• Crababple trees not good for dogs."Pluto my English mastiff puppy of ..." is Copyrighted by Flickr user: claudiogennari under the Creative Commons Attribution license.
  
  

Toxins

• The crabapple tree's seeds, leaves and stems contain cyanogenic glycosides. Chewing and ingesting them causes cyanide to be released. Cyanide can cause cell death very quickly.
  
  

Toxicity Level

• Crabapple seeds are rated as a Class 1 toxin. Class 1 is major toxicity, meaning they may cause serious illness or death if ingested.
  
  

Size

• Toxicity level depends on amount ingested and size of the animal. A few bites eaten by a small dog can be fatal, whereas a large breed dog would not show any symptoms even though it isn't healthy to eat any of it.
  
  

Symptoms

• Symptoms of cyanogenic glycoside poisoning include vomiting, diarrhea, congestion, slowed heart-rate, seizures and death. Although more common in livestock that consume large amounts, dogs who eat crabapples can get sick or die.
  
  

Prevention

• Fence off dangerous trees."Lock it Up" is Copyrighted by Flickr user: fotographix.ca (Jesse Yardley) under the Creative Commons Attribution license.
  
  Most dogs do not eat crabapples or the foliage. Watch your dog for any indications of eating on the trees. If you see this, supervise the dog when out, remove the tree or put fencing around the tree to keep the dog from getting to it.