I'm Dr. Karing and I would be glad to help you with your questions about Piggy and Twitch. Cats are like humans and each can have a very unique personality: some are fast friends and others no so much. I suspect that Hendrix was more social with Twitch so that Miss Piggy could do her own thing. Now that Hendrix is gone, the dynamic has changed and Miss Piggy may feel stressed without Hendrix and not interested in interacting with Twitch.
I do have a few suggestions. Make sure that you tried Feliway Multicat rather than original Feliway: Feliway Multicat has the feline appeasing pheromone in it instead of the facial pheromone so it works best when you have issues between your cats. http://www.feliway.com/us/NEW-Feliway-MultiCat
I'm not sure which calming treat you tried but I've had good success using VetriScience Composure and I would recommend you give this to both cats twice daily.
It is also important to make sure that your home environment meets your cats' needs. Providing an enriched environment can increase activity, decrease boredom, and prevent many behavior problems that can occur secondary to boredom and stress. Cats need mental stimulation (i.e. especially hyper cats like Twitch); their environment should have opportunities to create their own positive experiences.
- Vertical space is highly desirable for cats and increases the overall space available to the cat. Provide cat trees, preferably with hiding spots, cat perches, and shelves and I believe Piggy will enjoy these and help with any anxiety she may be experiencing from Twitch. Each cat needs their own tree if at all possible and placing them at windows is ideal.
- Scratching is normal cat behavior. Provide acceptable scratching materials (e.g., scratching posts). To train your cat to use the post, reward with treats and praise. Also put catnip, treats, and toys on or near the post. Scratching posts should be tall and sturdy, and made of materials cats prefer (usually wood, sisal rope, or rough fabric). Locate the scratching post next to a window, sleeping area, or another favorite area. Many cats prefer vertical scratching posts; some prefer horizontal ones. If your cats are large, get a large post. http://www.amazon.com/Classy-Kitty-Sisal-Post-17x17x31-5/dp/B00074W3EK/ref=sr_1_12?ie=UTF8&qid=1454951655&sr=8-12&keywords=large+cat+post
- Interactive toys and “hunting” games allow cats to stalk and catch; play several times a day with solitary indoor cats.
- Keep the home environment predictable, but without rigidity or boredom. Make small changes that provide novelty. Studies indicate that cats play best and most often with toys which also use human interaction. Rotated or new toys hold cats' curiosity and interest for longer periods of time.
- Cats in the wild eat 10 to 20 small meals per day. By making all food available in the bowl, foraging time for indoor cats has been reduced to a few minutes per day, as compared with the hours needed for natural foraging. This contributes to the obesity epidemic in cats, which can lead to various disorders, as well as early death. To make feeding more natural for the cat:
- Provide food puzzles/ interactive food toys/ food balls. http://www.amazon.com/TRIXIE-Pet-Products-4590-Activity/dp/B001O8L2UO/ref=sr_1_8?ie=UTF8&qid=1454951437&sr=8-8&keywords=cat+feeding+puzzle
- Homemade food puzzles can be made\a cardboard box, or a plastic beverage bottle with holes cut into it
- Hide food in different places around the house, and in or around new objects so that cats can “hunt” for their food.
- Boxes, bags, and carriers left out provide nice hiding places for cats.
- In a multiple cat household, set up several stations, with litter boxes, food and water, throughout the home. With critical resources available at more than one site, a cat can choose which path to take, and which cat to greet or avoid.
By instituting as many of these suggestions as are practical, taking care to play with Twitch and keep him engaged and making sure each cat has adequate resources so there is no "competition" (i.e. vertical space, food/water stations, litter boxes, etc.) and using the multicat pheromone diffuser (+/- Composure treat if you haven't tried that one yet), I think you will have a good chance at improving the situation between Miss Piggy and Twitch. If that fails, then you may consider use of Royal Canin Calm diet for both cats assuming they don't have any special health concerns that would prevent such a change: https://www.royalcanin.com/products/royal-canin-veterinary-diet-feline-calm-dry-cat-food/3955
Prescription anxiety medication is a last resort if all else fails but you would need to discuss that with your veterinarian after both cats are examined and have routine lab work to fully assess their health prior.
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