EDITOR – Please see my comments to your article regarding the sterilisation of feral cats. Journalists have a responsibility to report science and public health side of “feel good” articles too.
Feral cats should be removed altogether and rehomed with containment or humanely euthanised. It is faster, safer, humane, and cost effective to euthanise feral cats. Neutering does nothing to prevent rabies spread, endo and ecto parasite spread, including plague (Yersinia pestis).
Cats can themselves become infected with black plague, Yersinia pestis, and transmit all three forms (bubonic, septicemic, pneumonic) to humans. They can also vector the plague carrying fleas from rodents into human’s homes or buildings and places of work. The practice of neuter release of feral cats will do nothing to prevent cats from spreading disease to humans and wildlife. Neutering a cat does not prevent it from transmitting diseases dangerous to public health. Feral cats should be controlled by humane field euthanasia and hygienic removal by trained professionals. Pet cats should be neutered and contained and kept flea free.
It is also a myth that neutering a feral cat will prevent it spreading rabies. Rabies vaccination in cats requires a primary vaccination at two to four months, a booster at one year, and again a booster at two to three years, depending on the manufacturer. Because feral cats seldom have personal identification and responsible owners who keep veterinary records, a clipped ear on a neutered cat is absolutely zero guarantee that the cat was ever vaccinated or had the required boosters. Cats can and do transmit rabies if they have had contact with a rabid animal and been infected. Even young kittens can be rabid prior to vaccination and the vaccination will be ineffective. A cat in poor health with a compromised immune system is also unable to respond adequately to rabies vaccine. Rabies is fatal unless the human is immediately treated with rabies immune globulin followed by four rabies vaccinations on a 14 day schedule. Neutering a feral cat does not prevent rabies.
Neutering a cat does also not prevent it spreading the protozoan cat parasite, Toxoplasma gondii, into the food and water supply of livestock and humans. A single infected feral cat, neutered or not, will spread millions of Toxoplasma gondii into the soil over a period of three weeks or more. The oocysts stay infectious in the soil, depending on conditions, up to 18 months or longer. It takes only a single oocyst to infect a pig.
In humans, the cat parasite Toxoplasma gondii can cause fetal demise in the first trimester of pregnancy, severe birth defects in later pregnancy, including hydrocephalus or microcephaly, as well as blindness and deafness. When human adults acquire the parasite, the results can be minimal to deadly, with a large range in between, including vision loss. In patients infected with HIV, untreated, the toxoplasmosis is common cause of death as it can cause a fatal encephalitis when the parasite infects the brain. The cat parasite Toxoplasma gondii is life long and can re emerge fatally in people who have depleted immune systems due to age, illness, cancer treatment, or HIV, or other immune depression.
In terms of public health, neuter release of feral cats is a waste of time and money. Limited resources are more effectively used in humanely field euthanising feral cats that are otherwise unsuitable for indoor or otherwise controlled living in a responsible home, where fleas will be controlled, faeces cleaned up and removed, and rabies vaccines maintained current. Public education on the value of controlling feral cat populations by removal and euthanasia or rehoming and control will maintain public health standards.
Cats also cause serious economic losses to farmers who are breeding sheep, goats, and pigs. The cat parasite causes abortus in livestock and can cause economic losses of 20 per cent or more in a breeding season. Cats are not safe or suitable control of rodents in livestock grazing areas and should be removed from watersheds, agricultural areas, and grazing areas. Rodent and flea control is very important to public health, but feral cats in the modern world are part of the public health hazards, not a solution.
Dr Johanna van de Woestijne
California resident, born in South Africa
