www.roanoke.com

Paws & Claws

Jill Bowen has practiced veterinary medicine in England and Texas. She lives in Blacksburg now, and answers local pet owners' questions every week in The Roanoke Times and roanoke.com.

Recent columns

• Bacteria can cause ear infections in cats
• Chiari is a malformation of the back for some spaniels
• Your plant smells like a great spot to ...
• Sting salve: meat tenderizer

Since the scare over melamine in dog food, I have been giving my dog table scraps, which he loves. Now my neighbor says I may be poisoning him by giving him people food. What particular foods might be poisonous?

Depending on what you are feeding your dog, you are probably not doing him any harm.

Before the advent of the very profitable commercial dog food market, dogs were routinely fed table scraps with plain biscuit meal added for the larger breeds. Foods that you should avoid feeding because of their potential side effects and toxicity include onions and garlic because dogs and cats lack the enzyme necessary to properly digest onions, and this can result in gas, vomiting and diarrhea.

If large amounts of garlic and onion are eaten daily, the red blood cells become fragile and break apart because of the chemical thiosulfate present in the plants. Depending on the amount eaten and the size of the dog, symptoms may develop either immediately after eating the onion or as long as a few days later. If the dog becomes severely anemic, it could be fatal.

All forms of onion and garlic are at fault including raw, dehydrated, cooked, powders or even when used in baby foods for taste. Homeopathic garlic pills used for flea control can be a problem if the stated dose is exceeded.

Xylitol is a sugar-alcohol sweetener used in sugar-free products such as chewing gum, candy and diet drinks. Dogs that consume a large amount can develop a sudden drop in blood sugar, often starting within 30 minutes of eating the product and lasting for hours. Any dog showing symptoms of weakness, lethargy, incoordination, collapse or seizures needs to be seen by a veterinarian.

Less-common foods that can cause problems include chocolate, avocados, apricots, cherries, plums, grapes, raisins, macadamia nuts and caffeine. Dairy products are not particularly dangerous, but high-fat milk may precipitate pancreatitis. Most cats lack the enzyme to digest the milk sugar called lactose. The undigested lactose causes diarrhea, a problem shared with some dogs. Most dogs can tolerate small amounts of plain yogurt and cheese.

Many dogs like fatty foods, but too much can cause painful pancreatitis. Particularly at risk are poodles, cocker spaniels and miniature schnauzers. Pancreatitis is very painful and occurs in conjunction with the normal signs of a gastrointestinal upset of vomiting and diarrhea.

Chocolate has a high fat content and contains both caffeine and theobromine. These two compounds stimulate the nervous system and are toxic in large quantities. The amounts of caffeine and theobromine vary according to the type of chocolate: Baker's chocolate, dark chocolate or cacao beans have the greatest amount, while white chocolate has the least. Coffee causes the same symptoms as chocolate, including restlessness, twitching, panting and in serious cases where a large amount of dark chocolate or coffee grounds have been eaten, the dog may have a seizure.

Baking powder and baking soda are present in most baked items, especially commercial goods. Neither product is good for dogs and can cause an electrolyte imbalance that, over time, can cause congestive heart failure or muscle spasms.

Also, the ingestion of avocados has been reported to be toxic in dogs. The toxin is persin, present in all parts of the avocado. Grapes and raisins can cause problems in amounts varying from 9 ounces to 2 pounds, again depending on the size and weight of the dog. Kidney failure is the most common effect of eating these fruits.

Macadamia nuts, also known as Australia or Queensland nuts, can also cause toxic but nonfatal symptoms of gastric upset.

Finally do not feed pets any moldy or rotten food. Few dogs are discriminating feeders, especially when hungry, and food that is rotten will undoubtedly cause stomach upsets. Never feed food from a damaged can because it could cause botulism, which can be fatal.

Jill Bowen has practiced veterinary medicine in England and Texas and has taught at Texas A&M University. She lives with her veterinarian husband and two cats in Blacksburg. If you have a question, please write to her in care of The Roanoke Times, P.O. Box 540, Christiansburg, VA 24068, or send an e-mail to bowen508@verizon.net.