Some foods can be harmful to the health of dogs and cats. And during the festive season, it pays to be extra careful. Expert advice.
The dangerous foods for our four-legged friends are not numerous, but they can pose a problem especially during the festive season, when recipes for cakes, sweets and savoury preparations may inadvertently end up in the stomachs of dogs and cats. With advice from Dr Barbara Tonini, a veterinary surgeon with a doctorate in dog and cat nutrition, we have drawn up a list of the foods that can be harmful to our animals' health.
These are two foods that contain substances called methylxanthines, which can cause vomiting, diarrhoea, thirst, excessive urination, hyperactivity, abnormal heart rhythm and tremors that can lead to seizures and even death. Particular care must be taken with dark chocolate, as it contains a high quantity of methylxanthines.
Mild to moderate clinical signs have been observed following ingestion of 20 mg/kg of methylxanthines, with seizures occurring at 60 mg/kg. For this reason, it is advisable to contact a vet even if the dog has ingested only a small amount of chocolate. Poisoning from products containing high quantities of caffeine, such as coffee beans or bitter cocoa, is instead characterised by tachycardia, increased respiratory rate and widespread tremors that can progress to convulsions.
These two fruits can cause kidney failure and, although the toxic substance and the doses responsible for kidney damage are not known, it is never advisable to give them to our four-legged friends.
These vegetables, in addition to causing the typical gastrointestinal symptoms, can lead to anaemia due to damage to the cell membrane of red blood cells. Cats are certainly the most sensitive to developing this type of problem, but dogs that consume large quantities can develop the same condition. Attention should also be paid to the presence of onions or onion powder in puréed baby foods that may be included in the diet of puppies, especially those containing fish, which are often also vegetable-based.
Xylitol is present as a sweetener in chewing gum, sweets, baked goods and toothpastes. Its ingestion in dogs and cats can cause a rise in insulin levels and consequent hypoglycaemia, as well as liver failure. The initial symptoms are vomiting, lethargy, loss of balance and coordination, through to seizures. The elevation of liver enzymes persists for several days and requires supportive therapy under veterinary supervision.
Some types of fish, such as salmon, trout and sturgeon, can contain a parasite that causes the so-called "salmon poisoning disease". The first signs of the condition are vomiting, fever and swollen lymph nodes; if left untreated, the poisoning can be fatal.
Raw meat and raw eggs can be contaminated by bacteria such as salmonella and E. coli, which are dangerous both for dogs and for humans. Furthermore, raw egg contains a protein called avidin that reduces the absorption of biotin, a B-group vitamin whose deficiency can cause skin and coat problems. Finally, giving bones can be responsible for dental damage, intestinal perforations or blockages that require prompt veterinary surgical intervention.
Drinks or foods containing alcohol can cause vomiting, diarrhoea, depression, breathing difficulties and tremors in dogs and cats, and in the most serious cases can lead to coma and death.
Giving milk is not recommended, especially for dogs, because after two months of age the lactases — the enzymes responsible for digesting lactose — are present in very low concentrations, and the failure to digest lactose can lead to bouts of diarrhoea. According to a recent study, the quantity of milk that should be tolerated without causing diarrhoea is approximately 20 ml/kg of body weight of our four-legged friend.
Yeast can ferment and cause gastric dilation in animals. Furthermore, ingestion of raw bread dough can produce ethanol, causing symptoms similar to alcohol poisoning.
Large amounts of salt cause increased thirst in dogs and cats, as well as increased urine output, and in the event of a genuine poisoning, bouts of vomiting and diarrhoea can occur, potentially leading to severe neurological symptoms including tremors and seizures.