One of the most common reasons people take their pets to the veterinarian is for skin problems. Now, it's true that skin problems are not uncommon, but it's also true that they're often pretty obvious. When your cat is itching, the symptoms can be pretty hard to miss.

This is not so for metabolic diseases. While the skin is one organ you can see functioning, inside of your pet is an astonishingly beautiful, intricate and complicated system that works together to bring in fuel, turn it into usable forms and eliminate what can't be used, over and over with every breath and every heartbeat. Awake or asleep, or on the run, the body is always working. And when things start to malfunction, it's not always obvious.

While the symptoms of metabolic disease may be subtle, they're there if you keep your eyes open for changes. While a definitive diagnosis for these health issues will require a visit to your veterinarian, the first line of defense is always you. Many metabolic diseases can be treated, or at least managed, and the sooner they're caught the better it will be for your pet — and sometimes your bank balance.

Check in with your veterinarian when you observe any of the following symptoms, and listen to your gut when it comes to the "Ain't Doing Right" pet as well.

WEIGHT CHANGES >> While a pound up or down may not seem like much to us, to a 9-pound cat, it's a lot. This is the same for a small dog. Take your pet's weight every month or so; stand on the scale to get your weight, then stand on the scale with your pet and record the difference. For large dogs, I assure you that most veterinarians would be delighted to have you drop by and use their scale — many practices have them right by the reception desk. Any weight loss or gain that you can't account for should be checked out. All dramatic weight shifts must be checked out immediately.

CHANGES IN ACTIVITY LEVELS >> When an older cat suddenly starts being more active — sometimes dramatically so — owners are often delighted. Veterinarians know better: when an older cat starts zooming, it could be time to test the thyroid. That's one example, but there are others. When a pet's activity level changes — up or down — your veterinarian needs to know about it.

CHANGES IN APPETITE, DRINKING AND ELIMINATION >> Leaving out an always-open buffet for pets isn't a good idea for keeping weight at a normal level, but it's also not recommended for another reason. You can't tell when pets are eating more, or less. And while your pet should always have access to unlimited amounts of cool, fresh water, be aware of how often you're filling the bowl, and get a feel for what's normal, so you know what's not. And keep an eye on the other end as well. Be aware of your pet's waste products, specifically volume of urine as well as consistency, color and even smell of stools.

A dramatic increase in water intake can indicate diabetes, kidney disease or too much steroid production.

SKIN AND COAT CONDITION >> Some of those skin problems could be a result of metabolic issues such as patterned hair loss, changes to the texture of the skin and other issues.

Get into the habit of really looking at your pet and knowing what's normal (you have to know what normal is to recognize abnormal for EACH pet). It does take a little learning because many changes are hard to notice when you see a pet every day.

As always, talk about your observations and concerns with your veterinarian. Better to have something checked out and addressed than to let it go on and put your pet's long-term health at risk.

Dr. Darren Woodson has practiced veterinary medicine in the Farmington area for more than 28 years and has a passion for educating pet owners. If you have a question you would like him to address, email dwoodson@valleyvetpet.com. Please understand Dr. Woodson will choose the questions that are most relevant to our readers.