Hypertension is common in cats. It can be associated with a predisposing disease such as chronic kidney disease or hyperthyroidism, or idiopathic. Idiopathic hypertension is diagnosed when all predisposing causes have been eliminated (and hypertension is documented on 2 separate occasions) and accounts for less than 1/2 of the cats diagnosed with hypertension (about 40%).
Target organs for hypertension are the CNS, kidneys and cardiovascular system. Despite under recognition by clients, several studies have suggested that hypertensive encephalopathy might be present in 30-40% of cats.
Neurologic manifestations of hypertension in cats
Seizures, mentation changes, vestibular signs (central), behavioral changes (disorientation), tremors, sudden collapse, cervical ventroflexion, paraparesis, cerebellar ataxia with hypermetria, cranial nerve deficits and cortical blindness (not retinal blindness). That's quite a list, isn't it?? It's amazing that these signs are the reason for presentation to a vet in only 10-20% of cats!
A small study was recently published in the Journal of Feline Medicine and Surgery that aimed to identify the clinical occurrence of hypertensive encephalopathy in cats. In this study, 31 of 56 cats were diagnosed with neurologic signs associated with hypertension. Retinal lesion were identified in 28 of the 30 cats that under went fundoscopy.
Cats with neurologic signs presented most often with proprioceptive ataxia, some with vestibular ataxia. Additional signs included hiding, disorientation, sleeping in unusual locations, increased and inappropriate vocalization, and increased appetite. Three of the 31 cats had seizures. Neuroanatomic lesion localization was predominantly prosencephalon, second most commonly vestibular signs and lastly spinal cord signs. Many cats had multifocal neurologic signs.
Treatment and Outcome
Amlodipine was used in 22/31 cats. Telmisartan was used in 4/31 cats. The remaining cats received combination therapy. Follow-up was available for 25 of 31 cats. Fifteen cats had complete recovery after starting antihypertensive medications including one cat with severe seizures. Partial improvement was noted in 8/25 cats with residual ataxia or seizures manifesting most commonly. No initial response to treatment was noted in 2 cats with subsequent euthanasia within 1 week of treatment initiation.
Key points:
Feline hypertension is common (they enrolled 56 cats in less than 2 years!)
Neurologic and behavioral signs occurred in more than 1/2 of the cats in this study but clients weren't aware of the significance!
Treatment with antihypertensive medication can result in improvement
Routine monitoring for hypertension is recommended in at risk cats, especially those with neurologic signs!
Reference: https://doi.org/10.1177/1098612X231153357
Thanks for reading! Have a terrific week; I look forward to working with you soon. Remember to sign up for the July CE if you are planning on attending because space is limited!