The health of domestic cats is a well studied area in veterinary medicine.
Topics include infectious and genetic diseases, diet and nutrition and non-therapeutic surgical procedures such as neutering and declawing.
See also: List of feline diseases.
An infectious disease is caused by the presence of pathogenic organisms such as viruses, bacteria, fungi, or parasites (either animalian or protozoan). Most of these diseases can spread from cat to cat via airborne pathogens or through direct or indirect contact, while others require a vector such as a tick or mosquito. Certain infectious diseases are a concern from a public health standpoint because they are a Feline zoonosis and transmittable to humans.
Viral diseases in cats can be serious, especially in catteries and kennels. Timely vaccination can reduce the risk and severity of an infection. The most commonly recommended viruses to vaccinate cats against are:
Viruses for which there are no vaccines:
See: Global spread of H5N1#Felidae (cats)
Veterinary parasitology studies both external and internal parasites in animals. External parasites, such as fleas, mites, ticks and mosquitoes can cause skin irritation, and are also often carriers of other diseases or of internal parasites.
Domestic cats are affected by over 250 naturally occurring hereditary disorders, many of which are similar to those in humans, such as diabetes, hemophilia and Tay–Sachs disease.[2] [4] For example, Abyssinian cat's pedigree contains a genetic mutation that causes retinitis pigmentosa, which also affects humans.[2]
Skin disorders are among the most common health problems in cats and have many causes. The condition of a cat's skin and coat can be an important indicator of its general health.
Researchers at the University of Cornell Feline Health Center believe that "most zoonotic diseases pose minimal threat" to humans. However some humans are particularly at risk. These are people "with immature or weakened immune systems" (infants, the elderly, people undergoing cancer therapy, and individuals with acquired immunodeficiency syndrome).
Some common and preventable forms of zoonosis[6] are as follows:
See main article: Feline vaccination. Vaccinations are an important preventive animal health measure. The specific vaccinations recommended for cats varies depending on geographic location, environment, travel history, and the activities the animal frequently engages in. In the United States, regardless of any of these factors, it is usually highly recommended that cats be vaccinated against rabies, feline herpesvirus 1 (FHV-1), feline calicivirus (FCV), and feline panleukopenia virus (FPV). The decision on whether to vaccinate against other diseases should be made between an owner and a veterinarian, taking into account factors specific to the cat.
Feline diseases such as FeLV, FIV, and feline heartworm can be detected during a routine visit to a veterinarian. A variety of tests exist that can detect feline illnesses, and with early detection most diseases can be managed effectively.
Once-a-month topical products or ingestible pills are the most commonly used products to kill and prevent future parasite infestations.
See also: Pet food. Veterinarians commonly recommend commercial cat foods that are formulated to address the specific nutritional requirements of cats, although an increasing number of owners are opting for home-prepared cooked or raw diets.
Although cats are obligate carnivores, vegetarian and vegan cat food are preferred by owners uncomfortable with feeding animal products to their pets. The U.S. Food and Drug Administration Center for Veterinary Medicine has come out against vegetarian cat and dog food for health reasons. Cats require high levels of taurine in their diet. Taurine is an organic acid found in animal tissues. It is a major constituent of bile and can be found in the large intestine. Taurine has many biological roles, such as conjugation of bile acids, antioxidation, membrane stabilization, and modulation of calcium signaling. It is essential for cardiovascular function in cats, as well as the development and function of skeletal muscle, the retinas, and the central nervous system. Although meat protein can be substituted with vegetable proteins, vegetable proteins do not provide a sufficiency of the specific amino acids which are vital for a cat's body to function.[7] [8]
Cats can be selective eaters. Although it is extremely rare for a cat to deliberately starve itself to the point of injury, in obese cats, the sudden loss of weight can cause a fatal condition called feline hepatic lipidosis, a liver dysfunction which causes pathological loss of appetite and reinforces the starvation, which can lead to death within as little as 48 hours.
Pica is a condition in which animals chew or eat unusual things such as fabric, plastic or wool. In cats, this can be fatal or require surgical removal if a large amount of foreign material is ingested (for example, an entire sock). It tends to occur more often in Burmese, Oriental, and Siamese breeds.
See main article: Allergies in cats. Food allergy is a non-seasonal disease with skin and/or gastrointestinal disorders. The main complaint is pruritus. The exact prevalence of food allergy in cats remains unknown. There is no breed, sex or age predilection, although some breeds are commonly affected. Before the onset of clinical signs, the animals have been fed the offending food components for at least two years, although some animals are less than a year old. In 20 to 30% of the cases, cats have concurrent allergic diseases (atopy / flea-allergic dermatitis). A reliable diagnosis can only be made with an elimination diet. Challenge–dechallenge–rechallenge is necessary for the identification of the causative food component(s). Therapy consists of avoiding the offending food component(s).[9] Cats with food allergies may present with red, hairless, and scabby skin. Hair loss usually occurs on the face and/or anus. Depending on the severity of the reaction, it may take two weeks to three months for a cat to recover once the offending allergen is removed.
A number of common human foods and household ingestibles are toxic to cats, including chocolate solids, onion, garlic, avocados, grapes, raisins, coffee, tomato and tomato leaves, and milk.
Phenolic compounds such as those in TCP are harmful to cats.[10]
Malnutrition in cats is currently uncommon due to complete and balanced diets being formulated and fed.[11] Yet it can still occur if the cat's food intake decreases beyond what the food can provide, if interactions occur between ingredients or nutrients, if mistakes are made during formulation or manufacturing, and if the food is stored for a lengthy amount of time. If a cat becomes malnourished, a deficiency of energy, protein, taurine, essential fatty acids, minerals (calcium, phosphorus, magnesium, sodium, potassium), vitamins (A, D, E, thiamine, niacin, biotin), and trace elements (iron, copper, zinc, iodine, selenium) can occur, causing a multitude of deficiency symptoms.[12]
For information about a correct cat diet, see Cat food.
One of the cat diseases caused by malnutrition is central retinal deficiency, a dysfunction in cats that can be hereditary as well.[13]
The retina, a thin layer of tissue in the back of the eye, is the structure affected by this disorder. This structure receives the light gathered and focused from the lens.[14] It essentially takes light and converts it into electrical nerve signals that the brain interprets as vision. The retina contains rods and cones, which are photo-receptors that help the animal see (rods) and visualize certain colors (cones).
Retinal degeneration can be caused by a taurine deficiency, which is why many cat foods are supplemented with taurine.[15] [16] Central retinal deficiency is irreversible, but its effects can be significantly hindered if a diet supplemented with adequate amounts of taurine is provided. Vitamin deficiencies in A and E can also lead to retinal degeneration in cats.
See also: Obesity in pets. Neutering and overfeeding have contributed to increased obesity in domestic cats, especially in developed countries. Obesity in cats has similar effects as in humans, and will increase the risk of heart disease, diabetes mellitus, etc., thereby shortening the cat's lifespan.
The ASPCA lists some common sources of toxins[17] that pets encounter, including: plants,[18] human medications and cosmetics,[19] cleaning products,[20] and even foods.[21]
Some houseplants are harmful to cats. For example, the leaves of the Easter Lily can cause permanent and life-threatening kidney damage to cats, and Philodendron are also poisonous to cats. The Cat Fanciers' Association has a full list of plants harmful to cats.[22]
Paracetamol or acetaminophen (trade name Panadol and Tylenol) is extremely toxic to cats, and should not be given to them under any circumstances. Cats lack the necessary glucuronyl transferase enzymes to safely break paracetamol down and minute portions of a normal tablet for humans may prove fatal.[23] Initial symptoms include vomiting, salivation and discolouration of the tongue and gums. After around two days, liver damage is evident, typically giving rise to jaundice. Unlike an overdose in humans, it is rarely liver damage that is the cause of death; instead, methaemoglobin formation and the production of Heinz bodies in red blood cells inhibit oxygen transport by the blood, causing asphyxiation. Effective treatment is occasionally possible for small doses, but must be extremely rapid.
Even aspirin, which is sometimes used to treat arthritis in cats, can be toxic and must be administered cautiously. Similarly, application of minoxidil (Rogaine) to the skin of cats, either accidentally or by well-meaning owners attempting to counter loss of fur, has sometimes proved fatal.[24] [25]
In addition to such obvious dangers as insecticides and weed killers, other common household substances that should be used with caution in areas where cats may be exposed include mothballs and other naphthalene products, as well as phenol-based products often used for cleaning and disinfecting near cats' feeding areas or litter boxes, such as Pine-Sol, Dettol (Lysol), hexachlorophene, etc. which, although they are widely used without problem, have been sometimes seen to be fatal.[26] Essential oils are toxic to cats and there have been reported cases of serious illnesses caused by tea tree oil and tea tree oil-based flea treatments and shampoos.[27] [28] [29]
Many human foods are somewhat toxic to cats; theobromine in chocolate can cause theobromine poisoning, for instance, although few cats will eat chocolate. Toxicity in cats ingesting relatively large amounts of onions or garlic has also been reported.
Cats may be poisoned by many chemicals usually considered safe by their human guardians, because their livers are less effective at some forms of detoxification.[30] [31] Some of the most common causes of poisoning in cats are antifreeze and rodent baits.[32] Cats may be particularly sensitive to environmental pollutants.[33]
Cats can succumb quickly from ethylene glycol poisoning, after ingesting as little as one teaspoon. The primary source of ethylene glycol is automotive antifreeze or radiator coolant, where concentrations are high. Other sources of antifreeze include windshield deicing agents, brake fluid, motor oil, developing solutions for hobby photographers, wood stains, solvents, and paints. Some people put antifreeze into their cabin's toilet to prevent it from freezing during the winter, resulting in toxicities when animals drink from the toilet. Small amounts of antifreeze may be contained in ornaments such as snow globes. A cat suspected of having ingested ethylene glycol requires immediate veterinary treatment, to receive an antidote within three hours. The earlier the treatment is started, the greater the chance of survival.