Principles of sound shelter health practices include the following:
evaluation of incoming animals at the time of intake to identify specific needs of individual animals
preventive medicine measures, such as vaccination and parasite treatment
testing to detect prevalent infectious diseases
cleaning and disinfection to minimize disease transmission within the facility
stress management and reduction
population management to ensure that the shelter operates within its capacity for care
Protocols for any given shelter are shaped by available resources, needs of the population, and the organization's mandate or mission.
Veterinarians can help by developing programs to move animals through the shelter system efficiently and by providing expedient medical care. Veterinarians can also assist in developing appropriate behavioral rehabilitation programs, so that resident animals can enjoy a high quality of life during their shelter stay. These measures lessen the impacts of infectious disease.
Length of stay in a shelter is the single greatest risk factor for illness. Length of stay also increases stress in animals, which may negatively affect behavior and consequently lower the chances of adoption. Therefore, providing both medical and behavioral care is essential to shelter population health.
Unless the animal shelter is intentionally a long-term, sanctuary-care facility, the focus should always be on moving animals through the shelter system quickly and minimizing their length of stay. In so doing, the animal shelter organization simultaneously maximizes its lifesaving and animal welfare potential.
Intake Evaluation Within the Animal Shelter
Every animal should be assessed for health and behavioral needs as soon as possible after arriving at the animal shelter. If possible, a detailed history should be taken from the surrendering party or anyone who knows the animal (ie, a neighbor or a prior owner identified by microchip scan). This helps to define the animal’s medical and behavioral needs.
The intake evaluation process should include a veterinary examination and reports of observed behavior from all who interact with the animal. Seeing each animal as an individual and planning for what will help that animal facilitates the animal’s pathway through the shelter to a good outcome (eg, adoption or transfer to a partner organization). In some instances, identified problems will be treated at the shelter; in other cases, problems are recorded in detail so the receiving party can provide care and treatment.
No single method of evaluation reliably predicts a dog's future behavior. Shelters should use a combination of resources (eg, surrendering party's report of prior behavior in the home; staff observations of behavior during socialization, walks, playgroups, and medical examinations) to gather information that can help predict the dog's future behavior.
Behavior evaluation tools can help identify a dog's risk for future aggression and the individual behavioral support the dog will need before and after adoption. One frequently used tool is SAFER (Safety Assessment for Evaluating Rehoming) from the American Society for the Prevention of Cruelty to Animals (ASPCA).
Formal behavior evaluations should be performed after the animal has had time to settle into the shelter. Evaluations should be implemented in a standardized manner each time, minimizing the effect of different evaluators, the setting, and other distractions.
Similar evaluation tools are available for assessing cat behavior, including the ASPCA's Feline Spectrum Assessment. A cat's response to an assessment can inform placement options, such as adoption, foster care, behavior modification program, working-cat program, and return-to-field.
Behavior evaluations done in the animal shelter might not identify problem behaviors that can emerge in a home setting or might overemphasize behaviors that will resolve in a home. A behavior evaluation is just one part of assessing an animal's personality; therefore, the results of any single evaluation should be interpreted with caution.
Vaccinations and Antiparasitic Treatments Upon Intake Within the Animal Shelter
All animals entering a shelter should receive the recommended core vaccines upon intake, as well as any vaccines known to be necessary in a given population or community. Vaccination upon intake allows immunologically naive animals to develop immunity against infectious diseases before they encounter an infective dose of a natural disease within the facility. (See the table Vaccine Abbreviations, Full Names, and Notes.)
Vaccine Abbreviations, Full Names, and Notes
Abbreviation | Full Name | Notes |
|---|---|---|
Bb | Bordetella bronchiseptica | Core vaccine for dogs; noncore for cats, though can be considered for cats during canine infectious respiratory disease outbreaks in the shelter |
CAV-2 | Canine adenovirus-2 | Intranasal combination Bb, CPIV, and CAV-2 vaccine recommended during canine infectious respiratory disease outbreaks in the shelter |
CPIV | Canine parainfluenza virus | Administered intranasally in combination with Bb |
DA2LPP | Distemper, adenovirus-2, Leptospira, parainfluenza, parvovirus | Includes Leptospiraa; for use in dogs and puppies ≥ 12 wk old |
DA2PP | Distemper, adenovirus-2, parainfluenza, parvovirus | Lacks Leptospira; for use in puppies ≤ 12 wk old |
FeLV | Feline leukemia virus | Testing recommended to establish FeLV antigen status before vaccination |
FVRCP | Feline viral rhinotracheitis, calicivirus, panleukopenia | Parenteral, modified live virus only Intranasal panleukopenia vaccination ineffective Consider augmenting parenteral FVRCP with intranasal feline herpesvirus-1 and feline calicivirus vaccine for more rapid immune protection; however, postvaccinal clinical signs may be confused with natural infection. |
a Note that bivalent (serotypes Canicola and Icterohaemorrhagiae) and quadrivalent (serotypes Canicola, Grippotyphosa, Icterohaemorrhagiae, and Pomona) Leptospira vaccines are available. | ||
The core vaccines recommended for dogs (see the table Core Canine Vaccination and Antiparasitic Administration in Shelter Medicine) include the following:
canine distemper virus vaccine
canine adenovirus-2 vaccine
canine parvovirus vaccine
Bordetella bronchiseptica vaccine
rabies virus vaccine (inactivated virus)
Except for the rabies virus vaccine, modified live virus vaccines are preferred for the more rapid development of an anamnestic response. Canine parainfluenza virus vaccination is considered noncore; however, it is commonly included in parenteral combination products that contain core vaccines. Canine influenza virus (H3N8 and H3N2) vaccination may be indicated, depending on local prevalence.
Core Canine Vaccination and Antiparasitic Administration in Shelter Medicine
Age Group | Vaccine or Parasite Type | Route of Administration | Timing | Notes |
|---|---|---|---|---|
Vaccinations: | ||||
Dogs and puppies ≥ 3 wk | Bb and CPIV (with or without CAV-2) | Intranasal | At or before intake | Single dose |
Dogs and puppies ≥ 4 wk | DA2PP | Parenteral | At intake Booster q 2–3 wk until 18–20 wk old | Modified live virus vaccines should be used for most rapid onset of immunity |
Dogs and puppies ≥ 12 wk | Leptospira quadrivalent | Parenteral | At intake Booster once 3 wk later | Can use DA2LPP combination initially, then Leptospira quadrivalent alone for booster |
Dogs and puppies ≥ 12 wk | Parenteral | Single dose before release from the shelter or sooner | Required for release from the shelter | |
Dogs and puppies ≥ 20 wk | DA2LPP | Parenteral | At intake Booster once 2–3 wk later | For dogs entering shelter care at ≥ 20 wk old |
Antiparasitic medications: | ||||
Puppies ≤ 12 wk | Oral | At intake | Compounded ponazuril, 50 mg/kg, PO, q 24 h for 3 d, is most effectivea,b Puppies with diarrhea should be bathed daily during treatment | |
Dogs and puppies ≥ 2 wk | Roundworms and hookworms | Oral or topicalc* | At intake Repeat in 2 wk In puppies (and pregnant or nursing dogs) only, continue to deworm q 2 wk until age 16 wk; then q 1 mo until age 6 mo; and then q 3 mo | Common treatment products: pyrantel pamoate (eg, 5 mg/kg, PO, once, then repeated in 7–14 d); fenbendazole (eg, 50 mg/kg, PO, q 24 h for 3–5 d); avermectins (eg, selamectin, 6 mg/kg, topically, q 30 d) |
Dogs and puppies ≥ 6–8 wk | Oral or topical | At intake Repeat q 1 mo or as directed by product | Many products treat both internal and external parasites Use mechanical removal strategies for younger puppies | |
Dogs and puppies ≥ 8 wk | Oral, topical, or injectable | At intake Repeat q 1 mo or as directed by product | 6- and 12-mo injectable moxidectin products are available Many products include treatment for additional internal or external parasites | |
All dogs and puppies | Other internal or external parasites | Treat as appropriate based on testing results | Routine screening not indicated | Screening is recommended for clinically abnormal dogs and puppies |
Abbreviations: Bb, Bordetella bronchiseptica; CAV-2, canine adenovirus-2; CPIV, canine parainfluenza virus; DA2LPP, distemper, adenovirus-2, Leptospira, parainfluenza, parvovirus; DA2PP, distemper, adenovirus-2, parainfluenza, parvovirus. | ||||
a Although an approved commercial formulation of ponazuril is available in the US, it is labeled for horses and requires dilution. In the shelter setting, compounded versions may be preferable for ease of dosing in small animals. In addition, although sulfadimethoxine is approved in the US for coccidiosis in dogs and cats, the duration of treatment is longer. In the author's experience, ponazuril use results in better compliance and does not contribute to a longer length of stay in the shelter setting. b Litster AL, Nichols J, Hall K, Camp J, Mohamed AS. Use of ponazuril paste to treat coccidiosis in shelter-housed cats and dogs. Vet Parasitol. 2014;202(3-4):319-325. doi:10.1016/j.vetpar.2014.03.003 c Common treatment products: pyrantel pamoate (eg, 5 mg/kg, PO, once, then repeated in 7–14 d); fenbendazole (eg, 50 mg/kg, PO, q 24 h for 3–5 d) can be used at the intervals indicated in the Notes column. Avermectins (eg, selamectin, 6 mg/kg, topically, q 30 d) are not recommended to be used more frequently than once a month. | ||||
The core vaccines recommended for cats (see the table Core Feline Vaccination and Antiparasitic Administration in Shelter Medicine) include the following:
feline panleukopenia virus vaccine
feline herpesvirus-1 vaccine
feline calicivirus vaccine
rabies virus vaccine (recombinant or inactivated virus)
Feline leukemia virus vaccination is also recommended in facilities that house kittens and cats in groups.
Bordetella bronchiseptica vaccination is not considered a core vaccine for cats; however, it may be indicated for cats at high risk, such as cats in a shelter facility where there is an outbreak among animals.
Core Feline Vaccination and Antiparasitic Administration in Shelter Medicine
Age Group | Vaccine or Parasite Type | Route of Administration | Timing | Notes |
|---|---|---|---|---|
Vaccinations: | ||||
Kittens ≥ 4 wk | FVRCP | Parenteral | At intake Booster q 2 wk until 16–20 wk old | Ideally, vaccinate 1 wk before shelter entry. Vaccination of kittens < 4 wk old risks cerebellar hypoplasia |
Cohoused cats and kittens ≥ 8 wk | FeLV | Parenteral | At intake Booster once 3 wk later | Optional in individually housed cats |
Cats and kittens ≥ 12 wk | Parenteral | Single dose before release from shelter or sooner | Recombinant or inactivated vaccine | |
Cats and kittens ≥ 20 wk | FVRCP | Parenteral | At intake Booster once 2 wk later | Vaccination of pregnant queens risks cerebellar hypoplasia |
Antiparasitic medications: | ||||
Kittens ≤ 12 wk | Oral | At intake | Compounded ponazuril, 50 mg/kg, PO, q 24 h for 3 d is most effectivea,b Kittens with diarrhea should be bathed daily during treatment | |
Cats and kittens ≥ 2 wk | Roundworms and hookworms | Oral or topicalc* | At intake Repeat in 2 wk In kittens (and pregnant or nursing cats) only, continue to deworm q 2 wk until age 16 wk; then q 1 mo until age 6 mo; then q 3 mo | Common treatment products: pyrantel pamoate (5 mg/kg, PO, once then repeated in 7–14 d); fenbendazole (eg, 50 mg/kg, PO, q 24 h for 3–5 d); avermectins (eg, selamectin, 6 mg/kg, topically, q 30 d) |
Cats and kittens ≥ 6–8 wk | Oral or topical | At intake Repeat q 1 mo or as directed by product | Many products treat both internal and external parasites Use mechanical removal strategies for younger kittens | |
Cats and kittens ≥ 8 wk | Oral or topical | Repeat q 1 mo or as directed by product | American Heartworm Society recommendation: start kittens on heartworm preventative as early as product label allows and no later than age 8 wk | |
All cats and kittens | Other internal and external parasites | Treat as appropriate based on testing results | Routine screening of all cats and kittens not indicated | Screening recommended for clinically abnormal cats and kittens |
Abbreviations: FeLV, feline leukemia virus; FVRCP, feline viral rhinotracheitis, calicivirus, panleukopenia. | ||||
a Although an approved commercial formulation of ponazuril is available in the US, it is labeled for horses and requires dilution. In the shelter setting, compounded versions may be preferable for ease of dosing in small animals. In addition, although sulfadimethoxine is approved in the US for coccidiosis in dogs and cats, the duration of treatment is longer. In the author's experience, ponazuril use results in better compliance and does not contribute to a longer length of stay in the shelter setting. b Litster AL, Nichols J, Hall K, Camp J, Mohamed AS. Use of ponazuril paste to treat coccidiosis in shelter-housed cats and dogs. Vet Parasitol. 2014;202(3-4):319-325. doi:10.1016/j.vetpar.2014.03.003 c Common treatment products: pyrantel pamoate (eg, 5 mg/kg, PO, once, then repeated in 7–14 d); fenbendazole (eg, 50 mg/kg, PO, q 24 h for 3–5 d) can be used at the intervals indicated in the Notes column. Avermectins (eg, selamectin, 6 mg/kg, topically, q 30 d) are not recommended to be used more frequently than once a month. | ||||
In the shelter environment, vaccines are administered at an earlier age and at shorter intervals than they are in the home environment. It may be advisable to vaccinate pregnant animals and animals with mild clinical signs of illness.
The American Animal Hospital Association's 2022 AAHA Canine Vaccination Guidelines (2024 Update) provide specific recommendations for vaccination of shelter dogs and puppies. The 2020 AAHA/AAFP Feline Vaccination Guidelines provide guidance on core vaccines for shelter-housed cats and kittens.
Rabies vaccines should be administered as state law, animal age, and access to a veterinarian allow. Any animal leaving a shelter for adoption, transfer to another organization, offsite adoption event, foster care, or other activity that may expose the animal to new people or animals should be vaccinated for rabies.
Routine administration of broad-spectrum preventive antiparasitic medications and treatments minimizes animal suffering and limits the transmission of certain infections and infestations (see the tables Core Canine Vaccination and Antiparasitic Administration in Shelter Medicine and Core Feline Vaccination and Antiparasitic Administration in Shelter Medicine). Preventive administration protocols should be tailored to infections and infestations of local concern.
Testing every animal for parasites is impractical and expensive. Empirical parasiticide protocols can guide the use of preventive products to protect the population and public health. Protocols should be tailored to the species and life stage of the animals.
Association of Shelter Veterinarian guidelines recommend treating all dogs and cats for roundworms and hookworms upon intake, starting at age 2 weeks, because of zoonotic concerns. They also recommend treatment for coccidia in animals < 6 months old to decrease the risk of environmental contamination and to lessen disease severity.
The Companion Animal Parasite Council maintains parasite forecast maps that can be used to develop parasite prevention protocols that are timely and geographically relevant.
Parasite prevention programs for animal shelters include timely removal of feces and appropriate cleaning and disinfection. Effective parasite control programs also decrease the risk of zoonotic disease transmission.
Most geographical areas in the US and the world are considered at risk for endemic heartworm disease. Heartworm (Dirofilaria immitis) screening for antigens, antibodies, and filariae may be appropriate, depending on local incidence and resources. Preventive mosquito mitigation around the shelter facility is important for limiting the transmission of heartworm disease.
Testing for Prevalent Infectious Diseases Within the Animal Shelter
Infectious disease screening programs—such as testing dogs for heartworm infection and tickborne diseases, testing cats for retroviral diseases, or obtaining ringworm cultures upon intake—may be needed for some populations of animals.
Screening programs should be tailored to reflect local threats and incidence. Screening may enable tracking of animals into early treatment programs to decrease the risk of transmission within the animal shelter or to facilitate population management and decisions related to resource allocation.
When an animal is identified with an infectious disease that poses a likelihood of transmission within the shelter, one of the following steps may be appropriate:
isolation in place with specific treatment, cleaning, and handling protocols
removal from the population (into a hospital, special ward, or foster home, or by euthanasia)
For diseases identified with known incubation periods, the timeline should be researched to ascertain whether the disease was acquired before arrival at the facility or within the facility. Disease transmission within the animal shelter requires a more rigorous population management and disinfection response. An individual animal with a community-acquired infection requires a more individually focused response and may highlight the need for targeted community outreach education and vaccination programs.
Veterinary rounds should be conducted once daily, at a minimum, to visually inspect each animal to ensure that no animal is exhibiting clinical signs of disease or distress. Animal caregivers should maintain a record on each animal to indicate food and water intake, urination and defecation, exercise, attitude, and activity and behavior.
Key Points
Effective health practices in animal shelters include intake evaluations, preventive medicine, disease testing when indicated, appropriate cleaning and disinfection, stress mitigation programs for animals, and managing the population within the facility's capacity for care.
Length of stay is the greatest risk factor for illness in animal shelters; therefore, efficient movement of animals through the system is essential for both welfare and lifesaving outcomes.
Comprehensive protocols for preventive vaccination, parasite treatments, and disease detection should be established; protocols should be tailored to local conditions and population needs.
For More Information
2022 AAHA canine vaccination guidelines (updated 2024). American Animal Hospital Association.
2020 AAHA/AAFP feline vaccination guidelines. American Animal Hospital Association and American Association of Feline Practitioners.
2024 WSAVA vaccination guidelines for dogs and cats. World Small Animal Veterinary Association.
Guidelines for standards of care in animal shelters, 2nd ed. Association of Shelter Veterinarians.
Heartworm guidelines. American Heartworm Society.
Maddie's Infection Control Manual for Animal Shelters. Center for Food Security and Public Health.
2025 annual pet parasite forecasts. Companion Animal Parasite Council.
SAFER and other behavioral assessment tools. ASPCA Pro, American Society for the Prevention of Cruelty to Animals.
ASPCA Feline Spectrum Assessment in 4 steps. ASPCA Pro, American Society for the Prevention of Cruelty to Animals.
Also see pet owner content regarding vaccines.
