There are several reasons why squirrels experience hair loss that can range from a fungus infection to parasitic infestation and even vitamin deficiency and dietary problems. They can even lose hair by repeated physical activity!
There is a fungal infection called “Dermatophytosis” that is commonly found in squirrels. A fungus requires moisture and warmth to grow. Dermatophytosis is common in the Spring of the year and whenever the weather produces warm and moist conditions. Dermatophytosis attacks the hair shaft at the skin line causing the hair shaft to become brittle so that it easily breaks off. It also produces a mild itch that will cause the squirrel to scratch and bite at the area. This action causes the hair to break off and leave a bald area. There is usually not much skin irritation or scabbing. Just bald spots that spread as the fungus spreads and the squirrel keeps scratching. If this is found on a captive squirrel, one way to make the diagnosis is to grasp a few hairs on the edge of a bald spot and give them a gentle tug. If they break off, it is probably Dermatophytosis.
No treatment is mandatory for Dermatophytosis because the squirrel's immune system will eventually overcome it. I would not recommend seeking a prescription anti-fungal medication for this condition because the potential side-effects of most of these products are worse than the disease.
I use a couple of natural products that are completely safe to use, yet are very effective at treating a fungus. One is cold-pressed organic Coconut Oil. It's important that it is cold-pressed and unprocessed because processing and heat destroys the substances that kill fungus. Another substance that can be added to the squirrel's water and applied topically is Colloidal Silver. Both of these substances can be found on our Squirrel Mall.
Another cause of hair loss in squirrels is a parasitic infestation of Mange Mites or Sarcoptic Mange. The insect that causes this is called Sarcoptes scabiei. They can only be transmitted skin-to-skin by close contact and squirrels pass them to each other when they sleep together in cold weather. The mites cannot live off of a warm host for more than an hour and are incapable of jumping from one squirrel to another. A massive infestation to a squirrel can be life-threatening because they are blood-feeding insects and can produce anemia and a weakened immune system. Since they borough under the skin, they cause intense itching which often results in open wounds and scabbing. ( Note: If you have squirrels in a cage that have never been with wild squirrels, it is impossible for them to get Mange!)
There are two ways to treat Mange. The quick way is to use a tiny dose of Ivermectin 1.87% This is recommended in massive infestations where the squirrel's life is endangered.
The other way to treat it is to add a couple teaspoons of Colloidal Silver to the squirrel's drinking water. It doesn't kill the adult mites but will weaken the cell wall of their eggs so that the killer T-Cells of the immune system can penetrate and destroy the larvae. When the adults die, the infestation is gone!
Another thing that can cause hair thinning and loss is low Vitamin D levels. Squirrels synthesize Vitamin D from exposure to direct sunlight, (not through glass.) Glass filters out the spectrum of light needed for this synthesis to take place. We have found that a simple incandescent plant light shining on the squirrel's cage for 4 to 6 hours a day helps the squirrel synthesize Vitamin D. (Note: Oral supplementation of Vitamin D is not recommended because of the difficulty of proper dosing and the distinct possibility of damage to the squirrel's liver!)
Squirrels can experience hair loss and thinning from dietary problems. Excessive salt in the diet can cause the hair to thin and fall out especially in the tail. Squirrels should never be fed salted nuts! Nuts should be raw or unsalted and should comprise no more than 20% of their daily intake of food.
The other dietary cause of hair thinning an loss is hypoprotinuria. This simply means not enough quality protein in the diet. This is a biggie, because there is a misconception out there in the squirrel rhetoric that says that squirrels are strict herbivores and should never be fed anything resembling meat protein. Yet, if you study the dietary habits of squirrels in the wild, you will find that they eat bugs and worms and have been known to raid bird's nests to eat bird's eggs and even baby birds. This activity points out the fact that they cross-over and eat protein.
We discovered this with our 11-year-old blind squirrel recently because she was losing muscle mass and had chronic fur missing from the top of her feet. She also had stopped gnawing so we were having to feed her a dental soft diet and trim her teeth every couple months.
I decided to try adding raw egg yolk to her diet by mixing it in to the soft food balls that we are feeding her. After a couple of weeks she started to put back on muscle weight and now the hair that was missing from her feet is starting to grow back in!
So, squirrels do need high quality protein to keep their muscles strong and to facilitate hair growth!
Squirrels can also lose hair from habitual activity like gnawing at cage wire. When a squirrel wants out of a cage they will often run their teeth up and down the vertical wires of their cage. If they are able to get their nose between the wires, you will often find fur missing from the top of their nose. This loss is caused by their nose rubbing up and down an adjacent parallel wire on the cage.
This sums up most of the reason why and how squirrels lose hair. If you have any questions about squirrels and their behavior you can always check the list of Blog topics on my website http://SquirrelNutrition.com or contact me by e-mail at SquirrelHelp@Gmail.com.
We're always willing to help with your squirrel questions!