Hello and thanks for contacting Ask Extension. Based on the pictures you submitted I think it is winter damage plus damage from your dog peeing on the leaves. Winter injury is the most common issue affecting boxwoods, especially in cold climates like Michigan. It typically appears as browning on the upper or outer leaves and stems once snow recedes, with green foliage remaining below the snowline. This damage is often caused by extreme cold (below -10 degrees Fahrenheit), especially in areas exposed to direct sunlight or near pavement. Fortunately, if the injury isn’t severe, affected areas can be pruned and plants often recover.

Other environmental stressors like salt damage and drought stress can also cause browning in boxwoods. Salt spray from sidewalks can desiccate foliage, especially on the side facing the salt source, while salt buildup in soil can interfere with water uptake. Drought stress is most common in newly planted boxwoods or during extended dry periods and typically shows as browning in the center of leaves and yellowing foliage. Identifying the pattern and location of damage can help distinguish between these causes and guide appropriate care.

As you know there are other problems that effect boxwood. I’ve included several links to articles about some other possible problems. There are some great pictures in these publications and you can compare your plants to these pictures and that may help you diagnose if it is something more than just winter damage. For example: if you have boxwood blight you will see black streaking on your stems. If you have boxwood leaf miner you might be able to dissect a leaf and see if you can find a small worm hiding inside the leaf. If you want a definite diagnosis you can send your pictures to this email address <personal data hidden> This is the email address for the Plant and Pest Diagnostic Lab at Michigan State University. If they can’t diagnose from your pictures they may ask you to send in a couple branch samples. Here is a link to their website that will give you instructions on how to send in your sample. https://www.canr.msu.edu/pestid/

Here are the links to articles with great pictures to help you with your diagnosis.

https://www.canr.msu.edu/resources/whats-wrong-with-my-boxwood-common-issues-and-solutions

https://www.canr.msu.edu/news/boxwood_insect_pests

https://extension.umd.edu/resource/boxwood-identify-and-manage-common-problems/