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  • By Dr. Lisa Silk

Why you need to keep your pets’ vaccines updated

This past year has been a global nightmare. While we are being vigilant about our own health, we need to remember the health needs of our pets. Having worked in many states and countries, I can confirm there are extra stresses here on Guam for our pets. And now we have an added stress that dogs can contact Covid-19.

There is a coronavirus vaccine for dogs, but it is not the same coronavirus as Covid. Most veterinarians do not vaccinate for this as it causes very mild gastrointestinal symptoms.

As of now, there are no Covid vaccines for animals. While it has been shown that some species can contract Covid, it seems to be a very low number and does not seem to be passed on to people.

Researchers are watching closely the possibility of Covid mutating in infected animals and then being passed to humans.

I know we are all struggling financially, but we must continue to keep our pets updated with their preventions and vaccines— especially since I noticed a horrible outbreak of parvo when we went into quarantine. I thought it would be good to remind everyone of the health protocols we should be following for our pets.

Cats and dogs have many challenges not encountered in other countries and I am hoping to make it more clear why we need to do the yearly testing and vaccinating here on Guam.

Regardless of where you live, the first visit to the veterinarian should be at seven to eight weeks. At this visit, we check the fecal for intestinal parasites, do an exam and do their first vaccine. If they are positive for internal worms or external fleas, lice or other parasites, they are dewormed and given a topical parasite preventative.

It is very important to tell your veterinarian if your cat lives inside or outside. While cats love to be outside, it isn’t safe here on Guam. There are many stray dogs and cats outside that pose a threat to our pets. They can become very territorial and there can be a lot of fighting.

The stray cat population has a very high rate of FIV (feline immunodeficiency virus). This virus behaves in the body as the HIV virus in humans. But the good news is the FIV virus is not contagious to humans. It is passed from cat to cat by fighting and by birth. Either transplacental, or after birth through the milk.

There is no vaccine for FIV so we need to follow preventative measures that will decrease the number of positive cats in the population. The best and first way to start is to spay and neuter as many as possible because, as stated earlier, the virus can be transmitted by the mother and unneutered males spread it by fighting.

Kittens and new cats coming into the household need to be tested and if positive, kept in the house at all times. After the first visit at seven to eight weeks, the next visit will be three to four weeks later for the second vaccine (FVRCP), flea and other topical parasite preventative and possibly another fecal if outdoor and hunting (cats can be infected by many internal parasites through hunting).

It is important to discuss topical flea and tick prevention. Cats get tapeworms through fleas so it is very important to keep them off your cat. While there are some very effective products (I like bravecto), if your cat is an outdoor cat, I would recommend using topical revolution. I like it because it is also a heartworm preventative and kills ears mites.

Cats are not supposed to be able to be infected by heartworm. However, it is so bad here on Guam. I have diagnosed it twice in cats. Because cats are not hosts for heartworm, there are no treatments for them.

Visit No. 3 will be three to four weeks from visit No. 2. This is the visit where we test for FELV/FIV and give the first rabies vaccine. And they are now ready to schedule their spay or neuter.

It is especially important to spay cats as they are induced ovulators. This means they do not release an egg until being bred and that means they never go out of heat, (it waxes and wanes but they are never out of heat). The uterus becomes engorged with blood and continues to do so until they are bred and pregnant. This can lead to severe anemia and death and a lot of screaming while you are trying to sleep, LOL.

Breast cancer in animals is related to estrogen receptors just like in humans, so spaying them before they start going into heat will decrease their chances of developing breast cancer. The males need to be neutered as they will start spraying the foulest smelling urine on everything to mark territory and attract females. Not neutering also leads to fighting with other males and spreading the FIV virus.

Dogs start their series of vaccines at the same time (seven to eight weeks) but they get booster shots every three to four weeks until they are four months old.

This is due to the parvovirus that can live in the ground for many years and is deadly. Vaccine 1 and 2 are DHPP, which include distemper (this is like the horrible upper respiratory infection cats get with thick yellow nasal discharge, coughing and possible pneumonia); parvovirus, which sloughs off the entire lining of the intestinal tract, can even affect the muscle of the heart and can cause sudden death; hepatitis, which shuts down the liver and parainfluenza which is another respiratory infection, and a flea/tick prevention and heartworm prevention.

Vaccines 3 and 4 include DHPP and leptospirosis, a possible recheck fecal exam, a dose of flea/tick prevention to take home and continue giving every month. This is when spays and neuters can get scheduled. People don't understand how serious tick disease and heartworm can be.

Mosquitoes pick us up baby heartworms from a heartworm positive dog and then bites another dog and injects the baby into the new dog. If the dog is on prevention, the baby mosquito will be killed immediately. If not, the baby will find its way into the heart and start causing irreversible heart damage.

The leptospirosis vaccine is now required due to all the wild pigs infesting the entire island. It is spread in the urine and can infect humans so this is a very important vaccine if your dog goes outside for any reason.

Ticks can cause a variety of diseases. I have seen vomit/diarrhea, blindness, paralysis, severe fever and joint pain.

That is why it is important to have yearly exams on our pets. Please be safe and let us make sure your pets are OK.

(Dr. Lisa Silk is the primary veterinarian and owner of Isla Veterinarian Clinic. Send feedback and questions to


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