Causes of fading puppy and kitten syndrome - Veterinary Medicine
Medicine Center
DVM Veterinary Medicine Featuring Information from:


Causes of fading puppy and kitten syndrome
Getting a grasp on the many things that can prove fatal in puppies and kittens can help you save these neonates struggling for their lives.


Neonatal alloimmune hemolyticanemia in cats

Table 1. Prevalence of Blood Type B in Selected North American Cat Breeds*
Because of endotheliochorial placentation, almost no placental transfer of antibodies occurs in bitches or queens. Essentially all passive antibody transfer occurs through absorption of colostrum in the first 12 to 24 hours postpartum.21,22 In cats, this also presents the risk of early death due to neonatal alloimmune hemolytic anemia. Cats have two main blood types, A and B, with a rare occurrence of AB. In North America, most domestic shorthaired cats are type A, with only 1.7% to 4.7% exhibiting type B.1 Various purebred cats have a higher prevalence (19% to 59%) of blood type B (Table 1).1,7

Heterozygous type B queens bred to type A toms can produce type A kittens. Since all type B cats have circulating anti-A antibodies, ingestion of colostrum by these kittens will result in acute alloimmune hemolytic anemia and severe illness or death. Clinical signs and laboratory findings include failure to thrive, dark-red-brown urine, and anemia; acute death also occurs.1


Table 2. Infectious Causes of Fading Puppy and Kitten Syndrome*
Bacteria, viruses, and intestinal parasites can all cause or contribute to fading puppy or kitten syndrome (Table 2).

Bacterial infection

Neonatal septicemia results from systemic bacterial infection. Because of their immature immune systems, puppies and kittens are at risk for infection through the placenta, umbilicus, or gastrointestinal or respiratory tract from contaminated environments. Dams with postpartum metritis or other bacterial infections may act as a source.18 Gram-negative organisms are most commonly isolated, but Streptococcus and Staphylococcus species can be involved, particularly in kittens.18,23 Group B streptococcus has been identified as a cause of death in neonatal puppies.24 Brucella canis can cause neonatal puppy death as well as fetal loss. Clinical signs of sepsis vary but include vomiting, diarrhea, constant crying, fever, failure to nurse, and sloughing of the ear and tail tips and toes. Hypoglycemia often occurs with septicemia.18,25

Viral infection

Viral infections are a common infectious cause of neonatal losses in dogs and cats.1,4


In puppies, canine herpesvirus infection is a frequent cause of neonatal morbidity and mortality.26 Herpesvirus is a mild endemic respiratory virus in adult dogs, but it causes abortion and early neonatal death when contracted by a bitch during the last three weeks of gestation and neonatal illness and death when pups are exposed in the birth canal or during the first three weeks of life.23 Clinical signs include constant crying and abdominal pain; acute death also occurs. Necropsy reveals petechiation of the kidneys, liver, and intestines, and infection is confirmed with virus isolation.27 Nested polymerase chain reaction testing has also been used to document canine herpesvirus infection and is available from a number of sources.28**

A canine herpesvirus vaccine is available in Europe but not in the United States. In a challenge study with six vaccinated and six control bitches, the vaccinated bitches developed high titers to canine herpesvirus, lost no pups to canine herpesvirus infection, and had higher pregnancy rates and lower neonatal mortality than did control bitches.29 Control bitches lost 62% of pups to canine herpesvirus infection.29

Infection with canine parvovirus type 1, also known as minute canine virus, presents a similar picture, with rapid onset of crying, failure to nurse, vomiting, diarrhea, dyspnea, weakness, and sudden death at 5 to 21 days of age.30 Diagnosis depends on isolating the virus, which must be done with a particular cultured cell line that may not be available at all laboratories.***


Click here