Why does my dog get tired and lie down to sleep while playing?

If it's quite hot where you are, that can explain why Snowball isn't playing as much as usual. That would be a good thing, as playing too much in the heat will lead to heat stroke, which is too often fatal. I would keep an eye on her, and make sure she stays as cool as possible. If this behavior does continue, a check up with the vet to be safe would be recommended. I hope this helps!

If he is regularly active and has this issue than that would be concerning he could have some arthritis in his joints due to dysplasia or another conformational abnormality. We can also have heart issue lead to weakness, or neuromusclular disease such as myasthenia gravis. If he is getting very tired every once in awhile after a rare day of lots of activity (say he normally goes on a 20 minute long walk every day, but this weekend he walked for 5 hours and is sore the next day) then this could just be that is is overexerting himself. But what you are describing sounds more concerning and I would recommend a visit to his vet for an examination.

Thanks for using Petco Pet Education Center, formerly Petcoach! Lethargy is a fairly non-specific sign of illness. This could be a sign of many things that go from discomfort or pain to anemia. I recommend that you have Tippy evaluated by your veterinarian for further assessment and treatment. Further diagnostics would be based on a thorough physical examination performed by your veterinarian. Treatment would be based on findings. Good luck and have a good night!

Yes she may need a rest. With agility dogs and other canine athletes we recommend one day off a week for rest with only short walks and no heavy activity. These dogs also get a month off during the year to just relax and be a dog. This helps them recover from long bouts of strenuous physical activity. If you give Belle a week or two of reduced activity and plenty of rest and she doesn't get her energy back then I would bring her in for an exam. They will check her for joint pain and run a blood panel to rule out metabolic issues. She's probably fine from your description so let her be lazy for a while and see how she does. Thanks for using Petco Pet Education Center, formerly Petcoach to help you care for Belle.

Given that this is a change to his behavior a quick check up to rule out underlying medical causes such as heart disease or early arthritis would be recommended. If all clear then limiting the exercise to 50-60% of the current time and reducing the intensity by throwing them less far should keep him interested and excited without tiring him completely

There could be many reasons that he has slowed down and doesn't seem as active. It could be related to arthritis, neck/back pain, endocrine disease, infections, kidney/liver disease, parasites, etc. Have a vet take a look at him to help determine the cause. Your vet can run lab-work and take x-rays to help diagnose and treat. He may need an anti-inflammatory and joint supplements to help.

Cardiovascular or respiratory issue may provoke acute collapse during intense exercise or the signs you are describing may be completely normal. The only way to differentiate between a pathologic and normal condition would be to have Ellie checked up at your local veterinarian. A physical examination may reveal subtle signs compatible with cardiac or cardiovascular disease. Please do not hesitate to contact us again on the forum or by requesting a consultation if you have any more questions or to discuss it any further.