Changes

===Using Fluorescein to Identify Cats Responsible for Urine Marking or Elimination===

===Using Fluorescein to Identify Cats Responsible for Urine Marking or Elimination===

When ingested, fluorescein dye is excreted intact in urine, and can be made to fluoresce using a woods lamp. This can be used to identify the cat responsible for leaving urine deposits.However, the fluorescence of fluorescein treated cats varies with pH. The fluorescence of fluorescein varies with pH, such that it only strongly emits light under UV illumination when it is in a neutral or alkaline solution. In acidic solution it may hardly glow green at all. Spots should therefore be sprayed with a buffer solution of sodium bicarbonate (baking soda), which will produce a pH of around 8, before testing with a UV lamp.  

When ingested, fluorescein dye is excreted intact in urine, and can be made to fluoresce using a UV lamp. This can be used to identify the cat responsible for leaving urine deposits. A dose of 50mg/cat once daily is given, which is equivalent to the amount of dye in the tips of six fluorescein test stops (commonly used for ulcer detection in ophthalmology)<ref>Neilson, J. (2003) Feline House Soiling: Elimination and Marking Behaviors. "Veterinary Clinics of North America: Small Animal Practice". 33(2):287-301.</ref>day as a single dose with food is recommended. However, the fluorescence of fluorescein varies considerably with pH<ref>Sjoback, R., Nygren, J., Kubista, M. (1995) Absorption and fluorescence properties of fluorescein. "Spectrocmicia Acta Part A". 52. 7-21.</ref>, such that it only strongly fluoresces in a neutral or alkaline solution; in an acidic solution it may hardly fluoresce at all. Spots may therefore need to be sprayed with a buffer solution of sodium bicarbonate (baking soda), which will produce a pH of around 8, before testing with a UV lamp.  

* Fluorescein is available as sterile paper strips, for ophthalmic examination. These contain approximately 1 mg of fluorescein per tip, but this should be checked with the manufacturer.

* Fluorescein is available as large sterile paper strips, for ophthalmic examination. These contain approximately 9 mg of fluorescein per tip, but this should be checked with the manufacturer.

* The tips should be torn off and rolled to fit into gelatine capsules, giving approximately 5 per capsule (5mg).

* The tips should be torn off and rolled to fit into gelatine capsules, giving approximately 6 per capsule (54mg).

* This dose is given once daily for 3-4 days.

* This dose is given once daily for 3-4 days.

* Urine sites are checked daily.

* Urine sites are checked daily.

* Lightly spray each site with a solution of sodium bicarbonate (baking powder), mixed in water (1 tablespoonful in 125ml water).

* If necessary, lightly spray each site with a solution of sodium bicarbonate (baking powder), mixed in water (1 tablespoonful in 125ml water).

* A UV lamp is then used to check the site for fluorescence.

* A UV lamp is then used to check the site for fluorescence.

* It is vital to start by testing the least probable culprits first, working up to the most probable. Otherwise fluorescence marks left by one cat will obscure those of another. If it is certain that the culprit is a resident cat then the culprit may be identified by a process of elimination, which minimises the risk of leaving lots of fluorescent stains for the client to

* Leave 3 to 5 days between cats, to allow all of the dye to be excreted.

 

* A 5-day washout is left between testing of each cat, to make sure that each individual has excreted all of the dye before testing the next.

Although fluorescein is water-soluble and can usually be removed with normal cleaning, it can leave stains on light coloured fabric, carpets or wall paper.

* Although fluorescein is water-soluble and can usually be removed with normal cleaning, this testing method may leave stains on fabric, carpets or wall paper and owners must be warned of this.

Owners must be warned of this, because considerable damage can result. In addition, it is best to start by dosing those cats which are believed least likely to be responsible for the urine deposits. Using this method it is possible to make an identification based on exclusion, and therefore avoid any dye contamination of the owner's home.

 

Most mobile devices have a video capability, and webcams are relatively cheap. Movement triggered apps and software enable the video function to be activated when cat comes into range. If certain locations are regularly  marked or soiled, movement triggered video recording can be used to identify the culprit. This can be particularly valuable when it is suspected that urine marks are being deposited by non-resident cats entering the home.

==Cooperation Between Cat Owners==

==Cooperation Between Cat Owners==