Chocolate Toxicity In Pets

Chocolate is one of the most common toxicities I see, especially around Christmas and Valentine’s Day. Pets climb counters to get to candy dishes and desserts. They also rip open boxes of chocolates wrapped as gifts. One of my patients, a cocker spaniel, ate a 5 pound box of dark chocolate that was left under the tree.  They found him unconscious on his doggy bed.

Chocolate contains caffeine and theobromine which are toxic to animals.  This fact surprises a lot of people because humans are fairly resistant to this class of drugs. We can drink a lot of coffee and eat chocolate without too many problems. But dogs are much more sensitive to the effects of these chemicals. The half life of caffeine in dogs is 4.5 hours while the half life of theobromine is 17.5 hours!

The amount of these two chemicals varies with the type of chocolate. Milk chocolate contains the least amount of caffeine and theobromine while the bitter chocolate used in cooking contains the most. Dark chocolate falls in between. The general rule that I was taught in veterinary college is the more bitter the chocolate, the more of these chemicals and the greater the danger of poisoning.

Clinical signs of chocolate toxicity depend upon the amount of theobromine and caffeine ingested i.e., the type and amount of chocolate and the size of the pet. A golden retriever who steals a dark chocolate candy bar may show no signs of toxicity whereas a Chihuahua may develop seizures. In general, signs of mild toxicity include an increased heart rate and hyperactivity which many people wrongly attribute to the sugar high.  After the initial rush, some dogs will develop gastrointestinal signs including vomiting and diarrhea. Others drink and urinate excessively. Dogs who ingest large amounts of chocolate often seizure and may die.

Treatment of chocolate toxicity usually starts with ‘decontamination’ which means removing the toxin. If the dog is conscious, vomiting is induced to get rid of as much of it as possible. After the stomach is empty, the dog is given charcoal to absorb the remaining chocolate once they have stopped vomiting. The rest of therapy is tailored to the patient. Seizures are treated with anticonvulsant medications, life threatening ventricular tachycardia is slowed with heart drugs such as lidocaine or propranolol and stomach ulcers are given gastrointestinal protectants. The cocker spaniel mentioned above spent 3 days in the hospital on IV fluids and anticonvulsant therapy. For the first day, diarrhea poured out of his anus.  It looked and smelled like chocolate. He was one of the lucky ones. Unfortunately, he still liked chocolate. His family said he managed to grab a brownie about a week after his ordeal.

If your pet ingests chocolate, contact your veterinarian or the Pet Poison Helpline right away. Have the type of chocolate, quantity of chocolate and weight of the pet ready when you call. The number for Pet Poison Helpline is: 800.213.6680. More helpful information on poison of all kinds can be found at


-Shell, Linda. “Xanthine Toxicosis” VIN Associate, Lasted updated 1/17/2006.



Health For Indoor Cats

Cats are like people, they need regular medical care to remain healthy. But  some people think their cats don’t need annual check- ups because the cats are strictly indoors and don’t act sick. Unfortunately, nothing could be further from the truth. Cats can develop several health problems as they age.

Dental disease is very common. In my experience, almost all cats 5 years and older have some degree of dental disease. Since cats don’t pant, most people won’t notice bad breath as readily as they will in dogs. If ignored, the infection progresses causing pain and damaging the tooth crowns, roots and supportive structures.

Mauka 2 snip

Cats, both indoors and outdoors, also develop hyperthyroidism, kidney disease and gastrointestinal disease. Annual blood and urine tests will catch these problems early when treatment can make the most difference.  Orthopedic and arthritic conditions are also possible as cats age.

Many people are surprised to learn that indoor cats can become infected with parasites. Mice and rats may bring fleas and ticks into the house. If the family dog isn’t on a flea and tick preventative, it can also bring parasites from the yard into the home. Humans may carry parasite eggs inside the house on their shoes. Mosquitos carrying heartworms and flies carrying round worms may enter through open doors and windows. Cats may even get parasites though infected plants and potting soil.


That’s why all cats need annual examinations and preventative care. Although cats kept indoors are much safer than those allowed to go outdoors, they can still develop health problems. Cats are experts at hiding their health problems. To keep cats feeling their best, regular check-ups are needed.

Common Types of Splenic Cancer in Dogs

The spleen is a burgundy colored organ that filters blood. It is found in the abdominal cavity near the stomach. I often feel it when I am performing abdominal palpation.  Unfortunately, the spleen is one of the common places to find cancer in dogs. The following is a list of some of the common tumors (cancers) I see in dogs. Please remember, not all tumors are malignant. Many are benign and respond well to surgical removal of the spleen. Histopathology is required to make a final diagnosis.

  1. Hemangiosarcoma – This is a malignant tumor often seen in middle-aged to older German Shepherds, Labrador Retrievers and Golden Retrievers. Beside the spleen, this aggressive cancer also occurs on the right atrium of the heart and the liver.
  2. Hemangioma – This is a benign tumor that is also seen in middle-aged to older German Shepherds and retrievers, especially Goldens.  Even though the tumor does not spread to other parts of the body like hemangiosarcoma, it can still be very dangerous. These tumors often bleed into the abdominal cavity causing life-threatening anemia. Microscopic analysis is needed to distinguish a hemangioma from a hemangiosarcoma although I have found hemangiomas are usually much larger in size than hemagiosarcomas.
  3. Lymphoma – I often see this cancer occur in the spleen along with lymph nodes throughout the body.
  4. Mast Cell Tumors – Mast cell tumors tend to spread quickly throughout the body and often affect the spleen.
  5. Many other tumors can occur in the spleen although not as commonly as the ones listed above. Bernese Mountain Dogs and flat-coated retreivers often get histiocytic sarcomas of the spleen. I have also seen plasma cell tumors and a variety of other  tumors including leiomyomas, fibrosarcomas, melanomas and nerve sheath tumors.
Splenic mass on right side of spleen with attached omentum
Splenic mass on right side of spleen with attached omentum


-Shell, Linda (Original author), Intile, Joanne (Revision Author). Splenic Neoplasia. Associate, Veterinary Information Newtwork, Originally posted 3/29/2006. Updated 3/6/2015.