Tretinoin/benzoyl peroxide, sold under the brand name Twyneo, is a fixed-dose combination medication used for the treatment of acne. It contains tretinoin, a vitamin A derivative, and benzoyl peroxide, an oxidizing agent.The combination was approved for medical use in the United States in July 2021. References
External links
"Tretinoin". Drug Information Portal. U.S. National Library of Medicine. "Benzoyl peroxide". Drug Information Portal. U.S. National Library of Medicine. Clinical trial number NCT03761784 for "A Study of S6G5T-3 in the Treatment of Acne Vulgaris" at ClinicalTrials.gov
Clinical trial number NCT03761810 for "A Study of S6G5T 3 in the Treatment of Acne Vulgaris" at ClinicalTrials.gov
The test determines whether the mutated copy of SOD1 is present in the DNA sample submitted. It must be interpreted with caution by a veterinary clinician in combination with the animals clinical signs and other lab test results. The results reported are:

Normal / Normal (N/N, or clear): The dog does not have the mutation and is extremely unlikely to develop degenerative myelopathy. There have been cases, however, in which dogs that tested clear were found to have DM upon necropsy. Normal / Abnormal (N/A or carrier): The dog has one mutated copy of the gene (is heterozygous) and is a carrier but will not have degenerative myelopathy though there has now been some cases of heterozygous carriers developing DM. It will be possible for it to pass the mutation to offspring. A thorough examination of the dogs pedigree and DNA testing should be undertaken prior to breeding a dog with this result. Abnormal / Abnormal (A/A or At Risk): The dog has two copies (is homozygous) for the mutation and is at risk for degenerative myelopathy. Genetics
Breeding risks for degenerative myelopathy can be calculated using the Punnett Square:

If both parents are clear (N/N) then all of the puppies will be clear. If one parent is a carrier (N/A) and one is clear (N/N) each puppy has a 50% chance of being clear and a 50% chance of being a carrier.