&middotDrought damage - needles gradually turn yellowish-green and then light brown. This starts at the top of the tree and progresses downward and from the outside in. &middotAnimal injury - dog urine can cause some browning and dropping of lower branches on arborvitae and junipers.
There are many different brands of cat flea collars. Generally, flea collars work by either emitting a toxic gas to the local area (head/neck of the pet) or by exuding chemicals that are absorbed into the animal's skin. Some flea collars have an Insect Growth Regulator (IGR), to prevent development of cat fleas, eggs and larvae.
Flea collars, however, cause severe irritation on your ferret's skin and can lead to serious health problems because of the dichlorvos they contain. Flea collars should NEVER be used on a ferret! Also, do not let your ferret in contact with the flea sprays or powders used on your floors until it is safe to do so.