Foster puppies get sick more often than adult foster dogs. That is not a reason to avoid fostering them. It is just something every puppy foster needs to know going in. Puppies come out of shelter environments with developing immune systems, incomplete vaccine series, and exposure to whatever was circulating in the kennels before they arrived in your home. Some of them will get sick. The question is not whether it will happen, but whether you will know what to look for and what to do when it does.
This post covers the most common illnesses in foster puppies, the signs to watch for, and exactly what to do when something seems wrong.
The Most Important Thing: Act Fast
Puppies decline faster than adult dogs. A puppy who seems mildly off in the morning can be in serious condition by evening if something is actually wrong. This is not meant to be frightening. It is meant to make clear that waiting to see how things develop is not always the right call with a young puppy. When in doubt, contact your rescue coordinator. That is what they are there for, and they would always rather hear from you early than late.
With a puppy, erring on the side of calling too soon is almost never a mistake. Waiting too long sometimes is. When something feels off, make the call.
What Memphis Animal Services Covers
Before getting into specific illnesses, it is worth being clear about this: MAS covers veterinary care for foster animals. If your foster puppy needs to be seen by a vet, that is not your financial responsibility. What you are responsible for is recognizing that something is wrong and communicating with your coordinator promptly so they can direct you to the right care. Do not delay calling because you are worried about the cost. The cost is handled.
Signs That Something Is Wrong
Knowing the baseline normal for your puppy makes it much easier to recognize when something has changed. In the first day or two after placement, take note of your puppy’s energy level, appetite, bathroom habits, and general demeanor. That baseline is what you are measuring against going forward.
Contact Your Coordinator Right Away If You See Any of These
- Vomiting more than once or twice, or vomiting with blood
- Diarrhea that is watery, very frequent, or contains blood or mucus
- Complete refusal to eat for more than 24 hours in a puppy under 12 weeks, or 48 hours in an older puppy
- Lethargy that feels different from normal sleepiness, a puppy who will not get up or engage at all
- Pale, white, gray, or yellowish gums
- Labored or unusually rapid breathing
- Swollen or painful belly
- Seizures or loss of coordination
- Any sudden and significant change in behavior or responsiveness
The Most Common Illnesses in Foster Puppies
Parvovirus
Parvo is the illness puppy fosters fear most, and for good reason. It is highly contagious, moves fast, and is potentially fatal in young puppies who are not fully vaccinated. It spreads through contact with infected feces and can survive in the environment for months.
Signs to watch for
Severe lethargy, complete loss of appetite, vomiting, and profuse bloody diarrhea with a distinctive foul odor. Symptoms typically appear three to seven days after exposure and progress quickly. If you see this combination of signs, this is an emergency. Contact your coordinator immediately and do not wait for symptoms to worsen.
A puppy who has completed their vaccine series has strong protection against parvo. A puppy who is mid-series, which is the situation for most newly placed foster puppies, has partial protection. Keep parvo risk in mind when deciding where to take your puppy. Avoid dog parks, pet store floors, and areas frequented by unknown dogs until the vaccine series is complete.
Kennel Cough
Kennel cough is extremely common in shelter dogs of all ages and very commonly shows up in foster puppies in the first week or two after placement. It is the canine equivalent of a chest cold: uncomfortable and contagious but rarely dangerous in otherwise healthy puppies.
Signs to watch for
A honking or hacking cough, sometimes described as sounding like the puppy has something stuck in their throat. It may be accompanied by a runny nose or mild lethargy. The cough can be triggered by excitement, exercise, or drinking water. In most puppies kennel cough resolves on its own within one to three weeks with rest. Contact your coordinator so they are aware, and keep the puppy away from other dogs during this time since it is easily spread through the air and direct contact.
Watch closely for any progression to labored breathing, loss of appetite, or significant lethargy, which can indicate the infection has moved into the lungs and needs veterinary attention.
Gastrointestinal Upset
Loose stool, mild vomiting, or stomach upset is very common in newly placed puppies for reasons that are not necessarily alarming. A change in food, stress from the transition, or intestinal parasites can all cause GI symptoms that resolve relatively quickly with supportive care.
Signs to watch for
Mild to moderate loose stool or occasional vomiting without blood, in a puppy who is otherwise alert, drinking water, and interested in food. This level of GI upset is often manageable with a bland diet of plain boiled chicken and white rice for a day or two. That said, any diarrhea with blood, any diarrhea that is extremely watery and frequent, or any GI symptoms in a puppy who is also lethargic and not eating should be reported to your coordinator right away rather than managed at home.
Intestinal parasites like roundworms, hookworms, and giardia are extremely common in shelter puppies and are typically treated with dewormers provided by MAS. If your coordinator has not discussed a deworming protocol, ask about it, especially if you are seeing any GI symptoms.
Upper Respiratory Infection
Upper respiratory infections, or URIs, are common in shelter environments and puppies are particularly susceptible. They spread easily through direct contact and shared airspace.
Signs to watch for
Sneezing, runny nose, watery or goopy eyes, mild coughing, and sometimes a reduced appetite. A puppy with a mild URI who is still eating, drinking, and reasonably alert can often be monitored at home with supportive care while you keep your coordinator informed. A puppy whose URI symptoms are severe, whose eyes are significantly swollen or discharge is thick and colored, or who is not eating and very lethargic needs to be seen by a vet. URI in puppies can progress to pneumonia if not treated appropriately.
Hypoglycemia in Very Young Puppies
Hypoglycemia, or low blood sugar, is a specific risk for very small or very young puppies, particularly those under eight weeks or toy breed puppies of any age. It can happen when a puppy misses meals, is too stressed to eat, or is not getting enough nutrition.
Signs to watch for
Sudden weakness, wobbling or loss of coordination, glassy eyes, trembling, or in severe cases seizures or loss of consciousness. This can move from subtle to serious very quickly. If you suspect hypoglycemia, rub a small amount of Karo syrup, honey, or plain sugar water on the puppy’s gums immediately and contact your coordinator or emergency vet right away. Do not wait to see if they improve on their own.
Prevention is straightforward: make sure very young puppies are eating regularly and never go more than a few hours without food. If a young puppy is refusing to eat, flag it with your coordinator early rather than waiting to see if they come around.
What to Do Step by Step
When You Think Something Is Wrong
- Note exactly what you are seeing: symptoms, when they started, how severe they are, and whether the puppy is still eating and drinking
- Contact your MAS rescue coordinator right away, do not wait until the next morning if symptoms seem serious
- Follow your coordinator’s guidance on whether to monitor at home or bring the puppy in for care
- If you cannot reach your coordinator and symptoms are severe or progressing rapidly, contact BluePearl Pet Hospital (901-748-9650),
- Memphis’s 24-hour emergency veterinary clinic, and let MAS know afterward
- Keep the sick puppy away from any other dogs in the home until you know what you are dealing with
- Do not give human medications, supplements, or home remedies without checking with your coordinator or a vet first
Keeping Records
Keep a simple log during the placement of what your puppy eats, their general behavior, and any symptoms you notice. This does not need to be elaborate. A note in your phone with a date and a sentence or two is enough. When you call your coordinator with a concern, being able to say “she started with loose stool yesterday morning and has vomited twice since then, but she ate some of her breakfast today” gives them much more to work with than “she seems sick.”
Also keep the puppy’s vaccination and health records somewhere accessible. Knowing exactly which vaccines have been given and when is essential information for any vet who needs to see them.
If a Puppy Does Not Make It
Most sick foster puppies recover fully with prompt treatment and supportive care. But some do not, and it would not be honest to write a post like this without acknowledging that. Losing a foster puppy is genuinely hard, and it happens to careful, attentive fosters who did everything right. Parvovirus in particular has a high mortality rate in young unvaccinated puppies even with aggressive treatment.
If this happens to you, give yourself time to grieve. It is a real loss. Reach out to your rescue coordinator. They have been through this and they will support you through it. And when you are ready, consider that the care you gave that puppy mattered, that their last weeks were spent in a home with someone who loved them, and that your capacity to do this again is still there when you are ready to use it.
Fostering puppies is one of the most impactful things you can do for the Memphis shelter system. Going in prepared, knowing what to watch for and who to call, makes you a better foster and gives the puppy in your care the best possible chance. You do not need to be a vet. You just need to pay attention and pick up the phone when something seems off.
Memphis Puppies Need Foster Homes Right Now
Puppies are among the most vulnerable dogs in Memphis Animal Services. Foster homes give them the chance to stay healthy, grow, and find a forever family. Apply today.
