Flat-faced dogs often struggle to breathe easy

biology: The study of living things. The scientists who study them are known as biologists.

brachycephalic: A term for skulls that are relatively broad and short. Typically, this type of skull will be at least four-fifths as wide as it is long. In some pets, such as pugs and bulldogs, this smooshed-in face can impair with the airways, making it hard for an animal to breathe. Where loud, heavy breathing occurs (and sometimes choking while drinking water), veterinarians will often recommend that a dog get corrective surgery if possible.

breed: (noun) Animals within the same species that are so genetically similar that they produce reliable and characteristic traits. German shepherds and dachshunds, for instance, are examples of dog breeds. (verb) To produce offspring through reproduction.

canine: Members of the biological family of canids. These are carnivores and omnivores. The family includes dogs, wolves, foxes, jackals and coyotes. (in anatomy) The pointed tooth in a mammal that separates its incisors from its premolars. These canine teeth tend to be especially long in carnivores.

gene: (adj. genetic) A segment of DNA that codes, or holds instructions, for a cell’s production of a protein. Offspring inherit genes from their parents. Genes influence how an organism looks and behaves.

risk: The chance or mathematical likelihood that some bad thing might happen. For instance, exposure to radiation poses a risk of cancer. Or the hazard — or peril — itself. (For instance: Among cancer risks that the people faced were radiation and drinking water tainted with arsenic.)

skull: The skeleton of a person’s or animal’s head.

syndrome: Two or more symptoms that together characterize a particular disease, disorder or social condition.

veterinarian: A doctor who studies or treats animals (not humans).

veterinary: Having to do with animal medicine or health care.