A Trusted Friend in a Complicated World

These Are the Pet Combinations That Are Most Likely to Hate Each Other

Just like humans, animals have their own unique personalities. When you pair two different species together it can be harmonious—or the clash of the titans. These animal behavior experts know which animals won't pair up and how to help the ones that can live peacefully in your animal kingdom.

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Predator-prey relationships

Caring for the goldfish your kid won at the school carnival is fairly easy unless you have a curious cat waiting with a jar of tarter sauce nearby. It’s not the cat’s fault. But you should definitely keep natural instincts in mind before pairing up different species of pets. “Typically, in pairing we commonly stress predator-prey relationships in multi-species pairings. However, this is not always a factor,” states Brian W. Ogle, assistant professor and program coordinator, Anthrozoology at Beacon College Leesburg, Florida. “Early exposure during an animal’s critical development period can greatly impact their ability to socialize.” For example, Dr. Ogle has two cats that live harmoniously with a rabbit. “This is only successful because my cats were exposed to rabbits as kittens and have grown up with them. Reinforcement of positive behaviors were critical.” Find out the 17 things your cat would tell you if it could.

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There’s more fish in the sea

That cute goldfish prefers a specific habitat that may not jibe with another type of fish. An animals’ habitat plays a huge role in determining if animals can co-exist, especially in the case of fish and reptiles. Habitats aren’t just about who gets the bigger rock to hide under, but things like natural history, eating patterns, and food types. For example, the cichlid fish should only be housed in cichlid communities, and you must know where the little guy comes from before introducing him to another cichlid. “For example, Lake Tanganyika cichlids can only be housed with other cichlids of the same area of origin. The different varieties of these cichlids each have their own unique habitat requirement,” says Dr. Ogle. Look for fish labeled “community” for your aquarium as they do well in groups. However, caution is advised when joining fish that are labeled “aggressive” or “semi-aggressive” labeled fish. Find out 26 secrets your pet store won’t tell you.

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Birds of a feather don’t always flock together

Some animals have distinctions that aren’t easily detectable at first glance. Birds, for example, seem very similar, with the exception of their colorful plumage. Yet, each species has different habitats and unless you’re an experienced bird owner and have the space and capability, Dr. Ogle says don’t mix birds of different feathers. Yes, Polly does want a cracker but he’s not sharing it with a canary.

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Old Mc Donald’s farm

Farm living often renders bucolic images of foals frolicking and cows grazing peacefully in lush green meadows. That’s because farmer Mc Donald knows that some species don’t play nice in the barnyard. “A surprising combination that does not work well together for most pet owners are ducks and chickens,” says Dr. Ogle. “They require vastly different habitats and physical needs.” Another odd couple is the rooster and drake (male duck). They can be aggressive in a flock. “Turkeys and chickens also have to be managed carefully. The main concern here is a parasitic infection known as blackhead disease,” says Dr. Ogle. As far as livestock goes, donkeys aren’t too keen on dogs and need to be introduced to each other carefully. Find out more “facts” about animals you have all wrong.

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Housing herps

Reptiles and amphibians are in the herps family but not all should share a table at the family reunion. Some reptiles carry bacterial diseases that are usually harmless to them but could be harmful to another species. “This is especially true for animals that come from very different areas of the world and live in very different climates,” says Dr. Ogle. It is not recommended mixing animals that do not naturally exist in the wild or share similar requirements in regard to climate, space and nutrition.” Reptiles have a difficult time communicating with other animals that don’t share their communication methods. This results in unnecessary stress for both animals trying to coexist. “For example, you could not easily house an iguana with a desert tortoise due to their vastly different environmental needs. The same would go for a bearded dragon and tree frogs.

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Toxic relationships

Some popular amphibians like the fire-belly toad and fire salamander produce a toxin that can be harmful to other amphibians or reptiles. “Even if the other animal does not attempt to eat their roommates, the build-up of toxins in the habitat can impact the other animal,” warns Dr. Ogle. Toxins from other animals isn’t your only worry. Your backyard could contain toxins harmful to dogs too.

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Building your pack

“When choosing to pair pets together in the same home, or as I like to call it ‘building your pack’ it’s important to develop a strong understanding of your pets’ personality traits such as focus characteristics, social style and experience level,” says Jessica O’Neill, canine behavior specialist and inventor of the JWalker dog harness. O’Neil recommends starting with one pet and creating a clear profile of that pet. Of course, that will take a bit of time so you can observe how your pet lives in his or her environment. Is your pet focused on their environment, the pack, you, social interaction, or a combination of these things? What is their social style? Are they high-strung, rough, calm, nervous, distant, etc.? What is your pet’s experiences with other animals been like? There’s a lot of information to collect. Some animals just can’t be roommates based on natural factors but if you are thinking of pairing a cat and a dog, for example, certain skills and styles will complement each other and some will be a bad match. “For instance, pairing an introvert, environment-focused cat with a social, rough playing dog will not likely be an easy combination. Whereas a pairing a tolerant, owner-focused dog with balanced social skills and a young social dog with a rough play style may help prove to be an excellent combination,” says O’Neill. Even if the two animals become best buds, they will still require their own “safe” place to retreat from each other. “Treat each pet as an individual as well as a member of the pack,” advises O’Neill. Here are 50 more animal secrets that may help.

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Jabborwock, meet Lucy

Introducing unfamiliar animals to each other isn’t something that should be done hastily. In fact, the animals shouldn’t even meet face-to-face until they accustomed to each other’s scents. “Keep the animals in separate rooms where they can smell one another, but cannot make physical contact. Once they feel comfortable in the space for some time, switch the two animals,” says Dr. Ogle. Now, the animals can become more familiar with the other animals scent without making physical contact. Do this as many times as possible. The goal is for the animals to appear nonreactive to the other animal’s presence. Next step, is to introduce them through a barrier. A closed bathroom door allows the animals to smell each other and interact with limitations. If that process goes well, use a gate or cage, depending on the size of the animal. “Once the two animals have successfully been introduced, it is important to redirect any negative or aggressive behaviors and continuously reward positive behaviors,” instructs Dr. Ogle. “Your home should also be designed in a way that each of the animals have their own space that is theirs alone. This will allow them to retreat when necessary, but engage with the others on their own terms.”

Lisa Marie Conklin
Lisa Marie Conklin is a Baltimore-based writer who writes regularly about pets and home improvement for Reader's Digest. Her work has also been published in The Healthy, Family Handyman and Taste of Home, among other outlets. She's also a certified personal trainer and walking coach for a local senior center.