Yes, it is completely safe to give Capstar to an opossum! This is standard to give most mammals upon intake! (Although in wildlife it is used less for fleas, and more so for maggots and fly eggs).
Opossum’s can be given many of the same meds as cats actually, like Revolution and Frontline, certain wormers, etc.
For dosing of Capstar, try to gauge his weight - if he’s a smaller guy (5-6 lbs or less), then only give half a pill. If he’s a bigger (around 10lbs), then one whole pill. If you need any help with judging this, try to snap a picture of him and I would be happy to help!
You can crush it up and mix it with applesauce, yogurt, or scrambled eggs. Or you can take the whole pill and shove it in a sardine (in water) or in a grape - opossums LOVE grapes!
I am not entirely sure how often you can give it, as we usually only give it the first 1-3 days since like I said, it is mostly used for maggots, and we rely on topicals like Revolution for the primary flea preventative.
However, I imagine 1-3x a week would be safe though if you wanted to keep him treated while he’s around. Opossums are transient, so he will likely only stick around for only 1-3 weeks.
If you need a cheaper source for Capstar, I would be happy to share some websites that rehabbers typically purchase Capstar from.
You might also want to treat your yard though, too. As with any flea treatment, it takes treating the animal and the environment!
The typical recommendation is food grade Diatomaceous Earth. Just sprinkle it around the yard, dust it on your porch, etc. Reapply as necessary or when your yard gets wet.
Thank you so much for caring for this little guy! Opossums receive a lot of unreasonable disdain over their “quirky” appearance (to put it nicely ), but they are VERY beneficial to coexist with!!!
Unfortunately, like any animal, they can bring around fleas - but they are otherwise one of nature’s best means of pest control! They eat snails, cockroaches, venomous snakes, and a truly mind boggling amount of ticks! They are ticks primary predator, in fact!
Their unusually low body temperature also makes them highly resistant to disease, and they are virtually incapable of contracting rabies! They are also very docile toward both animals and humans!
So again - thank you. People routinely kill, cruelly relocate, or call animal control to euthanize opossums on their property if they even suspect it has fleas.
We need more people like you in the world willing to coexist with our native wildlife!
Also - if the fleas ever look really bad, try to check the color of his nose.
Opossums are relatively susceptible to flea anemia, so if you see his nose looking very, very light and pale, anemia is indicated.
If that hapoens, I would be happy to help connect you with a rehabber or wildlife center in your area.
Or, there is a cheap supplement that you can purchase at basically any grocery store that you can give him if you’d be willing to feed/offer him treats for about a week to help correct the problem so that he’s good as new.
Sorry to revive this old thread, but apparently my comments here show up in Google searches and I am receiving messages about it almost every month now.
So for future reference (as I am in here irregularly), my suggestion is to go on Facebook and do a search for “opossum rehab” and “opossum rescue,” and request to join a couple of the private groups. OCAR/Opossum Care and Rescue is one that comes off the top of my head right now.
You can ask many questions in these groups, including flea control and worming treatment for regular backyard visitors, though I would caution about trying to only take advice from a rehabber in the group (some non-rehabber members are very knowledgeable and experienced, but without being able to discern what’s good information and what’s not, it’s best to rely on someone who is actually licensed).
And speaking of rehabbers, since this is another question I’m also receiving most frequently, these groups can also help you locate a local rehabber or credible rescue/sanctuary.
However, if your situation is time sensitive (injury, illness, or babies), typically doing a search of your state and “wildlife rehabbers/Rehabilitators” will yield results.
Typing in your state/local area/nearest city and “wildlife rescue,” “wildlife rehab” and “[specific species] rescue/rehab” can also help you find a rescue or sanctuary near you or that serves your area.
And here is an additional state-by-state resource -
If you find babies, DO NOT feed them or give them water while you await a response by a rehabber or rescue. Even when tiny, they can go without food and water for 24 hours or so usually. I know it seems counterintuitive, but this is the best course of action until someone who is licensed can take over their care.
As soon as you find the babies, it is absolutely critical that they be gently warmed up. The best/easiest and quickest-but-safe way to do this is to use your own body heat (skin-to-skin).
Once the babies are warmed up a bit, place the babies in a box with a heating pad on LOW under half the box (half so the babies can escape the heat if necessary). If your heating pad has an auto shut off safety feature, then be sure to check frequently to ensure it is still on.
If you do not own a heating pad, then fill a sock with microwaved rice, or put a water bottle with hot water in a sock, and place it on one side of the box (though you need to keep reheating).
Place a soft fabric in the box. By soft, I mean something fleece or cotton (tshirts, soft blankets, etc), not terry cloth or towels/rags, as these can catch on their nails. Place the fabric under them, and also loosely over them to help trap their body heat better.
Place the box in a dark and quiet area and check frequently. Do not unnecessarily disturb, but regularly check their body temperature. They should feel just slightly warm (if they are too warm, move them away from the heat source to the other side of the box and monitor).
If holding for more than a few hours, then you should “stimulate to eliminate.” Babies need Momma’s help going to the bathroom, and you need to act as their surrogate or their bladder can rupture (excruciatingly painful way to die).
Hold them upright in one hand, and dampen a cotton ball or soft tissue with warm water. Then, gently rub their genital area from genital-to-tail strokes until they eliminate *and are done eliminating.* Keep extra damp tissues/cotton balls ready for when they start going so you can quickly grab a clean one and still continuously stroke while they eliminate (especially for poop). Do this every 2-3 hours (they should be completely empty after a few times since you shouldn’t be feeding or watering, so try but don’t force it after they’ve eliminated a few times the longer you have them).
Wear gloves if you have them, but if not (and even if you do!), be sure to throughly wash your hands after handling (20-30 seconds). Most baby opossums aren’t going to be carry any significant zoonotic (transferable to humans) disease, but please always practice safe hygiene!
Also - please understand that baby oppossums younger than about ~40-60 days (you can Google age charts for a rough idea) are very difficult to keep alive. Do all you can to get them to someone experienced ASAP and to sustain them in the mean time, but don’t be too hard on yourself if they don’t make it. Very young opossum babies really need their mother for survival most of the time.
And please do not “raise” them yourself. Babies are always a challenge to keep alive, and opossums are highly susceptible to specific diseases that are directly caused by insufficient (even if well-intentioned) care. Always find someone who is licensed to give them the best chance of survival.
Thank you for caring for your local wildlife!
(As a side note, much of the orphaned baby advice generally works for most baby animals, especially pinky or very young mammals).
I started feeling terrible after realizing the other day that I’d missed a bunch of these messages over the last 6 or so months since I’ve been hospitalized on and off since January and haven’t really been on here.
I’m surprised at how many people are finding this thread through Google!
So I just thought adding more resources and critical information to this thread would be more helpful in the long run