Disease transmission from pet cats to people

Cats make great pets and add joy and love to human life irrespective of age and gender. They are wonderful companions; keep pests out, have quiet and independent disposition, require low maintenance and are easily housed and trained. Many studies have confirmed the roles of the companion animals in preventing as well as treating human cardiovascular ailments, depression and mental stress.

Spending time with a cat is an effective form of animal-assisted therapy and a good choice for patients with limited mobility. Cuddling with a therapy cat may reinforce a sense of self-worth. Despite the fact that the pet cat population in India dwindled during last two years from 3.6 million in 2022 by 0.8 million. Yet, in Kashmir the post Covid-19 sudden boom in cat ownership appears to continue.

Despite several positive effects, many infections (Zoonosis) are naturally transmitted or shared between vertebrates and man. Of 1407 human pathogens, 816 (58%) are zoonotic in nature. Thirteen percent (13%) of the total pathogens are either emerging or reemerging, and majority (75%) of them classified as zoonosis. India is among the countries with highest zoonotic burden, 2.4 billion cases of human disease and 2.2 million deaths occurring per year.

The mortality rate from these diseases may vary and can escalate up to one third of the patients (Capnocytophaga septicemia). People with compromised immune system are definitely at higher risk of getting infection. Pregnant women, fetuses, infants, elderly and patients having chronic diseases or AIDS/HIV, those on chemo- or radiation therapy, born with congenital immune deficiencies, and organ or bone marrow transplanted individuals are all more vulnerable. Children in general are more likely to engage in behaviours which increase their risk.

The injuries resulting from cat scratches and bites vary in severity. Statistics generated by the Anti-Rabies Clinic of SMHS, Srinagar indicates that the cat associated animal bites are on a steep rise and have reached one-third of the total cases last year. In addition to the chances of transmitting dreaded Rabies virus, majority (up to 80%) of these wounds develop bacterial infection, show protracted healing time and result in permanent scars. Many patients may face Post Traumatic Stress Disorder (PTSD) subsequently. Several persons exposed to animals and animal environments may also develop allergic reactions to animal proteins (allergens).

The feline zoonotic diseases include bacterial (Cat Scratch Disease, Pasturella, Salmonella, Capnocytophaga, Staphylococcus etc.), viral (Rabies, Cow pox etc.), protozoal (Cryptosporidiosis, Giardiasis, Toxoplasmosis etc.), fungal (Ring worm or Dermatophytosis etc.), and parasitic; both endo- (Ancylostoma, Toxocara, Lung fluke, Echinicocosis etc.), and ectoparasites (fleas, lice, ticks, scabies/mite infestation). Some disease-carrying arthropods (fleas and ticks) use cats as a vector, or carrier of the pathogenic organisms resulting in human infections like  Lyme disease, Tick-borne encephalitis, and Rocky Mountain Spotted Fever.

Several infections and infestations (Campylobacteriosis, Salmonellosis, Rabies, Ring worm, Scabies etc.) of zoonotic importance cause disease in the affected cats. However many more show no visible symptoms in cats but produce illness in people. Up to 90%, 80%, and 40% of the ‘apparently healthy cats’ may harbor infective organisms like Pasteurella, Staphylococcus, and CSD respectively. People who live in close association with cats are more prone to diseases, but others can also acquire them from their stools and the parasites that leave their bodies.

Disease producing agents that are normal residents of the cat skin (e.g., Staphylococcus including Methicilin resistant) are transmitted to humans via direct contact with their skin, fur, or fomites. Several others (Ring worm, Scabies, Mite, Cowpox etc.) originate from the lesions in affected cats. Organisms carried in saliva of carrier or ailing cats (Rabies) are transmitted through animal bites or while licking the already existing wounds. Pasturella and Captocynophaga bacteria; the normal residents of the mouth and respiratory tract in cats, get access to human body through aerosol route or even while kissing the animals.

Cats with gastrointestinal infections (Salmonella, Campylobacteriosis, etc.) and/or infestations (protozoa and helminthes) pass the bacteria, oocysts, parasitic eggs and larvae (cutaneous larval migrans) in their stool and humans get them from the faecal-oral route or the contaminated soil. CSD bacteria are also carried in the bodies of the cat fleas and get transmitted by flea bites.

‘Prevention is better than cure’ has become a fundamental principle of modern health care. There are a number of good hygiene and pet husbandry practices that can significantly reduce the risk of becoming sick. The following important measures need to be routinely practiced by every individual in all the families keeping pet cats:

► Procure the kittens of at least six weeks age from preferably any Animal Welfare Board of India (AWB) certified pet shop and train them while young for developing desired social and healthy behaviours. The species specific utensils, equipments and allied items should also be procured and placed properly on arrival of the kitten.

► The behaviours that include being licked, sharing food and/or kitchen utensils, kissing, and sleeping with a cat must be avoided.

► Regular in-health veterinary care like deworming and ectoparasite medications, vaccinations, nail trimming and neutralizing/sterilization of all the owned cats be ensured.

► Handle cats appropriately and safely to avoid bites and scratches. Regularly groom and inspect the whole body for fleas and ticks. Don’t eat, drink, apply cosmetics or use tobacco products while handling animals. Regularly vacuum and disinfect the surfaces, bedding, toys and other equipments. Launder the soiled clothing separate from personal clothes.

► If someone is licked by the cat particularly on their face, mucous membranes or an open wounds, the area should be washed immediately and thoroughly using soap and water.

► Children should be sensitized to inform elders any change noticed in the behavior, symptoms and injury in the cat.

► Wear gloves and respiratory protection while handling infected animals, their body fluids and waste.

► The cat showing any indication of ailment should be taken to a pet specialist.

► Confine cats under treatment to one room until they get cured. Subsequently disinfect the room thoroughly.

► Seek immediate medical consultation for all types of the animal bite or scratch injuries and suspicion of getting any zoonotic disease.

In summary, people need to be aware of the health risks associated with cat ownership. It should be emphasized that the children and elderly with compromised immunity are more prone to the zoonotic diseases. Owner’s who look after their pets properly, ensure that they are well nourished, scientifically managed and regularly examined by a veterinarian have little to fear.

Mujeeb Fazili, Ex-Prof. & Head, Division of Veterinary Clinical Complex, FVSc & AH, Shuhama