Veterinary spending is subject to few of the perversities that either left or right suppose to be the main problems afflicting health care spending. Consumers pay full frieght most of the time. They are price sensitive, and will let the patient die if keeping him alive costs too much. There is no adverse selection. There is no free riding on mandatory care. Government regulation is minimal. Malpractice suits are minimal, and have low payouts. So why is vet spending rising along with human spending?
Two reasons, presumably: technological change and rising income. As we get wealthier, we spend more of our income on former luxuries, like keeping our pets healthy--nineteenth century veterinary care for sick cats consisted of a sack and some stones to weight it down with.