Listed below are health conditions identified in the Rottweiler.  It is very important to know the status of a dog/bitch before you breed!  It is just as important to know the status of the sire, dam and grandparents of a puppy you plan to purchase.
For Status results on a particular Sire/Dam or for more information on these genetic diseases: (hips, elbows, heart & thyroid) (eyes)
The Canine Health information Center also known as CHIC, is a centralized canine health datbase jointly sponsored by the AKC/Canine Health Foundation (AKC/CHF) and the Orthopedic Foundationfor Animals (OFA)
Mission Statement:
To provide a source of health information for owners, breeders and scientists, that will assist in breeding healthy dogs.
For a CHIC number: Rottweilers are required to test for:
  Hip dysplasia, elbow dysplasia, eye clearance and congenital cardiac database.
A dog/bitch  may acquire a "
CHIC" number.  This means the dog/bitch has been tested and revealed the results of all testing required does not mean the dog/bitch has passed all testing.
For more information on CHF/CHIC:

Hip Dysplasia
Hip Dysplasia is literaly defined as an abnormal development of the hip joint.  It is a terrible genetic disease because of the various degrees of arthritis (also called degenerative joint disease, arthrosis, osteoarthrosis) it can eventually produce, leading to pain and debilitation.  OFA will not certify a normal hip until the dog is 2 years of age.  Rottweilers Rank:
Rank      # Evaluations      %Excellent       %Dysplastic
29              91161             8.2                    20.3
Elbow Dysplasia is a general term used to identify an inherited polygenic disease in the elbow of dogs.  Three specific etiologies make up this disease and they can occur independently or in conjuction with one another.
1.  Pathology involving the medial coronoid of the ulna (FCP)
2.  Osteochondrities of the medial humeral condyle in the elbow joint (OCD)
3.  Ununited anconeal process (UAP)
OFA will not certify a normal elbow until the dog is 2 years of age.  Rottweilers rank:
Rank     #Evaluations      %Normal     %Dysplastic
3              3360                  59.5                40.0 

Grade 1:  30.1    Grade 2:  8.4            Grade 3:  1.5
Subvalvualr Aortic Stenosis (SAS) is a congenital heart disease characterized by a fibrous ridge located below the aortic valve.  Affected dogs are at risk of developing heart valve infections, congestive heart failure or sudden death.
A dog at 12 months of age, which auscultates normally is considered to be fee of congenital heart disease upon confirmation of this, the OFA will issue a certificate.  Rottweilers rank:
Rank   #Evaluations   %Normal   %Equivocal   %Affected
46          4763               99.3         0.3                    0.3
Eye lid Disorders:
Entropion: Rolling inwards--Frequently causes ocular pain and corneal disease
Ectropion: Drooping or rolling outward.
Although entropion and ectropion are hereditary disorders, their mode of inheritance is complex.  No one gene controls the development of eyelid conformation.

Hypothyroidism.  The thyroid gland is not prducing enough hormone to adequately maintain the dog's metabolism.
Autoimmune thyroiditis (known to be heribable)   is the most common cause of primary hypothyroidism in dogs.  The disease has variable onset, but tends to clinically manifest itself at 2 to 5 years of age.  Periodic retesting is recommended.
Rank   #Evaluations   %Autoimmune Thyroiditis 
57          772                      2,3

Rupture of the cranial cruciate ligament (CCLR) in the dog is the most common cause of hind limb lameness.  When CCLR occurs it results in instability in the knee leading to progressive, debilitating arthritis and lameness. 
Many Rottweilers are predisposed to CCLR
Studies have been done that support a genetic cause for the CCLR trait.