Common Cat Diseases, from ASPCA

As a cat parent, it is important to recognize the signs and symptoms of common illnesses so you can seek veterinary help for your feline friend in a timely manner if necessary. Read on for information about diseases and other medical inflictions that frequently impact cats.

CancerCancer is a class of diseases in which cells grow uncontrollably, invade surrounding tissue and may spread to other areas of the body. As with people, cats can get various kinds of cancer. The disease can be localized (confined to one area, like a tumor) or generalized (spread throughout the body).

Diabetes
Diabetes in cats is a complex disease caused by either a lack of the hormone insulin or an inadequate response to insulin. After a cat eats, her digestive system breaks food into various components, including glucose—which is carried into her cells by insulin. When a cat does not produce insulin or cannot utilize it normally, her blood sugar levels elevate. The result is hyperglycemia, which, if left untreated, can cause many complicated health problems for a cat.

Feline Immunodeficiency Virus (FIV)
Cats infected with feline immunodeficiency virus (FIV) may not show symptoms until years after the initial infection occurred. Although the virus is slow-acting, a cat’s immune system is severely weakened once the disease takes hold. This makes the cat susceptible to various secondary infections. Infected cats receiving supportive medical care and kept in a stress-free, indoor environment can live relatively comfortable lives for months to years before the disease reaches its chronic stages.

Feline Leukemia Virus (FelV)
First discovered in the 1960s, feline leukemia virus is a transmittable RNA retrovirus that can severely inhibit a cat’s immune system. It is one of the most commonly diagnosed causes of disease and death in domestic cats. Because the virus doesn’t always manifest symptoms right away, any new cat entering a household—and any sick cat—should be tested for FeLV.

Heartworm
Spread by infected mosquitoes, heartworm is increasingly being recognized as an underlying cause of health problems in domestic cats. Cats are an atypical host for heartworms. Despite its name, heartworm primarily causes lung disease in cats. It is an important concern for any cat owner living in areas densely populated by mosquitoes, and prevention should be discussed with a veterinarian.

High-Rise Syndrome
Many pet parents eagerly open their windows to enjoy the weather during the summer months. Unfortunately, unscreened windows pose a real danger to cats, who fall out of them so often that the veterinary profession has a name for the complaint—High-Rise Syndrome. Falls can result in shattered jaws, punctured lungs, broken limbs and pelvises—and even death.

Rabies
Rabies is a viral disease that affects the brain and spinal cord of all mammals, including cats, dogs and humans. This preventable disease has been reported in every state except Hawaii. There’s good reason that the very word “rabies” evokes fear in people—once symptoms appear, rabies is close to 100% fatal.

Ringworm
Although the name suggests otherwise, ringworm isn’t caused by a worm at all—but a fungus that can infect the skin, hair and nails. Not uncommon in cats, this highly contagious disease can lead to patchy, circular areas of hair loss with central red rings. Also known as dermatophytosis, ringworm often spreads to other pets in the household—and to humans, too.

Upper Respiratory Infections
A cat’s upper respiratory tract—the nose, throat and sinus area—is susceptible to infections caused by a variety of viruses and bacteria.

Worms
Cats can acquire a variety of intestinal parasites, including some that are commonly referred to as “worms.” Infestations of intestinal worms can cause a variety of symptoms. Sometimes cats demonstrate few to no outward signs of infection, and the infestation can go undetected despite being a potentially serious health problem. Some feline parasitic worms are hazards for human health as well.

Common Types of Worms in Cats
Outdoor cats and those who are routinely exposed to soil where other animals defecate are prone to worms. Kittens and cats who do not receive regular preventative health care are most at risk for developing complications associated with internal parasites.

• Roundworms are the most common internal parasites in cats. Resembling spaghetti, adult worms are three to four inches long. There are several ways cats can become infected. Nursing kittens can get roundworms from an infected mother’s milk, while adult cats can acquire them by ingesting eggs from the feces of an infected cat.
• Hookworms are much smaller than roundworms—less than an inch long—and reside primarily in the small intestine. Because they feed on an animal’s blood, hookworms can cause life-threatening anemia, especially in kittens. Hookworm eggs are passed in the stool and hatch into larvae, and a cat can become infected either through ingestion or skin contact.  
• Tapeworms are long, flat, segmented parasites that range from 4 to 28 inches in length. An infestation can cause vomiting or weight loss. Cats acquire tapeworms by ingesting an intermediate host, like an infected flea or rodent. When cats are infected, tapeworm segments—actual pieces of the worm that resemble grains of rice—can often be seen on the fur around a cat’s hind end.
• Lungworms reside in the lungs of a cat. Most cats will not show any signs of having lungworms, but some can develop a cough. Snails and slugs are popular intermediate hosts of this type of parasite, but cats are usually infected after eating a bird or rodent who has ingested an intermediate host.
• Though means of transmission can vary, one of the main ways that cats get worms is through the ingestion of the feces of infected felines. Mother cats can also pass on worms to their kittens.

Worm Prevention

• Keep your cat indoors to avoid exposure to infected cats, rodents, fleas and feces.
• Make sure your home, yard and pets are flea-free.
• Practice good hygiene and wear gloves when changing cat litter or handling feces. It’s also important to frequently dispose of stool.
• Ask your veterinarian to recommend an appropriate internal parasite treatment or prevention program for your cat.

Symptoms of Worms in Cats
Symptoms differ depending on the type of parasite and the location of infection, but some common clinical signs include:

• Diarrhea
• Worms visible in stool or segments of worm seen near anus
• Bloody stool
• Bloating or round, potbellied appearance to abdomen
• Weight loss
• Vomiting
• Constipation
• Anemia
• Coughing
• Trouble breathing

If you think your cat may have worms, it’s important to bring her to a veterinarian, who can confirm the presence of worms. Avoid self-diagnosis, since worms are not always visible or identifiable.
Treatment for Worms
Please don’t attempt to treat your pet yourself—your cat should be treated for the specific type of worms he has.

• Not all dewormers eradicate all types of worms.  Your veterinarian will determine the type of worm(s) infestation(s) your cat has, and prescribe the best course of treatment.  Your veterinarian will also be able to tell you if the dewormer should be repeated, and when.
• Not all dog medications are safe for cats.
• Some over-the-counter deworming medications can be harmful if used inappropriately.

Transmission of Worms from Cats to Humans
A large number of roundworm eggs can accumulate where cats defecate. People, especially children, who ingest such eggs can develop serious health problems, such as blindness, encephalitis and other organ damage. Treatment of blindness caused by roundworm may involve surgical removal.
Hookworm larvae can penetrate human skin and cause lesions. People can acquire tapeworms through the ingestion of an infected flea, although this is rare.