Aches and pains can cause pets to lose their appetites simply because they don't feel well. It can also make it harder for pets to get to their food bowls on their own; and even if they're able, they may not do so because it hurts too much.joint problems like arthritis. Ask your vet to assess your dog; supplements like glucosamine really help some dogs (and if your dog doesn't take pills easily, try a glucosamine 'treat' like Glyco-Flex Soft Chews for Dogs). Others may need to take anti-inflammatory or pain medication.
Some types of illnesses (or the drugs used to treat them) can cause nausea, making the pet uninterested in eating. Examples include liver disease, kidney disease, and sometimes dogs undergoing chemotherapy for cancer.
Not all medical conditions cause inappetence, though; Cushings Disease is one example that can cause dogs to have voracious appetites. Certain drugs can also increase appetite.
As dogs get older, they can develop health conditions that decrease their mobility. Examples include arthritis and degenerative myelopathy. Dogs who find it hard to move around on their own will also find it hard to get to their food bowls - even if they want to eat. Place the bowl within easy reach of your dog, and invest in a bowl with a weighted bottom so that they can't knock it over.
Loose teeth, abscesses, inflamed gums, or sores in the mouth can all make eating uncomfortable or even downright painful. Most of us don't often look in our dogs' mouths... but if your dog seems to be reluctant to eat, or picks up food and drops it, or seems to have trouble chewing or swallowing, it's time to investigate further. Check your dog's teeth, gums, and mouth to see if there are any obvious sores, redness or inflammation, or loose teeth. A trip to the vet can also be helpful because the they know what to look for, including any sort of obstruction that's preventing the dog from eating properly. Keep your dog in good dental health with regular cleanings, by brushing their teeth and even using dental sprays, gels, or water additives in-between cleanings.
If you gently pull up the skin between your dog's shoulder blades and then let go, the skin should normally settle back into place quickly. If it doesn't, that could be a sign of dehydration. Other symptoms include 'tacky' gums (instead of slippery) and thick saliva.
The vet can give your dog fluids subcutaneously to help him feel better quickly. Once your dog feels better, he will hopefully regain an interest in eating. Dogs who keep getting dehydrated (and an underlying cause cannot be found or corrected) may need fluids regularly. Your vet can show you how to do this at home if need be.
Older dogs can become senile just like people can. As strange as it sounds, they may forget to eat or simply lose interest. A veterinarian can help assess whether or not there is a cognitive decline in your pet.
It might seem benign to simply feed your dog when it's hungry (goodness knows, it can't possibly be comfortable for the dog to always feel like it's hungry!). The problem is, this can easily lead to weight gain - and for senior dogs who often have other health and mobility issues, the extra weight can make these problems worse.
Sometimes medication can cause dogs to have an increased appetite. Talk to your vet about adjusting the dosage, to use the minimum possible amount that is still effective for treating your pet's condition. Do not stop giving the medication or adjust the dosage without first consulting with your veterinarian. There are drugs, like prednisone, that dogs have to be slowly weaned off.
Here are a few ideas for trying to deal with increased appetite problems. You can try them in combination, too. Check with your vet first if you're changing your dog's diet to make sure it won't negatively impact his health.
Talk to your veterinarian about what steps you can take to counter-act decreased appetite problems or inappetence. In some cases, if it's a drug making your pet nauseous, an alternate drug might give your dog his appetite back. Ask the vet if it's okay to try a lower dose of the drug to see if that might help too. Don't change your dog's medication dosage, or give your dog any new medication, without first discussing it with your vet. This is critically important; some drugs aren't suitable for dogs, others cannot be abruptly stopped, plus there are drug interactions to think about.
On a personal note, my own dog experienced a dramatic loss of appetite due to liver disease. Here are some ways I was able to encourage my dog to eat. Every little bit helps.
It isn't easy persuading a dog to eat when he doesn't want to (or, conversely, trying to fill up a dog who's constantly hungry). Sometimes it really does mean that the time has come to say goodbye, because a good quality of life is no longer there. But this isn't necessarily the case. Be creative, try new things, and work closely with your vet to try to resolve your senior dog's appetite problems.