If that is his resting heart rate, you do want to keep an eye
on that. If he is a sighthound or a very athletic dog, then that could explain why his heart rate is so low, but generally speaking we'd want to see it around 60-120 bpm at rest. So, if he isn't one of those 2 exceptions, you may want to have this checked by his vet.
In any case, his heart rate doesn't really have any bearing on our current signs. As well, I would note that an obstruction or something being caught is unlikely here since he can eat and the food can travel down the esophagus. Instead, he likely has irritation or inflammation in the throat. This could be related to something having abraded the throat on its way down but could also be related to a esophagitis, or a possible viral or bacterial tracheitis.
Therefore, if he is breathing comfortably (<30 bpm) and his gums are pink (a sign of proper oxygenation), you can focus on soothing his throat at this stage while monitoring. To do so, you can try him with plain over the counter glycerin/honey cough syrup (with no drugs in it). Typically we will give a milliliter (~1/4 teaspoon) as needed. This will aid to soothe his throat and settle any upper airway related coughing. Alternatively, you can try Robitussin DM
. If you choose to use this one, I would just say to make sure to use this preparation and avoid any containing other medications like Paracetamol, Acetaminophen, Pseudoephedrine, Phenylephrine or caffeine (since these can be toxic
). If it also contains Guaifenesin that is okay. Dose-wise, we tend to give this as 1/2 (half) teaspoon per 10lbs of the dog's body weight every 8-12 hours. These will help soothe throat irritation and can help at least decrease the coughing, retching, and throat irritation. As well, it can help to offer soft foods to just avoid any more throat irritation or abrasion.
Overall, his signs do sound like he has some irritation (possibly related to something he ate) in his throat. That said, considering the rest of his history, we'd not expect something to be stuck here. Therefore, if he is more settled, we'd just want to use the above supportive care at this stage. Otherwise, if he seems very irritated in his throat, then we'd need to consider having his vet examine him and potentially start him on a gastroprotectant to coat his throat and a dog safe anti-inflammatory to soothe any inflammation and reduce any soreness for him. And at the same time, they can check to see if this slowed heart rate is still ongoing or if it has elevated once he gets moving.
Please take care,