She sounds like she has mucus in her airway, probably from a respiratory disease. In the UK antibiotics are only available through a vet, so I would get the droppings checked for gapeworms while you are there. The vet may want to also give a more powerful dose of wormer that would treat gapeworm as well. There are a handful of respiratory diseases such as infectious bronchitis, mycoplasma gallisepticum, coryza, ILT, and ORT that can cause various symptoms. Some are caused by bacteria and some by viruses. Antibiotics can treat bacteria, or can help to prevent secondary infections.
