Preventive Care for Outdoor Cats

Cats that spend time outdoors are exposed to several hazards: fights, injuries, toxins, becoming lost or trapped, and exposure to parasites and infectious diseases. In addition, free-roaming cats present risks to native wildlife. Most veterinarians recommend that cats stay indoors, and the American Veterinary Medical Association (AVMA) encourages client education about the dangers of allowing cats free-roaming access.¹ When clients are unable or unwilling to keep cats indoors, veterinarians can offer preventive care measures to reduce risk for disease.

Preventive care measures typically include appropriate vaccinations² and parasite control. While all pet cats are at risk for parasites, ongoing exposure is more likely in those that spend time outdoors. Both endo- and ectoparasites are common, but most can be treated or prevented.³ Regular fecal examination, typically 2 to 4 times in the first year of life and q6–12mo in adults, is recommended. Products should be selected based on probable parasite exposure, ease of use, and efficacy.

Related Article: Early-Age Spay/Neuter

• If applicable, follow state and local regulations.
  • Vaccination for cats is mandatory in some areas of the country and discretionary, but highly recommended, in others. 
• In general, vaccinate kittens ≥3 months of age, then 1 year following first vaccination, then q1–3yr, depending on vaccine type and regulations.
  • One vaccine brand (Continuum; continuum3.com) is licensed for boosters q4yr but may not be universally accepted. Another brand (Purevax) is licensed for ≥8 weeks of age, but local regulations need to be observed.³

• Vaccinate kittens at 6–8 weeks of age and then q3–4wk until ≥16 weeks of age.
  • This is based on research demonstrating maternal antibody interference with vaccine response in some kittens 12–16 weeks of age.⁴
  • Injectable vaccines are preferable to intranasal.
• Repeat vaccination 1 year later and then q3yr.    
  • Although outdoor cats may be at increased risk for exposure, annual vaccination is not necessary or recommended.

• For viral respiratory disease (common), vaccinate all kittens using the same schedule as for panleukopenia virus.
  • More frequent vaccination (q1–2yr) may be considered if there is heavy or frequent exposure to other outdoor cats.

• Before vaccination, screen kittens and cats with an ELISA test.
• Provide initial vaccine series (ie, 2 doses).
  • This can be as early as 8 weeks, depending on product.
• Repeat vaccination 1 year later, then follow manufacturer recommendations.
• Consider the risk status of each patient when determining whether annual revaccination is necessary.
  • One product (Nobivac) is licensed for q2yr administration.

• Screen kittens and cats with ELISA test before vaccinating.
• For the initial vaccine series, administer 1 dose q2–­3wk for 3 doses, starting as young as 8 weeks of age.
• Annually revaccinate at-risk cats.
  • FIV exposure is associated with outdoor cats, as transmission often occurs as a result of fighting wounds.
  • Vaccination may prevent infection, although not all clades (ie, subtypes) are included in the vaccine; cross-protection against all clades is not guaranteed. 
  • Note that use of FIV vaccine is controversial because of concerns with efficacy and interference with currently available FIV antibody tests.

• Note that these intestinal parasites can cause significant disease, especially in kittens, and have zoonotic potential.
• Treat kittens at 2, 4, 6, and 8 weeks of age.
• Treat older kittens and cats twice, 2 weeks apart; continue with monthly, year-round administration.
  • Many effective products can be administered orally or topically.
  • Note that it is difficult to prevent exposure in outdoor cats, so regular anthelmintic treatment is recommended.

• Note that outdoor cats may ingest fleas and rodents, which can lead to tapeworm infection.
• To decrease likelihood of infection, keep patient on adequate flea control.
• Treat when proglottid shedding is seen; in some outdoor cats with recurrent tapeworms, q2–4mo is sufficient.
  • While most cats are asymptomatic, intestinal obstruction and other clinical signs have been reported.

Control heartworms

• Administer monthly prevention with oral or topical products for all cats in areas where canine heartworm disease is present.
  • Diagnosis is more difficult in cats than in dogs; both false-positive and false-negative results are possible with currently available tests.

Related Article: Cats vs Heartworms: How Real Is the Threat?

• Provide year-round protection against both fleas and ticks.
  • In addition to causing pruritus and flea allergy dermatitis, fleas are potential vectors of Bartonella spp, tapeworm infection, and Rickettsia felis.    
  • While grooming, cats often remove ticks before they can attach; however, ticks can carry Ehrlichia, Anaplasma, Neorickettsia, Cytauxzoon, and Babesia spp that affect cats.
• Prevent possible Otodectes, Notoedres, Cheyletiella, Demodex, or Felicola spp infections with an effective flea and tick product.
  • Some mites are more difficult to treat and require alternative measures.

• Strongly encourage owners to microchip their outdoor cat.
  • A microchip can be critical for outdoor cats that become lost, injured, or transported to shelters or veterinary clinics.
  • If the microchip is not an option, encourage owners to provide a safety (breakaway) collar with identification tags.

CRAIG DATZ, DVM, MS, DABVP & DACVN, is adjunct associate professor at the University of Missouri College of Veterinary Medicine. He is also the nutrition and scientific affairs manager of Royal Canin USA. Dr. Datz has spoken at numerous CE conferences, including the NAVC Conference, and is a parasitology, immunology, and infectious disease consultant.