Grape poisoning in dogs

Dogs are often fond of fruits and vegetables, especially in summer. If a majority of fruits are well tolerated by the dog, the ingestion of grapes presents a high risk of toxicity which is still too little understood, which can go as far as the death of the animal in the most serious cases. The cause of this acute toxicity, mainly renal, has not yet been clearly identified. And the toxic dose varies greatly depending on the cases reported. Grape poisoning is a real emergency, regardless of the amount consumed, knowing that the first symptoms appear in the hours following ingestion and that the prognosis is linked to the speed of the implementation of the treatments. Here, you will understand about grape poisoning in dogs.

Are all grapes poisonous and in what doses?

All varieties of table grapes or vines, white or black, with or without seeds, can be potentially toxic to dogs. Raisins and derived products such as grape marc or cookies containing grapes are also at risk. Toxicity is possible regardless of the degree of maturity of the grains and the grapes, even fallen to the ground for several days, remain dangerous.

The animal poison control center reports toxic doses ranging from 10 grams to 50 grams of fresh grapes per kg of dog. Lower doses find in some countries such as the United States, where a few grains were enough to poison dogs weighing less than 10 kg. Conversely, dogs having consumed more than 1 kg of grapes did not show any symptoms. A great individual variability thus seems to exist and knowing that, according to the varieties of grape. The average weight of a bunch can vary from less than 100 grams to more than 500. The risk of intoxication is to consider whatever the number of grapes ingested.

Be careful, if the dog has consumed raisins, the potentially toxic dose is even lower, of the order of 4 grams per kg, since the grains have lost part of their weight in water.

What is the cause of grape toxicity?

The exact origin of this toxicity is not yet known. Different substances which can nephrotoxic (that is to say toxic to the kidneys), suspected. They include mycotoxins produced by molds, pesticides, tannins or heavy metals. The mechanism of action leading to the development of acute renal failure is also poorly described.

According to all the cases identified in countries, no predisposition of race, sex or age has been demonstrated.

Clinical manifestations

The first symptoms of grape poisoning in dogs most often appear 6 to 24 hours after ingestion and may persist for several days. These are mainly digestive and general signs:

  • Vomiting (the most typical sign)
  • Diarrhea
  • Nausea
  • Abdominal pain
  • Despondency / Fatigue
  • Dehydration
  • Anorexia

Intoxication progresses over the following days with the development, in the most serious cases, of acute renal failure within 48 to 72 hours; renal failure characterized by typical clinical and biochemical manifestations:

  • Decrease or absence of urine production (oliguria – anuria)
  • Increased drinking (polydipsia)
  • Increased levels of urea, creatinine and phosphorus in the blood
  • Change in other blood parameters such as calcium, liver enzymes or red and white blood cells
  • Presence of protein in the urine or even glucose, blood or crystals
  • Appearance of ulcers in the mouth
  • Hypothermia
  • Coma and death in the most severe cases
Grape poisoning in dogs

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When the consumption of grapes has not voluntary or not observed directly, the diagnosis can nevertheless facilitate if we observe grape remains in the contents vomited by the dog. If this is not the case, the diagnosis can be very difficult because the first clinical signs observed are common to many poisonings and other diseases. Likewise, acute kidney failure that can develop in the days that follow can also have many origins.

Various additional examinations such as blood and urine tests or an ultrasound of the kidneys can refine the diagnosis. But there is no specific test to confirm grape poisoning.

Treatment and prognosis

As in many cases of poisoning, treatment and prognosis will not be the same depending on the speed of intervention after ingestion of the toxicant. As the cause of the toxicity of grapes is not known, there is no specific antidote to administer.

If the treatment will implement within two hours of consuming the grapes, the goal is to make the dog vomit using suitable molecules. Secondly, the administration of activated vegetable charcoal makes it possible to absorb the toxins still present in the digestive tract in order to prevent them from passing into the dog’s bloodstream.

Thereafter, the treatment is essentially based on the administration of fluids by intravenous route to eliminate the toxins passed into the blood of the animal and to oppose the development of renal failure. Renal function should closely monitor due to hospitalizing the animal for at least 3 days and measuring urea and creatinine levels in the blood to best adapt the infusions. Other symptomatic treatments are gastric dressings, antiemetic or anti-acid substances. They can use depending on the clinical signs presented by the animal.

Signs of acute renal failure

If signs of acute renal failure will observe, more specific treatments should consider such as phosphorus chelators. Refeeding the animal is essential to hope for a good recovery and if the dog refuses to eat alone, the placement of a catheter should be considered. Molecules to stimulate urine production as well as the placement of a urinary catheter may be necessary.

The prognosis reserves in dogs which do not produce any more urine at all (anuria). Because this indicates a severe damage to the kidneys. If the dog’s vital prognosis will engage and the treatments implement will not sufficient, peritoneal dialysis, can consider. It considers only in under certain conditions or even hemodialysis. But the latter requires equipment. Peritoneal dialysis is a technique allowing the elimination of toxins from the body. Specific and is therefore only offered in certain specialized veterinary centers.