&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.
Tick Collars. Collars that repel ticks are an additional preventive you can use, though they are mainly only useful for protecting the neck and head from ticks. The collar needs to make contact with your catâs skin in order to transfer the chemicals onto the catâs fur and skin.