Post 2 of Worth the Shot: The Shelter Vaccine Playbook
Not every shelter animal needs every available vaccine. But every shelter does need a clear, evidence-based plan for which vaccines to give, and when.
Some vaccines are non-negotiable for every animal that walks through your door. Others are risk-based decisions that depend on local disease prevalence, animal lifestyle, or age.
And if you remember nothing else after reading this article, I hope you will remember this: NEVER hold an animal back from an outcome in order to receive a vaccination!
Read on to refresh your shelter vaccine knowledge. Let’s start by breaking it down by species.
Essential Intake Vaccines for Dogs and Cats
Dogs entering shelters need immediate protection against the most common and deadly infectious diseases: distemper, adenovirus, and parvovirus (“DAP”). Cats should receive a combination herpesvirus, calicivirus, and panleukopenia – sometimes called HCP or FVRCP- vaccines. Use injectable, modified-live types.
For dogs, an intranasal or oral Bordetella vaccine should also be given at intake.
These vaccines, sometimes called “core vaccines,” start the disease protection clock on day one.
Rabies vaccination of dogs and cats is legally required in most jurisdictions and has significant public health value. However, since it is not a shelter population health concern, rabies does not need to be given at intake but rather should be done before the animal leaves.
Beyond these vaccines, decisions about vaccines get more nuanced, and vaccines described as ‘OPTIONAL’ below are not recommended for every shelter, but are appropriate in some circumstances. Others are straight-up not helpful for a variety of reasons and are not recommended in the shelter environment
How to Make Decisions about Optional Vaccines
Vaccine decisions aren’t one-size-fits-all. Here’s how risk factors might influence your shelter’s protocols:
Geographic disease prevalence. Leptospirosis is common in warm, wet climates and areas with wildlife or standing water. Canine influenza outbreaks tend to cluster in areas with high-density boarding, daycare, or sheltering operations.
Current Outbreaks. If canine influenza hits your region or a neighboring shelter, the benefits of including this optional vaccine in your standard protocols may outweigh the costs, but as outbreaks resolve you might discontinue the practice.
Some shelters use a dual-strain Calicivirus vaccine that targets virulent-systemic strains. The problem? It’s a killed vaccine, so it needs two doses and takes weeks to provide protection. Unless you’re actively battling virulent-systemic Calicivirus outbreaks, stick with the standard modified-live vaccine at intake.
Tables 1 and 2 summarize recommendations for dogs and cats in shelter environments.
Table 1: Canine Vaccines for Shelters
| Vaccine | When to give | Type | Frequency | Age considerations | |
| Often part of combination DAP vaccine, +/- parainfluenza | Distemper | At intake | Injectable, modified-live | Once at intake unless younger than 5 months old, then give every 2 weeks while in shelter. | Historically recommended to start as early as 4 weeks. New neonatal vaccination recommendations suggest giving as early as birth in high-risk settings. |
| Adenovirus | |||||
| Parvovirus | |||||
| Sometimes included in injectable “DAPP” combo and/or intranasal combined with Bordetella | Parainfluenza | At intake | Injectable or intranasal, modified-live | Once at intake | None |
| Bordetella | At intake | Intranasal or oral | Once at intake | None | |
| Rabies | Prior to live outcome | Injectable, killed | Safe to give at any age but not typically recognized before 12 weeks. Legally mandated in most places for all dogs older than 5 months. | ||
| Leptospirosis4-serovar | OPTIONAL As indicated by local risk; endemic areas or rodent exposure. | Injectable, killed | Series of 2 vaccines given 2-4 weeks apart. | Start at 6-12 weeks of age (refer to vaccine label). | |
| Canine InfluenzaH3N2, H3N8 | OPTIONAL Based on local outbreaks; boarding/transport; regional prevalence. | Injectable, killed | Series of 2 vaccines given 2-4 weeks apart. | ||
| Lyme | Not recommended | ||||
| Giardia | Not recommended | ||||
| Ringworm | Not recommended | ||||
| Rattlesnake | Not recommended |
Table 2: Feline Vaccines for Shelters
| Vaccine | When to give | Type | Frequency | Age considerations | |
| Often part of combination HCP/FVRCP vaccine with Calicivirus | Herpesvirus (Feline Viral Rhinotracheitis) | At intake | Injectable, modified-live | Once at intake unless younger than 5 months old, then give every 2 weeks while in shelter. | Historically recommended to start as early as 4 weeks. New neonatal vaccination recommendations suggest giving as early as birth in high-risk settings. |
| Calicivirus | |||||
| Panleukopenia (feline parvovirus) | |||||
| Rabies | Prior to live outcome | Injectable, killed or live; Canarypox vector | Safe to give at any age but not typically recognized before 12 weeks. Legally mandated in many places for all cats older than 5 months. | ||
| Bordetella | OPTIONAL At intake if identified as major contributor to respiratory disease cases. | Intranasal | Once at intake | None | |
| Available only in combination with RVRCP vaccine products. | |||||
| Chlamydia felis | OPTIONAL At intake if identified as major contributor to disease cases. | Injectable, modified-live | At intake; follow label directions. | ||
| FeLV (Feline Leukemia) | OPTIONAL | Injectable, live Canarypox vector or killed | Series of 2 vaccines given 2-4 weeks apart. | Refer to vaccine label. | |
| FIV(Feline Immunodeficiency Virus) | Not recommended | ||||
| FIP(Feline Infectious Peritonitis) | Not recommended | ||||
| Giardia | Not recommended | ||||
Vaccines for Rabbits in Shelters
Vaccination of rabbits is a relatively new consideration in the United States, especially in shelter settings. But for anyone who admits rabbits, it needs to be a consideration. Since 2018 Rabbit Hemorrhagic Disease Virus (RHDV2) has spread rapidly, causing significant deaths among wild rabbits as well as deaths of pet rabbits in home and shelter settings. Think of it as a rabbit pandemic: as a novel virus it can spread rapidly in population settings and has a very high mortality rate. Even so, use of the vaccine in shelter settings is a nuanced consideration, as rabbits will not be immunized until 7-14 days after their second vaccination.
The vaccine should be considered for use by shelters located in geographic areas with known cases of RHDV2 in wild or domestic rabbit populations.
Table 3: Rabbit Vaccines for Shelters
| Vaccine | When to give | Type | Frequency | Age considerations |
| RHDV2 (Rabbit Hemorrhagic Disease Virus 2) | OPTIONAL At intake | Injectable, killed | Series of 2 vaccines given 2-4 weeks apart. Follow label directions. | Follow label directions. |
| Myxomatosis | Not recommended (United States) |
Vaccines for Ferrets in Shelters
Ferrets have a high rate of adverse reactions to vaccines, so the question of whether to vaccinate in the shelter environment warrants careful consideration. Only vaccines that are labeled as safe and effective in ferrets should be used.
Ferrets are highly susceptible to canine distemper, which is almost always fatal. Distemper vaccination should be considered in shelters that regularly have cases of distemper (in ferrets or dogs) or consistently have more than 1-2 ferrets in care at any point in time.
Rabies vaccination for ferrets depends on local legal requirements. Because of the risk of adverse reactions it is reasonable for shelters to recommend that adopters discuss this vaccination with their own veterinarian following adoption.
Table 4: Ferret Vaccines for Shelters
| Vaccine | When to give | Type | Frequency | Age considerations |
| Use only ferret-specific canarypox vector vaccines. DO NOT use standard MLV canine vaccines. | ||||
| Canine distemper | OPTIONAL At intake | Ferret-specific, injectable, canarypox vector | Follow label directions. | Follow label directions. |
| Rabies | Not recommended unless legally required | |||
Never Hold an Animal in the Shelter for a Vaccination
With some important exceptions,* one timely intake vaccine is sufficient to protect cats and dogs from some of the worst diseases (as long as they are not exposed before the onset of immunity, as discussed in post 1 . However, even when a repeat vaccination is indicated (see exceptions below), keep in mind that animals should NEVER be held in shelter care solely for the purpose of getting that vaccine. Getting them out of the high risk shelter environment will provide far more risk reduction than an additional vaccination. If you want to close the loop on those vaccines that immunize after 2 doses you can allow animals to return to the shelter from foster or adoptive homes as needed.
*A few pesky exceptions to a single effective vaccination:
- Killed (as opposed to modified-live) vaccines, such as RHDV2, Leptospirosis, or dual strain Calicivirus. In adult animals, these vaccines typically require two doses given 2-4 weeks apart to immunize. I’ll talk more about this in the next post.
- Animals younger than 20 weeks (5 months) of age: juveniles are different. We’ll deep dive into this in Post 3, but in the meantime, know that the young ones need their core vaccines every 2 weeks while they remain in shelter care.
- Modified-live herpesvirus and calicivirus vaccines don’t completely prevent infection, but they reduce disease severity. A second dose 2-4 weeks after the first may boost antibody levels, but here’s the reality: most cats in shelters with endemic URI get sick within 5-10 days of intake, well before a booster would help. Your best protection strategies are spacious housing, a low stress environment, and short length of stay. If a cat happens to be around for a booster, sure, give it. But don’t count on it to solve your URI problem.
The Bottom Line
Vaccinate for real disease threats, not imaginary ones. Give core vaccines at intake. Give rabies before they leave. Add optional vaccines only when local disease prevalence justifies the cost and logistics.
And never, ever hold an animal in the shelter just to finish a vaccine series.
Coming up
Post 3: Vaccine Type and Timing: Why Both Matter for Shelter Animals
Post 4: Vaccine safety, reactions, and addressing common concerns
Post 5: Interactive protocol generator tool
Need Help Updating Your Shelter Vaccine Protocols?
Are you vaccinating based on real disease risk in your community or using a protocol that hasn’t been updated in years?
If your shelter needs help evaluating vaccine protocols, disease risks, or outbreak response planning, Paws to Elevate Shelter Consultation Services provides customized guidance based on current evidence and your facility’s unique needs. Schedule a free consultation call or explore our services to learn how we can support your team.
AI Disclaimer: This blog post was created with the assistance of AI tools and reviewed and edited by Dr. Becky Stuntebeck, DVM, DABVP (Shelter Medicine). It is provided for general informational purposes and does not constitute veterinary advice. Consult with a licensed veterinarian for decisions regarding your animals or facility.
