Bird flu causes blindness in cats that drank milk from infected cows at Texas dairy farm - sparking fears the virus is evolving

About two dozen farm cats were stricken with H5N1 bird flu after drinking milk from infected cows, leaving some blind and killing more than half.

The US Centers for Disease Control and Prevention (CDC) announced the cases this week, revealing at least 24 cats on a Texas farm experienced depressed mental states, body stiffness, loss of coordination, blindness, circling, and excessive mucous from their eyes and noses.

A necropsy of the dead animals, some that died in as little as two days after they fell ill, revealed the virus had spread to their lungs, brains, hearts, and eyes. 

Researchers said the infections on the Texas dairy farm raises more concerns about how bird flu is evolving as it jumps from mammal to mammal. 

Cats at a Texas dairy farm became sick after drinking milk from cows infected with H5N1, a bird flu.

Microscopic examinations of cat tissues revealed the following: (A) inflammation and death of brain cells; (B) pneumonia and death of lung cells; (C) inflammation and lesions in heart tissue; and (D) detached retinas in the eyes.

READ MORE: H5N1 strain of bird flu is found in MILK for first time 

 

The World Health Organization said Friday that bird flu, also known as H5N1, has been detected in unpasteurized milk, though pasteurized milk remains safe. 

'While it’s unlikely that people would become infected with bird flu viruses through contact with an infected wild, stray, feral, or domestic cat, it is possible—especially if there is prolonged and unprotected exposure to the animal,' the CDC shared in the announcement.

'Sick animals may be able to transmit influenza virus to people in their saliva, feces or droppings, and other body fluids.'

The CDC obtained the bodies of two cats, as well as samples of milk from the cows.

The agency also examined tissue samples from six of the cows that had died - three were euthanized, and three had died from their illness.

Testing revealed that all of the animals had been infected with H5N1 bird flu. Specifically, they had the kind designated 2.3.4.4b, a highly pathogenic variety that killed a dolphin in Florida recently.

In the cats, scientists found some hemorrhaging in the back of their skulls, as well as brain hemorrhaging. Otherwise, though, the animals looked normal. 

The examination revealed that the cats had microscopic lesions in their brains, lungs, and hearts. 

Pictures taken of the cats at the farm show the animals drinking milk from a designated bowl, as well as directly from teh cow.

Following the felines' deaths, the CDC also tested the cows, finding puzzling symptoms as well.

Some of them that died were producing normal milk before they succumbed to illness, and some of the cows had tiny lesions in their mammary glands -  an unusual symptom. 

H5N1 has been spreading among cattle in the US recently.

The virus seems to spread from animal to animal species, but it has not been shown to spread among people so far. 

Bird flu has surged in cows and chickens throughout the US, with animals in 29 farms across eight states becoming affected, according to the CDC.

The situation has gotten so serious that Dr Darin Detwiler, former FDA and USDA food safety advisor, told DailyMail.com that Americans should avoid rare meat and runny eggs while the outbreak in cattle was ongoing, as improperly cooked animal products are more likely to carry viruses and bacteria.

Avian influenza A(H5N1) first emerged in 1996 but since 2020, the number of outbreaks in birds has grown exponentially, alongside an increase in the number of infected mammals.

The strain has led to the deaths of tens of millions of poultry, with wild birds and land and marine mammals also infected.

Earlier this month, a dairy farm worker in Texas became the second-ever American to become infected with bird flu. The CDC states that the patient had a 'mild' infection with just one symptom - inflammation of the eye - and has reported to be isolated and 'recovering well.'

When cows on the dairy farm got sick, the cats got sick just one day later. More than half of the approximately 24 cats on one farm died within three days

They are also being treated with the drug oseltamivir, or Tamiflu, and are not thought to have passed the virus on to anyone else.

Dr Wenqing Zhang, head of the WHO's global influenza program, said: 'The case in Texas is the first case of a human infected by avian influenza by a cow.'

There is no evidence that bird flu is spreading among humans. 

But scientists and public health experts have expressed concern that it could happen.

Mutations to viral DNA can make it easier for a virus to jump hosts, as has happened with other viral pandemics like COVID-19.

For now, experts advise fully cooking chicken and beef products, and absolutely avoiding raw (unpasteurized) milk.