rabbit ear fur loss

Question
My rabbit is a netherland dwarf himilayan color buck.  I think he is going through a molt but am a little concerned because his ears have developed a thin patch that is almost bald.  His ears were chocholate colored when we got him at 6 months of age.  He is now about 9 months and over the past month his ears have been getting lighter as well as his legs.  I am not sure if this is just part of his summer molt or something to worry about.

Answer
Dear Allison,

If the bald patch doesn't fill in soon, please see:

www.bio.miami.edu/hare/furloss.html

for some ideas and information about abnormal fur loss in rabbits, and the safe treatment thereof.  You can find a good vet to help you here:

www.rabbit.org/vets

The Himalayan mutation in mammals is an interesting one:  it's temperature sensitive!  The darker areas of the body are dark because those skin cells are able to produce melanin (the dark pigment we all have in varying degrees of concentration) at the cooler temperature of the "points" on the body (tail, ears, legs, nose).  The trunk of the body is warmer, and the genes that code for the pigment production are inactivated at the higher temperature.

Interestingly, when the weather is warm, the genes in the "points" can also be inactivated to some degree, producing less pigment than when the temperature is cooler.

In very cold climates, even the body fur of a Himalayan animal can start to produce *some* pigment, making them buff colored with dark points.

The Himalayan mutation can very in temperature sensitivity.  But in general, more pigment is produced in cooler areas of the body.  So I wouldn't worry about your bunny's lighter summer coat.  When the weather cools down and his new coat grows in, it will probably be darker.

Hope that helps!

Dana