Most problems occur when many quails are being kept together or are being neglected. As long as you have been following the suggested day-to-day and week-to-week routines it is unlikely that you will have any serious problems.
Your quails might get these:
Worms - Round and Tape. These are the most likely types of worms that your quail may experience. Symptoms: Drop in egg production with an increase in hunger. Birds can also have diarrhoea as a symptom, although diarrhoea alone does not mean worms are the culprit. Contact a vet who will give you medication to be included in your bird's feed.
Lice - Symptoms: White build up around the feather base near the vent, in a bad case there could be a build up on feathers as well. The whiteness is lice eggs. If you do find lice eggs around the vent when checking the quail's health, brush them off and rub vaseline around the area, (sulphur ointment is better than killing lice if the problem persists). To prevent this, dust the nestbox with louse powder every week or so. Don't panic, they will not spread to you or other animals!
Red Mite - Symptoms: Egg production will go down. In a bad case the bird could look a bit pale from blood lost to the little suckers. You will not be able to find any by inspecting your birds during the day as they only crawl onto the birds for a nibble at night. Have a look every month or so for mites in the crevices at the ends of the roosting bars. There are mite-sprays available to prevent this for certain periods of time.
Northern Mite - Symptoms: In bad cases, scabby comb, face and wattles. They tend to gather around the vent and are grey/black. Again mite-sprays are available to stop them.
It is very unlikely that your quails have this:
Infectious Bronchitis: Symptoms: Drop in egg production and thin, rough and wrinkley egg shells. Sneezing and gaspy birds with a discharge from the nose. Your quail will be very unlikely to catch this airborne disease as they were vaccinated before you got them, but it is still possible. The illness should only last for a couple of weeks. Egg production will improve again but will probably never be as good as before, with more occasional dodgy eggs.
Aspergillosis -Symptoms: Thirsty, wheezy, lethargic. Avoid this by making sure you clean the dropping tray regularly. Young birds are most vulnerable, but adult birds can be infected. It is caught by breathing in spores from mouldy matter. Unfortunately there is no cure! The best thing for the quail would be to put it out of its misery, or get a vet to do it for you.
Scaley Leg - Symptoms: Scaley legs! The mites live on the legs under the scales which start to lift up and can give the bird trouble walking. There are two ways of treating scaley leg. You could purchase a general bird scaley leg treatment. This is available from the Omlet Shop or local pet shop. Alternatively you can cover the legs with vaseline which suffocates the mites and over a period of several days allows the legs to recover.
Not good if your quails has this:
Newcastle Disease - Symptoms: Birds craning skywards in an attempt to breathe. Green loose droppings. The good news.. No cases have been seen in the UK for around 20 years! The bad news.. The day after you see the symptoms in the bird, it will be dead. Contact a vet if you suspect this to have caused your bird's demise.