Neonatal and Pediatric Health

Some of the neonatal and pediatric conditions currently being monitored by the Neonatal and Pediatric Committee.

Please see the information about the importance of necropsies on any lost neonatal or pediatric puppies. Please review and print the simple necropsy checklist to have available at your time of need.

Microphthalmia Syndrome (MO) previously known as Puppy Eye Syndrome is a syndrome presenting with multiple signs, including more body systems than the eyes, and has been reported in the Portuguese Water Dog dating back more than 20 years. The mode of inheritance is currently unknown. This syndrome is present at birth and can present with a variety of signs and symptoms. Commonly, neonates present as “failure to thrive” and breeders may be unaware of this condition as the cause unless stillborn and “failure to thrive” puppies that do not survive have a post mortem exam (necropsy) performed. Affected puppies that survive past weaning typically have a shortened life span with a variety of health problems reported.

This syndrome exhibits eye-related conditions which are best diagnosed by a veterinary ophthalmologist after the puppy is seven weeks of age or by necropsy done at Cornell. In addition to these eye conditions, these neonates or pediatric puppies may exhibit one or more of the following signs:

  1. “Failure to Thrive” – These pups have been reported to have either normal or less than normal birth weights. Some are weak, poor nursers, and fail to gain weight. They may not grow at the same rate as their littermates and may require hand feeding. Because of this, they are more likely to develop aspirational pneumonia.
  2. Puppies may appear normal until 3-4 weeks of age, at which time they may seem clumsier and get lost easily, often due to vision problems.
  3. Puppies may have difficulties transitioning from nursing to solids. Once eating, they may gorge themselves and make unusual vocalizations (chirp) while eating.
  4. Puppies may exhibit weakness in rear legs and difficulty walking and some puppies may be unable to control urination (incontinence).
  5. Affected puppies often have low platelet counts, or thrombocytopenia. Platelets are involved in the ability of the body to stop or prevent bleeding by the formation of blood clots. Dysfunction or low levels of platelets predisposes to bleeding which has been reported in affected puppies.
  6. Eyes may appear smaller than normal (micropthalmic) or in some cases may appear swollen and larger than normal.

Eye conditions associated with this syndrome are best diagnosed by a veterinary ophthalmologist, which can be done as early as eight weeks of age. Reported eye conditions include:

  1. Microphthalmia – compared to other pups in the litter these pups will have small eyes.
  2. Glaucoma – abnormal eye pressure – these pups are often very fussy due to the discomfort associated with this condition and they may have bulging eyes (Please note that this should not be confused with neonatal conjunctivitis (Ophthalmia neonatorum) which is a treatable infection that occurs prior to eye opening in neonatal puppies). This is why it is important for veterinary evaluation of any neonatal or pediatric PWD with an eye problem.
  3. Cataracts
  4. Other eye anomalies such as anterior segment dysgenesis, persitant puppilary membranes, lack of pupils or complete absence of eye parts. Some of these findings may be seen only on post-mortem pathology.

Microphthalmia Research

UPENN (MO) DNA Research Form
Necropsy Information
Necropsy Checklist

If you suspect a pup in your litter has this syndrome, please contact the Chair of the Neonatal Committee. Research for the mutated gene has been funded by the PWDCA and the PWDF and is currently underway at the University of Pennsylvania (UPENN). Necropsies are currently being done for this research at Cornell. Please send euthanized or suspicious puppy deaths for necropsy (autopsy or post-mortem examination) to Cornell. It is also highly recommended to have a board-certified veterinary opthalmology evaluations of the litters before placing puppies in their new homes as some inherited eye diseases, including Microphthalmia Syndrome (MO), can be detected at an early age.

Lymphedema is an abnormal accumulation of lymph which is derived from the fluid between the cells of the body. Puppies severely affected with this condition have also been described as “walrus puppies,” “water puppies,” or anasarca, which is a term used to describe severe, generalized edema. More mild cases typically involve one or more legs, most commonly the hind legs. The swelling starts near the toes and moves towards the body. When depressing the skin with your finger it will cause an indentation that will remain for some time after the release of the pressure (pitting edema).  In severe cases, swelling is generalized over the entire body (anasarca), a form that is often fatal shortly after birth and a condition that commonly result in a need for an emergency C-section due to difficult in passing through the birth canal.

Lymphedema has been reported in the scientific literature to occur in a variety of species including humans, horses, pigs, cows, cats, and dogs, with a variety of breeds reported such as Bulldogs, Poodles, and Labrador Retrievers. In other species, this has also been referred to as “hydrops”.

The diagnosis of primary congenital lymphedema is based on clinical signs and veterinary evaluation. The diagnosis is often made based on characteristic clinical signs and presentation. Skin biopsies can assist with confirmation of the excessive fluid accumulation; however, the anomaly in the lymphatic system cannot be identified with a skin biopsy alone. Diagnostic tools to further evaluate the lymphatic system such as contrast lymphangiography have been performed in a small numbers of dogs with lymphedema but are not readily available. Lymphoscintigraphy, magnetic resonance imaging (MRI), computerized tomography (CT), and doppler ultrasound are also additional diagnostics that have been reported to evaluate the lymphatic system of patients with lymphedema, however, these are most commonly utilized in humans rather that veterinary patients with this disorder.

Primary lymphedema was noted to occur in a family of Poodles and was studied by researchers at the University of Pennsylvania in the 1960s. In that study, primary lymphedema was reported to be inherited as an autosomal dominant disease with variable expressivity (incomplete penetrance) in that family of Poodles. The disorder has been reported in the veterinary literature to be an inherited disease in a variety of dog breeds with suspected autosomal dominant with incomplete penetrance as well as autosomal recessive modes of inheritance. However, in most other dog breeds where this disorder has been described, the exact mode of inheritance has not been thoroughly evaluated. Several candidate genes have been identified in humans as well as other species where inherited primary lymphedema has been described; however, there are no current ongoing research projects involving this condition in dogs.

The difficulty with lymphedema in the dog is that there can be variable expression of the disorder in affected animals in both the severity of clinical signs as well as the age of onset, so that some affected dogs may be easily be overlooked. In some cases, signs of edema may be so mild and improve with age that a puppy is not noticed to be affected with the condition and may unknowingly enter a breeding program. It is important for Portuguese Water Dog breeders and owners to be informed about this disorder. Any puppy or adult Portuguese Water Dog that is suspected to be affected with lymphedema should be evaluated by a veterinarian familiar with this disease in an effort to appropriately identify affected animals. Additional examination of relatives of suspected affected animals is also important to better characterize this disease so that care can be taken to avoid perpetuation of the inherited form of this disorder in the gene pool.

PWD owners and breeders who have a dog diagnosed with lymphedema (or relative) are encouraged to contact the PWD Pediatric and Neonatal Health Committee as well as consider submission of DNA to the Canine Health Information Center’s DNA Repository ( for potential use in future research.

Why PWDCA is addressing this:

Both Microphthalmia Syndrome(MO) and Lymphedema affect the lifespan and quality of life of Portuguese Water Dogs.


Please see the information about the importance of necropsies (post mortem examinations) on any lost neonatal or pediatric puppy and please contact the chair of this committee is you suspect a pup in your litter may be affected with a health condition.

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