare cases.
Causes are listed in order from most common to least common. In dogs and cats, ear problems are by far the most common cause of head shaking.
Fleas can infest dogs, cats, rodents, and other mammals. People can be bitten by fleas as well.
Fleas are a parasitic pest of dogs, cats, and other animals. They are blood sucking insects. Minor flea infestations can lead to severe skin and health problems in dogs and cats. Major infestations can be life-threatening.
Cats and dogs of any age.
Ear infections are common and painful problems for pets. In cats and dogs, ear infections typically are opportunistic and not contagious. They often occur when the ear’s immune system is disrupted by allergies, moisture, poor air circulation, or diseases such as feline AIDS. Under these conditions, bacteria and yeast that normally live harmlessly in the ear are able to proliferate to the point of infection.
Diarrhea is an extremely common problem in both cats and dogs. Mild, transient diarrhea rarely is a cause for concern. Severe or chronic diarrhea is often caused by major medical conditions, and can be damaging to a pet’s health in its own right.
More common causes are listed first. Less common causes are listed later.
Adult cats and dogs
Dental disease is by far the most common major health problem of cats and dogs. Despite its name, dental disease does not merely affect the teeth and mouth. Dental disease impacts the entire body, with serious consequences for health, longevity, and well-being.
More common causes are listed first; less common causes are listed later.