Chocolate & Other Dangerous Goodies

By Dr. Lucy Pinkston

In the past two weeks, we discussed holiday decorations that can be hazardous to your pet. This week, we discuss holiday treats that may also be hazardous. Many foods that are perfectly safe for us to eat ourselves can cause problems in dogs and some treats that are supposed to be made for dogs can actually be harmful in certain individuals. Below is a list of the most common treats that are likely to be troublesome, followed by a more detailed description of each one individually. Some of these cause only minor problems; others can be extremely dangerous.

1) Chocolate
2) Rich, fatty foods
3) Dairy products
4) Rawhides, cow hooves, & pigs' ears
5) Bones
6) Onions (!)
7) Alcoholic beverages
8) Over-eating in general
9) Beware of the candy dish!

(1) C H O C O L A T E

The toxicity of chocolate is dose-dependent; in other words, a large dog eating a small amount of chocolate is not likely to have any trouble. However, a small dog eating a large amount of chocolate may become seriously ill or even die. Baker's chocolate (pure, unsweetened chocolate or cocoa powder) is the most dangerous. Chocolate to which milk or other ingredients have been added is less toxic. The toxic substance which chocolate contains is called theobromine, a compound which is very similar to caffeine. Smaller quantities of chocolate may cause only a little hyperactivity, similar to what we might experience if we drank a bit too much coffee. In toxic quantities, chocolate causes vomiting, rapid and sometimes irregular heartbeats, muscle tremors, and even death. The amounts of chocolate that are toxic are as follows: (1) for milk chocolate, approximately 1 oz. per pound body weight is toxic; (2) for bakers chocolate, only 1/10 oz. per pound is toxic. There are also individual variations among dogs. In addition to the toxicity of the theobromine in chocolate, the foods in which chocolate is found tend to be rich in fat. Excessively fatty foods are prone to cause pancreatitis, a serious, sometimes life-threatening inflammation of the pancreas, which is the organ that produces digestive enzymes and also contains the cells that produce insulin. Even if a dog survives an attack of pancreatitis, long term sequellae may include digestive enzyme deficiency and/or diabetes (in which high blood sugar is caused by a lack of insulin). For more information on this dangerous syndrome, please refer to the vet@dog article entitled "Holiday Decorations: physical hazards." If your dog does eat chocolate-containing foods or candy, first find out the kind of chocolate that was consumed (i.e. pure dark chocolate, milk chocolate, or chocolate flavored baked goods). If you feel comfortable estimating the toxic amount for your particular dog and believe that the dog consumed significantly less than a toxic amount, you may not need to do anything other than monitor for minor GI upsets common with any abrupt change of diet. However, if there is any doubt as to the content of the chocolate in the food, or you are unsure of your calculations, consult your vet, an emergency hospital, or the Animal Poison Control Center as soon as possible. If the chocolate was consumed within the past hour, it might help to induce vomiting, but consult your vet first. Earlier consumption might require intensive treatment at an emergency facility. If your dog is showing signs of agitation, heavy panting, muscle tremors, vomiting, hyperactivity, or even marked lethargy, consult a veterinarian right away.

(2) R I C H , F A T T Y F O O D S

Rich, fatty foods, such as turkey skin, bacon, sausages, hot dogs, fruit cake, plum pudding, or deep-fried foods can be quite dangerous to dogs susceptible to attacks of pancreatitis. Often you may not know that your dog is susceptible until he is very sick with his first attack. As breed predispositions go, it is often the smaller, more energetic breeds like miniature or toy poodles, cocker spaniels, miniature schauzers, and other small terrier-type dogs who seem particularly prone. However, any dog may have a problem. It is best to avoid these foods altogether. Signs of pancreatitis generally include an acute onset of vomiting (sometimes with diarrhea) and abdominal pain, which may be evidenced as a hunched posture or "splinting" of the abdomen when picked up. The dog may become very sick quickly and often needs intensive fluid and antibiotic therapy. For an additional discussion on this topic, refer to the topic on "Physical Hazards".

(3) D A I R Y P R O D U C T S

Dairy products are not generally dangerous, unless they contain a lot of fat (see discussion on pancreatitis), but they are usually digested poorly by both dogs and cats, who have little or none of the enzyme required to digest the lactose in milk. Just like lactose-intolerant people, lactose-intolerant dogs can develop excessive intestinal gas (flatulence) and may have foul-smelling diarrhea. It is best to avoid most dairy products altogether, although small amounts of cheese or plain yogurt are tolerated by most dogs, since these products have less lactose than most.

(4) R A W H I D E S, C O W H O O V E S, & P I G S ' E A R S

These well-liked dog treats are purchased in large numbers, especially around holidays, by well-meaning dog owners hoping to give their pets something special. These toys are favorites for many dogs and are popular with owners because they keep their pets occupied and supposedly out of trouble during holiday activities. There are definite risks associated with these treats, however. All three types are supposedly made of digestible animal products. However, they are digested quite slowly and, if consumed rapidly, can cause either vomiting or diarrhea from the many pieces still sitting undigested in the GI tract. If the treats are swallowed whole or in large chunks, there are additional dangers. Rawhide chews can lodge in the throat and cause choking, or a large piece may be swallowed, scraping and irritating the throat and esophagus on the way down. Once in the stomach or intestinal tract, a large piece of rawhide can also create a physical obstruction. An additional danger that is less widely known is the practice, in some countries, of using an arsenic-based preservative in the processing of rawhide toys. We recommend that, if you do purchase these products, stick to brands processed in the U.S. There has also been a recent FDA alert about the risk of Salmonella accociated with dog chew products made from pork or beef-derived materials: refer to the FDA advisory or call 1-888-INFO-FDA. See below (discussion on pigs' ears) for more details.

Cow hooves are even more dangerous than rawhides. They are hard enough that a dog can actually break a tooth on one. They can also be chewed up into sharp fragments which may cause a partial intestinal obstruction. Partial obstructions are often difficult to diagnose until the point at which the fragment is ready to perforate the wall of the bowel from pressure against the sharp edges. If perforation has occured, the infection that ensues from leakage of intestinal contents can be fatal.

Pigs' ears can cause GI upset if overeaten, similar to the situation with rawhides, although obstructions are less common because the ears are not usually shaped into solid chunks. There is, whowever, a less widely known danger associated with pig ears: A recent FDA advisory published by the U.S. Dept. of Health and Human services on Oct.1, 1999, stated that there is "a nationwide public health warning alerting consumers about a number of recent cases in Canada of human illnesses apparently related to contact with dog chew products made from pork or beef-derived materials (e.g., pigs ears, beef jerky treats, smoked hooves, pigs skins, etc.)... FDA is urging pet owners... to handle them carefully. Anyone who comes in contact with these treats should wash their hands with hot water and soap. Initial reports of illnesses came from Canada and involved Canadian products, but subsequent examination of similar products produced in the U.S. indicate that all pet chew products of this type may pose a risk...."

(5) B O N E S

Most bones are dangerous treats to give to dogs. Turkey, chicken, pork, and beef rib or steak bones are the worst. These bones are all easily chewed into sharp splinters that can lodge in the GI tract and may cause esophageal or intestinal lacerations, partial or complete obstructions, or even perforations with subsequent life-threatening peritonitis. The only type of bone that is safe for dogs to chew on is a beef shin bone, preferably the type that is commercially processed. These have been sterilized and the marrow has been removed. The shin bone is the long, tubular bone without the rounded ends, which are softer than the cylindrical part and can easily be chewed off and swallowed. If you decide to purchase shin bones yourself from a meat market, buy the ones that are at least 8 inches long. Then boil them long enough to remove the marrow (which can cause diarrhea because of its high fat content); let the bones dry thoroughly and then store them in the freezer, not the refrigerator. Refrigerated bones can become soft enough for a dog to chew off pieces that can be swallowed. One more word of warning: if your dog has swallowed any bones that can spinter, do NOT induce vomiting, because they could cause an esophageal laceration on the way out. Please refer to last week's topic on what to do if your dog chews glass ornaments for information on ways to handle sharp objects that have been ingested.

(6) O N I O N S !!!

Most people do not realize that onions can actually be toxic to dogs and cats (especially cats) when consumed in large quantities. There was an article in a prominent veterinary journal several years ago about a cat that actually died from eating onion soup (which has a high concentration of onions in it)! Small amounts of onion are not a problem for most animals, but large quantities cause some changes in the red blood cells (which are the blood cells that carry oxygen) such that they cannot perform their usual function. The individual cells acquire a structural defect called Heinz bodies that make the body think the cells are defective and remove them from circulation. The resulting anemia (=deficiency in oxygen-carrying red blood cells) is called Heinz body anemia. Another reason not to give onions is that the foods that contain them are often rich and fatty (e.g. fried onion rings, onion gravy, turkey stuffing with onions) and rich foods may bring on an attack of pancreatitis [see #2 above].

(7) A L C O H O L I C B E V E R A G E S

It may seem odd to include these in our list of treats, but you would be surprised to know the number of dogs who manage to drink these beverages, either because some well-meaning owner thinks it is "cute" to offer a holiday drink to their dog or because some thieving little canine has stolen a few laps from a drink left on the coffee table! Dr. Pinkston's very own Labrador retriever, years ago, drank an entire Kalhua and Cream at a staff Christmas party and slept through the entire party. She also had a client who was panicked at what they thought was a bizarre neurological disease in their Golden retriever, only to realize that there had been some left-over drink cups from a party the night before and the dog had "indulged" without their knowing it. Although alcohol itself is not particularly toxic to dogs (except in really excessive amounts), their tolerance to its effects is very low. Pound for pound, a dog gets "drunk" on far less alcohol than a human of the same weight. It is wise to exercise caution when consuming alcoholic beverages around pets.

(8) O V E R E A T I N G I N G E N E R A L

The holiday "pig out" is not just confined to people. There are many instances of dogs doing the same thing, either because some owners want their dogs to have their share of holiday goodies or because the dogs have stolen some goodies of their own. As discussed above, some of these goodies are rich enough to cause pancreatitis in susceptible individuals. However, overeating, coupled with excitement, exercise, and/or excessive water drinking, can cause a life-threatening condition (primarily, but not exclusively in large breed dogs) called "gastric dilatation and volvulus" syndrome, known more commonly as "Bloat." We will discuss this syndrome in detail in a future issue of vet@dog, but you should learn the symptoms, so that you can call an emergency facility IMMEDIATELY if you see the symptoms. Typical signs are (1) a distended abdomen, which, when thumped with a finger, sounds like a tight, air-filled drum; (2) intense abdominal discomfort (possibly seen initially as a very "preoccupied" look on the dog's face; (3) non-productive retching or vomiting; and (4) rapid development of severe weakness and shock. This is a rapidly life-threatening emergency. You MUST contact your veterinarian or emergency clinic IMMEDIATELY.

(9) T H E C A N D Y D I S H O N T H E C O F F E E T A B L E !

Last, but not least, do NOT leave candy dishes on the coffee table! Even small dogs are very creative in figuring out ways to get on a low table and decimate the candy supply. If some of this candy is chocolate, this can be a very dangerous situation (see above). Even nuts, although not toxic, can cause a pretty severe (or at least messy) GI upset from the change in the dog's regular diet. Use common sense when leaving out dishes and trays of food. Never underestimate your dog's ability to ferret out food when given half a chance!!

vet@dog feedback: Selected questions from readers:
» Q: A man who is splitting up with his live-in girlfriend asked if it is fair to separate their two 1 1/2 yr old pugs, who grew up together.

» A: It depends upon how bonded the two dogs are to each other. If the dogs are used to doing things separately with the individual owner(s), then separating them should not be too traumatic. However, if they are used to being together constantly, they would probably be anxious for a few weeks before they became adjusted to being alone. Most times, however, this period of anxiety can be minimized by giving the dog a lot of human companionship during the transition.

» Q: An owner is concerned that his dog is licking her back legs until they are raw and would like to know what can be done, besides using a cone-type collar to prevent her physically from chewing at herself.

» A: Although there may be aggravating psychological factors that cause a dog to lick and chew at himself, virtually all cases such as this have an underlying skin problem. It is important that the skin problem be diagnosed and treated properly, for an adequate length of time, or this vicious cycle will probably continue. If your veterinarian has not been able to determine an underlying cause, consider requesting a referral to a veterinary dermatologist.

copyright & disclaimer
Information and opinions stated are for educational purposes only, should not be used for diagnosis or treatment, and are not intended to replace advice and/or treatment provided by your veterinarian. Dr. Pinkston disclaim responsibility for the consequences of any action you may or may not take based on this information. Please consult your veterinarian for specific advice and treatment of your dog.