Dear Christopher Cat: We live in the country, and our cats play outdoors in the gardens during the day. Our newest cat, Clyde, occasionally chews on the shrubs around the house, including the azaleas, rhododendrons and yews. Are these plants safe?

Christopher responds: Any ingested plant material can cause gastrointestinal problems, including loss of appetite, drooling, vomiting and diarrhea.

But azalea, rhododendron, laurel and yew are particularly toxic to pets. If enough of the plant is ingested, death can occur.

These plants contain toxins that cause cardiac and neurologic problems manifested by weakness, breathing trouble, trembling, loss of coordination, seizures and collapse.

Yews are particularly dangerous. Veterinary medical journals contain reports of dogs that chewed yew branches and died of heart failure before other clinical signs were evident. Humans have even used yew toxins to commit suicide and as chemical weapons during warfare.

The dried plants retain their toxicity for months, so burn or bury plant material after you prune or remove the shrubs.

Encourage Clyde to stay indoors by placing cat perches adjacent to windows that look out on birdbaths, feeders and nesting boxes.

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Dear Daisy Dog: Our golden retriever Clyde was spitting up, so we took him to the veterinarian, who diagnosed megaesophagus. The vet is doing more tests, but for now is having us feed him on the stairs and then stand him up on his hind legs for 10 minutes after he eats. I know the name means large esophagus, but I'd appreciate more information about this disease.

Daisy responds: The esophagus is the muscular tube connecting the mouth to the stomach. When the esophageal muscles are too weak to propel food to the stomach, food sits in the dilated, flaccid esophagus and may return to the mouth, where it's spit out. This passive process, called regurgitation, is the most common sign of megaesophagus.

Regurgitation is very different from vomiting, an active process that involves retching and abdominal contractions. Vomited food is brought up from the stomach and duodenum, the first segment of the intestines.

Megaesophagus can be a primary disease or it may occur secondary to another condition, such as myasthenia gravis, Addison's disease (hypoadrenocorticism) or hypothyroidism. If your veterinarian's testing identifies an underlying disorder, treating it should help.

Nevertheless, management of megaesophagus includes feeding Clyde in a vertical position, with his spine perpendicular to the floor, and maintaining that posture for 10 to 30 minutes after the meal, so gravity helps move food to the stomach.

Many families make or purchase a Bailey chair to keep the dog comfortably upright. See groups.yahoo.com/group/megaesophagus/ for a photo and to join the canine megaesophagus support group.

Small, frequent meals usually help. Your veterinarian may have you experiment with different kinds and consistencies of food to determine what works best for Clyde.

Any food that gets inhaled into the lungs can cause aspiration pneumonia, a life-threatening condition. Call your veterinarian immediately if Clyde develops lethargy, breathing changes, coughing or other difficulties.

Ask the Vet's Pets appears Fridays in the print edition of the Reading Eagle. The animal authors of the column live with Lee Pickett, V.M.D., who practices companion animal medicine. Contact them at www.askthevetspets.com.