Parvo is one of the most common causes of infectious diarrhea in young dogs. It is a devastating virus that can survive for many months in the environment and is difficult to destroy. It is most severe in young, rapidly growing pups that also harbor intestinal parasites (worms, coccidia, Giardia). It is highly contagious and easily transmitted through contaminated feces. It causes severe gastrointestinal signs (diarrhea, vomiting, dehydration, depression) and can also affect the heart muscle resulting in sudden death. The intestines become severely inflamed resulting in a condition called enteritis. Vaccinated females will provide protection (maternal antibodies) in the milk for their pups. This protection, however, inhibits the ability of the pup to develop its own protection in response to vaccination. At weaning, the maternal antibodies will gradually decline resulting in less protection, but allowing the pup to gradually respond to vaccination. The first vaccination takes at least a week to provide some protection, while booster vaccinations are necessary to provide increased levels of protection. These factors create a “window of susceptibility” to infection – maternal protection is gone and vaccine protection hasn’t developed. This is one of the reasons Parvovirus can still occur in spite of proper husbandry conditions. With the new high-titer, low-passage vaccines, the “window” is greatly reduced (but still present).

Heartworms (Dirofilaria immitis) are a blood parasite transmitted to dogs by many species of mosquitos. A female mosquito picks up larvae while feeding on an infected dog. The larvae develops in the mosquito and is then transmitted to another dog when the mosquito feeds again. The larvae then develops further and migrates to the heart of the dog to live as an adult. Signs include exercise intolerance, coughing, and difficulty breathing. Diagnosis requires a blood test. Treatment is a delicate procedure and involves killing the adult worms in the heart and killing the larvae in the bloodstream. However, a dead adult worm can drift through the arteries and become lodged in the lungs causing complications and even death. Thus, the treatment regimen must be closely monitored by a veterinarian. Prevention involves monthly medication designed to kill the larva, but should only be used after a negative blood test. If adult worms are present, the preventative could kill them also, resulting in unexpected and adverse side effects. Consult your veterinarian for accurate diagnosis, prevention, and treatment.

An open fontanelle is a soft area, present on the top of the skull.  It remains in the incompletely ossified (bone tissue not completely formed) skull of a developing puppy.  This condition occurs in human infants and is commonly called a “soft spot". The skull is actually made up of several separate bone plates that become fused together during embryonic development.  These bones start out very small and separated.  They gradually grow around the brain and encase it as they meet and fuse together.  Four of these bones meet up at the center top of the skull with this center being the last open space to fill in with bone tissue.  This space is known as a fontanelle.  This space usually fills in slowly after the birth of the pup.  The size and frequency of open fontanelles varies with breeds (common in small breeds and brachycephalic –“flat-faced”- breeds) and the genetics of individuals (an inherited condition).

Open fontanelles, if excessively large, can create two possible problems.  This soft area leaves the brain unprotected by bone and can be a place for a brain injury to occur.  The other potential problem is hydrocephalus, also known as “water-on-the-brain”.  Hydrocephalus is an abnormal accumulation of fluid in the brain cavities causing neurologic problems.  Large open fontanelles are occasionally, but not always, associated with hydrocephalus.  For these reasons, large open fontanelles can create concern for the future health of the pup.