We were contacted by a reader who was trying to determine why her guinea pig was "favoring his right eye" or, rather, tilting his head to the left. By all other appearances he was okay: playful, vocal, eating well, and so forth. But the head tilt seemed to have had a sudden onset a couple of weeks prior to her contacting us.
Two important facts stood out in her e-mail: she has rowdy bunnies who sometimes play rough, and her guinea pig spends a lot of time sitting in a box of hay. Was he injured? Sick? Something else?The head tilt could be symptomatic of three categories of problems. I'll briefly discuss each one, but want to caution folks that head tilts should not be regarded with a "wait and see" approach. Prompt veterinary diagnosis is needed; nothing substitutes for a hands-on exam by a vet that specializes in small exotic animals.
Eye problems can be a result of injury or a congenital condition (e.g., cataracts, blindness). If he scratched his eye on hay (like a particularly stalky piece), it would interfere with his vision as the cornea tries to heal. Scratched corneas can become infected or ulcerated. When left untreated for very long, you can wind up with messy, expensive problems to treat. Until the eye heals, a guinea pig may tilt its head in favor of the "good eye" so that it can see what's going on. If the problem is due to cataracts or blindness, a guinea pig will acclimate to the condition, which may or may not include some degree of head tilt.
This includes ear mites and ear infections. Infections, when left undiagnosed for too long, can spread into bone and/or brain, making them difficult, time-consuming, and expensive to heal -- if they can be healed at all. I've seen a couple of pigs surrendered to our rescue with previously undiagnosed ear infections that spread to the brain in spite of our vets' immediate efforts to treat the infections. The neurological problems are difficult to see and should not be prolonged. The misery of guinea pigs with ear mites and ear infections is palpable, partly because the problems have had several days to set in before most owners can see actual symptoms of discomfort.
For guinea pigs who are by themselves or living with other guinea pigs, head injuries are rare; although playful guinea pigs can get rambunctious, they don't play so rowdy that if they hit the side of the cage they do any serious damage. However, guinea pigs playing with bunnies is a different affair. Bunnies can be very ornery with their back feet, which are the center of their physical power. If those feet make contact with a guinea pig's head, the consequences range from a concussion to an even more serious injury with long-lasting neurological problems. For this reason, guinea pig experts say that while piggies and bunnies make good neighbors, they don't make good roommates or unsupervised playmates.
Again, all these problems require a vet's immediate attention. In the cases of infections and mites, catching something early means the cost of a vet visit, drops and antibiotics, and about two to four weeks (typically) of treatment. Catching something too late becomes a matter of several weeks (or months) of treatment, and several hundred dollars or more in vet visits, diagnostics (like X-rays), and, potentially, surgeries. Even more important, the longer you wait to go to the vet, the longer you prolong your guinea pig's discomfort -- and the pain and stress only increase when your pet gets sicker, has to endure multiple car rides to the vet, and cope with exams, diagnostics, surgery and anethesia, and post-op recuperation.
In the case of our reader at the beginning of this post, her guinea pig turned out to have a scratched cornea. With a short course of drops and ointment, he was back to his old self in about a month's time. And his mom switched him to softer, second-cut timothy hay.