Monitoring the Colony

Part of Ireland's TNR Manual

How to Help Community Cats

Adapted for Ireland from Alley Cat Allies.

See also our Monitoring the Colony guide for Trappers.

Keeping track of members of your colony, their health, new cats who have joined the colony who may need to be neutered, and your ongoing Trap Neuter Return program allows you to monitor your progress and provides you with back-up evidence that may be needed someday.


It is a good idea to keep an eye on the cats for general good health. Common indicators of health problems or injury include: changes in behaviour, changes in eating habits, dull eyes or coat, discharge from the nose or eyes, weight loss, fur loss, changes in their gait and/or listlessness. Have a plan with your veterinarian for how to handle any health problems and for ongoing colony care. When a health problem occurs, speak with your veterinarian first and describe the symptoms so that you can decide together if a sick cat needs to be trapped and examined.

For ongoing colony care, ask your veterinarian to provide you with deworming medicine and antibiotics to have on hand to care for minor health problems. Have a financial plan in place for any cats that may need veterinary care due to injury or illness. It is important to find a veterinarian or low-cost clinic familiar with or willing to learn how to work with feral cats. Check our listing of Feral Friendly Vets. If the veterinarian you ultimately choose has no experience with feral cats, he or she can learn more about treating feral cats

Read more about working with a veterinarian.

Flea Control

Your veterinarian can apply a long-lasting topical flea control product such as Advantage when the cats are anaesthetised for neutering. There are also oral flea medications  that can be added to the food, but monitoring the dosage can be difficult for community cats, who share food. Change the bedding in shelters at least twice a year. At that time, spray or dust the floor with a cat-safe flea control product. Or, sprinkle food-grade diatomaceous earth beneath the straw to deter fleas. Sprinkling mint or dried pyrethrum flowers beneath the bedding may also help. Fleas are a natural part of life outdoors, so while you can try your best to control them, they are not something you need to be worried about excessively.


It is not uncommon for feral cat colonies to have tapeworms. These can be treated with dewormer when they are taken in for neutering. If you find that your colony of already neutered cats has worms, it is not something you need to worry about a lot. Tapeworms will not harm otherwise healthy cats. However, you can ask your vet for advice on treating the colony for worms. As with flea treatment, the main problem will be monitoring the dosage for cats sharing food.

Record Keeping

You should hold on to all medical records for each cat in every colony for which you care. A medical record should contain a listing of each vaccination (if given) and any other medical procedures. The record should also include documentation of the cat’s neuter and, if the cat was micro-chipped, the manufacturer, and the number of the chip. Include a photo of each cat with his or her record. Make sure to update the photo occasionally as their colouring and size can change with age.

You should always be prepared for the possibility that someone such as animal control could question the status of your colony. This is why it is important to keep current, accurate health records for all of the cats.

One way to stay organised is to keep all information for a colony together in a ring binder. Not only will you be prepared to provide documentation about your cats if needed, you will also represent yourself as well-organised and on top of the situation when conversing with neighbours about the cats.

Use our Planning Form to help keep organised records.


Next Step: Helping cats and people to co-exist – what you can do


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Part of Ireland's TNR Manual

How to Help Community Cats