Mixing Litters: A Bad Idea?

Disease Transmission

All litters should be isolated from other animals while monitoring for any developing symptoms. It is not uncommon for kittens to infect each other with diseases such as calicivirus, herpesvirus, feline panleukopenia, FeLV, FIV, and others. For puppies, there are also risks of transmitting parvovirus, distemper, and other illnesses.

Parasite Contamination

Whether external or internal, parasites spread easily between animals. It is common for rescued kittens and puppies to be full of worms, which can affect their digestive system for some time. Appropriate treatments are therefore essential before allowing contact with other animals, and a period of isolation is necessary during the first weeks of care.

Rejection or Overload

Some mother cats may reject newcomers, push them away, or even injure them. If they already have many babies or fragile health, adding more mouths to feed can exhaust them. Added kittens may be stronger or weaker than biological ones, which can lead to malnutrition or growth delays in some.

Conclusion

Although mixing kittens and puppies requires less human management (since the mother nurses the babies) and can generally be positive for socialization, it remains highly risky. Some shelters face outbreaks that endanger the animals' lives and strain the organization’s finances.

Orphaned newborns are therefore safer when placed together with an experienced caregiver who can feed them and substitute for their mother. Once their isolation period is over, introducing them to sociable adult cats helps promote their development.

One step at a time: preventive isolation, then socialization.