Why did my dog suddenly get a bald spot in the corner of his eye?

This does not look too dramatic, however I would observe the bald spot. If it enlarges or if other bald spots appear, then this may be ringworm which would need to be treated by a vet. Should crusts appear or the skin start to look scaly around the eye(s) your dog may be suffering from demodex mites, which nowadays is easily treated, if necessary.

Thanks for using Petco Pet Education Center, formerly Petcoach! This may be due to a mild traumatic injury. If she has been scratching more than usual and scratching at that area, have her evaluated by a veterinarian for further assessment and treatment. Otherwise, it would be fair to wait a bit to see if it resolves on its own. In that case, if no improvement is noted within 4-5 days, have her evaluated by a veterinarian then. Best of luck!

Thanks for using Petco Pet Education Center, formerly Petcoach! It does look like he has a small patch without hair. However, if it is not associated with itchiness, redness, discharge or a mass effect, I would continue to monitor him unless you notice any other symptoms like the ones described above. It may be just a periodic loss of hair which he will recover from uneventfully. Good luck and have a good night!

Hi there! Thanks for using Petco Pet Education Center, formerly Petcoach! There is a variety of reasons that can explain alopecia or hair loss. The causes can easily be differentiated by the clinical signs associated with it and the physical exam findings. If he is only showing some hair loss without scratching or overgrooming then it could conditions such as alopecia areata that can affect cats and usually resolves on its own. If there is evidence of scratching and you start noticing some redness or irritation associated with it, then other conditions such as allergies are possible. If you notice himovergrooming himself in that area then it could be something like psychogenic alopecia which is more of a behavioral issue. I think that since he is not having overt clinical signs and it is mostly hair loss, I think it is possibly transient and could resolve on its own. You can monitor this closely and if it does not resolve or it worsens then have him examined by your veterinarian. Good luck!

Thanks for using Petco Pet Education Center, formerly Petcoach! This is possibly due to allergies. It really comes down to figuring out what is causing her allergies so that they can be treated or the specific allergen avoided. A secondary infection is likely and also needs to be addressed. This could also be due to something like mites and that can be easily determined with an exam and basic cytology which your veterinarian can perform. There are medications such as Apoquel or prednisone which may help with the itch. 

There are many things that can cause allergies though in most cases they can be broken down into 3 big categories: flea, food and environmental allergies. 

Allergies are usually worked up in a stepwise fashion starting with flea allergies as this is the easiest and cheapest to take care of. If not on a flea preventative, then it would be a good idea to get started on one. If already on one then it would be a good idea to change to something else (there are many new products out in the market). 

If not improved in 1-3 months then it is time to move on and check for food allergies by switching to a novel diet (new protein and new carbohydrate). If that does not seem to be the issue then you are left out having to check for environmental allergies which require blood and/or skin tests.

 Allergies can be very frustrating to deal with at first but so rewarding at the end when we are able to treat them effectively!

Hello. From this picture that could be a small scar, could be a small bit of hair loss from many causes (scratching, infection, etc), could be inflammation of the gland, or could just be a wart or something. I would just keep an eye on it and if it bothers him or grows or changes, or if he starts squinting, to have it seen by a vet. Good luck with him!

Thanks for using Petco Pet Education Center, formerly Petcoach! This looks like a severe focal infection. I recommend you have her evaluated by your veterinarian for further assessment and treatment as this will likely require local therapy with cleaning of the site, pain control medications and antibiotics. Also, your veterinarian could check for a possible underlying cause like allergies, mites or a foreign body reaction. Good luck!