There are a number of reasons why your dog is throwing up after he has drunk water. The most obvious one is that he is drinking it too fast, which could make him take in too much air when he drinks, which will result in him throwing it back up.
If you think that drinking too fast is the reason, examine why this may be the case. If he does not have constant access to water he may be so thirsty he gulps the water too quickly, so this should be easily remedied. If he does have constant access but still drinks too quickly, you can slow him down by either giving him smaller amounts and giving him more water every time his bowl is empty, or alternatively, place a smaller bowl upside down in his drinking water; this will also slow him down.
You can also place something that floats in the water so that your dog has to drink round it. This will slow him down but make sure that whatever you place in the water is not small enough that he could take it into his mouth and perhaps choke on it.
If this does not work, perhaps you should give him mineral water instead of tap water; he may be sensitive to some of the chemicals that can be found in tap water.
Another thing to think about is the temperature of the water; if it is too cold, his gut could react and make him throw it back up.
There is also the chance that there is something medically wrong with your dog. Before you panic, it could be something that is easily remedied, so if any of the above doesn’t work take him to the vet to find out.
If you think that drinking too fast is the reason, examine why this may be the case. If he does not have constant access to water he may be so thirsty he gulps the water too quickly, so this should be easily remedied. If he does have constant access but still drinks too quickly, you can slow him down by either giving him smaller amounts and giving him more water every time his bowl is empty, or alternatively, place a smaller bowl upside down in his drinking water; this will also slow him down.
You can also place something that floats in the water so that your dog has to drink round it. This will slow him down but make sure that whatever you place in the water is not small enough that he could take it into his mouth and perhaps choke on it.
If this does not work, perhaps you should give him mineral water instead of tap water; he may be sensitive to some of the chemicals that can be found in tap water.
Another thing to think about is the temperature of the water; if it is too cold, his gut could react and make him throw it back up.
There is also the chance that there is something medically wrong with your dog. Before you panic, it could be something that is easily remedied, so if any of the above doesn’t work take him to the vet to find out.